Annotation of src/usr.bin/ssh/ssh_md5.c, Revision 1.2
1.1 deraadt 1: /* This code has been heavily hacked by Tatu Ylonen <ylo@cs.hut.fi> to
2: make it compile on machines like Cray that don't have a 32 bit integer
3: type. */
4: /*
5: * This code implements the MD5 message-digest algorithm.
6: * The algorithm is due to Ron Rivest. This code was
7: * written by Colin Plumb in 1993, no copyright is claimed.
8: * This code is in the public domain; do with it what you wish.
9: *
10: * Equivalent code is available from RSA Data Security, Inc.
11: * This code has been tested against that, and is equivalent,
12: * except that you don't need to include two pages of legalese
13: * with every copy.
14: *
15: * To compute the message digest of a chunk of bytes, declare an
16: * MD5Context structure, pass it to MD5Init, call MD5Update as
17: * needed on buffers full of bytes, and then call MD5Final, which
18: * will fill a supplied 16-byte array with the digest.
19: */
20:
21: #include "includes.h"
22: #include "ssh_md5.h"
23: #include "getput.h"
24:
25: /*
26: * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
27: * initialization constants.
28: */
29: void MD5Init(struct MD5Context *ctx)
30: {
31: ctx->buf[0] = 0x67452301;
32: ctx->buf[1] = 0xefcdab89;
33: ctx->buf[2] = 0x98badcfe;
34: ctx->buf[3] = 0x10325476;
35:
36: ctx->bits[0] = 0;
37: ctx->bits[1] = 0;
38: }
39:
40: /*
41: * Update context to reflect the concatenation of another buffer full
42: * of bytes.
43: */
44: void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
45: {
1.2 ! deraadt 46: u_int32_t t;
1.1 deraadt 47:
48: /* Update bitcount */
49:
50: t = ctx->bits[0];
1.2 ! deraadt 51: if ((ctx->bits[0] = (t + ((u_int32_t)len << 3)) & 0xffffffff) < t)
1.1 deraadt 52: ctx->bits[1]++; /* Carry from low to high */
53: ctx->bits[1] += len >> 29;
54:
55: t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
56:
57: /* Handle any leading odd-sized chunks */
58:
59: if (t) {
60: unsigned char *p = ctx->in + t;
61:
62: t = 64 - t;
63: if (len < t) {
64: memcpy(p, buf, len);
65: return;
66: }
67: memcpy(p, buf, t);
68: MD5Transform(ctx->buf, ctx->in);
69: buf += t;
70: len -= t;
71: }
72: /* Process data in 64-byte chunks */
73:
74: while (len >= 64) {
75: memcpy(ctx->in, buf, 64);
76: MD5Transform(ctx->buf, ctx->in);
77: buf += 64;
78: len -= 64;
79: }
80:
81: /* Handle any remaining bytes of data. */
82:
83: memcpy(ctx->in, buf, len);
84: }
85:
86: /*
87: * Final wrapup - pad to 64-byte boundary with the bit pattern
88: * 1 0* (64-bit count of bits processed, MSB-first)
89: */
90: void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
91: {
92: unsigned count;
93: unsigned char *p;
94:
95: /* Compute number of bytes mod 64 */
96: count = (ctx->bits[0] >> 3) & 0x3F;
97:
98: /* Set the first char of padding to 0x80. This is safe since there is
99: always at least one byte free */
100: p = ctx->in + count;
101: *p++ = 0x80;
102:
103: /* Bytes of padding needed to make 64 bytes */
104: count = 64 - 1 - count;
105:
106: /* Pad out to 56 mod 64 */
107: if (count < 8) {
108: /* Two lots of padding: Pad the first block to 64 bytes */
109: memset(p, 0, count);
110: MD5Transform(ctx->buf, ctx->in);
111:
112: /* Now fill the next block with 56 bytes */
113: memset(ctx->in, 0, 56);
114: } else {
115: /* Pad block to 56 bytes */
116: memset(p, 0, count - 8);
117: }
118:
119: /* Append length in bits and transform */
120: PUT_32BIT_LSB_FIRST(ctx->in + 56, ctx->bits[0]);
121: PUT_32BIT_LSB_FIRST(ctx->in + 60, ctx->bits[1]);
122:
123: MD5Transform(ctx->buf, ctx->in);
124: PUT_32BIT_LSB_FIRST(digest, ctx->buf[0]);
125: PUT_32BIT_LSB_FIRST(digest + 4, ctx->buf[1]);
126: PUT_32BIT_LSB_FIRST(digest + 8, ctx->buf[2]);
127: PUT_32BIT_LSB_FIRST(digest + 12, ctx->buf[3]);
128: memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
129: }
130:
131: #ifndef ASM_MD5
132:
133: /* The four core functions - F1 is optimized somewhat */
134:
135: /* #define F1(x, y, z) (x & y | ~x & z) */
136: #define F1(x, y, z) (z ^ (x & (y ^ z)))
137: #define F2(x, y, z) F1(z, x, y)
138: #define F3(x, y, z) (x ^ y ^ z)
139: #define F4(x, y, z) (y ^ (x | ~z))
140:
141: /* This is the central step in the MD5 algorithm. */
142: #define MD5STEP(f, w, x, y, z, data, s) \
143: ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
144:
145: /*
146: * The core of the MD5 algorithm, this alters an existing MD5 hash to
147: * reflect the addition of 16 longwords of new data. MD5Update blocks
148: * the data and converts bytes into longwords for this routine.
149: */
1.2 ! deraadt 150: void MD5Transform(u_int32_t buf[4], const unsigned char inext[64])
1.1 deraadt 151: {
1.2 ! deraadt 152: register u_int32_t a, b, c, d, i;
! 153: u_int32_t in[16];
1.1 deraadt 154:
155: for (i = 0; i < 16; i++)
156: in[i] = GET_32BIT_LSB_FIRST(inext + 4 * i);
157:
158: a = buf[0];
159: b = buf[1];
160: c = buf[2];
161: d = buf[3];
162:
163: MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
164: MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
165: MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
166: MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
167: MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
168: MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
169: MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
170: MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
171: MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
172: MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
173: MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
174: MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
175: MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
176: MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
177: MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
178: MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
179:
180: MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
181: MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
182: MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
183: MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
184: MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
185: MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
186: MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
187: MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
188: MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
189: MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
190: MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
191: MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
192: MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
193: MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
194: MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
195: MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
196:
197: MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
198: MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
199: MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
200: MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
201: MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
202: MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
203: MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
204: MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
205: MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
206: MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
207: MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
208: MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
209: MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
210: MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
211: MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
212: MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
213:
214: MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
215: MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
216: MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
217: MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
218: MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
219: MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
220: MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
221: MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
222: MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
223: MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
224: MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
225: MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
226: MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
227: MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
228: MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
229: MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
230:
231: buf[0] += a;
232: buf[1] += b;
233: buf[2] += c;
234: buf[3] += d;
235: }
236:
237: #endif
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