xref: /freebsd/sys/kern/md4c.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
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/param.h>
29 #include <sys/systm.h>
30 #include <sys/md4.h>
31 
32 typedef unsigned char *POINTER;
33 typedef uint16_t UINT2;
34 typedef uint32_t UINT4;
35 
36 #define PROTO_LIST(list) list
37 
38 /* Constants for MD4Transform routine.
39  */
40 #define S11 3
41 #define S12 7
42 #define S13 11
43 #define S14 19
44 #define S21 3
45 #define S22 5
46 #define S23 9
47 #define S24 13
48 #define S31 3
49 #define S32 9
50 #define S33 11
51 #define S34 15
52 
53 static void MD4Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
54 static void Encode PROTO_LIST
55   ((unsigned char *, UINT4 *, unsigned int));
56 static void Decode PROTO_LIST
57   ((UINT4 *, const unsigned char *, unsigned int));
58 
59 static unsigned char PADDING[64] = {
60   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
61   0, 0, 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
63 };
64 
65 /* F, G and H are basic MD4 functions.
66  */
67 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
68 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
69 #define H(x, y, z) ((x) ^ (y) ^ (z))
70 
71 /* ROTATE_LEFT rotates x left n bits.
72  */
73 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
74 
75 /* FF, GG and HH are transformations for rounds 1, 2 and 3 */
76 /* Rotation is separate from addition to prevent recomputation */
77 #define FF(a, b, c, d, x, s) { \
78     (a) += F ((b), (c), (d)) + (x); \
79     (a) = ROTATE_LEFT ((a), (s)); \
80   }
81 #define GG(a, b, c, d, x, s) { \
82     (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
83     (a) = ROTATE_LEFT ((a), (s)); \
84   }
85 #define HH(a, b, c, d, x, s) { \
86     (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
87     (a) = ROTATE_LEFT ((a), (s)); \
88   }
89 
90 /* MD4 initialization. Begins an MD4 operation, writing a new context.
91  */
92 void
93 MD4Init(MD4_CTX *context)
94 {
95   context->count[0] = context->count[1] = 0;
96 
97   /* Load magic initialization constants.
98    */
99   context->state[0] = 0x67452301;
100   context->state[1] = 0xefcdab89;
101   context->state[2] = 0x98badcfe;
102   context->state[3] = 0x10325476;
103 }
104 
105 /* MD4 block update operation. Continues an MD4 message-digest
106      operation, processing another message block, and updating the
107      context.
108  */
109 void
110 MD4Update(MD4_CTX *context, const unsigned char *input,
111     unsigned int inputLen)
112 {
113   unsigned int i, index, partLen;
114 
115   /* Compute number of bytes mod 64 */
116   index = (unsigned int)((context->count[0] >> 3) & 0x3F);
117   /* Update number of bits */
118   if ((context->count[0] += ((UINT4)inputLen << 3))
119       < ((UINT4)inputLen << 3))
120     context->count[1]++;
121   context->count[1] += ((UINT4)inputLen >> 29);
122 
123   partLen = 64 - index;
124   /* Transform as many times as possible.
125    */
126   if (inputLen >= partLen) {
127     bcopy(input, &context->buffer[index], partLen);
128     MD4Transform (context->state, context->buffer);
129 
130     for (i = partLen; i + 63 < inputLen; i += 64)
131       MD4Transform (context->state, &input[i]);
132 
133     index = 0;
134   }
135   else
136     i = 0;
137 
138   /* Buffer remaining input */
139   bcopy(&input[i], &context->buffer[index], inputLen-i);
140 }
141 
142 /* MD4 padding. */
143 void
144 MD4Pad(MD4_CTX *context)
145 {
146   unsigned char bits[8];
147   unsigned int index, padLen;
148 
149   /* Save number of bits */
150   Encode (bits, context->count, 8);
151 
152   /* Pad out to 56 mod 64.
153    */
154   index = (unsigned int)((context->count[0] >> 3) & 0x3f);
155   padLen = (index < 56) ? (56 - index) : (120 - index);
156   MD4Update (context, PADDING, padLen);
157 
158   /* Append length (before padding) */
159   MD4Update (context, bits, 8);
160 }
161 
162 /* MD4 finalization. Ends an MD4 message-digest operation, writing the
163      the message digest and zeroizing the context.
164  */
165 void
166 MD4Final(unsigned char digest[static 16], MD4_CTX *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(context, sizeof (*context));
177 }
178 
179 /* MD4 basic transformation. Transforms state based on block.
180  */
181 static void
182 MD4Transform(UINT4 state[4], const unsigned char block[64])
183 {
184   UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
185 
186   Decode (x, block, 64);
187 
188   /* Round 1 */
189   FF (a, b, c, d, x[ 0], S11); /* 1 */
190   FF (d, a, b, c, x[ 1], S12); /* 2 */
191   FF (c, d, a, b, x[ 2], S13); /* 3 */
192   FF (b, c, d, a, x[ 3], S14); /* 4 */
193   FF (a, b, c, d, x[ 4], S11); /* 5 */
194   FF (d, a, b, c, x[ 5], S12); /* 6 */
195   FF (c, d, a, b, x[ 6], S13); /* 7 */
196   FF (b, c, d, a, x[ 7], S14); /* 8 */
197   FF (a, b, c, d, x[ 8], S11); /* 9 */
198   FF (d, a, b, c, x[ 9], S12); /* 10 */
199   FF (c, d, a, b, x[10], S13); /* 11 */
200   FF (b, c, d, a, x[11], S14); /* 12 */
201   FF (a, b, c, d, x[12], S11); /* 13 */
202   FF (d, a, b, c, x[13], S12); /* 14 */
203   FF (c, d, a, b, x[14], S13); /* 15 */
204   FF (b, c, d, a, x[15], S14); /* 16 */
205 
206   /* Round 2 */
207   GG (a, b, c, d, x[ 0], S21); /* 17 */
208   GG (d, a, b, c, x[ 4], S22); /* 18 */
209   GG (c, d, a, b, x[ 8], S23); /* 19 */
210   GG (b, c, d, a, x[12], S24); /* 20 */
211   GG (a, b, c, d, x[ 1], S21); /* 21 */
212   GG (d, a, b, c, x[ 5], S22); /* 22 */
213   GG (c, d, a, b, x[ 9], S23); /* 23 */
214   GG (b, c, d, a, x[13], S24); /* 24 */
215   GG (a, b, c, d, x[ 2], S21); /* 25 */
216   GG (d, a, b, c, x[ 6], S22); /* 26 */
217   GG (c, d, a, b, x[10], S23); /* 27 */
218   GG (b, c, d, a, x[14], S24); /* 28 */
219   GG (a, b, c, d, x[ 3], S21); /* 29 */
220   GG (d, a, b, c, x[ 7], S22); /* 30 */
221   GG (c, d, a, b, x[11], S23); /* 31 */
222   GG (b, c, d, a, x[15], S24); /* 32 */
223 
224   /* Round 3 */
225   HH (a, b, c, d, x[ 0], S31); /* 33 */
226   HH (d, a, b, c, x[ 8], S32); /* 34 */
227   HH (c, d, a, b, x[ 4], S33); /* 35 */
228   HH (b, c, d, a, x[12], S34); /* 36 */
229   HH (a, b, c, d, x[ 2], S31); /* 37 */
230   HH (d, a, b, c, x[10], S32); /* 38 */
231   HH (c, d, a, b, x[ 6], S33); /* 39 */
232   HH (b, c, d, a, x[14], S34); /* 40 */
233   HH (a, b, c, d, x[ 1], S31); /* 41 */
234   HH (d, a, b, c, x[ 9], S32); /* 42 */
235   HH (c, d, a, b, x[ 5], S33); /* 43 */
236   HH (b, c, d, a, x[13], S34); /* 44 */
237   HH (a, b, c, d, x[ 3], S31); /* 45 */
238   HH (d, a, b, c, x[11], S32); /* 46 */
239   HH (c, d, a, b, x[ 7], S33); /* 47 */
240   HH (b, c, d, a, x[15], S34); /* 48 */
241 
242   state[0] += a;
243   state[1] += b;
244   state[2] += c;
245   state[3] += d;
246 
247   /* Zeroize sensitive information.
248    */
249   bzero((POINTER)x, sizeof (x));
250 }
251 
252 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
253      a multiple of 4.
254  */
255 static void
256 Encode(unsigned char *output, UINT4 *input, unsigned int len)
257 {
258   unsigned int i, j;
259 
260   for (i = 0, j = 0; j < len; i++, j += 4) {
261     output[j] = (unsigned char)(input[i] & 0xff);
262     output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
263     output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
264     output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
265   }
266 }
267 
268 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
269      a multiple of 4.
270  */
271 static void
272 Decode(UINT4 *output, const unsigned char *input, unsigned int len)
273 {
274   unsigned int i, j;
275 
276   for (i = 0, j = 0; j < len; i++, j += 4)
277     output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
278       (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
279 }
280