6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * Copyright 2002 The FreeRADIUS server project
21 * Copyright 2002 Alan DeKok <aland@ox.org>
33 #include "rad_assert.h"
35 static const char rcsid[] = "$Id$";
37 static int digest_authorize(void *instance, REQUEST *request)
41 /* quiet the compiler */
45 * We need both of these attributes to do the authentication.
47 vp = pairfind(request->packet->vps, PW_DIGEST_RESPONSE);
49 return RLM_MODULE_NOOP;
53 * Check the sanity of the attribute.
55 if (vp->length != 32) {
56 DEBUG("ERROR: Received invalid Digest-Response attribute (length %d should be 32)", vp->length);
57 return RLM_MODULE_INVALID;
63 vp = pairfind(request->packet->vps, PW_DIGEST_ATTRIBUTES);
65 DEBUG("ERROR: Received Digest-Response without Digest-Attributes");
66 return RLM_MODULE_INVALID;
70 * Everything's OK, add a digest authentication type.
72 if (pairfind(request->config_items, PW_AUTHTYPE) == NULL) {
73 DEBUG("rlm_digest: Adding Auth-Type = DIGEST");
74 pairadd(&request->config_items,
75 pairmake("Auth-Type", "DIGEST", T_OP_EQ));
82 * Convert a string in hex to one in binary
84 * FIXME: call lrad_hex2bin
86 static void hex2bin(uint8_t *out, const uint8_t *in)
91 sscanf(in, "%02x", &tmp);
99 * Perform all of the wondrous variants of digest authentication.
101 static int digest_authenticate(void *instance, REQUEST *request)
104 int a1_len, a2_len, kd_len;
105 uint8_t a1[(MAX_STRING_LEN + 1) * 5]; /* can be 5 attributes */
106 uint8_t a2[(MAX_STRING_LEN + 1) * 3]; /* can be 3 attributes */
107 uint8_t kd[(MAX_STRING_LEN + 1) * 5];
108 uint8_t hash[16]; /* MD5 output */
110 VALUE_PAIR *qop, *nonce;
112 instance = instance; /* -Wunused */
115 * We require access to the plain-text password.
117 vp = pairfind(request->config_items, PW_PASSWORD);
119 radlog(L_AUTH, "rlm_digest: Configuration item \"User-Password\" is required for authentication.");
120 return RLM_MODULE_INVALID;
124 * We need these, too.
126 vp = pairfind(request->packet->vps, PW_DIGEST_ATTRIBUTES);
128 DEBUG("ERROR: You set 'Auth-Type = Digest' for a request that did not contain any digest attributes!");
129 return RLM_MODULE_INVALID;
132 * Loop through the Digest-Attributes, sanity checking them.
134 DEBUG(" rlm_digest: Converting Digest-Attributes to something sane...");
136 int length = vp->length;
138 uint8_t *p = &vp->vp_octets[0];
142 * Until this stupidly encoded attribure is exhausted.
146 * The attribute type must be valid
148 if ((p[0] == 0) || (p[0] > 10)) {
149 DEBUG("ERROR: Received Digest-Attributes with invalid sub-attribute %d", p[0]);
150 return RLM_MODULE_INVALID;
153 attrlen = p[1]; /* stupid VSA format */
159 DEBUG("ERROR: Received Digest-Attributes with short sub-attribute %d, of length %d", p[0], attrlen);
160 return RLM_MODULE_INVALID;
166 if (attrlen > length) {
167 DEBUG("ERROR: Received Digest-Attributes with long sub-attribute %d, of length %d", p[0], attrlen);
168 return RLM_MODULE_INVALID;
172 * Create a new attribute, broken out of
173 * the stupid sub-attribute crap.
175 * Didn't they know that VSA's exist?
177 sub = paircreate(PW_DIGEST_REALM - 1 + p[0],
180 return RLM_MODULE_FAIL; /* out of memory */
182 memcpy(&sub->vp_octets[0], &p[2], attrlen - 2);
183 sub->vp_octets[attrlen - 2] = '\0';
184 sub->length = attrlen - 2;
188 vp_print(stdout, sub);
193 * And add it to the request pairs.
195 pairadd(&request->packet->vps, sub);
198 * FIXME: Check for the existence
199 * of the necessary attributes!
204 } /* loop over this one attribute */
207 * Find the next one, if it exists.
209 vp = pairfind(vp->next, PW_DIGEST_ATTRIBUTES);
213 * We require access to the Digest-Nonce-Value
215 nonce = pairfind(request->packet->vps, PW_DIGEST_NONCE);
217 DEBUG("ERROR: No Digest-Nonce: Cannot perform Digest authentication");
218 return RLM_MODULE_INVALID;
222 * A1 = Digest-User-Name ":" Realm ":" Password
224 vp = pairfind(request->packet->vps, PW_DIGEST_USER_NAME);
226 DEBUG("ERROR: No Digest-User-Name: Cannot perform Digest authentication");
227 return RLM_MODULE_INVALID;
229 memcpy(&a1[0], &vp->vp_octets[0], vp->length);
235 vp = pairfind(request->packet->vps, PW_DIGEST_REALM);
237 DEBUG("ERROR: No Digest-Realm: Cannot perform Digest authentication");
238 return RLM_MODULE_INVALID;
240 memcpy(&a1[a1_len], &vp->vp_octets[0], vp->length);
241 a1_len += vp->length;
246 vp = pairfind(request->config_items, PW_PASSWORD);
248 DEBUG("ERROR: No User-Password: Cannot perform Digest authentication");
249 return RLM_MODULE_INVALID;
251 memcpy(&a1[a1_len], &vp->vp_octets[0], vp->length);
252 a1_len += vp->length;
255 DEBUG2("A1 = %s", a1);
258 * See which variant we calculate.
260 vp = pairfind(request->packet->vps, PW_DIGEST_ALGORITHM);
262 (strcasecmp(vp->vp_strvalue, "MD5-sess") == 0)) {
263 librad_md5_calc(hash, &a1[0], a1_len);
264 memcpy(&a1[0], hash, 16);
271 * Tack on the Digest-Nonce
273 hex2bin(&a1[a1_len], &nonce->vp_octets[0]);
274 a1_len += (nonce->length >> 1); /* FIXME: CHECK LENGTH */
279 vp = pairfind(request->packet->vps, PW_DIGEST_CNONCE);
281 DEBUG("ERROR: No Digest-CNonce: Cannot perform Digest authentication");
282 return RLM_MODULE_INVALID;
285 hex2bin(&a1[a1_len], &vp->vp_octets[0]);
286 a1_len += (vp->length >> 1); /* FIXME: CHECK LENGTH */
288 } else if ((vp != NULL) &&
289 (strcasecmp(vp->vp_strvalue, "MD5") != 0)) {
291 * We check for "MD5-sess" and "MD5".
292 * Anything else is an error.
294 DEBUG("ERROR: Unknown Digest-Algorithm \"%s\": Cannot perform Digest authentication", vp->vp_strvalue);
295 return RLM_MODULE_INVALID;
299 * A2 = Digest-Method ":" Digest-URI
301 vp = pairfind(request->packet->vps, PW_DIGEST_METHOD);
303 DEBUG("ERROR: No Digest-Method: Cannot perform Digest authentication");
304 return RLM_MODULE_INVALID;
306 memcpy(&a2[0], &vp->vp_octets[0], vp->length);
312 vp = pairfind(request->packet->vps, PW_DIGEST_URI);
314 DEBUG("ERROR: No Digest-URI: Cannot perform Digest authentication");
315 return RLM_MODULE_INVALID;
317 memcpy(&a2[a2_len], &vp->vp_octets[0], vp->length);
318 a2_len += vp->length;
321 * QOP is "auth-int", tack on ": Digest-Body-Digest"
323 qop = pairfind(request->packet->vps, PW_DIGEST_QOP);
325 (strcasecmp(qop->vp_strvalue, "auth-int") == 0)) {
329 * Add in Digest-Body-Digest
335 * Must be a hex representation of an MD5 digest.
337 body = pairfind(request->packet->vps, PW_DIGEST_BODY_DIGEST);
339 DEBUG("ERROR: No Digest-Body-Digest: Cannot perform Digest authentication");
340 return RLM_MODULE_INVALID;
343 rad_assert(body->length == 32); /* FIXME: check in 'auth' */
344 hex2bin(&a2[a2_len], &body->vp_octets[0]);
345 a2_len += (body->length >> 1);
347 } else if ((qop != NULL) &&
348 (strcasecmp(qop->vp_strvalue, "auth") != 0)) {
349 DEBUG("ERROR: Unknown Digest-QOP \"%s\": Cannot perform Digest authentication", qop->vp_strvalue);
350 return RLM_MODULE_INVALID;
354 DEBUG2("A2 = %s", a2);
357 * KD = H(A1) : Digest-Nonce ... : H(A2)
359 librad_md5_calc(&hash[0], &a1[0], a1_len);
361 for (i = 0; i < 16; i++) {
362 sprintf(&kd[i * 2], "%02x", hash[i]);
368 for (i = 0; i < 16; i++) {
369 printf("%02x", hash[i]);
379 memcpy(&kd[kd_len], nonce->vp_octets, nonce->length);
380 kd_len += nonce->length;
383 * No QOP defined. Do RFC 2069 compatibility.
390 } else { /* Digest-QOP MUST be "auth" or "auth-int" */
392 * Tack on ":" Digest-Nonce-Count ":" Digest-CNonce
398 vp = pairfind(request->packet->vps, PW_DIGEST_NONCE_COUNT);
400 DEBUG("ERROR: No Digest-Nonce-Count: Cannot perform Digest authentication");
401 return RLM_MODULE_INVALID;
403 memcpy(&kd[kd_len], &vp->vp_octets[0], vp->length);
404 kd_len += vp->length;
409 vp = pairfind(request->packet->vps, PW_DIGEST_CNONCE);
411 DEBUG("ERROR: No Digest-CNonce: Cannot perform Digest authentication");
412 return RLM_MODULE_INVALID;
414 memcpy(&kd[kd_len], &vp->vp_octets[0], vp->length);
415 kd_len += vp->length;
420 memcpy(&kd[kd_len], &qop->vp_octets[0], qop->length);
421 kd_len += qop->length;
430 librad_md5_calc(&hash[0], &a2[0], a2_len);
432 for (i = 0; i < 16; i++) {
433 sprintf(&kd[kd_len + (i * 2)], "%02x", hash[i]);
439 for (i = 0; i < 16; i++) {
440 printf("%02x", hash[i]);
449 DEBUG2("KD = %s\n", &kd[0]);
452 * Take the hash of KD.
454 librad_md5_calc(&hash[0], &kd[0], kd_len);
455 memcpy(&kd[0], &hash[0], 16);
458 * Get the binary value of Digest-Response
460 vp = pairfind(request->packet->vps, PW_DIGEST_RESPONSE);
461 rad_assert(vp != NULL);
463 hex2bin(&hash[0], &vp->vp_octets[0]);
468 for (i = 0; i < 16; i++) {
469 printf("%02x", kd[i]);
474 for (i = 0; i < 16; i++) {
475 printf("%02x", hash[i]);
482 * And finally, compare the digest in the packet with KD.
484 if (memcmp(&kd[0], &hash[0], 16) == 0) {
485 return RLM_MODULE_OK;
488 DEBUG("rlm_digest: FAILED authentication");
489 return RLM_MODULE_REJECT;
493 * The module name should be the only globally exported symbol.
494 * That is, everything else should be 'static'.
496 * If the module needs to temporarily modify it's instantiation
497 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
498 * The server will then take care of ensuring that the module
499 * is single-threaded.
501 module_t rlm_digest = {
505 NULL, /* instantiation */
508 digest_authenticate, /* authentication */
509 digest_authorize, /* authorization */
510 NULL, /* preaccounting */
511 NULL, /* accounting */
512 NULL, /* checksimul */
513 NULL, /* pre-proxy */
514 NULL, /* post-proxy */