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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <crypto/skcipher.h>
15 #include <linux/module.h>
16 #include <linux/net.h>
17 #include <linux/skbuff.h>
18 #include <linux/udp.h>
19 #include <linux/scatterlist.h>
20 #include <linux/ctype.h>
21 #include <linux/slab.h>
23 #include <net/af_rxrpc.h>
24 #include <keys/rxrpc-type.h>
25 #include "ar-internal.h"
27 #define RXKAD_VERSION 2
28 #define MAXKRB5TICKETLEN 1024
29 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
30 #define ANAME_SZ 40 /* size of authentication name */
31 #define INST_SZ 40 /* size of principal's instance */
32 #define REALM_SZ 40 /* size of principal's auth domain */
33 #define SNAME_SZ 40 /* size of service name */
35 struct rxkad_level1_hdr {
36 __be32 data_size; /* true data size (excluding padding) */
39 struct rxkad_level2_hdr {
40 __be32 data_size; /* true data size (excluding padding) */
41 __be32 checksum; /* decrypted data checksum */
45 * this holds a pinned cipher so that keventd doesn't get called by the cipher
46 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
49 static struct crypto_skcipher *rxkad_ci;
50 static DEFINE_MUTEX(rxkad_ci_mutex);
53 * initialise connection security
55 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
57 struct crypto_skcipher *ci;
58 struct rxrpc_key_token *token;
61 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
63 token = conn->params.key->payload.data[0];
64 conn->security_ix = token->security_index;
66 ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
73 if (crypto_skcipher_setkey(ci, token->kad->session_key,
74 sizeof(token->kad->session_key)) < 0)
77 switch (conn->params.security_level) {
78 case RXRPC_SECURITY_PLAIN:
80 case RXRPC_SECURITY_AUTH:
82 conn->security_size = sizeof(struct rxkad_level1_hdr);
84 case RXRPC_SECURITY_ENCRYPT:
86 conn->security_size = sizeof(struct rxkad_level2_hdr);
101 * prime the encryption state with the invariant parts of a connection's
104 static int rxkad_prime_packet_security(struct rxrpc_connection *conn)
106 struct rxrpc_key_token *token;
107 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
108 struct scatterlist sg;
109 struct rxrpc_crypt iv;
111 size_t tmpsize = 4 * sizeof(__be32);
115 if (!conn->params.key)
118 tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
122 token = conn->params.key->payload.data[0];
123 memcpy(&iv, token->kad->session_key, sizeof(iv));
125 tmpbuf[0] = htonl(conn->proto.epoch);
126 tmpbuf[1] = htonl(conn->proto.cid);
128 tmpbuf[3] = htonl(conn->security_ix);
130 sg_init_one(&sg, tmpbuf, tmpsize);
131 skcipher_request_set_tfm(req, conn->cipher);
132 skcipher_request_set_callback(req, 0, NULL, NULL);
133 skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
134 crypto_skcipher_encrypt(req);
135 skcipher_request_zero(req);
137 memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv));
144 * partially encrypt a packet (level 1 security)
146 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
151 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
152 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
153 struct rxkad_level1_hdr hdr;
154 struct rxrpc_crypt iv;
155 struct scatterlist sg;
160 check = sp->hdr.seq ^ call->call_id;
161 data_size |= (u32)check << 16;
163 hdr.data_size = htonl(data_size);
164 memcpy(sechdr, &hdr, sizeof(hdr));
166 /* start the encryption afresh */
167 memset(&iv, 0, sizeof(iv));
169 sg_init_one(&sg, sechdr, 8);
170 skcipher_request_set_tfm(req, call->conn->cipher);
171 skcipher_request_set_callback(req, 0, NULL, NULL);
172 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
173 crypto_skcipher_encrypt(req);
174 skcipher_request_zero(req);
181 * wholly encrypt a packet (level 2 security)
183 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
188 const struct rxrpc_key_token *token;
189 struct rxkad_level2_hdr rxkhdr;
190 struct rxrpc_skb_priv *sp;
191 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
192 struct rxrpc_crypt iv;
193 struct scatterlist sg[16];
194 struct sk_buff *trailer;
204 check = sp->hdr.seq ^ call->call_id;
206 rxkhdr.data_size = htonl(data_size | (u32)check << 16);
208 memcpy(sechdr, &rxkhdr, sizeof(rxkhdr));
210 /* encrypt from the session key */
211 token = call->conn->params.key->payload.data[0];
212 memcpy(&iv, token->kad->session_key, sizeof(iv));
214 sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
215 skcipher_request_set_tfm(req, call->conn->cipher);
216 skcipher_request_set_callback(req, 0, NULL, NULL);
217 skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
218 crypto_skcipher_encrypt(req);
220 /* we want to encrypt the skbuff in-place */
221 nsg = skb_cow_data(skb, 0, &trailer);
223 if (nsg < 0 || nsg > 16)
226 len = data_size + call->conn->size_align - 1;
227 len &= ~(call->conn->size_align - 1);
229 sg_init_table(sg, nsg);
230 skb_to_sgvec(skb, sg, 0, len);
231 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
232 crypto_skcipher_encrypt(req);
238 skcipher_request_zero(req);
243 * checksum an RxRPC packet header
245 static int rxkad_secure_packet(struct rxrpc_call *call,
250 struct rxrpc_skb_priv *sp;
251 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
252 struct rxrpc_crypt iv;
253 struct scatterlist sg;
259 _enter("{%d{%x}},{#%u},%zu,",
260 call->debug_id, key_serial(call->conn->params.key),
261 sp->hdr.seq, data_size);
263 if (!call->conn->cipher)
266 ret = key_validate(call->conn->params.key);
270 /* continue encrypting from where we left off */
271 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
273 /* calculate the security checksum */
274 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
275 x |= sp->hdr.seq & 0x3fffffff;
276 call->crypto_buf[0] = htonl(call->call_id);
277 call->crypto_buf[1] = htonl(x);
279 sg_init_one(&sg, call->crypto_buf, 8);
280 skcipher_request_set_tfm(req, call->conn->cipher);
281 skcipher_request_set_callback(req, 0, NULL, NULL);
282 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
283 crypto_skcipher_encrypt(req);
284 skcipher_request_zero(req);
286 y = ntohl(call->crypto_buf[1]);
287 y = (y >> 16) & 0xffff;
289 y = 1; /* zero checksums are not permitted */
292 switch (call->conn->params.security_level) {
293 case RXRPC_SECURITY_PLAIN:
296 case RXRPC_SECURITY_AUTH:
297 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr);
299 case RXRPC_SECURITY_ENCRYPT:
300 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
308 _leave(" = %d [set %hx]", ret, y);
313 * decrypt partial encryption on a packet (level 1 security)
315 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
316 unsigned int offset, unsigned int len,
319 struct rxkad_level1_hdr sechdr;
320 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
321 struct rxrpc_crypt iv;
322 struct scatterlist sg[16];
323 struct sk_buff *trailer;
332 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
337 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
338 * directly into the target buffer.
340 nsg = skb_cow_data(skb, 0, &trailer);
341 if (nsg < 0 || nsg > 16)
344 sg_init_table(sg, nsg);
345 skb_to_sgvec(skb, sg, offset, 8);
347 /* start the decryption afresh */
348 memset(&iv, 0, sizeof(iv));
350 skcipher_request_set_tfm(req, call->conn->cipher);
351 skcipher_request_set_callback(req, 0, NULL, NULL);
352 skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
353 crypto_skcipher_decrypt(req);
354 skcipher_request_zero(req);
356 /* Extract the decrypted packet length */
357 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
358 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
362 offset += sizeof(sechdr);
363 len -= sizeof(sechdr);
365 buf = ntohl(sechdr.data_size);
366 data_size = buf & 0xffff;
369 check ^= seq ^ call->call_id;
372 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
377 if (data_size > len) {
378 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
383 _leave(" = 0 [dlen=%x]", data_size);
388 rxrpc_send_abort_packet(call);
392 _leave(" = -ENOMEM");
397 * wholly decrypt a packet (level 2 security)
399 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
400 unsigned int offset, unsigned int len,
403 const struct rxrpc_key_token *token;
404 struct rxkad_level2_hdr sechdr;
405 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
406 struct rxrpc_crypt iv;
407 struct scatterlist _sg[4], *sg;
408 struct sk_buff *trailer;
414 _enter(",{%d}", skb->len);
417 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
422 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
423 * directly into the target buffer.
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 skb_to_sgvec(skb, sg, offset, len);
439 /* decrypt from the session key */
440 token = call->conn->params.key->payload.data[0];
441 memcpy(&iv, token->kad->session_key, sizeof(iv));
443 skcipher_request_set_tfm(req, call->conn->cipher);
444 skcipher_request_set_callback(req, 0, NULL, NULL);
445 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
446 crypto_skcipher_decrypt(req);
447 skcipher_request_zero(req);
451 /* Extract the decrypted packet length */
452 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
453 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
457 offset += sizeof(sechdr);
458 len -= sizeof(sechdr);
460 buf = ntohl(sechdr.data_size);
461 data_size = buf & 0xffff;
464 check ^= seq ^ call->call_id;
467 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
472 if (data_size > len) {
473 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
478 _leave(" = 0 [dlen=%x]", data_size);
483 rxrpc_send_abort_packet(call);
487 _leave(" = -ENOMEM");
492 * Verify the security on a received packet or subpacket (if part of a
495 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
496 unsigned int offset, unsigned int len,
497 rxrpc_seq_t seq, u16 expected_cksum)
499 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
500 struct rxrpc_crypt iv;
501 struct scatterlist sg;
506 _enter("{%d{%x}},{#%u}",
507 call->debug_id, key_serial(call->conn->params.key), seq);
509 if (!call->conn->cipher)
512 /* continue encrypting from where we left off */
513 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
515 /* validate the security checksum */
516 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
517 x |= seq & 0x3fffffff;
518 call->crypto_buf[0] = htonl(call->call_id);
519 call->crypto_buf[1] = htonl(x);
521 sg_init_one(&sg, call->crypto_buf, 8);
522 skcipher_request_set_tfm(req, call->conn->cipher);
523 skcipher_request_set_callback(req, 0, NULL, NULL);
524 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
525 crypto_skcipher_encrypt(req);
526 skcipher_request_zero(req);
528 y = ntohl(call->crypto_buf[1]);
529 cksum = (y >> 16) & 0xffff;
531 cksum = 1; /* zero checksums are not permitted */
533 if (cksum != expected_cksum) {
534 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
539 switch (call->conn->params.security_level) {
540 case RXRPC_SECURITY_PLAIN:
542 case RXRPC_SECURITY_AUTH:
543 return rxkad_verify_packet_1(call, skb, offset, len, seq);
544 case RXRPC_SECURITY_ENCRYPT:
545 return rxkad_verify_packet_2(call, skb, offset, len, seq);
552 rxrpc_send_abort_packet(call);
557 * Locate the data contained in a packet that was partially encrypted.
559 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
560 unsigned int *_offset, unsigned int *_len)
562 struct rxkad_level1_hdr sechdr;
564 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
566 *_offset += sizeof(sechdr);
567 *_len = ntohl(sechdr.data_size) & 0xffff;
571 * Locate the data contained in a packet that was completely encrypted.
573 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
574 unsigned int *_offset, unsigned int *_len)
576 struct rxkad_level2_hdr sechdr;
578 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
580 *_offset += sizeof(sechdr);
581 *_len = ntohl(sechdr.data_size) & 0xffff;
585 * Locate the data contained in an already decrypted packet.
587 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
588 unsigned int *_offset, unsigned int *_len)
590 switch (call->conn->params.security_level) {
591 case RXRPC_SECURITY_AUTH:
592 rxkad_locate_data_1(call, skb, _offset, _len);
594 case RXRPC_SECURITY_ENCRYPT:
595 rxkad_locate_data_2(call, skb, _offset, _len);
605 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
607 struct rxkad_challenge challenge;
608 struct rxrpc_wire_header whdr;
615 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
617 ret = key_validate(conn->params.key);
621 get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
623 challenge.version = htonl(2);
624 challenge.nonce = htonl(conn->security_nonce);
625 challenge.min_level = htonl(0);
626 challenge.__padding = 0;
628 msg.msg_name = &conn->params.peer->srx.transport.sin;
629 msg.msg_namelen = sizeof(conn->params.peer->srx.transport.sin);
630 msg.msg_control = NULL;
631 msg.msg_controllen = 0;
634 whdr.epoch = htonl(conn->proto.epoch);
635 whdr.cid = htonl(conn->proto.cid);
638 whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
639 whdr.flags = conn->out_clientflag;
641 whdr.securityIndex = conn->security_ix;
643 whdr.serviceId = htons(conn->params.service_id);
645 iov[0].iov_base = &whdr;
646 iov[0].iov_len = sizeof(whdr);
647 iov[1].iov_base = &challenge;
648 iov[1].iov_len = sizeof(challenge);
650 len = iov[0].iov_len + iov[1].iov_len;
652 serial = atomic_inc_return(&conn->serial);
653 whdr.serial = htonl(serial);
654 _proto("Tx CHALLENGE %%%u", serial);
656 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
658 _debug("sendmsg failed: %d", ret);
667 * send a Kerberos security response
669 static int rxkad_send_response(struct rxrpc_connection *conn,
670 struct rxrpc_host_header *hdr,
671 struct rxkad_response *resp,
672 const struct rxkad_key *s2)
674 struct rxrpc_wire_header whdr;
683 msg.msg_name = &conn->params.peer->srx.transport.sin;
684 msg.msg_namelen = sizeof(conn->params.peer->srx.transport.sin);
685 msg.msg_control = NULL;
686 msg.msg_controllen = 0;
689 memset(&whdr, 0, sizeof(whdr));
690 whdr.epoch = htonl(hdr->epoch);
691 whdr.cid = htonl(hdr->cid);
692 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
693 whdr.flags = conn->out_clientflag;
694 whdr.securityIndex = hdr->securityIndex;
695 whdr.serviceId = htons(hdr->serviceId);
697 iov[0].iov_base = &whdr;
698 iov[0].iov_len = sizeof(whdr);
699 iov[1].iov_base = resp;
700 iov[1].iov_len = sizeof(*resp);
701 iov[2].iov_base = (void *)s2->ticket;
702 iov[2].iov_len = s2->ticket_len;
704 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
706 serial = atomic_inc_return(&conn->serial);
707 whdr.serial = htonl(serial);
708 _proto("Tx RESPONSE %%%u", serial);
710 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
712 _debug("sendmsg failed: %d", ret);
721 * calculate the response checksum
723 static void rxkad_calc_response_checksum(struct rxkad_response *response)
727 u8 *p = (u8 *) response;
729 for (loop = sizeof(*response); loop > 0; loop--)
730 csum = csum * 0x10204081 + *p++;
732 response->encrypted.checksum = htonl(csum);
736 * encrypt the response packet
738 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
739 struct rxkad_response *resp,
740 const struct rxkad_key *s2)
742 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
743 struct rxrpc_crypt iv;
744 struct scatterlist sg[1];
746 /* continue encrypting from where we left off */
747 memcpy(&iv, s2->session_key, sizeof(iv));
749 sg_init_table(sg, 1);
750 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
751 skcipher_request_set_tfm(req, conn->cipher);
752 skcipher_request_set_callback(req, 0, NULL, NULL);
753 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
754 crypto_skcipher_encrypt(req);
755 skcipher_request_zero(req);
759 * respond to a challenge packet
761 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
765 const struct rxrpc_key_token *token;
766 struct rxkad_challenge challenge;
767 struct rxkad_response resp
768 __attribute__((aligned(8))); /* must be aligned for crypto */
769 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
771 u32 version, nonce, min_level, abort_code;
774 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
776 eproto = tracepoint_string("chall_no_key");
777 abort_code = RX_PROTOCOL_ERROR;
778 if (!conn->params.key)
781 abort_code = RXKADEXPIRED;
782 ret = key_validate(conn->params.key);
786 eproto = tracepoint_string("chall_short");
787 abort_code = RXKADPACKETSHORT;
788 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
789 &challenge, sizeof(challenge)) < 0)
792 version = ntohl(challenge.version);
793 nonce = ntohl(challenge.nonce);
794 min_level = ntohl(challenge.min_level);
796 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
797 sp->hdr.serial, version, nonce, min_level);
799 eproto = tracepoint_string("chall_ver");
800 abort_code = RXKADINCONSISTENCY;
801 if (version != RXKAD_VERSION)
804 abort_code = RXKADLEVELFAIL;
806 if (conn->params.security_level < min_level)
809 token = conn->params.key->payload.data[0];
811 /* build the response packet */
812 memset(&resp, 0, sizeof(resp));
814 resp.version = htonl(RXKAD_VERSION);
815 resp.encrypted.epoch = htonl(conn->proto.epoch);
816 resp.encrypted.cid = htonl(conn->proto.cid);
817 resp.encrypted.securityIndex = htonl(conn->security_ix);
818 resp.encrypted.inc_nonce = htonl(nonce + 1);
819 resp.encrypted.level = htonl(conn->params.security_level);
820 resp.kvno = htonl(token->kad->kvno);
821 resp.ticket_len = htonl(token->kad->ticket_len);
823 resp.encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
824 resp.encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
825 resp.encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
826 resp.encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
828 /* calculate the response checksum and then do the encryption */
829 rxkad_calc_response_checksum(&resp);
830 rxkad_encrypt_response(conn, &resp, token->kad);
831 return rxkad_send_response(conn, &sp->hdr, &resp, token->kad);
834 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
837 *_abort_code = abort_code;
842 * decrypt the kerberos IV ticket in the response
844 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
846 void *ticket, size_t ticket_len,
847 struct rxrpc_crypt *_session_key,
851 struct skcipher_request *req;
852 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
853 struct rxrpc_crypt iv, key;
854 struct scatterlist sg[1];
862 u8 *p, *q, *name, *end;
864 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
868 ret = key_validate(conn->server_key);
872 abort_code = RXKADEXPIRED;
875 abort_code = RXKADNOAUTH;
880 ASSERT(conn->server_key->payload.data[0] != NULL);
881 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
883 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
886 req = skcipher_request_alloc(conn->server_key->payload.data[0],
889 goto temporary_error;
891 sg_init_one(&sg[0], ticket, ticket_len);
892 skcipher_request_set_callback(req, 0, NULL, NULL);
893 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
894 crypto_skcipher_decrypt(req);
895 skcipher_request_free(req);
898 end = p + ticket_len;
903 eproto = tracepoint_string("rxkad_bad_"#field); \
904 q = memchr(p, 0, end - p); \
905 if (!q || q - p > (field##_SZ)) \
914 /* extract the ticket flags */
915 _debug("KIV FLAGS: %x", *p);
916 little_endian = *p & 1;
919 /* extract the authentication name */
921 _debug("KIV ANAME: %s", name);
923 /* extract the principal's instance */
925 _debug("KIV INST : %s", name);
927 /* extract the principal's authentication domain */
929 _debug("KIV REALM: %s", name);
931 eproto = tracepoint_string("rxkad_bad_len");
932 if (end - p < 4 + 8 + 4 + 2)
935 /* get the IPv4 address of the entity that requested the ticket */
936 memcpy(&addr, p, sizeof(addr));
938 _debug("KIV ADDR : %pI4", &addr);
940 /* get the session key from the ticket */
941 memcpy(&key, p, sizeof(key));
943 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
944 memcpy(_session_key, &key, sizeof(key));
946 /* get the ticket's lifetime */
947 life = *p++ * 5 * 60;
948 _debug("KIV LIFE : %u", life);
950 /* get the issue time of the ticket */
953 memcpy(&stamp, p, 4);
954 issue = le32_to_cpu(stamp);
957 memcpy(&stamp, p, 4);
958 issue = be32_to_cpu(stamp);
962 _debug("KIV ISSUE: %lx [%lx]", issue, now);
964 /* check the ticket is in date */
966 abort_code = RXKADNOAUTH;
971 if (issue < now - life) {
972 abort_code = RXKADEXPIRED;
977 *_expiry = issue + life;
979 /* get the service name */
981 _debug("KIV SNAME: %s", name);
983 /* get the service instance name */
985 _debug("KIV SINST: %s", name);
989 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
990 abort_code = RXKADBADTICKET;
993 *_abort_code = abort_code;
1000 * decrypt the response packet
1002 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1003 struct rxkad_response *resp,
1004 const struct rxrpc_crypt *session_key)
1006 SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci);
1007 struct scatterlist sg[1];
1008 struct rxrpc_crypt iv;
1010 _enter(",,%08x%08x",
1011 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1013 ASSERT(rxkad_ci != NULL);
1015 mutex_lock(&rxkad_ci_mutex);
1016 if (crypto_skcipher_setkey(rxkad_ci, session_key->x,
1017 sizeof(*session_key)) < 0)
1020 memcpy(&iv, session_key, sizeof(iv));
1022 sg_init_table(sg, 1);
1023 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1024 skcipher_request_set_tfm(req, rxkad_ci);
1025 skcipher_request_set_callback(req, 0, NULL, NULL);
1026 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1027 crypto_skcipher_decrypt(req);
1028 skcipher_request_zero(req);
1030 mutex_unlock(&rxkad_ci_mutex);
1038 static int rxkad_verify_response(struct rxrpc_connection *conn,
1039 struct sk_buff *skb,
1042 struct rxkad_response response
1043 __attribute__((aligned(8))); /* must be aligned for crypto */
1044 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1045 struct rxrpc_crypt session_key;
1049 u32 abort_code, version, kvno, ticket_len, level;
1053 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1055 eproto = tracepoint_string("rxkad_rsp_short");
1056 abort_code = RXKADPACKETSHORT;
1057 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1058 &response, sizeof(response)) < 0)
1059 goto protocol_error;
1060 if (!pskb_pull(skb, sizeof(response)))
1063 version = ntohl(response.version);
1064 ticket_len = ntohl(response.ticket_len);
1065 kvno = ntohl(response.kvno);
1066 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1067 sp->hdr.serial, version, kvno, ticket_len);
1069 eproto = tracepoint_string("rxkad_rsp_ver");
1070 abort_code = RXKADINCONSISTENCY;
1071 if (version != RXKAD_VERSION)
1072 goto protocol_error;
1074 eproto = tracepoint_string("rxkad_rsp_tktlen");
1075 abort_code = RXKADTICKETLEN;
1076 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1077 goto protocol_error;
1079 eproto = tracepoint_string("rxkad_rsp_unkkey");
1080 abort_code = RXKADUNKNOWNKEY;
1081 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1082 goto protocol_error;
1084 /* extract the kerberos ticket and decrypt and decode it */
1086 ticket = kmalloc(ticket_len, GFP_NOFS);
1088 goto temporary_error;
1090 eproto = tracepoint_string("rxkad_tkt_short");
1091 abort_code = RXKADPACKETSHORT;
1092 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1093 ticket, ticket_len) < 0)
1094 goto protocol_error_free;
1096 ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1097 &expiry, _abort_code);
1099 goto temporary_error_free;
1101 /* use the session key from inside the ticket to decrypt the
1103 rxkad_decrypt_response(conn, &response, &session_key);
1105 eproto = tracepoint_string("rxkad_rsp_param");
1106 abort_code = RXKADSEALEDINCON;
1107 if (ntohl(response.encrypted.epoch) != conn->proto.epoch)
1108 goto protocol_error_free;
1109 if (ntohl(response.encrypted.cid) != conn->proto.cid)
1110 goto protocol_error_free;
1111 if (ntohl(response.encrypted.securityIndex) != conn->security_ix)
1112 goto protocol_error_free;
1113 csum = response.encrypted.checksum;
1114 response.encrypted.checksum = 0;
1115 rxkad_calc_response_checksum(&response);
1116 eproto = tracepoint_string("rxkad_rsp_csum");
1117 if (response.encrypted.checksum != csum)
1118 goto protocol_error_free;
1120 spin_lock(&conn->channel_lock);
1121 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1122 struct rxrpc_call *call;
1123 u32 call_id = ntohl(response.encrypted.call_id[i]);
1125 eproto = tracepoint_string("rxkad_rsp_callid");
1126 if (call_id > INT_MAX)
1127 goto protocol_error_unlock;
1129 eproto = tracepoint_string("rxkad_rsp_callctr");
1130 if (call_id < conn->channels[i].call_counter)
1131 goto protocol_error_unlock;
1133 eproto = tracepoint_string("rxkad_rsp_callst");
1134 if (call_id > conn->channels[i].call_counter) {
1135 call = rcu_dereference_protected(
1136 conn->channels[i].call,
1137 lockdep_is_held(&conn->channel_lock));
1138 if (call && call->state < RXRPC_CALL_COMPLETE)
1139 goto protocol_error_unlock;
1140 conn->channels[i].call_counter = call_id;
1143 spin_unlock(&conn->channel_lock);
1145 eproto = tracepoint_string("rxkad_rsp_seq");
1146 abort_code = RXKADOUTOFSEQUENCE;
1147 if (ntohl(response.encrypted.inc_nonce) != conn->security_nonce + 1)
1148 goto protocol_error_free;
1150 eproto = tracepoint_string("rxkad_rsp_level");
1151 abort_code = RXKADLEVELFAIL;
1152 level = ntohl(response.encrypted.level);
1153 if (level > RXRPC_SECURITY_ENCRYPT)
1154 goto protocol_error_free;
1155 conn->params.security_level = level;
1157 /* create a key to hold the security data and expiration time - after
1158 * this the connection security can be handled in exactly the same way
1159 * as for a client connection */
1160 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1162 goto temporary_error_free;
1168 protocol_error_unlock:
1169 spin_unlock(&conn->channel_lock);
1170 protocol_error_free:
1173 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1174 *_abort_code = abort_code;
1177 temporary_error_free:
1180 /* Ignore the response packet if we got a temporary error such as
1181 * ENOMEM. We just want to send the challenge again. Note that we
1182 * also come out this way if the ticket decryption fails.
1188 * clear the connection security
1190 static void rxkad_clear(struct rxrpc_connection *conn)
1195 crypto_free_skcipher(conn->cipher);
1199 * Initialise the rxkad security service.
1201 static int rxkad_init(void)
1203 /* pin the cipher we need so that the crypto layer doesn't invoke
1204 * keventd to go get it */
1205 rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
1206 return PTR_ERR_OR_ZERO(rxkad_ci);
1210 * Clean up the rxkad security service.
1212 static void rxkad_exit(void)
1215 crypto_free_skcipher(rxkad_ci);
1219 * RxRPC Kerberos-based security
1221 const struct rxrpc_security rxkad = {
1223 .security_index = RXRPC_SECURITY_RXKAD,
1226 .init_connection_security = rxkad_init_connection_security,
1227 .prime_packet_security = rxkad_prime_packet_security,
1228 .secure_packet = rxkad_secure_packet,
1229 .verify_packet = rxkad_verify_packet,
1230 .locate_data = rxkad_locate_data,
1231 .issue_challenge = rxkad_issue_challenge,
1232 .respond_to_challenge = rxkad_respond_to_challenge,
1233 .verify_response = rxkad_verify_response,
1234 .clear = rxkad_clear,