Implement SipHash in Python

1 files changed, 64 insertions, 0 deletions

diff --git a/qa/rpc-tests/test_framework/siphash.py b/qa/rpc-tests/test_framework/siphash.py
new file mode 100644
index 0000000000..9c0574bd93
--- /dev/null
+++ b/qa/rpc-tests/test_framework/siphash.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python3
+# Copyright (c) 2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#
+# siphash.py - Specialized SipHash-2-4 implementations
+#
+# This implements SipHash-2-4 for 256-bit integers.
+
+def rotl64(n, b):
+    return n >> (64 - b) | (n & ((1 << (64 - b)) - 1)) << b
+
+def siphash_round(v0, v1, v2, v3):
+    v0 = (v0 + v1) & ((1 << 64) - 1)
+    v1 = rotl64(v1, 13)
+    v1 ^= v0
+    v0 = rotl64(v0, 32)
+    v2 = (v2 + v3) & ((1 << 64) - 1)
+    v3 = rotl64(v3, 16)
+    v3 ^= v2
+    v0 = (v0 + v3) & ((1 << 64) - 1)
+    v3 = rotl64(v3, 21)
+    v3 ^= v0
+    v2 = (v2 + v1) & ((1 << 64) - 1)
+    v1 = rotl64(v1, 17)
+    v1 ^= v2
+    v2 = rotl64(v2, 32)
+    return (v0, v1, v2, v3)
+
+def siphash256(k0, k1, h):
+    n0 = h & ((1 << 64) - 1)
+    n1 = (h >> 64) & ((1 << 64) - 1)
+    n2 = (h >> 128) & ((1 << 64) - 1)
+    n3 = (h >> 192) & ((1 << 64) - 1)
+    v0 = 0x736f6d6570736575 ^ k0
+    v1 = 0x646f72616e646f6d ^ k1
+    v2 = 0x6c7967656e657261 ^ k0
+    v3 = 0x7465646279746573 ^ k1 ^ n0
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0 ^= n0
+    v3 ^= n1
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0 ^= n1
+    v3 ^= n2
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0 ^= n2
+    v3 ^= n3
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0 ^= n3
+    v3 ^= 0x2000000000000000
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0 ^= 0x2000000000000000
+    v2 ^= 0xFF
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3)
+    return v0 ^ v1 ^ v2 ^ v3