FreeBSD/Linux Kernel Cross Reference
sys/kern/md4c.c
1 /* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2 */
3
4 /*-
5 SPDX-License-Identifier: RSA-MD
6
7 Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
8
9 License to copy and use this software is granted provided that it
10 is identified as the "RSA Data Security, Inc. MD4 Message-Digest
11 Algorithm" in all material mentioning or referencing this software
12 or this function.
13
14 License is also granted to make and use derivative works provided
15 that such works are identified as "derived from the RSA Data
16 Security, Inc. MD4 Message-Digest Algorithm" in all material
17 mentioning or referencing the derived work.
18
19 RSA Data Security, Inc. makes no representations concerning either
20 the merchantability of this software or the suitability of this
21 software for any particular purpose. It is provided "as is"
22 without express or implied warranty of any kind.
23
24 These notices must be retained in any copies of any part of this
25 documentation and/or software.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/md4.h>
34
35 typedef unsigned char *POINTER;
36 typedef uint16_t UINT2;
37 typedef uint32_t UINT4;
38
39 #define PROTO_LIST(list) list
40
41 /* Constants for MD4Transform routine.
42 */
43 #define S11 3
44 #define S12 7
45 #define S13 11
46 #define S14 19
47 #define S21 3
48 #define S22 5
49 #define S23 9
50 #define S24 13
51 #define S31 3
52 #define S32 9
53 #define S33 11
54 #define S34 15
55
56 static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
57 static void Encode PROTO_LIST
58 ((unsigned char *, UINT4 *, unsigned int));
59 static void Decode PROTO_LIST
60 ((UINT4 *, const unsigned char *, unsigned int));
61
62 static unsigned char PADDING[64] = {
63 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
64 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
65 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
66 };
67
68 /* F, G and H are basic MD4 functions.
69 */
70 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
71 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
72 #define H(x, y, z) ((x) ^ (y) ^ (z))
73
74 /* ROTATE_LEFT rotates x left n bits.
75 */
76 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
77
78 /* FF, GG and HH are transformations for rounds 1, 2 and 3 */
79 /* Rotation is separate from addition to prevent recomputation */
80 #define FF(a, b, c, d, x, s) { \
81 (a) += F ((b), (c), (d)) + (x); \
82 (a) = ROTATE_LEFT ((a), (s)); \
83 }
84 #define GG(a, b, c, d, x, s) { \
85 (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
86 (a) = ROTATE_LEFT ((a), (s)); \
87 }
88 #define HH(a, b, c, d, x, s) { \
89 (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
90 (a) = ROTATE_LEFT ((a), (s)); \
91 }
92
93 /* MD4 initialization. Begins an MD4 operation, writing a new context.
94 */
95 void
96 MD4Init(MD4_CTX *context)
97 {
98 context->count[0] = context->count[1] = 0;
99
100 /* Load magic initialization constants.
101 */
102 context->state[0] = 0x67452301;
103 context->state[1] = 0xefcdab89;
104 context->state[2] = 0x98badcfe;
105 context->state[3] = 0x10325476;
106 }
107
108 /* MD4 block update operation. Continues an MD4 message-digest
109 operation, processing another message block, and updating the
110 context.
111 */
112 void
113 MD4Update(MD4_CTX *context, const unsigned char *input,
114 unsigned int inputLen)
115 {
116 unsigned int i, index, partLen;
117
118 /* Compute number of bytes mod 64 */
119 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
120 /* Update number of bits */
121 if ((context->count[0] += ((UINT4)inputLen << 3))
122 < ((UINT4)inputLen << 3))
123 context->count[1]++;
124 context->count[1] += ((UINT4)inputLen >> 29);
125
126 partLen = 64 - index;
127 /* Transform as many times as possible.
128 */
129 if (inputLen >= partLen) {
130 bcopy(input, &context->buffer[index], partLen);
131 MD4Transform (context->state, context->buffer);
132
133 for (i = partLen; i + 63 < inputLen; i += 64)
134 MD4Transform (context->state, &input[i]);
135
136 index = 0;
137 }
138 else
139 i = 0;
140
141 /* Buffer remaining input */
142 bcopy(&input[i], &context->buffer[index], inputLen-i);
143 }
144
145 /* MD4 padding. */
146 void
147 MD4Pad(MD4_CTX *context)
148 {
149 unsigned char bits[8];
150 unsigned int index, padLen;
151
152 /* Save number of bits */
153 Encode (bits, context->count, 8);
154
155 /* Pad out to 56 mod 64.
156 */
157 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
158 padLen = (index < 56) ? (56 - index) : (120 - index);
159 MD4Update (context, PADDING, padLen);
160
161 /* Append length (before padding) */
162 MD4Update (context, bits, 8);
163 }
164
165 /* MD4 finalization. Ends an MD4 message-digest operation, writing the
166 the message digest and zeroizing the context.
167 */
168 void
169 MD4Final(unsigned char digest[static 16], MD4_CTX *context)
170 {
171 /* Do padding */
172 MD4Pad (context);
173
174 /* Store state in digest */
175 Encode (digest, context->state, 16);
176
177 /* Zeroize sensitive information.
178 */
179 bzero(context, sizeof (*context));
180 }
181
182 /* MD4 basic transformation. Transforms state based on block.
183 */
184 static void
185 MD4Transform(UINT4 state[4], 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
259 Encode(unsigned char *output, UINT4 *input, 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
275 Decode(UINT4 *output, const unsigned char *input, unsigned int len)
276 {
277 unsigned int i, j;
278
279 for (i = 0, j = 0; j < len; i++, j += 4)
280 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
281 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
282 }
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