1 // Copyright 2011 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // The original file was copied from sqlite, and was in the public domain.
6
7 /*
8 * This code implements the MD5 message-digest algorithm.
9 * The algorithm is due to Ron Rivest. This code was
10 * written by Colin Plumb in 1993, no copyright is claimed.
11 * This code is in the public domain; do with it what you wish.
12 *
13 * Equivalent code is available from RSA Data Security, Inc.
14 * This code has been tested against that, and is equivalent,
15 * except that you don't need to include two pages of legalese
16 * with every copy.
17 *
18 * To compute the message digest of a chunk of bytes, declare an
19 * MD5Context structure, pass it to MD5Init, call MD5Update as
20 * needed on buffers full of bytes, and then call MD5Final, which
21 * will fill a supplied 16-byte array with the digest.
22 */
23
24 #include <stddef.h>
25
26 #include <string_view>
27
28 #include "base/containers/span.h"
29 #include "base/hash/md5.h"
30 #include "base/strings/string_number_conversions.h"
31
32 namespace {
33
34 struct Context {
35 uint32_t buf[4];
36 uint32_t bits[2];
37 uint8_t in[64];
38 };
39
40 /*
41 * Note: this code is harmless on little-endian machines.
42 */
byteReverse(uint8_t * buf,unsigned longs)43 void byteReverse(uint8_t* buf, unsigned longs) {
44 do {
45 uint32_t temp =
46 static_cast<uint32_t>(static_cast<unsigned>(buf[3]) << 8 | buf[2])
47 << 16 |
48 (static_cast<unsigned>(buf[1]) << 8 | buf[0]);
49 *reinterpret_cast<uint32_t*>(buf) = temp;
50 buf += 4;
51 } while (--longs);
52 }
53
54 /* The four core functions - F1 is optimized somewhat */
55
56 /* #define F1(x, y, z) (x & y | ~x & z) */
57 #define F1(x, y, z) (z ^ (x & (y ^ z)))
58 #define F2(x, y, z) F1(z, x, y)
59 #define F3(x, y, z) (x ^ y ^ z)
60 #define F4(x, y, z) (y ^ (x | ~z))
61
62 /* This is the central step in the MD5 algorithm. */
63 #define MD5STEP(f, w, x, y, z, data, s) \
64 (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)
65
66 /*
67 * The core of the MD5 algorithm, this alters an existing MD5 hash to
68 * reflect the addition of 16 longwords of new data. MD5Update blocks
69 * the data and converts bytes into longwords for this routine.
70 */
MD5Transform(uint32_t buf[4],const uint32_t in[16])71 void MD5Transform(uint32_t buf[4], const uint32_t in[16]) {
72 uint32_t a, b, c, d;
73
74 a = buf[0];
75 b = buf[1];
76 c = buf[2];
77 d = buf[3];
78
79 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
80 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
81 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
82 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
83 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
84 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
85 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
86 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
87 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
88 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
89 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
90 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
91 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
92 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
93 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
94 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
95
96 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
97 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
98 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
99 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
100 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
101 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
102 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
103 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
104 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
105 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
106 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
107 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
108 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
109 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
110 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
111 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
112
113 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
114 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
115 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
116 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
117 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
118 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
119 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
120 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
121 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
122 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
123 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
124 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
125 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
126 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
127 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
128 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
129
130 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
131 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
132 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
133 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
134 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
135 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
136 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
137 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
138 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
139 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
140 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
141 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
142 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
143 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
144 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
145 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
146
147 buf[0] += a;
148 buf[1] += b;
149 buf[2] += c;
150 buf[3] += d;
151 }
152
153 } // namespace
154
155 namespace base {
156
157 /*
158 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
159 * initialization constants.
160 */
MD5Init(MD5Context * context)161 void MD5Init(MD5Context* context) {
162 struct Context* ctx = reinterpret_cast<struct Context*>(context);
163 ctx->buf[0] = 0x67452301;
164 ctx->buf[1] = 0xefcdab89;
165 ctx->buf[2] = 0x98badcfe;
166 ctx->buf[3] = 0x10325476;
167 ctx->bits[0] = 0;
168 ctx->bits[1] = 0;
169 }
170
171 /*
172 * Update context to reflect the concatenation of another buffer full
173 * of bytes.
174 */
MD5Update(MD5Context * context,std::string_view data)175 void MD5Update(MD5Context* context, std::string_view data) {
176 MD5Update(context, base::as_byte_span(data));
177 }
178
MD5Update(MD5Context * context,base::span<const uint8_t> data)179 void MD5Update(MD5Context* context, base::span<const uint8_t> data) {
180 struct Context* ctx = reinterpret_cast<struct Context*>(context);
181 const uint8_t* buf = data.data();
182 size_t len = data.size();
183
184 /* Update bitcount */
185
186 uint32_t t = ctx->bits[0];
187 if ((ctx->bits[0] = t + (static_cast<uint32_t>(len) << 3)) < t)
188 ctx->bits[1]++; /* Carry from low to high */
189 ctx->bits[1] += static_cast<uint32_t>(len >> 29);
190
191 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
192
193 /* Handle any leading odd-sized chunks */
194
195 if (t) {
196 uint8_t* p = static_cast<uint8_t*>(ctx->in + t);
197
198 t = 64 - t;
199 if (len < t) {
200 memcpy(p, buf, len);
201 return;
202 }
203 memcpy(p, buf, t);
204 byteReverse(ctx->in, 16);
205 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
206 buf += t;
207 len -= t;
208 }
209
210 /* Process data in 64-byte chunks */
211
212 while (len >= 64) {
213 memcpy(ctx->in, buf, 64);
214 byteReverse(ctx->in, 16);
215 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
216 buf += 64;
217 len -= 64;
218 }
219
220 /* Handle any remaining bytes of data. */
221
222 memcpy(ctx->in, buf, len);
223 }
224
225 /*
226 * Final wrapup - pad to 64-byte boundary with the bit pattern
227 * 1 0* (64-bit count of bits processed, MSB-first)
228 */
MD5Final(MD5Digest * digest,MD5Context * context)229 void MD5Final(MD5Digest* digest, MD5Context* context) {
230 struct Context* ctx = reinterpret_cast<struct Context*>(context);
231 unsigned count;
232 uint8_t* p;
233
234 /* Compute number of bytes mod 64 */
235 count = (ctx->bits[0] >> 3) & 0x3F;
236
237 /* Set the first char of padding to 0x80. This is safe since there is
238 always at least one byte free */
239 p = ctx->in + count;
240 *p++ = 0x80;
241
242 /* Bytes of padding needed to make 64 bytes */
243 count = 64 - 1 - count;
244
245 /* Pad out to 56 mod 64 */
246 if (count < 8) {
247 /* Two lots of padding: Pad the first block to 64 bytes */
248 memset(p, 0, count);
249 byteReverse(ctx->in, 16);
250 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
251
252 /* Now fill the next block with 56 bytes */
253 memset(ctx->in, 0, 56);
254 } else {
255 /* Pad block to 56 bytes */
256 memset(p, 0, count - 8);
257 }
258 byteReverse(ctx->in, 14);
259
260 /* Append length in bits and transform */
261 memcpy(&ctx->in[14 * sizeof(ctx->bits[0])], &ctx->bits[0],
262 sizeof(ctx->bits[0]));
263 memcpy(&ctx->in[15 * sizeof(ctx->bits[1])], &ctx->bits[1],
264 sizeof(ctx->bits[1]));
265
266 MD5Transform(ctx->buf, reinterpret_cast<uint32_t*>(ctx->in));
267 byteReverse(reinterpret_cast<uint8_t*>(ctx->buf), 4);
268 memcpy(digest->a, ctx->buf, 16);
269 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
270 }
271
MD5DigestToBase16(const MD5Digest & digest)272 std::string MD5DigestToBase16(const MD5Digest& digest) {
273 std::string ret;
274 ret.reserve(32);
275 for (uint8_t byte : digest.a) {
276 base::AppendHexEncodedByte(byte, ret, false);
277 }
278 return ret;
279 }
280
MD5Sum(span<const uint8_t> data,MD5Digest * digest)281 void MD5Sum(span<const uint8_t> data, MD5Digest* digest) {
282 MD5Context ctx;
283 MD5Init(&ctx);
284 span<const char> chars = as_chars(data);
285 MD5Update(&ctx, std::string_view(chars.data(), chars.size()));
286 MD5Final(digest, &ctx);
287 }
288
MD5String(std::string_view str)289 std::string MD5String(std::string_view str) {
290 MD5Digest digest;
291 MD5Sum(as_byte_span(str), &digest);
292 return MD5DigestToBase16(digest);
293 }
294
295 } // namespace base
296