1 files changed, 189 insertions, 0 deletions
diff --git a/vendor/crypto-bigint/src/limb.rs b/vendor/crypto-bigint/src/limb.rs
new file mode 100644
index 000000000..df3ae7a72
--- /dev/null
+++ b/vendor/crypto-bigint/src/limb.rs
@@ -0,0 +1,189 @@
+//! Big integers are represented as an array of smaller CPU word-size integers
+//! called "limbs".
+
+#![allow(clippy::derive_hash_xor_eq)]
+
+mod add;
+mod bit_and;
+mod bit_not;
+mod bit_or;
+mod bit_xor;
+mod bits;
+mod cmp;
+mod encoding;
+mod from;
+mod mul;
+mod shl;
+mod shr;
+mod sub;
+
+#[cfg(feature = "rand_core")]
+mod rand;
+
+use crate::Zero;
+use core::fmt;
+use subtle::{Choice, ConditionallySelectable};
+
+#[cfg(feature = "serde")]
+use serdect::serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
+compile_error!("this crate builds on 32-bit and 64-bit platforms only");
+
+//
+// 32-bit definitions
+//
+
+/// Inner integer type that the [`Limb`] newtype wraps.
+#[cfg(target_pointer_width = "32")]
+pub type Word = u32;
+
+/// Signed integer type that corresponds to [`Word`].
+#[cfg(target_pointer_width = "32")]
+pub(crate) type SignedWord = i32;
+
+/// Unsigned wide integer type: double the width of [`Word`].
+#[cfg(target_pointer_width = "32")]
+pub type WideWord = u64;
+
+/// Signed wide integer type: double the width of [`Limb`].
+#[cfg(target_pointer_width = "32")]
+pub(crate) type WideSignedWord = i64;
+
+//
+// 64-bit definitions
+//
+
+/// Unsigned integer type that the [`Limb`] newtype wraps.
+#[cfg(target_pointer_width = "64")]
+pub type Word = u64;
+
+/// Signed integer type that corresponds to [`Word`].
+#[cfg(target_pointer_width = "64")]
+pub(crate) type SignedWord = i64;
+
+/// Wide integer type: double the width of [`Word`].
+#[cfg(target_pointer_width = "64")]
+pub type WideWord = u128;
+
+/// Signed wide integer type: double the width of [`SignedWord`].
+#[cfg(target_pointer_width = "64")]
+pub(crate) type WideSignedWord = i128;
+
+//
+// Deprecated legacy names
+//
+
+// TODO(tarcieri): remove these in the next breaking release
+
+/// Deprecated: unsigned integer type that the [`Limb`] newtype wraps.
+#[deprecated(since = "0.4.8", note = "please use `Word` instead")]
+pub type LimbUInt = Word;
+
+/// Deprecated: wide integer type which is double the width of [`Word`].
+#[deprecated(since = "0.4.8", note = "please use `WideWord` instead")]
+pub type WideLimbUInt = WideWord;
+
+/// Highest bit in a [`Limb`].
+pub(crate) const HI_BIT: usize = Limb::BIT_SIZE - 1;
+
+/// Big integers are represented as an array of smaller CPU word-size integers
+/// called "limbs".
+#[derive(Copy, Clone, Debug, Default, Hash)]
+#[repr(transparent)]
+pub struct Limb(pub Word);
+
+impl Limb {
+    /// The value `0`.
+    pub const ZERO: Self = Limb(0);
+
+    /// The value `1`.
+    pub const ONE: Self = Limb(1);
+
+    /// Maximum value this [`Limb`] can express.
+    pub const MAX: Self = Limb(Word::MAX);
+
+    // 32-bit
+
+    /// Size of the inner integer in bits.
+    #[cfg(target_pointer_width = "32")]
+    pub const BIT_SIZE: usize = 32;
+    /// Size of the inner integer in bytes.
+    #[cfg(target_pointer_width = "32")]
+    pub const BYTE_SIZE: usize = 4;
+
+    // 64-bit
+
+    /// Size of the inner integer in bits.
+    #[cfg(target_pointer_width = "64")]
+    pub const BIT_SIZE: usize = 64;
+    /// Size of the inner integer in bytes.
+    #[cfg(target_pointer_width = "64")]
+    pub const BYTE_SIZE: usize = 8;
+
+    /// Return `a` if `c`==0 or `b` if `c`==`Word::MAX`.
+    ///
+    /// Const-friendly: we can't yet use `subtle` in `const fn` contexts.
+    #[inline]
+    pub(crate) const fn ct_select(a: Self, b: Self, c: Word) -> Self {
+        Self(a.0 ^ (c & (a.0 ^ b.0)))
+    }
+}
+
+impl ConditionallySelectable for Limb {
+    #[inline]
+    fn conditional_select(a: &Self, b: &Self, choice: Choice) -> Self {
+        Self(Word::conditional_select(&a.0, &b.0, choice))
+    }
+}
+
+impl Zero for Limb {
+    const ZERO: Self = Self::ZERO;
+}
+
+impl fmt::Display for Limb {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::UpperHex::fmt(self, f)
+    }
+}
+
+impl fmt::LowerHex for Limb {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:0width$x}", &self.0, width = Self::BYTE_SIZE * 2)
+    }
+}
+
+impl fmt::UpperHex for Limb {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:0width$X}", &self.0, width = Self::BYTE_SIZE * 2)
+    }
+}
+
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+impl<'de> Deserialize<'de> for Limb {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        Ok(Self(Word::deserialize(deserializer)?))
+    }
+}
+
+#[cfg(feature = "serde")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
+impl<'de> Serialize for Limb {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.0.serialize(serializer)
+    }
+}
+
+#[cfg(feature = "zeroize")]
+#[cfg_attr(docsrs, doc(cfg(feature = "zeroize")))]
+impl zeroize::DefaultIsZeroes for Limb {}