FreeBSD/Linux Kernel Cross Reference
sys/kern/md4c.c
1 /* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2 */
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/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/md4.h>
32
33 typedef unsigned char *POINTER;
34 typedef u_int16_t UINT2;
35 typedef u_int32_t UINT4;
36
37 #define PROTO_LIST(list) list
38
39 /* Constants for MD4Transform routine.
40 */
41 #define S11 3
42 #define S12 7
43 #define S13 11
44 #define S14 19
45 #define S21 3
46 #define S22 5
47 #define S23 9
48 #define S24 13
49 #define S31 3
50 #define S32 9
51 #define S33 11
52 #define S34 15
53
54 static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
55 static void Encode PROTO_LIST
56 ((unsigned char *, UINT4 *, unsigned int));
57 static void Decode PROTO_LIST
58 ((UINT4 *, const unsigned char *, unsigned int));
59
60 static unsigned char PADDING[64] = {
61 0x80, 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, 0, 0, 0, 0,
63 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
64 };
65
66 /* F, G and H are basic MD4 functions.
67 */
68 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
69 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
70 #define H(x, y, z) ((x) ^ (y) ^ (z))
71
72 /* ROTATE_LEFT rotates x left n bits.
73 */
74 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
75
76 /* FF, GG and HH are transformations for rounds 1, 2 and 3 */
77 /* Rotation is separate from addition to prevent recomputation */
78 #define FF(a, b, c, d, x, s) { \
79 (a) += F ((b), (c), (d)) + (x); \
80 (a) = ROTATE_LEFT ((a), (s)); \
81 }
82 #define GG(a, b, c, d, x, s) { \
83 (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
84 (a) = ROTATE_LEFT ((a), (s)); \
85 }
86 #define HH(a, b, c, d, x, s) { \
87 (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
88 (a) = ROTATE_LEFT ((a), (s)); \
89 }
90
91 /* MD4 initialization. Begins an MD4 operation, writing a new context.
92 */
93 void
94 MD4Init(MD4_CTX *context)
95 {
96 context->count[0] = context->count[1] = 0;
97
98 /* Load magic initialization constants.
99 */
100 context->state[0] = 0x67452301;
101 context->state[1] = 0xefcdab89;
102 context->state[2] = 0x98badcfe;
103 context->state[3] = 0x10325476;
104 }
105
106 /* MD4 block update operation. Continues an MD4 message-digest
107 operation, processing another message block, and updating the
108 context.
109 */
110 void
111 MD4Update(MD4_CTX *context, const unsigned char *input,
112 unsigned int inputLen)
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
145 MD4Pad(MD4_CTX *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
167 MD4Final(unsigned char digest[static 16], MD4_CTX *context)
168 {
169 /* Do padding */
170 MD4Pad (context);
171
172 /* Store state in digest */
173 Encode (digest, context->state, 16);
174
175 /* Zeroize sensitive information.
176 */
177 bzero(context, sizeof (*context));
178 }
179
180 /* MD4 basic transformation. Transforms state based on block.
181 */
182 static void
183 MD4Transform(UINT4 state[4], 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
257 Encode(unsigned char *output, UINT4 *input, unsigned int len)
258 {
259 unsigned int i, j;
260
261 for (i = 0, j = 0; j < len; i++, j += 4) {
262 output[j] = (unsigned char)(input[i] & 0xff);
263 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
264 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
265 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
266 }
267 }
268
269 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
270 a multiple of 4.
271 */
272 static void
273 Decode(UINT4 *output, const unsigned char *input, unsigned int len)
274 {
275 unsigned int i, j;
276
277 for (i = 0, j = 0; j < len; i++, j += 4)
278 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
279 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
280 }
Cache object: 51d38e9360b9e27eaa9364a095aee2ec
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