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63 lines
2.0 KiB
63 lines
2.0 KiB
#!/usr/bin/env python3 |
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# Copyright (c) 2016-2017 The Bitcoin Core developers |
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# Distributed under the MIT software license, see the accompanying |
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# file COPYING or http://www.opensource.org/licenses/mit-license.php. |
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"""Specialized SipHash-2-4 implementations. |
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This implements SipHash-2-4 for 256-bit integers. |
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""" |
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def rotl64(n, b): |
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return n >> (64 - b) | (n & ((1 << (64 - b)) - 1)) << b |
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def siphash_round(v0, v1, v2, v3): |
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v0 = (v0 + v1) & ((1 << 64) - 1) |
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v1 = rotl64(v1, 13) |
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v1 ^= v0 |
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v0 = rotl64(v0, 32) |
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v2 = (v2 + v3) & ((1 << 64) - 1) |
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v3 = rotl64(v3, 16) |
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v3 ^= v2 |
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v0 = (v0 + v3) & ((1 << 64) - 1) |
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v3 = rotl64(v3, 21) |
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v3 ^= v0 |
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v2 = (v2 + v1) & ((1 << 64) - 1) |
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v1 = rotl64(v1, 17) |
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v1 ^= v2 |
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v2 = rotl64(v2, 32) |
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return (v0, v1, v2, v3) |
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def siphash256(k0, k1, h): |
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n0 = h & ((1 << 64) - 1) |
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n1 = (h >> 64) & ((1 << 64) - 1) |
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n2 = (h >> 128) & ((1 << 64) - 1) |
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n3 = (h >> 192) & ((1 << 64) - 1) |
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v0 = 0x736f6d6570736575 ^ k0 |
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v1 = 0x646f72616e646f6d ^ k1 |
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v2 = 0x6c7967656e657261 ^ k0 |
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v3 = 0x7465646279746573 ^ k1 ^ n0 |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0 ^= n0 |
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v3 ^= n1 |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0 ^= n1 |
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v3 ^= n2 |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0 ^= n2 |
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v3 ^= n3 |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0 ^= n3 |
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v3 ^= 0x2000000000000000 |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0 ^= 0x2000000000000000 |
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v2 ^= 0xFF |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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v0, v1, v2, v3 = siphash_round(v0, v1, v2, v3) |
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return v0 ^ v1 ^ v2 ^ v3
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