1 /*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to cifs_MD5_init, call cifs_MD5_update as
14 * needed on buffers full of bytes, and then call cifs_MD5_final, which
15 * will fill a supplied 16-byte array with the digest.
16 */
17
18 /* This code slightly modified to fit into Samba by
19 abartlet@samba.org Jun 2001
20 and to fit the cifs vfs by
21 Steve French sfrench@us.ibm.com */
22
23 #include <linux/string.h>
24 #include "md5.h"
25
26 static void MD5Transform(__u32 buf[4], __u32 const in[16]);
27
28 /*
29 * Note: this code is harmless on little-endian machines.
30 */
31 static void
byteReverse(unsigned char * buf,unsigned longs)32 byteReverse(unsigned char *buf, unsigned longs)
33 {
34 __u32 t;
35 do {
36 t = (__u32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
37 ((unsigned) buf[1] << 8 | buf[0]);
38 *(__u32 *) buf = t;
39 buf += 4;
40 } while (--longs);
41 }
42
43 /*
44 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
45 * initialization constants.
46 */
47 void
cifs_MD5_init(struct MD5Context * ctx)48 cifs_MD5_init(struct MD5Context *ctx)
49 {
50 ctx->buf[0] = 0x67452301;
51 ctx->buf[1] = 0xefcdab89;
52 ctx->buf[2] = 0x98badcfe;
53 ctx->buf[3] = 0x10325476;
54
55 ctx->bits[0] = 0;
56 ctx->bits[1] = 0;
57 }
58
59 /*
60 * Update context to reflect the concatenation of another buffer full
61 * of bytes.
62 */
63 void
cifs_MD5_update(struct MD5Context * ctx,unsigned char const * buf,unsigned len)64 cifs_MD5_update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
65 {
66 register __u32 t;
67
68 /* Update bitcount */
69
70 t = ctx->bits[0];
71 if ((ctx->bits[0] = t + ((__u32) len << 3)) < t)
72 ctx->bits[1]++; /* Carry from low to high */
73 ctx->bits[1] += len >> 29;
74
75 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
76
77 /* Handle any leading odd-sized chunks */
78
79 if (t) {
80 unsigned char *p = (unsigned char *) ctx->in + t;
81
82 t = 64 - t;
83 if (len < t) {
84 memmove(p, buf, len);
85 return;
86 }
87 memmove(p, buf, t);
88 byteReverse(ctx->in, 16);
89 MD5Transform(ctx->buf, (__u32 *) ctx->in);
90 buf += t;
91 len -= t;
92 }
93 /* Process data in 64-byte chunks */
94
95 while (len >= 64) {
96 memmove(ctx->in, buf, 64);
97 byteReverse(ctx->in, 16);
98 MD5Transform(ctx->buf, (__u32 *) ctx->in);
99 buf += 64;
100 len -= 64;
101 }
102
103 /* Handle any remaining bytes of data. */
104
105 memmove(ctx->in, buf, len);
106 }
107
108 /*
109 * Final wrapup - pad to 64-byte boundary with the bit pattern
110 * 1 0* (64-bit count of bits processed, MSB-first)
111 */
112 void
cifs_MD5_final(unsigned char digest[16],struct MD5Context * ctx)113 cifs_MD5_final(unsigned char digest[16], struct MD5Context *ctx)
114 {
115 unsigned int count;
116 unsigned char *p;
117
118 /* Compute number of bytes mod 64 */
119 count = (ctx->bits[0] >> 3) & 0x3F;
120
121 /* Set the first char of padding to 0x80. This is safe since there is
122 always at least one byte free */
123 p = ctx->in + count;
124 *p++ = 0x80;
125
126 /* Bytes of padding needed to make 64 bytes */
127 count = 64 - 1 - count;
128
129 /* Pad out to 56 mod 64 */
130 if (count < 8) {
131 /* Two lots of padding: Pad the first block to 64 bytes */
132 memset(p, 0, count);
133 byteReverse(ctx->in, 16);
134 MD5Transform(ctx->buf, (__u32 *) ctx->in);
135
136 /* Now fill the next block with 56 bytes */
137 memset(ctx->in, 0, 56);
138 } else {
139 /* Pad block to 56 bytes */
140 memset(p, 0, count - 8);
141 }
142 byteReverse(ctx->in, 14);
143
144 /* Append length in bits and transform */
145 ((__u32 *) ctx->in)[14] = ctx->bits[0];
146 ((__u32 *) ctx->in)[15] = ctx->bits[1];
147
148 MD5Transform(ctx->buf, (__u32 *) ctx->in);
149 byteReverse((unsigned char *) ctx->buf, 4);
150 memmove(digest, ctx->buf, 16);
151 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
152 }
153
154 /* The four core functions - F1 is optimized somewhat */
155
156 /* #define F1(x, y, z) (x & y | ~x & z) */
157 #define F1(x, y, z) (z ^ (x & (y ^ z)))
158 #define F2(x, y, z) F1(z, x, y)
159 #define F3(x, y, z) (x ^ y ^ z)
160 #define F4(x, y, z) (y ^ (x | ~z))
161
162 /* This is the central step in the MD5 algorithm. */
163 #define MD5STEP(f, w, x, y, z, data, s) \
164 (w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x)
165
166 /*
167 * The core of the MD5 algorithm, this alters an existing MD5 hash to
168 * reflect the addition of 16 longwords of new data. cifs_MD5_update blocks
169 * the data and converts bytes into longwords for this routine.
170 */
171 static void
MD5Transform(__u32 buf[4],__u32 const in[16])172 MD5Transform(__u32 buf[4], __u32 const in[16])
173 {
174 register __u32 a, b, c, d;
175
176 a = buf[0];
177 b = buf[1];
178 c = buf[2];
179 d = buf[3];
180
181 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
182 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
183 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
184 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
185 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
186 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
187 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
188 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
189 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
190 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
191 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
192 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
193 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
194 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
195 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
196 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
197
198 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
199 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
200 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
201 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
202 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
203 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
204 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
205 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
206 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
207 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
208 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
209 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
210 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
211 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
212 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
213 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
214
215 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
216 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
217 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
218 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
219 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
220 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
221 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
222 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
223 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
224 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
225 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
226 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
227 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
228 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
229 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
230 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
231
232 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
233 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
234 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
235 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
236 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
237 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
238 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
239 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
240 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
241 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
242 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
243 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
244 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
245 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
246 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
247 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
248
249 buf[0] += a;
250 buf[1] += b;
251 buf[2] += c;
252 buf[3] += d;
253 }
254
255 #if 0 /* currently unused */
256 /***********************************************************************
257 the rfc 2104 version of hmac_md5 initialisation.
258 ***********************************************************************/
259 static void
260 hmac_md5_init_rfc2104(unsigned char *key, int key_len,
261 struct HMACMD5Context *ctx)
262 {
263 int i;
264
265 /* if key is longer than 64 bytes reset it to key=MD5(key) */
266 if (key_len > 64) {
267 unsigned char tk[16];
268 struct MD5Context tctx;
269
270 cifs_MD5_init(&tctx);
271 cifs_MD5_update(&tctx, key, key_len);
272 cifs_MD5_final(tk, &tctx);
273
274 key = tk;
275 key_len = 16;
276 }
277
278 /* start out by storing key in pads */
279 memset(ctx->k_ipad, 0, sizeof(ctx->k_ipad));
280 memset(ctx->k_opad, 0, sizeof(ctx->k_opad));
281 memcpy(ctx->k_ipad, key, key_len);
282 memcpy(ctx->k_opad, key, key_len);
283
284 /* XOR key with ipad and opad values */
285 for (i = 0; i < 64; i++) {
286 ctx->k_ipad[i] ^= 0x36;
287 ctx->k_opad[i] ^= 0x5c;
288 }
289
290 cifs_MD5_init(&ctx->ctx);
291 cifs_MD5_update(&ctx->ctx, ctx->k_ipad, 64);
292 }
293 #endif
294
295 /***********************************************************************
296 the microsoft version of hmac_md5 initialisation.
297 ***********************************************************************/
298 void
hmac_md5_init_limK_to_64(const unsigned char * key,int key_len,struct HMACMD5Context * ctx)299 hmac_md5_init_limK_to_64(const unsigned char *key, int key_len,
300 struct HMACMD5Context *ctx)
301 {
302 int i;
303
304 /* if key is longer than 64 bytes truncate it */
305 if (key_len > 64)
306 key_len = 64;
307
308 /* start out by storing key in pads */
309 memset(ctx->k_ipad, 0, sizeof(ctx->k_ipad));
310 memset(ctx->k_opad, 0, sizeof(ctx->k_opad));
311 memcpy(ctx->k_ipad, key, key_len);
312 memcpy(ctx->k_opad, key, key_len);
313
314 /* XOR key with ipad and opad values */
315 for (i = 0; i < 64; i++) {
316 ctx->k_ipad[i] ^= 0x36;
317 ctx->k_opad[i] ^= 0x5c;
318 }
319
320 cifs_MD5_init(&ctx->ctx);
321 cifs_MD5_update(&ctx->ctx, ctx->k_ipad, 64);
322 }
323
324 /***********************************************************************
325 update hmac_md5 "inner" buffer
326 ***********************************************************************/
327 void
hmac_md5_update(const unsigned char * text,int text_len,struct HMACMD5Context * ctx)328 hmac_md5_update(const unsigned char *text, int text_len,
329 struct HMACMD5Context *ctx)
330 {
331 cifs_MD5_update(&ctx->ctx, text, text_len); /* then text of datagram */
332 }
333
334 /***********************************************************************
335 finish off hmac_md5 "inner" buffer and generate outer one.
336 ***********************************************************************/
337 void
hmac_md5_final(unsigned char * digest,struct HMACMD5Context * ctx)338 hmac_md5_final(unsigned char *digest, struct HMACMD5Context *ctx)
339 {
340 struct MD5Context ctx_o;
341
342 cifs_MD5_final(digest, &ctx->ctx);
343
344 cifs_MD5_init(&ctx_o);
345 cifs_MD5_update(&ctx_o, ctx->k_opad, 64);
346 cifs_MD5_update(&ctx_o, digest, 16);
347 cifs_MD5_final(digest, &ctx_o);
348 }
349
350 /***********************************************************
351 single function to calculate an HMAC MD5 digest from data.
352 use the microsoft hmacmd5 init method because the key is 16 bytes.
353 ************************************************************/
354 #if 0 /* currently unused */
355 static void
356 hmac_md5(unsigned char key[16], unsigned char *data, int data_len,
357 unsigned char *digest)
358 {
359 struct HMACMD5Context ctx;
360 hmac_md5_init_limK_to_64(key, 16, &ctx);
361 if (data_len != 0)
362 hmac_md5_update(data, data_len, &ctx);
363
364 hmac_md5_final(digest, &ctx);
365 }
366 #endif
367