2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2014 The FreeBSD Foundation
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include <netinet/in.h>
38 #include "libiscsiutil.h"
41 chap_compute_md5(const char id, const char *secret,
42 const void *challenge, size_t challenge_len, void *response,
47 assert(response_len == CHAP_DIGEST_LEN);
50 MD5Update(&ctx, &id, sizeof(id));
51 MD5Update(&ctx, secret, strlen(secret));
52 MD5Update(&ctx, challenge, challenge_len);
53 MD5Final(response, &ctx);
57 chap_hex2int(const char hex)
104 chap_b642bin(const char *b64, void **binp, size_t *bin_lenp)
107 int b64_len, bin_len;
109 b64_len = strlen(b64);
110 bin_len = (b64_len + 3) / 4 * 3;
111 bin = calloc(bin_len, 1);
113 log_err(1, "calloc");
115 bin_len = b64_pton(b64, bin, bin_len);
117 log_warnx("malformed base64 variable");
127 * XXX: Review this _carefully_.
130 chap_hex2bin(const char *hex, void **binp, size_t *bin_lenp)
132 int i, hex_len, nibble;
133 bool lo = true; /* As opposed to 'hi'. */
135 size_t bin_off, bin_len;
137 if (strncasecmp(hex, "0b", strlen("0b")) == 0)
138 return (chap_b642bin(hex + 2, binp, bin_lenp));
140 if (strncasecmp(hex, "0x", strlen("0x")) != 0) {
141 log_warnx("malformed variable, should start with \"0x\""
147 hex_len = strlen(hex);
149 log_warnx("malformed variable; doesn't contain anything "
154 bin_len = hex_len / 2 + hex_len % 2;
155 bin = calloc(bin_len, 1);
157 log_err(1, "calloc");
159 bin_off = bin_len - 1;
160 for (i = hex_len - 1; i >= 0; i--) {
161 nibble = chap_hex2int(hex[i]);
163 log_warnx("malformed variable, invalid char \"%c\"",
169 assert(bin_off < bin_len);
171 bin[bin_off] = nibble;
174 bin[bin_off] |= nibble << 4;
187 chap_bin2hex(const char *bin, size_t bin_len)
189 unsigned char *b64, *tmp;
192 b64_len = (bin_len + 2) / 3 * 4 + 3; /* +2 for "0b", +1 for '\0'. */
193 b64 = malloc(b64_len);
195 log_err(1, "malloc");
198 tmp += sprintf(tmp, "0b");
199 b64_ntop(bin, bin_len, tmp, b64_len - 2);
205 chap_bin2hex(const char *bin, size_t bin_len)
207 unsigned char *hex, *tmp, ch;
211 hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */
212 hex = malloc(hex_len);
214 log_err(1, "malloc");
217 tmp += sprintf(tmp, "0x");
218 for (i = 0; i < bin_len; i++) {
220 tmp += sprintf(tmp, "%02x", ch);
225 #endif /* !USE_BASE64 */
232 chap = calloc(1, sizeof(*chap));
234 log_err(1, "calloc");
237 * Generate the challenge.
239 arc4random_buf(chap->chap_challenge, sizeof(chap->chap_challenge));
240 arc4random_buf(&chap->chap_id, sizeof(chap->chap_id));
246 chap_get_id(const struct chap *chap)
251 ret = asprintf(&chap_i, "%d", chap->chap_id);
253 log_err(1, "asprintf");
259 chap_get_challenge(const struct chap *chap)
263 chap_c = chap_bin2hex(chap->chap_challenge,
264 sizeof(chap->chap_challenge));
270 chap_receive_bin(struct chap *chap, void *response, size_t response_len)
273 if (response_len != sizeof(chap->chap_response)) {
274 log_debugx("got CHAP response with invalid length; "
275 "got %zd, should be %zd",
276 response_len, sizeof(chap->chap_response));
280 memcpy(chap->chap_response, response, response_len);
285 chap_receive(struct chap *chap, const char *response)
288 size_t response_bin_len;
291 error = chap_hex2bin(response, &response_bin, &response_bin_len);
293 log_debugx("got incorrectly encoded CHAP response \"%s\"",
298 error = chap_receive_bin(chap, response_bin, response_bin_len);
305 chap_authenticate(struct chap *chap, const char *secret)
307 char expected_response[CHAP_DIGEST_LEN];
309 chap_compute_md5(chap->chap_id, secret,
310 chap->chap_challenge, sizeof(chap->chap_challenge),
311 expected_response, sizeof(expected_response));
313 if (memcmp(chap->chap_response,
314 expected_response, sizeof(expected_response)) != 0) {
322 chap_delete(struct chap *chap)
329 rchap_new(const char *secret)
333 rchap = calloc(1, sizeof(*rchap));
335 log_err(1, "calloc");
337 rchap->rchap_secret = checked_strdup(secret);
343 rchap_receive_bin(struct rchap *rchap, const unsigned char id,
344 const void *challenge, size_t challenge_len)
347 rchap->rchap_id = id;
348 rchap->rchap_challenge = calloc(challenge_len, 1);
349 if (rchap->rchap_challenge == NULL)
350 log_err(1, "calloc");
351 memcpy(rchap->rchap_challenge, challenge, challenge_len);
352 rchap->rchap_challenge_len = challenge_len;
356 rchap_receive(struct rchap *rchap, const char *id, const char *challenge)
358 unsigned char id_bin;
360 size_t challenge_bin_len;
364 id_bin = strtoul(id, NULL, 10);
366 error = chap_hex2bin(challenge, &challenge_bin, &challenge_bin_len);
368 log_debugx("got incorrectly encoded CHAP challenge \"%s\"",
373 rchap_receive_bin(rchap, id_bin, challenge_bin, challenge_bin_len);
380 rchap_get_response_bin(struct rchap *rchap,
381 void **responsep, size_t *response_lenp)
384 size_t response_bin_len = CHAP_DIGEST_LEN;
386 response_bin = calloc(response_bin_len, 1);
387 if (response_bin == NULL)
388 log_err(1, "calloc");
390 chap_compute_md5(rchap->rchap_id, rchap->rchap_secret,
391 rchap->rchap_challenge, rchap->rchap_challenge_len,
392 response_bin, response_bin_len);
394 *responsep = response_bin;
395 *response_lenp = response_bin_len;
399 rchap_get_response(struct rchap *rchap)
405 rchap_get_response_bin(rchap, &response, &response_len);
406 chap_r = chap_bin2hex(response, response_len);
413 rchap_delete(struct rchap *rchap)
416 free(rchap->rchap_secret);
417 free(rchap->rchap_challenge);