xref: /freebsd/sys/kern/md5c.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
1 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
2  * $FreeBSD$
3  */
4 
5 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
6 rights reserved.
7 
8 License to copy and use this software is granted provided that it
9 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
10 Algorithm" in all material mentioning or referencing this software
11 or this function.
12 
13 License is also granted to make and use derivative works provided
14 that such works are identified as "derived from the RSA Data
15 Security, Inc. MD5 Message-Digest Algorithm" in all material
16 mentioning or referencing the derived work.
17 
18 RSA Data Security, Inc. makes no representations concerning either
19 the merchantability of this software or the suitability of this
20 software for any particular purpose. It is provided "as is"
21 without express or implied warranty of any kind.
22 
23 These notices must be retained in any copies of any part of this
24 documentation and/or software.
25  */
26 
27 #include "md5.h"
28 
29 typedef unsigned char *POINTER;
30 typedef unsigned short int UINT2;
31 typedef unsigned long int UINT4;
32 
33 #define PROTO_LIST(list) list
34 
35 /* Constants for MD5Transform routine.
36  */
37 #define S11 7
38 #define S12 12
39 #define S13 17
40 #define S14 22
41 #define S21 5
42 #define S22 9
43 #define S23 14
44 #define S24 20
45 #define S31 4
46 #define S32 11
47 #define S33 16
48 #define S34 23
49 #define S41 6
50 #define S42 10
51 #define S43 15
52 #define S44 21
53 
54 static void MD5Transform PROTO_LIST ((UINT4 [4], const unsigned char [64]));
55 static void Encode PROTO_LIST
56   ((unsigned char *, UINT4 *, unsigned int));
57 static void Decode PROTO_LIST
58   ((UINT4 *, const unsigned char *, unsigned int));
59 
60 static unsigned char PADDING[64] = {
61   0x80, 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, 0, 0, 0, 0,
63   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
64 };
65 
66 /* F, G, H and I are basic MD5 functions.
67  */
68 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
69 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
70 #define H(x, y, z) ((x) ^ (y) ^ (z))
71 #define I(x, y, z) ((y) ^ ((x) | (~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, HH, and II transformations for rounds 1, 2, 3, and 4.
78 Rotation is separate from addition to prevent recomputation.
79  */
80 #define FF(a, b, c, d, x, s, ac) { \
81  (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
82  (a) = ROTATE_LEFT ((a), (s)); \
83  (a) += (b); \
84   }
85 #define GG(a, b, c, d, x, s, ac) { \
86  (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
87  (a) = ROTATE_LEFT ((a), (s)); \
88  (a) += (b); \
89   }
90 #define HH(a, b, c, d, x, s, ac) { \
91  (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
92  (a) = ROTATE_LEFT ((a), (s)); \
93  (a) += (b); \
94   }
95 #define II(a, b, c, d, x, s, ac) { \
96  (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
97  (a) = ROTATE_LEFT ((a), (s)); \
98  (a) += (b); \
99   }
100 
101 /* MD5 initialization. Begins an MD5 operation, writing a new context.
102  */
103 void MD5Init (context)
104 MD5_CTX *context;                                        /* context */
105 {
106   context->count[0] = context->count[1] = 0;
107   /* Load magic initialization constants.
108 */
109   context->state[0] = 0x67452301;
110   context->state[1] = 0xefcdab89;
111   context->state[2] = 0x98badcfe;
112   context->state[3] = 0x10325476;
113 }
114 
115 /* MD5 block update operation. Continues an MD5 message-digest
116   operation, processing another message block, and updating the
117   context.
118  */
119 void MD5Update (context, input, inputLen)
120 MD5_CTX *context;                                        /* context */
121 const unsigned char *input;                                /* input block */
122 unsigned int inputLen;                     /* length of input block */
123 {
124   unsigned int i, index, partLen;
125 
126   /* Compute number of bytes mod 64 */
127   index = (unsigned int)((context->count[0] >> 3) & 0x3F);
128 
129   /* Update number of bits */
130   if ((context->count[0] += ((UINT4)inputLen << 3))
131    < ((UINT4)inputLen << 3))
132  context->count[1]++;
133   context->count[1] += ((UINT4)inputLen >> 29);
134 
135   partLen = 64 - index;
136 
137   /* Transform as many times as possible.
138 */
139   if (inputLen >= partLen) {
140  memcpy
141    ((POINTER)&context->buffer[index], (POINTER)input, partLen);
142  MD5Transform (context->state, context->buffer);
143 
144  for (i = partLen; i + 63 < inputLen; i += 64)
145    MD5Transform (context->state, &input[i]);
146 
147  index = 0;
148   }
149   else
150  i = 0;
151 
152   /* Buffer remaining input */
153   memcpy
154  ((POINTER)&context->buffer[index], (POINTER)&input[i],
155   inputLen-i);
156 }
157 
158 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
159   the message digest and zeroizing the context.
160  */
161 void MD5Final (digest, context)
162 unsigned char digest[16];                         /* message digest */
163 MD5_CTX *context;                                       /* context */
164 {
165   unsigned char bits[8];
166   unsigned int index, padLen;
167 
168   /* Save number of bits */
169   Encode (bits, context->count, 8);
170 
171   /* Pad out to 56 mod 64.
172 */
173   index = (unsigned int)((context->count[0] >> 3) & 0x3f);
174   padLen = (index < 56) ? (56 - index) : (120 - index);
175   MD5Update (context, PADDING, padLen);
176 
177   /* Append length (before padding) */
178   MD5Update (context, bits, 8);
179   /* Store state in digest */
180   Encode (digest, context->state, 16);
181 
182   /* Zeroize sensitive information.
183 */
184   memset ((POINTER)context, 0, sizeof (*context));
185 }
186 
187 /* MD5 basic transformation. Transforms state based on block.
188  */
189 static void MD5Transform (state, block)
190 UINT4 state[4];
191 const unsigned char block[64];
192 {
193   UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
194 
195   Decode (x, block, 64);
196 
197   /* Round 1 */
198   FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
199   FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
200   FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
201   FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
202   FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
203   FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
204   FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
205   FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
206   FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
207   FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
208   FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
209   FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
210   FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
211   FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
212   FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
213   FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
214 
215  /* Round 2 */
216   GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
217   GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
218   GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
219   GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
220   GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
221   GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
222   GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
223   GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
224   GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
225   GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
226   GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
227   GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
228   GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
229   GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
230   GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
231   GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
232 
233   /* Round 3 */
234   HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
235   HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
236   HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
237   HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
238   HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
239   HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
240   HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
241   HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
242   HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
243   HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
244   HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
245   HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
246   HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
247   HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
248   HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
249   HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
250 
251   /* Round 4 */
252   II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
253   II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
254   II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
255   II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
256   II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
257   II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
258   II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
259   II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
260   II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
261   II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
262   II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
263   II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
264   II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
265   II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
266   II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
267   II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
268 
269   state[0] += a;
270   state[1] += b;
271   state[2] += c;
272   state[3] += d;
273 
274   /* Zeroize sensitive information.
275 */
276   memset ((POINTER)x, 0, sizeof (x));
277 }
278 
279 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
280   a multiple of 4.
281  */
282 static void Encode (output, input, len)
283 unsigned char *output;
284 UINT4 *input;
285 unsigned int len;
286 {
287   unsigned int i, j;
288 
289   for (i = 0, j = 0; j < len; i++, j += 4) {
290  output[j] = (unsigned char)(input[i] & 0xff);
291  output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
292  output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
293  output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
294   }
295 }
296 
297 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
298   a multiple of 4.
299  */
300 static void Decode (output, input, len)
301 UINT4 *output;
302 const unsigned char *input;
303 unsigned int len;
304 {
305   unsigned int i, j;
306 
307   for (i = 0, j = 0; j < len; i++, j += 4)
308  output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
309    (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
310 }
311