FreeBSD/Linux Kernel Cross Reference
sys/kern/md4c.c
1 /* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2 * $FreeBSD: releng/5.1/sys/kern/md4c.c 75374 2001-04-10 07:59:06Z bp $
3 */
4
5 /* Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
6
7 License to copy and use this software is granted provided that it
8 is identified as the "RSA Data Security, Inc. MD4 Message-Digest
9 Algorithm" in all material mentioning or referencing this software
10 or this function.
11
12 License is also granted to make and use derivative works provided
13 that such works are identified as "derived from the RSA Data
14 Security, Inc. MD4 Message-Digest Algorithm" in all material
15 mentioning or referencing the derived work.
16
17 RSA Data Security, Inc. makes no representations concerning either
18 the merchantability of this software or the suitability of this
19 software for any particular purpose. It is provided "as is"
20 without express or implied warranty of any kind.
21
22 These notices must be retained in any copies of any part of this
23 documentation and/or software.
24 */
25
26 #include <sys/param.h>
27 #include <sys/systm.h>
28 #include <sys/md4.h>
29
30 typedef unsigned char *POINTER;
31 typedef u_int16_t UINT2;
32 typedef u_int32_t UINT4;
33
34 #define PROTO_LIST(list) list
35
36 /* Constants for MD4Transform routine.
37 */
38 #define S11 3
39 #define S12 7
40 #define S13 11
41 #define S14 19
42 #define S21 3
43 #define S22 5
44 #define S23 9
45 #define S24 13
46 #define S31 3
47 #define S32 9
48 #define S33 11
49 #define S34 15
50
51 static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
52 static void Encode PROTO_LIST
53 ((unsigned char *, UINT4 *, unsigned int));
54 static void Decode PROTO_LIST
55 ((UINT4 *, const unsigned char *, unsigned int));
56
57 static unsigned char PADDING[64] = {
58 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
59 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
60 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
61 };
62
63 /* F, G and H are basic MD4 functions.
64 */
65 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
66 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
67 #define H(x, y, z) ((x) ^ (y) ^ (z))
68
69 /* ROTATE_LEFT rotates x left n bits.
70 */
71 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
72
73 /* FF, GG and HH are transformations for rounds 1, 2 and 3 */
74 /* Rotation is separate from addition to prevent recomputation */
75 #define FF(a, b, c, d, x, s) { \
76 (a) += F ((b), (c), (d)) + (x); \
77 (a) = ROTATE_LEFT ((a), (s)); \
78 }
79 #define GG(a, b, c, d, x, s) { \
80 (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
81 (a) = ROTATE_LEFT ((a), (s)); \
82 }
83 #define HH(a, b, c, d, x, s) { \
84 (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
85 (a) = ROTATE_LEFT ((a), (s)); \
86 }
87
88 /* MD4 initialization. Begins an MD4 operation, writing a new context.
89 */
90 void MD4Init (context)
91 MD4_CTX *context; /* context */
92 {
93 context->count[0] = context->count[1] = 0;
94
95 /* Load magic initialization constants.
96 */
97 context->state[0] = 0x67452301;
98 context->state[1] = 0xefcdab89;
99 context->state[2] = 0x98badcfe;
100 context->state[3] = 0x10325476;
101 }
102
103 /* MD4 block update operation. Continues an MD4 message-digest
104 operation, processing another message block, and updating the
105 context.
106 */
107 void MD4Update (context, input, inputLen)
108 MD4_CTX *context; /* context */
109 const unsigned char *input; /* input block */
110 unsigned int inputLen; /* length of input block */
111 {
112 unsigned int i, index, partLen;
113
114 /* Compute number of bytes mod 64 */
115 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
116 /* Update number of bits */
117 if ((context->count[0] += ((UINT4)inputLen << 3))
118 < ((UINT4)inputLen << 3))
119 context->count[1]++;
120 context->count[1] += ((UINT4)inputLen >> 29);
121
122 partLen = 64 - index;
123 /* Transform as many times as possible.
124 */
125 if (inputLen >= partLen) {
126 bcopy(input, &context->buffer[index], partLen);
127 MD4Transform (context->state, context->buffer);
128
129 for (i = partLen; i + 63 < inputLen; i += 64)
130 MD4Transform (context->state, &input[i]);
131
132 index = 0;
133 }
134 else
135 i = 0;
136
137 /* Buffer remaining input */
138 bcopy(&input[i], &context->buffer[index], inputLen-i);
139 }
140
141 /* MD4 padding. */
142 void MD4Pad (context)
143 MD4_CTX *context; /* context */
144 {
145 unsigned char bits[8];
146 unsigned int index, padLen;
147
148 /* Save number of bits */
149 Encode (bits, context->count, 8);
150
151 /* Pad out to 56 mod 64.
152 */
153 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
154 padLen = (index < 56) ? (56 - index) : (120 - index);
155 MD4Update (context, PADDING, padLen);
156
157 /* Append length (before padding) */
158 MD4Update (context, bits, 8);
159 }
160
161 /* MD4 finalization. Ends an MD4 message-digest operation, writing the
162 the message digest and zeroizing the context.
163 */
164 void MD4Final (digest, context)
165 unsigned char digest[16]; /* message digest */
166 MD4_CTX *context; /* context */
167 {
168 /* Do padding */
169 MD4Pad (context);
170
171 /* Store state in digest */
172 Encode (digest, context->state, 16);
173
174 /* Zeroize sensitive information.
175 */
176 bzero((POINTER)context, sizeof (*context));
177 }
178
179 /* MD4 basic transformation. Transforms state based on block.
180 */
181 static void MD4Transform (state, block)
182 UINT4 state[4];
183 const unsigned char block[64];
184 {
185 UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
186
187 Decode (x, block, 64);
188
189 /* Round 1 */
190 FF (a, b, c, d, x[ 0], S11); /* 1 */
191 FF (d, a, b, c, x[ 1], S12); /* 2 */
192 FF (c, d, a, b, x[ 2], S13); /* 3 */
193 FF (b, c, d, a, x[ 3], S14); /* 4 */
194 FF (a, b, c, d, x[ 4], S11); /* 5 */
195 FF (d, a, b, c, x[ 5], S12); /* 6 */
196 FF (c, d, a, b, x[ 6], S13); /* 7 */
197 FF (b, c, d, a, x[ 7], S14); /* 8 */
198 FF (a, b, c, d, x[ 8], S11); /* 9 */
199 FF (d, a, b, c, x[ 9], S12); /* 10 */
200 FF (c, d, a, b, x[10], S13); /* 11 */
201 FF (b, c, d, a, x[11], S14); /* 12 */
202 FF (a, b, c, d, x[12], S11); /* 13 */
203 FF (d, a, b, c, x[13], S12); /* 14 */
204 FF (c, d, a, b, x[14], S13); /* 15 */
205 FF (b, c, d, a, x[15], S14); /* 16 */
206
207 /* Round 2 */
208 GG (a, b, c, d, x[ 0], S21); /* 17 */
209 GG (d, a, b, c, x[ 4], S22); /* 18 */
210 GG (c, d, a, b, x[ 8], S23); /* 19 */
211 GG (b, c, d, a, x[12], S24); /* 20 */
212 GG (a, b, c, d, x[ 1], S21); /* 21 */
213 GG (d, a, b, c, x[ 5], S22); /* 22 */
214 GG (c, d, a, b, x[ 9], S23); /* 23 */
215 GG (b, c, d, a, x[13], S24); /* 24 */
216 GG (a, b, c, d, x[ 2], S21); /* 25 */
217 GG (d, a, b, c, x[ 6], S22); /* 26 */
218 GG (c, d, a, b, x[10], S23); /* 27 */
219 GG (b, c, d, a, x[14], S24); /* 28 */
220 GG (a, b, c, d, x[ 3], S21); /* 29 */
221 GG (d, a, b, c, x[ 7], S22); /* 30 */
222 GG (c, d, a, b, x[11], S23); /* 31 */
223 GG (b, c, d, a, x[15], S24); /* 32 */
224
225 /* Round 3 */
226 HH (a, b, c, d, x[ 0], S31); /* 33 */
227 HH (d, a, b, c, x[ 8], S32); /* 34 */
228 HH (c, d, a, b, x[ 4], S33); /* 35 */
229 HH (b, c, d, a, x[12], S34); /* 36 */
230 HH (a, b, c, d, x[ 2], S31); /* 37 */
231 HH (d, a, b, c, x[10], S32); /* 38 */
232 HH (c, d, a, b, x[ 6], S33); /* 39 */
233 HH (b, c, d, a, x[14], S34); /* 40 */
234 HH (a, b, c, d, x[ 1], S31); /* 41 */
235 HH (d, a, b, c, x[ 9], S32); /* 42 */
236 HH (c, d, a, b, x[ 5], S33); /* 43 */
237 HH (b, c, d, a, x[13], S34); /* 44 */
238 HH (a, b, c, d, x[ 3], S31); /* 45 */
239 HH (d, a, b, c, x[11], S32); /* 46 */
240 HH (c, d, a, b, x[ 7], S33); /* 47 */
241 HH (b, c, d, a, x[15], S34); /* 48 */
242
243 state[0] += a;
244 state[1] += b;
245 state[2] += c;
246 state[3] += d;
247
248 /* Zeroize sensitive information.
249 */
250 bzero((POINTER)x, sizeof (x));
251 }
252
253 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
254 a multiple of 4.
255 */
256 static void Encode (output, input, len)
257 unsigned char *output;
258 UINT4 *input;
259 unsigned int len;
260 {
261 unsigned int i, j;
262
263 for (i = 0, j = 0; j < len; i++, j += 4) {
264 output[j] = (unsigned char)(input[i] & 0xff);
265 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
266 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
267 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
268 }
269 }
270
271 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
272 a multiple of 4.
273 */
274 static void Decode (output, input, len)
275
276 UINT4 *output;
277 const unsigned char *input;
278 unsigned int len;
279 {
280 unsigned int i, j;
281
282 for (i = 0, j = 0; j < len; i++, j += 4)
283 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
284 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
285 }
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