Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

16 files changed, 4671 insertions, 0 deletions

diff --git a/vendor/ed25519-compact/.cargo-checksum.json b/vendor/ed25519-compact/.cargo-checksum.json
new file mode 100644
index 0000000..0351ccf
--- /dev/null
+++ b/vendor/ed25519-compact/.cargo-checksum.json
@@ -0,0 +1 @@
+{"files":{},"package":"6a3d382e8464107391c8706b4c14b087808ecb909f6c15c34114bc42e53a9e4c"}
\ No newline at end of file
diff --git a/vendor/ed25519-compact/Cargo.toml b/vendor/ed25519-compact/Cargo.toml
new file mode 100644
index 0000000..23c2b08
--- /dev/null
+++ b/vendor/ed25519-compact/Cargo.toml
@@ -0,0 +1,64 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "ed25519-compact"
+version = "2.0.4"
+authors = ["Frank Denis <github@pureftpd.org>"]
+description = "A small, self-contained, wasm-friendly Ed25519 implementation"
+homepage = "https://github.com/jedisct1/rust-ed25519-compact"
+readme = "README.md"
+keywords = [
+    "crypto",
+    "ed25519",
+    "x25519",
+    "eddsa",
+    "signature",
+]
+categories = [
+    "algorithms",
+    "cryptography",
+    "no-std",
+    "wasm",
+]
+license = "MIT"
+repository = "https://github.com/jedisct1/rust-ed25519-compact"
+
+[dependencies.ct-codecs]
+version = "1.1"
+optional = true
+
+[dependencies.getrandom]
+version = "0.2"
+optional = true
+
+[dev-dependencies.ct-codecs]
+version = "1.1"
+
+[dev-dependencies.getrandom]
+version = "0.2"
+
+[features]
+blind-keys = []
+default = [
+    "random",
+    "std",
+    "x25519",
+    "pem",
+]
+disable-signatures = []
+opt_size = []
+pem = ["ct-codecs"]
+random = ["getrandom"]
+self-verify = []
+std = []
+x25519 = []
diff --git a/vendor/ed25519-compact/LICENSE b/vendor/ed25519-compact/LICENSE
new file mode 100644
index 0000000..212477f
--- /dev/null
+++ b/vendor/ed25519-compact/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020-2021 Frank Denis
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/ed25519-compact/README.md b/vendor/ed25519-compact/README.md
new file mode 100644
index 0000000..6686fa7
--- /dev/null
+++ b/vendor/ed25519-compact/README.md
@@ -0,0 +1,91 @@
+![GitHub CI](https://github.com/jedisct1/rust-ed25519-compact/workflows/GitHub%20CI/badge.svg)
+
+# A compact Ed25519 and X25519 implementation for Rust
+
+* Formally-verified Curve25519 field arithmetic
+* `no_std`-friendly
+* WebAssembly-friendly
+* Compute@Edge-friendly
+* Lightweight
+* Zero dependencies if randomness is provided by the application
+* Only one portable dependency (`getrandom`) if not
+* Supports incremental signatures (streaming API)
+* Safe and simple Rust interface
+
+## [API documentation](https://docs.rs/ed25519-compact)
+
+## Example usage
+
+`cargo.toml`:
+
+```toml
+[dependencies]
+ed25519-compact = "2"
+```
+
+Example code:
+
+```rust
+// A message to sign and verify.
+let message = b"test";
+
+// Generates a new key pair using a random seed.
+// A given seed will always produce the same key pair.
+let key_pair = KeyPair::from_seed(Seed::default());
+
+// Computes a signature for this message using the secret part of the key pair.
+let signature = key_pair.sk.sign(message, Some(Noise::default()));
+
+// Verifies the signature using the public part of the key pair.
+key_pair
+    .pk
+    .verify(message, &signature)
+    .expect("Signature didn't verify");
+
+// Verification of a different message using the same signature and public key fails.
+key_pair
+    .pk
+    .verify(b"A different message", &signature)
+    .expect_err("Signature shouldn't verify");
+
+// All these structures can be viewed as raw bytes simply by dereferencing them:
+let signature_as_bytes: &[u8] = signature.as_ref();
+println!("Signature as bytes: {:?}", signature_as_bytes);
+```
+
+## Incremental API example usage
+
+Messages can also be supplied as multiple parts (streaming API) in order to handle large messages without using much memory:
+
+```rust
+/// Creates a new key pair.
+let kp = KeyPair::generate();
+
+/// Creates a state for an incremental signer.
+let mut st = kp.sk.sign_incremental(Noise::default());
+
+/// Feeds the message as any number of chunks, and sign the concatenation.
+st.absorb("mes");
+st.absorb("sage");
+let signature = st.sign();
+
+/// Creates a state for an incremental verifier.
+let mut st = kp.pk.verify_incremental(&signature)?;
+
+/// Feeds the message as any number of chunks, and verify the concatenation.
+st.absorb("mess");
+st.absorb("age");
+st.verify()?;
+```
+
+## Cargo features
+
+* `self-verify`: after having computed a new signature, verify that is it valid. This is slower, but improves resilience against fault attacks. It is enabled by default on WebAssembly targets.
+* `std`: disables `no_std` compatibility in order to make errors implement the standard `Error` trait.
+* `random` (enabled by default): adds `Default` implementations to the `Seed` and `Noise` objects, in order to securely create random keys and noise.
+* `traits`: add support for the traits from the `ed25519` and `signature` crates.
+* `pem`: add support for importing/exporting keys as OpenSSL-compatible PEM files.
+* `blind-keys`: add support for key blinding.
+* `opt_size`: Enable size optimizations (based on benchmarks, 8-15% size reduction at the cost of 6.5-7% performance).
+* `x25519`: Enable support for the X25519 key exchange system.
+* `disable-signatures`: Disable support for signatures, and only compile support for X25519.
diff --git a/vendor/ed25519-compact/debian/patches/drop-traits-feature.patch b/vendor/ed25519-compact/debian/patches/drop-traits-feature.patch
new file mode 100644
index 0000000..cb26781
--- /dev/null
+++ b/vendor/ed25519-compact/debian/patches/drop-traits-feature.patch
@@ -0,0 +1,21 @@
+Index: ed25519-compact/Cargo.toml
+===================================================================
+--- ed25519-compact.orig/Cargo.toml
++++ ed25519-compact/Cargo.toml
+@@ -37,10 +37,6 @@ repository = "https://github.com/jedisct
+ version = "1.1"
+ optional = true
+ 
+-[dependencies.ed25519]
+-version = "1.5"
+-optional = true
+-
+ [dependencies.getrandom]
+ version = "0.2"
+ optional = true
+@@ -65,5 +61,4 @@ pem = ["ct-codecs"]
+ random = ["getrandom"]
+ self-verify = []
+ std = []
+-traits = ["ed25519"]
+ x25519 = []
diff --git a/vendor/ed25519-compact/debian/patches/fix-autopkgtest.patch b/vendor/ed25519-compact/debian/patches/fix-autopkgtest.patch
new file mode 100644
index 0000000..9d17260
--- /dev/null
+++ b/vendor/ed25519-compact/debian/patches/fix-autopkgtest.patch
@@ -0,0 +1,104 @@
+Index: ed25519-compact/src/ed25519.rs
+===================================================================
+--- ed25519-compact.orig/src/ed25519.rs
++++ ed25519-compact/src/ed25519.rs
+@@ -857,7 +857,7 @@ mod blind_keys {
+ pub use blind_keys::*;
+ 
+ #[test]
+-#[cfg(feature = "blind-keys")]
++#[cfg(all(feature = "blind-keys", feature = "random"))]
+ fn test_blind_ed25519() {
+     use ct_codecs::{Decoder, Hex};
+ 
+@@ -914,6 +914,7 @@ fn test_blind_ed25519() {
+ }
+ 
+ #[test]
++#[cfg(feature = "random")]
+ fn test_streaming() {
+     let kp = KeyPair::generate();
+ 
+Index: ed25519-compact/src/lib.rs
+===================================================================
+--- ed25519-compact.orig/src/lib.rs
++++ ed25519-compact/src/lib.rs
+@@ -15,6 +15,8 @@
+ //! ```rust
+ //! use ed25519_compact::*;
+ //!
++//! #[cfg(feature = "random")]
++//! fn test() {
+ //! // A message to sign and verify.
+ //! let message = b"test";
+ //!
+@@ -40,6 +42,13 @@
+ //! // All these structures can be viewed as raw bytes simply by dereferencing them:
+ //! let signature_as_bytes: &[u8] = signature.as_ref();
+ //! println!("Signature as bytes: {:?}", signature_as_bytes);
++//!
++//! }
++//!
++//! #[cfg(not(feature = "random"))]
++//! fn test() {}
++//!
++//! test()
+ //! ```
+ //!
+ //! ## Incremental API example usage
+@@ -50,6 +59,8 @@
+ //! ```rust
+ //! use ed25519_compact::*;
+ //!
++//! #[cfg(feature = "random")]
++//! fn test() {
+ //! /// Creates a new key pair.
+ //! let kp = KeyPair::generate();
+ //!
+@@ -68,6 +79,12 @@
+ //! st.absorb("mess");
+ //! st.absorb("age");
+ //! assert!(st.verify().is_ok());
++//! }
++//!
++//! #[cfg(not(feature = "random"))]
++//! fn test() {}
++//!
++//! test()
+ //! ```
+ //!
+ //! Cargo features:
+Index: ed25519-compact/src/pem.rs
+===================================================================
+--- ed25519-compact.orig/src/pem.rs
++++ ed25519-compact/src/pem.rs
+@@ -142,6 +142,7 @@ MCowBQYDK2VwAyEAyrRjJfTnhMcW5igzYvPirFW5
+ }
+ 
+ #[test]
++#[cfg(feature = "random")]
+ fn test_der() {
+     let kp = KeyPair::generate();
+     let sk_der = kp.sk.to_der();
+Index: ed25519-compact/src/x25519.rs
+===================================================================
+--- ed25519-compact.orig/src/x25519.rs
++++ ed25519-compact/src/x25519.rs
+@@ -312,6 +312,7 @@ mod from_ed25519 {
+ pub use from_ed25519::*;
+ 
+ #[test]
++#[cfg(feature = "random")]
+ fn test_x25519() {
+     let sk_1 = SecretKey::from_slice(&[
+         1u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+@@ -327,8 +328,8 @@ fn test_x25519() {
+     assert_eq!(output_a, output_b);
+ }
+ 
+-#[cfg(not(feature = "disable-signatures"))]
+ #[test]
++#[cfg(all(not(feature = "disable-signatures"), feature = "random"))]
+ fn test_x25519_map() {
+     use super::KeyPair as EdKeyPair;
+     let edkp_a = EdKeyPair::generate();
diff --git a/vendor/ed25519-compact/debian/patches/series b/vendor/ed25519-compact/debian/patches/series
new file mode 100644
index 0000000..e6b86c6
--- /dev/null
+++ b/vendor/ed25519-compact/debian/patches/series
@@ -0,0 +1,2 @@
+drop-traits-feature.patch
+fix-autopkgtest.patch
diff --git a/vendor/ed25519-compact/src/common.rs b/vendor/ed25519-compact/src/common.rs
new file mode 100644
index 0000000..12f28c5
--- /dev/null
+++ b/vendor/ed25519-compact/src/common.rs
@@ -0,0 +1,90 @@
+use core::ops::{Deref, DerefMut};
+use core::ptr;
+use core::sync::atomic;
+
+use super::error::Error;
+
+/// A seed, which a key pair can be derived from.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct Seed([u8; Seed::BYTES]);
+
+impl From<[u8; 32]> for Seed {
+    fn from(seed: [u8; 32]) -> Self {
+        Seed(seed)
+    }
+}
+
+impl Seed {
+    /// Number of raw bytes in a seed.
+    pub const BYTES: usize = 32;
+
+    /// Creates a seed from raw bytes.
+    pub fn new(seed: [u8; Seed::BYTES]) -> Self {
+        Seed(seed)
+    }
+
+    /// Creates a seed from a slice.
+    pub fn from_slice(seed: &[u8]) -> Result<Self, Error> {
+        let mut seed_ = [0u8; Seed::BYTES];
+        if seed.len() != seed_.len() {
+            return Err(Error::InvalidSeed);
+        }
+        seed_.copy_from_slice(seed);
+        Ok(Seed::new(seed_))
+    }
+
+    /// Tentatively overwrite the content of the seed with zeros.
+    pub fn wipe(self) {
+        Mem::wipe(self.0)
+    }
+}
+
+#[cfg(feature = "random")]
+impl Default for Seed {
+    /// Generates a random seed.
+    fn default() -> Self {
+        let mut seed = [0u8; Seed::BYTES];
+        getrandom::getrandom(&mut seed).expect("RNG failure");
+        Seed(seed)
+    }
+}
+
+#[cfg(feature = "random")]
+impl Seed {
+    /// Generates a random seed.
+    pub fn generate() -> Self {
+        Seed::default()
+    }
+}
+
+impl Deref for Seed {
+    type Target = [u8; Seed::BYTES];
+
+    /// Returns a seed as raw bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Seed {
+    /// Returns a seed as mutable raw bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+pub(crate) struct Mem;
+
+impl Mem {
+    #[inline]
+    pub fn wipe<T: Default>(mut x: impl AsMut<[T]>) {
+        let x = x.as_mut();
+        for i in 0..x.len() {
+            unsafe {
+                ptr::write_volatile(x.as_mut_ptr().add(i), T::default());
+            }
+        }
+        atomic::compiler_fence(atomic::Ordering::SeqCst);
+        atomic::fence(atomic::Ordering::SeqCst);
+    }
+}
diff --git a/vendor/ed25519-compact/src/ed25519.rs b/vendor/ed25519-compact/src/ed25519.rs
new file mode 100644
index 0000000..c00b833
--- /dev/null
+++ b/vendor/ed25519-compact/src/ed25519.rs
@@ -0,0 +1,953 @@
+use core::fmt;
+use core::ops::{Deref, DerefMut};
+
+use super::common::*;
+#[cfg(feature = "blind-keys")]
+use super::edwards25519::{ge_scalarmult, sc_invert, sc_mul};
+use super::edwards25519::{
+    ge_scalarmult_base, is_identity, sc_muladd, sc_reduce, sc_reduce32, sc_reject_noncanonical,
+    GeP2, GeP3,
+};
+use super::error::Error;
+use super::sha512;
+
+/// A public key.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct PublicKey([u8; PublicKey::BYTES]);
+
+impl PublicKey {
+    /// Number of raw bytes in a public key.
+    pub const BYTES: usize = 32;
+
+    /// Creates a public key from raw bytes.
+    pub fn new(pk: [u8; PublicKey::BYTES]) -> Self {
+        PublicKey(pk)
+    }
+
+    /// Creates a public key from a slice.
+    pub fn from_slice(pk: &[u8]) -> Result<Self, Error> {
+        let mut pk_ = [0u8; PublicKey::BYTES];
+        if pk.len() != pk_.len() {
+            return Err(Error::InvalidPublicKey);
+        }
+        pk_.copy_from_slice(pk);
+        Ok(PublicKey::new(pk_))
+    }
+}
+
+impl Deref for PublicKey {
+    type Target = [u8; PublicKey::BYTES];
+
+    /// Returns a public key as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for PublicKey {
+    /// Returns a public key as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+/// A secret key.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct SecretKey([u8; SecretKey::BYTES]);
+
+impl SecretKey {
+    /// Number of bytes in a secret key.
+    pub const BYTES: usize = 32 + PublicKey::BYTES;
+
+    /// Creates a secret key from raw bytes.
+    pub fn new(sk: [u8; SecretKey::BYTES]) -> Self {
+        SecretKey(sk)
+    }
+
+    /// Creates a secret key from a slice.
+    pub fn from_slice(sk: &[u8]) -> Result<Self, Error> {
+        let mut sk_ = [0u8; SecretKey::BYTES];
+        if sk.len() != sk_.len() {
+            return Err(Error::InvalidSecretKey);
+        }
+        sk_.copy_from_slice(sk);
+        Ok(SecretKey::new(sk_))
+    }
+
+    /// Returns the public counterpart of a secret key.
+    pub fn public_key(&self) -> PublicKey {
+        let mut pk = [0u8; PublicKey::BYTES];
+        pk.copy_from_slice(&self[Seed::BYTES..]);
+        PublicKey(pk)
+    }
+
+    /// Returns the seed of a secret key.
+    pub fn seed(&self) -> Seed {
+        Seed::from_slice(&self[0..Seed::BYTES]).unwrap()
+    }
+
+    /// Returns `Ok(())` if the given public key is the public counterpart of
+    /// this secret key.
+    /// Returns `Err(Error::InvalidPublicKey)` otherwise.
+    /// The public key is recomputed (not just copied) from the secret key,
+    /// so this will detect corruption of the secret key.
+    pub fn validate_public_key(&self, pk: &PublicKey) -> Result<(), Error> {
+        let kp = KeyPair::from_seed(self.seed());
+        if kp.pk != *pk {
+            return Err(Error::InvalidPublicKey);
+        }
+        Ok(())
+    }
+}
+
+impl Drop for SecretKey {
+    fn drop(&mut self) {
+        Mem::wipe(self.0)
+    }
+}
+
+impl Deref for SecretKey {
+    type Target = [u8; SecretKey::BYTES];
+
+    /// Returns a secret key as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for SecretKey {
+    /// Returns a secret key as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+/// A key pair.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct KeyPair {
+    /// Public key part of the key pair.
+    pub pk: PublicKey,
+    /// Secret key part of the key pair.
+    pub sk: SecretKey,
+}
+
+/// An Ed25519 signature.
+#[derive(Copy, Clone, Eq, PartialEq, Hash)]
+pub struct Signature([u8; Signature::BYTES]);
+
+impl fmt::Debug for Signature {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_fmt(format_args!("{:x?}", &self.0))
+    }
+}
+
+impl AsRef<[u8]> for Signature {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl Signature {
+    /// Number of raw bytes in a signature.
+    pub const BYTES: usize = 64;
+
+    /// Creates a signature from raw bytes.
+    pub fn new(bytes: [u8; Signature::BYTES]) -> Self {
+        Signature(bytes)
+    }
+
+    /// Creates a signature key from a slice.
+    pub fn from_slice(signature: &[u8]) -> Result<Self, Error> {
+        let mut signature_ = [0u8; Signature::BYTES];
+        if signature.len() != signature_.len() {
+            return Err(Error::InvalidSignature);
+        }
+        signature_.copy_from_slice(signature);
+        Ok(Signature::new(signature_))
+    }
+}
+
+impl Deref for Signature {
+    type Target = [u8; Signature::BYTES];
+
+    /// Returns a signture as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Signature {
+    /// Returns a signature as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+/// The state of a streaming verification operation.
+#[derive(Clone)]
+pub struct VerifyingState {
+    hasher: sha512::Hash,
+    signature: Signature,
+    a: GeP3,
+}
+
+impl Drop for VerifyingState {
+    fn drop(&mut self) {
+        Mem::wipe(self.signature.0);
+    }
+}
+
+impl VerifyingState {
+    fn new(pk: &PublicKey, signature: &Signature) -> Result<Self, Error> {
+        let r = &signature[0..32];
+        let s = &signature[32..64];
+        sc_reject_noncanonical(s)?;
+        if is_identity(pk) || pk.iter().fold(0, |acc, x| acc | x) == 0 {
+            return Err(Error::WeakPublicKey);
+        }
+        let a = match GeP3::from_bytes_negate_vartime(pk) {
+            Some(g) => g,
+            None => {
+                return Err(Error::InvalidPublicKey);
+            }
+        };
+        let mut hasher = sha512::Hash::new();
+        hasher.update(r);
+        hasher.update(&pk[..]);
+        Ok(VerifyingState {
+            hasher,
+            signature: *signature,
+            a,
+        })
+    }
+
+    /// Appends data to the message being verified.
+    pub fn absorb(&mut self, chunk: impl AsRef<[u8]>) {
+        self.hasher.update(chunk)
+    }
+
+    /// Verifies the signature and return it.
+    pub fn verify(&self) -> Result<(), Error> {
+        let mut expected_r_bytes = [0u8; 32];
+        expected_r_bytes.copy_from_slice(&self.signature[0..32]);
+        let expected_r =
+            GeP3::from_bytes_vartime(&expected_r_bytes).ok_or(Error::InvalidSignature)?;
+        let s = &self.signature[32..64];
+
+        let mut hash = self.hasher.finalize();
+        sc_reduce(&mut hash);
+
+        let r = GeP2::double_scalarmult_vartime(hash.as_ref(), self.a, s);
+        if (expected_r - GeP3::from(r)).has_small_order() {
+            Ok(())
+        } else {
+            Err(Error::SignatureMismatch)
+        }
+    }
+}
+
+impl PublicKey {
+    /// Verify the signature of a multi-part message (streaming).
+    pub fn verify_incremental(&self, signature: &Signature) -> Result<VerifyingState, Error> {
+        VerifyingState::new(self, signature)
+    }
+
+    /// Verifies that the signature `signature` is valid for the message
+    /// `message`.
+    pub fn verify(&self, message: impl AsRef<[u8]>, signature: &Signature) -> Result<(), Error> {
+        let mut st = VerifyingState::new(self, signature)?;
+        st.absorb(message);
+        st.verify()
+    }
+}
+
+/// The state of a streaming signature operation.
+#[derive(Clone)]
+pub struct SigningState {
+    hasher: sha512::Hash,
+    az: [u8; 64],
+    nonce: [u8; 64],
+}
+
+impl Drop for SigningState {
+    fn drop(&mut self) {
+        Mem::wipe(self.az);
+        Mem::wipe(self.nonce);
+    }
+}
+
+impl SigningState {
+    fn new(nonce: [u8; 64], az: [u8; 64], pk_: &[u8]) -> Self {
+        let mut prefix: [u8; 64] = [0; 64];
+        let r = ge_scalarmult_base(&nonce[0..32]);
+        prefix[0..32].copy_from_slice(&r.to_bytes()[..]);
+        prefix[32..64].copy_from_slice(pk_);
+
+        let mut st = sha512::Hash::new();
+        st.update(prefix);
+
+        SigningState {
+            hasher: st,
+            nonce,
+            az,
+        }
+    }
+
+    /// Appends data to the message being signed.
+    pub fn absorb(&mut self, chunk: impl AsRef<[u8]>) {
+        self.hasher.update(chunk)
+    }
+
+    /// Computes the signature and return it.
+    pub fn sign(&self) -> Signature {
+        let mut signature: [u8; 64] = [0; 64];
+        let r = ge_scalarmult_base(&self.nonce[0..32]);
+        signature[0..32].copy_from_slice(&r.to_bytes()[..]);
+        let mut hram = self.hasher.finalize();
+        sc_reduce(&mut hram);
+        sc_muladd(
+            &mut signature[32..64],
+            &hram[0..32],
+            &self.az[0..32],
+            &self.nonce[0..32],
+        );
+        Signature(signature)
+    }
+}
+
+impl SecretKey {
+    /// Sign a multi-part message (streaming API).
+    /// It is critical for `noise` to never repeat.
+    pub fn sign_incremental(&self, noise: Noise) -> SigningState {
+        let seed = &self[0..32];
+        let pk = &self[32..64];
+        let az: [u8; 64] = {
+            let mut hash_output = sha512::Hash::hash(seed);
+            hash_output[0] &= 248;
+            hash_output[31] &= 63;
+            hash_output[31] |= 64;
+            hash_output
+        };
+        let mut st = sha512::Hash::new();
+        #[cfg(feature = "random")]
+        {
+            let additional_noise = Noise::generate();
+            st.update(additional_noise.as_ref());
+        }
+        st.update(noise.as_ref());
+        st.update(seed);
+        let nonce = st.finalize();
+        SigningState::new(nonce, az, pk)
+    }
+
+    /// Computes a signature for the message `message` using the secret key.
+    /// The noise parameter is optional, but recommended in order to mitigate
+    /// fault attacks.
+    pub fn sign(&self, message: impl AsRef<[u8]>, noise: Option<Noise>) -> Signature {
+        let seed = &self[0..32];
+        let pk = &self[32..64];
+        let az: [u8; 64] = {
+            let mut hash_output = sha512::Hash::hash(seed);
+            hash_output[0] &= 248;
+            hash_output[31] &= 63;
+            hash_output[31] |= 64;
+            hash_output
+        };
+        let nonce = {
+            let mut hasher = sha512::Hash::new();
+            if let Some(noise) = noise {
+                hasher.update(&noise[..]);
+                hasher.update(&az[..]);
+            } else {
+                hasher.update(&az[32..64]);
+            }
+            hasher.update(&message);
+            let mut hash_output = hasher.finalize();
+            sc_reduce(&mut hash_output[0..64]);
+            hash_output
+        };
+        let mut st = SigningState::new(nonce, az, pk);
+        st.absorb(&message);
+        let signature = st.sign();
+
+        #[cfg(feature = "self-verify")]
+        {
+            PublicKey::from_slice(pk)
+                .expect("Key length changed")
+                .verify(message, &signature)
+                .expect("Newly created signature cannot be verified");
+        }
+
+        signature
+    }
+}
+
+impl KeyPair {
+    /// Number of bytes in a key pair.
+    pub const BYTES: usize = SecretKey::BYTES;
+
+    /// Generates a new key pair.
+    #[cfg(feature = "random")]
+    pub fn generate() -> KeyPair {
+        KeyPair::from_seed(Seed::default())
+    }
+
+    /// Generates a new key pair using a secret seed.
+    pub fn from_seed(seed: Seed) -> KeyPair {
+        if seed.iter().fold(0, |acc, x| acc | x) == 0 {
+            panic!("All-zero seed");
+        }
+        let (scalar, _) = {
+            let hash_output = sha512::Hash::hash(&seed[..]);
+            KeyPair::split(&hash_output, false, true)
+        };
+        let pk = ge_scalarmult_base(&scalar).to_bytes();
+        let mut sk = [0u8; 64];
+        sk[0..32].copy_from_slice(&*seed);
+        sk[32..64].copy_from_slice(&pk);
+        KeyPair {
+            pk: PublicKey(pk),
+            sk: SecretKey(sk),
+        }
+    }
+
+    /// Creates a key pair from a slice.
+    pub fn from_slice(bytes: &[u8]) -> Result<Self, Error> {
+        let sk = SecretKey::from_slice(bytes)?;
+        let pk = sk.public_key();
+        Ok(KeyPair { pk, sk })
+    }
+
+    /// Clamp a scalar.
+    pub fn clamp(scalar: &mut [u8]) {
+        scalar[0] &= 248;
+        scalar[31] &= 63;
+        scalar[31] |= 64;
+    }
+
+    /// Split a serialized representation of a key pair into a secret scalar and
+    /// a prefix.
+    pub fn split(bytes: &[u8; 64], reduce: bool, clamp: bool) -> ([u8; 32], [u8; 32]) {
+        let mut scalar = [0u8; 32];
+        scalar.copy_from_slice(&bytes[0..32]);
+        if clamp {
+            Self::clamp(&mut scalar);
+        }
+        if reduce {
+            sc_reduce32(&mut scalar);
+        }
+        let mut prefix = [0u8; 32];
+        prefix.copy_from_slice(&bytes[32..64]);
+        (scalar, prefix)
+    }
+
+    /// Check that the public key is valid for the secret key.
+    pub fn validate(&self) -> Result<(), Error> {
+        self.sk.validate_public_key(&self.pk)
+    }
+}
+
+impl Deref for KeyPair {
+    type Target = [u8; KeyPair::BYTES];
+
+    /// Returns a key pair as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.sk
+    }
+}
+
+impl DerefMut for KeyPair {
+    /// Returns a key pair as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.sk
+    }
+}
+
+/// Noise, for non-deterministic signatures.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct Noise([u8; Noise::BYTES]);
+
+impl Noise {
+    /// Number of raw bytes for a noise component.
+    pub const BYTES: usize = 16;
+
+    /// Creates a new noise component from raw bytes.
+    pub fn new(noise: [u8; Noise::BYTES]) -> Self {
+        Noise(noise)
+    }
+
+    /// Creates noise from a slice.
+    pub fn from_slice(noise: &[u8]) -> Result<Self, Error> {
+        let mut noise_ = [0u8; Noise::BYTES];
+        if noise.len() != noise_.len() {
+            return Err(Error::InvalidSeed);
+        }
+        noise_.copy_from_slice(noise);
+        Ok(Noise::new(noise_))
+    }
+}
+
+impl Deref for Noise {
+    type Target = [u8; Noise::BYTES];
+
+    /// Returns the noise as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Noise {
+    /// Returns the noise as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+#[cfg(feature = "random")]
+impl Default for Noise {
+    /// Generates random noise.
+    fn default() -> Self {
+        let mut noise = [0u8; Noise::BYTES];
+        getrandom::getrandom(&mut noise).expect("RNG failure");
+        Noise(noise)
+    }
+}
+
+#[cfg(feature = "random")]
+impl Noise {
+    /// Generates random noise.
+    pub fn generate() -> Self {
+        Noise::default()
+    }
+}
+
+#[cfg(feature = "traits")]
+mod ed25519_trait {
+    use ::ed25519::signature as ed25519_trait;
+
+    use super::{PublicKey, SecretKey, Signature};
+
+    impl ed25519_trait::Signature for Signature {
+        fn from_bytes(bytes: &[u8]) -> Result<Self, ed25519_trait::Error> {
+            let mut bytes_ = [0u8; Signature::BYTES];
+            bytes_.copy_from_slice(bytes);
+            Ok(Signature::new(bytes_))
+        }
+    }
+
+    impl ed25519_trait::Signer<Signature> for SecretKey {
+        fn try_sign(&self, message: &[u8]) -> Result<Signature, ed25519_trait::Error> {
+            Ok(self.sign(message, None))
+        }
+    }
+
+    impl ed25519_trait::Verifier<Signature> for PublicKey {
+        fn verify(
+            &self,
+            message: &[u8],
+            signature: &Signature,
+        ) -> Result<(), ed25519_trait::Error> {
+            #[cfg(feature = "std")]
+            {
+                self.verify(message, signature)
+                    .map_err(|e| ed25519_trait::Error::from_source(e))
+            }
+
+            #[cfg(not(feature = "std"))]
+            {
+                self.verify(message, signature)
+                    .map_err(|_| ed25519_trait::Error::new())
+            }
+        }
+    }
+}
+
+#[test]
+fn test_ed25519() {
+    let kp = KeyPair::from_seed([42u8; 32].into());
+    let message = b"Hello, World!";
+    let signature = kp.sk.sign(message, None);
+    assert!(kp.pk.verify(message, &signature).is_ok());
+    assert!(kp.pk.verify(b"Hello, world!", &signature).is_err());
+    assert_eq!(
+        signature.as_ref(),
+        [
+            196, 182, 1, 15, 182, 182, 231, 166, 227, 62, 243, 85, 49, 174, 169, 9, 162, 196, 98,
+            104, 30, 81, 22, 38, 184, 136, 253, 128, 10, 160, 128, 105, 127, 130, 138, 164, 57, 86,
+            94, 160, 216, 85, 153, 139, 81, 100, 38, 124, 235, 210, 26, 95, 231, 90, 73, 206, 33,
+            216, 171, 15, 188, 181, 136, 7,
+        ]
+    );
+}
+
+#[cfg(feature = "blind-keys")]
+mod blind_keys {
+    use super::*;
+
+    #[derive(Clone, Debug, Eq, PartialEq, Hash)]
+    pub struct Blind([u8; Blind::BYTES]);
+
+    impl From<[u8; 32]> for Blind {
+        fn from(blind: [u8; 32]) -> Self {
+            Blind(blind)
+        }
+    }
+
+    impl Blind {
+        /// Number of raw bytes in a blind.
+        pub const BYTES: usize = 32;
+
+        /// Creates a blind from raw bytes.
+        pub fn new(blind: [u8; Blind::BYTES]) -> Self {
+            Blind(blind)
+        }
+
+        /// Creates a blind from a slice.
+        pub fn from_slice(blind: &[u8]) -> Result<Self, Error> {
+            let mut blind_ = [0u8; Blind::BYTES];
+            if blind.len() != blind_.len() {
+                return Err(Error::InvalidBlind);
+            }
+            blind_.copy_from_slice(blind);
+            Ok(Blind::new(blind_))
+        }
+    }
+
+    impl Drop for Blind {
+        fn drop(&mut self) {
+            Mem::wipe(self.0)
+        }
+    }
+
+    #[cfg(feature = "random")]
+    impl Default for Blind {
+        /// Generates a random blind.
+        fn default() -> Self {
+            let mut blind = [0u8; Blind::BYTES];
+            getrandom::getrandom(&mut blind).expect("RNG failure");
+            Blind(blind)
+        }
+    }
+
+    #[cfg(feature = "random")]
+    impl Blind {
+        /// Generates a random blind.
+        pub fn generate() -> Self {
+            Blind::default()
+        }
+    }
+
+    impl Deref for Blind {
+        type Target = [u8; Blind::BYTES];
+
+        /// Returns a blind as bytes.
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl DerefMut for Blind {
+        /// Returns a blind as mutable bytes.
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    /// A blind public key.
+    #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+    pub struct BlindPublicKey([u8; PublicKey::BYTES]);
+
+    impl Deref for BlindPublicKey {
+        type Target = [u8; BlindPublicKey::BYTES];
+
+        /// Returns a public key as bytes.
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl DerefMut for BlindPublicKey {
+        /// Returns a public key as mutable bytes.
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    impl BlindPublicKey {
+        /// Number of bytes in a blind public key.
+        pub const BYTES: usize = PublicKey::BYTES;
+
+        /// Creates a blind public key from raw bytes.
+        pub fn new(bpk: [u8; PublicKey::BYTES]) -> Self {
+            BlindPublicKey(bpk)
+        }
+
+        /// Creates a blind public key from a slice.
+        pub fn from_slice(bpk: &[u8]) -> Result<Self, Error> {
+            let mut bpk_ = [0u8; PublicKey::BYTES];
+            if bpk.len() != bpk_.len() {
+                return Err(Error::InvalidPublicKey);
+            }
+            bpk_.copy_from_slice(bpk);
+            Ok(BlindPublicKey::new(bpk_))
+        }
+
+        /// Unblinds a public key.
+        pub fn unblind(&self, blind: &Blind, ctx: impl AsRef<[u8]>) -> Result<PublicKey, Error> {
+            let pk_p3 = GeP3::from_bytes_vartime(&self.0).ok_or(Error::InvalidPublicKey)?;
+            let mut hx = sha512::Hash::new();
+            hx.update(&blind[..]);
+            hx.update([0u8]);
+            hx.update(ctx.as_ref());
+            let hash_output = hx.finalize();
+            let (blind_factor, _) = KeyPair::split(&hash_output, true, false);
+            let inverse = sc_invert(&blind_factor);
+            Ok(PublicKey(ge_scalarmult(&inverse, &pk_p3).to_bytes()))
+        }
+
+        /// Verifies that the signature `signature` is valid for the message
+        /// `message`.
+        pub fn verify(
+            &self,
+            message: impl AsRef<[u8]>,
+            signature: &Signature,
+        ) -> Result<(), Error> {
+            PublicKey::new(self.0).verify(message, signature)
+        }
+    }
+
+    impl From<PublicKey> for BlindPublicKey {
+        fn from(pk: PublicKey) -> Self {
+            BlindPublicKey(pk.0)
+        }
+    }
+
+    impl From<BlindPublicKey> for PublicKey {
+        fn from(bpk: BlindPublicKey) -> Self {
+            PublicKey(bpk.0)
+        }
+    }
+
+    /// A blind secret key.
+    #[derive(Clone, Debug, Eq, PartialEq, Hash)]
+    pub struct BlindSecretKey {
+        pub prefix: [u8; 2 * Seed::BYTES],
+        pub blind_scalar: [u8; 32],
+        pub blind_pk: BlindPublicKey,
+    }
+
+    #[derive(Clone, Debug, Eq, PartialEq, Hash)]
+    pub struct BlindKeyPair {
+        /// Public key part of the blind key pair.
+        pub blind_pk: BlindPublicKey,
+        /// Secret key part of the blind key pair.
+        pub blind_sk: BlindSecretKey,
+    }
+
+    impl BlindSecretKey {
+        /// Computes a signature for the message `message` using the blind
+        /// secret key. The noise parameter is optional, but recommended
+        /// in order to mitigate fault attacks.
+        pub fn sign(&self, message: impl AsRef<[u8]>, noise: Option<Noise>) -> Signature {
+            let nonce = {
+                let mut hasher = sha512::Hash::new();
+                if let Some(noise) = noise {
+                    hasher.update(&noise[..]);
+                    hasher.update(self.prefix);
+                } else {
+                    hasher.update(self.prefix);
+                }
+                hasher.update(&message);
+                let mut hash_output = hasher.finalize();
+                sc_reduce(&mut hash_output[0..64]);
+                hash_output
+            };
+            let mut signature: [u8; 64] = [0; 64];
+            let r = ge_scalarmult_base(&nonce[0..32]);
+            signature[0..32].copy_from_slice(&r.to_bytes()[..]);
+            signature[32..64].copy_from_slice(&self.blind_pk.0);
+            let mut hasher = sha512::Hash::new();
+            hasher.update(signature.as_ref());
+            hasher.update(&message);
+            let mut hram = hasher.finalize();
+            sc_reduce(&mut hram);
+            sc_muladd(
+                &mut signature[32..64],
+                &hram[0..32],
+                &self.blind_scalar,
+                &nonce[0..32],
+            );
+            let signature = Signature(signature);
+
+            #[cfg(feature = "self-verify")]
+            {
+                PublicKey::from_slice(&self.blind_pk.0)
+                    .expect("Key length changed")
+                    .verify(message, &signature)
+                    .expect("Newly created signature cannot be verified");
+            }
+            signature
+        }
+    }
+
+    impl Drop for BlindSecretKey {
+        fn drop(&mut self) {
+            Mem::wipe(self.prefix);
+            Mem::wipe(self.blind_scalar);
+        }
+    }
+
+    impl PublicKey {
+        /// Returns a blind version of the public key.
+        pub fn blind(&self, blind: &Blind, ctx: impl AsRef<[u8]>) -> Result<BlindPublicKey, Error> {
+            let (blind_factor, _prefix2) = {
+                let mut hx = sha512::Hash::new();
+                hx.update(&blind[..]);
+                hx.update([0u8]);
+                hx.update(ctx.as_ref());
+                let hash_output = hx.finalize();
+                KeyPair::split(&hash_output, true, false)
+            };
+            let pk_p3 = GeP3::from_bytes_vartime(&self.0).ok_or(Error::InvalidPublicKey)?;
+            Ok(BlindPublicKey(
+                ge_scalarmult(&blind_factor, &pk_p3).to_bytes(),
+            ))
+        }
+    }
+
+    impl KeyPair {
+        /// Returns a blind version of the key pair.
+        pub fn blind(&self, blind: &Blind, ctx: impl AsRef<[u8]>) -> BlindKeyPair {
+            let seed = self.sk.seed();
+            let (scalar, prefix1) = {
+                let hash_output = sha512::Hash::hash(&seed[..]);
+                KeyPair::split(&hash_output, false, true)
+            };
+
+            let (blind_factor, prefix2) = {
+                let mut hx = sha512::Hash::new();
+                hx.update(&blind[..]);
+                hx.update([0u8]);
+                hx.update(ctx.as_ref());
+                let hash_output = hx.finalize();
+                KeyPair::split(&hash_output, true, false)
+            };
+
+            let blind_scalar = sc_mul(&scalar, &blind_factor);
+            let blind_pk = ge_scalarmult_base(&blind_scalar).to_bytes();
+
+            let mut prefix = [0u8; 2 * Seed::BYTES];
+            prefix[0..32].copy_from_slice(&prefix1);
+            prefix[32..64].copy_from_slice(&prefix2);
+            let blind_pk = BlindPublicKey::new(blind_pk);
+
+            BlindKeyPair {
+                blind_pk,
+                blind_sk: BlindSecretKey {
+                    prefix,
+                    blind_scalar,
+                    blind_pk,
+                },
+            }
+        }
+    }
+}
+
+#[cfg(feature = "blind-keys")]
+pub use blind_keys::*;
+
+#[test]
+#[cfg(all(feature = "blind-keys", feature = "random"))]
+fn test_blind_ed25519() {
+    use ct_codecs::{Decoder, Hex};
+
+    let kp = KeyPair::generate();
+    let blind = Blind::new([69u8; 32]);
+    let blind_kp = kp.blind(&blind, "ctx");
+    let message = b"Hello, World!";
+    let signature = blind_kp.blind_sk.sign(message, None);
+    assert!(blind_kp.blind_pk.verify(message, &signature).is_ok());
+    let recovered_pk = blind_kp.blind_pk.unblind(&blind, "ctx").unwrap();
+    assert!(recovered_pk == kp.pk);
+
+    let kp = KeyPair::from_seed(
+        Seed::from_slice(
+            &Hex::decode_to_vec(
+                "875532ab039b0a154161c284e19c74afa28d5bf5454e99284bbcffaa71eebf45",
+                None,
+            )
+            .unwrap(),
+        )
+        .unwrap(),
+    );
+    assert_eq!(
+        Hex::decode_to_vec(
+            "3b5983605b277cd44918410eb246bb52d83adfc806ccaa91a60b5b2011bc5973",
+            None
+        )
+        .unwrap(),
+        kp.pk.as_ref()
+    );
+
+    let blind = Blind::from_slice(
+        &Hex::decode_to_vec(
+            "c461e8595f0ac41d374f878613206704978115a226f60470ffd566e9e6ae73bf",
+            None,
+        )
+        .unwrap(),
+    )
+    .unwrap();
+    let blind_kp = kp.blind(&blind, "ctx");
+    assert_eq!(
+        Hex::decode_to_vec(
+            "246dcd43930b81d5e4d770db934a9fcd985b75fd014bc2a98b0aea02311c1836",
+            None
+        )
+        .unwrap(),
+        blind_kp.blind_pk.as_ref()
+    );
+
+    let message = Hex::decode_to_vec("68656c6c6f20776f726c64", None).unwrap();
+    let signature = blind_kp.blind_sk.sign(message, None);
+    assert_eq!(Hex::decode_to_vec("947bacfabc63448f8955dc20630e069e58f37b72bb433ae17f2fa904ea860b44deb761705a3cc2168a6673ee0b41ff7765c7a4896941eec6833c1689315acb0b",
+        None).unwrap(), signature.as_ref());
+}
+
+#[test]
+#[cfg(feature = "random")]
+fn test_streaming() {
+    let kp = KeyPair::generate();
+
+    let msg1 = "mes";
+    let msg2 = "sage";
+    let mut st = kp.sk.sign_incremental(Noise::default());
+    st.absorb(msg1);
+    st.absorb(msg2);
+    let signature = st.sign();
+
+    let msg1 = "mess";
+    let msg2 = "age";
+    let mut st = kp.pk.verify_incremental(&signature).unwrap();
+    st.absorb(msg1);
+    st.absorb(msg2);
+    assert!(st.verify().is_ok());
+}
+
+#[test]
+#[cfg(feature = "random")]
+fn test_ed25519_invalid_keypair() {
+    let kp1 = KeyPair::generate();
+    let kp2 = KeyPair::generate();
+
+    assert_eq!(
+        kp1.sk.validate_public_key(&kp2.pk).unwrap_err(),
+        Error::InvalidPublicKey
+    );
+    assert_eq!(
+        kp2.sk.validate_public_key(&kp1.pk).unwrap_err(),
+        Error::InvalidPublicKey
+    );
+    assert!(kp1.sk.validate_public_key(&kp1.pk).is_ok());
+    assert!(kp2.sk.validate_public_key(&kp2.pk).is_ok());
+    assert!(kp1.validate().is_ok());
+}
diff --git a/vendor/ed25519-compact/src/edwards25519.rs b/vendor/ed25519-compact/src/edwards25519.rs
new file mode 100644
index 0000000..9e51b4c
--- /dev/null
+++ b/vendor/ed25519-compact/src/edwards25519.rs
@@ -0,0 +1,1546 @@
+use core::cmp::min;
+use core::ops::{Add, Sub};
+
+use super::error::*;
+use super::field25519::*;
+
+#[derive(Clone, Copy)]
+pub struct GeP2 {
+    x: Fe,
+    y: Fe,
+    z: Fe,
+}
+
+#[derive(Clone, Copy)]
+pub struct GeP3 {
+    x: Fe,
+    y: Fe,
+    z: Fe,
+    t: Fe,
+}
+
+#[derive(Clone, Copy, Default)]
+pub struct GeP1P1 {
+    x: Fe,
+    y: Fe,
+    z: Fe,
+    t: Fe,
+}
+
+#[derive(Clone, Copy)]
+pub struct GePrecomp {
+    y_plus_x: Fe,
+    y_minus_x: Fe,
+    xy2d: Fe,
+}
+
+#[derive(Clone, Copy, Default)]
+pub struct GeCached {
+    y_plus_x: Fe,
+    y_minus_x: Fe,
+    z: Fe,
+    t2d: Fe,
+}
+
+impl GeCached {
+    pub fn maybe_set(&mut self, other: &GeCached, do_swap: u8) {
+        self.y_plus_x.maybe_set(&other.y_plus_x, do_swap);
+        self.y_minus_x.maybe_set(&other.y_minus_x, do_swap);
+        self.z.maybe_set(&other.z, do_swap);
+        self.t2d.maybe_set(&other.t2d, do_swap);
+    }
+}
+
+impl GeP1P1 {
+    fn to_p2(&self) -> GeP2 {
+        GeP2 {
+            x: self.x * self.t,
+            y: self.y * self.z,
+            z: self.z * self.t,
+        }
+    }
+
+    fn to_p3(&self) -> GeP3 {
+        GeP3 {
+            x: self.x * self.t,
+            y: self.y * self.z,
+            z: self.z * self.t,
+            t: self.x * self.y,
+        }
+    }
+}
+
+impl From<GeP2> for GeP3 {
+    fn from(p: GeP2) -> GeP3 {
+        GeP3 {
+            x: p.x,
+            y: p.y,
+            z: p.z,
+            t: p.x * p.y,
+        }
+    }
+}
+
+impl GeP2 {
+    fn zero() -> GeP2 {
+        GeP2 {
+            x: FE_ZERO,
+            y: FE_ONE,
+            z: FE_ONE,
+        }
+    }
+
+    fn dbl(&self) -> GeP1P1 {
+        let xx = self.x.square();
+        let yy = self.y.square();
+        let b = self.z.square_and_double();
+        let a = self.x + self.y;
+        let aa = a.square();
+        let y3 = yy + xx;
+        let z3 = yy - xx;
+        let x3 = aa - y3;
+        let t3 = b - z3;
+
+        GeP1P1 {
+            x: x3,
+            y: y3,
+            z: z3,
+            t: t3,
+        }
+    }
+
+    fn slide(a: &[u8]) -> [i8; 256] {
+        let mut r = [0i8; 256];
+        for i in 0..256 {
+            r[i] = (1 & (a[i >> 3] >> (i & 7))) as i8;
+        }
+        for i in 0..256 {
+            if r[i] != 0 {
+                for b in 1..min(7, 256 - i) {
+                    if r[i + b] != 0 {
+                        if r[i] + (r[i + b] << b) <= 15 {
+                            r[i] += r[i + b] << b;
+                            r[i + b] = 0;
+                        } else if r[i] - (r[i + b] << b) >= -15 {
+                            r[i] -= r[i + b] << b;
+                            for k in i + b..256 {
+                                if r[k] == 0 {
+                                    r[k] = 1;
+                                    break;
+                                }
+                                r[k] = 0;
+                            }
+                        } else {
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+
+        r
+    }
+
+    #[allow(clippy::comparison_chain)]
+    pub fn double_scalarmult_vartime(a_scalar: &[u8], a_point: GeP3, b_scalar: &[u8]) -> GeP2 {
+        let aslide = GeP2::slide(a_scalar);
+        let bslide = GeP2::slide(b_scalar);
+
+        let mut ai = [GeCached {
+            y_plus_x: FE_ZERO,
+            y_minus_x: FE_ZERO,
+            z: FE_ZERO,
+            t2d: FE_ZERO,
+        }; 8]; // A,3A,5A,7A,9A,11A,13A,15A
+        ai[0] = a_point.to_cached();
+        let a2 = a_point.dbl().to_p3();
+        ai[1] = (a2 + ai[0]).to_p3().to_cached();
+        ai[2] = (a2 + ai[1]).to_p3().to_cached();
+        ai[3] = (a2 + ai[2]).to_p3().to_cached();
+        ai[4] = (a2 + ai[3]).to_p3().to_cached();
+        ai[5] = (a2 + ai[4]).to_p3().to_cached();
+        ai[6] = (a2 + ai[5]).to_p3().to_cached();
+        ai[7] = (a2 + ai[6]).to_p3().to_cached();
+
+        let mut r = GeP2::zero();
+
+        let mut i: usize = 255;
+        loop {
+            if aslide[i] != 0 || bslide[i] != 0 {
+                break;
+            }
+            if i == 0 {
+                return r;
+            }
+            i -= 1;
+        }
+
+        loop {
+            let mut t = r.dbl();
+            if aslide[i] > 0 {
+                t = t.to_p3() + ai[(aslide[i] / 2) as usize];
+            } else if aslide[i] < 0 {
+                t = t.to_p3() - ai[(-aslide[i] / 2) as usize];
+            }
+
+            if bslide[i] > 0 {
+                t = t.to_p3() + BI[(bslide[i] / 2) as usize];
+            } else if bslide[i] < 0 {
+                t = t.to_p3() - BI[(-bslide[i] / 2) as usize];
+            }
+
+            r = t.to_p2();
+
+            if i == 0 {
+                return r;
+            }
+            i -= 1;
+        }
+    }
+}
+
+impl GeP3 {
+    pub fn from_bytes_negate_vartime(s: &[u8; 32]) -> Option<GeP3> {
+        let y = Fe::from_bytes(s);
+        let z = FE_ONE;
+        let y_squared = y.square();
+        let u = y_squared - FE_ONE;
+        let v = (y_squared * FE_D) + FE_ONE;
+        let mut x = (u * v).pow25523() * u;
+
+        let vxx = x.square() * v;
+        let check = vxx - u;
+        if !check.is_zero() {
+            let check2 = vxx + u;
+            if !check2.is_zero() {
+                return None;
+            }
+            x = x * FE_SQRTM1;
+        }
+
+        if x.is_negative() == ((s[31] >> 7) != 0) {
+            x = x.neg();
+        }
+
+        let t = x * y;
+
+        Some(GeP3 { x, y, z, t })
+    }
+
+    pub fn from_bytes_vartime(s: &[u8; 32]) -> Option<GeP3> {
+        Self::from_bytes_negate_vartime(s).map(|p| GeP3 {
+            x: p.x.neg(),
+            y: p.y,
+            z: p.z,
+            t: p.t.neg(),
+        })
+    }
+
+    fn to_p2(&self) -> GeP2 {
+        GeP2 {
+            x: self.x,
+            y: self.y,
+            z: self.z,
+        }
+    }
+
+    fn to_cached(&self) -> GeCached {
+        GeCached {
+            y_plus_x: self.y + self.x,
+            y_minus_x: self.y - self.x,
+            z: self.z,
+            t2d: self.t * FE_D2,
+        }
+    }
+
+    fn zero() -> GeP3 {
+        GeP3 {
+            x: FE_ZERO,
+            y: FE_ONE,
+            z: FE_ONE,
+            t: FE_ZERO,
+        }
+    }
+
+    fn dbl(&self) -> GeP1P1 {
+        self.to_p2().dbl()
+    }
+
+    pub fn to_bytes(&self) -> [u8; 32] {
+        let recip = self.z.invert();
+        let x = self.x * recip;
+        let y = self.y * recip;
+        let mut bs = y.to_bytes();
+        bs[31] ^= (if x.is_negative() { 1 } else { 0 }) << 7;
+        bs
+    }
+
+    pub fn has_small_order(&self) -> bool {
+        let recip = self.z.invert();
+        let x = self.x * recip;
+        let y = self.y * recip;
+        let x_neg = x.neg();
+        let y_sqrtm1 = y * FE_SQRTM1;
+        x.is_zero() | y.is_zero() | (y_sqrtm1 == x) | (y_sqrtm1 == x_neg)
+    }
+}
+
+impl Add<GeP3> for GeP3 {
+    type Output = GeP3;
+
+    fn add(self, other: GeP3) -> GeP3 {
+        (self + other.to_cached()).to_p3()
+    }
+}
+
+impl Sub<GeP3> for GeP3 {
+    type Output = GeP3;
+
+    fn sub(self, other: GeP3) -> GeP3 {
+        (self - other.to_cached()).to_p3()
+    }
+}
+
+impl Add<GeCached> for GeP3 {
+    type Output = GeP1P1;
+
+    fn add(self, _rhs: GeCached) -> GeP1P1 {
+        let y1_plus_x1 = self.y + self.x;
+        let y1_minus_x1 = self.y - self.x;
+        let a = y1_plus_x1 * _rhs.y_plus_x;
+        let b = y1_minus_x1 * _rhs.y_minus_x;
+        let c = _rhs.t2d * self.t;
+        let zz = self.z * _rhs.z;
+        let d = zz + zz;
+        let x3 = a - b;
+        let y3 = a + b;
+        let z3 = d + c;
+        let t3 = d - c;
+
+        GeP1P1 {
+            x: x3,
+            y: y3,
+            z: z3,
+            t: t3,
+        }
+    }
+}
+
+impl Add<GePrecomp> for GeP3 {
+    type Output = GeP1P1;
+
+    fn add(self, _rhs: GePrecomp) -> GeP1P1 {
+        let y1_plus_x1 = self.y + self.x;
+        let y1_minus_x1 = self.y - self.x;
+        let a = y1_plus_x1 * _rhs.y_plus_x;
+        let b = y1_minus_x1 * _rhs.y_minus_x;
+        let c = _rhs.xy2d * self.t;
+        let d = self.z + self.z;
+        let x3 = a - b;
+        let y3 = a + b;
+        let z3 = d + c;
+        let t3 = d - c;
+
+        GeP1P1 {
+            x: x3,
+            y: y3,
+            z: z3,
+            t: t3,
+        }
+    }
+}
+
+impl Sub<GeCached> for GeP3 {
+    type Output = GeP1P1;
+
+    fn sub(self, _rhs: GeCached) -> GeP1P1 {
+        let y1_plus_x1 = self.y + self.x;
+        let y1_minus_x1 = self.y - self.x;
+        let a = y1_plus_x1 * _rhs.y_minus_x;
+        let b = y1_minus_x1 * _rhs.y_plus_x;
+        let c = _rhs.t2d * self.t;
+        let zz = self.z * _rhs.z;
+        let d = zz + zz;
+        let x3 = a - b;
+        let y3 = a + b;
+        let z3 = d - c;
+        let t3 = d + c;
+
+        GeP1P1 {
+            x: x3,
+            y: y3,
+            z: z3,
+            t: t3,
+        }
+    }
+}
+
+impl Sub<GePrecomp> for GeP3 {
+    type Output = GeP1P1;
+
+    fn sub(self, _rhs: GePrecomp) -> GeP1P1 {
+        let y1_plus_x1 = self.y + self.x;
+        let y1_minus_x1 = self.y - self.x;
+        let a = y1_plus_x1 * _rhs.y_minus_x;
+        let b = y1_minus_x1 * _rhs.y_plus_x;
+        let c = _rhs.xy2d * self.t;
+        let d = self.z + self.z;
+        let x3 = a - b;
+        let y3 = a + b;
+        let z3 = d - c;
+        let t3 = d + c;
+
+        GeP1P1 {
+            x: x3,
+            y: y3,
+            z: z3,
+            t: t3,
+        }
+    }
+}
+
+fn ge_precompute(base: &GeP3) -> [GeCached; 16] {
+    let base_cached = base.to_cached();
+    let mut pc = [GeP3::zero(); 16];
+    pc[1] = *base;
+    for i in 2..16 {
+        pc[i] = if i % 2 == 0 {
+            pc[i / 2].dbl().to_p3()
+        } else {
+            pc[(i - 1)].add(base_cached).to_p3()
+        }
+    }
+    let mut pc_cached: [GeCached; 16] = Default::default();
+    for i in 0..16 {
+        pc_cached[i] = pc[i].to_cached();
+    }
+    pc_cached
+}
+
+pub fn ge_scalarmult(scalar: &[u8], base: &GeP3) -> GeP3 {
+    let pc = ge_precompute(base);
+    let mut q = GeP3::zero();
+    let mut pos = 252;
+    loop {
+        let slot = ((scalar[pos >> 3] >> (pos & 7)) & 15) as usize;
+        let mut t = pc[0];
+        for i in 1..16 {
+            t.maybe_set(&pc[i], (((slot ^ i).wrapping_sub(1)) >> 8) as u8 & 1);
+        }
+        q = q.add(t).to_p3();
+        if pos == 0 {
+            break;
+        }
+        q = q.dbl().to_p3().dbl().to_p3().dbl().to_p3().dbl().to_p3();
+        pos -= 4;
+    }
+    q
+}
+
+pub fn ge_scalarmult_base(scalar: &[u8]) -> GeP3 {
+    const BXP: [u8; 32] = [
+        0x1a, 0xd5, 0x25, 0x8f, 0x60, 0x2d, 0x56, 0xc9, 0xb2, 0xa7, 0x25, 0x95, 0x60, 0xc7, 0x2c,
+        0x69, 0x5c, 0xdc, 0xd6, 0xfd, 0x31, 0xe2, 0xa4, 0xc0, 0xfe, 0x53, 0x6e, 0xcd, 0xd3, 0x36,
+        0x69, 0x21,
+    ];
+    const BYP: [u8; 32] = [
+        0x58, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66,
+        0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x66,
+        0x66, 0x66,
+    ];
+    let bx = Fe::from_bytes(&BXP);
+    let by = Fe::from_bytes(&BYP);
+    let base = GeP3 {
+        x: bx,
+        y: by,
+        z: FE_ONE,
+        t: bx * by,
+    };
+    ge_scalarmult(scalar, &base)
+}
+
+#[cfg(feature = "x25519")]
+pub fn ge_to_x25519_vartime(s: &[u8; 32]) -> Option<[u8; 32]> {
+    let p = GeP3::from_bytes_vartime(s)?;
+    let yed = p.y;
+    let x_mont = (FE_ONE + yed) * ((FE_ONE - yed).invert());
+    Some(x_mont.to_bytes())
+}
+
+pub fn sc_reduce32(s: &mut [u8; 32]) {
+    let mut t = [0u8; 64];
+    t[0..32].copy_from_slice(s);
+    sc_reduce(&mut t);
+    s.copy_from_slice(&t[0..32]);
+}
+
+pub fn sc_reduce(s: &mut [u8]) {
+    let mut s0: i64 = 2097151 & load_3i(s);
+    let mut s1: i64 = 2097151 & (load_4i(&s[2..6]) >> 5);
+    let mut s2: i64 = 2097151 & (load_3i(&s[5..8]) >> 2);
+    let mut s3: i64 = 2097151 & (load_4i(&s[7..11]) >> 7);
+    let mut s4: i64 = 2097151 & (load_4i(&s[10..14]) >> 4);
+    let mut s5: i64 = 2097151 & (load_3i(&s[13..16]) >> 1);
+    let mut s6: i64 = 2097151 & (load_4i(&s[15..19]) >> 6);
+    let mut s7: i64 = 2097151 & (load_3i(&s[18..21]) >> 3);
+    let mut s8: i64 = 2097151 & load_3i(&s[21..24]);
+    let mut s9: i64 = 2097151 & (load_4i(&s[23..27]) >> 5);
+    let mut s10: i64 = 2097151 & (load_3i(&s[26..29]) >> 2);
+    let mut s11: i64 = 2097151 & (load_4i(&s[28..32]) >> 7);
+    let mut s12: i64 = 2097151 & (load_4i(&s[31..35]) >> 4);
+    let mut s13: i64 = 2097151 & (load_3i(&s[34..37]) >> 1);
+    let mut s14: i64 = 2097151 & (load_4i(&s[36..40]) >> 6);
+    let mut s15: i64 = 2097151 & (load_3i(&s[39..42]) >> 3);
+    let mut s16: i64 = 2097151 & load_3i(&s[42..45]);
+    let mut s17: i64 = 2097151 & (load_4i(&s[44..48]) >> 5);
+    let s18: i64 = 2097151 & (load_3i(&s[47..50]) >> 2);
+    let s19: i64 = 2097151 & (load_4i(&s[49..53]) >> 7);
+    let s20: i64 = 2097151 & (load_4i(&s[52..56]) >> 4);
+    let s21: i64 = 2097151 & (load_3i(&s[55..58]) >> 1);
+    let s22: i64 = 2097151 & (load_4i(&s[57..61]) >> 6);
+    let s23: i64 = load_4i(&s[60..64]) >> 3;
+
+    s11 += s23 * 666643;
+    s12 += s23 * 470296;
+    s13 += s23 * 654183;
+    s14 -= s23 * 997805;
+    s15 += s23 * 136657;
+    s16 -= s23 * 683901;
+
+    s10 += s22 * 666643;
+    s11 += s22 * 470296;
+    s12 += s22 * 654183;
+    s13 -= s22 * 997805;
+    s14 += s22 * 136657;
+    s15 -= s22 * 683901;
+
+    s9 += s21 * 666643;
+    s10 += s21 * 470296;
+    s11 += s21 * 654183;
+    s12 -= s21 * 997805;
+    s13 += s21 * 136657;
+    s14 -= s21 * 683901;
+
+    s8 += s20 * 666643;
+    s9 += s20 * 470296;
+    s10 += s20 * 654183;
+    s11 -= s20 * 997805;
+    s12 += s20 * 136657;
+    s13 -= s20 * 683901;
+
+    s7 += s19 * 666643;
+    s8 += s19 * 470296;
+    s9 += s19 * 654183;
+    s10 -= s19 * 997805;
+    s11 += s19 * 136657;
+    s12 -= s19 * 683901;
+
+    s6 += s18 * 666643;
+    s7 += s18 * 470296;
+    s8 += s18 * 654183;
+    s9 -= s18 * 997805;
+    s10 += s18 * 136657;
+    s11 -= s18 * 683901;
+
+    let mut carry6: i64 = (s6 + (1 << 20)) >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    let mut carry8: i64 = (s8 + (1 << 20)) >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    let mut carry10: i64 = (s10 + (1 << 20)) >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+    let carry12: i64 = (s12 + (1 << 20)) >> 21;
+    s13 += carry12;
+    s12 -= carry12 << 21;
+    let carry14: i64 = (s14 + (1 << 20)) >> 21;
+    s15 += carry14;
+    s14 -= carry14 << 21;
+    let carry16: i64 = (s16 + (1 << 20)) >> 21;
+    s17 += carry16;
+    s16 -= carry16 << 21;
+
+    let mut carry7: i64 = (s7 + (1 << 20)) >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    let mut carry9: i64 = (s9 + (1 << 20)) >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    let mut carry11: i64 = (s11 + (1 << 20)) >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+    let carry13: i64 = (s13 + (1 << 20)) >> 21;
+    s14 += carry13;
+    s13 -= carry13 << 21;
+    let carry15: i64 = (s15 + (1 << 20)) >> 21;
+    s16 += carry15;
+    s15 -= carry15 << 21;
+
+    s5 += s17 * 666643;
+    s6 += s17 * 470296;
+    s7 += s17 * 654183;
+    s8 -= s17 * 997805;
+    s9 += s17 * 136657;
+    s10 -= s17 * 683901;
+
+    s4 += s16 * 666643;
+    s5 += s16 * 470296;
+    s6 += s16 * 654183;
+    s7 -= s16 * 997805;
+    s8 += s16 * 136657;
+    s9 -= s16 * 683901;
+
+    s3 += s15 * 666643;
+    s4 += s15 * 470296;
+    s5 += s15 * 654183;
+    s6 -= s15 * 997805;
+    s7 += s15 * 136657;
+    s8 -= s15 * 683901;
+
+    s2 += s14 * 666643;
+    s3 += s14 * 470296;
+    s4 += s14 * 654183;
+    s5 -= s14 * 997805;
+    s6 += s14 * 136657;
+    s7 -= s14 * 683901;
+
+    s1 += s13 * 666643;
+    s2 += s13 * 470296;
+    s3 += s13 * 654183;
+    s4 -= s13 * 997805;
+    s5 += s13 * 136657;
+    s6 -= s13 * 683901;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+    s12 = 0;
+
+    let mut carry0: i64 = (s0 + (1 << 20)) >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    let mut carry2: i64 = (s2 + (1 << 20)) >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    let mut carry4: i64 = (s4 + (1 << 20)) >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry6 = (s6 + (1 << 20)) >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry8 = (s8 + (1 << 20)) >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry10 = (s10 + (1 << 20)) >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+
+    let mut carry1: i64 = (s1 + (1 << 20)) >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    let mut carry3: i64 = (s3 + (1 << 20)) >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    let mut carry5: i64 = (s5 + (1 << 20)) >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry7 = (s7 + (1 << 20)) >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry9 = (s9 + (1 << 20)) >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry11 = (s11 + (1 << 20)) >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+    s12 = 0;
+
+    carry0 = s0 >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    carry1 = s1 >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    carry2 = s2 >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    carry3 = s3 >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    carry4 = s4 >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry5 = s5 >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry6 = s6 >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry7 = s7 >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry8 = s8 >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry9 = s9 >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry10 = s10 >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+    carry11 = s11 >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+
+    carry0 = s0 >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    carry1 = s1 >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    carry2 = s2 >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    carry3 = s3 >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    carry4 = s4 >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry5 = s5 >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry6 = s6 >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry7 = s7 >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry8 = s8 >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry9 = s9 >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry10 = s10 >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+
+    s[0] = (s0 >> 0) as u8;
+    s[1] = (s0 >> 8) as u8;
+    s[2] = ((s0 >> 16) | (s1 << 5)) as u8;
+    s[3] = (s1 >> 3) as u8;
+    s[4] = (s1 >> 11) as u8;
+    s[5] = ((s1 >> 19) | (s2 << 2)) as u8;
+    s[6] = (s2 >> 6) as u8;
+    s[7] = ((s2 >> 14) | (s3 << 7)) as u8;
+    s[8] = (s3 >> 1) as u8;
+    s[9] = (s3 >> 9) as u8;
+    s[10] = ((s3 >> 17) | (s4 << 4)) as u8;
+    s[11] = (s4 >> 4) as u8;
+    s[12] = (s4 >> 12) as u8;
+    s[13] = ((s4 >> 20) | (s5 << 1)) as u8;
+    s[14] = (s5 >> 7) as u8;
+    s[15] = ((s5 >> 15) | (s6 << 6)) as u8;
+    s[16] = (s6 >> 2) as u8;
+    s[17] = (s6 >> 10) as u8;
+    s[18] = ((s6 >> 18) | (s7 << 3)) as u8;
+    s[19] = (s7 >> 5) as u8;
+    s[20] = (s7 >> 13) as u8;
+    s[21] = (s8 >> 0) as u8;
+    s[22] = (s8 >> 8) as u8;
+    s[23] = ((s8 >> 16) | (s9 << 5)) as u8;
+    s[24] = (s9 >> 3) as u8;
+    s[25] = (s9 >> 11) as u8;
+    s[26] = ((s9 >> 19) | (s10 << 2)) as u8;
+    s[27] = (s10 >> 6) as u8;
+    s[28] = ((s10 >> 14) | (s11 << 7)) as u8;
+    s[29] = (s11 >> 1) as u8;
+    s[30] = (s11 >> 9) as u8;
+    s[31] = (s11 >> 17) as u8;
+}
+
+#[cfg(feature = "blind-keys")]
+pub fn sc_mul(a: &[u8], b: &[u8]) -> [u8; 32] {
+    let mut s = [0u8; 32];
+    sc_muladd(&mut s, a, b, &[0; 32]);
+    s
+}
+
+#[cfg(feature = "blind-keys")]
+pub fn sc_sq(s: &[u8]) -> [u8; 32] {
+    sc_mul(s, s)
+}
+
+#[cfg(feature = "blind-keys")]
+pub fn sc_sqmul(s: &[u8], n: usize, a: &[u8]) -> [u8; 32] {
+    let mut t = [0u8; 32];
+    t.copy_from_slice(s);
+    for _ in 0..n {
+        t = sc_sq(&t);
+    }
+    sc_mul(&t, a)
+}
+
+#[cfg(feature = "blind-keys")]
+pub fn sc_invert(s: &[u8; 32]) -> [u8; 32] {
+    let _10 = sc_sq(s);
+    let _11 = sc_mul(s, &_10);
+    let _100 = sc_mul(s, &_11);
+    let _1000 = sc_sq(&_100);
+    let _1010 = sc_mul(&_10, &_1000);
+    let _1011 = sc_mul(s, &_1010);
+    let _10000 = sc_sq(&_1000);
+    let _10110 = sc_sq(&_1011);
+    let _100000 = sc_mul(&_1010, &_10110);
+    let _100110 = sc_mul(&_10000, &_10110);
+    let _1000000 = sc_sq(&_100000);
+    let _1010000 = sc_mul(&_10000, &_1000000);
+    let _1010011 = sc_mul(&_11, &_1010000);
+    let _1100011 = sc_mul(&_10000, &_1010011);
+    let _1100111 = sc_mul(&_100, &_1100011);
+    let _1101011 = sc_mul(&_100, &_1100111);
+    let _10010011 = sc_mul(&_1000000, &_1010011);
+    let _10010111 = sc_mul(&_100, &_10010011);
+    let _10111101 = sc_mul(&_100110, &_10010111);
+    let _11010011 = sc_mul(&_10110, &_10111101);
+    let _11100111 = sc_mul(&_1010000, &_10010111);
+    let _11101011 = sc_mul(&_100, &_11100111);
+    let _11110101 = sc_mul(&_1010, &_11101011);
+
+    let mut recip = sc_mul(&_1011, &_11110101);
+    recip = sc_sqmul(&recip, 126, &_1010011);
+    recip = sc_sqmul(&recip, 9, &_10);
+    recip = sc_mul(&recip, &_11110101);
+    recip = sc_sqmul(&recip, 7, &_1100111);
+    recip = sc_sqmul(&recip, 9, &_11110101);
+    recip = sc_sqmul(&recip, 11, &_10111101);
+    recip = sc_sqmul(&recip, 8, &_11100111);
+    recip = sc_sqmul(&recip, 9, &_1101011);
+    recip = sc_sqmul(&recip, 6, &_1011);
+    recip = sc_sqmul(&recip, 14, &_10010011);
+    recip = sc_sqmul(&recip, 10, &_1100011);
+    recip = sc_sqmul(&recip, 9, &_10010111);
+    recip = sc_sqmul(&recip, 10, &_11110101);
+    recip = sc_sqmul(&recip, 8, &_11010011);
+    recip = sc_sqmul(&recip, 8, &_11101011);
+    recip
+}
+
+pub fn sc_muladd(s: &mut [u8], a: &[u8], b: &[u8], c: &[u8]) {
+    let a0 = 2097151 & load_3i(&a[0..3]);
+    let a1 = 2097151 & (load_4i(&a[2..6]) >> 5);
+    let a2 = 2097151 & (load_3i(&a[5..8]) >> 2);
+    let a3 = 2097151 & (load_4i(&a[7..11]) >> 7);
+    let a4 = 2097151 & (load_4i(&a[10..14]) >> 4);
+    let a5 = 2097151 & (load_3i(&a[13..16]) >> 1);
+    let a6 = 2097151 & (load_4i(&a[15..19]) >> 6);
+    let a7 = 2097151 & (load_3i(&a[18..21]) >> 3);
+    let a8 = 2097151 & load_3i(&a[21..24]);
+    let a9 = 2097151 & (load_4i(&a[23..27]) >> 5);
+    let a10 = 2097151 & (load_3i(&a[26..29]) >> 2);
+    let a11 = load_4i(&a[28..32]) >> 7;
+    let b0 = 2097151 & load_3i(&b[0..3]);
+    let b1 = 2097151 & (load_4i(&b[2..6]) >> 5);
+    let b2 = 2097151 & (load_3i(&b[5..8]) >> 2);
+    let b3 = 2097151 & (load_4i(&b[7..11]) >> 7);
+    let b4 = 2097151 & (load_4i(&b[10..14]) >> 4);
+    let b5 = 2097151 & (load_3i(&b[13..16]) >> 1);
+    let b6 = 2097151 & (load_4i(&b[15..19]) >> 6);
+    let b7 = 2097151 & (load_3i(&b[18..21]) >> 3);
+    let b8 = 2097151 & load_3i(&b[21..24]);
+    let b9 = 2097151 & (load_4i(&b[23..27]) >> 5);
+    let b10 = 2097151 & (load_3i(&b[26..29]) >> 2);
+    let b11 = load_4i(&b[28..32]) >> 7;
+    let c0 = 2097151 & load_3i(&c[0..3]);
+    let c1 = 2097151 & (load_4i(&c[2..6]) >> 5);
+    let c2 = 2097151 & (load_3i(&c[5..8]) >> 2);
+    let c3 = 2097151 & (load_4i(&c[7..11]) >> 7);
+    let c4 = 2097151 & (load_4i(&c[10..14]) >> 4);
+    let c5 = 2097151 & (load_3i(&c[13..16]) >> 1);
+    let c6 = 2097151 & (load_4i(&c[15..19]) >> 6);
+    let c7 = 2097151 & (load_3i(&c[18..21]) >> 3);
+    let c8 = 2097151 & load_3i(&c[21..24]);
+    let c9 = 2097151 & (load_4i(&c[23..27]) >> 5);
+    let c10 = 2097151 & (load_3i(&c[26..29]) >> 2);
+    let c11 = load_4i(&c[28..32]) >> 7;
+
+    let mut s0: i64 = c0 + a0 * b0;
+    let mut s1: i64 = c1 + a0 * b1 + a1 * b0;
+    let mut s2: i64 = c2 + a0 * b2 + a1 * b1 + a2 * b0;
+    let mut s3: i64 = c3 + a0 * b3 + a1 * b2 + a2 * b1 + a3 * b0;
+    let mut s4: i64 = c4 + a0 * b4 + a1 * b3 + a2 * b2 + a3 * b1 + a4 * b0;
+    let mut s5: i64 = c5 + a0 * b5 + a1 * b4 + a2 * b3 + a3 * b2 + a4 * b1 + a5 * b0;
+    let mut s6: i64 = c6 + a0 * b6 + a1 * b5 + a2 * b4 + a3 * b3 + a4 * b2 + a5 * b1 + a6 * b0;
+    let mut s7: i64 =
+        c7 + a0 * b7 + a1 * b6 + a2 * b5 + a3 * b4 + a4 * b3 + a5 * b2 + a6 * b1 + a7 * b0;
+    let mut s8: i64 = c8
+        + a0 * b8
+        + a1 * b7
+        + a2 * b6
+        + a3 * b5
+        + a4 * b4
+        + a5 * b3
+        + a6 * b2
+        + a7 * b1
+        + a8 * b0;
+    let mut s9: i64 = c9
+        + a0 * b9
+        + a1 * b8
+        + a2 * b7
+        + a3 * b6
+        + a4 * b5
+        + a5 * b4
+        + a6 * b3
+        + a7 * b2
+        + a8 * b1
+        + a9 * b0;
+    let mut s10: i64 = c10
+        + a0 * b10
+        + a1 * b9
+        + a2 * b8
+        + a3 * b7
+        + a4 * b6
+        + a5 * b5
+        + a6 * b4
+        + a7 * b3
+        + a8 * b2
+        + a9 * b1
+        + a10 * b0;
+    let mut s11: i64 = c11
+        + a0 * b11
+        + a1 * b10
+        + a2 * b9
+        + a3 * b8
+        + a4 * b7
+        + a5 * b6
+        + a6 * b5
+        + a7 * b4
+        + a8 * b3
+        + a9 * b2
+        + a10 * b1
+        + a11 * b0;
+    let mut s12: i64 = a1 * b11
+        + a2 * b10
+        + a3 * b9
+        + a4 * b8
+        + a5 * b7
+        + a6 * b6
+        + a7 * b5
+        + a8 * b4
+        + a9 * b3
+        + a10 * b2
+        + a11 * b1;
+    let mut s13: i64 = a2 * b11
+        + a3 * b10
+        + a4 * b9
+        + a5 * b8
+        + a6 * b7
+        + a7 * b6
+        + a8 * b5
+        + a9 * b4
+        + a10 * b3
+        + a11 * b2;
+    let mut s14: i64 =
+        a3 * b11 + a4 * b10 + a5 * b9 + a6 * b8 + a7 * b7 + a8 * b6 + a9 * b5 + a10 * b4 + a11 * b3;
+    let mut s15: i64 =
+        a4 * b11 + a5 * b10 + a6 * b9 + a7 * b8 + a8 * b7 + a9 * b6 + a10 * b5 + a11 * b4;
+    let mut s16: i64 = a5 * b11 + a6 * b10 + a7 * b9 + a8 * b8 + a9 * b7 + a10 * b6 + a11 * b5;
+    let mut s17: i64 = a6 * b11 + a7 * b10 + a8 * b9 + a9 * b8 + a10 * b7 + a11 * b6;
+    let mut s18: i64 = a7 * b11 + a8 * b10 + a9 * b9 + a10 * b8 + a11 * b7;
+    let mut s19: i64 = a8 * b11 + a9 * b10 + a10 * b9 + a11 * b8;
+    let mut s20: i64 = a9 * b11 + a10 * b10 + a11 * b9;
+    let mut s21: i64 = a10 * b11 + a11 * b10;
+    let mut s22: i64 = a11 * b11;
+    let mut s23: i64 = 0;
+
+    let mut carry0: i64 = (s0 + (1 << 20)) >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    let mut carry2: i64 = (s2 + (1 << 20)) >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    let mut carry4: i64 = (s4 + (1 << 20)) >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    let mut carry6: i64 = (s6 + (1 << 20)) >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    let mut carry8: i64 = (s8 + (1 << 20)) >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    let mut carry10: i64 = (s10 + (1 << 20)) >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+    let mut carry12: i64 = (s12 + (1 << 20)) >> 21;
+    s13 += carry12;
+    s12 -= carry12 << 21;
+    let mut carry14: i64 = (s14 + (1 << 20)) >> 21;
+    s15 += carry14;
+    s14 -= carry14 << 21;
+    let mut carry16: i64 = (s16 + (1 << 20)) >> 21;
+    s17 += carry16;
+    s16 -= carry16 << 21;
+    let carry18: i64 = (s18 + (1 << 20)) >> 21;
+    s19 += carry18;
+    s18 -= carry18 << 21;
+    let carry20: i64 = (s20 + (1 << 20)) >> 21;
+    s21 += carry20;
+    s20 -= carry20 << 21;
+    let carry22: i64 = (s22 + (1 << 20)) >> 21;
+    s23 += carry22;
+    s22 -= carry22 << 21;
+
+    let mut carry1: i64 = (s1 + (1 << 20)) >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    let mut carry3: i64 = (s3 + (1 << 20)) >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    let mut carry5: i64 = (s5 + (1 << 20)) >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    let mut carry7: i64 = (s7 + (1 << 20)) >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    let mut carry9: i64 = (s9 + (1 << 20)) >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    let mut carry11: i64 = (s11 + (1 << 20)) >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+    let mut carry13: i64 = (s13 + (1 << 20)) >> 21;
+    s14 += carry13;
+    s13 -= carry13 << 21;
+    let mut carry15: i64 = (s15 + (1 << 20)) >> 21;
+    s16 += carry15;
+    s15 -= carry15 << 21;
+    let carry17: i64 = (s17 + (1 << 20)) >> 21;
+    s18 += carry17;
+    s17 -= carry17 << 21;
+    let carry19: i64 = (s19 + (1 << 20)) >> 21;
+    s20 += carry19;
+    s19 -= carry19 << 21;
+    let carry21: i64 = (s21 + (1 << 20)) >> 21;
+    s22 += carry21;
+    s21 -= carry21 << 21;
+
+    s11 += s23 * 666643;
+    s12 += s23 * 470296;
+    s13 += s23 * 654183;
+    s14 -= s23 * 997805;
+    s15 += s23 * 136657;
+    s16 -= s23 * 683901;
+
+    s10 += s22 * 666643;
+    s11 += s22 * 470296;
+    s12 += s22 * 654183;
+    s13 -= s22 * 997805;
+    s14 += s22 * 136657;
+    s15 -= s22 * 683901;
+
+    s9 += s21 * 666643;
+    s10 += s21 * 470296;
+    s11 += s21 * 654183;
+    s12 -= s21 * 997805;
+    s13 += s21 * 136657;
+    s14 -= s21 * 683901;
+
+    s8 += s20 * 666643;
+    s9 += s20 * 470296;
+    s10 += s20 * 654183;
+    s11 -= s20 * 997805;
+    s12 += s20 * 136657;
+    s13 -= s20 * 683901;
+
+    s7 += s19 * 666643;
+    s8 += s19 * 470296;
+    s9 += s19 * 654183;
+    s10 -= s19 * 997805;
+    s11 += s19 * 136657;
+    s12 -= s19 * 683901;
+
+    s6 += s18 * 666643;
+    s7 += s18 * 470296;
+    s8 += s18 * 654183;
+    s9 -= s18 * 997805;
+    s10 += s18 * 136657;
+    s11 -= s18 * 683901;
+
+    carry6 = (s6 + (1 << 20)) >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry8 = (s8 + (1 << 20)) >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry10 = (s10 + (1 << 20)) >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+    carry12 = (s12 + (1 << 20)) >> 21;
+    s13 += carry12;
+    s12 -= carry12 << 21;
+    carry14 = (s14 + (1 << 20)) >> 21;
+    s15 += carry14;
+    s14 -= carry14 << 21;
+    carry16 = (s16 + (1 << 20)) >> 21;
+    s17 += carry16;
+    s16 -= carry16 << 21;
+
+    carry7 = (s7 + (1 << 20)) >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry9 = (s9 + (1 << 20)) >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry11 = (s11 + (1 << 20)) >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+    carry13 = (s13 + (1 << 20)) >> 21;
+    s14 += carry13;
+    s13 -= carry13 << 21;
+    carry15 = (s15 + (1 << 20)) >> 21;
+    s16 += carry15;
+    s15 -= carry15 << 21;
+
+    s5 += s17 * 666643;
+    s6 += s17 * 470296;
+    s7 += s17 * 654183;
+    s8 -= s17 * 997805;
+    s9 += s17 * 136657;
+    s10 -= s17 * 683901;
+
+    s4 += s16 * 666643;
+    s5 += s16 * 470296;
+    s6 += s16 * 654183;
+    s7 -= s16 * 997805;
+    s8 += s16 * 136657;
+    s9 -= s16 * 683901;
+
+    s3 += s15 * 666643;
+    s4 += s15 * 470296;
+    s5 += s15 * 654183;
+    s6 -= s15 * 997805;
+    s7 += s15 * 136657;
+    s8 -= s15 * 683901;
+
+    s2 += s14 * 666643;
+    s3 += s14 * 470296;
+    s4 += s14 * 654183;
+    s5 -= s14 * 997805;
+    s6 += s14 * 136657;
+    s7 -= s14 * 683901;
+
+    s1 += s13 * 666643;
+    s2 += s13 * 470296;
+    s3 += s13 * 654183;
+    s4 -= s13 * 997805;
+    s5 += s13 * 136657;
+    s6 -= s13 * 683901;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+    s12 = 0;
+
+    carry0 = (s0 + (1 << 20)) >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    carry2 = (s2 + (1 << 20)) >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    carry4 = (s4 + (1 << 20)) >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry6 = (s6 + (1 << 20)) >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry8 = (s8 + (1 << 20)) >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry10 = (s10 + (1 << 20)) >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+
+    carry1 = (s1 + (1 << 20)) >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    carry3 = (s3 + (1 << 20)) >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    carry5 = (s5 + (1 << 20)) >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry7 = (s7 + (1 << 20)) >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry9 = (s9 + (1 << 20)) >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry11 = (s11 + (1 << 20)) >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+    s12 = 0;
+
+    carry0 = s0 >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    carry1 = s1 >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    carry2 = s2 >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    carry3 = s3 >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    carry4 = s4 >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry5 = s5 >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry6 = s6 >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry7 = s7 >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry8 = s8 >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry9 = s9 >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry10 = s10 >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+    carry11 = s11 >> 21;
+    s12 += carry11;
+    s11 -= carry11 << 21;
+
+    s0 += s12 * 666643;
+    s1 += s12 * 470296;
+    s2 += s12 * 654183;
+    s3 -= s12 * 997805;
+    s4 += s12 * 136657;
+    s5 -= s12 * 683901;
+
+    carry0 = s0 >> 21;
+    s1 += carry0;
+    s0 -= carry0 << 21;
+    carry1 = s1 >> 21;
+    s2 += carry1;
+    s1 -= carry1 << 21;
+    carry2 = s2 >> 21;
+    s3 += carry2;
+    s2 -= carry2 << 21;
+    carry3 = s3 >> 21;
+    s4 += carry3;
+    s3 -= carry3 << 21;
+    carry4 = s4 >> 21;
+    s5 += carry4;
+    s4 -= carry4 << 21;
+    carry5 = s5 >> 21;
+    s6 += carry5;
+    s5 -= carry5 << 21;
+    carry6 = s6 >> 21;
+    s7 += carry6;
+    s6 -= carry6 << 21;
+    carry7 = s7 >> 21;
+    s8 += carry7;
+    s7 -= carry7 << 21;
+    carry8 = s8 >> 21;
+    s9 += carry8;
+    s8 -= carry8 << 21;
+    carry9 = s9 >> 21;
+    s10 += carry9;
+    s9 -= carry9 << 21;
+    carry10 = s10 >> 21;
+    s11 += carry10;
+    s10 -= carry10 << 21;
+
+    s[0] = (s0 >> 0) as u8;
+    s[1] = (s0 >> 8) as u8;
+    s[2] = ((s0 >> 16) | (s1 << 5)) as u8;
+    s[3] = (s1 >> 3) as u8;
+    s[4] = (s1 >> 11) as u8;
+    s[5] = ((s1 >> 19) | (s2 << 2)) as u8;
+    s[6] = (s2 >> 6) as u8;
+    s[7] = ((s2 >> 14) | (s3 << 7)) as u8;
+    s[8] = (s3 >> 1) as u8;
+    s[9] = (s3 >> 9) as u8;
+    s[10] = ((s3 >> 17) | (s4 << 4)) as u8;
+    s[11] = (s4 >> 4) as u8;
+    s[12] = (s4 >> 12) as u8;
+    s[13] = ((s4 >> 20) | (s5 << 1)) as u8;
+    s[14] = (s5 >> 7) as u8;
+    s[15] = ((s5 >> 15) | (s6 << 6)) as u8;
+    s[16] = (s6 >> 2) as u8;
+    s[17] = (s6 >> 10) as u8;
+    s[18] = ((s6 >> 18) | (s7 << 3)) as u8;
+    s[19] = (s7 >> 5) as u8;
+    s[20] = (s7 >> 13) as u8;
+    s[21] = (s8 >> 0) as u8;
+    s[22] = (s8 >> 8) as u8;
+    s[23] = ((s8 >> 16) | (s9 << 5)) as u8;
+    s[24] = (s9 >> 3) as u8;
+    s[25] = (s9 >> 11) as u8;
+    s[26] = ((s9 >> 19) | (s10 << 2)) as u8;
+    s[27] = (s10 >> 6) as u8;
+    s[28] = ((s10 >> 14) | (s11 << 7)) as u8;
+    s[29] = (s11 >> 1) as u8;
+    s[30] = (s11 >> 9) as u8;
+    s[31] = (s11 >> 17) as u8;
+}
+
+pub fn sc_reject_noncanonical(s: &[u8]) -> Result<(), Error> {
+    static L: [u8; 32] = [
+        0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde,
+        0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x10,
+    ];
+    if s.len() != 32 {
+        panic!("Invalid compressed length")
+    }
+    let mut c: u8 = 0;
+    let mut n: u8 = 1;
+
+    let mut i = 31;
+    loop {
+        c |= ((((s[i] as i32) - (L[i] as i32)) >> 8) as u8) & n;
+        n &= ((((s[i] ^ L[i]) as i32) - 1) >> 8) as u8;
+        if i == 0 {
+            break;
+        }
+        i -= 1;
+    }
+    if c != 0 {
+        Ok(())
+    } else {
+        Err(Error::NonCanonical)
+    }
+}
+
+pub fn is_identity(s: &[u8; 32]) -> bool {
+    let mut c = s[0] ^ 0x01;
+    for i in 1..31 {
+        c |= s[i];
+    }
+    c |= s[31] & 0x7f;
+    c == 0
+}
+
+static BI: [GePrecomp; 8] = [
+    GePrecomp {
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+        y_plus_x: Fe([
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+        y_minus_x: Fe([
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diff --git a/vendor/ed25519-compact/src/error.rs b/vendor/ed25519-compact/src/error.rs
new file mode 100644
index 0000000..a73392d
--- /dev/null
+++ b/vendor/ed25519-compact/src/error.rs
@@ -0,0 +1,45 @@
+use core::fmt::{self, Display};
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub enum Error {
+    /// The signature doesn't verify.
+    SignatureMismatch,
+    /// A weak public key was used.
+    WeakPublicKey,
+    /// The public key is invalid.
+    InvalidPublicKey,
+    /// The secret key is invalid.
+    InvalidSecretKey,
+    /// The signature is invalid.
+    InvalidSignature,
+    /// The seed doesn't have the expected length.
+    InvalidSeed,
+    /// The blind doesn't have the expected length.
+    InvalidBlind,
+    /// The noise doesn't have the expected length.
+    InvalidNoise,
+    /// Parse error
+    ParseError,
+    /// Non-canonical encoding
+    NonCanonical,
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for Error {}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::SignatureMismatch => write!(f, "Signature doesn't verify"),
+            Error::WeakPublicKey => write!(f, "Weak public key"),
+            Error::InvalidPublicKey => write!(f, "Invalid public key"),
+            Error::InvalidSecretKey => write!(f, "Invalid secret key"),
+            Error::InvalidSignature => write!(f, "Invalid signature"),
+            Error::InvalidSeed => write!(f, "Invalid seed length"),
+            Error::InvalidBlind => write!(f, "Invalid blind length"),
+            Error::InvalidNoise => write!(f, "Invalid noise length"),
+            Error::ParseError => write!(f, "Parse error"),
+            Error::NonCanonical => write!(f, "Non-canonical encoding"),
+        }
+    }
+}
diff --git a/vendor/ed25519-compact/src/field25519.rs b/vendor/ed25519-compact/src/field25519.rs
new file mode 100644
index 0000000..fbc6c24
--- /dev/null
+++ b/vendor/ed25519-compact/src/field25519.rs
@@ -0,0 +1,696 @@
+#![allow(unused_parens)]
+#![allow(non_camel_case_types)]
+
+use core::cmp::{Eq, PartialEq};
+use core::ops::{Add, Mul, Sub};
+
+use crate::error::*;
+
+pub type fiat_25519_u1 = u8;
+pub type fiat_25519_i1 = i8;
+pub type fiat_25519_i2 = i8;
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_addcarryx_u51(
+    out1: &mut u64,
+    out2: &mut fiat_25519_u1,
+    arg1: fiat_25519_u1,
+    arg2: u64,
+    arg3: u64,
+) {
+    let x1: u64 = (((arg1 as u64).wrapping_add(arg2)).wrapping_add(arg3));
+    let x2: u64 = (x1 & 0x7ffffffffffff);
+    let x3: fiat_25519_u1 = ((x1 >> 51) as fiat_25519_u1);
+    *out1 = x2;
+    *out2 = x3;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_subborrowx_u51(
+    out1: &mut u64,
+    out2: &mut fiat_25519_u1,
+    arg1: fiat_25519_u1,
+    arg2: u64,
+    arg3: u64,
+) {
+    let x1: i64 = ((((((arg2 as i128).wrapping_sub((arg1 as i128))) as i64) as i128)
+        .wrapping_sub((arg3 as i128))) as i64);
+    let x2: fiat_25519_i1 = ((x1 >> 51) as fiat_25519_i1);
+    let x3: u64 = (((x1 as i128) & 0x7ffffffffffff_i128) as u64);
+    *out1 = x3;
+    *out2 = ((0x0_i8.wrapping_sub((x2 as fiat_25519_i2))) as fiat_25519_u1);
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_cmovznz_u64(out1: &mut u64, arg1: fiat_25519_u1, arg2: u64, arg3: u64) {
+    let x1: fiat_25519_u1 = (!(!arg1));
+    let x2: u64 = (((((0x0_i8.wrapping_sub((x1 as fiat_25519_i2))) as fiat_25519_i1) as i128)
+        & 0xffffffffffffffff_i128) as u64);
+    let x3: u64 = ((x2 & arg3) | ((!x2) & arg2));
+    *out1 = x3;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_carry_mul(out1: &mut [u64; 5], arg1: &[u64; 5], arg2: &[u64; 5]) {
+    let x1: u128 = (((arg1[4]) as u128).wrapping_mul((((arg2[4]).wrapping_mul(0x13)) as u128)));
+    let x2: u128 = (((arg1[4]) as u128).wrapping_mul((((arg2[3]).wrapping_mul(0x13)) as u128)));
+    let x3: u128 = (((arg1[4]) as u128).wrapping_mul((((arg2[2]).wrapping_mul(0x13)) as u128)));
+    let x4: u128 = (((arg1[4]) as u128).wrapping_mul((((arg2[1]).wrapping_mul(0x13)) as u128)));
+    let x5: u128 = (((arg1[3]) as u128).wrapping_mul((((arg2[4]).wrapping_mul(0x13)) as u128)));
+    let x6: u128 = (((arg1[3]) as u128).wrapping_mul((((arg2[3]).wrapping_mul(0x13)) as u128)));
+    let x7: u128 = (((arg1[3]) as u128).wrapping_mul((((arg2[2]).wrapping_mul(0x13)) as u128)));
+    let x8: u128 = (((arg1[2]) as u128).wrapping_mul((((arg2[4]).wrapping_mul(0x13)) as u128)));
+    let x9: u128 = (((arg1[2]) as u128).wrapping_mul((((arg2[3]).wrapping_mul(0x13)) as u128)));
+    let x10: u128 = (((arg1[1]) as u128).wrapping_mul((((arg2[4]).wrapping_mul(0x13)) as u128)));
+    let x11: u128 = (((arg1[4]) as u128).wrapping_mul(((arg2[0]) as u128)));
+    let x12: u128 = (((arg1[3]) as u128).wrapping_mul(((arg2[1]) as u128)));
+    let x13: u128 = (((arg1[3]) as u128).wrapping_mul(((arg2[0]) as u128)));
+    let x14: u128 = (((arg1[2]) as u128).wrapping_mul(((arg2[2]) as u128)));
+    let x15: u128 = (((arg1[2]) as u128).wrapping_mul(((arg2[1]) as u128)));
+    let x16: u128 = (((arg1[2]) as u128).wrapping_mul(((arg2[0]) as u128)));
+    let x17: u128 = (((arg1[1]) as u128).wrapping_mul(((arg2[3]) as u128)));
+    let x18: u128 = (((arg1[1]) as u128).wrapping_mul(((arg2[2]) as u128)));
+    let x19: u128 = (((arg1[1]) as u128).wrapping_mul(((arg2[1]) as u128)));
+    let x20: u128 = (((arg1[1]) as u128).wrapping_mul(((arg2[0]) as u128)));
+    let x21: u128 = (((arg1[0]) as u128).wrapping_mul(((arg2[4]) as u128)));
+    let x22: u128 = (((arg1[0]) as u128).wrapping_mul(((arg2[3]) as u128)));
+    let x23: u128 = (((arg1[0]) as u128).wrapping_mul(((arg2[2]) as u128)));
+    let x24: u128 = (((arg1[0]) as u128).wrapping_mul(((arg2[1]) as u128)));
+    let x25: u128 = (((arg1[0]) as u128).wrapping_mul(((arg2[0]) as u128)));
+    let x26: u128 =
+        (x25.wrapping_add((x10.wrapping_add((x9.wrapping_add((x7.wrapping_add(x4))))))));
+    let x27: u64 = ((x26 >> 51) as u64);
+    let x28: u64 = ((x26 & 0x7ffffffffffff_u128) as u64);
+    let x29: u128 =
+        (x21.wrapping_add((x17.wrapping_add((x14.wrapping_add((x12.wrapping_add(x11))))))));
+    let x30: u128 =
+        (x22.wrapping_add((x18.wrapping_add((x15.wrapping_add((x13.wrapping_add(x1))))))));
+    let x31: u128 =
+        (x23.wrapping_add((x19.wrapping_add((x16.wrapping_add((x5.wrapping_add(x2))))))));
+    let x32: u128 =
+        (x24.wrapping_add((x20.wrapping_add((x8.wrapping_add((x6.wrapping_add(x3))))))));
+    let x33: u128 = ((x27 as u128).wrapping_add(x32));
+    let x34: u64 = ((x33 >> 51) as u64);
+    let x35: u64 = ((x33 & 0x7ffffffffffff_u128) as u64);
+    let x36: u128 = ((x34 as u128).wrapping_add(x31));
+    let x37: u64 = ((x36 >> 51) as u64);
+    let x38: u64 = ((x36 & 0x7ffffffffffff_u128) as u64);
+    let x39: u128 = ((x37 as u128).wrapping_add(x30));
+    let x40: u64 = ((x39 >> 51) as u64);
+    let x41: u64 = ((x39 & 0x7ffffffffffff_u128) as u64);
+    let x42: u128 = ((x40 as u128).wrapping_add(x29));
+    let x43: u64 = ((x42 >> 51) as u64);
+    let x44: u64 = ((x42 & 0x7ffffffffffff_u128) as u64);
+    let x45: u64 = (x43.wrapping_mul(0x13));
+    let x46: u64 = (x28.wrapping_add(x45));
+    let x47: u64 = (x46 >> 51);
+    let x48: u64 = (x46 & 0x7ffffffffffff);
+    let x49: u64 = (x47.wrapping_add(x35));
+    let x50: fiat_25519_u1 = ((x49 >> 51) as fiat_25519_u1);
+    let x51: u64 = (x49 & 0x7ffffffffffff);
+    let x52: u64 = ((x50 as u64).wrapping_add(x38));
+    out1[0] = x48;
+    out1[1] = x51;
+    out1[2] = x52;
+    out1[3] = x41;
+    out1[4] = x44;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_carry_square(out1: &mut [u64; 5], arg1: &[u64; 5]) {
+    let x1: u64 = ((arg1[4]).wrapping_mul(0x13));
+    let x2: u64 = (x1.wrapping_mul(0x2));
+    let x3: u64 = ((arg1[4]).wrapping_mul(0x2));
+    let x4: u64 = ((arg1[3]).wrapping_mul(0x13));
+    let x5: u64 = (x4.wrapping_mul(0x2));
+    let x6: u64 = ((arg1[3]).wrapping_mul(0x2));
+    let x7: u64 = ((arg1[2]).wrapping_mul(0x2));
+    let x8: u64 = ((arg1[1]).wrapping_mul(0x2));
+    let x9: u128 = (((arg1[4]) as u128).wrapping_mul((x1 as u128)));
+    let x10: u128 = (((arg1[3]) as u128).wrapping_mul((x2 as u128)));
+    let x11: u128 = (((arg1[3]) as u128).wrapping_mul((x4 as u128)));
+    let x12: u128 = (((arg1[2]) as u128).wrapping_mul((x2 as u128)));
+    let x13: u128 = (((arg1[2]) as u128).wrapping_mul((x5 as u128)));
+    let x14: u128 = (((arg1[2]) as u128).wrapping_mul(((arg1[2]) as u128)));
+    let x15: u128 = (((arg1[1]) as u128).wrapping_mul((x2 as u128)));
+    let x16: u128 = (((arg1[1]) as u128).wrapping_mul((x6 as u128)));
+    let x17: u128 = (((arg1[1]) as u128).wrapping_mul((x7 as u128)));
+    let x18: u128 = (((arg1[1]) as u128).wrapping_mul(((arg1[1]) as u128)));
+    let x19: u128 = (((arg1[0]) as u128).wrapping_mul((x3 as u128)));
+    let x20: u128 = (((arg1[0]) as u128).wrapping_mul((x6 as u128)));
+    let x21: u128 = (((arg1[0]) as u128).wrapping_mul((x7 as u128)));
+    let x22: u128 = (((arg1[0]) as u128).wrapping_mul((x8 as u128)));
+    let x23: u128 = (((arg1[0]) as u128).wrapping_mul(((arg1[0]) as u128)));
+    let x24: u128 = (x23.wrapping_add((x15.wrapping_add(x13))));
+    let x25: u64 = ((x24 >> 51) as u64);
+    let x26: u64 = ((x24 & 0x7ffffffffffff_u128) as u64);
+    let x27: u128 = (x19.wrapping_add((x16.wrapping_add(x14))));
+    let x28: u128 = (x20.wrapping_add((x17.wrapping_add(x9))));
+    let x29: u128 = (x21.wrapping_add((x18.wrapping_add(x10))));
+    let x30: u128 = (x22.wrapping_add((x12.wrapping_add(x11))));
+    let x31: u128 = ((x25 as u128).wrapping_add(x30));
+    let x32: u64 = ((x31 >> 51) as u64);
+    let x33: u64 = ((x31 & 0x7ffffffffffff_u128) as u64);
+    let x34: u128 = ((x32 as u128).wrapping_add(x29));
+    let x35: u64 = ((x34 >> 51) as u64);
+    let x36: u64 = ((x34 & 0x7ffffffffffff_u128) as u64);
+    let x37: u128 = ((x35 as u128).wrapping_add(x28));
+    let x38: u64 = ((x37 >> 51) as u64);
+    let x39: u64 = ((x37 & 0x7ffffffffffff_u128) as u64);
+    let x40: u128 = ((x38 as u128).wrapping_add(x27));
+    let x41: u64 = ((x40 >> 51) as u64);
+    let x42: u64 = ((x40 & 0x7ffffffffffff_u128) as u64);
+    let x43: u64 = (x41.wrapping_mul(0x13));
+    let x44: u64 = (x26.wrapping_add(x43));
+    let x45: u64 = (x44 >> 51);
+    let x46: u64 = (x44 & 0x7ffffffffffff);
+    let x47: u64 = (x45.wrapping_add(x33));
+    let x48: fiat_25519_u1 = ((x47 >> 51) as fiat_25519_u1);
+    let x49: u64 = (x47 & 0x7ffffffffffff);
+    let x50: u64 = ((x48 as u64).wrapping_add(x36));
+    out1[0] = x46;
+    out1[1] = x49;
+    out1[2] = x50;
+    out1[3] = x39;
+    out1[4] = x42;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_carry(out1: &mut [u64; 5], arg1: &[u64; 5]) {
+    let x1: u64 = (arg1[0]);
+    let x2: u64 = ((x1 >> 51).wrapping_add((arg1[1])));
+    let x3: u64 = ((x2 >> 51).wrapping_add((arg1[2])));
+    let x4: u64 = ((x3 >> 51).wrapping_add((arg1[3])));
+    let x5: u64 = ((x4 >> 51).wrapping_add((arg1[4])));
+    let x6: u64 = ((x1 & 0x7ffffffffffff).wrapping_add(((x5 >> 51).wrapping_mul(0x13))));
+    let x7: u64 = ((((x6 >> 51) as fiat_25519_u1) as u64).wrapping_add((x2 & 0x7ffffffffffff)));
+    let x8: u64 = (x6 & 0x7ffffffffffff);
+    let x9: u64 = (x7 & 0x7ffffffffffff);
+    let x10: u64 = ((((x7 >> 51) as fiat_25519_u1) as u64).wrapping_add((x3 & 0x7ffffffffffff)));
+    let x11: u64 = (x4 & 0x7ffffffffffff);
+    let x12: u64 = (x5 & 0x7ffffffffffff);
+    out1[0] = x8;
+    out1[1] = x9;
+    out1[2] = x10;
+    out1[3] = x11;
+    out1[4] = x12;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_add(out1: &mut [u64; 5], arg1: &[u64; 5], arg2: &[u64; 5]) {
+    let x1: u64 = ((arg1[0]).wrapping_add((arg2[0])));
+    let x2: u64 = ((arg1[1]).wrapping_add((arg2[1])));
+    let x3: u64 = ((arg1[2]).wrapping_add((arg2[2])));
+    let x4: u64 = ((arg1[3]).wrapping_add((arg2[3])));
+    let x5: u64 = ((arg1[4]).wrapping_add((arg2[4])));
+    out1[0] = x1;
+    out1[1] = x2;
+    out1[2] = x3;
+    out1[3] = x4;
+    out1[4] = x5;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_sub(out1: &mut [u64; 5], arg1: &[u64; 5], arg2: &[u64; 5]) {
+    let x1: u64 = ((0xfffffffffffdau64.wrapping_add((arg1[0]))).wrapping_sub((arg2[0])));
+    let x2: u64 = ((0xffffffffffffeu64.wrapping_add((arg1[1]))).wrapping_sub((arg2[1])));
+    let x3: u64 = ((0xffffffffffffeu64.wrapping_add((arg1[2]))).wrapping_sub((arg2[2])));
+    let x4: u64 = ((0xffffffffffffeu64.wrapping_add((arg1[3]))).wrapping_sub((arg2[3])));
+    let x5: u64 = ((0xffffffffffffeu64.wrapping_add((arg1[4]))).wrapping_sub((arg2[4])));
+    out1[0] = x1;
+    out1[1] = x2;
+    out1[2] = x3;
+    out1[3] = x4;
+    out1[4] = x5;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_opp(out1: &mut [u64; 5], arg1: &[u64; 5]) {
+    let x1: u64 = (0xfffffffffffdau64.wrapping_sub((arg1[0])));
+    let x2: u64 = (0xffffffffffffeu64.wrapping_sub((arg1[1])));
+    let x3: u64 = (0xffffffffffffeu64.wrapping_sub((arg1[2])));
+    let x4: u64 = (0xffffffffffffeu64.wrapping_sub((arg1[3])));
+    let x5: u64 = (0xffffffffffffeu64.wrapping_sub((arg1[4])));
+    out1[0] = x1;
+    out1[1] = x2;
+    out1[2] = x3;
+    out1[3] = x4;
+    out1[4] = x5;
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn fiat_25519_selectznz(
+    out1: &mut [u64; 5],
+    arg1: fiat_25519_u1,
+    arg2: &[u64; 5],
+    arg3: &[u64; 5],
+) {
+    let mut x1: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x1, arg1, (arg2[0]), (arg3[0]));
+    let mut x2: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x2, arg1, (arg2[1]), (arg3[1]));
+    let mut x3: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x3, arg1, (arg2[2]), (arg3[2]));
+    let mut x4: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x4, arg1, (arg2[3]), (arg3[3]));
+    let mut x5: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x5, arg1, (arg2[4]), (arg3[4]));
+    out1[0] = x1;
+    out1[1] = x2;
+    out1[2] = x3;
+    out1[3] = x4;
+    out1[4] = x5;
+}
+
+pub fn fiat_25519_to_bytes(out1: &mut [u8; 32], arg1: &[u64; 5]) {
+    let mut x1: u64 = 0;
+    let mut x2: fiat_25519_u1 = 0;
+    fiat_25519_subborrowx_u51(&mut x1, &mut x2, 0x0, (arg1[0]), 0x7ffffffffffed);
+    let mut x3: u64 = 0;
+    let mut x4: fiat_25519_u1 = 0;
+    fiat_25519_subborrowx_u51(&mut x3, &mut x4, x2, (arg1[1]), 0x7ffffffffffff);
+    let mut x5: u64 = 0;
+    let mut x6: fiat_25519_u1 = 0;
+    fiat_25519_subborrowx_u51(&mut x5, &mut x6, x4, (arg1[2]), 0x7ffffffffffff);
+    let mut x7: u64 = 0;
+    let mut x8: fiat_25519_u1 = 0;
+    fiat_25519_subborrowx_u51(&mut x7, &mut x8, x6, (arg1[3]), 0x7ffffffffffff);
+    let mut x9: u64 = 0;
+    let mut x10: fiat_25519_u1 = 0;
+    fiat_25519_subborrowx_u51(&mut x9, &mut x10, x8, (arg1[4]), 0x7ffffffffffff);
+    let mut x11: u64 = 0;
+    fiat_25519_cmovznz_u64(&mut x11, x10, 0x0_u64, 0xffffffffffffffff);
+    let mut x12: u64 = 0;
+    let mut x13: fiat_25519_u1 = 0;
+    fiat_25519_addcarryx_u51(&mut x12, &mut x13, 0x0, x1, (x11 & 0x7ffffffffffed));
+    let mut x14: u64 = 0;
+    let mut x15: fiat_25519_u1 = 0;
+    fiat_25519_addcarryx_u51(&mut x14, &mut x15, x13, x3, (x11 & 0x7ffffffffffff));
+    let mut x16: u64 = 0;
+    let mut x17: fiat_25519_u1 = 0;
+    fiat_25519_addcarryx_u51(&mut x16, &mut x17, x15, x5, (x11 & 0x7ffffffffffff));
+    let mut x18: u64 = 0;
+    let mut x19: fiat_25519_u1 = 0;
+    fiat_25519_addcarryx_u51(&mut x18, &mut x19, x17, x7, (x11 & 0x7ffffffffffff));
+    let mut x20: u64 = 0;
+    let mut x21: fiat_25519_u1 = 0;
+    fiat_25519_addcarryx_u51(&mut x20, &mut x21, x19, x9, (x11 & 0x7ffffffffffff));
+    let x22: u64 = (x20 << 4);
+    let x23: u64 = (x18.wrapping_mul(0x2_u64));
+    let x24: u64 = (x16 << 6);
+    let x25: u64 = (x14 << 3);
+    let x26: u8 = ((x12 & 0xff_u64) as u8);
+    let x27: u64 = (x12 >> 8);
+    let x28: u8 = ((x27 & 0xff_u64) as u8);
+    let x29: u64 = (x27 >> 8);
+    let x30: u8 = ((x29 & 0xff_u64) as u8);
+    let x31: u64 = (x29 >> 8);
+    let x32: u8 = ((x31 & 0xff_u64) as u8);
+    let x33: u64 = (x31 >> 8);
+    let x34: u8 = ((x33 & 0xff_u64) as u8);
+    let x35: u64 = (x33 >> 8);
+    let x36: u8 = ((x35 & 0xff_u64) as u8);
+    let x37: u8 = ((x35 >> 8) as u8);
+    let x38: u64 = (x25.wrapping_add((x37 as u64)));
+    let x39: u8 = ((x38 & 0xff_u64) as u8);
+    let x40: u64 = (x38 >> 8);
+    let x41: u8 = ((x40 & 0xff_u64) as u8);
+    let x42: u64 = (x40 >> 8);
+    let x43: u8 = ((x42 & 0xff_u64) as u8);
+    let x44: u64 = (x42 >> 8);
+    let x45: u8 = ((x44 & 0xff_u64) as u8);
+    let x46: u64 = (x44 >> 8);
+    let x47: u8 = ((x46 & 0xff_u64) as u8);
+    let x48: u64 = (x46 >> 8);
+    let x49: u8 = ((x48 & 0xff_u64) as u8);
+    let x50: u8 = ((x48 >> 8) as u8);
+    let x51: u64 = (x24.wrapping_add((x50 as u64)));
+    let x52: u8 = ((x51 & 0xff_u64) as u8);
+    let x53: u64 = (x51 >> 8);
+    let x54: u8 = ((x53 & 0xff_u64) as u8);
+    let x55: u64 = (x53 >> 8);
+    let x56: u8 = ((x55 & 0xff_u64) as u8);
+    let x57: u64 = (x55 >> 8);
+    let x58: u8 = ((x57 & 0xff_u64) as u8);
+    let x59: u64 = (x57 >> 8);
+    let x60: u8 = ((x59 & 0xff_u64) as u8);
+    let x61: u64 = (x59 >> 8);
+    let x62: u8 = ((x61 & 0xff_u64) as u8);
+    let x63: u64 = (x61 >> 8);
+    let x64: u8 = ((x63 & 0xff_u64) as u8);
+    let x65: fiat_25519_u1 = ((x63 >> 8) as fiat_25519_u1);
+    let x66: u64 = (x23.wrapping_add((x65 as u64)));
+    let x67: u8 = ((x66 & 0xff_u64) as u8);
+    let x68: u64 = (x66 >> 8);
+    let x69: u8 = ((x68 & 0xff_u64) as u8);
+    let x70: u64 = (x68 >> 8);
+    let x71: u8 = ((x70 & 0xff_u64) as u8);
+    let x72: u64 = (x70 >> 8);
+    let x73: u8 = ((x72 & 0xff_u64) as u8);
+    let x74: u64 = (x72 >> 8);
+    let x75: u8 = ((x74 & 0xff_u64) as u8);
+    let x76: u64 = (x74 >> 8);
+    let x77: u8 = ((x76 & 0xff_u64) as u8);
+    let x78: u8 = ((x76 >> 8) as u8);
+    let x79: u64 = (x22.wrapping_add((x78 as u64)));
+    let x80: u8 = ((x79 & 0xff_u64) as u8);
+    let x81: u64 = (x79 >> 8);
+    let x82: u8 = ((x81 & 0xff_u64) as u8);
+    let x83: u64 = (x81 >> 8);
+    let x84: u8 = ((x83 & 0xff_u64) as u8);
+    let x85: u64 = (x83 >> 8);
+    let x86: u8 = ((x85 & 0xff_u64) as u8);
+    let x87: u64 = (x85 >> 8);
+    let x88: u8 = ((x87 & 0xff_u64) as u8);
+    let x89: u64 = (x87 >> 8);
+    let x90: u8 = ((x89 & 0xff_u64) as u8);
+    let x91: u8 = ((x89 >> 8) as u8);
+    out1[0] = x26;
+    out1[1] = x28;
+    out1[2] = x30;
+    out1[3] = x32;
+    out1[4] = x34;
+    out1[5] = x36;
+    out1[6] = x39;
+    out1[7] = x41;
+    out1[8] = x43;
+    out1[9] = x45;
+    out1[10] = x47;
+    out1[11] = x49;
+    out1[12] = x52;
+    out1[13] = x54;
+    out1[14] = x56;
+    out1[15] = x58;
+    out1[16] = x60;
+    out1[17] = x62;
+    out1[18] = x64;
+    out1[19] = x67;
+    out1[20] = x69;
+    out1[21] = x71;
+    out1[22] = x73;
+    out1[23] = x75;
+    out1[24] = x77;
+    out1[25] = x80;
+    out1[26] = x82;
+    out1[27] = x84;
+    out1[28] = x86;
+    out1[29] = x88;
+    out1[30] = x90;
+    out1[31] = x91;
+}
+
+#[derive(Clone, Default, Copy)]
+pub struct Fe(pub [u64; 5]);
+
+impl PartialEq for Fe {
+    fn eq(&self, other: &Fe) -> bool {
+        let &Fe(self_elems) = self;
+        let &Fe(other_elems) = other;
+        self_elems == other_elems
+    }
+}
+impl Eq for Fe {}
+
+pub static FE_ZERO: Fe = Fe([0, 0, 0, 0, 0]);
+pub static FE_ONE: Fe = Fe([1, 0, 0, 0, 0]);
+pub static FE_SQRTM1: Fe = Fe([
+    1718705420411056,
+    234908883556509,
+    2233514472574048,
+    2117202627021982,
+    765476049583133,
+]);
+pub(crate) static FE_D: Fe = Fe([
+    929955233495203,
+    466365720129213,
+    1662059464998953,
+    2033849074728123,
+    1442794654840575,
+]);
+pub(crate) static FE_D2: Fe = Fe([
+    1859910466990425,
+    932731440258426,
+    1072319116312658,
+    1815898335770999,
+    633789495995903,
+]);
+
+#[cfg(feature = "x25519")]
+pub(crate) static FE_CURVE25519_BASEPOINT: Fe = Fe([9, 0, 0, 0, 0]);
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+fn load_8u(s: &[u8]) -> u64 {
+    (s[0] as u64)
+        | ((s[1] as u64) << 8)
+        | ((s[2] as u64) << 16)
+        | ((s[3] as u64) << 24)
+        | ((s[4] as u64) << 32)
+        | ((s[5] as u64) << 40)
+        | ((s[6] as u64) << 48)
+        | ((s[7] as u64) << 56)
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn load_4u(s: &[u8]) -> u64 {
+    (s[0] as u64) | ((s[1] as u64) << 8) | ((s[2] as u64) << 16) | ((s[3] as u64) << 24)
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn load_4i(s: &[u8]) -> i64 {
+    load_4u(s) as i64
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn load_3u(s: &[u8]) -> u64 {
+    (s[0] as u64) | ((s[1] as u64) << 8) | ((s[2] as u64) << 16)
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline)]
+pub fn load_3i(s: &[u8]) -> i64 {
+    load_3u(s) as i64
+}
+
+impl Add for Fe {
+    type Output = Fe;
+
+    fn add(self, _rhs: Fe) -> Fe {
+        let Fe(f) = self;
+        let Fe(g) = _rhs;
+        let mut h = Fe::default();
+        fiat_25519_add(&mut h.0, &f, &g);
+        h
+    }
+}
+
+impl Sub for Fe {
+    type Output = Fe;
+
+    fn sub(self, _rhs: Fe) -> Fe {
+        let Fe(f) = self;
+        let Fe(g) = _rhs;
+        let mut h = Fe::default();
+        fiat_25519_sub(&mut h.0, &f, &g);
+        h.carry()
+    }
+}
+
+impl Mul for Fe {
+    type Output = Fe;
+
+    fn mul(self, _rhs: Fe) -> Fe {
+        let Fe(f) = self;
+        let Fe(g) = _rhs;
+        let mut h = Fe::default();
+        fiat_25519_carry_mul(&mut h.0, &f, &g);
+        h
+    }
+}
+
+impl Fe {
+    pub fn from_bytes(s: &[u8]) -> Fe {
+        if s.len() != 32 {
+            panic!("Invalid compressed length")
+        }
+        let mut h = Fe::default();
+        let mask = 0x7ffffffffffff;
+        h.0[0] = load_8u(&s[0..]) & mask;
+        h.0[1] = (load_8u(&s[6..]) >> 3) & mask;
+        h.0[2] = (load_8u(&s[12..]) >> 6) & mask;
+        h.0[3] = (load_8u(&s[19..]) >> 1) & mask;
+        h.0[4] = (load_8u(&s[24..]) >> 12) & mask;
+        h
+    }
+
+    pub fn to_bytes(&self) -> [u8; 32] {
+        let &Fe(es) = &self.carry();
+        let mut s_ = [0u8; 32];
+        fiat_25519_to_bytes(&mut s_, &es);
+        s_
+    }
+
+    pub fn carry(&self) -> Fe {
+        let mut h = Fe::default();
+        fiat_25519_carry(&mut h.0, &self.0);
+        h
+    }
+
+    pub fn maybe_set(&mut self, other: &Fe, do_swap: u8) {
+        let &mut Fe(f) = self;
+        let &Fe(g) = other;
+        let mut t = [0u64; 5];
+        fiat_25519_selectznz(&mut t, do_swap, &f, &g);
+        self.0 = t
+    }
+
+    pub fn square(&self) -> Fe {
+        let &Fe(f) = &self;
+        let mut h = Fe::default();
+        fiat_25519_carry_square(&mut h.0, f);
+        h
+    }
+
+    pub fn square_and_double(&self) -> Fe {
+        let h = self.square();
+        (h + h)
+    }
+
+    pub fn invert(&self) -> Fe {
+        let z1 = *self;
+        let z2 = z1.square();
+        let z8 = z2.square().square();
+        let z9 = z1 * z8;
+        let z11 = z2 * z9;
+        let z22 = z11.square();
+        let z_5_0 = z9 * z22;
+        let z_10_5 = (0..5).fold(z_5_0, |z_5_n, _| z_5_n.square());
+        let z_10_0 = z_10_5 * z_5_0;
+        let z_20_10 = (0..10).fold(z_10_0, |x, _| x.square());
+        let z_20_0 = z_20_10 * z_10_0;
+        let z_40_20 = (0..20).fold(z_20_0, |x, _| x.square());
+        let z_40_0 = z_40_20 * z_20_0;
+        let z_50_10 = (0..10).fold(z_40_0, |x, _| x.square());
+        let z_50_0 = z_50_10 * z_10_0;
+        let z_100_50 = (0..50).fold(z_50_0, |x, _| x.square());
+        let z_100_0 = z_100_50 * z_50_0;
+        let z_200_100 = (0..100).fold(z_100_0, |x, _| x.square());
+        let z_200_0 = z_200_100 * z_100_0;
+        let z_250_50 = (0..50).fold(z_200_0, |x, _| x.square());
+        let z_250_0 = z_250_50 * z_50_0;
+        let z_255_5 = (0..5).fold(z_250_0, |x, _| x.square());
+        let z_255_21 = z_255_5 * z11;
+        z_255_21
+    }
+
+    pub fn is_zero(&self) -> bool {
+        self.to_bytes().iter().fold(0, |acc, x| acc | x) == 0
+    }
+
+    pub fn is_negative(&self) -> bool {
+        (self.to_bytes()[0] & 1) != 0
+    }
+
+    pub fn neg(&self) -> Fe {
+        let &Fe(f) = &self;
+        let mut h = Fe::default();
+        fiat_25519_opp(&mut h.0, f);
+        h
+    }
+
+    pub fn pow25523(&self) -> Fe {
+        let z2 = self.square();
+        let z8 = (0..2).fold(z2, |x, _| x.square());
+        let z9 = *self * z8;
+        let z11 = z2 * z9;
+        let z22 = z11.square();
+        let z_5_0 = z9 * z22;
+        let z_10_5 = (0..5).fold(z_5_0, |x, _| x.square());
+        let z_10_0 = z_10_5 * z_5_0;
+        let z_20_10 = (0..10).fold(z_10_0, |x, _| x.square());
+        let z_20_0 = z_20_10 * z_10_0;
+        let z_40_20 = (0..20).fold(z_20_0, |x, _| x.square());
+        let z_40_0 = z_40_20 * z_20_0;
+        let z_50_10 = (0..10).fold(z_40_0, |x, _| x.square());
+        let z_50_0 = z_50_10 * z_10_0;
+        let z_100_50 = (0..50).fold(z_50_0, |x, _| x.square());
+        let z_100_0 = z_100_50 * z_50_0;
+        let z_200_100 = (0..100).fold(z_100_0, |x, _| x.square());
+        let z_200_0 = z_200_100 * z_100_0;
+        let z_250_50 = (0..50).fold(z_200_0, |x, _| x.square());
+        let z_250_0 = z_250_50 * z_50_0;
+        let z_252_2 = (0..2).fold(z_250_0, |x, _| x.square());
+        let z_252_3 = z_252_2 * *self;
+
+        z_252_3
+    }
+
+    #[cfg(feature = "x25519")]
+    #[inline]
+    pub fn cswap2(a0: &mut Fe, b0: &mut Fe, a1: &mut Fe, b1: &mut Fe, c: u8) {
+        let mask: u64 = 0u64.wrapping_sub(c as _);
+        let mut x0 = *a0;
+        let mut x1 = *a1;
+        for i in 0..5 {
+            x0.0[i] ^= b0.0[i];
+            x1.0[i] ^= b1.0[i];
+        }
+        for i in 0..5 {
+            x0.0[i] &= mask;
+            x1.0[i] &= mask;
+        }
+        for i in 0..5 {
+            a0.0[i] ^= x0.0[i];
+            b0.0[i] ^= x0.0[i];
+            a1.0[i] ^= x1.0[i];
+            b1.0[i] ^= x1.0[i];
+        }
+    }
+
+    #[cfg(feature = "x25519")]
+    #[inline]
+    pub fn mul32(&self, n: u32) -> Fe {
+        let sn = n as u128;
+        let mut fe = Fe::default();
+        let mut x: u128 = 8;
+        for i in 0..5 {
+            x = self.0[i] as u128 * sn + (x >> 51);
+            fe.0[i] = (x as u64) & 0x7ffffffffffff;
+        }
+        fe.0[0] += (x >> 51) as u64 * 19;
+        fe
+    }
+
+    pub fn reject_noncanonical(s: &[u8]) -> Result<(), Error> {
+        if s.len() != 32 {
+            panic!("Invalid compressed length")
+        }
+        let mut c = s[31];
+        c ^= 0x7f;
+        let mut i: usize = 30;
+        while i > 0 {
+            c |= s[i] ^ 0xff;
+            i -= 1;
+        }
+        c = ((c as u16).wrapping_sub(1) >> 8) as u8;
+        let d = (((0xed - 1) as u16).wrapping_sub(s[0] as u16) >> 8) as u8;
+        if c & d & 1 == 0 {
+            Ok(())
+        } else {
+            Err(Error::NonCanonical)
+        }
+    }
+}
diff --git a/vendor/ed25519-compact/src/lib.rs b/vendor/ed25519-compact/src/lib.rs
new file mode 100644
index 0000000..f00e6ee
--- /dev/null
+++ b/vendor/ed25519-compact/src/lib.rs
@@ -0,0 +1,144 @@
+//! A compact Ed25519 and X25519 implementation for Rust.
+//!
+//! * Formally-verified Curve25519 field arithmetic
+//! * `no_std`-friendly
+//! * WebAssembly-friendly
+//! * Compute@Edge-friendly
+//! * Lightweight
+//! * Zero dependencies if randomness is provided by the application
+//! * Only one portable dependency (`getrandom`) if not
+//! * Supports incremental signatures (streaming API)
+//! * Safe and simple Rust interface.
+//!
+//! Example usage:
+//!
+//! ```rust
+//! use ed25519_compact::*;
+//!
+//! #[cfg(feature = "random")]
+//! fn test() {
+//! // A message to sign and verify.
+//! let message = b"test";
+//!
+//! // Generates a new key pair using a random seed.
+//! // A given seed will always produce the same key pair.
+//! let key_pair = KeyPair::from_seed(Seed::generate());
+//!
+//! // Computes a signature for this message using the secret part of the key pair.
+//! let signature = key_pair.sk.sign(message, Some(Noise::generate()));
+//!
+//! // Verifies the signature using the public part of the key pair.
+//! key_pair
+//!     .pk
+//!     .verify(message, &signature)
+//!     .expect("Signature didn't verify");
+//!
+//! // Verification of a different message using the same signature and public key fails.
+//! key_pair
+//!     .pk
+//!     .verify(b"A different message", &signature)
+//!     .expect_err("Signature shouldn't verify");
+//!
+//! // All these structures can be viewed as raw bytes simply by dereferencing them:
+//! let signature_as_bytes: &[u8] = signature.as_ref();
+//! println!("Signature as bytes: {:?}", signature_as_bytes);
+//!
+//! }
+//!
+//! #[cfg(not(feature = "random"))]
+//! fn test() {}
+//!
+//! test()
+//! ```
+//!
+//! ## Incremental API example usage
+//!
+//! Messages can also be supplied as multiple parts (streaming API) in order to
+//! handle large messages without using much memory:
+//!
+//! ```rust
+//! use ed25519_compact::*;
+//!
+//! #[cfg(feature = "random")]
+//! fn test() {
+//! /// Creates a new key pair.
+//! let kp = KeyPair::generate();
+//!
+//! /// Create a state for an incremental signer.
+//! let mut st = kp.sk.sign_incremental(Noise::default());
+//!
+//! /// Feed the message as any number of chunks, and sign the concatenation.
+//! st.absorb("mes");
+//! st.absorb("sage");
+//! let signature = st.sign();
+//!
+//! /// Create a state for an incremental verifier.
+//! let mut st = kp.pk.verify_incremental(&signature).unwrap();
+//!
+//! /// Feed the message as any number of chunks, and verify the concatenation.
+//! st.absorb("mess");
+//! st.absorb("age");
+//! assert!(st.verify().is_ok());
+//! }
+//!
+//! #[cfg(not(feature = "random"))]
+//! fn test() {}
+//!
+//! test()
+//! ```
+//!
+//! Cargo features:
+//!
+//! * `self-verify`: after having computed a new signature, verify that is it
+//!   valid. This is slower, but improves resilience against fault attacks. It
+//!   is enabled by default on WebAssembly targets.
+//! * `std`: disables `no_std` compatibility in order to make errors implement
+//!   the standard `Error` trait.
+//! * `random` (enabled by default): adds `Default` and `generate`
+//!   implementations to the `Seed` and `Noise` objects, in order to securely
+//!   create random keys and noise.
+//! * `traits`: add support for the traits from the ed25519 and signature
+//!   crates.
+//! * `pem`: add support for importing/exporting keys as OpenSSL-compatible PEM
+//!   files.
+//! * `blind-keys`: add support for key blinding.
+//! * `opt_size`: Enable size optimizations (based on benchmarks, 8-15% size
+//!   reduction at the cost of 6.5-7% performance).
+//! * `x25519`: Enable support for the X25519 key exchange system.
+//! * `disable-signatures`: Disable support for signatures, and only compile
+//!   support for X25519.
+
+#![cfg_attr(not(feature = "std"), no_std)]
+#![allow(
+    clippy::needless_range_loop,
+    clippy::many_single_char_names,
+    clippy::unreadable_literal,
+    clippy::let_and_return,
+    clippy::needless_lifetimes,
+    clippy::cast_lossless,
+    clippy::suspicious_arithmetic_impl,
+    clippy::identity_op
+)]
+
+mod common;
+mod error;
+mod field25519;
+mod sha512;
+
+pub use crate::common::*;
+pub use crate::error::*;
+
+#[cfg(not(feature = "disable-signatures"))]
+mod ed25519;
+#[cfg(not(feature = "disable-signatures"))]
+mod edwards25519;
+
+#[cfg(not(feature = "disable-signatures"))]
+pub use crate::ed25519::*;
+
+#[cfg(feature = "x25519")]
+pub mod x25519;
+
+#[cfg(not(feature = "disable-signatures"))]
+#[cfg(feature = "pem")]
+mod pem;
diff --git a/vendor/ed25519-compact/src/pem.rs b/vendor/ed25519-compact/src/pem.rs
new file mode 100644
index 0000000..4bcd13f
--- /dev/null
+++ b/vendor/ed25519-compact/src/pem.rs
@@ -0,0 +1,154 @@
+#[cfg(feature = "std")]
+use ct_codecs::Encoder;
+use ct_codecs::{Base64, Decoder};
+
+use super::{Error, KeyPair, PublicKey, SecretKey, Seed};
+
+const DER_HEADER_SK: [u8; 16] = [48, 46, 2, 1, 0, 48, 5, 6, 3, 43, 101, 112, 4, 34, 4, 32];
+
+const DER_HEADER_PK: [u8; 12] = [48, 42, 48, 5, 6, 3, 43, 101, 112, 3, 33, 0];
+
+impl KeyPair {
+    /// Import a key pair from an OpenSSL-compatible DER file.
+    pub fn from_der(der: &[u8]) -> Result<Self, Error> {
+        if der.len() != DER_HEADER_SK.len() + Seed::BYTES || der[0..16] != DER_HEADER_SK {
+            return Err(Error::ParseError);
+        }
+        let mut seed = [0u8; Seed::BYTES];
+        seed.copy_from_slice(&der[16..]);
+        let kp = KeyPair::from_seed(Seed::new(seed));
+        Ok(kp)
+    }
+
+    /// Import a key pair from an OpenSSL-compatible PEM file.
+    pub fn from_pem(pem: &str) -> Result<Self, Error> {
+        let mut it = pem.split("-----BEGIN PRIVATE KEY-----");
+        let _ = it.next().ok_or(Error::ParseError)?;
+        let inner = it.next().ok_or(Error::ParseError)?;
+        let mut it = inner.split("-----END PRIVATE KEY-----");
+        let b64 = it.next().ok_or(Error::ParseError)?;
+        let _ = it.next().ok_or(Error::ParseError)?;
+        let mut der = [0u8; 16 + Seed::BYTES];
+        Base64::decode(&mut der, b64, Some(b"\r\n\t ")).map_err(|_| Error::ParseError)?;
+        Self::from_der(&der)
+    }
+
+    /// Export a key pair as an OpenSSL-compatible PEM file.
+    #[cfg(feature = "std")]
+    pub fn to_pem(&self) -> String {
+        format!("{}\n{}\n", self.sk.to_pem().trim(), self.pk.to_pem().trim())
+    }
+}
+
+impl SecretKey {
+    /// Import a secret key from an OpenSSL-compatible DER file.
+    pub fn from_der(der: &[u8]) -> Result<Self, Error> {
+        let kp = KeyPair::from_der(der)?;
+        Ok(kp.sk)
+    }
+
+    /// Import a secret key from an OpenSSL-compatible PEM file.
+    pub fn from_pem(pem: &str) -> Result<Self, Error> {
+        let kp = KeyPair::from_pem(pem)?;
+        Ok(kp.sk)
+    }
+
+    /// Export a secret key as an OpenSSL-compatible DER file.
+    #[cfg(feature = "std")]
+    pub fn to_der(&self) -> Vec<u8> {
+        let mut der = [0u8; 16 + Seed::BYTES];
+        der[0..16].copy_from_slice(&DER_HEADER_SK);
+        der[16..].copy_from_slice(self.seed().as_ref());
+        der.to_vec()
+    }
+
+    /// Export a secret key as an OpenSSL-compatible PEM file.
+    #[cfg(feature = "std")]
+    pub fn to_pem(&self) -> String {
+        let b64 = Base64::encode_to_string(self.to_der()).unwrap();
+        format!(
+            "-----BEGIN PRIVATE KEY-----\n{}\n-----END PRIVATE KEY-----\n",
+            b64
+        )
+    }
+}
+
+impl PublicKey {
+    /// Import a public key from an OpenSSL-compatible DER file.
+    pub fn from_der(der: &[u8]) -> Result<Self, Error> {
+        if der.len() != DER_HEADER_PK.len() + PublicKey::BYTES || der[0..12] != DER_HEADER_PK {
+            return Err(Error::ParseError);
+        }
+        let mut pk = [0u8; PublicKey::BYTES];
+        pk.copy_from_slice(&der[12..]);
+        let pk = PublicKey::new(pk);
+        Ok(pk)
+    }
+
+    /// Import a public key from an OpenSSL-compatible PEM file.
+    pub fn from_pem(pem: &str) -> Result<Self, Error> {
+        let mut it = pem.split("-----BEGIN PUBLIC KEY-----");
+        let _ = it.next().ok_or(Error::ParseError)?;
+        let inner = it.next().ok_or(Error::ParseError)?;
+        let mut it = inner.split("-----END PUBLIC KEY-----");
+        let b64 = it.next().ok_or(Error::ParseError)?;
+        let _ = it.next().ok_or(Error::ParseError)?;
+        let mut der = [0u8; 12 + PublicKey::BYTES];
+        Base64::decode(&mut der, b64, Some(b"\r\n\t ")).map_err(|_| Error::ParseError)?;
+        Self::from_der(&der)
+    }
+
+    /// Export a public key as an OpenSSL-compatible DER file.
+    #[cfg(feature = "std")]
+    pub fn to_der(&self) -> Vec<u8> {
+        let mut der = [0u8; 12 + PublicKey::BYTES];
+        der[0..12].copy_from_slice(&DER_HEADER_PK);
+        der[12..].copy_from_slice(self.as_ref());
+        der.to_vec()
+    }
+
+    /// Export a public key as an OpenSSL-compatible PEM file.
+    #[cfg(feature = "std")]
+    pub fn to_pem(&self) -> String {
+        let b64 = Base64::encode_to_string(self.to_der()).unwrap();
+        format!(
+            "-----BEGIN PUBLIC KEY-----\n{}\n-----END PUBLIC KEY-----\n",
+            b64
+        )
+    }
+}
+
+#[test]
+fn test_pem() {
+    let sk_pem = "-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEIMXY1NUbUe/3dW2YUoKW5evsnCJPMfj60/q0RzGne3gg
+-----END PRIVATE KEY-----\n";
+    let sk = SecretKey::from_pem(sk_pem).unwrap();
+
+    let pk_pem = "-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEAyrRjJfTnhMcW5igzYvPirFW5eUgMdKeClGzQhd4qw+Y=
+-----END PUBLIC KEY-----\n";
+    let pk = PublicKey::from_pem(pk_pem).unwrap();
+
+    assert_eq!(sk.public_key(), pk);
+
+    #[cfg(features = "std")]
+    {
+        let sk_pem2 = sk.to_pem();
+        let pk_pem2 = pk.to_pem();
+        assert_eq!(sk_pem, sk_pem2);
+        assert_eq!(pk_pem, pk_pem2);
+    }
+}
+
+#[test]
+#[cfg(feature = "random")]
+fn test_der() {
+    let kp = KeyPair::generate();
+    let sk_der = kp.sk.to_der();
+    let sk2 = SecretKey::from_der(&sk_der).unwrap();
+    let pk_der = kp.pk.to_der();
+    let pk2 = PublicKey::from_der(&pk_der).unwrap();
+    assert_eq!(kp.sk, sk2);
+    assert_eq!(kp.pk, pk2);
+}
diff --git a/vendor/ed25519-compact/src/sha512.rs b/vendor/ed25519-compact/src/sha512.rs
new file mode 100644
index 0000000..66ab498
--- /dev/null
+++ b/vendor/ed25519-compact/src/sha512.rs
@@ -0,0 +1,378 @@
+//! A small, self-contained SHA512 implementation
+//! (C) Frank Denis, public domain
+
+#![allow(
+    non_snake_case,
+    clippy::cast_lossless,
+    clippy::eq_op,
+    clippy::identity_op,
+    clippy::many_single_char_names,
+    clippy::unreadable_literal
+)]
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline(always))]
+fn load_be(base: &[u8], offset: usize) -> u64 {
+    let addr = &base[offset..];
+    (addr[7] as u64)
+        | (addr[6] as u64) << 8
+        | (addr[5] as u64) << 16
+        | (addr[4] as u64) << 24
+        | (addr[3] as u64) << 32
+        | (addr[2] as u64) << 40
+        | (addr[1] as u64) << 48
+        | (addr[0] as u64) << 56
+}
+
+#[cfg_attr(feature = "opt_size", inline(never))]
+#[cfg_attr(not(feature = "opt_size"), inline(always))]
+fn store_be(base: &mut [u8], offset: usize, x: u64) {
+    let addr = &mut base[offset..];
+    addr[7] = x as u8;
+    addr[6] = (x >> 8) as u8;
+    addr[5] = (x >> 16) as u8;
+    addr[4] = (x >> 24) as u8;
+    addr[3] = (x >> 32) as u8;
+    addr[2] = (x >> 40) as u8;
+    addr[1] = (x >> 48) as u8;
+    addr[0] = (x >> 56) as u8;
+}
+
+struct W([u64; 16]);
+
+#[derive(Copy, Clone)]
+struct State([u64; 8]);
+
+impl W {
+    fn new(input: &[u8]) -> Self {
+        let mut w = [0u64; 16];
+        for (i, e) in w.iter_mut().enumerate() {
+            *e = load_be(input, i * 8)
+        }
+        W(w)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn Ch(x: u64, y: u64, z: u64) -> u64 {
+        (x & y) ^ (!x & z)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn Maj(x: u64, y: u64, z: u64) -> u64 {
+        (x & y) ^ (x & z) ^ (y & z)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn Sigma0(x: u64) -> u64 {
+        x.rotate_right(28) ^ x.rotate_right(34) ^ x.rotate_right(39)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn Sigma1(x: u64) -> u64 {
+        x.rotate_right(14) ^ x.rotate_right(18) ^ x.rotate_right(41)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn sigma0(x: u64) -> u64 {
+        x.rotate_right(1) ^ x.rotate_right(8) ^ (x >> 7)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn sigma1(x: u64) -> u64 {
+        x.rotate_right(19) ^ x.rotate_right(61) ^ (x >> 6)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn M(&mut self, a: usize, b: usize, c: usize, d: usize) {
+        let w = &mut self.0;
+        w[a] = w[a]
+            .wrapping_add(Self::sigma1(w[b]))
+            .wrapping_add(w[c])
+            .wrapping_add(Self::sigma0(w[d]));
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn expand(&mut self) {
+        self.M(0, (0 + 14) & 15, (0 + 9) & 15, (0 + 1) & 15);
+        self.M(1, (1 + 14) & 15, (1 + 9) & 15, (1 + 1) & 15);
+        self.M(2, (2 + 14) & 15, (2 + 9) & 15, (2 + 1) & 15);
+        self.M(3, (3 + 14) & 15, (3 + 9) & 15, (3 + 1) & 15);
+        self.M(4, (4 + 14) & 15, (4 + 9) & 15, (4 + 1) & 15);
+        self.M(5, (5 + 14) & 15, (5 + 9) & 15, (5 + 1) & 15);
+        self.M(6, (6 + 14) & 15, (6 + 9) & 15, (6 + 1) & 15);
+        self.M(7, (7 + 14) & 15, (7 + 9) & 15, (7 + 1) & 15);
+        self.M(8, (8 + 14) & 15, (8 + 9) & 15, (8 + 1) & 15);
+        self.M(9, (9 + 14) & 15, (9 + 9) & 15, (9 + 1) & 15);
+        self.M(10, (10 + 14) & 15, (10 + 9) & 15, (10 + 1) & 15);
+        self.M(11, (11 + 14) & 15, (11 + 9) & 15, (11 + 1) & 15);
+        self.M(12, (12 + 14) & 15, (12 + 9) & 15, (12 + 1) & 15);
+        self.M(13, (13 + 14) & 15, (13 + 9) & 15, (13 + 1) & 15);
+        self.M(14, (14 + 14) & 15, (14 + 9) & 15, (14 + 1) & 15);
+        self.M(15, (15 + 14) & 15, (15 + 9) & 15, (15 + 1) & 15);
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn F(&mut self, state: &mut State, i: usize, k: u64) {
+        let t = &mut state.0;
+        t[(16 - i + 7) & 7] = t[(16 - i + 7) & 7]
+            .wrapping_add(Self::Sigma1(t[(16 - i + 4) & 7]))
+            .wrapping_add(Self::Ch(
+                t[(16 - i + 4) & 7],
+                t[(16 - i + 5) & 7],
+                t[(16 - i + 6) & 7],
+            ))
+            .wrapping_add(k)
+            .wrapping_add(self.0[i]);
+        t[(16 - i + 3) & 7] = t[(16 - i + 3) & 7].wrapping_add(t[(16 - i + 7) & 7]);
+        t[(16 - i + 7) & 7] = t[(16 - i + 7) & 7]
+            .wrapping_add(Self::Sigma0(t[(16 - i + 0) & 7]))
+            .wrapping_add(Self::Maj(
+                t[(16 - i + 0) & 7],
+                t[(16 - i + 1) & 7],
+                t[(16 - i + 2) & 7],
+            ));
+    }
+
+    fn G(&mut self, state: &mut State, s: usize) {
+        const ROUND_CONSTANTS: [u64; 80] = [
+            0x428a2f98d728ae22,
+            0x7137449123ef65cd,
+            0xb5c0fbcfec4d3b2f,
+            0xe9b5dba58189dbbc,
+            0x3956c25bf348b538,
+            0x59f111f1b605d019,
+            0x923f82a4af194f9b,
+            0xab1c5ed5da6d8118,
+            0xd807aa98a3030242,
+            0x12835b0145706fbe,
+            0x243185be4ee4b28c,
+            0x550c7dc3d5ffb4e2,
+            0x72be5d74f27b896f,
+            0x80deb1fe3b1696b1,
+            0x9bdc06a725c71235,
+            0xc19bf174cf692694,
+            0xe49b69c19ef14ad2,
+            0xefbe4786384f25e3,
+            0x0fc19dc68b8cd5b5,
+            0x240ca1cc77ac9c65,
+            0x2de92c6f592b0275,
+            0x4a7484aa6ea6e483,
+            0x5cb0a9dcbd41fbd4,
+            0x76f988da831153b5,
+            0x983e5152ee66dfab,
+            0xa831c66d2db43210,
+            0xb00327c898fb213f,
+            0xbf597fc7beef0ee4,
+            0xc6e00bf33da88fc2,
+            0xd5a79147930aa725,
+            0x06ca6351e003826f,
+            0x142929670a0e6e70,
+            0x27b70a8546d22ffc,
+            0x2e1b21385c26c926,
+            0x4d2c6dfc5ac42aed,
+            0x53380d139d95b3df,
+            0x650a73548baf63de,
+            0x766a0abb3c77b2a8,
+            0x81c2c92e47edaee6,
+            0x92722c851482353b,
+            0xa2bfe8a14cf10364,
+            0xa81a664bbc423001,
+            0xc24b8b70d0f89791,
+            0xc76c51a30654be30,
+            0xd192e819d6ef5218,
+            0xd69906245565a910,
+            0xf40e35855771202a,
+            0x106aa07032bbd1b8,
+            0x19a4c116b8d2d0c8,
+            0x1e376c085141ab53,
+            0x2748774cdf8eeb99,
+            0x34b0bcb5e19b48a8,
+            0x391c0cb3c5c95a63,
+            0x4ed8aa4ae3418acb,
+            0x5b9cca4f7763e373,
+            0x682e6ff3d6b2b8a3,
+            0x748f82ee5defb2fc,
+            0x78a5636f43172f60,
+            0x84c87814a1f0ab72,
+            0x8cc702081a6439ec,
+            0x90befffa23631e28,
+            0xa4506cebde82bde9,
+            0xbef9a3f7b2c67915,
+            0xc67178f2e372532b,
+            0xca273eceea26619c,
+            0xd186b8c721c0c207,
+            0xeada7dd6cde0eb1e,
+            0xf57d4f7fee6ed178,
+            0x06f067aa72176fba,
+            0x0a637dc5a2c898a6,
+            0x113f9804bef90dae,
+            0x1b710b35131c471b,
+            0x28db77f523047d84,
+            0x32caab7b40c72493,
+            0x3c9ebe0a15c9bebc,
+            0x431d67c49c100d4c,
+            0x4cc5d4becb3e42b6,
+            0x597f299cfc657e2a,
+            0x5fcb6fab3ad6faec,
+            0x6c44198c4a475817,
+        ];
+        let rc = &ROUND_CONSTANTS[s * 16..];
+        self.F(state, 0, rc[0]);
+        self.F(state, 1, rc[1]);
+        self.F(state, 2, rc[2]);
+        self.F(state, 3, rc[3]);
+        self.F(state, 4, rc[4]);
+        self.F(state, 5, rc[5]);
+        self.F(state, 6, rc[6]);
+        self.F(state, 7, rc[7]);
+        self.F(state, 8, rc[8]);
+        self.F(state, 9, rc[9]);
+        self.F(state, 10, rc[10]);
+        self.F(state, 11, rc[11]);
+        self.F(state, 12, rc[12]);
+        self.F(state, 13, rc[13]);
+        self.F(state, 14, rc[14]);
+        self.F(state, 15, rc[15]);
+    }
+}
+
+impl State {
+    fn new() -> Self {
+        const IV: [u8; 64] = [
+            0x6a, 0x09, 0xe6, 0x67, 0xf3, 0xbc, 0xc9, 0x08, 0xbb, 0x67, 0xae, 0x85, 0x84, 0xca,
+            0xa7, 0x3b, 0x3c, 0x6e, 0xf3, 0x72, 0xfe, 0x94, 0xf8, 0x2b, 0xa5, 0x4f, 0xf5, 0x3a,
+            0x5f, 0x1d, 0x36, 0xf1, 0x51, 0x0e, 0x52, 0x7f, 0xad, 0xe6, 0x82, 0xd1, 0x9b, 0x05,
+            0x68, 0x8c, 0x2b, 0x3e, 0x6c, 0x1f, 0x1f, 0x83, 0xd9, 0xab, 0xfb, 0x41, 0xbd, 0x6b,
+            0x5b, 0xe0, 0xcd, 0x19, 0x13, 0x7e, 0x21, 0x79,
+        ];
+        let mut t = [0u64; 8];
+        for (i, e) in t.iter_mut().enumerate() {
+            *e = load_be(&IV, i * 8)
+        }
+        State(t)
+    }
+
+    #[cfg_attr(feature = "opt_size", inline(never))]
+    #[cfg_attr(not(feature = "opt_size"), inline(always))]
+    fn add(&mut self, x: &State) {
+        let sx = &mut self.0;
+        let ex = &x.0;
+        sx[0] = sx[0].wrapping_add(ex[0]);
+        sx[1] = sx[1].wrapping_add(ex[1]);
+        sx[2] = sx[2].wrapping_add(ex[2]);
+        sx[3] = sx[3].wrapping_add(ex[3]);
+        sx[4] = sx[4].wrapping_add(ex[4]);
+        sx[5] = sx[5].wrapping_add(ex[5]);
+        sx[6] = sx[6].wrapping_add(ex[6]);
+        sx[7] = sx[7].wrapping_add(ex[7]);
+    }
+
+    fn store(&self, out: &mut [u8]) {
+        for (i, &e) in self.0.iter().enumerate() {
+            store_be(out, i * 8, e);
+        }
+    }
+
+    fn blocks(&mut self, mut input: &[u8]) -> usize {
+        let mut t = *self;
+        let mut inlen = input.len();
+        while inlen >= 128 {
+            let mut w = W::new(input);
+            w.G(&mut t, 0);
+            w.expand();
+            w.G(&mut t, 1);
+            w.expand();
+            w.G(&mut t, 2);
+            w.expand();
+            w.G(&mut t, 3);
+            w.expand();
+            w.G(&mut t, 4);
+            t.add(self);
+            self.0 = t.0;
+            input = &input[128..];
+            inlen -= 128;
+        }
+        inlen
+    }
+}
+
+#[derive(Copy, Clone)]
+pub struct Hash {
+    state: State,
+    w: [u8; 128],
+    r: usize,
+    len: usize,
+}
+
+impl Hash {
+    pub fn new() -> Hash {
+        Hash {
+            state: State::new(),
+            r: 0,
+            w: [0u8; 128],
+            len: 0,
+        }
+    }
+
+    /// Absorb content
+    pub fn update<T: AsRef<[u8]>>(&mut self, input: T) {
+        let input = input.as_ref();
+        let mut n = input.len();
+        self.len += n;
+        let av = 128 - self.r;
+        let tc = ::core::cmp::min(n, av);
+        self.w[self.r..self.r + tc].copy_from_slice(&input[0..tc]);
+        self.r += tc;
+        n -= tc;
+        let pos = tc;
+        if self.r == 128 {
+            self.state.blocks(&self.w);
+            self.r = 0;
+        }
+        if self.r == 0 && n > 0 {
+            let rb = self.state.blocks(&input[pos..]);
+            if rb > 0 {
+                self.w[..rb].copy_from_slice(&input[pos + n - rb..]);
+                self.r = rb;
+            }
+        }
+    }
+
+    /// Compute SHA512(absorbed content)
+    pub fn finalize(mut self) -> [u8; 64] {
+        let mut padded = [0u8; 256];
+        padded[..self.r].copy_from_slice(&self.w[..self.r]);
+        padded[self.r] = 0x80;
+        let r = if self.r < 112 { 128 } else { 256 };
+        let bits = self.len * 8;
+        for i in 0..8 {
+            padded[r - 8 + i] = (bits as u64 >> (56 - i * 8)) as u8;
+        }
+        self.state.blocks(&padded[..r]);
+        let mut out = [0u8; 64];
+        self.state.store(&mut out);
+        out
+    }
+
+    /// Compute SHA512(`input`)
+    pub fn hash<T: AsRef<[u8]>>(input: T) -> [u8; 64] {
+        let mut h = Hash::new();
+        h.update(input);
+        h.finalize()
+    }
+}
+
+impl Default for Hash {
+    fn default() -> Self {
+        Self::new()
+    }
+}
diff --git a/vendor/ed25519-compact/src/x25519.rs b/vendor/ed25519-compact/src/x25519.rs
new file mode 100644
index 0000000..9297d06
--- /dev/null
+++ b/vendor/ed25519-compact/src/x25519.rs
@@ -0,0 +1,361 @@
+use core::ops::{Deref, DerefMut};
+
+use super::common::*;
+use super::error::Error;
+use super::field25519::*;
+
+const POINT_BYTES: usize = 32;
+
+/// Non-uniform output of a scalar multiplication.
+/// This represents a point on the curve, and should not be used directly as a
+/// cipher key.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct DHOutput([u8; DHOutput::BYTES]);
+
+impl DHOutput {
+    pub const BYTES: usize = 32;
+}
+
+impl Deref for DHOutput {
+    type Target = [u8; DHOutput::BYTES];
+
+    /// Returns the output of the scalar multiplication as bytes.
+    /// The output is not uniform, and should be hashed before use.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for DHOutput {
+    /// Returns the output of the scalar multiplication as bytes.
+    /// The output is not uniform, and should be hashed before use.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl From<DHOutput> for PublicKey {
+    fn from(dh: DHOutput) -> Self {
+        PublicKey(dh.0)
+    }
+}
+
+impl From<DHOutput> for SecretKey {
+    fn from(dh: DHOutput) -> Self {
+        SecretKey(dh.0)
+    }
+}
+
+impl Drop for DHOutput {
+    fn drop(&mut self) {
+        Mem::wipe(self.0)
+    }
+}
+
+/// A public key.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct PublicKey([u8; POINT_BYTES]);
+
+impl PublicKey {
+    /// Number of raw bytes in a public key.
+    pub const BYTES: usize = POINT_BYTES;
+
+    /// Creates a public key from raw bytes.
+    pub fn new(pk: [u8; PublicKey::BYTES]) -> Self {
+        PublicKey(pk)
+    }
+
+    /// Creates a public key from a slice.
+    pub fn from_slice(pk: &[u8]) -> Result<Self, Error> {
+        let mut pk_ = [0u8; PublicKey::BYTES];
+        if pk.len() != pk_.len() {
+            return Err(Error::InvalidPublicKey);
+        }
+        Fe::reject_noncanonical(pk)?;
+        pk_.copy_from_slice(pk);
+        Ok(PublicKey::new(pk_))
+    }
+
+    /// Multiply a point by the cofactor, returning an error if the element is
+    /// in a small-order group.
+    pub fn clear_cofactor(&self) -> Result<[u8; PublicKey::BYTES], Error> {
+        let cofactor = [
+            8u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0,
+        ];
+        self.ladder(&cofactor, 4)
+    }
+
+    /// Multiply the point represented by the public key by the scalar after
+    /// clamping it
+    pub fn dh(&self, sk: &SecretKey) -> Result<DHOutput, Error> {
+        let sk = sk.clamped();
+        Ok(DHOutput(self.ladder(&sk.0, 255)?))
+    }
+
+    /// Multiply the point represented by the public key by the scalar WITHOUT
+    /// CLAMPING
+    pub fn unclamped_mul(&self, sk: &SecretKey) -> Result<DHOutput, Error> {
+        self.clear_cofactor()?;
+        Ok(DHOutput(self.ladder(&sk.0, 256)?))
+    }
+
+    fn ladder(&self, s: &[u8], bits: usize) -> Result<[u8; POINT_BYTES], Error> {
+        let x1 = Fe::from_bytes(&self.0);
+        let mut x2 = FE_ONE;
+        let mut z2 = FE_ZERO;
+        let mut x3 = x1;
+        let mut z3 = FE_ONE;
+        let mut swap: u8 = 0;
+        let mut pos = bits - 1;
+        loop {
+            let bit = (s[pos >> 3] >> (pos & 7)) & 1;
+            swap ^= bit;
+            Fe::cswap2(&mut x2, &mut x3, &mut z2, &mut z3, swap);
+            swap = bit;
+            let a = x2 + z2;
+            let b = x2 - z2;
+            let aa = a.square();
+            let bb = b.square();
+            x2 = aa * bb;
+            let e = aa - bb;
+            let da = (x3 - z3) * a;
+            let cb = (x3 + z3) * b;
+            x3 = (da + cb).square();
+            z3 = x1 * ((da - cb).square());
+            z2 = e * (bb + (e.mul32(121666)));
+            if pos == 0 {
+                break;
+            }
+            pos -= 1;
+        }
+        Fe::cswap2(&mut x2, &mut x3, &mut z2, &mut z3, swap);
+        z2 = z2.invert();
+        x2 = x2 * z2;
+        if x2.is_zero() {
+            return Err(Error::WeakPublicKey);
+        }
+        Ok(x2.to_bytes())
+    }
+
+    /// The Curve25519 base point
+    #[inline]
+    pub fn base_point() -> PublicKey {
+        PublicKey(FE_CURVE25519_BASEPOINT.to_bytes())
+    }
+}
+
+impl Deref for PublicKey {
+    type Target = [u8; PublicKey::BYTES];
+
+    /// Returns a public key as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for PublicKey {
+    /// Returns a public key as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+/// A secret key.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct SecretKey([u8; SecretKey::BYTES]);
+
+impl SecretKey {
+    /// Number of bytes in a secret key.
+    pub const BYTES: usize = 32;
+
+    /// Creates a secret key from raw bytes.
+    pub fn new(sk: [u8; SecretKey::BYTES]) -> Self {
+        SecretKey(sk)
+    }
+
+    /// Creates a secret key from a slice.
+    pub fn from_slice(sk: &[u8]) -> Result<Self, Error> {
+        let mut sk_ = [0u8; SecretKey::BYTES];
+        if sk.len() != sk_.len() {
+            return Err(Error::InvalidSecretKey);
+        }
+        sk_.copy_from_slice(sk);
+        Ok(SecretKey::new(sk_))
+    }
+
+    /// Perform the X25519 clamping magic
+    pub fn clamped(&self) -> SecretKey {
+        let mut clamped = self.clone();
+        clamped[0] &= 248;
+        clamped[31] &= 63;
+        clamped[31] |= 64;
+        clamped
+    }
+
+    /// Recover the public key
+    pub fn recover_public_key(&self) -> Result<PublicKey, Error> {
+        let sk = self.clamped();
+        Ok(PublicKey(PublicKey::base_point().ladder(&sk.0, 255)?))
+    }
+
+    /// Returns `Ok(())` if the given public key is the public counterpart of
+    /// this secret key.
+    /// Returns `Err(Error::InvalidPublicKey)` otherwise.
+    pub fn validate_public_key(&self, pk: &PublicKey) -> Result<(), Error> {
+        let recovered_pk = self.recover_public_key()?;
+        if recovered_pk != *pk {
+            return Err(Error::InvalidPublicKey);
+        }
+        Ok(())
+    }
+}
+
+impl Drop for SecretKey {
+    fn drop(&mut self) {
+        Mem::wipe(self.0)
+    }
+}
+
+impl Deref for SecretKey {
+    type Target = [u8; SecretKey::BYTES];
+
+    /// Returns a secret key as bytes.
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for SecretKey {
+    /// Returns a secret key as mutable bytes.
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+/// A key pair.
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct KeyPair {
+    /// Public key part of the key pair.
+    pub pk: PublicKey,
+    /// Secret key part of the key pair.
+    pub sk: SecretKey,
+}
+
+impl KeyPair {
+    /// Generates a new key pair.
+    #[cfg(feature = "random")]
+    pub fn generate() -> KeyPair {
+        let mut sk = [0u8; SecretKey::BYTES];
+        getrandom::getrandom(&mut sk).expect("getrandom");
+        if Fe::from_bytes(&sk).is_zero() {
+            panic!("All-zero secret key");
+        }
+        let sk = SecretKey(sk);
+        let pk = sk
+            .recover_public_key()
+            .expect("generated public key is weak");
+        KeyPair { pk, sk }
+    }
+
+    /// Check that the public key is valid for the secret key.
+    pub fn validate(&self) -> Result<(), Error> {
+        self.sk.validate_public_key(&self.pk)
+    }
+}
+
+#[cfg(not(feature = "disable-signatures"))]
+mod from_ed25519 {
+    use super::super::{
+        edwards25519, sha512, KeyPair as EdKeyPair, PublicKey as EdPublicKey,
+        SecretKey as EdSecretKey,
+    };
+    use super::*;
+
+    impl SecretKey {
+        /// Convert an Ed25519 secret key to a X25519 secret key.
+        pub fn from_ed25519(edsk: &EdSecretKey) -> Result<SecretKey, Error> {
+            let seed = edsk.seed();
+            let az: [u8; 64] = {
+                let mut hash_output = sha512::Hash::hash(*seed);
+                hash_output[0] &= 248;
+                hash_output[31] &= 63;
+                hash_output[31] |= 64;
+                hash_output
+            };
+            SecretKey::from_slice(&az[..32])
+        }
+    }
+
+    impl PublicKey {
+        /// Convert an Ed25519 public key to a X25519 public key.
+        pub fn from_ed25519(edpk: &EdPublicKey) -> Result<PublicKey, Error> {
+            let pk = PublicKey::from_slice(
+                &edwards25519::ge_to_x25519_vartime(edpk).ok_or(Error::InvalidPublicKey)?,
+            )?;
+            pk.clear_cofactor()?;
+            Ok(pk)
+        }
+    }
+
+    impl KeyPair {
+        /// Convert an Ed25519 key pair to a X25519 key pair.
+        pub fn from_ed25519(edkp: &EdKeyPair) -> Result<KeyPair, Error> {
+            let pk = PublicKey::from_ed25519(&edkp.pk)?;
+            let sk = SecretKey::from_ed25519(&edkp.sk)?;
+            Ok(KeyPair { pk, sk })
+        }
+    }
+}
+
+#[cfg(not(feature = "disable-signatures"))]
+pub use from_ed25519::*;
+
+#[test]
+#[cfg(feature = "random")]
+fn test_x25519() {
+    let sk_1 = SecretKey::from_slice(&[
+        1u8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0,
+    ])
+    .unwrap();
+    let output = PublicKey::base_point().unclamped_mul(&sk_1).unwrap();
+    assert_eq!(PublicKey::from(output), PublicKey::base_point());
+    let kp_a = KeyPair::generate();
+    let kp_b = KeyPair::generate();
+    let output_a = kp_b.pk.dh(&kp_a.sk).unwrap();
+    let output_b = kp_a.pk.dh(&kp_b.sk).unwrap();
+    assert_eq!(output_a, output_b);
+}
+
+#[test]
+#[cfg(all(not(feature = "disable-signatures"), feature = "random"))]
+fn test_x25519_map() {
+    use super::KeyPair as EdKeyPair;
+    let edkp_a = EdKeyPair::generate();
+    let edkp_b = EdKeyPair::generate();
+    let kp_a = KeyPair::from_ed25519(&edkp_a).unwrap();
+    let kp_b = KeyPair::from_ed25519(&edkp_b).unwrap();
+    let output_a = kp_b.pk.dh(&kp_a.sk).unwrap();
+    let output_b = kp_a.pk.dh(&kp_b.sk).unwrap();
+    assert_eq!(output_a, output_b);
+}
+
+#[test]
+#[cfg(all(not(feature = "disable-signatures"), feature = "random"))]
+fn test_x25519_invalid_keypair() {
+    let kp1 = KeyPair::generate();
+    let kp2 = KeyPair::generate();
+
+    assert_eq!(
+        kp1.sk.validate_public_key(&kp2.pk).unwrap_err(),
+        Error::InvalidPublicKey
+    );
+    assert_eq!(
+        kp2.sk.validate_public_key(&kp1.pk).unwrap_err(),
+        Error::InvalidPublicKey
+    );
+    assert!(kp1.sk.validate_public_key(&kp1.pk).is_ok());
+    assert!(kp2.sk.validate_public_key(&kp2.pk).is_ok());
+    assert!(kp1.validate().is_ok());
+}