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1 /* |
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2 * Copyright 2013 Google Inc. |
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3 * |
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4 * Use of this source code is governed by a BSD-style license that can be |
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5 * found in the LICENSE file. |
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6 * |
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7 * The following code is based on the description in RFC 3174. |
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8 * http://www.ietf.org/rfc/rfc3174.txt |
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9 */ |
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10 |
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11 #include "SkTypes.h" |
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12 #include "SkSHA1.h" |
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13 #include <string.h> |
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14 |
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15 /** SHA1 basic transformation. Transforms state based on block. */ |
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16 static void transform(uint32_t state[5], const uint8_t block[64]); |
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17 |
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18 /** Encodes input into output (5 big endian 32 bit values). */ |
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19 static void encode(uint8_t output[20], const uint32_t input[5]); |
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20 |
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21 /** Encodes input into output (big endian 64 bit value). */ |
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22 static void encode(uint8_t output[8], const uint64_t input); |
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23 |
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24 SkSHA1::SkSHA1() : byteCount(0) { |
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25 // These are magic numbers from the specification. The first four are the same as MD5. |
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26 this->state[0] = 0x67452301; |
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27 this->state[1] = 0xefcdab89; |
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28 this->state[2] = 0x98badcfe; |
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29 this->state[3] = 0x10325476; |
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30 this->state[4] = 0xc3d2e1f0; |
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31 } |
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32 |
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33 void SkSHA1::update(const uint8_t* input, size_t inputLength) { |
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34 unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); |
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35 unsigned int bufferAvailable = 64 - bufferIndex; |
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36 |
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37 unsigned int inputIndex; |
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38 if (inputLength >= bufferAvailable) { |
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39 if (bufferIndex) { |
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40 memcpy(&this->buffer[bufferIndex], input, bufferAvailable); |
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41 transform(this->state, this->buffer); |
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42 inputIndex = bufferAvailable; |
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43 } else { |
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44 inputIndex = 0; |
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45 } |
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46 |
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47 for (; inputIndex + 63 < inputLength; inputIndex += 64) { |
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48 transform(this->state, &input[inputIndex]); |
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49 } |
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50 |
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51 bufferIndex = 0; |
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52 } else { |
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53 inputIndex = 0; |
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54 } |
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55 |
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56 memcpy(&this->buffer[bufferIndex], &input[inputIndex], inputLength - inputIndex); |
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57 |
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58 this->byteCount += inputLength; |
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59 } |
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60 |
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61 void SkSHA1::finish(Digest& digest) { |
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62 // Get the number of bits before padding. |
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63 uint8_t bits[8]; |
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64 encode(bits, this->byteCount << 3); |
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65 |
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66 // Pad out to 56 mod 64. |
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67 unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); |
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68 unsigned int paddingLength = (bufferIndex < 56) ? (56 - bufferIndex) : (120 - bufferIndex); |
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69 static uint8_t PADDING[64] = { |
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70 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
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71 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
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72 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
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73 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
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74 }; |
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75 this->update(PADDING, paddingLength); |
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76 |
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77 // Append length (length before padding, will cause final update). |
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78 this->update(bits, 8); |
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79 |
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80 // Write out digest. |
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81 encode(digest.data, this->state); |
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82 |
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83 #if defined(SK_SHA1_CLEAR_DATA) |
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84 // Clear state. |
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85 memset(this, 0, sizeof(*this)); |
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86 #endif |
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87 } |
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88 |
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89 struct F1 { uint32_t operator()(uint32_t B, uint32_t C, uint32_t D) { |
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90 return (B & C) | ((~B) & D); |
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91 //return D ^ (B & (C ^ D)); |
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92 //return (B & C) ^ ((~B) & D); |
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93 //return (B & C) + ((~B) & D); |
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94 //return _mm_or_ps(_mm_andnot_ps(B, D), _mm_and_ps(B, C)); //SSE2 |
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95 //return vec_sel(D, C, B); //PPC |
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96 }}; |
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97 |
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98 struct F2 { uint32_t operator()(uint32_t B, uint32_t C, uint32_t D) { |
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99 return B ^ C ^ D; |
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100 }}; |
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101 |
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102 struct F3 { uint32_t operator()(uint32_t B, uint32_t C, uint32_t D) { |
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103 return (B & C) | (B & D) | (C & D); |
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104 //return (B & C) | (D & (B | C)); |
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105 //return (B & C) | (D & (B ^ C)); |
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106 //return (B & C) + (D & (B ^ C)); |
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107 //return (B & C) ^ (B & D) ^ (C & D); |
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108 }}; |
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109 |
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110 /** Rotates x left n bits. */ |
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111 static inline uint32_t rotate_left(uint32_t x, uint8_t n) { |
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112 return (x << n) | (x >> (32 - n)); |
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113 } |
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114 |
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115 template <typename T> |
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116 static inline void operation(T operation, |
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117 uint32_t A, uint32_t& B, uint32_t C, uint32_t D, uint32_t& E, |
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118 uint32_t w, uint32_t k) { |
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119 E += rotate_left(A, 5) + operation(B, C, D) + w + k; |
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120 B = rotate_left(B, 30); |
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121 } |
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122 |
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123 static void transform(uint32_t state[5], const uint8_t block[64]) { |
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124 uint32_t A = state[0], B = state[1], C = state[2], D = state[3], E = state[4]; |
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125 |
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126 // Round constants defined in SHA-1. |
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127 static const uint32_t K[] = { |
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128 0x5A827999, //sqrt(2) * 2^30 |
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129 0x6ED9EBA1, //sqrt(3) * 2^30 |
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130 0x8F1BBCDC, //sqrt(5) * 2^30 |
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131 0xCA62C1D6, //sqrt(10) * 2^30 |
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132 }; |
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133 |
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134 uint32_t W[80]; |
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135 |
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136 // Initialize the array W. |
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137 size_t i = 0; |
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138 for (size_t j = 0; i < 16; ++i, j += 4) { |
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139 W[i] = (((uint32_t)block[j ]) << 24) | |
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140 (((uint32_t)block[j+1]) << 16) | |
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141 (((uint32_t)block[j+2]) << 8) | |
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142 (((uint32_t)block[j+3]) ); |
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143 } |
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144 for (; i < 80; ++i) { |
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145 W[i] = rotate_left(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1); |
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146 //The following is equivelent and speeds up SSE implementations, but slows non-SSE. |
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147 //W[i] = rotate_left(W[i-6] ^ W[i-16] ^ W[i-28] ^ W[i-32], 2); |
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148 } |
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149 |
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150 // Round 1 |
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151 operation(F1(), A, B, C, D, E, W[ 0], K[0]); |
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152 operation(F1(), E, A, B, C, D, W[ 1], K[0]); |
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153 operation(F1(), D, E, A, B, C, W[ 2], K[0]); |
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154 operation(F1(), C, D, E, A, B, W[ 3], K[0]); |
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155 operation(F1(), B, C, D, E, A, W[ 4], K[0]); |
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156 operation(F1(), A, B, C, D, E, W[ 5], K[0]); |
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157 operation(F1(), E, A, B, C, D, W[ 6], K[0]); |
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158 operation(F1(), D, E, A, B, C, W[ 7], K[0]); |
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159 operation(F1(), C, D, E, A, B, W[ 8], K[0]); |
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160 operation(F1(), B, C, D, E, A, W[ 9], K[0]); |
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161 operation(F1(), A, B, C, D, E, W[10], K[0]); |
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162 operation(F1(), E, A, B, C, D, W[11], K[0]); |
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163 operation(F1(), D, E, A, B, C, W[12], K[0]); |
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164 operation(F1(), C, D, E, A, B, W[13], K[0]); |
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165 operation(F1(), B, C, D, E, A, W[14], K[0]); |
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166 operation(F1(), A, B, C, D, E, W[15], K[0]); |
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167 operation(F1(), E, A, B, C, D, W[16], K[0]); |
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168 operation(F1(), D, E, A, B, C, W[17], K[0]); |
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169 operation(F1(), C, D, E, A, B, W[18], K[0]); |
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170 operation(F1(), B, C, D, E, A, W[19], K[0]); |
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171 |
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172 // Round 2 |
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173 operation(F2(), A, B, C, D, E, W[20], K[1]); |
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174 operation(F2(), E, A, B, C, D, W[21], K[1]); |
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175 operation(F2(), D, E, A, B, C, W[22], K[1]); |
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176 operation(F2(), C, D, E, A, B, W[23], K[1]); |
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177 operation(F2(), B, C, D, E, A, W[24], K[1]); |
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178 operation(F2(), A, B, C, D, E, W[25], K[1]); |
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179 operation(F2(), E, A, B, C, D, W[26], K[1]); |
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180 operation(F2(), D, E, A, B, C, W[27], K[1]); |
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181 operation(F2(), C, D, E, A, B, W[28], K[1]); |
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182 operation(F2(), B, C, D, E, A, W[29], K[1]); |
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183 operation(F2(), A, B, C, D, E, W[30], K[1]); |
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184 operation(F2(), E, A, B, C, D, W[31], K[1]); |
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185 operation(F2(), D, E, A, B, C, W[32], K[1]); |
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186 operation(F2(), C, D, E, A, B, W[33], K[1]); |
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187 operation(F2(), B, C, D, E, A, W[34], K[1]); |
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188 operation(F2(), A, B, C, D, E, W[35], K[1]); |
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189 operation(F2(), E, A, B, C, D, W[36], K[1]); |
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190 operation(F2(), D, E, A, B, C, W[37], K[1]); |
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191 operation(F2(), C, D, E, A, B, W[38], K[1]); |
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192 operation(F2(), B, C, D, E, A, W[39], K[1]); |
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193 |
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194 // Round 3 |
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195 operation(F3(), A, B, C, D, E, W[40], K[2]); |
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196 operation(F3(), E, A, B, C, D, W[41], K[2]); |
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197 operation(F3(), D, E, A, B, C, W[42], K[2]); |
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198 operation(F3(), C, D, E, A, B, W[43], K[2]); |
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199 operation(F3(), B, C, D, E, A, W[44], K[2]); |
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200 operation(F3(), A, B, C, D, E, W[45], K[2]); |
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201 operation(F3(), E, A, B, C, D, W[46], K[2]); |
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202 operation(F3(), D, E, A, B, C, W[47], K[2]); |
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203 operation(F3(), C, D, E, A, B, W[48], K[2]); |
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204 operation(F3(), B, C, D, E, A, W[49], K[2]); |
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205 operation(F3(), A, B, C, D, E, W[50], K[2]); |
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206 operation(F3(), E, A, B, C, D, W[51], K[2]); |
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207 operation(F3(), D, E, A, B, C, W[52], K[2]); |
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208 operation(F3(), C, D, E, A, B, W[53], K[2]); |
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209 operation(F3(), B, C, D, E, A, W[54], K[2]); |
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210 operation(F3(), A, B, C, D, E, W[55], K[2]); |
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211 operation(F3(), E, A, B, C, D, W[56], K[2]); |
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212 operation(F3(), D, E, A, B, C, W[57], K[2]); |
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213 operation(F3(), C, D, E, A, B, W[58], K[2]); |
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214 operation(F3(), B, C, D, E, A, W[59], K[2]); |
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215 |
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216 // Round 4 |
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217 operation(F2(), A, B, C, D, E, W[60], K[3]); |
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218 operation(F2(), E, A, B, C, D, W[61], K[3]); |
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219 operation(F2(), D, E, A, B, C, W[62], K[3]); |
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220 operation(F2(), C, D, E, A, B, W[63], K[3]); |
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221 operation(F2(), B, C, D, E, A, W[64], K[3]); |
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222 operation(F2(), A, B, C, D, E, W[65], K[3]); |
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223 operation(F2(), E, A, B, C, D, W[66], K[3]); |
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224 operation(F2(), D, E, A, B, C, W[67], K[3]); |
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225 operation(F2(), C, D, E, A, B, W[68], K[3]); |
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226 operation(F2(), B, C, D, E, A, W[69], K[3]); |
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227 operation(F2(), A, B, C, D, E, W[70], K[3]); |
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228 operation(F2(), E, A, B, C, D, W[71], K[3]); |
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229 operation(F2(), D, E, A, B, C, W[72], K[3]); |
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230 operation(F2(), C, D, E, A, B, W[73], K[3]); |
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231 operation(F2(), B, C, D, E, A, W[74], K[3]); |
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232 operation(F2(), A, B, C, D, E, W[75], K[3]); |
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233 operation(F2(), E, A, B, C, D, W[76], K[3]); |
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234 operation(F2(), D, E, A, B, C, W[77], K[3]); |
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235 operation(F2(), C, D, E, A, B, W[78], K[3]); |
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236 operation(F2(), B, C, D, E, A, W[79], K[3]); |
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237 |
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238 state[0] += A; |
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239 state[1] += B; |
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240 state[2] += C; |
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241 state[3] += D; |
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242 state[4] += E; |
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243 |
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244 #if defined(SK_SHA1_CLEAR_DATA) |
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245 // Clear sensitive information. |
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246 memset(W, 0, sizeof(W)); |
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247 #endif |
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248 } |
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249 |
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250 static void encode(uint8_t output[20], const uint32_t input[5]) { |
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251 for (size_t i = 0, j = 0; i < 5; i++, j += 4) { |
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252 output[j ] = (uint8_t)((input[i] >> 24) & 0xff); |
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253 output[j+1] = (uint8_t)((input[i] >> 16) & 0xff); |
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254 output[j+2] = (uint8_t)((input[i] >> 8) & 0xff); |
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255 output[j+3] = (uint8_t)((input[i] ) & 0xff); |
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256 } |
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257 } |
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258 |
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259 static void encode(uint8_t output[8], const uint64_t input) { |
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260 output[0] = (uint8_t)((input >> 56) & 0xff); |
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261 output[1] = (uint8_t)((input >> 48) & 0xff); |
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262 output[2] = (uint8_t)((input >> 40) & 0xff); |
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263 output[3] = (uint8_t)((input >> 32) & 0xff); |
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264 output[4] = (uint8_t)((input >> 24) & 0xff); |
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265 output[5] = (uint8_t)((input >> 16) & 0xff); |
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266 output[6] = (uint8_t)((input >> 8) & 0xff); |
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267 output[7] = (uint8_t)((input ) & 0xff); |
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268 } |