feat: add support for blake2b256 and blake2s128 (multiformats#44)

Adds support for blake2b256 and blake2s128.

src/hashes.rs

@@ -27,11 +27,11 @@ pub enum Hash {
     Keccak384,
     /// Keccak-512 (64-byte hash size)
     Keccak512,
-    /// Encoding unsupported
+    /// BLAKE2b-256 (32-byte hash size)
     Blake2b256,
     /// BLAKE2b-512 (64-byte hash size)
     Blake2b512,
-    /// Encoding unsupported
+    /// BLAKE2s-128 (16-byte hash size)
     Blake2s128,
     /// BLAKE2s-256 (32-byte hash size)
     Blake2s256,

src/lib.rs

@@ -11,8 +11,8 @@ mod hashes;
 
 use std::convert::TryFrom;
 
-use blake2b_simd::blake2b;
-use blake2s_simd::blake2s;
+use blake2b_simd::{blake2b, Params as Blake2bVariable};
+use blake2s_simd::{blake2s, Params as Blake2sVariable};
 use bytes::{BufMut, Bytes, BytesMut};
 use sha2::Digest;
 use tiny_keccak::Keccak;
@@ -42,6 +42,22 @@ macro_rules! encode {
         let hash = $algorithm($input);
         $output.copy_from_slice(hash.as_ref());
     }};
+    (blake2_256, $constructor:ident, $input:expr, $output:expr) => {{
+        let hash = $constructor::new()
+            .hash_length(32)
+            .to_state()
+            .update($input)
+            .finalize();
+        $output.copy_from_slice(hash.as_ref());
+    }};
+    (blake2_128, $constructor:ident, $input:expr, $output:expr) => {{
+        let hash = $constructor::new()
+            .hash_length(16)
+            .to_state()
+            .update($input)
+            .finalize();
+        $output.copy_from_slice(hash.as_ref());
+    }};
 }
 
 // And another one to keep the matching DRY
@@ -113,7 +129,9 @@ pub fn encode(hash: Hash, input: &[u8]) -> Result<Multihash, EncodeError> {
             Keccak384 => tiny::new_keccak384,
             Keccak512 => tiny::new_keccak512,
             Blake2b512 => blake2::blake2b,
+            Blake2b256 => blake2_256::Blake2bVariable,
             Blake2s256 => blake2::blake2s,
+            Blake2s128 => blake2_128::Blake2sVariable,
         });
 
         Ok(Multihash {

tests/lib.rs

@@ -41,6 +41,8 @@ fn multihash_encode() {
         Keccak512, b"hello world", "1D403ee2b40047b8060f68c67242175660f4174d0af5c01d47168ec20ed619b0b7c42181f40aa1046f39e2ef9efc6910782a998e0013d172458957957fac9405b67d";
         Blake2b512, b"hello world", "c0e40240021ced8799296ceca557832ab941a50b4a11f83478cf141f51f933f653ab9fbcc05a037cddbed06e309bf334942c4e58cdf1a46e237911ccd7fcf9787cbc7fd0";
         Blake2s256, b"hello world", "e0e402209aec6806794561107e594b1f6a8a6b0c92a0cba9acf5e5e93cca06f781813b0b";
+        Blake2b256, b"hello world", "a0e40220256c83b297114d201b30179f3f0ef0cace9783622da5974326b436178aeef610";
+        Blake2s128, b"hello world", "d0e4021037deae0226c30da2ab424a7b8ee14e83";
     }
 }
 
@@ -75,6 +77,8 @@ fn assert_decode() {
         Keccak512, "1D403ee2b40047b8060f68c67242175660f4174d0af5c01d47168ec20ed619b0b7c42181f40aa1046f39e2ef9efc6910782a998e0013d172458957957fac9405b67d";
         Blake2b512, "c0e40240021ced8799296ceca557832ab941a50b4a11f83478cf141f51f933f653ab9fbcc05a037cddbed06e309bf334942c4e58cdf1a46e237911ccd7fcf9787cbc7fd0";
         Blake2s256, "e0e402209aec6806794561107e594b1f6a8a6b0c92a0cba9acf5e5e93cca06f781813b0b";
+        Blake2b256, "a0e40220256c83b297114d201b30179f3f0ef0cace9783622da5974326b436178aeef610";
+        Blake2s128, "d0e4021037deae0226c30da2ab424a7b8ee14e83";
     }
 }
 
@@ -209,6 +213,16 @@ fn multihash_methods() {
         "e0e40220",
         "9aec6806794561107e594b1f6a8a6b0c92a0cba9acf5e5e93cca06f781813b0b",
     );
+    test_methods(
+        Hash::Blake2b256,
+        "a0e40220",
+        "256c83b297114d201b30179f3f0ef0cace9783622da5974326b436178aeef610",
+    );
+    test_methods(
+        Hash::Blake2s128,
+        "d0e40210",
+        "37deae0226c30da2ab424a7b8ee14e83",
+    );
 }
 
 #[test]