[test/crypto] Use chacha20_block function in data_to_num3072

Author: stratospher

test/functional/test_framework/crypto/muhash.py

@@ -6,59 +6,13 @@
 import hashlib
 import unittest
 
-def rot32(v, bits):
-    """Rotate the 32-bit value v left by bits bits."""
-    bits %= 32  # Make sure the term below does not throw an exception
-    return ((v << bits) & 0xffffffff) | (v >> (32 - bits))
-
-def chacha20_doubleround(s):
-    """Apply a ChaCha20 double round to 16-element state array s.
-
-    See https://cr.yp.to/chacha/chacha-20080128.pdf and https://tools.ietf.org/html/rfc8439
-    """
-    QUARTER_ROUNDS = [(0, 4, 8, 12),
-                      (1, 5, 9, 13),
-                      (2, 6, 10, 14),
-                      (3, 7, 11, 15),
-                      (0, 5, 10, 15),
-                      (1, 6, 11, 12),
-                      (2, 7, 8, 13),
-                      (3, 4, 9, 14)]
-
-    for a, b, c, d in QUARTER_ROUNDS:
-        s[a] = (s[a] + s[b]) & 0xffffffff
-        s[d] = rot32(s[d] ^ s[a], 16)
-        s[c] = (s[c] + s[d]) & 0xffffffff
-        s[b] = rot32(s[b] ^ s[c], 12)
-        s[a] = (s[a] + s[b]) & 0xffffffff
-        s[d] = rot32(s[d] ^ s[a], 8)
-        s[c] = (s[c] + s[d]) & 0xffffffff
-        s[b] = rot32(s[b] ^ s[c], 7)
-
-def chacha20_32_to_384(key32):
-    """Specialized ChaCha20 implementation with 32-byte key, 0 IV, 384-byte output."""
-    # See RFC 8439 section 2.3 for chacha20 parameters
-    CONSTANTS = [0x61707865, 0x3320646e, 0x79622d32, 0x6b206574]
-
-    key_bytes = [0]*8
-    for i in range(8):
-        key_bytes[i] = int.from_bytes(key32[(4 * i):(4 * (i+1))], 'little')
-
-    INITIALIZATION_VECTOR = [0] * 4
-    init = CONSTANTS + key_bytes + INITIALIZATION_VECTOR
-    out = bytearray()
-    for counter in range(6):
-        init[12] = counter
-        s = init.copy()
-        for _ in range(10):
-            chacha20_doubleround(s)
-        for i in range(16):
-            out.extend(((s[i] + init[i]) & 0xffffffff).to_bytes(4, 'little'))
-    return bytes(out)
+from .chacha20 import chacha20_block
 
 def data_to_num3072(data):
     """Hash a 32-byte array data to a 3072-bit number using 6 Chacha20 operations."""
-    bytes384 = chacha20_32_to_384(data)
+    bytes384 = b""
+    for counter in range(6):
+        bytes384 += chacha20_block(data, bytes(12), counter)
     return int.from_bytes(bytes384, 'little')
 
 class MuHash3072:
@@ -99,12 +53,3 @@ def test_muhash(self):
         finalized = muhash.digest()
         # This mirrors the result in the C++ MuHash3072 unit test
         self.assertEqual(finalized[::-1].hex(), "10d312b100cbd32ada024a6646e40d3482fcff103668d2625f10002a607d5863")
-
-    def test_chacha20(self):
-        def chacha_check(key, result):
-            self.assertEqual(chacha20_32_to_384(key)[:64].hex(), result)
-
-        # Test vectors from https://tools.ietf.org/html/draft-agl-tls-chacha20poly1305-04#section-7
-        # Since the nonce is hardcoded to 0 in our function we only use those vectors.
-        chacha_check([0]*32, "76b8e0ada0f13d90405d6ae55386bd28bdd219b8a08ded1aa836efcc8b770dc7da41597c5157488d7724e03fb8d84a376a43b8f41518a11cc387b669b2ee6586")
-        chacha_check([0]*31 + [1], "4540f05a9f1fb296d7736e7b208e3c96eb4fe1834688d2604f450952ed432d41bbe2a0b6ea7566d2a5d1e7e20d42af2c53d792b1c43fea817e9ad275ae546963")