xref: /freebsd/sys/kern/md4c.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /* MD4C.C - RSA Data Security, Inc., MD4 message-digest algorithm
2  */
3 
4 /* Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
5 
6    License to copy and use this software is granted provided that it
7    is identified as the "RSA Data Security, Inc. MD4 Message-Digest
8    Algorithm" in all material mentioning or referencing this software
9    or this function.
10 
11    License is also granted to make and use derivative works provided
12    that such works are identified as "derived from the RSA Data
13    Security, Inc. MD4 Message-Digest Algorithm" in all material
14    mentioning or referencing the derived work.
15 
16    RSA Data Security, Inc. makes no representations concerning either
17    the merchantability of this software or the suitability of this
18    software for any particular purpose. It is provided "as is"
19    without express or implied warranty of any kind.
20 
21    These notices must be retained in any copies of any part of this
22    documentation and/or software.
23  */
24 
25 #include <sys/cdefs.h>
26 __FBSDID("$FreeBSD$");
27 
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/md4.h>
31 
32 typedef unsigned char *POINTER;
33 typedef u_int16_t UINT2;
34 typedef u_int32_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 MD4Init (context)
93 MD4_CTX *context;                                        /* 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 MD4Update (context, input, inputLen)
110 MD4_CTX *context;                                        /* context */
111 const unsigned char *input;                                /* input block */
112 unsigned int inputLen;                     /* length of input block */
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 MD4Pad (context)
145 MD4_CTX *context;                                        /* 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 MD4Final (digest, context)
167 unsigned char digest[16];                         /* message digest */
168 MD4_CTX *context;                                        /* context */
169 {
170   /* Do padding */
171   MD4Pad (context);
172 
173   /* Store state in digest */
174   Encode (digest, context->state, 16);
175 
176   /* Zeroize sensitive information.
177    */
178   bzero((POINTER)context, sizeof (*context));
179 }
180 
181 /* MD4 basic transformation. Transforms state based on block.
182  */
183 static void MD4Transform (state, block)
184 UINT4 state[4];
185 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 Encode (output, input, len)
259 unsigned char *output;
260 UINT4 *input;
261 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  */
276 static void Decode (output, input, len)
277 
278 UINT4 *output;
279 const unsigned char *input;
280 unsigned int len;
281 {
282   unsigned int i, j;
283 
284   for (i = 0, j = 0; j < len; i++, j += 4)
285     output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
286       (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
287 }
288