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 err = skb_to_sgvec(skb, sg, 0, len);
231 if (unlikely(err < 0))
233 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
234 crypto_skcipher_encrypt(req);
240 skcipher_request_zero(req);
245 * checksum an RxRPC packet header
247 static int rxkad_secure_packet(struct rxrpc_call *call,
252 struct rxrpc_skb_priv *sp;
253 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
254 struct rxrpc_crypt iv;
255 struct scatterlist sg;
261 _enter("{%d{%x}},{#%u},%zu,",
262 call->debug_id, key_serial(call->conn->params.key),
263 sp->hdr.seq, data_size);
265 if (!call->conn->cipher)
268 ret = key_validate(call->conn->params.key);
272 /* continue encrypting from where we left off */
273 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
275 /* calculate the security checksum */
276 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
277 x |= sp->hdr.seq & 0x3fffffff;
278 call->crypto_buf[0] = htonl(call->call_id);
279 call->crypto_buf[1] = htonl(x);
281 sg_init_one(&sg, call->crypto_buf, 8);
282 skcipher_request_set_tfm(req, call->conn->cipher);
283 skcipher_request_set_callback(req, 0, NULL, NULL);
284 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
285 crypto_skcipher_encrypt(req);
286 skcipher_request_zero(req);
288 y = ntohl(call->crypto_buf[1]);
289 y = (y >> 16) & 0xffff;
291 y = 1; /* zero checksums are not permitted */
294 switch (call->conn->params.security_level) {
295 case RXRPC_SECURITY_PLAIN:
298 case RXRPC_SECURITY_AUTH:
299 ret = rxkad_secure_packet_auth(call, skb, data_size, sechdr);
301 case RXRPC_SECURITY_ENCRYPT:
302 ret = rxkad_secure_packet_encrypt(call, skb, data_size,
310 _leave(" = %d [set %hx]", ret, y);
315 * decrypt partial encryption on a packet (level 1 security)
317 static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
318 unsigned int offset, unsigned int len,
321 struct rxkad_level1_hdr sechdr;
322 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
323 struct rxrpc_crypt iv;
324 struct scatterlist sg[16];
325 struct sk_buff *trailer;
334 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_hdr", "V1H",
339 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
340 * directly into the target buffer.
342 nsg = skb_cow_data(skb, 0, &trailer);
343 if (nsg < 0 || nsg > 16)
346 sg_init_table(sg, nsg);
347 ret = skb_to_sgvec(skb, sg, offset, 8);
348 if (unlikely(ret < 0))
351 /* start the decryption afresh */
352 memset(&iv, 0, sizeof(iv));
354 skcipher_request_set_tfm(req, call->conn->cipher);
355 skcipher_request_set_callback(req, 0, NULL, NULL);
356 skcipher_request_set_crypt(req, sg, sg, 8, iv.x);
357 crypto_skcipher_decrypt(req);
358 skcipher_request_zero(req);
360 /* Extract the decrypted packet length */
361 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
362 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_len", "XV1",
366 offset += sizeof(sechdr);
367 len -= sizeof(sechdr);
369 buf = ntohl(sechdr.data_size);
370 data_size = buf & 0xffff;
373 check ^= seq ^ call->call_id;
376 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_check", "V1C",
381 if (data_size > len) {
382 aborted = rxrpc_abort_eproto(call, skb, "rxkad_1_datalen", "V1L",
387 _leave(" = 0 [dlen=%x]", data_size);
392 rxrpc_send_abort_packet(call);
396 _leave(" = -ENOMEM");
401 * wholly decrypt a packet (level 2 security)
403 static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
404 unsigned int offset, unsigned int len,
407 const struct rxrpc_key_token *token;
408 struct rxkad_level2_hdr sechdr;
409 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
410 struct rxrpc_crypt iv;
411 struct scatterlist _sg[4], *sg;
412 struct sk_buff *trailer;
418 _enter(",{%d}", skb->len);
421 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_hdr", "V2H",
426 /* Decrypt the skbuff in-place. TODO: We really want to decrypt
427 * directly into the target buffer.
429 nsg = skb_cow_data(skb, 0, &trailer);
434 if (unlikely(nsg > 4)) {
435 sg = kmalloc_array(nsg, sizeof(*sg), GFP_NOIO);
440 sg_init_table(sg, nsg);
441 ret = skb_to_sgvec(skb, sg, offset, len);
442 if (unlikely(ret < 0)) {
448 /* decrypt from the session key */
449 token = call->conn->params.key->payload.data[0];
450 memcpy(&iv, token->kad->session_key, sizeof(iv));
452 skcipher_request_set_tfm(req, call->conn->cipher);
453 skcipher_request_set_callback(req, 0, NULL, NULL);
454 skcipher_request_set_crypt(req, sg, sg, len, iv.x);
455 crypto_skcipher_decrypt(req);
456 skcipher_request_zero(req);
460 /* Extract the decrypted packet length */
461 if (skb_copy_bits(skb, offset, &sechdr, sizeof(sechdr)) < 0) {
462 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_len", "XV2",
466 offset += sizeof(sechdr);
467 len -= sizeof(sechdr);
469 buf = ntohl(sechdr.data_size);
470 data_size = buf & 0xffff;
473 check ^= seq ^ call->call_id;
476 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_check", "V2C",
481 if (data_size > len) {
482 aborted = rxrpc_abort_eproto(call, skb, "rxkad_2_datalen", "V2L",
487 _leave(" = 0 [dlen=%x]", data_size);
492 rxrpc_send_abort_packet(call);
496 _leave(" = -ENOMEM");
501 * Verify the security on a received packet or subpacket (if part of a
504 static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
505 unsigned int offset, unsigned int len,
506 rxrpc_seq_t seq, u16 expected_cksum)
508 SKCIPHER_REQUEST_ON_STACK(req, call->conn->cipher);
509 struct rxrpc_crypt iv;
510 struct scatterlist sg;
515 _enter("{%d{%x}},{#%u}",
516 call->debug_id, key_serial(call->conn->params.key), seq);
518 if (!call->conn->cipher)
521 /* continue encrypting from where we left off */
522 memcpy(&iv, call->conn->csum_iv.x, sizeof(iv));
524 /* validate the security checksum */
525 x = (call->cid & RXRPC_CHANNELMASK) << (32 - RXRPC_CIDSHIFT);
526 x |= seq & 0x3fffffff;
527 call->crypto_buf[0] = htonl(call->call_id);
528 call->crypto_buf[1] = htonl(x);
530 sg_init_one(&sg, call->crypto_buf, 8);
531 skcipher_request_set_tfm(req, call->conn->cipher);
532 skcipher_request_set_callback(req, 0, NULL, NULL);
533 skcipher_request_set_crypt(req, &sg, &sg, 8, iv.x);
534 crypto_skcipher_encrypt(req);
535 skcipher_request_zero(req);
537 y = ntohl(call->crypto_buf[1]);
538 cksum = (y >> 16) & 0xffff;
540 cksum = 1; /* zero checksums are not permitted */
542 if (cksum != expected_cksum) {
543 aborted = rxrpc_abort_eproto(call, skb, "rxkad_csum", "VCK",
548 switch (call->conn->params.security_level) {
549 case RXRPC_SECURITY_PLAIN:
551 case RXRPC_SECURITY_AUTH:
552 return rxkad_verify_packet_1(call, skb, offset, len, seq);
553 case RXRPC_SECURITY_ENCRYPT:
554 return rxkad_verify_packet_2(call, skb, offset, len, seq);
561 rxrpc_send_abort_packet(call);
566 * Locate the data contained in a packet that was partially encrypted.
568 static void rxkad_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
569 unsigned int *_offset, unsigned int *_len)
571 struct rxkad_level1_hdr sechdr;
573 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
575 *_offset += sizeof(sechdr);
576 *_len = ntohl(sechdr.data_size) & 0xffff;
580 * Locate the data contained in a packet that was completely encrypted.
582 static void rxkad_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
583 unsigned int *_offset, unsigned int *_len)
585 struct rxkad_level2_hdr sechdr;
587 if (skb_copy_bits(skb, *_offset, &sechdr, sizeof(sechdr)) < 0)
589 *_offset += sizeof(sechdr);
590 *_len = ntohl(sechdr.data_size) & 0xffff;
594 * Locate the data contained in an already decrypted packet.
596 static void rxkad_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
597 unsigned int *_offset, unsigned int *_len)
599 switch (call->conn->params.security_level) {
600 case RXRPC_SECURITY_AUTH:
601 rxkad_locate_data_1(call, skb, _offset, _len);
603 case RXRPC_SECURITY_ENCRYPT:
604 rxkad_locate_data_2(call, skb, _offset, _len);
614 static int rxkad_issue_challenge(struct rxrpc_connection *conn)
616 struct rxkad_challenge challenge;
617 struct rxrpc_wire_header whdr;
624 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
626 ret = key_validate(conn->params.key);
630 get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
632 challenge.version = htonl(2);
633 challenge.nonce = htonl(conn->security_nonce);
634 challenge.min_level = htonl(0);
635 challenge.__padding = 0;
637 msg.msg_name = &conn->params.peer->srx.transport;
638 msg.msg_namelen = conn->params.peer->srx.transport_len;
639 msg.msg_control = NULL;
640 msg.msg_controllen = 0;
643 whdr.epoch = htonl(conn->proto.epoch);
644 whdr.cid = htonl(conn->proto.cid);
647 whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
648 whdr.flags = conn->out_clientflag;
650 whdr.securityIndex = conn->security_ix;
652 whdr.serviceId = htons(conn->service_id);
654 iov[0].iov_base = &whdr;
655 iov[0].iov_len = sizeof(whdr);
656 iov[1].iov_base = &challenge;
657 iov[1].iov_len = sizeof(challenge);
659 len = iov[0].iov_len + iov[1].iov_len;
661 serial = atomic_inc_return(&conn->serial);
662 whdr.serial = htonl(serial);
663 _proto("Tx CHALLENGE %%%u", serial);
665 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
667 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
668 rxrpc_tx_fail_conn_challenge);
672 conn->params.peer->last_tx_at = ktime_get_seconds();
678 * send a Kerberos security response
680 static int rxkad_send_response(struct rxrpc_connection *conn,
681 struct rxrpc_host_header *hdr,
682 struct rxkad_response *resp,
683 const struct rxkad_key *s2)
685 struct rxrpc_wire_header whdr;
694 msg.msg_name = &conn->params.peer->srx.transport;
695 msg.msg_namelen = conn->params.peer->srx.transport_len;
696 msg.msg_control = NULL;
697 msg.msg_controllen = 0;
700 memset(&whdr, 0, sizeof(whdr));
701 whdr.epoch = htonl(hdr->epoch);
702 whdr.cid = htonl(hdr->cid);
703 whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
704 whdr.flags = conn->out_clientflag;
705 whdr.securityIndex = hdr->securityIndex;
706 whdr.serviceId = htons(hdr->serviceId);
708 iov[0].iov_base = &whdr;
709 iov[0].iov_len = sizeof(whdr);
710 iov[1].iov_base = resp;
711 iov[1].iov_len = sizeof(*resp);
712 iov[2].iov_base = (void *)s2->ticket;
713 iov[2].iov_len = s2->ticket_len;
715 len = iov[0].iov_len + iov[1].iov_len + iov[2].iov_len;
717 serial = atomic_inc_return(&conn->serial);
718 whdr.serial = htonl(serial);
719 _proto("Tx RESPONSE %%%u", serial);
721 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 3, len);
723 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
724 rxrpc_tx_fail_conn_response);
728 conn->params.peer->last_tx_at = ktime_get_seconds();
734 * calculate the response checksum
736 static void rxkad_calc_response_checksum(struct rxkad_response *response)
740 u8 *p = (u8 *) response;
742 for (loop = sizeof(*response); loop > 0; loop--)
743 csum = csum * 0x10204081 + *p++;
745 response->encrypted.checksum = htonl(csum);
749 * encrypt the response packet
751 static void rxkad_encrypt_response(struct rxrpc_connection *conn,
752 struct rxkad_response *resp,
753 const struct rxkad_key *s2)
755 SKCIPHER_REQUEST_ON_STACK(req, conn->cipher);
756 struct rxrpc_crypt iv;
757 struct scatterlist sg[1];
759 /* continue encrypting from where we left off */
760 memcpy(&iv, s2->session_key, sizeof(iv));
762 sg_init_table(sg, 1);
763 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
764 skcipher_request_set_tfm(req, conn->cipher);
765 skcipher_request_set_callback(req, 0, NULL, NULL);
766 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
767 crypto_skcipher_encrypt(req);
768 skcipher_request_zero(req);
772 * respond to a challenge packet
774 static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
778 const struct rxrpc_key_token *token;
779 struct rxkad_challenge challenge;
780 struct rxkad_response *resp;
781 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
783 u32 version, nonce, min_level, abort_code;
786 _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
788 eproto = tracepoint_string("chall_no_key");
789 abort_code = RX_PROTOCOL_ERROR;
790 if (!conn->params.key)
793 abort_code = RXKADEXPIRED;
794 ret = key_validate(conn->params.key);
798 eproto = tracepoint_string("chall_short");
799 abort_code = RXKADPACKETSHORT;
800 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
801 &challenge, sizeof(challenge)) < 0)
804 version = ntohl(challenge.version);
805 nonce = ntohl(challenge.nonce);
806 min_level = ntohl(challenge.min_level);
808 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
809 sp->hdr.serial, version, nonce, min_level);
811 eproto = tracepoint_string("chall_ver");
812 abort_code = RXKADINCONSISTENCY;
813 if (version != RXKAD_VERSION)
816 abort_code = RXKADLEVELFAIL;
818 if (conn->params.security_level < min_level)
821 token = conn->params.key->payload.data[0];
823 /* build the response packet */
824 resp = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
828 resp->version = htonl(RXKAD_VERSION);
829 resp->encrypted.epoch = htonl(conn->proto.epoch);
830 resp->encrypted.cid = htonl(conn->proto.cid);
831 resp->encrypted.securityIndex = htonl(conn->security_ix);
832 resp->encrypted.inc_nonce = htonl(nonce + 1);
833 resp->encrypted.level = htonl(conn->params.security_level);
834 resp->kvno = htonl(token->kad->kvno);
835 resp->ticket_len = htonl(token->kad->ticket_len);
836 resp->encrypted.call_id[0] = htonl(conn->channels[0].call_counter);
837 resp->encrypted.call_id[1] = htonl(conn->channels[1].call_counter);
838 resp->encrypted.call_id[2] = htonl(conn->channels[2].call_counter);
839 resp->encrypted.call_id[3] = htonl(conn->channels[3].call_counter);
841 /* calculate the response checksum and then do the encryption */
842 rxkad_calc_response_checksum(resp);
843 rxkad_encrypt_response(conn, resp, token->kad);
844 ret = rxkad_send_response(conn, &sp->hdr, resp, token->kad);
849 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
852 *_abort_code = abort_code;
857 * decrypt the kerberos IV ticket in the response
859 static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
861 void *ticket, size_t ticket_len,
862 struct rxrpc_crypt *_session_key,
866 struct skcipher_request *req;
867 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
868 struct rxrpc_crypt iv, key;
869 struct scatterlist sg[1];
877 u8 *p, *q, *name, *end;
879 _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
883 ret = key_validate(conn->server_key);
887 abort_code = RXKADEXPIRED;
890 abort_code = RXKADNOAUTH;
895 ASSERT(conn->server_key->payload.data[0] != NULL);
896 ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
898 memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
901 req = skcipher_request_alloc(conn->server_key->payload.data[0],
904 goto temporary_error;
906 sg_init_one(&sg[0], ticket, ticket_len);
907 skcipher_request_set_callback(req, 0, NULL, NULL);
908 skcipher_request_set_crypt(req, sg, sg, ticket_len, iv.x);
909 crypto_skcipher_decrypt(req);
910 skcipher_request_free(req);
913 end = p + ticket_len;
918 eproto = tracepoint_string("rxkad_bad_"#field); \
919 q = memchr(p, 0, end - p); \
920 if (!q || q - p > (field##_SZ)) \
929 /* extract the ticket flags */
930 _debug("KIV FLAGS: %x", *p);
931 little_endian = *p & 1;
934 /* extract the authentication name */
936 _debug("KIV ANAME: %s", name);
938 /* extract the principal's instance */
940 _debug("KIV INST : %s", name);
942 /* extract the principal's authentication domain */
944 _debug("KIV REALM: %s", name);
946 eproto = tracepoint_string("rxkad_bad_len");
947 if (end - p < 4 + 8 + 4 + 2)
950 /* get the IPv4 address of the entity that requested the ticket */
951 memcpy(&addr, p, sizeof(addr));
953 _debug("KIV ADDR : %pI4", &addr);
955 /* get the session key from the ticket */
956 memcpy(&key, p, sizeof(key));
958 _debug("KIV KEY : %08x %08x", ntohl(key.n[0]), ntohl(key.n[1]));
959 memcpy(_session_key, &key, sizeof(key));
961 /* get the ticket's lifetime */
962 life = *p++ * 5 * 60;
963 _debug("KIV LIFE : %u", life);
965 /* get the issue time of the ticket */
968 memcpy(&stamp, p, 4);
969 issue = rxrpc_u32_to_time64(le32_to_cpu(stamp));
972 memcpy(&stamp, p, 4);
973 issue = rxrpc_u32_to_time64(be32_to_cpu(stamp));
976 now = ktime_get_real_seconds();
977 _debug("KIV ISSUE: %llx [%llx]", issue, now);
979 /* check the ticket is in date */
981 abort_code = RXKADNOAUTH;
986 if (issue < now - life) {
987 abort_code = RXKADEXPIRED;
992 *_expiry = issue + life;
994 /* get the service name */
996 _debug("KIV SNAME: %s", name);
998 /* get the service instance name */
1000 _debug("KIV SINST: %s", name);
1004 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1005 abort_code = RXKADBADTICKET;
1008 *_abort_code = abort_code;
1015 * decrypt the response packet
1017 static void rxkad_decrypt_response(struct rxrpc_connection *conn,
1018 struct rxkad_response *resp,
1019 const struct rxrpc_crypt *session_key)
1021 SKCIPHER_REQUEST_ON_STACK(req, rxkad_ci);
1022 struct scatterlist sg[1];
1023 struct rxrpc_crypt iv;
1025 _enter(",,%08x%08x",
1026 ntohl(session_key->n[0]), ntohl(session_key->n[1]));
1028 ASSERT(rxkad_ci != NULL);
1030 mutex_lock(&rxkad_ci_mutex);
1031 if (crypto_skcipher_setkey(rxkad_ci, session_key->x,
1032 sizeof(*session_key)) < 0)
1035 memcpy(&iv, session_key, sizeof(iv));
1037 sg_init_table(sg, 1);
1038 sg_set_buf(sg, &resp->encrypted, sizeof(resp->encrypted));
1039 skcipher_request_set_tfm(req, rxkad_ci);
1040 skcipher_request_set_callback(req, 0, NULL, NULL);
1041 skcipher_request_set_crypt(req, sg, sg, sizeof(resp->encrypted), iv.x);
1042 crypto_skcipher_decrypt(req);
1043 skcipher_request_zero(req);
1045 mutex_unlock(&rxkad_ci_mutex);
1053 static int rxkad_verify_response(struct rxrpc_connection *conn,
1054 struct sk_buff *skb,
1057 struct rxkad_response *response;
1058 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
1059 struct rxrpc_crypt session_key;
1063 u32 abort_code, version, kvno, ticket_len, level;
1067 _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
1070 response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
1072 goto temporary_error;
1074 eproto = tracepoint_string("rxkad_rsp_short");
1075 abort_code = RXKADPACKETSHORT;
1076 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1077 response, sizeof(*response)) < 0)
1078 goto protocol_error;
1079 if (!pskb_pull(skb, sizeof(*response)))
1082 version = ntohl(response->version);
1083 ticket_len = ntohl(response->ticket_len);
1084 kvno = ntohl(response->kvno);
1085 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1086 sp->hdr.serial, version, kvno, ticket_len);
1088 eproto = tracepoint_string("rxkad_rsp_ver");
1089 abort_code = RXKADINCONSISTENCY;
1090 if (version != RXKAD_VERSION)
1091 goto protocol_error;
1093 eproto = tracepoint_string("rxkad_rsp_tktlen");
1094 abort_code = RXKADTICKETLEN;
1095 if (ticket_len < 4 || ticket_len > MAXKRB5TICKETLEN)
1096 goto protocol_error;
1098 eproto = tracepoint_string("rxkad_rsp_unkkey");
1099 abort_code = RXKADUNKNOWNKEY;
1100 if (kvno >= RXKAD_TKT_TYPE_KERBEROS_V5)
1101 goto protocol_error;
1103 /* extract the kerberos ticket and decrypt and decode it */
1105 ticket = kmalloc(ticket_len, GFP_NOFS);
1107 goto temporary_error;
1109 eproto = tracepoint_string("rxkad_tkt_short");
1110 abort_code = RXKADPACKETSHORT;
1111 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
1112 ticket, ticket_len) < 0)
1113 goto protocol_error_free;
1115 ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
1116 &expiry, _abort_code);
1118 goto temporary_error_free_resp;
1120 /* use the session key from inside the ticket to decrypt the
1122 rxkad_decrypt_response(conn, response, &session_key);
1124 eproto = tracepoint_string("rxkad_rsp_param");
1125 abort_code = RXKADSEALEDINCON;
1126 if (ntohl(response->encrypted.epoch) != conn->proto.epoch)
1127 goto protocol_error_free;
1128 if (ntohl(response->encrypted.cid) != conn->proto.cid)
1129 goto protocol_error_free;
1130 if (ntohl(response->encrypted.securityIndex) != conn->security_ix)
1131 goto protocol_error_free;
1132 csum = response->encrypted.checksum;
1133 response->encrypted.checksum = 0;
1134 rxkad_calc_response_checksum(response);
1135 eproto = tracepoint_string("rxkad_rsp_csum");
1136 if (response->encrypted.checksum != csum)
1137 goto protocol_error_free;
1139 spin_lock(&conn->channel_lock);
1140 for (i = 0; i < RXRPC_MAXCALLS; i++) {
1141 struct rxrpc_call *call;
1142 u32 call_id = ntohl(response->encrypted.call_id[i]);
1144 eproto = tracepoint_string("rxkad_rsp_callid");
1145 if (call_id > INT_MAX)
1146 goto protocol_error_unlock;
1148 eproto = tracepoint_string("rxkad_rsp_callctr");
1149 if (call_id < conn->channels[i].call_counter)
1150 goto protocol_error_unlock;
1152 eproto = tracepoint_string("rxkad_rsp_callst");
1153 if (call_id > conn->channels[i].call_counter) {
1154 call = rcu_dereference_protected(
1155 conn->channels[i].call,
1156 lockdep_is_held(&conn->channel_lock));
1157 if (call && call->state < RXRPC_CALL_COMPLETE)
1158 goto protocol_error_unlock;
1159 conn->channels[i].call_counter = call_id;
1162 spin_unlock(&conn->channel_lock);
1164 eproto = tracepoint_string("rxkad_rsp_seq");
1165 abort_code = RXKADOUTOFSEQUENCE;
1166 if (ntohl(response->encrypted.inc_nonce) != conn->security_nonce + 1)
1167 goto protocol_error_free;
1169 eproto = tracepoint_string("rxkad_rsp_level");
1170 abort_code = RXKADLEVELFAIL;
1171 level = ntohl(response->encrypted.level);
1172 if (level > RXRPC_SECURITY_ENCRYPT)
1173 goto protocol_error_free;
1174 conn->params.security_level = level;
1176 /* create a key to hold the security data and expiration time - after
1177 * this the connection security can be handled in exactly the same way
1178 * as for a client connection */
1179 ret = rxrpc_get_server_data_key(conn, &session_key, expiry, kvno);
1181 goto temporary_error_free_ticket;
1188 protocol_error_unlock:
1189 spin_unlock(&conn->channel_lock);
1190 protocol_error_free:
1194 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
1195 *_abort_code = abort_code;
1198 temporary_error_free_ticket:
1200 temporary_error_free_resp:
1203 /* Ignore the response packet if we got a temporary error such as
1204 * ENOMEM. We just want to send the challenge again. Note that we
1205 * also come out this way if the ticket decryption fails.
1211 * clear the connection security
1213 static void rxkad_clear(struct rxrpc_connection *conn)
1218 crypto_free_skcipher(conn->cipher);
1222 * Initialise the rxkad security service.
1224 static int rxkad_init(void)
1226 /* pin the cipher we need so that the crypto layer doesn't invoke
1227 * keventd to go get it */
1228 rxkad_ci = crypto_alloc_skcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC);
1229 return PTR_ERR_OR_ZERO(rxkad_ci);
1233 * Clean up the rxkad security service.
1235 static void rxkad_exit(void)
1238 crypto_free_skcipher(rxkad_ci);
1242 * RxRPC Kerberos-based security
1244 const struct rxrpc_security rxkad = {
1246 .security_index = RXRPC_SECURITY_RXKAD,
1249 .init_connection_security = rxkad_init_connection_security,
1250 .prime_packet_security = rxkad_prime_packet_security,
1251 .secure_packet = rxkad_secure_packet,
1252 .verify_packet = rxkad_verify_packet,
1253 .locate_data = rxkad_locate_data,
1254 .issue_challenge = rxkad_issue_challenge,
1255 .respond_to_challenge = rxkad_respond_to_challenge,
1256 .verify_response = rxkad_verify_response,
1257 .clear = rxkad_clear,