3 static const char rcsid[] = "$Header: /proj/cvs/prod/bind9/lib/bind/dst/hmac_link.c,v 1.2.2.1.4.2 2006/03/10 00:17:21 marka Exp $";
6 * Portions Copyright (c) 1995-1998 by Trusted Information Systems, Inc.
8 * Permission to use, copy modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
12 * THE SOFTWARE IS PROVIDED "AS IS" AND TRUSTED INFORMATION SYSTEMS
13 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
14 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
15 * TRUSTED INFORMATION SYSTEMS BE LIABLE FOR ANY SPECIAL, DIRECT,
16 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
17 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
18 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
19 * WITH THE USE OR PERFORMANCE OF THE SOFTWARE.
23 * This file contains an implementation of the HMAC-MD5 algorithm.
25 #include "port_before.h"
32 #include <sys/param.h>
34 #include <netinet/in.h>
35 #include <arpa/nameser.h>
38 #include "dst_internal.h"
49 # define _MD5_H_ 1 /* make sure we do not include rsaref md5.h file */
53 #include "port_after.h"
57 #define HMAC_IPAD 0x36
58 #define HMAC_OPAD 0x5c
62 typedef struct hmackey {
63 u_char hk_ipad[64], hk_opad[64];
67 /**************************************************************************
69 * Call HMAC signing functions to sign a block of data.
70 * There are three steps to signing, INIT (initialize structures),
71 * UPDATE (hash (more) data), FINAL (generate a signature). This
72 * routine performs one or more of these steps.
74 * mode SIG_MODE_INIT, SIG_MODE_UPDATE and/or SIG_MODE_FINAL.
75 * priv_key key to use for signing.
76 * context the context to be used in this digest
77 * data data to be signed.
78 * len length in bytes of data.
79 * signature location to store signature.
80 * sig_len size of the signature location
82 * N Success on SIG_MODE_FINAL = returns signature length in bytes
83 * 0 Success on SIG_MODE_INIT and UPDATE
88 dst_hmac_md5_sign(const int mode, DST_KEY *d_key, void **context,
89 const u_char *data, const int len,
90 u_char *signature, const int sig_len)
96 if (d_key == NULL || d_key->dk_KEY_struct == NULL)
99 if (mode & SIG_MODE_INIT)
100 ctx = (MD5_CTX *) malloc(sizeof(*ctx));
102 ctx = (MD5_CTX *) *context;
106 key = (HMAC_Key *) d_key->dk_KEY_struct;
108 if (mode & SIG_MODE_INIT) {
110 MD5Update(ctx, key->hk_ipad, HMAC_LEN);
113 if ((mode & SIG_MODE_UPDATE) && (data && len > 0))
114 MD5Update(ctx, data, len);
116 if (mode & SIG_MODE_FINAL) {
117 if (signature == NULL || sig_len < MD5_LEN)
118 return (SIGN_FINAL_FAILURE);
119 MD5Final(signature, ctx);
121 /* perform outer MD5 */
123 MD5Update(ctx, key->hk_opad, HMAC_LEN);
124 MD5Update(ctx, signature, MD5_LEN);
125 MD5Final(signature, ctx);
132 *context = (void *) ctx;
138 /**************************************************************************
139 * dst_hmac_md5_verify()
140 * Calls HMAC verification routines. There are three steps to
141 * verification, INIT (initialize structures), UPDATE (hash (more) data),
142 * FINAL (generate a signature). This routine performs one or more of
145 * mode SIG_MODE_INIT, SIG_MODE_UPDATE and/or SIG_MODE_FINAL.
146 * dkey key to use for verify.
148 * len length in bytes of data.
149 * signature signature.
150 * sig_len length in bytes of signature.
157 dst_hmac_md5_verify(const int mode, DST_KEY *d_key, void **context,
158 const u_char *data, const int len,
159 const u_char *signature, const int sig_len)
164 if (d_key == NULL || d_key->dk_KEY_struct == NULL)
167 if (mode & SIG_MODE_INIT)
168 ctx = (MD5_CTX *) malloc(sizeof(*ctx));
170 ctx = (MD5_CTX *) *context;
174 key = (HMAC_Key *) d_key->dk_KEY_struct;
175 if (mode & SIG_MODE_INIT) {
177 MD5Update(ctx, key->hk_ipad, HMAC_LEN);
179 if ((mode & SIG_MODE_UPDATE) && (data && len > 0))
180 MD5Update(ctx, data, len);
182 if (mode & SIG_MODE_FINAL) {
183 u_char digest[MD5_LEN];
184 if (signature == NULL || key == NULL || sig_len != MD5_LEN)
185 return (VERIFY_FINAL_FAILURE);
186 MD5Final(digest, ctx);
188 /* perform outer MD5 */
190 MD5Update(ctx, key->hk_opad, HMAC_LEN);
191 MD5Update(ctx, digest, MD5_LEN);
192 MD5Final(digest, ctx);
195 if (memcmp(digest, signature, MD5_LEN) != 0)
196 return (VERIFY_FINAL_FAILURE);
201 *context = (void *) ctx;
207 /**************************************************************************
208 * dst_buffer_to_hmac_md5
209 * Converts key from raw data to an HMAC Key
210 * This function gets in a pointer to the data
212 * hkey the HMAC key to be filled in
213 * key the key in raw format
214 * keylen the length of the key
220 dst_buffer_to_hmac_md5(DST_KEY *dkey, const u_char *key, const int keylen)
223 HMAC_Key *hkey = NULL;
225 int local_keylen = keylen;
227 if (dkey == NULL || key == NULL || keylen < 0)
230 if ((hkey = (HMAC_Key *) malloc(sizeof(HMAC_Key))) == NULL)
233 memset(hkey->hk_ipad, 0, sizeof(hkey->hk_ipad));
234 memset(hkey->hk_opad, 0, sizeof(hkey->hk_opad));
236 /* if key is longer than HMAC_LEN bytes reset it to key=MD5(key) */
237 if (keylen > HMAC_LEN) {
240 MD5Update(&ctx, key, keylen);
242 memset((void *) &ctx, 0, sizeof(ctx));
244 local_keylen = MD5_LEN;
246 /* start out by storing key in pads */
247 memcpy(hkey->hk_ipad, key, local_keylen);
248 memcpy(hkey->hk_opad, key, local_keylen);
250 /* XOR key with hk_ipad and opad values */
251 for (i = 0; i < HMAC_LEN; i++) {
252 hkey->hk_ipad[i] ^= HMAC_IPAD;
253 hkey->hk_opad[i] ^= HMAC_OPAD;
255 dkey->dk_key_size = local_keylen;
256 dkey->dk_KEY_struct = (void *) hkey;
261 /**************************************************************************
262 * dst_hmac_md5_key_to_file_format
263 * Encodes an HMAC Key into the portable file format.
265 * hkey HMAC KEY structure
267 * buff_len size of output buffer
269 * 0 Failure - null input hkey
270 * -1 Failure - not enough space in output area
271 * N Success - Length of data returned in buff
275 dst_hmac_md5_key_to_file_format(const DST_KEY *dkey, char *buff,
279 int len, b_len, i, key_len;
280 u_char key[HMAC_LEN];
283 if (dkey == NULL || dkey->dk_KEY_struct == NULL)
285 if (buff == NULL || buff_len <= (int) strlen(key_file_fmt_str))
286 return (-1); /* no OR not enough space in output area */
288 hkey = (HMAC_Key *) dkey->dk_KEY_struct;
289 memset(buff, 0, buff_len); /* just in case */
290 /* write file header */
291 sprintf(buff, key_file_fmt_str, KEY_FILE_FORMAT, KEY_HMAC_MD5, "HMAC");
293 bp = buff + strlen(buff);
294 b_len = buff_len - (bp - buff);
296 memset(key, 0, HMAC_LEN);
297 for (i = 0; i < HMAC_LEN; i++)
298 key[i] = hkey->hk_ipad[i] ^ HMAC_IPAD;
299 for (i = HMAC_LEN - 1; i >= 0; i--)
305 bp += strlen("Key: ");
306 b_len = buff_len - (bp - buff);
308 len = b64_ntop(key, key_len, bp, b_len);
314 b_len = buff_len - (bp - buff);
316 return (buff_len - b_len);
320 /**************************************************************************
321 * dst_hmac_md5_key_from_file_format
322 * Converts contents of a key file into an HMAC key.
324 * hkey structure to put key into
325 * buff buffer containing the encoded key
326 * buff_len the length of the buffer
328 * n >= 0 Foot print of the key converted
329 * n < 0 Error in conversion
333 dst_hmac_md5_key_from_file_format(DST_KEY *dkey, const char *buff,
336 const char *p = buff, *eol;
337 u_char key[HMAC_LEN+1]; /* b64_pton needs more than 64 bytes do decode
338 * it should probably be fixed rather than doing
346 if (buff == NULL || buff_len < 0)
349 memset(key, 0, sizeof(key));
351 if (!dst_s_verify_str(&p, "Key: "))
354 eol = strchr(p, '\n');
358 tmp = malloc(len + 2);
363 key_len = b64_pton((char *)tmp, key, HMAC_LEN+1); /* see above */
364 SAFE_FREE2(tmp, len + 2);
366 if (dst_buffer_to_hmac_md5(dkey, key, key_len) < 0) {
373 * dst_hmac_md5_to_dns_key()
374 * function to extract hmac key from DST_KEY structure
376 * in_key: HMAC-MD5 key
378 * out_str: buffer to write ot
379 * out_len: size of output buffer
381 * number of bytes written to output buffer
384 dst_hmac_md5_to_dns_key(const DST_KEY *in_key, u_char *out_str,
391 if (in_key == NULL || in_key->dk_KEY_struct == NULL ||
392 out_len <= in_key->dk_key_size || out_str == NULL)
395 hkey = (HMAC_Key *) in_key->dk_KEY_struct;
396 for (i = 0; i < in_key->dk_key_size; i++)
397 out_str[i] = hkey->hk_ipad[i] ^ HMAC_IPAD;
401 /**************************************************************************
402 * dst_hmac_md5_compare_keys
403 * Compare two keys for equality.
405 * 0 The keys are equal
406 * NON-ZERO The keys are not equal
410 dst_hmac_md5_compare_keys(const DST_KEY *key1, const DST_KEY *key2)
412 HMAC_Key *hkey1 = (HMAC_Key *) key1->dk_KEY_struct;
413 HMAC_Key *hkey2 = (HMAC_Key *) key2->dk_KEY_struct;
414 return memcmp(hkey1->hk_ipad, hkey2->hk_ipad, HMAC_LEN);
417 /**************************************************************************
418 * dst_hmac_md5_free_key_structure
419 * Frees all (none) dynamically allocated structures in hkey
423 dst_hmac_md5_free_key_structure(void *key)
425 HMAC_Key *hkey = key;
431 /***************************************************************************
432 * dst_hmac_md5_generate_key
433 * Creates a HMAC key of size size with a maximum size of 63 bytes
434 * generating a HMAC key larger than 63 bytes makes no sense as that key
435 * is digested before use.
439 dst_hmac_md5_generate_key(DST_KEY *key, const int nothing)
447 * dst_hmac_md5_init() Function to answer set up function pointers for HMAC
457 if (dst_t_func[KEY_HMAC_MD5] != NULL)
459 dst_t_func[KEY_HMAC_MD5] = malloc(sizeof(struct dst_func));
460 if (dst_t_func[KEY_HMAC_MD5] == NULL)
462 memset(dst_t_func[KEY_HMAC_MD5], 0, sizeof(struct dst_func));
463 dst_t_func[KEY_HMAC_MD5]->sign = dst_hmac_md5_sign;
464 dst_t_func[KEY_HMAC_MD5]->verify = dst_hmac_md5_verify;
465 dst_t_func[KEY_HMAC_MD5]->compare = dst_hmac_md5_compare_keys;
466 dst_t_func[KEY_HMAC_MD5]->generate = dst_hmac_md5_generate_key;
467 dst_t_func[KEY_HMAC_MD5]->destroy = dst_hmac_md5_free_key_structure;
468 dst_t_func[KEY_HMAC_MD5]->to_dns_key = dst_hmac_md5_to_dns_key;
469 dst_t_func[KEY_HMAC_MD5]->from_dns_key = dst_buffer_to_hmac_md5;
470 dst_t_func[KEY_HMAC_MD5]->to_file_fmt = dst_hmac_md5_key_to_file_format;
471 dst_t_func[KEY_HMAC_MD5]->from_file_fmt = dst_hmac_md5_key_from_file_format;
476 #define dst_hmac_md5_init __dst_hmac_md5_init