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1 /* | |
2 * Copyright (C) 2011 Google Inc. All rights reserved. | |
3 * | |
4 * Redistribution and use in source and binary forms, with or without | |
5 * modification, are permitted provided that the following conditions are | |
6 * met: | |
7 * | |
8 * * Redistributions of source code must retain the above copyright | |
9 * notice, this list of conditions and the following disclaimer. | |
10 * * Redistributions in binary form must reproduce the above | |
11 * copyright notice, this list of conditions and the following disclaimer | |
12 * in the documentation and/or other materials provided with the | |
13 * distribution. | |
14 * * Neither the name of Google Inc. nor the names of its | |
15 * contributors may be used to endorse or promote products derived from | |
16 * this software without specific prior written permission. | |
17 * | |
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
29 */ | |
30 | |
31 // A straightforward SHA-1 implementation based on RFC 3174. | |
32 // http://www.ietf.org/rfc/rfc3174.txt | |
33 // The names of functions and variables (such as "a", "b", and "f") follow notat
ions in RFC 3174. | |
34 | |
35 #include "config.h" | |
36 #include "wtf/SHA1.h" | |
37 | |
38 #include "wtf/Assertions.h" | |
39 | |
40 namespace WTF { | |
41 | |
42 static inline uint32_t f(int t, uint32_t b, uint32_t c, uint32_t d) | |
43 { | |
44 ASSERT(t >= 0 && t < 80); | |
45 if (t < 20) | |
46 return (b & c) | ((~b) & d); | |
47 if (t < 40) | |
48 return b ^ c ^ d; | |
49 if (t < 60) | |
50 return (b & c) | (b & d) | (c & d); | |
51 return b ^ c ^ d; | |
52 } | |
53 | |
54 static inline uint32_t k(int t) | |
55 { | |
56 ASSERT(t >= 0 && t < 80); | |
57 if (t < 20) | |
58 return 0x5a827999; | |
59 if (t < 40) | |
60 return 0x6ed9eba1; | |
61 if (t < 60) | |
62 return 0x8f1bbcdc; | |
63 return 0xca62c1d6; | |
64 } | |
65 | |
66 static inline uint32_t rotateLeft(int n, uint32_t x) | |
67 { | |
68 ASSERT(n >= 0 && n < 32); | |
69 return (x << n) | (x >> (32 - n)); | |
70 } | |
71 | |
72 SHA1::SHA1() | |
73 { | |
74 reset(); | |
75 } | |
76 | |
77 void SHA1::addBytes(const uint8_t* input, size_t length) | |
78 { | |
79 while (length--) { | |
80 ASSERT(m_cursor < 64); | |
81 m_buffer[m_cursor++] = *input++; | |
82 ++m_totalBytes; | |
83 if (m_cursor == 64) | |
84 processBlock(); | |
85 } | |
86 } | |
87 | |
88 void SHA1::computeHash(Vector<uint8_t, 20>& digest) | |
89 { | |
90 finalize(); | |
91 | |
92 digest.clear(); | |
93 digest.resize(20); | |
94 for (size_t i = 0; i < 5; ++i) { | |
95 // Treat hashValue as a big-endian value. | |
96 uint32_t hashValue = m_hash[i]; | |
97 for (int j = 0; j < 4; ++j) { | |
98 digest[4 * i + (3 - j)] = hashValue & 0xFF; | |
99 hashValue >>= 8; | |
100 } | |
101 } | |
102 | |
103 reset(); | |
104 } | |
105 | |
106 void SHA1::finalize() | |
107 { | |
108 ASSERT(m_cursor < 64); | |
109 m_buffer[m_cursor++] = 0x80; | |
110 if (m_cursor > 56) { | |
111 // Pad out to next block. | |
112 while (m_cursor < 64) | |
113 m_buffer[m_cursor++] = 0x00; | |
114 processBlock(); | |
115 } | |
116 | |
117 for (size_t i = m_cursor; i < 56; ++i) | |
118 m_buffer[i] = 0x00; | |
119 | |
120 // Write the length as a big-endian 64-bit value. | |
121 uint64_t bits = m_totalBytes * 8; | |
122 for (int i = 0; i < 8; ++i) { | |
123 m_buffer[56 + (7 - i)] = bits & 0xFF; | |
124 bits >>= 8; | |
125 } | |
126 m_cursor = 64; | |
127 processBlock(); | |
128 } | |
129 | |
130 void SHA1::processBlock() | |
131 { | |
132 ASSERT(m_cursor == 64); | |
133 | |
134 uint32_t w[80] = { 0 }; | |
135 for (int t = 0; t < 16; ++t) | |
136 w[t] = (m_buffer[t * 4] << 24) | (m_buffer[t * 4 + 1] << 16) | (m_buffer
[t * 4 + 2] << 8) | m_buffer[t * 4 + 3]; | |
137 for (int t = 16; t < 80; ++t) | |
138 w[t] = rotateLeft(1, w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16]); | |
139 | |
140 uint32_t a = m_hash[0]; | |
141 uint32_t b = m_hash[1]; | |
142 uint32_t c = m_hash[2]; | |
143 uint32_t d = m_hash[3]; | |
144 uint32_t e = m_hash[4]; | |
145 | |
146 for (int t = 0; t < 80; ++t) { | |
147 uint32_t temp = rotateLeft(5, a) + f(t, b, c, d) + e + w[t] + k(t); | |
148 e = d; | |
149 d = c; | |
150 c = rotateLeft(30, b); | |
151 b = a; | |
152 a = temp; | |
153 } | |
154 | |
155 m_hash[0] += a; | |
156 m_hash[1] += b; | |
157 m_hash[2] += c; | |
158 m_hash[3] += d; | |
159 m_hash[4] += e; | |
160 | |
161 m_cursor = 0; | |
162 } | |
163 | |
164 void SHA1::reset() | |
165 { | |
166 m_cursor = 0; | |
167 m_totalBytes = 0; | |
168 m_hash[0] = 0x67452301; | |
169 m_hash[1] = 0xefcdab89; | |
170 m_hash[2] = 0x98badcfe; | |
171 m_hash[3] = 0x10325476; | |
172 m_hash[4] = 0xc3d2e1f0; | |
173 | |
174 // Clear the buffer after use in case it's sensitive. | |
175 memset(m_buffer, 0, sizeof(m_buffer)); | |
176 } | |
177 | |
178 } // namespace WTF | |
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