FreeBSD/Linux Kernel Cross Reference
sys/kern/md4c.c
1 /* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2 */
3
4 /* Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
5
6 License to copy and use this software is granted provided that it
7 is identified as the "RSA Data Security, Inc. MD4 Message-Digest
8 Algorithm" in all material mentioning or referencing this software
9 or this function.
10
11 License is also granted to make and use derivative works provided
12 that such works are identified as "derived from the RSA Data
13 Security, Inc. MD4 Message-Digest Algorithm" in all material
14 mentioning or referencing the derived work.
15
16 RSA Data Security, Inc. makes no representations concerning either
17 the merchantability of this software or the suitability of this
18 software for any particular purpose. It is provided "as is"
19 without express or implied warranty of any kind.
20
21 These notices must be retained in any copies of any part of this
22 documentation and/or software.
23 */
24
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD: releng/5.3/sys/kern/md4c.c 136588 2004-10-16 08:43:07Z cvs2svn $");
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/md4.h>
31
32 typedef unsigned char *POINTER;
33 typedef u_int16_t UINT2;
34 typedef u_int32_t UINT4;
35
36 #define PROTO_LIST(list) list
37
38 /* Constants for MD4Transform routine.
39 */
40 #define S11 3
41 #define S12 7
42 #define S13 11
43 #define S14 19
44 #define S21 3
45 #define S22 5
46 #define S23 9
47 #define S24 13
48 #define S31 3
49 #define S32 9
50 #define S33 11
51 #define S34 15
52
53 static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
54 static void Encode PROTO_LIST
55 ((unsigned char *, UINT4 *, unsigned int));
56 static void Decode PROTO_LIST
57 ((UINT4 *, const unsigned char *, unsigned int));
58
59 static unsigned char PADDING[64] = {
60 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
61 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
62 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
63 };
64
65 /* F, G and H are basic MD4 functions.
66 */
67 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
68 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
69 #define H(x, y, z) ((x) ^ (y) ^ (z))
70
71 /* ROTATE_LEFT rotates x left n bits.
72 */
73 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
74
75 /* FF, GG and HH are transformations for rounds 1, 2 and 3 */
76 /* Rotation is separate from addition to prevent recomputation */
77 #define FF(a, b, c, d, x, s) { \
78 (a) += F ((b), (c), (d)) + (x); \
79 (a) = ROTATE_LEFT ((a), (s)); \
80 }
81 #define GG(a, b, c, d, x, s) { \
82 (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
83 (a) = ROTATE_LEFT ((a), (s)); \
84 }
85 #define HH(a, b, c, d, x, s) { \
86 (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
87 (a) = ROTATE_LEFT ((a), (s)); \
88 }
89
90 /* MD4 initialization. Begins an MD4 operation, writing a new context.
91 */
92 void MD4Init (context)
93 MD4_CTX *context; /* context */
94 {
95 context->count[0] = context->count[1] = 0;
96
97 /* Load magic initialization constants.
98 */
99 context->state[0] = 0x67452301;
100 context->state[1] = 0xefcdab89;
101 context->state[2] = 0x98badcfe;
102 context->state[3] = 0x10325476;
103 }
104
105 /* MD4 block update operation. Continues an MD4 message-digest
106 operation, processing another message block, and updating the
107 context.
108 */
109 void MD4Update (context, input, inputLen)
110 MD4_CTX *context; /* context */
111 const unsigned char *input; /* input block */
112 unsigned int inputLen; /* length of input block */
113 {
114 unsigned int i, index, partLen;
115
116 /* Compute number of bytes mod 64 */
117 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
118 /* Update number of bits */
119 if ((context->count[0] += ((UINT4)inputLen << 3))
120 < ((UINT4)inputLen << 3))
121 context->count[1]++;
122 context->count[1] += ((UINT4)inputLen >> 29);
123
124 partLen = 64 - index;
125 /* Transform as many times as possible.
126 */
127 if (inputLen >= partLen) {
128 bcopy(input, &context->buffer[index], partLen);
129 MD4Transform (context->state, context->buffer);
130
131 for (i = partLen; i + 63 < inputLen; i += 64)
132 MD4Transform (context->state, &input[i]);
133
134 index = 0;
135 }
136 else
137 i = 0;
138
139 /* Buffer remaining input */
140 bcopy(&input[i], &context->buffer[index], inputLen-i);
141 }
142
143 /* MD4 padding. */
144 void MD4Pad (context)
145 MD4_CTX *context; /* context */
146 {
147 unsigned char bits[8];
148 unsigned int index, padLen;
149
150 /* Save number of bits */
151 Encode (bits, context->count, 8);
152
153 /* Pad out to 56 mod 64.
154 */
155 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
156 padLen = (index < 56) ? (56 - index) : (120 - index);
157 MD4Update (context, PADDING, padLen);
158
159 /* Append length (before padding) */
160 MD4Update (context, bits, 8);
161 }
162
163 /* MD4 finalization. Ends an MD4 message-digest operation, writing the
164 the message digest and zeroizing the context.
165 */
166 void MD4Final (digest, context)
167 unsigned char digest[16]; /* message digest */
168 MD4_CTX *context; /* context */
169 {
170 /* Do padding */
171 MD4Pad (context);
172
173 /* Store state in digest */
174 Encode (digest, context->state, 16);
175
176 /* Zeroize sensitive information.
177 */
178 bzero((POINTER)context, sizeof (*context));
179 }
180
181 /* MD4 basic transformation. Transforms state based on block.
182 */
183 static void MD4Transform (state, block)
184 UINT4 state[4];
185 const unsigned char block[64];
186 {
187 UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
188
189 Decode (x, block, 64);
190
191 /* Round 1 */
192 FF (a, b, c, d, x[ 0], S11); /* 1 */
193 FF (d, a, b, c, x[ 1], S12); /* 2 */
194 FF (c, d, a, b, x[ 2], S13); /* 3 */
195 FF (b, c, d, a, x[ 3], S14); /* 4 */
196 FF (a, b, c, d, x[ 4], S11); /* 5 */
197 FF (d, a, b, c, x[ 5], S12); /* 6 */
198 FF (c, d, a, b, x[ 6], S13); /* 7 */
199 FF (b, c, d, a, x[ 7], S14); /* 8 */
200 FF (a, b, c, d, x[ 8], S11); /* 9 */
201 FF (d, a, b, c, x[ 9], S12); /* 10 */
202 FF (c, d, a, b, x[10], S13); /* 11 */
203 FF (b, c, d, a, x[11], S14); /* 12 */
204 FF (a, b, c, d, x[12], S11); /* 13 */
205 FF (d, a, b, c, x[13], S12); /* 14 */
206 FF (c, d, a, b, x[14], S13); /* 15 */
207 FF (b, c, d, a, x[15], S14); /* 16 */
208
209 /* Round 2 */
210 GG (a, b, c, d, x[ 0], S21); /* 17 */
211 GG (d, a, b, c, x[ 4], S22); /* 18 */
212 GG (c, d, a, b, x[ 8], S23); /* 19 */
213 GG (b, c, d, a, x[12], S24); /* 20 */
214 GG (a, b, c, d, x[ 1], S21); /* 21 */
215 GG (d, a, b, c, x[ 5], S22); /* 22 */
216 GG (c, d, a, b, x[ 9], S23); /* 23 */
217 GG (b, c, d, a, x[13], S24); /* 24 */
218 GG (a, b, c, d, x[ 2], S21); /* 25 */
219 GG (d, a, b, c, x[ 6], S22); /* 26 */
220 GG (c, d, a, b, x[10], S23); /* 27 */
221 GG (b, c, d, a, x[14], S24); /* 28 */
222 GG (a, b, c, d, x[ 3], S21); /* 29 */
223 GG (d, a, b, c, x[ 7], S22); /* 30 */
224 GG (c, d, a, b, x[11], S23); /* 31 */
225 GG (b, c, d, a, x[15], S24); /* 32 */
226
227 /* Round 3 */
228 HH (a, b, c, d, x[ 0], S31); /* 33 */
229 HH (d, a, b, c, x[ 8], S32); /* 34 */
230 HH (c, d, a, b, x[ 4], S33); /* 35 */
231 HH (b, c, d, a, x[12], S34); /* 36 */
232 HH (a, b, c, d, x[ 2], S31); /* 37 */
233 HH (d, a, b, c, x[10], S32); /* 38 */
234 HH (c, d, a, b, x[ 6], S33); /* 39 */
235 HH (b, c, d, a, x[14], S34); /* 40 */
236 HH (a, b, c, d, x[ 1], S31); /* 41 */
237 HH (d, a, b, c, x[ 9], S32); /* 42 */
238 HH (c, d, a, b, x[ 5], S33); /* 43 */
239 HH (b, c, d, a, x[13], S34); /* 44 */
240 HH (a, b, c, d, x[ 3], S31); /* 45 */
241 HH (d, a, b, c, x[11], S32); /* 46 */
242 HH (c, d, a, b, x[ 7], S33); /* 47 */
243 HH (b, c, d, a, x[15], S34); /* 48 */
244
245 state[0] += a;
246 state[1] += b;
247 state[2] += c;
248 state[3] += d;
249
250 /* Zeroize sensitive information.
251 */
252 bzero((POINTER)x, sizeof (x));
253 }
254
255 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
256 a multiple of 4.
257 */
258 static void Encode (output, input, len)
259 unsigned char *output;
260 UINT4 *input;
261 unsigned int len;
262 {
263 unsigned int i, j;
264
265 for (i = 0, j = 0; j < len; i++, j += 4) {
266 output[j] = (unsigned char)(input[i] & 0xff);
267 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
268 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
269 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
270 }
271 }
272
273 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
274 a multiple of 4.
275 */
276 static void Decode (output, input, len)
277
278 UINT4 *output;
279 const unsigned char *input;
280 unsigned int len;
281 {
282 unsigned int i, j;
283
284 for (i = 0, j = 0; j < len; i++, j += 4)
285 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
286 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
287 }
Cache object: 136a11d1981b901a640293c5aa44f7fc
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