xref: /freebsd/sys/kern/md4c.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
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 u_int16_t UINT2;
37 typedef u_int32_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 }
283