1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Kerberos-based RxRPC security
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <crypto/skcipher.h>
11 #include <linux/module.h>
12 #include <linux/net.h>
13 #include <linux/skbuff.h>
14 #include <linux/udp.h>
15 #include <linux/scatterlist.h>
16 #include <linux/ctype.h>
17 #include <linux/slab.h>
19 #include <net/af_rxrpc.h>
20 #include <keys/rxrpc-type.h>
21 #include "ar-internal.h"
23 #define RXKAD_VERSION 2
24 #define MAXKRB5TICKETLEN 1024
25 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
26 #define ANAME_SZ 40 /* size of authentication name */
27 #define INST_SZ 40 /* size of principal's instance */
28 #define REALM_SZ 40 /* size of principal's auth domain */
29 #define SNAME_SZ 40 /* size of service name */
31 struct rxkad_level1_hdr {
32 __be32 data_size; /* true data size (excluding padding) */
35 struct rxkad_level2_hdr {
36 __be32 data_size; /* true data size (excluding padding) */
37 __be32 checksum; /* decrypted data checksum */
41 * this holds a pinned cipher so that keventd doesn't get called by the cipher
42 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
45 static struct crypto_sync_skcipher *rxkad_ci;
46 static DEFINE_MUTEX(rxkad_ci_mutex);
49 * initialise connection security
51 static int rxkad_init_connection_security(struct rxrpc_connection *conn)
53 struct crypto_sync_skcipher *ci;
54 struct rxrpc_key_token *token;
57 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
59 token = conn->params.key->payload.data[0];
60 conn->security_ix = token->security_index;
62 ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
69 if (crypto_sync_skcipher_setkey(ci, token->kad->session_key,
70 sizeof(token->kad->session_key)) < 0)
73 switch (conn->params.security_level) {
74 case RXRPC_SECURITY_PLAIN:
76 case RXRPC_SECURITY_AUTH:
78 conn->security_size = sizeof(struct rxkad_level1_hdr);
80 case RXRPC_SECURITY_ENCRYPT:
82 conn->security_size = sizeof(struct rxkad_level2_hdr);
97 * prime the encryption state with the invariant parts of a connection's
100 static int rxkad_prime_packet_security(struct rxrpc_connection *conn)
102 struct rxrpc_key_token *token;
103 SYNC_SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
104 struct scatterlist sg;
105 struct rxrpc_crypt iv;
107 size_t tmpsize = 4 * sizeof(__be32);
111 if (!conn->params.key)
114 tmpbuf = kmalloc(tmpsize, GFP_KERNEL);
118 token = conn->params.key->payload.data[0];
119 memcpy(&iv, token->kad->session_key, sizeof(iv));
121 tmpbuf[0] = htonl(conn->proto.epoch);
122 tmpbuf[1] = htonl(conn->proto.cid);
124 tmpbuf[3] = htonl(conn->security_ix);
126 sg_init_one(&sg, tmpbuf, tmpsize);
127 skcipher_request_set_sync_tfm(req, conn->cipher);
128 skcipher_request_set_callback(req, 0, NULL, NULL);
129 skcipher_request_set_crypt(req, &sg, &sg, tmpsize, iv.x);
130 crypto_skcipher_encrypt(req);
131 skcipher_request_zero(req);
133 memcpy(&conn->csum_iv, tmpbuf + 2, sizeof(conn->csum_iv));
140 * partially encrypt a packet (level 1 security)
142 static int rxkad_secure_packet_auth(const struct rxrpc_call *call,
146 struct skcipher_request *req)
148 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
149 struct rxkad_level1_hdr hdr;
150 struct rxrpc_crypt iv;
151 struct scatterlist sg;
156 check = sp->hdr.seq ^ call->call_id;
157 data_size |= (u32)check << 16;
159 hdr.data_size = htonl(data_size);
160 memcpy(sechdr, &hdr, sizeof(hdr));
162 /* start the encryption afresh */
163 memset(&iv, 0, sizeof(iv));
165 sg_init_one(&sg, sechdr, 8);
166 skcipher_request_set_sync_tfm(req, call->conn->cipher);
167 skcipher_request_set_callback(req, 0, NULL, NULL);
168 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
169 crypto_skcipher_encrypt(req);
170 skcipher_request_zero(req);
177 * wholly encrypt a packet (level 2 security)
179 static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call,
183 struct skcipher_request *req)
185 const struct rxrpc_key_token *token;
186 struct rxkad_level2_hdr rxkhdr;
187 struct rxrpc_skb_priv *sp;
188 struct rxrpc_crypt iv;
189 struct scatterlist sg[16];
190 struct sk_buff *trailer;
200 check = sp->hdr.seq ^ call->call_id;
202 rxkhdr.data_size = htonl(data_size | (u32)check << 16);
204 memcpy(sechdr, &rxkhdr, sizeof(rxkhdr));
206 /* encrypt from the session key */
207 token = call->conn->params.key->payload.data[0];
208 memcpy(&iv, token->kad->session_key, sizeof(iv));
210 sg_init_one(&sg[0], sechdr, sizeof(rxkhdr));
211 skcipher_request_set_sync_tfm(req, call->conn->cipher);
212 skcipher_request_set_callback(req, 0, NULL, NULL);
213 skcipher_request_set_crypt(req, &sg[0], &sg[0], sizeof(rxkhdr), iv.x);
214 crypto_skcipher_encrypt(req);
216 /* we want to encrypt the skbuff in-place */
217 nsg = skb_cow_data(skb, 0, &trailer);
219 if (nsg < 0 || nsg > 16)
222 len = data_size + call->conn->size_align - 1;
223 len &= ~(call->conn->size_align - 1);
225 sg_init_table(sg, nsg);
226 err = skb_to_sgvec(skb, sg, 0, len);
227 if (unlikely(err < 0))
229 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
230 crypto_skcipher_encrypt(req);
236 skcipher_request_zero(req);
241 * checksum an RxRPC packet header
243 static int rxkad_secure_packet(struct rxrpc_call *call,
248 struct rxrpc_skb_priv *sp;
249 SYNC_SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
250 struct rxrpc_crypt iv;
251 struct scatterlist sg;
257 _enter("{%d{%x}},{#%u},%zu,",
258 call->debug_id, key_serial(call->conn->params.key),
259 sp->hdr.seq, data_size);
261 if (!call->conn->cipher)
264 ret = key_validate(call->conn->params.key);
268 /* continue encrypting from where we left off */
269 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
271 /* calculate the security checksum */
272 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
273 x |= sp->hdr.seq & 0x3fffffff;
274 call->crypto_buf[0] = htonl(call->call_id);
275 call->crypto_buf[1] = htonl(x);
277 sg_init_one(&sg, call->crypto_buf, 8);
278 skcipher_request_set_sync_tfm(req, call->conn->cipher);
279 skcipher_request_set_callback(req, 0, NULL, NULL);
280 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
281 crypto_skcipher_encrypt(req);
282 skcipher_request_zero(req);
284 y = ntohl(call->crypto_buf[1]);
285 y = (y >> 16) & 0xffff;
287 y = 1; /* zero checksums are not permitted */
290 switch (call->conn->params.security_level) {
291 case RXRPC_SECURITY_PLAIN:
294 case RXRPC_SECURITY_AUTH:
295 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr,
298 case RXRPC_SECURITY_ENCRYPT:
299 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
307 _leave(" = %d [set %hx]", ret, y);
312 * decrypt partial encryption on a packet (level 1 security)
314 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
315 unsigned int offset, unsigned int len,
317 struct skcipher_request *req)
319 struct rxkad_level1_hdr sechdr;
320 struct rxrpc_crypt iv;
321 struct scatterlist sg[16];
322 struct sk_buff *trailer;
331 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
336 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
337 * directly into the target buffer.
339 nsg = skb_cow_data(skb, 0, &trailer);
340 if (nsg < 0 || nsg > 16)
343 sg_init_table(sg, nsg);
344 ret = skb_to_sgvec(skb, sg, offset, 8);
345 if (unlikely(ret < 0))
348 /* start the decryption afresh */
349 memset(&iv, 0, sizeof(iv));
351 skcipher_request_set_sync_tfm(req, call->conn->cipher);
352 skcipher_request_set_callback(req, 0, NULL, NULL);
353 skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
354 crypto_skcipher_decrypt(req);
355 skcipher_request_zero(req);
357 /* Extract the decrypted packet length */
358 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
359 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
363 offset += sizeof(sechdr);
364 len -= sizeof(sechdr);
366 buf = ntohl(sechdr.data_size);
367 data_size = buf & 0xffff;
370 check ^= seq ^ call->call_id;
373 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
378 if (data_size > len) {
379 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
384 _leave(" = 0 [dlen=%x]", data_size);
389 rxrpc_send_abort_packet(call);
393 _leave(" = -ENOMEM");
398 * wholly decrypt a packet (level 2 security)
400 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
401 unsigned int offset, unsigned int len,
403 struct skcipher_request *req)
405 const struct rxrpc_key_token *token;
406 struct rxkad_level2_hdr sechdr;
407 struct rxrpc_crypt iv;
408 struct scatterlist _sg[4], *sg;
409 struct sk_buff *trailer;
415 _enter(",{%d}", skb->len);
418 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
423 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
424 * directly into the target buffer.
426 nsg = skb_cow_data(skb, 0, &trailer);
431 if (unlikely(nsg > 4)) {
432 sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO);
437 sg_init_table(sg, nsg);
438 ret = skb_to_sgvec(skb, sg, offset, len);
439 if (unlikely(ret < 0)) {
445 /* decrypt from the session key */
446 token = call->conn->params.key->payload.data[0];
447 memcpy(&iv, token->kad->session_key, sizeof(iv));
449 skcipher_request_set_sync_tfm(req, call->conn->cipher);
450 skcipher_request_set_callback(req, 0, NULL, NULL);
451 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
452 crypto_skcipher_decrypt(req);
453 skcipher_request_zero(req);
457 /* Extract the decrypted packet length */
458 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
459 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
463 offset += sizeof(sechdr);
464 len -= sizeof(sechdr);
466 buf = ntohl(sechdr.data_size);
467 data_size = buf & 0xffff;
470 check ^= seq ^ call->call_id;
473 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
478 if (data_size > len) {
479 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
484 _leave(" = 0 [dlen=%x]", data_size);
489 rxrpc_send_abort_packet(call);
493 _leave(" = -ENOMEM");
498 * Verify the security on a received packet or subpacket (if part of a
501 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
502 unsigned int offset, unsigned int len,
503 rxrpc_seq_t seq, u16 expected_cksum)
505 SYNC_SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
506 struct rxrpc_crypt iv;
507 struct scatterlist sg;
512 _enter("{%d{%x}},{#%u}",
513 call->debug_id, key_serial(call->conn->params.key), seq);
515 if (!call->conn->cipher)
518 /* continue encrypting from where we left off */
519 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
521 /* validate the security checksum */
522 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
523 x |= seq & 0x3fffffff;
524 call->crypto_buf[0] = htonl(call->call_id);
525 call->crypto_buf[1] = htonl(x);
527 sg_init_one(&sg, call->crypto_buf, 8);
528 skcipher_request_set_sync_tfm(req, call->conn->cipher);
529 skcipher_request_set_callback(req, 0, NULL, NULL);
530 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
531 crypto_skcipher_encrypt(req);
532 skcipher_request_zero(req);
534 y = ntohl(call->crypto_buf[1]);
535 cksum = (y >> 16) & 0xffff;
537 cksum = 1; /* zero checksums are not permitted */
539 if (cksum != expected_cksum) {
540 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
545 switch (call->conn->params.security_level) {
546 case RXRPC_SECURITY_PLAIN:
548 case RXRPC_SECURITY_AUTH:
549 return rxkad_verify_packet_1(call, skb, offset, len, seq, req);
550 case RXRPC_SECURITY_ENCRYPT:
551 return rxkad_verify_packet_2(call, skb, offset, len, seq, req);
558 rxrpc_send_abort_packet(call);
563 * Locate the data contained in a packet that was partially encrypted.
565 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
566 unsigned int *_offset, unsigned int *_len)
568 struct rxkad_level1_hdr sechdr;
570 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
572 *_offset += sizeof(sechdr);
573 *_len = ntohl(sechdr.data_size) & 0xffff;
577 * Locate the data contained in a packet that was completely encrypted.
579 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
580 unsigned int *_offset, unsigned int *_len)
582 struct rxkad_level2_hdr sechdr;
584 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
586 *_offset += sizeof(sechdr);
587 *_len = ntohl(sechdr.data_size) & 0xffff;
591 * Locate the data contained in an already decrypted packet.
593 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
594 unsigned int *_offset, unsigned int *_len)
596 switch (call->conn->params.security_level) {
597 case RXRPC_SECURITY_AUTH:
598 rxkad_locate_data_1(call, skb, _offset, _len);
600 case RXRPC_SECURITY_ENCRYPT:
601 rxkad_locate_data_2(call, skb, _offset, _len);
611 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
613 struct rxkad_challenge challenge;
614 struct rxrpc_wire_header whdr;
621 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
623 ret = key_validate(conn->params.key);
627 get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
629 challenge.version = htonl(2);
630 challenge.nonce = htonl(conn->security_nonce);
631 challenge.min_level = htonl(0);
632 challenge.__padding = 0;
634 msg.msg_name = &conn->params.peer->srx.transport;
635 msg.msg_namelen = conn->params.peer->srx.transport_len;
636 msg.msg_control = NULL;
637 msg.msg_controllen = 0;
640 whdr.epoch = htonl(conn->proto.epoch);
641 whdr.cid = htonl(conn->proto.cid);
644 whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
645 whdr.flags = conn->out_clientflag;
647 whdr.securityIndex = conn->security_ix;
649 whdr.serviceId = htons(conn->service_id);
651 iov[0].iov_base = &whdr;
652 iov[0].iov_len = sizeof(whdr);
653 iov[1].iov_base = &challenge;
654 iov[1].iov_len = sizeof(challenge);
656 len = iov[0].iov_len + iov[1].iov_len;
658 serial = atomic_inc_return(&conn->serial);
659 whdr.serial = htonl(serial);
660 _proto("Tx CHALLENGE %%%u", serial);
662 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
664 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
665 rxrpc_tx_point_rxkad_challenge);
669 conn->params.peer->last_tx_at = ktime_get_seconds();
670 trace_rxrpc_tx_packet(conn->debug_id, &whdr,
671 rxrpc_tx_point_rxkad_challenge);
677 * send a Kerberos security response
679 static int rxkad_send_response(struct rxrpc_connection *conn,
680 struct rxrpc_host_header *hdr,
681 struct rxkad_response *resp,
682 const struct rxkad_key *s2)
684 struct rxrpc_wire_header whdr;
693 msg.msg_name = &conn->params.peer->srx.transport;
694 msg.msg_namelen = conn->params.peer->srx.transport_len;
695 msg.msg_control = NULL;
696 msg.msg_controllen = 0;
699 memset(&whdr, 0, sizeof(whdr));
700 whdr.epoch = htonl(hdr->epoch);
701 whdr.cid = htonl(hdr->cid);
702 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
703 whdr.flags = conn->out_clientflag;
704 whdr.securityIndex = hdr->securityIndex;
705 whdr.serviceId = htons(hdr->serviceId);
707 iov[0].iov_base = &whdr;
708 iov[0].iov_len = sizeof(whdr);
709 iov[1].iov_base = resp;
710 iov[1].iov_len = sizeof(*resp);
711 iov[2].iov_base = (void *)s2->ticket;
712 iov[2].iov_len = s2->ticket_len;
714 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
716 serial = atomic_inc_return(&conn->serial);
717 whdr.serial = htonl(serial);
718 _proto("Tx RESPONSE %%%u", serial);
720 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
722 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
723 rxrpc_tx_point_rxkad_response);
727 conn->params.peer->last_tx_at = ktime_get_seconds();
733 * calculate the response checksum
735 static void rxkad_calc_response_checksum(struct rxkad_response *response)
739 u8 *p = (u8 *) response;
741 for (loop = sizeof(*response); loop > 0; loop--)
742 csum = csum * 0x10204081 + *p++;
744 response->encrypted.checksum = htonl(csum);
748 * encrypt the response packet
750 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
751 struct rxkad_response *resp,
752 const struct rxkad_key *s2)
754 SYNC_SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
755 struct rxrpc_crypt iv;
756 struct scatterlist sg[1];
758 /* continue encrypting from where we left off */
759 memcpy(&iv, s2->session_key, sizeof(iv));
761 sg_init_table(sg, 1);
762 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
763 skcipher_request_set_sync_tfm(req, conn->cipher);
764 skcipher_request_set_callback(req, 0, NULL, NULL);
765 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
766 crypto_skcipher_encrypt(req);
767 skcipher_request_zero(req);
771 * respond to a challenge packet
773 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
777 const struct rxrpc_key_token *token;
778 struct rxkad_challenge challenge;
779 struct rxkad_response *resp;
780 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
782 u32 version, nonce, min_level, abort_code;
785 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
787 eproto = tracepoint_string("chall_no_key");
788 abort_code = RX_PROTOCOL_ERROR;
789 if (!conn->params.key)
792 abort_code = RXKADEXPIRED;
793 ret = key_validate(conn->params.key);
797 eproto = tracepoint_string("chall_short");
798 abort_code = RXKADPACKETSHORT;
799 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
800 &challenge, sizeof(challenge)) < 0)
803 version = ntohl(challenge.version);
804 nonce = ntohl(challenge.nonce);
805 min_level = ntohl(challenge.min_level);
807 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
808 sp->hdr.serial, version, nonce, min_level);
810 eproto = tracepoint_string("chall_ver");
811 abort_code = RXKADINCONSISTENCY;
812 if (version != RXKAD_VERSION)
815 abort_code = RXKADLEVELFAIL;
817 if (conn->params.security_level < min_level)
820 token = conn->params.key->payload.data[0];
822 /* build the response packet */
823 resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
827 resp->version = htonl(RXKAD_VERSION);
828 resp->encrypted.epoch = htonl(conn->proto.epoch);
829 resp->encrypted.cid = htonl(conn->proto.cid);
830 resp->encrypted.securityIndex = htonl(conn->security_ix);
831 resp->encrypted.inc_nonce = htonl(nonce + 1);
832 resp->encrypted.level = htonl(conn->params.security_level);
833 resp->kvno = htonl(token->kad->kvno);
834 resp->ticket_len = htonl(token->kad->ticket_len);
835 resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
836 resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
837 resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
838 resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
840 /* calculate the response checksum and then do the encryption */
841 rxkad_calc_response_checksum(resp);
842 rxkad_encrypt_response(conn, resp, token->kad);
843 ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
848 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
851 *_abort_code = abort_code;
856 * decrypt the kerberos IV ticket in the response
858 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
860 void *ticket, size_t ticket_len,
861 struct rxrpc_crypt *_session_key,
865 struct skcipher_request *req;
866 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
867 struct rxrpc_crypt iv, key;
868 struct scatterlist sg[1];
876 u8 *p, *q, *name, *end;
878 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
882 ret = key_validate(conn->server_key);
886 abort_code = RXKADEXPIRED;
889 abort_code = RXKADNOAUTH;
894 ASSERT(conn->server_key->payload.data[0] != NULL);
895 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
897 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
900 req = skcipher_request_alloc(conn->server_key->payload.data[0],
903 goto temporary_error;
905 sg_init_one(&sg[0], ticket, ticket_len);
906 skcipher_request_set_callback(req, 0, NULL, NULL);
907 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
908 crypto_skcipher_decrypt(req);
909 skcipher_request_free(req);
912 end = p + ticket_len;
917 eproto = tracepoint_string("rxkad_bad_"#field); \
918 q = memchr(p, 0, end - p); \
919 if (!q || q - p > (field##_SZ)) \
928 /* extract the ticket flags */
929 _debug("KIV FLAGS: %x", *p);
930 little_endian = *p & 1;
933 /* extract the authentication name */
935 _debug("KIV ANAME: %s", name);
937 /* extract the principal's instance */
939 _debug("KIV INST : %s", name);
941 /* extract the principal's authentication domain */
943 _debug("KIV REALM: %s", name);
945 eproto = tracepoint_string("rxkad_bad_len");
946 if (end - p < 4 + 8 + 4 + 2)
949 /* get the IPv4 address of the entity that requested the ticket */
950 memcpy(&addr, p, sizeof(addr));
952 _debug("KIV ADDR : %pI4", &addr);
954 /* get the session key from the ticket */
955 memcpy(&key, p, sizeof(key));
957 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
958 memcpy(_session_key, &key, sizeof(key));
960 /* get the ticket's lifetime */
961 life = *p++ * 5 * 60;
962 _debug("KIV LIFE : %u", life);
964 /* get the issue time of the ticket */
967 memcpy(&stamp, p, 4);
968 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
971 memcpy(&stamp, p, 4);
972 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
975 now = ktime_get_real_seconds();
976 _debug("KIV ISSUE: %llx [%llx]", issue, now);
978 /* check the ticket is in date */
980 abort_code = RXKADNOAUTH;
985 if (issue < now - life) {
986 abort_code = RXKADEXPIRED;
991 *_expiry = issue + life;
993 /* get the service name */
995 _debug("KIV SNAME: %s", name);
997 /* get the service instance name */
999 _debug("KIV SINST: %s", name);
1003 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1004 abort_code = RXKADBADTICKET;
1007 *_abort_code = abort_code;
1014 * decrypt the response packet
1016 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1017 struct rxkad_response *resp,
1018 const struct rxrpc_crypt *session_key)
1020 SYNC_SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci);
1021 struct scatterlist sg[1];
1022 struct rxrpc_crypt iv;
1024 _enter(",,%08x%08x",
1025 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1027 ASSERT(rxkad_ci != NULL);
1029 mutex_lock(&rxkad_ci_mutex);
1030 if (crypto_sync_skcipher_setkey(rxkad_ci, session_key->x,
1031 sizeof(*session_key)) < 0)
1034 memcpy(&iv, session_key, sizeof(iv));
1036 sg_init_table(sg, 1);
1037 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1038 skcipher_request_set_sync_tfm(req, rxkad_ci);
1039 skcipher_request_set_callback(req, 0, NULL, NULL);
1040 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1041 crypto_skcipher_decrypt(req);
1042 skcipher_request_zero(req);
1044 mutex_unlock(&rxkad_ci_mutex);
1052 static int rxkad_verify_response(struct rxrpc_connection *conn,
1053 struct sk_buff *skb,
1056 struct rxkad_response *response;
1057 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1058 struct rxrpc_crypt session_key;
1062 u32 abort_code, version, kvno, ticket_len, level;
1066 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1069 response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
1071 goto temporary_error;
1073 eproto = tracepoint_string("rxkad_rsp_short");
1074 abort_code = RXKADPACKETSHORT;
1075 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1076 response, sizeof(*response)) < 0)
1077 goto protocol_error;
1078 if (!pskb_pull(skb, sizeof(*response)))
1081 version = ntohl(response->version);
1082 ticket_len = ntohl(response->ticket_len);
1083 kvno = ntohl(response->kvno);
1084 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1085 sp->hdr.serial, version, kvno, ticket_len);
1087 eproto = tracepoint_string("rxkad_rsp_ver");
1088 abort_code = RXKADINCONSISTENCY;
1089 if (version != RXKAD_VERSION)
1090 goto protocol_error;
1092 eproto = tracepoint_string("rxkad_rsp_tktlen");
1093 abort_code = RXKADTICKETLEN;
1094 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1095 goto protocol_error;
1097 eproto = tracepoint_string("rxkad_rsp_unkkey");
1098 abort_code = RXKADUNKNOWNKEY;
1099 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1100 goto protocol_error;
1102 /* extract the kerberos ticket and decrypt and decode it */
1104 ticket = kmalloc(ticket_len, GFP_NOFS);
1106 goto temporary_error;
1108 eproto = tracepoint_string("rxkad_tkt_short");
1109 abort_code = RXKADPACKETSHORT;
1110 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1111 ticket, ticket_len) < 0)
1112 goto protocol_error_free;
1114 ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1115 &expiry, _abort_code);
1117 goto temporary_error_free_resp;
1119 /* use the session key from inside the ticket to decrypt the
1121 rxkad_decrypt_response(conn, response, &session_key);
1123 eproto = tracepoint_string("rxkad_rsp_param");
1124 abort_code = RXKADSEALEDINCON;
1125 if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
1126 goto protocol_error_free;
1127 if (ntohl(response->encrypted.cid) != conn->proto.cid)
1128 goto protocol_error_free;
1129 if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
1130 goto protocol_error_free;
1131 csum = response->encrypted.checksum;
1132 response->encrypted.checksum = 0;
1133 rxkad_calc_response_checksum(response);
1134 eproto = tracepoint_string("rxkad_rsp_csum");
1135 if (response->encrypted.checksum != csum)
1136 goto protocol_error_free;
1138 spin_lock(&conn->channel_lock);
1139 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1140 struct rxrpc_call *call;
1141 u32 call_id = ntohl(response->encrypted.call_id[i]);
1143 eproto = tracepoint_string("rxkad_rsp_callid");
1144 if (call_id > INT_MAX)
1145 goto protocol_error_unlock;
1147 eproto = tracepoint_string("rxkad_rsp_callctr");
1148 if (call_id < conn->channels[i].call_counter)
1149 goto protocol_error_unlock;
1151 eproto = tracepoint_string("rxkad_rsp_callst");
1152 if (call_id > conn->channels[i].call_counter) {
1153 call = rcu_dereference_protected(
1154 conn->channels[i].call,
1155 lockdep_is_held(&conn->channel_lock));
1156 if (call && call->state < RXRPC_CALL_COMPLETE)
1157 goto protocol_error_unlock;
1158 conn->channels[i].call_counter = call_id;
1161 spin_unlock(&conn->channel_lock);
1163 eproto = tracepoint_string("rxkad_rsp_seq");
1164 abort_code = RXKADOUTOFSEQUENCE;
1165 if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1)
1166 goto protocol_error_free;
1168 eproto = tracepoint_string("rxkad_rsp_level");
1169 abort_code = RXKADLEVELFAIL;
1170 level = ntohl(response->encrypted.level);
1171 if (level > RXRPC_SECURITY_ENCRYPT)
1172 goto protocol_error_free;
1173 conn->params.security_level = level;
1175 /* create a key to hold the security data and expiration time - after
1176 * this the connection security can be handled in exactly the same way
1177 * as for a client connection */
1178 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1180 goto temporary_error_free_ticket;
1187 protocol_error_unlock:
1188 spin_unlock(&conn->channel_lock);
1189 protocol_error_free:
1193 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1194 *_abort_code = abort_code;
1197 temporary_error_free_ticket:
1199 temporary_error_free_resp:
1202 /* Ignore the response packet if we got a temporary error such as
1203 * ENOMEM. We just want to send the challenge again. Note that we
1204 * also come out this way if the ticket decryption fails.
1210 * clear the connection security
1212 static void rxkad_clear(struct rxrpc_connection *conn)
1217 crypto_free_sync_skcipher(conn->cipher);
1221 * Initialise the rxkad security service.
1223 static int rxkad_init(void)
1225 /* pin the cipher we need so that the crypto layer doesn't invoke
1226 * keventd to go get it */
1227 rxkad_ci = crypto_alloc_sync_skcipher("pcbc(fcrypt)", 0, 0);
1228 return PTR_ERR_OR_ZERO(rxkad_ci);
1232 * Clean up the rxkad security service.
1234 static void rxkad_exit(void)
1237 crypto_free_sync_skcipher(rxkad_ci);
1241 * RxRPC Kerberos-based security
1243 const struct rxrpc_security rxkad = {
1245 .security_index = RXRPC_SECURITY_RXKAD,
1248 .init_connection_security = rxkad_init_connection_security,
1249 .prime_packet_security = rxkad_prime_packet_security,
1250 .secure_packet = rxkad_secure_packet,
1251 .verify_packet = rxkad_verify_packet,
1252 .locate_data = rxkad_locate_data,
1253 .issue_challenge = rxkad_issue_challenge,
1254 .respond_to_challenge = rxkad_respond_to_challenge,
1255 .verify_response = rxkad_verify_response,
1256 .clear = rxkad_clear,