OLD | NEW |
1 /* | 1 // Copyright 2016 Google Inc. |
2 * Copyright 2012 Google Inc. | |
3 * | |
4 * Use of this source code is governed by a BSD-style license that can be | |
5 * found in the LICENSE file. | |
6 * | |
7 * The following code is based on the description in RFC 1321. | |
8 * http://www.ietf.org/rfc/rfc1321.txt | |
9 */ | |
10 | |
11 #include "SkTypes.h" | |
12 #include "SkMD5.h" | |
13 #include <string.h> | |
14 | |
15 /** MD5 basic transformation. Transforms state based on block. */ | |
16 static void transform(uint32_t state[4], const uint8_t block[64]); | |
17 | |
18 /** Encodes input into output (4 little endian 32 bit values). */ | |
19 static void encode(uint8_t output[16], const uint32_t input[4]); | |
20 | |
21 /** Encodes input into output (little endian 64 bit value). */ | |
22 static void encode(uint8_t output[8], const uint64_t input); | |
23 | |
24 /** Decodes input (4 little endian 32 bit values) into storage, if required. */ | |
25 static const uint32_t* decode(uint32_t storage[16], const uint8_t input[64]); | |
26 | |
27 SkMD5::SkMD5() : byteCount(0) { | |
28 // These are magic numbers from the specification. | |
29 this->state[0] = 0x67452301; | |
30 this->state[1] = 0xefcdab89; | |
31 this->state[2] = 0x98badcfe; | |
32 this->state[3] = 0x10325476; | |
33 } | |
34 | |
35 void SkMD5::update(const uint8_t* input, size_t inputLength) { | |
36 unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); | |
37 unsigned int bufferAvailable = 64 - bufferIndex; | |
38 | |
39 unsigned int inputIndex; | |
40 if (inputLength >= bufferAvailable) { | |
41 if (bufferIndex) { | |
42 memcpy(&this->buffer[bufferIndex], input, bufferAvailable); | |
43 transform(this->state, this->buffer); | |
44 inputIndex = bufferAvailable; | |
45 } else { | |
46 inputIndex = 0; | |
47 } | |
48 | |
49 for (; inputIndex + 63 < inputLength; inputIndex += 64) { | |
50 transform(this->state, &input[inputIndex]); | |
51 } | |
52 | |
53 bufferIndex = 0; | |
54 } else { | |
55 inputIndex = 0; | |
56 } | |
57 | |
58 memcpy(&this->buffer[bufferIndex], &input[inputIndex], inputLength - inputIn
dex); | |
59 | |
60 this->byteCount += inputLength; | |
61 } | |
62 | |
63 void SkMD5::finish(Digest& digest) { | |
64 // Get the number of bits before padding. | |
65 uint8_t bits[8]; | |
66 encode(bits, this->byteCount << 3); | |
67 | |
68 // Pad out to 56 mod 64. | |
69 unsigned int bufferIndex = (unsigned int)(this->byteCount & 0x3F); | |
70 unsigned int paddingLength = (bufferIndex < 56) ? (56 - bufferIndex) : (120
- bufferIndex); | |
71 static uint8_t PADDING[64] = { | |
72 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
73 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
74 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
75 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | |
76 }; | |
77 this->update(PADDING, paddingLength); | |
78 | |
79 // Append length (length before padding, will cause final update). | |
80 this->update(bits, 8); | |
81 | |
82 // Write out digest. | |
83 encode(digest.data, this->state); | |
84 | |
85 #if defined(SK_MD5_CLEAR_DATA) | |
86 // Clear state. | |
87 memset(this, 0, sizeof(*this)); | |
88 #endif | |
89 } | |
90 | |
91 struct F { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { | |
92 //return (x & y) | ((~x) & z); | |
93 return ((y ^ z) & x) ^ z; //equivelent but faster | |
94 }}; | |
95 | |
96 struct G { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { | |
97 return (x & z) | (y & (~z)); | |
98 //return ((x ^ y) & z) ^ y; //equivelent but slower | |
99 }}; | |
100 | |
101 struct H { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { | |
102 return x ^ y ^ z; | |
103 }}; | |
104 | |
105 struct I { uint32_t operator()(uint32_t x, uint32_t y, uint32_t z) { | |
106 return y ^ (x | (~z)); | |
107 }}; | |
108 | |
109 /** Rotates x left n bits. */ | |
110 static inline uint32_t rotate_left(uint32_t x, uint8_t n) { | |
111 return (x << n) | (x >> (32 - n)); | |
112 } | |
113 | |
114 template <typename T> | |
115 static inline void operation(T operation, uint32_t& a, uint32_t b, uint32_t c, u
int32_t d, | |
116 uint32_t x, uint8_t s, uint32_t t) { | |
117 a = b + rotate_left(a + operation(b, c, d) + x + t, s); | |
118 } | |
119 | |
120 static void transform(uint32_t state[4], const uint8_t block[64]) { | |
121 uint32_t a = state[0], b = state[1], c = state[2], d = state[3]; | |
122 | |
123 uint32_t storage[16]; | |
124 const uint32_t* X = decode(storage, block); | |
125 | |
126 // Round 1 | |
127 operation(F(), a, b, c, d, X[ 0], 7, 0xd76aa478); // 1 | |
128 operation(F(), d, a, b, c, X[ 1], 12, 0xe8c7b756); // 2 | |
129 operation(F(), c, d, a, b, X[ 2], 17, 0x242070db); // 3 | |
130 operation(F(), b, c, d, a, X[ 3], 22, 0xc1bdceee); // 4 | |
131 operation(F(), a, b, c, d, X[ 4], 7, 0xf57c0faf); // 5 | |
132 operation(F(), d, a, b, c, X[ 5], 12, 0x4787c62a); // 6 | |
133 operation(F(), c, d, a, b, X[ 6], 17, 0xa8304613); // 7 | |
134 operation(F(), b, c, d, a, X[ 7], 22, 0xfd469501); // 8 | |
135 operation(F(), a, b, c, d, X[ 8], 7, 0x698098d8); // 9 | |
136 operation(F(), d, a, b, c, X[ 9], 12, 0x8b44f7af); // 10 | |
137 operation(F(), c, d, a, b, X[10], 17, 0xffff5bb1); // 11 | |
138 operation(F(), b, c, d, a, X[11], 22, 0x895cd7be); // 12 | |
139 operation(F(), a, b, c, d, X[12], 7, 0x6b901122); // 13 | |
140 operation(F(), d, a, b, c, X[13], 12, 0xfd987193); // 14 | |
141 operation(F(), c, d, a, b, X[14], 17, 0xa679438e); // 15 | |
142 operation(F(), b, c, d, a, X[15], 22, 0x49b40821); // 16 | |
143 | |
144 // Round 2 | |
145 operation(G(), a, b, c, d, X[ 1], 5, 0xf61e2562); // 17 | |
146 operation(G(), d, a, b, c, X[ 6], 9, 0xc040b340); // 18 | |
147 operation(G(), c, d, a, b, X[11], 14, 0x265e5a51); // 19 | |
148 operation(G(), b, c, d, a, X[ 0], 20, 0xe9b6c7aa); // 20 | |
149 operation(G(), a, b, c, d, X[ 5], 5, 0xd62f105d); // 21 | |
150 operation(G(), d, a, b, c, X[10], 9, 0x2441453); // 22 | |
151 operation(G(), c, d, a, b, X[15], 14, 0xd8a1e681); // 23 | |
152 operation(G(), b, c, d, a, X[ 4], 20, 0xe7d3fbc8); // 24 | |
153 operation(G(), a, b, c, d, X[ 9], 5, 0x21e1cde6); // 25 | |
154 operation(G(), d, a, b, c, X[14], 9, 0xc33707d6); // 26 | |
155 operation(G(), c, d, a, b, X[ 3], 14, 0xf4d50d87); // 27 | |
156 operation(G(), b, c, d, a, X[ 8], 20, 0x455a14ed); // 28 | |
157 operation(G(), a, b, c, d, X[13], 5, 0xa9e3e905); // 29 | |
158 operation(G(), d, a, b, c, X[ 2], 9, 0xfcefa3f8); // 30 | |
159 operation(G(), c, d, a, b, X[ 7], 14, 0x676f02d9); // 31 | |
160 operation(G(), b, c, d, a, X[12], 20, 0x8d2a4c8a); // 32 | |
161 | |
162 // Round 3 | |
163 operation(H(), a, b, c, d, X[ 5], 4, 0xfffa3942); // 33 | |
164 operation(H(), d, a, b, c, X[ 8], 11, 0x8771f681); // 34 | |
165 operation(H(), c, d, a, b, X[11], 16, 0x6d9d6122); // 35 | |
166 operation(H(), b, c, d, a, X[14], 23, 0xfde5380c); // 36 | |
167 operation(H(), a, b, c, d, X[ 1], 4, 0xa4beea44); // 37 | |
168 operation(H(), d, a, b, c, X[ 4], 11, 0x4bdecfa9); // 38 | |
169 operation(H(), c, d, a, b, X[ 7], 16, 0xf6bb4b60); // 39 | |
170 operation(H(), b, c, d, a, X[10], 23, 0xbebfbc70); // 40 | |
171 operation(H(), a, b, c, d, X[13], 4, 0x289b7ec6); // 41 | |
172 operation(H(), d, a, b, c, X[ 0], 11, 0xeaa127fa); // 42 | |
173 operation(H(), c, d, a, b, X[ 3], 16, 0xd4ef3085); // 43 | |
174 operation(H(), b, c, d, a, X[ 6], 23, 0x4881d05); // 44 | |
175 operation(H(), a, b, c, d, X[ 9], 4, 0xd9d4d039); // 45 | |
176 operation(H(), d, a, b, c, X[12], 11, 0xe6db99e5); // 46 | |
177 operation(H(), c, d, a, b, X[15], 16, 0x1fa27cf8); // 47 | |
178 operation(H(), b, c, d, a, X[ 2], 23, 0xc4ac5665); // 48 | |
179 | |
180 // Round 4 | |
181 operation(I(), a, b, c, d, X[ 0], 6, 0xf4292244); // 49 | |
182 operation(I(), d, a, b, c, X[ 7], 10, 0x432aff97); // 50 | |
183 operation(I(), c, d, a, b, X[14], 15, 0xab9423a7); // 51 | |
184 operation(I(), b, c, d, a, X[ 5], 21, 0xfc93a039); // 52 | |
185 operation(I(), a, b, c, d, X[12], 6, 0x655b59c3); // 53 | |
186 operation(I(), d, a, b, c, X[ 3], 10, 0x8f0ccc92); // 54 | |
187 operation(I(), c, d, a, b, X[10], 15, 0xffeff47d); // 55 | |
188 operation(I(), b, c, d, a, X[ 1], 21, 0x85845dd1); // 56 | |
189 operation(I(), a, b, c, d, X[ 8], 6, 0x6fa87e4f); // 57 | |
190 operation(I(), d, a, b, c, X[15], 10, 0xfe2ce6e0); // 58 | |
191 operation(I(), c, d, a, b, X[ 6], 15, 0xa3014314); // 59 | |
192 operation(I(), b, c, d, a, X[13], 21, 0x4e0811a1); // 60 | |
193 operation(I(), a, b, c, d, X[ 4], 6, 0xf7537e82); // 61 | |
194 operation(I(), d, a, b, c, X[11], 10, 0xbd3af235); // 62 | |
195 operation(I(), c, d, a, b, X[ 2], 15, 0x2ad7d2bb); // 63 | |
196 operation(I(), b, c, d, a, X[ 9], 21, 0xeb86d391); // 64 | |
197 | |
198 state[0] += a; | |
199 state[1] += b; | |
200 state[2] += c; | |
201 state[3] += d; | |
202 | |
203 #if defined(SK_MD5_CLEAR_DATA) | |
204 // Clear sensitive information. | |
205 if (X == &storage) { | |
206 memset(storage, 0, sizeof(storage)); | |
207 } | |
208 #endif | |
209 } | |
210 | |
211 static void encode(uint8_t output[16], const uint32_t input[4]) { | |
212 for (size_t i = 0, j = 0; i < 4; i++, j += 4) { | |
213 output[j ] = (uint8_t) (input[i] & 0xff); | |
214 output[j+1] = (uint8_t)((input[i] >> 8) & 0xff); | |
215 output[j+2] = (uint8_t)((input[i] >> 16) & 0xff); | |
216 output[j+3] = (uint8_t)((input[i] >> 24) & 0xff); | |
217 } | |
218 } | |
219 | |
220 static void encode(uint8_t output[8], const uint64_t input) { | |
221 output[0] = (uint8_t) (input & 0xff); | |
222 output[1] = (uint8_t)((input >> 8) & 0xff); | |
223 output[2] = (uint8_t)((input >> 16) & 0xff); | |
224 output[3] = (uint8_t)((input >> 24) & 0xff); | |
225 output[4] = (uint8_t)((input >> 32) & 0xff); | |
226 output[5] = (uint8_t)((input >> 40) & 0xff); | |
227 output[6] = (uint8_t)((input >> 48) & 0xff); | |
228 output[7] = (uint8_t)((input >> 56) & 0xff); | |
229 } | |
230 | |
231 static inline bool is_aligned(const void *pointer, size_t byte_count) { | |
232 return reinterpret_cast<uintptr_t>(pointer) % byte_count == 0; | |
233 } | |
234 | |
235 static const uint32_t* decode(uint32_t storage[16], const uint8_t input[64]) { | |
236 #if defined(SK_CPU_LENDIAN) && defined(SK_CPU_FAST_UNALIGNED_ACCESS) | |
237 return reinterpret_cast<const uint32_t*>(input); | |
238 #else | |
239 #if defined(SK_CPU_LENDIAN) | |
240 if (is_aligned(input, 4)) { | |
241 return reinterpret_cast<const uint32_t*>(input); | |
242 } | |
243 #endif | |
244 for (size_t i = 0, j = 0; j < 64; i++, j += 4) { | |
245 storage[i] = ((uint32_t)input[j ]) | | |
246 (((uint32_t)input[j+1]) << 8) | | |
247 (((uint32_t)input[j+2]) << 16) | | |
248 (((uint32_t)input[j+3]) << 24); | |
249 } | |
250 return storage; | |
251 #endif | |
252 } | |
OLD | NEW |