448 lines
14 KiB
Python
448 lines
14 KiB
Python
# SPDX-FileCopyrightText: 2017 Paul Sokolovsky
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# SPDX-FileCopyrightText: 2019 Brent Rubell for Adafruit Industries
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#
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# SPDX-License-Identifier: MIT
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"""
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`_sha256.py`
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======================================================
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SHA-256 Hash Algorithm.
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* Author(s): Tom St Denis, Paul Sokolovsky, Brent Rubell
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"""
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# pylint: disable=invalid-name, unnecessary-lambda, missing-docstring
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# SHA Block size and message digest sizes, in bytes.
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SHA_BLOCKSIZE = 64
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SHA_DIGESTSIZE = 32
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def new_shaobject():
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"""Struct. for storing SHA information."""
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return {
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"digest": [0] * 8,
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"count_lo": 0,
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"count_hi": 0,
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"data": [0] * SHA_BLOCKSIZE,
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"local": 0,
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"digestsize": 0,
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}
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# Various logical functions
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ROR = (
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lambda x, y: (((x & 0xFFFFFFFF) >> (y & 31)) | (x << (32 - (y & 31)))) & 0xFFFFFFFF
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)
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Ch = lambda x, y, z: (z ^ (x & (y ^ z)))
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Maj = lambda x, y, z: (((x | y) & z) | (x & y))
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S = lambda x, n: ROR(x, n)
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R = lambda x, n: (x & 0xFFFFFFFF) >> n
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Sigma0 = lambda x: (S(x, 2) ^ S(x, 13) ^ S(x, 22))
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Sigma1 = lambda x: (S(x, 6) ^ S(x, 11) ^ S(x, 25))
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Gamma0 = lambda x: (S(x, 7) ^ S(x, 18) ^ R(x, 3))
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Gamma1 = lambda x: (S(x, 17) ^ S(x, 19) ^ R(x, 10))
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# pylint: disable=too-many-statements
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def sha_transform(sha_info):
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W = []
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d = sha_info["data"]
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for i in range(0, 16):
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W.append(
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(d[4 * i] << 24) + (d[4 * i + 1] << 16) + (d[4 * i + 2] << 8) + d[4 * i + 3]
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)
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for i in range(16, 64):
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W.append(
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(Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16]) & 0xFFFFFFFF
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)
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ss = sha_info["digest"][:]
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# pylint: disable=too-many-arguments, line-too-long
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def RND(a, b, c, d, e, f, g, h, i, ki):
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"""Compress"""
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t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i]
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t1 = Sigma0(a) + Maj(a, b, c)
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d += t0
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h = t0 + t1
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return d & 0xFFFFFFFF, h & 0xFFFFFFFF
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 0, 0x428A2F98
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 1, 0x71374491
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 2, 0xB5C0FBCF
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 3, 0xE9B5DBA5
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 4, 0x3956C25B
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 5, 0x59F111F1
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 6, 0x923F82A4
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 7, 0xAB1C5ED5
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 8, 0xD807AA98
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 9, 0x12835B01
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 10, 0x243185BE
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 11, 0x550C7DC3
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 12, 0x72BE5D74
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 13, 0x80DEB1FE
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 14, 0x9BDC06A7
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 15, 0xC19BF174
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 16, 0xE49B69C1
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 17, 0xEFBE4786
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 18, 0x0FC19DC6
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 19, 0x240CA1CC
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 20, 0x2DE92C6F
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 21, 0x4A7484AA
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 22, 0x5CB0A9DC
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 23, 0x76F988DA
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 24, 0x983E5152
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 25, 0xA831C66D
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 26, 0xB00327C8
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 27, 0xBF597FC7
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 28, 0xC6E00BF3
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 29, 0xD5A79147
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 30, 0x06CA6351
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 31, 0x14292967
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 32, 0x27B70A85
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 33, 0x2E1B2138
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 34, 0x4D2C6DFC
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 35, 0x53380D13
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 36, 0x650A7354
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 37, 0x766A0ABB
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 38, 0x81C2C92E
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 39, 0x92722C85
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 40, 0xA2BFE8A1
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 41, 0xA81A664B
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 42, 0xC24B8B70
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 43, 0xC76C51A3
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 44, 0xD192E819
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 45, 0xD6990624
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 46, 0xF40E3585
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 47, 0x106AA070
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 48, 0x19A4C116
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 49, 0x1E376C08
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 50, 0x2748774C
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 51, 0x34B0BCB5
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 52, 0x391C0CB3
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 53, 0x4ED8AA4A
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 54, 0x5B9CCA4F
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 55, 0x682E6FF3
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)
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ss[3], ss[7] = RND(
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ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], 56, 0x748F82EE
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)
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ss[2], ss[6] = RND(
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ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], 57, 0x78A5636F
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)
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ss[1], ss[5] = RND(
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ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], ss[5], 58, 0x84C87814
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)
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ss[0], ss[4] = RND(
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ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], ss[4], 59, 0x8CC70208
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)
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ss[7], ss[3] = RND(
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ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], ss[3], 60, 0x90BEFFFA
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)
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ss[6], ss[2] = RND(
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ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], ss[2], 61, 0xA4506CEB
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)
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ss[5], ss[1] = RND(
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ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], ss[1], 62, 0xBEF9A3F7
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)
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ss[4], ss[0] = RND(
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ss[1], ss[2], ss[3], ss[4], ss[5], ss[6], ss[7], ss[0], 63, 0xC67178F2
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)
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# Feedback
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dig = []
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for i, x in enumerate(sha_info["digest"]):
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dig.append((x + ss[i]) & 0xFFFFFFFF)
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sha_info["digest"] = dig
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def sha_init():
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"""Initialize the SHA digest."""
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sha_info = new_shaobject()
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sha_info["digest"] = [
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0x6A09E667,
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0xBB67AE85,
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0x3C6EF372,
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0xA54FF53A,
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0x510E527F,
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0x9B05688C,
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0x1F83D9AB,
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0x5BE0CD19,
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]
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sha_info["count_lo"] = 0
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sha_info["count_hi"] = 0
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sha_info["local"] = 0
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sha_info["digestsize"] = 32
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return sha_info
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def sha224_init():
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"""Initialize a SHA224 digest."""
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sha_info = new_shaobject()
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sha_info["digest"] = [
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0xC1059ED8,
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0x367CD507,
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0x3070DD17,
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0xF70E5939,
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0xFFC00B31,
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0x68581511,
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0x64F98FA7,
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0xBEFA4FA4,
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]
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sha_info["count_lo"] = 0
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sha_info["count_hi"] = 0
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sha_info["local"] = 0
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sha_info["digestsize"] = 28
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return sha_info
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def getbuf(string):
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if isinstance(string, str):
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return string.encode("ascii")
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return bytes(string)
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def sha_update(sha_info, buffer):
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"""Update the SHA digest.
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:param dict sha_info: SHA Digest.
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:param str buffer: SHA buffer size.
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"""
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if isinstance(buffer, str):
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raise TypeError("Unicode strings must be encoded before hashing")
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size = len(buffer)
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buffer_idx = 0
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clo = (sha_info["count_lo"] + (size << 3)) & 0xFFFFFFFF
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if clo < sha_info["count_lo"]:
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sha_info["count_hi"] += 1
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sha_info["count_lo"] = clo
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sha_info["count_hi"] += size >> 29
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if sha_info["local"]:
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i = SHA_BLOCKSIZE - sha_info["local"]
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if i > size:
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i = size
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# copy sha buffer
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for x in enumerate(buffer[buffer_idx : buffer_idx + i]):
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sha_info["data"][sha_info["local"] + x[0]] = x[1]
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size -= i
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buffer_idx += i
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sha_info["local"] += i
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if sha_info["local"] == SHA_BLOCKSIZE:
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sha_transform(sha_info)
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sha_info["local"] = 0
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else:
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return
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while size >= SHA_BLOCKSIZE:
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# copy sha buffer
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sha_info["data"] = list(buffer[buffer_idx : buffer_idx + SHA_BLOCKSIZE])
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size -= SHA_BLOCKSIZE
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buffer_idx += SHA_BLOCKSIZE
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sha_transform(sha_info)
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# copy sha buffer
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pos = sha_info["local"]
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sha_info["data"][pos : pos + size] = list(buffer[buffer_idx : buffer_idx + size])
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sha_info["local"] = size
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def sha_final(sha_info):
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"""Finish computing the SHA Digest."""
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lo_bit_count = sha_info["count_lo"]
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hi_bit_count = sha_info["count_hi"]
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count = (lo_bit_count >> 3) & 0x3F
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sha_info["data"][count] = 0x80
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count += 1
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if count > SHA_BLOCKSIZE - 8:
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# zero the bytes in data after the count
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sha_info["data"] = sha_info["data"][:count] + ([0] * (SHA_BLOCKSIZE - count))
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sha_transform(sha_info)
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# zero bytes in data
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sha_info["data"] = [0] * SHA_BLOCKSIZE
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else:
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sha_info["data"] = sha_info["data"][:count] + ([0] * (SHA_BLOCKSIZE - count))
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sha_info["data"][56] = (hi_bit_count >> 24) & 0xFF
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sha_info["data"][57] = (hi_bit_count >> 16) & 0xFF
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sha_info["data"][58] = (hi_bit_count >> 8) & 0xFF
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sha_info["data"][59] = (hi_bit_count >> 0) & 0xFF
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sha_info["data"][60] = (lo_bit_count >> 24) & 0xFF
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sha_info["data"][61] = (lo_bit_count >> 16) & 0xFF
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sha_info["data"][62] = (lo_bit_count >> 8) & 0xFF
|
|
sha_info["data"][63] = (lo_bit_count >> 0) & 0xFF
|
|
|
|
sha_transform(sha_info)
|
|
|
|
dig = []
|
|
for i in sha_info["digest"]:
|
|
dig.extend(
|
|
[((i >> 24) & 0xFF), ((i >> 16) & 0xFF), ((i >> 8) & 0xFF), (i & 0xFF)]
|
|
)
|
|
return bytes(dig)
|
|
|
|
|
|
# pylint: disable=protected-access
|
|
class sha256:
|
|
digest_size = digestsize = SHA_DIGESTSIZE
|
|
block_size = SHA_BLOCKSIZE
|
|
name = "sha256"
|
|
|
|
def __init__(self, s=None):
|
|
"""Constructs a SHA256 hash object."""
|
|
self._sha = sha_init()
|
|
if s:
|
|
sha_update(self._sha, getbuf(s))
|
|
|
|
def update(self, s):
|
|
"""Updates the hash object with a bytes-like object, s."""
|
|
sha_update(self._sha, getbuf(s))
|
|
|
|
def digest(self):
|
|
"""Returns the digest of the data passed to the update()
|
|
method so far."""
|
|
return sha_final(self._sha.copy())[: self._sha["digestsize"]]
|
|
|
|
def hexdigest(self):
|
|
"""Like digest() except the digest is returned as a string object of
|
|
double length, containing only hexadecimal digits.
|
|
"""
|
|
return "".join(["%.2x" % i for i in self.digest()])
|
|
|
|
def copy(self):
|
|
"""Return a copy (“clone”) of the hash object."""
|
|
new = sha256()
|
|
new._sha = self._sha.copy()
|
|
return new
|
|
|
|
|
|
# pylint: disable=protected-access, super-init-not-called
|
|
class sha224(sha256):
|
|
digest_size = digestsize = 28
|
|
name = "sha224"
|
|
|
|
def __init__(self, s=None):
|
|
"""Constructs a SHA224 hash object."""
|
|
self._sha = sha224_init()
|
|
if s:
|
|
sha_update(self._sha, getbuf(s))
|
|
|
|
def copy(self):
|
|
"""Return a copy (“clone”) of the hash object."""
|
|
new = sha224()
|
|
new._sha = self._sha.copy()
|
|
return new
|