2 files changed, 109 insertions, 0 deletions
diff --git a/vendor/crypto-bigint/src/boxed/uint/add.rs b/vendor/crypto-bigint/src/boxed/uint/add.rs
new file mode 100644
index 000000000..b6cedc78f
--- /dev/null
+++ b/vendor/crypto-bigint/src/boxed/uint/add.rs
@@ -0,0 +1,62 @@
+//! [`BoxedUint`] addition operations.
+
+use crate::{BoxedUint, CheckedAdd, Limb, Zero};
+use subtle::CtOption;
+
+impl BoxedUint {
+    /// Computes `a + b + carry`, returning the result along with the new carry.
+    #[inline(always)]
+    pub fn adc(&self, rhs: &Self, carry: Limb) -> (Self, Limb) {
+        Self::chain(self, rhs, carry, |a, b, c| a.adc(b, c))
+    }
+
+    /// Perform wrapping addition, discarding overflow.
+    pub fn wrapping_add(&self, rhs: &Self) -> Self {
+        self.adc(rhs, Limb::ZERO).0
+    }
+}
+
+impl CheckedAdd<&BoxedUint> for BoxedUint {
+    type Output = Self;
+
+    fn checked_add(&self, rhs: &Self) -> CtOption<Self> {
+        let (result, carry) = self.adc(rhs, Limb::ZERO);
+        CtOption::new(result, carry.is_zero())
+    }
+}
+
+#[cfg(test)]
+#[allow(clippy::unwrap_used)]
+mod tests {
+    use super::{BoxedUint, CheckedAdd, Limb};
+
+    #[test]
+    fn adc_no_carry() {
+        let (res, carry) = BoxedUint::zero().adc(&BoxedUint::one(), Limb::ZERO);
+        assert_eq!(res, BoxedUint::one());
+        assert_eq!(carry, Limb::ZERO);
+    }
+
+    #[test]
+    fn adc_with_carry() {
+        let (res, carry) = BoxedUint::max(Limb::BITS)
+            .unwrap()
+            .adc(&BoxedUint::one(), Limb::ZERO);
+        assert_eq!(res, BoxedUint::zero());
+        assert_eq!(carry, Limb::ONE);
+    }
+
+    #[test]
+    fn checked_add_ok() {
+        let result = BoxedUint::zero().checked_add(&BoxedUint::one());
+        assert_eq!(result.unwrap(), BoxedUint::one());
+    }
+
+    #[test]
+    fn checked_add_overflow() {
+        let result = BoxedUint::max(Limb::BITS)
+            .unwrap()
+            .checked_add(&BoxedUint::one());
+        assert!(!bool::from(result.is_some()));
+    }
+}
diff --git a/vendor/crypto-bigint/src/boxed/uint/cmp.rs b/vendor/crypto-bigint/src/boxed/uint/cmp.rs
new file mode 100644
index 000000000..d850fc7d4
--- /dev/null
+++ b/vendor/crypto-bigint/src/boxed/uint/cmp.rs
@@ -0,0 +1,47 @@
+//! [`BoxedUint`] comparisons.
+//!
+//! By default these are all constant-time and use the `subtle` crate.
+
+use super::BoxedUint;
+use crate::Limb;
+use subtle::{Choice, ConstantTimeEq};
+
+impl ConstantTimeEq for BoxedUint {
+    #[inline]
+    fn ct_eq(&self, other: &Self) -> Choice {
+        let (shorter, longer) = Self::sort_by_precision(self, other);
+        let mut ret = Choice::from(1u8);
+
+        for i in 0..longer.limbs.len() {
+            let a = shorter.limbs.get(i).unwrap_or(&Limb::ZERO);
+            let b = longer.limbs.get(i).unwrap_or(&Limb::ZERO);
+            ret &= a.ct_eq(b);
+        }
+
+        ret
+    }
+}
+
+impl Eq for BoxedUint {}
+impl PartialEq for BoxedUint {
+    fn eq(&self, other: &Self) -> bool {
+        self.ct_eq(other).into()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::BoxedUint;
+    use subtle::ConstantTimeEq;
+
+    #[test]
+    fn ct_eq() {
+        let a = BoxedUint::zero();
+        let b = BoxedUint::one();
+
+        assert!(bool::from(a.ct_eq(&a)));
+        assert!(!bool::from(a.ct_eq(&b)));
+        assert!(!bool::from(b.ct_eq(&a)));
+        assert!(bool::from(b.ct_eq(&b)));
+    }
+}