2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
22 void MD5Init(struct MD5Context *context);
23 void MD5Update(struct MD5Context *context, byte const *buf, int len);
24 void MD5Final(byte digest[16], struct MD5Context *context);
25 void MD5Transform(word32 buf[4], word32 const in[16]);
29 * Shuffle the bytes into little-endian order within words, as per the
30 * MD5 spec. Note: this code works regardless of the byte order.
33 byteSwap(word32 *buf, unsigned words)
35 byte *p = (byte *)buf;
38 *buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
39 ((unsigned)p[1] << 8 | p[0]);
45 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
46 * initialization constants.
49 MD5Init(struct MD5Context *ctx)
51 ctx->buf[0] = 0x67452301;
52 ctx->buf[1] = 0xefcdab89;
53 ctx->buf[2] = 0x98badcfe;
54 ctx->buf[3] = 0x10325476;
61 * Update context to reflect the concatenation of another buffer full
65 MD5Update(struct MD5Context *ctx, byte const *buf, int len)
69 /* Update byte count */
72 if ((ctx->bytes[0] = t + len) < t)
73 ctx->bytes[1]++; /* Carry from low to high */
75 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
76 if ((unsigned)t > len) {
77 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, len);
80 /* First chunk is an odd size */
81 memcpy((byte *)ctx->in + 64 - (unsigned)t, buf, (unsigned)t);
82 byteSwap(ctx->in, 16);
83 MD5Transform(ctx->buf, ctx->in);
87 /* Process data in 64-byte chunks */
89 memcpy(ctx->in, buf, 64);
90 byteSwap(ctx->in, 16);
91 MD5Transform(ctx->buf, ctx->in);
96 /* Handle any remaining bytes of data. */
97 memcpy(ctx->in, buf, len);
101 * Final wrapup - pad to 64-byte boundary with the bit pattern
102 * 1 0* (64-bit count of bits processed, MSB-first)
105 MD5Final(byte digest[16], struct MD5Context *ctx)
107 int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
108 byte *p = (byte *)ctx->in + count; /* First unused byte */
110 /* Set the first char of padding to 0x80. There is always room. */
113 /* Bytes of padding needed to make 56 bytes (-8..55) */
114 count = 56 - 1 - count;
116 if (count < 0) { /* Padding forces an extra block */
117 memset(p, 0, count+8);
118 byteSwap(ctx->in, 16);
119 MD5Transform(ctx->buf, ctx->in);
123 memset(p, 0, count+8);
124 byteSwap(ctx->in, 14);
126 /* Append length in bits and transform */
127 ctx->in[14] = ctx->bytes[0] << 3;
128 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
129 MD5Transform(ctx->buf, ctx->in);
131 byteSwap(ctx->buf, 4);
132 memcpy(digest, ctx->buf, 16);
133 memset(ctx,0,sizeof(ctx));
137 /* The four core functions - F1 is optimized somewhat */
139 /* #define F1(x, y, z) (x & y | ~x & z) */
140 #define F1(x, y, z) (z ^ (x & (y ^ z)))
141 #define F2(x, y, z) F1(z, x, y)
142 #define F3(x, y, z) (x ^ y ^ z)
143 #define F4(x, y, z) (y ^ (x | ~z))
145 /* This is the central step in the MD5 algorithm. */
146 #define MD5STEP(f,w,x,y,z,in,s) \
147 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
150 * The core of the MD5 algorithm, this alters an existing MD5 hash to
151 * reflect the addition of 16 longwords of new data. MD5Update blocks
152 * the data and converts bytes into longwords for this routine.
156 MD5Transform(word32 buf[4], word32 const in[16])
158 register word32 a, b, c, d;
165 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
166 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
167 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
168 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
169 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
170 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
171 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
172 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
173 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
174 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
175 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
176 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
177 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
178 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
179 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
180 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
182 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
183 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
184 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
185 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
186 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
187 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
188 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
189 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
190 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
191 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
192 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
193 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
194 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
195 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
196 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
197 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
199 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
200 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
201 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
202 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
203 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
204 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
205 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
206 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
207 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
208 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
209 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
210 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
211 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
212 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
213 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
214 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
216 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
217 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
218 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
219 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
220 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
221 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
222 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
223 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
224 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
225 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
226 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
227 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
228 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
229 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
230 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
231 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);