WIP Add poseidon2 multihash

Author: markspanbroek

libp2p/multicodec.nim

@@ -176,6 +176,7 @@ const MultiCodecList = [
   ("skein1024-992", 0xB3DC), ("skein1024-1000", 0xB3DD),
   ("skein1024-1008", 0xB3DE), ("skein1024-1016", 0xB3DF),
   ("skein1024-1024", 0xB3E0),
+  ("poseidon2-alt_bn_128-a2-cdx1", 0xCD0001),
   # multiaddrs
   ("ip4", 0x04),
   ("ip6", 0x29),

libp2p/multihash.nim

@@ -25,6 +25,7 @@
 
 import tables
 import nimcrypto/[sha, sha2, keccak, blake2, hash, utils]
+import poseidon2
 import varint, vbuffer, multicodec, multibase
 import stew/base58
 import stew/results
@@ -179,6 +180,11 @@ proc shake_256hash(data: openArray[byte], output: var openArray[byte]) =
     discard sctx.output(addr output[0], uint(len(output)))
     sctx.clear()
 
+proc poseidon2hash(data: openArray[byte], output: var openArray[byte]) =
+  if len(output) > 0:
+    var digest = poseidon2.merkleRoot(data).toBytes()
+    copyMem(addr output[0], addr digest[0], uint(len(output)))
+
 const
   HashesList = [
     MHash(mcodec: multiCodec("identity"), size: 0,
@@ -315,7 +321,8 @@ const
     MHash(mcodec: multiCodec("blake2s-232"), size: 29, coder: blake2Shash),
     MHash(mcodec: multiCodec("blake2s-240"), size: 30, coder: blake2Shash),
     MHash(mcodec: multiCodec("blake2s-248"), size: 31, coder: blake2Shash),
-    MHash(mcodec: multiCodec("blake2s-256"), size: 32, coder: blake2Shash)
+    MHash(mcodec: multiCodec("blake2s-256"), size: 32, coder: blake2Shash),
+    MHash(mcodec: multiCodec("poseidon2-alt_bn_128-a2-cdx1"), size: 32, coder: poseidon2hash)
   ]
 
 proc initMultiHashCodeTable(): Table[MultiCodec, MHash] {.compileTime.} =

tests/testmultihash.nim

@@ -85,15 +85,31 @@ const
     ]
   ]
 
+const CodexTestVectors = [
+  [
+    "poseidon2-alt_bn_128-a2-cdx1",
+    "hello world",
+    # TODO: https://github.com/codex-storage/nim-poseidon2/issues/5#issuecomment-1787447258
+    "8180B406 20 68656C6C6F20776F726C64000000000000000000000000000000000000000000"
+  ]
+]
 
 suite "MultiHash test suite":
+
+  template checkTestVector(vector) =
+    var msg = vector[1]
+    var bmsg = cast[seq[byte]](msg)
+    var mh1 = MultiHash.digest(vector[0], bmsg).get()
+    var mh2 = MultiHash.init(stripSpaces(vector[2])).get()
+    check:
+      hex(mh1) == stripSpaces(vector[2])
+      hex(mh1) == hex(mh2)
+      mh1 == mh2
+
   test "rust-multihash test vectors":
     for item in RustTestVectors:
-      var msg = item[1]
-      var bmsg = cast[seq[byte]](msg)
-      var mh1 = MultiHash.digest(item[0], bmsg).get()
-      var mh2 = MultiHash.init(stripSpaces(item[2])).get()
-      check:
-        hex(mh1) == stripSpaces(item[2])
-        hex(mh1) == hex(mh2)
-        mh1 == mh2
+      checkTestVector(item)
+
+  test "codex test vectors":
+    for item in CodexTestVectors:
+      checkTestVector(item)