1 files changed, 106 insertions, 0 deletions
diff --git a/vendor/hmac/src/simple.rs b/vendor/hmac/src/simple.rs
new file mode 100644
index 0000000..e28c4c3
--- /dev/null
+++ b/vendor/hmac/src/simple.rs
@@ -0,0 +1,106 @@
+use super::{get_der_key, IPAD, OPAD};
+use core::fmt;
+use digest::{
+    crypto_common::{Block, BlockSizeUser, InvalidLength, Key, KeySizeUser},
+    Digest, FixedOutput, KeyInit, MacMarker, Output, OutputSizeUser, Update,
+};
+#[cfg(feature = "reset")]
+use digest::{FixedOutputReset, Reset};
+
+/// Simplified HMAC instance able to operate over hash functions
+/// which do not expose block-level API and hash functions which
+/// process blocks lazily (e.g. BLAKE2).
+#[derive(Clone)]
+pub struct SimpleHmac<D: Digest + BlockSizeUser> {
+    digest: D,
+    opad_key: Block<D>,
+    #[cfg(feature = "reset")]
+    ipad_key: Block<D>,
+}
+
+impl<D: Digest + BlockSizeUser> KeySizeUser for SimpleHmac<D> {
+    type KeySize = D::BlockSize;
+}
+
+impl<D: Digest + BlockSizeUser> MacMarker for SimpleHmac<D> {}
+
+impl<D: Digest + BlockSizeUser> KeyInit for SimpleHmac<D> {
+    fn new(key: &Key<Self>) -> Self {
+        Self::new_from_slice(key.as_slice()).unwrap()
+    }
+
+    #[inline]
+    fn new_from_slice(key: &[u8]) -> Result<Self, InvalidLength> {
+        let der_key = get_der_key::<D>(key);
+        let mut ipad_key = der_key.clone();
+        for b in ipad_key.iter_mut() {
+            *b ^= IPAD;
+        }
+        let mut digest = D::new();
+        digest.update(&ipad_key);
+
+        let mut opad_key = der_key;
+        for b in opad_key.iter_mut() {
+            *b ^= OPAD;
+        }
+
+        Ok(Self {
+            digest,
+            opad_key,
+            #[cfg(feature = "reset")]
+            ipad_key,
+        })
+    }
+}
+
+impl<D: Digest + BlockSizeUser> Update for SimpleHmac<D> {
+    #[inline(always)]
+    fn update(&mut self, data: &[u8]) {
+        self.digest.update(data);
+    }
+}
+
+impl<D: Digest + BlockSizeUser> OutputSizeUser for SimpleHmac<D> {
+    type OutputSize = D::OutputSize;
+}
+
+impl<D: Digest + BlockSizeUser> FixedOutput for SimpleHmac<D> {
+    fn finalize_into(self, out: &mut Output<Self>) {
+        let mut h = D::new();
+        h.update(&self.opad_key);
+        h.update(&self.digest.finalize());
+        h.finalize_into(out);
+    }
+}
+
+impl<D: Digest + BlockSizeUser + fmt::Debug> fmt::Debug for SimpleHmac<D> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("SimpleHmac")
+            .field("digest", &self.digest)
+            // TODO: replace with `finish_non_exhaustive` on MSRV
+            // bump to 1.53
+            .field("..", &"..")
+            .finish()
+    }
+}
+
+#[cfg(feature = "reset")]
+#[cfg_attr(docsrs, doc(cfg(feature = "reset")))]
+impl<D: Digest + BlockSizeUser + Reset> Reset for SimpleHmac<D> {
+    fn reset(&mut self) {
+        Reset::reset(&mut self.digest);
+        self.digest.update(&self.ipad_key);
+    }
+}
+
+#[cfg(feature = "reset")]
+#[cfg_attr(docsrs, doc(cfg(feature = "reset")))]
+impl<D: Digest + BlockSizeUser + FixedOutputReset> FixedOutputReset for SimpleHmac<D> {
+    fn finalize_into_reset(&mut self, out: &mut Output<Self>) {
+        let mut h = D::new();
+        Update::update(&mut h, &self.opad_key);
+        Update::update(&mut h, &self.digest.finalize_reset());
+        Update::update(&mut self.digest, &self.ipad_key);
+        Digest::finalize_into(h, out);
+    }
+}