Extract CSipHasher to it's own file in crypto/ directory.

This is a move-only commit with the exception of changes to includes.
2025-11-11 22:50:59 +01:00 · 2018-08-24 14:48:23 -07:00
parent 6b8d0a2164
commit 4fb789e9b2
15 changed files with 234 additions and 206 deletions
--- a/src/crypto/siphash.cpp
+++ b/src/crypto/siphash.cpp
@@ -0,0 +1,173 @@
+// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <crypto/siphash.h>
+
+#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
+
+#define SIPROUND do { \
+    v0 += v1; v1 = ROTL(v1, 13); v1 ^= v0; \
+    v0 = ROTL(v0, 32); \
+    v2 += v3; v3 = ROTL(v3, 16); v3 ^= v2; \
+    v0 += v3; v3 = ROTL(v3, 21); v3 ^= v0; \
+    v2 += v1; v1 = ROTL(v1, 17); v1 ^= v2; \
+    v2 = ROTL(v2, 32); \
+} while (0)
+
+CSipHasher::CSipHasher(uint64_t k0, uint64_t k1)
+{
+    v[0] = 0x736f6d6570736575ULL ^ k0;
+    v[1] = 0x646f72616e646f6dULL ^ k1;
+    v[2] = 0x6c7967656e657261ULL ^ k0;
+    v[3] = 0x7465646279746573ULL ^ k1;
+    count = 0;
+    tmp = 0;
+}
+
+CSipHasher& CSipHasher::Write(uint64_t data)
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+
+    assert(count % 8 == 0);
+
+    v3 ^= data;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= data;
+
+    v[0] = v0;
+    v[1] = v1;
+    v[2] = v2;
+    v[3] = v3;
+
+    count += 8;
+    return *this;
+}
+
+CSipHasher& CSipHasher::Write(const unsigned char* data, size_t size)
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+    uint64_t t = tmp;
+    int c = count;
+
+    while (size--) {
+        t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
+        c++;
+        if ((c & 7) == 0) {
+            v3 ^= t;
+            SIPROUND;
+            SIPROUND;
+            v0 ^= t;
+            t = 0;
+        }
+    }
+
+    v[0] = v0;
+    v[1] = v1;
+    v[2] = v2;
+    v[3] = v3;
+    count = c;
+    tmp = t;
+
+    return *this;
+}
+
+uint64_t CSipHasher::Finalize() const
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+
+    uint64_t t = tmp | (((uint64_t)count) << 56);
+
+    v3 ^= t;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= t;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
+
+uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val)
+{
+    /* Specialized implementation for efficiency */
+    uint64_t d = val.GetUint64(0);
+
+    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
+    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
+    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
+    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
+
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(1);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(2);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(3);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    v3 ^= ((uint64_t)4) << 59;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= ((uint64_t)4) << 59;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
+
+uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra)
+{
+    /* Specialized implementation for efficiency */
+    uint64_t d = val.GetUint64(0);
+
+    uint64_t v0 = 0x736f6d6570736575ULL ^ k0;
+    uint64_t v1 = 0x646f72616e646f6dULL ^ k1;
+    uint64_t v2 = 0x6c7967656e657261ULL ^ k0;
+    uint64_t v3 = 0x7465646279746573ULL ^ k1 ^ d;
+
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(1);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(2);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = val.GetUint64(3);
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    d = (((uint64_t)36) << 56) | extra;
+    v3 ^= d;
+    SIPROUND;
+    SIPROUND;
+    v0 ^= d;
+    v2 ^= 0xFF;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    SIPROUND;
+    return v0 ^ v1 ^ v2 ^ v3;
+}
--- a/src/crypto/siphash.h
+++ b/src/crypto/siphash.h
@@ -0,0 +1,47 @@
+// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_CRYPTO_SIPHASH_H
+#define BITCOIN_CRYPTO_SIPHASH_H
+
+#include <stdint.h>
+
+#include <uint256.h>
+
+/** SipHash-2-4 */
+class CSipHasher
+{
+private:
+    uint64_t v[4];
+    uint64_t tmp;
+    int count;
+
+public:
+    /** Construct a SipHash calculator initialized with 128-bit key (k0, k1) */
+    CSipHasher(uint64_t k0, uint64_t k1);
+    /** Hash a 64-bit integer worth of data
+     *  It is treated as if this was the little-endian interpretation of 8 bytes.
+     *  This function can only be used when a multiple of 8 bytes have been written so far.
+     */
+    CSipHasher& Write(uint64_t data);
+    /** Hash arbitrary bytes. */
+    CSipHasher& Write(const unsigned char* data, size_t size);
+    /** Compute the 64-bit SipHash-2-4 of the data written so far. The object remains untouched. */
+    uint64_t Finalize() const;
+};
+
+/** Optimized SipHash-2-4 implementation for uint256.
+ *
+ *  It is identical to:
+ *    SipHasher(k0, k1)
+ *      .Write(val.GetUint64(0))
+ *      .Write(val.GetUint64(1))
+ *      .Write(val.GetUint64(2))
+ *      .Write(val.GetUint64(3))
+ *      .Finalize()
+ */
+uint64_t SipHashUint256(uint64_t k0, uint64_t k1, const uint256& val);
+uint64_t SipHashUint256Extra(uint64_t k0, uint64_t k1, const uint256& val, uint32_t extra);
+
+#endif // BITCOIN_CRYPTO_SIPHASH_H