1 /* Kerberos-based RxRPC security
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/udp.h>
16 #include <linux/crypto.h>
17 #include <linux/scatterlist.h>
18 #include <linux/ctype.h>
19 #include <linux/slab.h>
21 #include <net/af_rxrpc.h>
22 #include <keys/rxrpc-type.h>
23 #define rxrpc_debug rxkad_debug
24 #include "ar-internal.h"
26 #define RXKAD_VERSION 2
27 #define MAXKRB5TICKETLEN 1024
28 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
29 #define ANAME_SZ 40 /* size of authentication name */
30 #define INST_SZ 40 /* size of principal's instance */
31 #define REALM_SZ 40 /* size of principal's auth domain */
32 #define SNAME_SZ 40 /* size of service name */
34 unsigned int rxrpc_debug;
35 module_param_named(debug, rxrpc_debug, uint, S_IWUSR | S_IRUGO);
36 MODULE_PARM_DESC(debug, "rxkad debugging mask");
38 struct rxkad_level1_hdr {
39 __be32 data_size; /* true data size (excluding padding) */
42 struct rxkad_level2_hdr {
43 __be32 data_size; /* true data size (excluding padding) */
44 __be32 checksum; /* decrypted data checksum */
47 MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)");
48 MODULE_AUTHOR("Red Hat, Inc.");
49 MODULE_LICENSE("GPL");
52 * this holds a pinned cipher so that keventd doesn't get called by the cipher
53 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
56 static struct crypto_blkcipher *rxkad_ci;
57 static DEFINE_MUTEX(rxkad_ci_mutex);
60 * initialise connection security
62 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
64 struct crypto_blkcipher *ci;
65 struct rxrpc_key_token *token;
68 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->key));
70 token = conn->key->payload.data[0];
71 conn->security_ix = token->security_index;
73 ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
80 if (crypto_blkcipher_setkey(ci, token->kad->session_key,
81 sizeof(token->kad->session_key)) < 0)
84 switch (conn->security_level) {
85 case RXRPC_SECURITY_PLAIN:
87 case RXRPC_SECURITY_AUTH:
89 conn->security_size = sizeof(struct rxkad_level1_hdr);
90 conn->header_size += sizeof(struct rxkad_level1_hdr);
92 case RXRPC_SECURITY_ENCRYPT:
94 conn->security_size = sizeof(struct rxkad_level2_hdr);
95 conn->header_size += sizeof(struct rxkad_level2_hdr);
105 _leave(" = %d", ret);
110 * prime the encryption state with the invariant parts of a connection's
113 static void rxkad_prime_packet_security(struct rxrpc_connection *conn)
115 struct rxrpc_key_token *token;
116 struct blkcipher_desc desc;
117 struct scatterlist sg[2];
118 struct rxrpc_crypt iv;
121 } tmpbuf __attribute__((aligned(16))); /* must all be in same page */
128 token = conn->key->payload.data[0];
129 memcpy(&iv, token->kad->session_key, sizeof(iv));
131 desc.tfm = conn->cipher;
135 tmpbuf.x[0] = conn->epoch;
136 tmpbuf.x[1] = conn->cid;
138 tmpbuf.x[3] = htonl(conn->security_ix);
140 sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
141 sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
142 crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
144 memcpy(&conn->csum_iv, &tmpbuf.x[2], sizeof(conn->csum_iv));
145 ASSERTCMP(conn->csum_iv.n[0], ==, tmpbuf.x[2]);
151 * partially encrypt a packet (level 1 security)
153 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
158 struct rxrpc_skb_priv *sp;
159 struct blkcipher_desc desc;
160 struct rxrpc_crypt iv;
161 struct scatterlist sg[2];
163 struct rxkad_level1_hdr hdr;
164 __be32 first; /* first four bytes of data and padding */
165 } tmpbuf __attribute__((aligned(8))); /* must all be in same page */
172 check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
173 data_size |= (u32) check << 16;
175 tmpbuf.hdr.data_size = htonl(data_size);
176 memcpy(&tmpbuf.first, sechdr + 4, sizeof(tmpbuf.first));
178 /* start the encryption afresh */
179 memset(&iv, 0, sizeof(iv));
180 desc.tfm = call->conn->cipher;
184 sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
185 sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
186 crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
188 memcpy(sechdr, &tmpbuf, sizeof(tmpbuf));
195 * wholly encrypt a packet (level 2 security)
197 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
202 const struct rxrpc_key_token *token;
203 struct rxkad_level2_hdr rxkhdr
204 __attribute__((aligned(8))); /* must be all on one page */
205 struct rxrpc_skb_priv *sp;
206 struct blkcipher_desc desc;
207 struct rxrpc_crypt iv;
208 struct scatterlist sg[16];
209 struct sk_buff *trailer;
218 check = ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
220 rxkhdr.data_size = htonl(data_size | (u32) check << 16);
223 /* encrypt from the session key */
224 token = call->conn->key->payload.data[0];
225 memcpy(&iv, token->kad->session_key, sizeof(iv));
226 desc.tfm = call->conn->cipher;
230 sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
231 sg_init_one(&sg[1], &rxkhdr, sizeof(rxkhdr));
232 crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(rxkhdr));
234 /* we want to encrypt the skbuff in-place */
235 nsg = skb_cow_data(skb, 0, &trailer);
236 if (nsg < 0 || nsg > 16)
239 len = data_size + call->conn->size_align - 1;
240 len &= ~(call->conn->size_align - 1);
242 sg_init_table(sg, nsg);
243 err = skb_to_sgvec(skb, sg, 0, len);
244 if (unlikely(err < 0))
246 crypto_blkcipher_encrypt_iv(&desc, sg, sg, len);
253 * checksum an RxRPC packet header
255 static int rxkad_secure_packet(const struct rxrpc_call *call,
260 struct rxrpc_skb_priv *sp;
261 struct blkcipher_desc desc;
262 struct rxrpc_crypt iv;
263 struct scatterlist sg[2];
266 } tmpbuf __attribute__((aligned(8))); /* must all be in same page */
273 _enter("{%d{%x}},{#%u},%zu,",
274 call->debug_id, key_serial(call->conn->key), ntohl(sp->hdr.seq),
277 if (!call->conn->cipher)
280 ret = key_validate(call->conn->key);
284 /* continue encrypting from where we left off */
285 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
286 desc.tfm = call->conn->cipher;
290 /* calculate the security checksum */
291 x = htonl(call->channel << (32 - RXRPC_CIDSHIFT));
292 x |= sp->hdr.seq & cpu_to_be32(0x3fffffff);
293 tmpbuf.x[0] = sp->hdr.callNumber;
296 sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
297 sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
298 crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
300 y = ntohl(tmpbuf.x[1]);
301 y = (y >> 16) & 0xffff;
303 y = 1; /* zero checksums are not permitted */
304 sp->hdr.cksum = htons(y);
306 switch (call->conn->security_level) {
307 case RXRPC_SECURITY_PLAIN:
310 case RXRPC_SECURITY_AUTH:
311 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr);
313 case RXRPC_SECURITY_ENCRYPT:
314 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
322 _leave(" = %d [set %hx]", ret, y);
327 * decrypt partial encryption on a packet (level 1 security)
329 static int rxkad_verify_packet_auth(const struct rxrpc_call *call,
333 struct rxkad_level1_hdr sechdr;
334 struct rxrpc_skb_priv *sp;
335 struct blkcipher_desc desc;
336 struct rxrpc_crypt iv;
337 struct scatterlist sg[16];
338 struct sk_buff *trailer;
347 /* we want to decrypt the skbuff in-place */
348 nsg = skb_cow_data(skb, 0, &trailer);
349 if (nsg < 0 || nsg > 16)
352 sg_init_table(sg, nsg);
353 ret = skb_to_sgvec(skb, sg, 0, 8);
354 if (unlikely(ret < 0))
357 /* start the decryption afresh */
358 memset(&iv, 0, sizeof(iv));
359 desc.tfm = call->conn->cipher;
363 crypto_blkcipher_decrypt_iv(&desc, sg, sg, 8);
365 /* remove the decrypted packet length */
366 if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0)
368 if (!skb_pull(skb, sizeof(sechdr)))
371 buf = ntohl(sechdr.data_size);
372 data_size = buf & 0xffff;
375 check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
378 *_abort_code = RXKADSEALEDINCON;
382 /* shorten the packet to remove the padding */
383 if (data_size > skb->len)
385 else if (data_size < skb->len)
386 skb->len = data_size;
388 _leave(" = 0 [dlen=%x]", data_size);
392 *_abort_code = RXKADDATALEN;
394 _leave(" = -EPROTO");
398 _leave(" = -ENOMEM");
403 * wholly decrypt a packet (level 2 security)
405 static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call,
409 const struct rxrpc_key_token *token;
410 struct rxkad_level2_hdr sechdr;
411 struct rxrpc_skb_priv *sp;
412 struct blkcipher_desc desc;
413 struct rxrpc_crypt iv;
414 struct scatterlist _sg[4], *sg;
415 struct sk_buff *trailer;
420 _enter(",{%d}", skb->len);
424 /* we want to decrypt the skbuff in-place */
425 nsg = skb_cow_data(skb, 0, &trailer);
430 if (unlikely(nsg > 4)) {
431 sg = kmalloc(sizeof(*sg) * nsg, GFP_NOIO);
436 sg_init_table(sg, nsg);
437 ret = skb_to_sgvec(skb, sg, 0, skb->len);
438 if (unlikely(ret < 0)) {
444 /* decrypt from the session key */
445 token = call->conn->key->payload.data[0];
446 memcpy(&iv, token->kad->session_key, sizeof(iv));
447 desc.tfm = call->conn->cipher;
451 crypto_blkcipher_decrypt_iv(&desc, sg, sg, skb->len);
455 /* remove the decrypted packet length */
456 if (skb_copy_bits(skb, 0, &sechdr, sizeof(sechdr)) < 0)
458 if (!skb_pull(skb, sizeof(sechdr)))
461 buf = ntohl(sechdr.data_size);
462 data_size = buf & 0xffff;
465 check ^= ntohl(sp->hdr.seq ^ sp->hdr.callNumber);
468 *_abort_code = RXKADSEALEDINCON;
472 /* shorten the packet to remove the padding */
473 if (data_size > skb->len)
475 else if (data_size < skb->len)
476 skb->len = data_size;
478 _leave(" = 0 [dlen=%x]", data_size);
482 *_abort_code = RXKADDATALEN;
484 _leave(" = -EPROTO");
488 _leave(" = -ENOMEM");
493 * verify the security on a received packet
495 static int rxkad_verify_packet(const struct rxrpc_call *call,
499 struct blkcipher_desc desc;
500 struct rxrpc_skb_priv *sp;
501 struct rxrpc_crypt iv;
502 struct scatterlist sg[2];
505 } tmpbuf __attribute__((aligned(8))); /* must all be in same page */
513 _enter("{%d{%x}},{#%u}",
514 call->debug_id, key_serial(call->conn->key),
517 if (!call->conn->cipher)
520 if (sp->hdr.securityIndex != RXRPC_SECURITY_RXKAD) {
521 *_abort_code = RXKADINCONSISTENCY;
522 _leave(" = -EPROTO [not rxkad]");
526 /* continue encrypting from where we left off */
527 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
528 desc.tfm = call->conn->cipher;
532 /* validate the security checksum */
533 x = htonl(call->channel << (32 - RXRPC_CIDSHIFT));
534 x |= sp->hdr.seq & cpu_to_be32(0x3fffffff);
535 tmpbuf.x[0] = call->call_id;
538 sg_init_one(&sg[0], &tmpbuf, sizeof(tmpbuf));
539 sg_init_one(&sg[1], &tmpbuf, sizeof(tmpbuf));
540 crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
542 y = ntohl(tmpbuf.x[1]);
543 y = (y >> 16) & 0xffff;
545 y = 1; /* zero checksums are not permitted */
548 if (sp->hdr.cksum != cksum) {
549 *_abort_code = RXKADSEALEDINCON;
550 _leave(" = -EPROTO [csum failed]");
554 switch (call->conn->security_level) {
555 case RXRPC_SECURITY_PLAIN:
558 case RXRPC_SECURITY_AUTH:
559 ret = rxkad_verify_packet_auth(call, skb, _abort_code);
561 case RXRPC_SECURITY_ENCRYPT:
562 ret = rxkad_verify_packet_encrypt(call, skb, _abort_code);
569 _leave(" = %d", ret);
576 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
578 struct rxkad_challenge challenge;
579 struct rxrpc_header hdr;
585 _enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
587 ret = key_validate(conn->key);
591 get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
593 challenge.version = htonl(2);
594 challenge.nonce = htonl(conn->security_nonce);
595 challenge.min_level = htonl(0);
596 challenge.__padding = 0;
598 msg.msg_name = &conn->trans->peer->srx.transport.sin;
599 msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin);
600 msg.msg_control = NULL;
601 msg.msg_controllen = 0;
604 hdr.epoch = conn->epoch;
608 hdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
609 hdr.flags = conn->out_clientflag;
611 hdr.securityIndex = conn->security_ix;
613 hdr.serviceId = conn->service_id;
615 iov[0].iov_base = &hdr;
616 iov[0].iov_len = sizeof(hdr);
617 iov[1].iov_base = &challenge;
618 iov[1].iov_len = sizeof(challenge);
620 len = iov[0].iov_len + iov[1].iov_len;
622 hdr.serial = htonl(atomic_inc_return(&conn->serial));
623 _proto("Tx CHALLENGE %%%u", ntohl(hdr.serial));
625 ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 2, len);
627 _debug("sendmsg failed: %d", ret);
636 * send a Kerberos security response
638 static int rxkad_send_response(struct rxrpc_connection *conn,
639 struct rxrpc_header *hdr,
640 struct rxkad_response *resp,
641 const struct rxkad_key *s2)
650 msg.msg_name = &conn->trans->peer->srx.transport.sin;
651 msg.msg_namelen = sizeof(conn->trans->peer->srx.transport.sin);
652 msg.msg_control = NULL;
653 msg.msg_controllen = 0;
656 hdr->epoch = conn->epoch;
658 hdr->type = RXRPC_PACKET_TYPE_RESPONSE;
659 hdr->flags = conn->out_clientflag;
663 iov[0].iov_base = hdr;
664 iov[0].iov_len = sizeof(*hdr);
665 iov[1].iov_base = resp;
666 iov[1].iov_len = sizeof(*resp);
667 iov[2].iov_base = (void *) s2->ticket;
668 iov[2].iov_len = s2->ticket_len;
670 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
672 hdr->serial = htonl(atomic_inc_return(&conn->serial));
673 _proto("Tx RESPONSE %%%u", ntohl(hdr->serial));
675 ret = kernel_sendmsg(conn->trans->local->socket, &msg, iov, 3, len);
677 _debug("sendmsg failed: %d", ret);
686 * calculate the response checksum
688 static void rxkad_calc_response_checksum(struct rxkad_response *response)
692 u8 *p = (u8 *) response;
694 for (loop = sizeof(*response); loop > 0; loop--)
695 csum = csum * 0x10204081 + *p++;
697 response->encrypted.checksum = htonl(csum);
701 * load a scatterlist with a potentially split-page buffer
703 static void rxkad_sg_set_buf2(struct scatterlist sg[2],
704 void *buf, size_t buflen)
708 sg_init_table(sg, 2);
710 sg_set_buf(&sg[0], buf, buflen);
711 if (sg[0].offset + buflen > PAGE_SIZE) {
712 /* the buffer was split over two pages */
713 sg[0].length = PAGE_SIZE - sg[0].offset;
714 sg_set_buf(&sg[1], buf + sg[0].length, buflen - sg[0].length);
718 sg_mark_end(&sg[nsg - 1]);
720 ASSERTCMP(sg[0].length + sg[1].length, ==, buflen);
724 * encrypt the response packet
726 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
727 struct rxkad_response *resp,
728 const struct rxkad_key *s2)
730 struct blkcipher_desc desc;
731 struct rxrpc_crypt iv;
732 struct scatterlist sg[2];
734 /* continue encrypting from where we left off */
735 memcpy(&iv, s2->session_key, sizeof(iv));
736 desc.tfm = conn->cipher;
740 rxkad_sg_set_buf2(sg, &resp->encrypted, sizeof(resp->encrypted));
741 crypto_blkcipher_encrypt_iv(&desc, sg, sg, sizeof(resp->encrypted));
745 * respond to a challenge packet
747 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
751 const struct rxrpc_key_token *token;
752 struct rxkad_challenge challenge;
753 struct rxkad_response resp
754 __attribute__((aligned(8))); /* must be aligned for crypto */
755 struct rxrpc_skb_priv *sp;
756 u32 version, nonce, min_level, abort_code;
759 _enter("{%d,%x}", conn->debug_id, key_serial(conn->key));
762 _leave(" = -EPROTO [no key]");
766 ret = key_validate(conn->key);
768 *_abort_code = RXKADEXPIRED;
772 abort_code = RXKADPACKETSHORT;
774 if (skb_copy_bits(skb, 0, &challenge, sizeof(challenge)) < 0)
777 version = ntohl(challenge.version);
778 nonce = ntohl(challenge.nonce);
779 min_level = ntohl(challenge.min_level);
781 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
782 ntohl(sp->hdr.serial), version, nonce, min_level);
784 abort_code = RXKADINCONSISTENCY;
785 if (version != RXKAD_VERSION)
788 abort_code = RXKADLEVELFAIL;
789 if (conn->security_level < min_level)
792 token = conn->key->payload.data[0];
794 /* build the response packet */
795 memset(&resp, 0, sizeof(resp));
797 resp.version = RXKAD_VERSION;
798 resp.encrypted.epoch = conn->epoch;
799 resp.encrypted.cid = conn->cid;
800 resp.encrypted.securityIndex = htonl(conn->security_ix);
801 resp.encrypted.call_id[0] =
802 (conn->channels[0] ? conn->channels[0]->call_id : 0);
803 resp.encrypted.call_id[1] =
804 (conn->channels[1] ? conn->channels[1]->call_id : 0);
805 resp.encrypted.call_id[2] =
806 (conn->channels[2] ? conn->channels[2]->call_id : 0);
807 resp.encrypted.call_id[3] =
808 (conn->channels[3] ? conn->channels[3]->call_id : 0);
809 resp.encrypted.inc_nonce = htonl(nonce + 1);
810 resp.encrypted.level = htonl(conn->security_level);
811 resp.kvno = htonl(token->kad->kvno);
812 resp.ticket_len = htonl(token->kad->ticket_len);
814 /* calculate the response checksum and then do the encryption */
815 rxkad_calc_response_checksum(&resp);
816 rxkad_encrypt_response(conn, &resp, token->kad);
817 return rxkad_send_response(conn, &sp->hdr, &resp, token->kad);
820 *_abort_code = abort_code;
821 _leave(" = -EPROTO [%d]", abort_code);
826 * decrypt the kerberos IV ticket in the response
828 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
829 void *ticket, size_t ticket_len,
830 struct rxrpc_crypt *_session_key,
834 struct blkcipher_desc desc;
835 struct rxrpc_crypt iv, key;
836 struct scatterlist sg[1];
842 u8 *p, *q, *name, *end;
844 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
848 ret = key_validate(conn->server_key);
852 *_abort_code = RXKADEXPIRED;
855 *_abort_code = RXKADNOAUTH;
860 ASSERT(conn->server_key->payload.data[0] != NULL);
861 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
863 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
865 desc.tfm = conn->server_key->payload.data[0];
869 sg_init_one(&sg[0], ticket, ticket_len);
870 crypto_blkcipher_decrypt_iv(&desc, sg, sg, ticket_len);
873 end = p + ticket_len;
878 q = memchr(p, 0, end - p); \
879 if (!q || q - p > (size)) \
888 /* extract the ticket flags */
889 _debug("KIV FLAGS: %x", *p);
890 little_endian = *p & 1;
893 /* extract the authentication name */
895 _debug("KIV ANAME: %s", name);
897 /* extract the principal's instance */
899 _debug("KIV INST : %s", name);
901 /* extract the principal's authentication domain */
903 _debug("KIV REALM: %s", name);
905 if (end - p < 4 + 8 + 4 + 2)
908 /* get the IPv4 address of the entity that requested the ticket */
909 memcpy(&addr, p, sizeof(addr));
911 _debug("KIV ADDR : %pI4", &addr);
913 /* get the session key from the ticket */
914 memcpy(&key, p, sizeof(key));
916 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
917 memcpy(_session_key, &key, sizeof(key));
919 /* get the ticket's lifetime */
920 life = *p++ * 5 * 60;
921 _debug("KIV LIFE : %u", life);
923 /* get the issue time of the ticket */
926 memcpy(&stamp, p, 4);
927 issue = le32_to_cpu(stamp);
930 memcpy(&stamp, p, 4);
931 issue = be32_to_cpu(stamp);
935 _debug("KIV ISSUE: %lx [%lx]", issue, now);
937 /* check the ticket is in date */
939 *_abort_code = RXKADNOAUTH;
944 if (issue < now - life) {
945 *_abort_code = RXKADEXPIRED;
950 *_expiry = issue + life;
952 /* get the service name */
954 _debug("KIV SNAME: %s", name);
956 /* get the service instance name */
958 _debug("KIV SINST: %s", name);
962 _leave(" = %d", ret);
966 *_abort_code = RXKADBADTICKET;
972 * decrypt the response packet
974 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
975 struct rxkad_response *resp,
976 const struct rxrpc_crypt *session_key)
978 struct blkcipher_desc desc;
979 struct scatterlist sg[2];
980 struct rxrpc_crypt iv;
983 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
985 ASSERT(rxkad_ci != NULL);
987 mutex_lock(&rxkad_ci_mutex);
988 if (crypto_blkcipher_setkey(rxkad_ci, session_key->x,
989 sizeof(*session_key)) < 0)
992 memcpy(&iv, session_key, sizeof(iv));
997 rxkad_sg_set_buf2(sg, &resp->encrypted, sizeof(resp->encrypted));
998 crypto_blkcipher_decrypt_iv(&desc, sg, sg, sizeof(resp->encrypted));
999 mutex_unlock(&rxkad_ci_mutex);
1007 static int rxkad_verify_response(struct rxrpc_connection *conn,
1008 struct sk_buff *skb,
1011 struct rxkad_response response
1012 __attribute__((aligned(8))); /* must be aligned for crypto */
1013 struct rxrpc_skb_priv *sp;
1014 struct rxrpc_crypt session_key;
1017 u32 abort_code, version, kvno, ticket_len, level;
1021 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1023 abort_code = RXKADPACKETSHORT;
1024 if (skb_copy_bits(skb, 0, &response, sizeof(response)) < 0)
1025 goto protocol_error;
1026 if (!pskb_pull(skb, sizeof(response)))
1029 version = ntohl(response.version);
1030 ticket_len = ntohl(response.ticket_len);
1031 kvno = ntohl(response.kvno);
1032 sp = rxrpc_skb(skb);
1033 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1034 ntohl(sp->hdr.serial), version, kvno, ticket_len);
1036 abort_code = RXKADINCONSISTENCY;
1037 if (version != RXKAD_VERSION)
1038 goto protocol_error;
1040 abort_code = RXKADTICKETLEN;
1041 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1042 goto protocol_error;
1044 abort_code = RXKADUNKNOWNKEY;
1045 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1046 goto protocol_error;
1048 /* extract the kerberos ticket and decrypt and decode it */
1049 ticket = kmalloc(ticket_len, GFP_NOFS);
1053 abort_code = RXKADPACKETSHORT;
1054 if (skb_copy_bits(skb, 0, ticket, ticket_len) < 0)
1055 goto protocol_error_free;
1057 ret = rxkad_decrypt_ticket(conn, ticket, ticket_len, &session_key,
1058 &expiry, &abort_code);
1060 *_abort_code = abort_code;
1065 /* use the session key from inside the ticket to decrypt the
1067 rxkad_decrypt_response(conn, &response, &session_key);
1069 abort_code = RXKADSEALEDINCON;
1070 if (response.encrypted.epoch != conn->epoch)
1071 goto protocol_error_free;
1072 if (response.encrypted.cid != conn->cid)
1073 goto protocol_error_free;
1074 if (ntohl(response.encrypted.securityIndex) != conn->security_ix)
1075 goto protocol_error_free;
1076 csum = response.encrypted.checksum;
1077 response.encrypted.checksum = 0;
1078 rxkad_calc_response_checksum(&response);
1079 if (response.encrypted.checksum != csum)
1080 goto protocol_error_free;
1082 if (ntohl(response.encrypted.call_id[0]) > INT_MAX ||
1083 ntohl(response.encrypted.call_id[1]) > INT_MAX ||
1084 ntohl(response.encrypted.call_id[2]) > INT_MAX ||
1085 ntohl(response.encrypted.call_id[3]) > INT_MAX)
1086 goto protocol_error_free;
1088 abort_code = RXKADOUTOFSEQUENCE;
1089 if (response.encrypted.inc_nonce != htonl(conn->security_nonce + 1))
1090 goto protocol_error_free;
1092 abort_code = RXKADLEVELFAIL;
1093 level = ntohl(response.encrypted.level);
1094 if (level > RXRPC_SECURITY_ENCRYPT)
1095 goto protocol_error_free;
1096 conn->security_level = level;
1098 /* create a key to hold the security data and expiration time - after
1099 * this the connection security can be handled in exactly the same way
1100 * as for a client connection */
1101 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1111 protocol_error_free:
1114 *_abort_code = abort_code;
1115 _leave(" = -EPROTO [%d]", abort_code);
1120 * clear the connection security
1122 static void rxkad_clear(struct rxrpc_connection *conn)
1127 crypto_free_blkcipher(conn->cipher);
1131 * RxRPC Kerberos-based security
1133 static struct rxrpc_security rxkad = {
1134 .owner = THIS_MODULE,
1136 .security_index = RXRPC_SECURITY_RXKAD,
1137 .init_connection_security = rxkad_init_connection_security,
1138 .prime_packet_security = rxkad_prime_packet_security,
1139 .secure_packet = rxkad_secure_packet,
1140 .verify_packet = rxkad_verify_packet,
1141 .issue_challenge = rxkad_issue_challenge,
1142 .respond_to_challenge = rxkad_respond_to_challenge,
1143 .verify_response = rxkad_verify_response,
1144 .clear = rxkad_clear,
1147 static __init int rxkad_init(void)
1151 /* pin the cipher we need so that the crypto layer doesn't invoke
1152 * keventd to go get it */
1153 rxkad_ci = crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
1154 if (IS_ERR(rxkad_ci))
1155 return PTR_ERR(rxkad_ci);
1157 return rxrpc_register_security(&rxkad);
1160 module_init(rxkad_init);
1162 static __exit void rxkad_exit(void)
1166 rxrpc_unregister_security(&rxkad);
1167 crypto_free_blkcipher(rxkad_ci);
1170 module_exit(rxkad_exit);