1 files changed, 301 insertions, 0 deletions
diff --git a/third_party/rust/digest/src/lib.rs b/third_party/rust/digest/src/lib.rs
new file mode 100644
index 0000000000..fc82e2e3ad
--- /dev/null
+++ b/third_party/rust/digest/src/lib.rs
@@ -0,0 +1,301 @@
+//! This crate provides traits which describe functionality of cryptographic hash
+//! functions and Message Authentication algorithms.
+//!
+//! Traits in this repository are organized into the following levels:
+//!
+//! - **High-level convenience traits**: [`Digest`], [`DynDigest`], [`Mac`].
+//!   Wrappers around lower-level traits for most common use-cases. Users should
+//!   usually prefer using these traits.
+//! - **Mid-level traits**: [`Update`], [`FixedOutput`], [`FixedOutputReset`],
+//!   [`ExtendableOutput`], [`ExtendableOutputReset`], [`XofReader`],
+//!   [`VariableOutput`], [`Reset`], [`KeyInit`], and [`InnerInit`]. These
+//!   traits atomically describe available functionality of an algorithm.
+//! - **Marker traits**: [`HashMarker`], [`MacMarker`]. Used to distinguish
+//!   different algorithm classes.
+//! - **Low-level traits** defined in the [`core_api`] module. These traits
+//!   operate at a block-level and do not contain any built-in buffering.
+//!   They are intended to be implemented by low-level algorithm providers only.
+//!   Usually they should not be used in application-level code.
+//!
+//! Additionally hash functions implement traits from the standard library:
+//! [`Default`], [`Clone`], [`Write`][std::io::Write]. The latter is
+//! feature-gated behind `std` feature, which is usually enabled by default
+//! by hash implementation crates.
+
+#![no_std]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![forbid(unsafe_code)]
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg",
+    html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/media/6ee8e381/logo.svg"
+)]
+#![warn(missing_docs, rust_2018_idioms)]
+
+#[cfg(feature = "alloc")]
+#[macro_use]
+extern crate alloc;
+
+#[cfg(feature = "std")]
+extern crate std;
+
+#[cfg(feature = "rand_core")]
+#[cfg_attr(docsrs, doc(cfg(feature = "rand_core")))]
+pub use crypto_common::rand_core;
+
+#[cfg(feature = "alloc")]
+use alloc::boxed::Box;
+
+#[cfg(feature = "dev")]
+#[cfg_attr(docsrs, doc(cfg(feature = "dev")))]
+pub mod dev;
+
+#[cfg(feature = "core-api")]
+#[cfg_attr(docsrs, doc(cfg(feature = "core-api")))]
+pub mod core_api;
+mod digest;
+#[cfg(feature = "mac")]
+mod mac;
+
+#[cfg(feature = "core-api")]
+#[cfg_attr(docsrs, doc(cfg(feature = "core-api")))]
+pub use block_buffer;
+#[cfg(feature = "oid")]
+#[cfg_attr(docsrs, doc(cfg(feature = "oid")))]
+pub use const_oid;
+pub use crypto_common;
+
+pub use crate::digest::{Digest, DynDigest, HashMarker};
+pub use crypto_common::{generic_array, typenum, typenum::consts, Output, OutputSizeUser, Reset};
+#[cfg(feature = "mac")]
+pub use crypto_common::{InnerInit, InvalidLength, Key, KeyInit};
+#[cfg(feature = "mac")]
+pub use mac::{CtOutput, Mac, MacError, MacMarker};
+
+use core::fmt;
+
+/// Types which consume data with byte granularity.
+pub trait Update {
+    /// Update state using the provided data.
+    fn update(&mut self, data: &[u8]);
+
+    /// Digest input data in a chained manner.
+    #[must_use]
+    fn chain(mut self, data: impl AsRef<[u8]>) -> Self
+    where
+        Self: Sized,
+    {
+        self.update(data.as_ref());
+        self
+    }
+}
+
+/// Trait for hash functions with fixed-size output.
+pub trait FixedOutput: Update + OutputSizeUser + Sized {
+    /// Consume value and write result into provided array.
+    fn finalize_into(self, out: &mut Output<Self>);
+
+    /// Retrieve result and consume the hasher instance.
+    #[inline]
+    fn finalize_fixed(self) -> Output<Self> {
+        let mut out = Default::default();
+        self.finalize_into(&mut out);
+        out
+    }
+}
+
+/// Trait for hash functions with fixed-size output able to reset themselves.
+pub trait FixedOutputReset: FixedOutput + Reset {
+    /// Write result into provided array and reset the hasher state.
+    fn finalize_into_reset(&mut self, out: &mut Output<Self>);
+
+    /// Retrieve result and reset the hasher state.
+    #[inline]
+    fn finalize_fixed_reset(&mut self) -> Output<Self> {
+        let mut out = Default::default();
+        self.finalize_into_reset(&mut out);
+        out
+    }
+}
+
+/// Trait for reader types which are used to extract extendable output
+/// from a XOF (extendable-output function) result.
+pub trait XofReader {
+    /// Read output into the `buffer`. Can be called an unlimited number of times.
+    fn read(&mut self, buffer: &mut [u8]);
+
+    /// Read output into a boxed slice of the specified size.
+    ///
+    /// Can be called an unlimited number of times in combination with `read`.
+    ///
+    /// `Box<[u8]>` is used instead of `Vec<u8>` to save stack space, since
+    /// they have size of 2 and 3 words respectively.
+    #[cfg(feature = "alloc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+    fn read_boxed(&mut self, n: usize) -> Box<[u8]> {
+        let mut buf = vec![0u8; n].into_boxed_slice();
+        self.read(&mut buf);
+        buf
+    }
+}
+
+/// Trait for hash functions with extendable-output (XOF).
+pub trait ExtendableOutput: Sized + Update {
+    /// Reader
+    type Reader: XofReader;
+
+    /// Retrieve XOF reader and consume hasher instance.
+    fn finalize_xof(self) -> Self::Reader;
+
+    /// Finalize XOF and write result into `out`.
+    fn finalize_xof_into(self, out: &mut [u8]) {
+        self.finalize_xof().read(out);
+    }
+
+    /// Compute hash of `data` and write it into `output`.
+    fn digest_xof(input: impl AsRef<[u8]>, output: &mut [u8])
+    where
+        Self: Default,
+    {
+        let mut hasher = Self::default();
+        hasher.update(input.as_ref());
+        hasher.finalize_xof().read(output);
+    }
+
+    /// Retrieve result into a boxed slice of the specified size and consume
+    /// the hasher.
+    ///
+    /// `Box<[u8]>` is used instead of `Vec<u8>` to save stack space, since
+    /// they have size of 2 and 3 words respectively.
+    #[cfg(feature = "alloc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+    fn finalize_boxed(self, output_size: usize) -> Box<[u8]> {
+        let mut buf = vec![0u8; output_size].into_boxed_slice();
+        self.finalize_xof().read(&mut buf);
+        buf
+    }
+}
+
+/// Trait for hash functions with extendable-output (XOF) able to reset themselves.
+pub trait ExtendableOutputReset: ExtendableOutput + Reset {
+    /// Retrieve XOF reader and reset hasher instance state.
+    fn finalize_xof_reset(&mut self) -> Self::Reader;
+
+    /// Finalize XOF, write result into `out`, and reset the hasher state.
+    fn finalize_xof_reset_into(&mut self, out: &mut [u8]) {
+        self.finalize_xof_reset().read(out);
+    }
+
+    /// Retrieve result into a boxed slice of the specified size and reset
+    /// the hasher state.
+    ///
+    /// `Box<[u8]>` is used instead of `Vec<u8>` to save stack space, since
+    /// they have size of 2 and 3 words respectively.
+    #[cfg(feature = "alloc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+    fn finalize_boxed_reset(&mut self, output_size: usize) -> Box<[u8]> {
+        let mut buf = vec![0u8; output_size].into_boxed_slice();
+        self.finalize_xof_reset().read(&mut buf);
+        buf
+    }
+}
+
+/// Trait for hash functions with variable-size output.
+pub trait VariableOutput: Sized + Update {
+    /// Maximum size of output hash.
+    const MAX_OUTPUT_SIZE: usize;
+
+    /// Create new hasher instance with the given output size.
+    ///
+    /// It will return `Err(InvalidOutputSize)` in case if hasher can not return
+    /// hash of the specified output size.
+    fn new(output_size: usize) -> Result<Self, InvalidOutputSize>;
+
+    /// Get output size of the hasher instance provided to the `new` method
+    fn output_size(&self) -> usize;
+
+    /// Write result into the output buffer.
+    ///
+    /// Returns `Err(InvalidOutputSize)` if `out` size is not equal to
+    /// `self.output_size()`.
+    fn finalize_variable(self, out: &mut [u8]) -> Result<(), InvalidBufferSize>;
+
+    /// Compute hash of `data` and write it to `output`.
+    ///
+    /// Length of the output hash is determined by `output`. If `output` is
+    /// bigger than `Self::MAX_OUTPUT_SIZE`, this method returns
+    /// `InvalidOutputSize`.
+    fn digest_variable(
+        input: impl AsRef<[u8]>,
+        output: &mut [u8],
+    ) -> Result<(), InvalidOutputSize> {
+        let mut hasher = Self::new(output.len())?;
+        hasher.update(input.as_ref());
+        hasher
+            .finalize_variable(output)
+            .map_err(|_| InvalidOutputSize)
+    }
+
+    /// Retrieve result into a boxed slice and consume hasher.
+    ///
+    /// `Box<[u8]>` is used instead of `Vec<u8>` to save stack space, since
+    /// they have size of 2 and 3 words respectively.
+    #[cfg(feature = "alloc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+    fn finalize_boxed(self) -> Box<[u8]> {
+        let n = self.output_size();
+        let mut buf = vec![0u8; n].into_boxed_slice();
+        self.finalize_variable(&mut buf)
+            .expect("buf length is equal to output_size");
+        buf
+    }
+}
+
+/// Trait for hash functions with variable-size output able to reset themselves.
+pub trait VariableOutputReset: VariableOutput + Reset {
+    /// Write result into the output buffer and reset the hasher state.
+    ///
+    /// Returns `Err(InvalidOutputSize)` if `out` size is not equal to
+    /// `self.output_size()`.
+    fn finalize_variable_reset(&mut self, out: &mut [u8]) -> Result<(), InvalidBufferSize>;
+
+    /// Retrieve result into a boxed slice and reset the hasher state.
+    ///
+    /// `Box<[u8]>` is used instead of `Vec<u8>` to save stack space, since
+    /// they have size of 2 and 3 words respectively.
+    #[cfg(feature = "alloc")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "alloc")))]
+    fn finalize_boxed_reset(&mut self) -> Box<[u8]> {
+        let n = self.output_size();
+        let mut buf = vec![0u8; n].into_boxed_slice();
+        self.finalize_variable_reset(&mut buf)
+            .expect("buf length is equal to output_size");
+        buf
+    }
+}
+
+/// The error type used in variable hash traits.
+#[derive(Clone, Copy, Debug, Default)]
+pub struct InvalidOutputSize;
+
+impl fmt::Display for InvalidOutputSize {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("invalid output size")
+    }
+}
+
+#[cfg(feature = "std")]
+#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
+impl std::error::Error for InvalidOutputSize {}
+
+/// Buffer length is not equal to hash output size.
+#[derive(Default, Debug, Copy, Clone, Eq, PartialEq)]
+pub struct InvalidBufferSize;
+
+impl fmt::Display for InvalidBufferSize {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str("invalid buffer length")
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for InvalidBufferSize {}