2 * Copyright (c) 2014 The FreeBSD Foundation
5 * This software was developed by Edward Tomasz Napierala under sponsorship
6 * from the FreeBSD Foundation.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
36 #include <netinet/in.h>
38 #include <openssl/err.h>
39 #include <openssl/md5.h>
40 #include <openssl/rand.h>
45 chap_compute_md5(const char id, const char *secret,
46 const void *challenge, size_t challenge_len, void *response,
52 assert(response_len == MD5_DIGEST_LENGTH);
55 MD5_Update(&ctx, &id, sizeof(id));
56 MD5_Update(&ctx, secret, strlen(secret));
57 MD5_Update(&ctx, challenge, challenge_len);
58 rv = MD5_Final(response, &ctx);
60 log_errx(1, "MD5_Final");
64 chap_hex2int(const char hex)
111 chap_b642bin(const char *b64, void **binp, size_t *bin_lenp)
114 int b64_len, bin_len;
116 b64_len = strlen(b64);
117 bin_len = (b64_len + 3) / 4 * 3;
118 bin = calloc(bin_len, 1);
120 log_err(1, "calloc");
122 bin_len = b64_pton(b64, bin, bin_len);
124 log_warnx("malformed base64 variable");
134 * XXX: Review this _carefully_.
137 chap_hex2bin(const char *hex, void **binp, size_t *bin_lenp)
139 int i, hex_len, nibble;
140 bool lo = true; /* As opposed to 'hi'. */
142 size_t bin_off, bin_len;
144 if (strncasecmp(hex, "0b", strlen("0b")) == 0)
145 return (chap_b642bin(hex + 2, binp, bin_lenp));
147 if (strncasecmp(hex, "0x", strlen("0x")) != 0) {
148 log_warnx("malformed variable, should start with \"0x\""
154 hex_len = strlen(hex);
156 log_warnx("malformed variable; doesn't contain anything "
161 bin_len = hex_len / 2 + hex_len % 2;
162 bin = calloc(bin_len, 1);
164 log_err(1, "calloc");
166 bin_off = bin_len - 1;
167 for (i = hex_len - 1; i >= 0; i--) {
168 nibble = chap_hex2int(hex[i]);
170 log_warnx("malformed variable, invalid char \"%c\"",
176 assert(bin_off < bin_len);
178 bin[bin_off] = nibble;
181 bin[bin_off] |= nibble << 4;
194 chap_bin2hex(const char *bin, size_t bin_len)
196 unsigned char *b64, *tmp;
199 b64_len = (bin_len + 2) / 3 * 4 + 3; /* +2 for "0b", +1 for '\0'. */
200 b64 = malloc(b64_len);
202 log_err(1, "malloc");
205 tmp += sprintf(tmp, "0b");
206 b64_ntop(bin, bin_len, tmp, b64_len - 2);
212 chap_bin2hex(const char *bin, size_t bin_len)
214 unsigned char *hex, *tmp, ch;
218 hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */
219 hex = malloc(hex_len);
221 log_err(1, "malloc");
224 tmp += sprintf(tmp, "0x");
225 for (i = 0; i < bin_len; i++) {
227 tmp += sprintf(tmp, "%02x", ch);
232 #endif /* !USE_BASE64 */
240 chap = calloc(sizeof(*chap), 1);
242 log_err(1, "calloc");
245 * Generate the challenge.
247 rv = RAND_bytes(chap->chap_challenge, sizeof(chap->chap_challenge));
249 log_errx(1, "RAND_bytes failed: %s",
250 ERR_error_string(ERR_get_error(), NULL));
252 rv = RAND_bytes(&chap->chap_id, sizeof(chap->chap_id));
254 log_errx(1, "RAND_bytes failed: %s",
255 ERR_error_string(ERR_get_error(), NULL));
262 chap_get_id(const struct chap *chap)
267 ret = asprintf(&chap_i, "%d", chap->chap_id);
269 log_err(1, "asprintf");
275 chap_get_challenge(const struct chap *chap)
279 chap_c = chap_bin2hex(chap->chap_challenge,
280 sizeof(chap->chap_challenge));
286 chap_receive_bin(struct chap *chap, void *response, size_t response_len)
289 if (response_len != sizeof(chap->chap_response)) {
290 log_debugx("got CHAP response with invalid length; "
291 "got %zd, should be %zd",
292 response_len, sizeof(chap->chap_response));
296 memcpy(chap->chap_response, response, response_len);
301 chap_receive(struct chap *chap, const char *response)
304 size_t response_bin_len;
307 error = chap_hex2bin(response, &response_bin, &response_bin_len);
309 log_debugx("got incorrectly encoded CHAP response \"%s\"",
314 error = chap_receive_bin(chap, response_bin, response_bin_len);
321 chap_authenticate(struct chap *chap, const char *secret)
323 char expected_response[MD5_DIGEST_LENGTH];
325 chap_compute_md5(chap->chap_id, secret,
326 chap->chap_challenge, sizeof(chap->chap_challenge),
327 expected_response, sizeof(expected_response));
329 if (memcmp(chap->chap_response,
330 expected_response, sizeof(expected_response)) != 0) {
338 chap_delete(struct chap *chap)
345 rchap_new(const char *secret)
349 rchap = calloc(sizeof(*rchap), 1);
351 log_err(1, "calloc");
353 rchap->rchap_secret = checked_strdup(secret);
359 rchap_receive_bin(struct rchap *rchap, const unsigned char id,
360 const void *challenge, size_t challenge_len)
363 rchap->rchap_id = id;
364 rchap->rchap_challenge = calloc(challenge_len, 1);
365 if (rchap->rchap_challenge == NULL)
366 log_err(1, "calloc");
367 memcpy(rchap->rchap_challenge, challenge, challenge_len);
368 rchap->rchap_challenge_len = challenge_len;
372 rchap_receive(struct rchap *rchap, const char *id, const char *challenge)
374 unsigned char id_bin;
376 size_t challenge_bin_len;
380 id_bin = strtoul(id, NULL, 10);
382 error = chap_hex2bin(challenge, &challenge_bin, &challenge_bin_len);
384 log_debugx("got incorrectly encoded CHAP challenge \"%s\"",
389 rchap_receive_bin(rchap, id_bin, challenge_bin, challenge_bin_len);
396 rchap_get_response_bin(struct rchap *rchap,
397 void **responsep, size_t *response_lenp)
400 size_t response_bin_len = MD5_DIGEST_LENGTH;
402 response_bin = calloc(response_bin_len, 1);
403 if (response_bin == NULL)
404 log_err(1, "calloc");
406 chap_compute_md5(rchap->rchap_id, rchap->rchap_secret,
407 rchap->rchap_challenge, rchap->rchap_challenge_len,
408 response_bin, response_bin_len);
410 *responsep = response_bin;
411 *response_lenp = response_bin_len;
415 rchap_get_response(struct rchap *rchap)
421 rchap_get_response_bin(rchap, &response, &response_len);
422 chap_r = chap_bin2hex(response, response_len);
429 rchap_delete(struct rchap *rchap)
432 free(rchap->rchap_secret);
433 free(rchap->rchap_challenge);