1 files changed, 111 insertions, 0 deletions
diff --git a/rust/vendor/polyval/src/backend/autodetect.rs b/rust/vendor/polyval/src/backend/autodetect.rs
new file mode 100644
index 0000000..4d4ee97
--- /dev/null
+++ b/rust/vendor/polyval/src/backend/autodetect.rs
@@ -0,0 +1,111 @@
+//! Autodetection for CPU intrinsics, with fallback to the "soft" backend when
+//! they are unavailable.
+
+use crate::{backend::soft, Block, Key};
+use core::mem::ManuallyDrop;
+use universal_hash::{consts::U16, NewUniversalHash, Output, UniversalHash};
+
+#[cfg(all(target_arch = "aarch64", feature = "armv8"))]
+use super::pmull as intrinsics;
+
+#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+use super::clmul as intrinsics;
+
+#[cfg(all(target_arch = "aarch64", feature = "armv8"))]
+cpufeatures::new!(mul_intrinsics, "aes"); // `aes` implies PMULL
+
+#[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
+cpufeatures::new!(mul_intrinsics, "pclmulqdq", "sse4.1");
+
+/// **POLYVAL**: GHASH-like universal hash over GF(2^128).
+pub struct Polyval {
+    inner: Inner,
+    token: mul_intrinsics::InitToken,
+}
+
+union Inner {
+    intrinsics: ManuallyDrop<intrinsics::Polyval>,
+    soft: ManuallyDrop<soft::Polyval>,
+}
+
+impl NewUniversalHash for Polyval {
+    type KeySize = U16;
+
+    /// Initialize POLYVAL with the given `H` field element
+    fn new(h: &Key) -> Self {
+        let (token, has_intrinsics) = mul_intrinsics::init_get();
+
+        let inner = if has_intrinsics {
+            Inner {
+                intrinsics: ManuallyDrop::new(intrinsics::Polyval::new(h)),
+            }
+        } else {
+            Inner {
+                soft: ManuallyDrop::new(soft::Polyval::new(h)),
+            }
+        };
+
+        Self { inner, token }
+    }
+}
+
+impl UniversalHash for Polyval {
+    type BlockSize = U16;
+
+    /// Input a field element `X` to be authenticated
+    #[inline]
+    fn update(&mut self, x: &Block) {
+        if self.token.get() {
+            unsafe { (*self.inner.intrinsics).update(x) }
+        } else {
+            unsafe { (*self.inner.soft).update(x) }
+        }
+    }
+
+    /// Reset internal state
+    fn reset(&mut self) {
+        if self.token.get() {
+            unsafe { (*self.inner.intrinsics).reset() }
+        } else {
+            unsafe { (*self.inner.soft).reset() }
+        }
+    }
+
+    /// Get POLYVAL result (i.e. computed `S` field element)
+    fn finalize(self) -> Output<Self> {
+        let output_bytes = if self.token.get() {
+            unsafe {
+                ManuallyDrop::into_inner(self.inner.intrinsics)
+                    .finalize()
+                    .into_bytes()
+            }
+        } else {
+            unsafe {
+                ManuallyDrop::into_inner(self.inner.soft)
+                    .finalize()
+                    .into_bytes()
+            }
+        };
+
+        Output::new(output_bytes)
+    }
+}
+
+impl Clone for Polyval {
+    fn clone(&self) -> Self {
+        let inner = if self.token.get() {
+            Inner {
+                intrinsics: ManuallyDrop::new(unsafe { (*self.inner.intrinsics).clone() }),
+            }
+        } else {
+            Inner {
+                soft: ManuallyDrop::new(unsafe { (*self.inner.soft).clone() }),
+            }
+        };
+
+        Self {
+            inner,
+            token: self.token,
+        }
+    }
+}