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.
17 * Changed so as no longer to depend on Colin Plumb's `usual.h' header
18 * definitions; now uses stuff from dpkg's config.h.
19 * - Ian Jackson <ian@chiark.greenend.org.uk>.
20 * Still in the public domain.
26 #ifdef WORDS_BIGENDIAN
28 byteSwap(uint32_t *buf, unsigned words)
30 uint8_t *p = (uint8_t*)buf;
33 *buf++ = (uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 |
34 ((unsigned)p[1] << 8 | p[0]);
39 #define byteSwap(buf,words)
42 /* The four core functions - F1 is optimized somewhat */
44 /* #define F1(x, y, z) (x & y | ~x & z) */
45 #define F1(x, y, z) (z ^ (x & (y ^ z)))
46 #define F2(x, y, z) F1(z, x, y)
47 #define F3(x, y, z) (x ^ y ^ z)
48 #define F4(x, y, z) (y ^ (x | ~z))
50 /* This is the central step in the MD5 algorithm. */
51 #define MD5STEP(f,w,x,y,z,in,s) \
52 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
55 * The core of the MD5 algorithm, this alters an existing MD5 hash to
56 * reflect the addition of 16 longwords of new data. MD5Update blocks
57 * the data and converts bytes into longwords for this routine.
60 MD5Transform(uint32_t buf[4], uint32_t const in[16])
62 register uint32_t a, b, c, d;
69 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
70 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
71 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
72 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
73 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
74 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
75 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
76 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
77 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
78 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
79 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
80 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
81 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
82 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
83 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
84 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
86 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
87 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
88 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
89 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
90 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
91 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
92 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
93 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
94 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
95 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
96 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
97 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
98 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
99 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
100 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
101 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
103 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
104 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
105 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
106 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
107 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
108 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
109 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
110 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
111 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
112 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
113 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
114 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
115 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
116 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
117 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
118 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
120 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
121 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
122 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
123 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
124 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
125 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
126 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
127 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
128 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
129 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
130 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
131 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
132 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
133 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
134 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
135 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
144 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
145 * initialization constants.
147 void MD5Init(struct MD5Context *ctx)
149 ctx->buf[0] = 0x67452301;
150 ctx->buf[1] = 0xefcdab89;
151 ctx->buf[2] = 0x98badcfe;
152 ctx->buf[3] = 0x10325476;
159 * Update context to reflect the concatenation of another buffer full
162 void MD5Update(struct MD5Context *ctx, const uint8_t *buf, unsigned len)
166 /* Update byte count */
169 if ((ctx->bytes[0] = t + len) < t)
170 ctx->bytes[1]++; /* Carry from low to high */
172 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
174 memcpy((uint8_t*)ctx->in + 64 - t, buf, len);
177 /* First chunk is an odd size */
178 memcpy((uint8_t*)ctx->in + 64 - t, buf, t);
179 byteSwap(ctx->in, 16);
180 MD5Transform(ctx->buf, ctx->in);
184 /* Process data in 64-byte chunks */
186 memcpy(ctx->in, buf, 64);
187 byteSwap(ctx->in, 16);
188 MD5Transform(ctx->buf, ctx->in);
193 /* Handle any remaining bytes of data. */
194 memcpy(ctx->in, buf, len);
198 * Final wrapup - pad to 64-byte boundary with the bit pattern
199 * 1 0* (64-bit count of bits processed, MSB-first)
201 void MD5Final(uint8_t digest[16], struct MD5Context *ctx)
203 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
204 uint8_t *p = (uint8_t*)ctx->in + count;
206 /* Set the first char of padding to 0x80. There is always room. */
209 /* Bytes of padding needed to make 56 bytes (-8..55) */
210 count = 56 - 1 - count;
212 if (count < 0) { /* Padding forces an extra block */
213 memset(p, 0, count + 8);
214 byteSwap(ctx->in, 16);
215 MD5Transform(ctx->buf, ctx->in);
216 p = (uint8_t*)ctx->in;
220 byteSwap(ctx->in, 14);
222 /* Append length in bits and transform */
223 ctx->in[14] = ctx->bytes[0] << 3;
224 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
225 MD5Transform(ctx->buf, ctx->in);
227 byteSwap(ctx->buf, 4);
228 memcpy(digest, ctx->buf, 16);
229 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */