2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 /* The rxkad security object. Authentication using a DES-encrypted
11 * Kerberos-style ticket. These are the server-only routines. */
14 #include <afsconfig.h>
15 #include <afs/param.h>
21 #include <sys/types.h>
22 #if (defined(AFS_AIX_ENV) && defined(KERNEL) && !defined(UKERNEL)) || defined(AFS_AUX_ENV) || defined(AFS_SUN5_ENV)
23 #include <sys/systm.h>
29 #include <netinet/in.h>
35 #include <afs/afsutil.h>
36 #include <des/stats.h>
37 #include "private_data.h"
38 #define XPRT_RXKAD_SERVER
41 * This can be set to allow alternate ticket decoding.
42 * Currently only used by the AFS/DFS protocol translator to recognize
43 * Kerberos V5 tickets. The actual code to do that is provided externally.
45 afs_int32(*rxkad_AlternateTicketDecoder) ();
47 static struct rx_securityOps rxkad_server_ops = {
50 rxkad_PreparePacket, /* once per packet creation */
51 0, /* send packet (once per retrans) */
52 rxkad_CheckAuthentication,
53 rxkad_CreateChallenge,
57 rxkad_CheckPacket, /* check data packet */
58 rxkad_DestroyConnection,
64 extern afs_uint32 rx_MyMaxSendSize;
66 /* Miscellaneous random number routines that use the fcrypt module and the
69 static fc_KeySchedule random_int32_schedule;
71 #ifdef AFS_PTHREAD_ENV
73 * This mutex protects the following global variables:
74 * random_int32_schedule
79 pthread_mutex_t rxkad_random_mutex;
80 #define LOCK_RM assert(pthread_mutex_lock(&rxkad_random_mutex)==0)
81 #define UNLOCK_RM assert(pthread_mutex_unlock(&rxkad_random_mutex)==0)
85 #endif /* AFS_PTHREAD_ENV */
88 init_random_int32(void)
92 gettimeofday(&key, NULL);
94 fc_keysched((struct ktc_encryptionKey*)&key, random_int32_schedule);
99 get_random_int32(void)
101 static struct timeval seed;
105 fc_ecb_encrypt(&seed, &seed, random_int32_schedule, ENCRYPT);
111 /* Called with four parameters. The first is the level of encryption, as
112 defined in the rxkad.h file. The second and third are a rock and a
113 procedure that is called with the key version number that accompanies the
114 ticket and returns a pointer to the server's decryption key. The fourth
115 argument, if not NULL, is a pointer to a function that will be called for
116 every new connection with the name, instance and cell of the client. The
117 routine should return zero if the user is NOT acceptible to the server. If
118 this routine is not supplied, the server can call rxkad_GetServerInfo with
119 the rx connection pointer passed to the RPC routine to obtain information
123 rxkad_level level; * minimum level *
124 char *get_key_rock; * rock for get_key implementor *
125 int (*get_key)(); * passed kvno & addr(key) to fill *
126 int (*user_ok)(); * passed name, inst, cell => bool *
129 struct rx_securityClass *
130 rxkad_NewServerSecurityObject(rxkad_level level, char *get_key_rock,
131 int (*get_key) (char *get_key_rock, int kvno,
132 struct ktc_encryptionKey *
134 int (*user_ok) (char *name, char *instance,
135 char *cell, afs_int32 kvno))
137 struct rx_securityClass *tsc;
138 struct rxkad_sprivate *tsp;
144 size = sizeof(struct rx_securityClass);
145 tsc = (struct rx_securityClass *)osi_Alloc(size);
146 memset(tsc, 0, size);
147 tsc->refCount = 1; /* caller has one reference */
148 tsc->ops = &rxkad_server_ops;
149 size = sizeof(struct rxkad_sprivate);
150 tsp = (struct rxkad_sprivate *)osi_Alloc(size);
151 memset(tsp, 0, size);
152 tsc->privateData = (char *)tsp;
154 tsp->type |= rxkad_server; /* so can identify later */
155 tsp->level = level; /* level of encryption */
156 tsp->get_key_rock = get_key_rock;
157 tsp->get_key = get_key; /* to get server ticket */
158 tsp->user_ok = user_ok; /* to inform server of client id. */
161 INC_RXKAD_STATS(serverObjects);
165 /* server: called to tell if a connection authenticated properly */
168 rxkad_CheckAuthentication(struct rx_securityClass *aobj,
169 struct rx_connection *aconn)
171 struct rxkad_sconn *sconn;
173 /* first make sure the object exists */
174 if (!aconn->securityData)
175 return RXKADINCONSISTENCY;
177 sconn = (struct rxkad_sconn *)aconn->securityData;
178 return !sconn->authenticated;
181 /* server: put the current challenge in the connection structure for later use
185 rxkad_CreateChallenge(struct rx_securityClass *aobj,
186 struct rx_connection *aconn)
188 struct rxkad_sconn *sconn;
189 struct rxkad_sprivate *tsp;
191 sconn = (struct rxkad_sconn *)aconn->securityData;
192 sconn->challengeID = get_random_int32();
193 sconn->authenticated = 0; /* conn unauth. 'til we hear back */
194 /* initialize level from object's minimum acceptable level */
195 tsp = (struct rxkad_sprivate *)aobj->privateData;
196 sconn->level = tsp->level;
200 /* server: fill in a challenge in the packet */
203 rxkad_GetChallenge(struct rx_securityClass *aobj, struct rx_connection *aconn,
204 struct rx_packet *apacket)
206 struct rxkad_sconn *sconn;
209 struct rxkad_v2Challenge c_v2; /* version 2 */
210 struct rxkad_oldChallenge c_old; /* old style */
212 sconn = (struct rxkad_sconn *)aconn->securityData;
213 if (rx_IsUsingPktCksum(aconn))
214 sconn->cksumSeen = 1;
216 if (sconn->cksumSeen) {
217 memset(&c_v2, 0, sizeof(c_v2));
218 c_v2.version = htonl(RXKAD_CHALLENGE_PROTOCOL_VERSION);
219 c_v2.challengeID = htonl(sconn->challengeID);
220 c_v2.level = htonl((afs_int32) sconn->level);
222 challenge = (char *)&c_v2;
223 challengeSize = sizeof(c_v2);
225 memset(&c_old, 0, sizeof(c_old));
226 c_old.challengeID = htonl(sconn->challengeID);
227 c_old.level = htonl((afs_int32) sconn->level);
228 challenge = (char *)&c_old;
229 challengeSize = sizeof(c_old);
231 if (rx_MyMaxSendSize < challengeSize)
232 return RXKADPACKETSHORT; /* not enough space */
234 rx_packetwrite(apacket, 0, challengeSize, challenge);
235 rx_SetDataSize(apacket, challengeSize);
237 INC_RXKAD_STATS(challengesSent);
241 /* server: process a response to a challenge packet */
242 /* XXX this does some copying of data in and out of the packet, but I'll bet it
243 * could just do it in place, especially if I used rx_Pullup...
246 rxkad_CheckResponse(struct rx_securityClass *aobj,
247 struct rx_connection *aconn, struct rx_packet *apacket)
249 struct rxkad_sconn *sconn;
250 struct rxkad_sprivate *tsp;
251 struct ktc_encryptionKey serverKey;
252 struct rxkad_oldChallengeResponse oldr; /* response format */
253 struct rxkad_v2ChallengeResponse v2r;
254 afs_int32 tlen; /* ticket len */
255 afs_int32 kvno; /* key version of ticket */
256 char tix[MAXKTCTICKETLEN];
257 afs_int32 incChallengeID;
260 /* ticket contents */
261 struct ktc_principal client;
262 struct ktc_encryptionKey sessionkey;
267 struct rxkad_serverinfo *rock;
269 sconn = (struct rxkad_sconn *)aconn->securityData;
270 tsp = (struct rxkad_sprivate *)aobj->privateData;
272 if (sconn->cksumSeen) {
273 /* expect v2 response, leave fields in v2r in network order for cksum
274 * computation which follows decryption. */
275 if (rx_GetDataSize(apacket) < sizeof(v2r))
276 return RXKADPACKETSHORT;
277 rx_packetread(apacket, 0, sizeof(v2r), &v2r);
281 kvno = ntohl(v2r.kvno);
282 tlen = ntohl(v2r.ticketLen);
283 if (rx_GetDataSize(apacket) < sizeof(v2r) + tlen)
284 return RXKADPACKETSHORT;
286 /* expect old format response */
287 if (rx_GetDataSize(apacket) < sizeof(oldr))
288 return RXKADPACKETSHORT;
289 rx_packetread(apacket, 0, sizeof(oldr), &oldr);
292 kvno = ntohl(oldr.kvno);
293 tlen = ntohl(oldr.ticketLen);
294 if (rx_GetDataSize(apacket) != sizeof(oldr) + tlen)
295 return RXKADPACKETSHORT;
297 if ((tlen < MINKTCTICKETLEN) || (tlen > MAXKTCTICKETLEN))
298 return RXKADTICKETLEN;
300 rx_packetread(apacket, pos, tlen, tix); /* get ticket */
303 * We allow the ticket to be optionally decoded by an alternate
304 * ticket decoder, if the function variable
305 * rxkad_AlternateTicketDecoder is set. That function should
306 * return a code of -1 if it wants the ticket to be decoded by
307 * the standard decoder.
309 if (rxkad_AlternateTicketDecoder) {
311 rxkad_AlternateTicketDecoder(kvno, tix, tlen, client.name,
312 client.instance, client.cell,
313 &sessionkey, &host, &start, &end);
314 if (code && code != -1) {
318 code = -1; /* No alternate ticket decoder present */
322 * If the alternate decoder is not present, or returns -1, then
323 * assume the ticket is of the default style.
325 if (code == -1 && ((kvno == RXKAD_TKT_TYPE_KERBEROS_V5)
326 || (kvno == RXKAD_TKT_TYPE_KERBEROS_V5_ENCPART_ONLY))) {
328 tkt_DecodeTicket5(tix, tlen, tsp->get_key, tsp->get_key_rock,
329 kvno, client.name, client.instance, client.cell,
330 &sessionkey, &host, &start, &end);
336 * If the alternate decoder/kerberos 5 decoder is not present, or
337 * returns -1, then assume the ticket is of the default style.
340 /* get ticket's key */
341 code = (*tsp->get_key) (tsp->get_key_rock, kvno, &serverKey);
343 return RXKADUNKNOWNKEY; /* invalid kvno */
345 tkt_DecodeTicket(tix, tlen, &serverKey, client.name,
346 client.instance, client.cell, &sessionkey, &host,
351 code = tkt_CheckTimes(start, end, time(0));
357 return RXKADBADTICKET;
359 code = fc_keysched(&sessionkey, sconn->keysched);
362 memcpy(sconn->ivec, &sessionkey, sizeof(sconn->ivec));
364 if (sconn->cksumSeen) {
365 /* using v2 response */
366 afs_uint32 cksum; /* observed cksum */
367 struct rxkad_endpoint endpoint; /* connections endpoint */
371 memcpy(xor, sconn->ivec, 2 * sizeof(afs_int32));
372 fc_cbc_encrypt(&v2r.encrypted, &v2r.encrypted, sizeof(v2r.encrypted),
373 sconn->keysched, xor, DECRYPT);
374 cksum = rxkad_CksumChallengeResponse(&v2r);
375 if (cksum != v2r.encrypted.endpoint.cksum)
376 return RXKADSEALEDINCON;
377 (void)rxkad_SetupEndpoint(aconn, &endpoint);
378 v2r.encrypted.endpoint.cksum = 0;
379 if (memcmp(&endpoint, &v2r.encrypted.endpoint, sizeof(endpoint)) != 0)
380 return RXKADSEALEDINCON;
381 for (i = 0; i < RX_MAXCALLS; i++) {
382 v2r.encrypted.callNumbers[i] =
383 ntohl(v2r.encrypted.callNumbers[i]);
384 if (v2r.encrypted.callNumbers[i] < 0)
385 return RXKADSEALEDINCON;
388 (void)rxi_SetCallNumberVector(aconn, v2r.encrypted.callNumbers);
389 incChallengeID = ntohl(v2r.encrypted.incChallengeID);
390 level = ntohl(v2r.encrypted.level);
392 /* expect old format response */
393 fc_ecb_encrypt(&oldr.encrypted, &oldr.encrypted, sconn->keysched,
395 incChallengeID = ntohl(oldr.encrypted.incChallengeID);
396 level = ntohl(oldr.encrypted.level);
398 if (incChallengeID != sconn->challengeID + 1)
399 return RXKADOUTOFSEQUENCE; /* replay attempt */
400 if ((level < sconn->level) || (level > rxkad_crypt))
401 return RXKADLEVELFAIL;
402 sconn->level = level;
403 rxkad_SetLevel(aconn, sconn->level);
404 INC_RXKAD_STATS(responses[rxkad_LevelIndex(sconn->level)]);
405 /* now compute endpoint-specific info used for computing 16 bit checksum */
406 rxkad_DeriveXORInfo(aconn, sconn->keysched, sconn->ivec, sconn->preSeq);
408 /* otherwise things are ok */
409 sconn->expirationTime = end;
410 sconn->authenticated = 1;
413 code = tsp->user_ok(client.name, client.instance, client.cell, kvno);
416 } else { /* save the info for later retreival */
417 int size = sizeof(struct rxkad_serverinfo);
418 rock = (struct rxkad_serverinfo *)osi_Alloc(size);
419 memset(rock, 0, size);
421 memcpy(&rock->client, &client, sizeof(rock->client));
427 /* return useful authentication info about a server-side connection */
430 rxkad_GetServerInfo(struct rx_connection * aconn, rxkad_level * level,
431 afs_uint32 * expiration, char *name, char *instance,
432 char *cell, afs_int32 * kvno)
434 struct rxkad_sconn *sconn;
436 sconn = (struct rxkad_sconn *)aconn->securityData;
437 if (sconn && sconn->authenticated && sconn->rock
438 && (time(0) < sconn->expirationTime)) {
440 *level = sconn->level;
442 *expiration = sconn->expirationTime;
444 strcpy(name, sconn->rock->client.name);
446 strcpy(instance, sconn->rock->client.instance);
448 strcpy(cell, sconn->rock->client.cell);
450 *kvno = sconn->rock->kvno;