1/* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2 */
3
4#include <sys/cdefs.h>
5/*-
6   SPDX-License-Identifier: RSA-MD
7
8   Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
9
10   License to copy and use this software is granted provided that it
11   is identified as the "RSA Data Security, Inc. MD4 Message-Digest
12   Algorithm" in all material mentioning or referencing this software
13   or this function.
14
15   License is also granted to make and use derivative works provided
16   that such works are identified as "derived from the RSA Data
17   Security, Inc. MD4 Message-Digest Algorithm" in all material
18   mentioning or referencing the derived work.
19
20   RSA Data Security, Inc. makes no representations concerning either
21   the merchantability of this software or the suitability of this
22   software for any particular purpose. It is provided "as is"
23   without express or implied warranty of any kind.
24
25   These notices must be retained in any copies of any part of this
26   documentation and/or software.
27 */
28
29#include <sys/types.h>
30#include <string.h>
31#include "md4.h"
32
33typedef unsigned char *POINTER;
34typedef const unsigned char *CONST_POINTER;
35typedef u_int16_t UINT2;
36typedef u_int32_t UINT4;
37
38#define PROTO_LIST(list) list
39
40/* Constants for MD4Transform routine.
41 */
42#define S11 3
43#define S12 7
44#define S13 11
45#define S14 19
46#define S21 3
47#define S22 5
48#define S23 9
49#define S24 13
50#define S31 3
51#define S32 9
52#define S33 11
53#define S34 15
54
55static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
56static void Encode PROTO_LIST
57  ((unsigned char *, UINT4 *, unsigned int));
58static void Decode PROTO_LIST
59  ((UINT4 *, const unsigned char *, unsigned int));
60
61static unsigned char PADDING[64] = {
62  0x80, 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, 0, 0, 0, 0,
64  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
65};
66
67/* F, G and H are basic MD4 functions.
68 */
69#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
70#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
71#define H(x, y, z) ((x) ^ (y) ^ (z))
72
73/* ROTATE_LEFT rotates x left n bits.
74 */
75#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
76
77/* FF, GG and HH are transformations for rounds 1, 2 and 3 */
78/* Rotation is separate from addition to prevent recomputation */
79#define FF(a, b, c, d, x, s) { \
80    (a) += F ((b), (c), (d)) + (x); \
81    (a) = ROTATE_LEFT ((a), (s)); \
82  }
83#define GG(a, b, c, d, x, s) { \
84    (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
85    (a) = ROTATE_LEFT ((a), (s)); \
86  }
87#define HH(a, b, c, d, x, s) { \
88    (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
89    (a) = ROTATE_LEFT ((a), (s)); \
90  }
91
92/* MD4 initialization. Begins an MD4 operation, writing a new context.
93 */
94void
95MD4Init(MD4_CTX *context)
96{
97  context->count[0] = context->count[1] = 0;
98
99  /* Load magic initialization constants.
100   */
101  context->state[0] = 0x67452301;
102  context->state[1] = 0xefcdab89;
103  context->state[2] = 0x98badcfe;
104  context->state[3] = 0x10325476;
105}
106
107/* MD4 block update operation. Continues an MD4 message-digest
108     operation, processing another message block, and updating the
109     context.
110 */
111void
112MD4Update(MD4_CTX *context, const void *in, unsigned int inputLen)
113{
114  unsigned int i, idx, partLen;
115  const unsigned char *input = in;
116
117  /* Compute number of bytes mod 64 */
118  idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
119  /* Update number of bits */
120  if ((context->count[0] += ((UINT4)inputLen << 3))
121      < ((UINT4)inputLen << 3))
122    context->count[1]++;
123  context->count[1] += ((UINT4)inputLen >> 29);
124
125  partLen = 64 - idx;
126  /* Transform as many times as possible.
127   */
128  if (inputLen >= partLen) {
129    memcpy
130      ((POINTER)&context->buffer[idx], (CONST_POINTER)input, 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    idx = 0;
137  }
138  else
139    i = 0;
140
141  /* Buffer remaining input */
142  memcpy
143    ((POINTER)&context->buffer[idx], (CONST_POINTER)&input[i],
144     inputLen-i);
145}
146
147/* MD4 padding. */
148void
149MD4Pad(MD4_CTX *context)
150{
151  unsigned char bits[8];
152  unsigned int idx, padLen;
153
154  /* Save number of bits */
155  Encode (bits, context->count, 8);
156
157  /* Pad out to 56 mod 64.
158   */
159  idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
160  padLen = (idx < 56) ? (56 - idx) : (120 - idx);
161  MD4Update (context, PADDING, padLen);
162
163  /* Append length (before padding) */
164  MD4Update (context, bits, 8);
165}
166
167/* MD4 finalization. Ends an MD4 message-digest operation, writing the
168     the message digest and zeroizing the context.
169 */
170void
171MD4Final(unsigned char digest[16], MD4_CTX *context)
172{
173  /* Do padding */
174  MD4Pad (context);
175
176  /* Store state in digest */
177  Encode (digest, context->state, 16);
178
179  /* Zeroize sensitive information.
180   */
181  explicit_bzero(context, sizeof(*context));
182}
183
184/* MD4 basic transformation. Transforms state based on block.
185 */
186static void
187MD4Transform(UINT4 state[4], const unsigned char block[64])
188{
189  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
190
191  Decode (x, block, 64);
192
193  /* Round 1 */
194  FF (a, b, c, d, x[ 0], S11); /* 1 */
195  FF (d, a, b, c, x[ 1], S12); /* 2 */
196  FF (c, d, a, b, x[ 2], S13); /* 3 */
197  FF (b, c, d, a, x[ 3], S14); /* 4 */
198  FF (a, b, c, d, x[ 4], S11); /* 5 */
199  FF (d, a, b, c, x[ 5], S12); /* 6 */
200  FF (c, d, a, b, x[ 6], S13); /* 7 */
201  FF (b, c, d, a, x[ 7], S14); /* 8 */
202  FF (a, b, c, d, x[ 8], S11); /* 9 */
203  FF (d, a, b, c, x[ 9], S12); /* 10 */
204  FF (c, d, a, b, x[10], S13); /* 11 */
205  FF (b, c, d, a, x[11], S14); /* 12 */
206  FF (a, b, c, d, x[12], S11); /* 13 */
207  FF (d, a, b, c, x[13], S12); /* 14 */
208  FF (c, d, a, b, x[14], S13); /* 15 */
209  FF (b, c, d, a, x[15], S14); /* 16 */
210
211  /* Round 2 */
212  GG (a, b, c, d, x[ 0], S21); /* 17 */
213  GG (d, a, b, c, x[ 4], S22); /* 18 */
214  GG (c, d, a, b, x[ 8], S23); /* 19 */
215  GG (b, c, d, a, x[12], S24); /* 20 */
216  GG (a, b, c, d, x[ 1], S21); /* 21 */
217  GG (d, a, b, c, x[ 5], S22); /* 22 */
218  GG (c, d, a, b, x[ 9], S23); /* 23 */
219  GG (b, c, d, a, x[13], S24); /* 24 */
220  GG (a, b, c, d, x[ 2], S21); /* 25 */
221  GG (d, a, b, c, x[ 6], S22); /* 26 */
222  GG (c, d, a, b, x[10], S23); /* 27 */
223  GG (b, c, d, a, x[14], S24); /* 28 */
224  GG (a, b, c, d, x[ 3], S21); /* 29 */
225  GG (d, a, b, c, x[ 7], S22); /* 30 */
226  GG (c, d, a, b, x[11], S23); /* 31 */
227  GG (b, c, d, a, x[15], S24); /* 32 */
228
229  /* Round 3 */
230  HH (a, b, c, d, x[ 0], S31); /* 33 */
231  HH (d, a, b, c, x[ 8], S32); /* 34 */
232  HH (c, d, a, b, x[ 4], S33); /* 35 */
233  HH (b, c, d, a, x[12], S34); /* 36 */
234  HH (a, b, c, d, x[ 2], S31); /* 37 */
235  HH (d, a, b, c, x[10], S32); /* 38 */
236  HH (c, d, a, b, x[ 6], S33); /* 39 */
237  HH (b, c, d, a, x[14], S34); /* 40 */
238  HH (a, b, c, d, x[ 1], S31); /* 41 */
239  HH (d, a, b, c, x[ 9], S32); /* 42 */
240  HH (c, d, a, b, x[ 5], S33); /* 43 */
241  HH (b, c, d, a, x[13], S34); /* 44 */
242  HH (a, b, c, d, x[ 3], S31); /* 45 */
243  HH (d, a, b, c, x[11], S32); /* 46 */
244  HH (c, d, a, b, x[ 7], S33); /* 47 */
245  HH (b, c, d, a, x[15], S34); /* 48 */
246
247  state[0] += a;
248  state[1] += b;
249  state[2] += c;
250  state[3] += d;
251
252  /* Zeroize sensitive information.
253   */
254  memset ((POINTER)x, 0, sizeof (x));
255}
256
257/* Encodes input (UINT4) into output (unsigned char). Assumes len is
258     a multiple of 4.
259 */
260static void
261Encode(unsigned char *output, UINT4 *input, 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 */
276static void
277Decode(UINT4 *output, const unsigned char *input, unsigned int len)
278{
279  unsigned int i, j;
280
281  for (i = 0, j = 0; j < len; i++, j += 4)
282    output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
283      (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
284}
285
286#ifdef WEAK_REFS
287/* When building libmd, provide weak references. Note: this is not
288   activated in the context of compiling these sources for internal
289   use in libcrypt.
290 */
291#undef MD4Init
292__weak_reference(_libmd_MD4Init, MD4Init);
293#undef MD4Update
294__weak_reference(_libmd_MD4Update, MD4Update);
295#undef MD4Pad
296__weak_reference(_libmd_MD4Pad, MD4Pad);
297#undef MD4Final
298__weak_reference(_libmd_MD4Final, MD4Final);
299#endif
300