1 // Copyright 2019 The Chromium OS Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Note: this is the leveraged design from Chromium library src/base/hash/md5.cc
6
7 // The original file was copied from sqlite, and was in the public domain.
8
9 /*
10 * This code implements the MD5 message-digest algorithm.
11 * The algorithm is due to Ron Rivest. This code was
12 * written by Colin Plumb in 1993, no copyright is claimed.
13 * This code is in the public domain; do with it what you wish.
14 *
15 * Equivalent code is available from RSA Data Security, Inc.
16 * This code has been tested against that, and is equivalent,
17 * except that you don't need to include two pages of legalese
18 * with every copy.
19 *
20 * To compute the message digest of a chunk of bytes, declare an
21 * MD5Context structure, pass it to MD5Init, call MD5Update as
22 * needed on buffers full of bytes, and then call MD5Final, which
23 * will fill a supplied 16-byte array with the digest.
24 */
25
26 #include "md5.h"
27
28 #include <stddef.h>
29
30 namespace {
31
32 struct Context {
33 uint32_t buf[4];
34 uint32_t bits[2];
35 uint8_t in[64];
36 };
37
38 /*
39 * Note: this code is harmless on little-endian machines.
40 */
byteReverse(uint8_t * buf,unsigned longs)41 void byteReverse(uint8_t* buf, unsigned longs) {
42 do {
43 uint32_t temp = static_cast<uint32_t>(static_cast<unsigned>(buf[3]) << 8 | buf[2]) << 16 |
44 (static_cast<unsigned>(buf[1]) << 8 | buf[0]);
45 *reinterpret_cast<uint32_t*>(buf) = temp;
46 buf += 4;
47 } while (--longs);
48 }
49
50 /* The four core functions - F1 is optimized somewhat */
51
52 /* #define F1(x, y, z) (x & y | ~x & z) */
53 #define F1(x, y, z) (z ^ (x & (y ^ z)))
54 #define F2(x, y, z) F1(z, x, y)
55 #define F3(x, y, z) (x ^ y ^ z)
56 #define F4(x, y, z) (y ^ (x | ~z))
57
58 /* This is the central step in the MD5 algorithm. */
59 #define MD5STEP(f, w, x, y, z, data, s) (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)
60
61 /*
62 * The core of the MD5 algorithm, this alters an existing MD5 hash to
63 * reflect the addition of 16 longwords of new data. MD5Update blocks
64 * the data and converts bytes into longwords for this routine.
65 */
MD5Transform(uint32_t buf[4],const uint32_t in[16])66 void MD5Transform(uint32_t buf[4], const uint32_t in[16]) {
67 uint32_t a, b, c, d;
68
69 a = buf[0];
70 b = buf[1];
71 c = buf[2];
72 d = buf[3];
73
74 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
75 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
76 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
77 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
78 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
79 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
80 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
81 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
82 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
83 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
84 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
85 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
86 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
87 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
88 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
89 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
90
91 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
92 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
93 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
94 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
95 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
96 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
97 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
98 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
99 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
100 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
101 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
102 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
103 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
104 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
105 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
106 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
107
108 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
109 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
110 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
111 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
112 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
113 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
114 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
115 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
116 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
117 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
118 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
119 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
120 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
121 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
122 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
123 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
124
125 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
126 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
127 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
128 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
129 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
130 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
131 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
132 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
133 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
134 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
135 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
136 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
137 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
138 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
139 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
140 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
141
142 buf[0] += a;
143 buf[1] += b;
144 buf[2] += c;
145 buf[3] += d;
146 }
147
148 } // namespace
149
150 namespace android {
151
152 /*
153 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
154 * initialization constants.
155 */
MD5Init(MD5Context * context)156 void MD5Init(MD5Context* context) {
157 struct Context* ctx = reinterpret_cast<struct Context*>(context);
158 ctx->buf[0] = 0x67452301;
159 ctx->buf[1] = 0xefcdab89;
160 ctx->buf[2] = 0x98badcfe;
161 ctx->buf[3] = 0x10325476;
162 ctx->bits[0] = 0;
163 ctx->bits[1] = 0;
164 }
165
166 /*
167 * Update context to reflect the concatenation of another buffer full
168 * of bytes.
169 */
MD5Update(MD5Context * context,const std::string & data)170 void MD5Update(MD5Context* context, const std::string& data) {
171 struct Context* ctx = reinterpret_cast<struct Context*>(context);
172 const uint8_t* buf = reinterpret_cast<const uint8_t*>(data.data());
173 size_t len = data.size();
174
175 /* Update bitcount */
176
177 uint32_t t = ctx->bits[0];
178 if ((ctx->bits[0] = t + (static_cast<uint32_t>(len) << 3)) < t)
179 ctx->bits[1]++; /* Carry from low to high */
180 ctx->bits[1] += static_cast<uint32_t>(len >> 29);
181
182 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
183
184 /* Handle any leading odd-sized chunks */
185
186 if (t) {
187 uint8_t* p = static_cast<uint8_t*>(ctx->in + t);
188
189 t = 64 - t;
190 if (len < t) {
191 memcpy(p, buf, len);
192 return;
193 }
194 memcpy(p, buf, t);
195 byteReverse(ctx->in, 16);
196 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
197 buf += t;
198 len -= t;
199 }
200
201 /* Process data in 64-byte chunks */
202
203 while (len >= 64) {
204 memcpy(ctx->in, buf, 64);
205 byteReverse(ctx->in, 16);
206 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
207 buf += 64;
208 len -= 64;
209 }
210
211 /* Handle any remaining bytes of data. */
212
213 memcpy(ctx->in, buf, len);
214 }
215
216 /*
217 * Final wrapup - pad to 64-byte boundary with the bit pattern
218 * 1 0* (64-bit count of bits processed, MSB-first)
219 */
MD5Final(MD5Digest * digest,MD5Context * context)220 void MD5Final(MD5Digest* digest, MD5Context* context) {
221 struct Context* ctx = reinterpret_cast<struct Context*>(context);
222 unsigned count;
223 uint8_t* p;
224
225 /* Compute number of bytes mod 64 */
226 count = (ctx->bits[0] >> 3) & 0x3F;
227
228 /* Set the first char of padding to 0x80. This is safe since there is
229 always at least one byte free */
230 p = ctx->in + count;
231 *p++ = 0x80;
232
233 /* Bytes of padding needed to make 64 bytes */
234 count = 64 - 1 - count;
235
236 /* Pad out to 56 mod 64 */
237 if (count < 8) {
238 /* Two lots of padding: Pad the first block to 64 bytes */
239 memset(p, 0, count);
240 byteReverse(ctx->in, 16);
241 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
242
243 /* Now fill the next block with 56 bytes */
244 memset(ctx->in, 0, 56);
245 } else {
246 /* Pad block to 56 bytes */
247 memset(p, 0, count - 8);
248 }
249 byteReverse(ctx->in, 14);
250
251 /* Append length in bits and transform */
252 memcpy(&ctx->in[14 * sizeof(ctx->bits[0])], &ctx->bits[0], sizeof(ctx->bits[0]));
253 memcpy(&ctx->in[15 * sizeof(ctx->bits[1])], &ctx->bits[1], sizeof(ctx->bits[1]));
254
255 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
256 byteReverse(reinterpret_cast<uint8_t*>(ctx->buf), 4);
257 memcpy(digest->a, ctx->buf, 16);
258 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
259 }
260
MD5IntermediateFinal(MD5Digest * digest,const MD5Context * context)261 void MD5IntermediateFinal(MD5Digest* digest, const MD5Context* context) {
262 /* MD5Final mutates the MD5Context*. Make a copy for generating the
263 intermediate value. */
264 MD5Context context_copy;
265 memcpy(&context_copy, context, sizeof(context_copy));
266 MD5Final(digest, &context_copy);
267 }
268
MD5DigestToBase16(const MD5Digest & digest)269 std::string MD5DigestToBase16(const MD5Digest& digest) {
270 static char const zEncode[] = "0123456789abcdef";
271
272 std::string ret;
273 ret.resize(32);
274
275 for (int i = 0, j = 0; i < 16; i++, j += 2) {
276 uint8_t a = digest.a[i];
277 ret[j] = zEncode[(a >> 4) & 0xf];
278 ret[j + 1] = zEncode[a & 0xf];
279 }
280 return ret;
281 }
282
MD5Sum(const void * data,size_t length,MD5Digest * digest)283 void MD5Sum(const void* data, size_t length, MD5Digest* digest) {
284 MD5Context ctx;
285 MD5Init(&ctx);
286 MD5Update(&ctx, std::string(reinterpret_cast<const char*>(data), length));
287 MD5Final(digest, &ctx);
288 }
289
MD5String(const std::string & str)290 std::string MD5String(const std::string& str) {
291 MD5Digest digest;
292 MD5Sum(str.data(), str.length(), &digest);
293 return MD5DigestToBase16(digest);
294 }
295
296 } // namespace android
297