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>
20 #include <net/af_rxrpc.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 */
32 module_param_named(debug
, rxrpc_debug
, uint
, S_IWUSR
| S_IRUGO
);
33 MODULE_PARM_DESC(rxrpc_debug
, "rxkad debugging mask");
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 */
44 MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos)");
45 MODULE_AUTHOR("Red Hat, Inc.");
46 MODULE_LICENSE("GPL");
49 * this holds a pinned cipher so that keventd doesn't get called by the cipher
50 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
53 static struct crypto_blkcipher
*rxkad_ci
;
54 static DEFINE_MUTEX(rxkad_ci_mutex
);
57 * initialise connection security
59 static int rxkad_init_connection_security(struct rxrpc_connection
*conn
)
61 struct rxrpc_key_payload
*payload
;
62 struct crypto_blkcipher
*ci
;
65 _enter("{%d},{%x}", conn
->debug_id
, key_serial(conn
->key
));
67 payload
= conn
->key
->payload
.data
;
68 conn
->security_ix
= payload
->k
.security_index
;
70 ci
= crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC
);
77 if (crypto_blkcipher_setkey(ci
, payload
->k
.session_key
,
78 sizeof(payload
->k
.session_key
)) < 0)
81 switch (conn
->security_level
) {
82 case RXRPC_SECURITY_PLAIN
:
84 case RXRPC_SECURITY_AUTH
:
86 conn
->security_size
= sizeof(struct rxkad_level1_hdr
);
87 conn
->header_size
+= sizeof(struct rxkad_level1_hdr
);
89 case RXRPC_SECURITY_ENCRYPT
:
91 conn
->security_size
= sizeof(struct rxkad_level2_hdr
);
92 conn
->header_size
+= sizeof(struct rxkad_level2_hdr
);
102 _leave(" = %d", ret
);
107 * prime the encryption state with the invariant parts of a connection's
110 static void rxkad_prime_packet_security(struct rxrpc_connection
*conn
)
112 struct rxrpc_key_payload
*payload
;
113 struct blkcipher_desc desc
;
114 struct scatterlist sg
[2];
115 struct rxrpc_crypt iv
;
118 } tmpbuf
__attribute__((aligned(16))); /* must all be in same page */
125 payload
= conn
->key
->payload
.data
;
126 memcpy(&iv
, payload
->k
.session_key
, sizeof(iv
));
128 desc
.tfm
= conn
->cipher
;
132 tmpbuf
.x
[0] = conn
->epoch
;
133 tmpbuf
.x
[1] = conn
->cid
;
135 tmpbuf
.x
[3] = htonl(conn
->security_ix
);
137 memset(sg
, 0, sizeof(sg
));
138 sg_set_buf(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
139 sg_set_buf(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
140 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
142 memcpy(&conn
->csum_iv
, &tmpbuf
.x
[2], sizeof(conn
->csum_iv
));
143 ASSERTCMP(conn
->csum_iv
.n
[0], ==, tmpbuf
.x
[2]);
149 * partially encrypt a packet (level 1 security)
151 static int rxkad_secure_packet_auth(const struct rxrpc_call
*call
,
156 struct rxrpc_skb_priv
*sp
;
157 struct blkcipher_desc desc
;
158 struct rxrpc_crypt iv
;
159 struct scatterlist sg
[2];
161 struct rxkad_level1_hdr hdr
;
162 __be32 first
; /* first four bytes of data and padding */
163 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
170 check
= ntohl(sp
->hdr
.seq
^ sp
->hdr
.callNumber
);
171 data_size
|= (u32
) check
<< 16;
173 tmpbuf
.hdr
.data_size
= htonl(data_size
);
174 memcpy(&tmpbuf
.first
, sechdr
+ 4, sizeof(tmpbuf
.first
));
176 /* start the encryption afresh */
177 memset(&iv
, 0, sizeof(iv
));
178 desc
.tfm
= call
->conn
->cipher
;
182 memset(sg
, 0, sizeof(sg
));
183 sg_set_buf(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
184 sg_set_buf(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
185 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
187 memcpy(sechdr
, &tmpbuf
, sizeof(tmpbuf
));
194 * wholly encrypt a packet (level 2 security)
196 static int rxkad_secure_packet_encrypt(const struct rxrpc_call
*call
,
201 const struct rxrpc_key_payload
*payload
;
202 struct rxkad_level2_hdr rxkhdr
203 __attribute__((aligned(8))); /* must be all on one page */
204 struct rxrpc_skb_priv
*sp
;
205 struct blkcipher_desc desc
;
206 struct rxrpc_crypt iv
;
207 struct scatterlist sg
[16];
208 struct sk_buff
*trailer
;
217 check
= ntohl(sp
->hdr
.seq
^ sp
->hdr
.callNumber
);
219 rxkhdr
.data_size
= htonl(data_size
| (u32
) check
<< 16);
222 /* encrypt from the session key */
223 payload
= call
->conn
->key
->payload
.data
;
224 memcpy(&iv
, payload
->k
.session_key
, sizeof(iv
));
225 desc
.tfm
= call
->conn
->cipher
;
229 memset(sg
, 0, sizeof(sg
[0]) * 2);
230 sg_set_buf(&sg
[0], sechdr
, sizeof(rxkhdr
));
231 sg_set_buf(&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 skb_to_sgvec(skb
, sg
, 0, len
);
243 crypto_blkcipher_encrypt_iv(&desc
, sg
, sg
, len
);
250 * checksum an RxRPC packet header
252 static int rxkad_secure_packet(const struct rxrpc_call
*call
,
257 struct rxrpc_skb_priv
*sp
;
258 struct blkcipher_desc desc
;
259 struct rxrpc_crypt iv
;
260 struct scatterlist sg
[2];
263 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
269 _enter("{%d{%x}},{#%u},%zu,",
270 call
->debug_id
, key_serial(call
->conn
->key
), ntohl(sp
->hdr
.seq
),
273 if (!call
->conn
->cipher
)
276 ret
= key_validate(call
->conn
->key
);
280 /* continue encrypting from where we left off */
281 memcpy(&iv
, call
->conn
->csum_iv
.x
, sizeof(iv
));
282 desc
.tfm
= call
->conn
->cipher
;
286 /* calculate the security checksum */
287 x
= htonl(call
->channel
<< (32 - RXRPC_CIDSHIFT
));
288 x
|= sp
->hdr
.seq
& __constant_cpu_to_be32(0x3fffffff);
289 tmpbuf
.x
[0] = sp
->hdr
.callNumber
;
292 memset(&sg
, 0, sizeof(sg
));
293 sg_set_buf(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
294 sg_set_buf(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
295 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
297 x
= ntohl(tmpbuf
.x
[1]);
298 x
= (x
>> 16) & 0xffff;
300 x
= 1; /* zero checksums are not permitted */
301 sp
->hdr
.cksum
= htons(x
);
303 switch (call
->conn
->security_level
) {
304 case RXRPC_SECURITY_PLAIN
:
307 case RXRPC_SECURITY_AUTH
:
308 ret
= rxkad_secure_packet_auth(call
, skb
, data_size
, sechdr
);
310 case RXRPC_SECURITY_ENCRYPT
:
311 ret
= rxkad_secure_packet_encrypt(call
, skb
, data_size
,
319 _leave(" = %d [set %hx]", ret
, x
);
324 * decrypt partial encryption on a packet (level 1 security)
326 static int rxkad_verify_packet_auth(const struct rxrpc_call
*call
,
330 struct rxkad_level1_hdr sechdr
;
331 struct rxrpc_skb_priv
*sp
;
332 struct blkcipher_desc desc
;
333 struct rxrpc_crypt iv
;
334 struct scatterlist sg
[2];
335 struct sk_buff
*trailer
;
343 /* we want to decrypt the skbuff in-place */
344 if (skb_cow_data(skb
, 0, &trailer
) < 0)
347 skb_to_sgvec(skb
, sg
, 0, 8);
349 /* start the decryption afresh */
350 memset(&iv
, 0, sizeof(iv
));
351 desc
.tfm
= call
->conn
->cipher
;
355 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, 8);
357 /* remove the decrypted packet length */
358 if (skb_copy_bits(skb
, 0, &sechdr
, sizeof(sechdr
)) < 0)
360 if (!skb_pull(skb
, sizeof(sechdr
)))
363 buf
= ntohl(sechdr
.data_size
);
364 data_size
= buf
& 0xffff;
367 check
^= ntohl(sp
->hdr
.seq
^ sp
->hdr
.callNumber
);
370 *_abort_code
= RXKADSEALEDINCON
;
374 /* shorten the packet to remove the padding */
375 if (data_size
> skb
->len
)
377 else if (data_size
< skb
->len
)
378 skb
->len
= data_size
;
380 _leave(" = 0 [dlen=%x]", data_size
);
384 *_abort_code
= RXKADDATALEN
;
386 _leave(" = -EPROTO");
390 _leave(" = -ENOMEM");
395 * wholly decrypt a packet (level 2 security)
397 static int rxkad_verify_packet_encrypt(const struct rxrpc_call
*call
,
401 const struct rxrpc_key_payload
*payload
;
402 struct rxkad_level2_hdr sechdr
;
403 struct rxrpc_skb_priv
*sp
;
404 struct blkcipher_desc desc
;
405 struct rxrpc_crypt iv
;
406 struct scatterlist _sg
[4], *sg
;
407 struct sk_buff
*trailer
;
412 _enter(",{%d}", skb
->len
);
416 /* we want to decrypt the skbuff in-place */
417 nsg
= skb_cow_data(skb
, 0, &trailer
);
422 if (unlikely(nsg
> 4)) {
423 sg
= kmalloc(sizeof(*sg
) * nsg
, GFP_NOIO
);
428 skb_to_sgvec(skb
, sg
, 0, skb
->len
);
430 /* decrypt from the session key */
431 payload
= call
->conn
->key
->payload
.data
;
432 memcpy(&iv
, payload
->k
.session_key
, sizeof(iv
));
433 desc
.tfm
= call
->conn
->cipher
;
437 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, skb
->len
);
441 /* remove the decrypted packet length */
442 if (skb_copy_bits(skb
, 0, &sechdr
, sizeof(sechdr
)) < 0)
444 if (!skb_pull(skb
, sizeof(sechdr
)))
447 buf
= ntohl(sechdr
.data_size
);
448 data_size
= buf
& 0xffff;
451 check
^= ntohl(sp
->hdr
.seq
^ sp
->hdr
.callNumber
);
454 *_abort_code
= RXKADSEALEDINCON
;
458 /* shorten the packet to remove the padding */
459 if (data_size
> skb
->len
)
461 else if (data_size
< skb
->len
)
462 skb
->len
= data_size
;
464 _leave(" = 0 [dlen=%x]", data_size
);
468 *_abort_code
= RXKADDATALEN
;
470 _leave(" = -EPROTO");
474 _leave(" = -ENOMEM");
479 * verify the security on a received packet
481 static int rxkad_verify_packet(const struct rxrpc_call
*call
,
485 struct blkcipher_desc desc
;
486 struct rxrpc_skb_priv
*sp
;
487 struct rxrpc_crypt iv
;
488 struct scatterlist sg
[2];
491 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
498 _enter("{%d{%x}},{#%u}",
499 call
->debug_id
, key_serial(call
->conn
->key
),
502 if (!call
->conn
->cipher
)
505 if (sp
->hdr
.securityIndex
!= 2) {
506 *_abort_code
= RXKADINCONSISTENCY
;
507 _leave(" = -EPROTO [not rxkad]");
511 /* continue encrypting from where we left off */
512 memcpy(&iv
, call
->conn
->csum_iv
.x
, sizeof(iv
));
513 desc
.tfm
= call
->conn
->cipher
;
517 /* validate the security checksum */
518 x
= htonl(call
->channel
<< (32 - RXRPC_CIDSHIFT
));
519 x
|= sp
->hdr
.seq
& __constant_cpu_to_be32(0x3fffffff);
520 tmpbuf
.x
[0] = call
->call_id
;
523 memset(&sg
, 0, sizeof(sg
));
524 sg_set_buf(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
525 sg_set_buf(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
526 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
528 x
= ntohl(tmpbuf
.x
[1]);
529 x
= (x
>> 16) & 0xffff;
531 x
= 1; /* zero checksums are not permitted */
534 if (sp
->hdr
.cksum
!= cksum
) {
535 *_abort_code
= RXKADSEALEDINCON
;
536 _leave(" = -EPROTO [csum failed]");
540 switch (call
->conn
->security_level
) {
541 case RXRPC_SECURITY_PLAIN
:
544 case RXRPC_SECURITY_AUTH
:
545 ret
= rxkad_verify_packet_auth(call
, skb
, _abort_code
);
547 case RXRPC_SECURITY_ENCRYPT
:
548 ret
= rxkad_verify_packet_encrypt(call
, skb
, _abort_code
);
555 _leave(" = %d", ret
);
562 static int rxkad_issue_challenge(struct rxrpc_connection
*conn
)
564 struct rxkad_challenge challenge
;
565 struct rxrpc_header hdr
;
571 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->key
));
573 ret
= key_validate(conn
->key
);
577 get_random_bytes(&conn
->security_nonce
, sizeof(conn
->security_nonce
));
579 challenge
.version
= htonl(2);
580 challenge
.nonce
= htonl(conn
->security_nonce
);
581 challenge
.min_level
= htonl(0);
582 challenge
.__padding
= 0;
584 msg
.msg_name
= &conn
->trans
->peer
->srx
.transport
.sin
;
585 msg
.msg_namelen
= sizeof(conn
->trans
->peer
->srx
.transport
.sin
);
586 msg
.msg_control
= NULL
;
587 msg
.msg_controllen
= 0;
590 hdr
.epoch
= conn
->epoch
;
594 hdr
.type
= RXRPC_PACKET_TYPE_CHALLENGE
;
595 hdr
.flags
= conn
->out_clientflag
;
597 hdr
.securityIndex
= conn
->security_ix
;
599 hdr
.serviceId
= conn
->service_id
;
601 iov
[0].iov_base
= &hdr
;
602 iov
[0].iov_len
= sizeof(hdr
);
603 iov
[1].iov_base
= &challenge
;
604 iov
[1].iov_len
= sizeof(challenge
);
606 len
= iov
[0].iov_len
+ iov
[1].iov_len
;
608 hdr
.serial
= htonl(atomic_inc_return(&conn
->serial
));
609 _proto("Tx CHALLENGE %%%u", ntohl(hdr
.serial
));
611 ret
= kernel_sendmsg(conn
->trans
->local
->socket
, &msg
, iov
, 2, len
);
613 _debug("sendmsg failed: %d", ret
);
622 * send a Kerberos security response
624 static int rxkad_send_response(struct rxrpc_connection
*conn
,
625 struct rxrpc_header
*hdr
,
626 struct rxkad_response
*resp
,
627 const struct rxkad_key
*s2
)
636 msg
.msg_name
= &conn
->trans
->peer
->srx
.transport
.sin
;
637 msg
.msg_namelen
= sizeof(conn
->trans
->peer
->srx
.transport
.sin
);
638 msg
.msg_control
= NULL
;
639 msg
.msg_controllen
= 0;
642 hdr
->epoch
= conn
->epoch
;
644 hdr
->type
= RXRPC_PACKET_TYPE_RESPONSE
;
645 hdr
->flags
= conn
->out_clientflag
;
649 iov
[0].iov_base
= hdr
;
650 iov
[0].iov_len
= sizeof(*hdr
);
651 iov
[1].iov_base
= resp
;
652 iov
[1].iov_len
= sizeof(*resp
);
653 iov
[2].iov_base
= (void *) s2
->ticket
;
654 iov
[2].iov_len
= s2
->ticket_len
;
656 len
= iov
[0].iov_len
+ iov
[1].iov_len
+ iov
[2].iov_len
;
658 hdr
->serial
= htonl(atomic_inc_return(&conn
->serial
));
659 _proto("Tx RESPONSE %%%u", ntohl(hdr
->serial
));
661 ret
= kernel_sendmsg(conn
->trans
->local
->socket
, &msg
, iov
, 3, len
);
663 _debug("sendmsg failed: %d", ret
);
672 * calculate the response checksum
674 static void rxkad_calc_response_checksum(struct rxkad_response
*response
)
678 u8
*p
= (u8
*) response
;
680 for (loop
= sizeof(*response
); loop
> 0; loop
--)
681 csum
= csum
* 0x10204081 + *p
++;
683 response
->encrypted
.checksum
= htonl(csum
);
687 * load a scatterlist with a potentially split-page buffer
689 static void rxkad_sg_set_buf2(struct scatterlist sg
[2],
690 void *buf
, size_t buflen
)
693 memset(sg
, 0, sizeof(sg
));
695 sg_set_buf(&sg
[0], buf
, buflen
);
696 if (sg
[0].offset
+ buflen
> PAGE_SIZE
) {
697 /* the buffer was split over two pages */
698 sg
[0].length
= PAGE_SIZE
- sg
[0].offset
;
699 sg_set_buf(&sg
[1], buf
+ sg
[0].length
, buflen
- sg
[0].length
);
702 ASSERTCMP(sg
[0].length
+ sg
[1].length
, ==, buflen
);
706 * encrypt the response packet
708 static void rxkad_encrypt_response(struct rxrpc_connection
*conn
,
709 struct rxkad_response
*resp
,
710 const struct rxkad_key
*s2
)
712 struct blkcipher_desc desc
;
713 struct rxrpc_crypt iv
;
714 struct scatterlist ssg
[2], dsg
[2];
716 /* continue encrypting from where we left off */
717 memcpy(&iv
, s2
->session_key
, sizeof(iv
));
718 desc
.tfm
= conn
->cipher
;
722 rxkad_sg_set_buf2(ssg
, &resp
->encrypted
, sizeof(resp
->encrypted
));
723 memcpy(dsg
, ssg
, sizeof(dsg
));
724 crypto_blkcipher_encrypt_iv(&desc
, dsg
, ssg
, sizeof(resp
->encrypted
));
728 * respond to a challenge packet
730 static int rxkad_respond_to_challenge(struct rxrpc_connection
*conn
,
734 const struct rxrpc_key_payload
*payload
;
735 struct rxkad_challenge challenge
;
736 struct rxkad_response resp
737 __attribute__((aligned(8))); /* must be aligned for crypto */
738 struct rxrpc_skb_priv
*sp
;
739 u32 version
, nonce
, min_level
, abort_code
;
742 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->key
));
745 _leave(" = -EPROTO [no key]");
749 ret
= key_validate(conn
->key
);
751 *_abort_code
= RXKADEXPIRED
;
755 abort_code
= RXKADPACKETSHORT
;
757 if (skb_copy_bits(skb
, 0, &challenge
, sizeof(challenge
)) < 0)
760 version
= ntohl(challenge
.version
);
761 nonce
= ntohl(challenge
.nonce
);
762 min_level
= ntohl(challenge
.min_level
);
764 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
765 ntohl(sp
->hdr
.serial
), version
, nonce
, min_level
);
767 abort_code
= RXKADINCONSISTENCY
;
768 if (version
!= RXKAD_VERSION
)
771 abort_code
= RXKADLEVELFAIL
;
772 if (conn
->security_level
< min_level
)
775 payload
= conn
->key
->payload
.data
;
777 /* build the response packet */
778 memset(&resp
, 0, sizeof(resp
));
780 resp
.version
= RXKAD_VERSION
;
781 resp
.encrypted
.epoch
= conn
->epoch
;
782 resp
.encrypted
.cid
= conn
->cid
;
783 resp
.encrypted
.securityIndex
= htonl(conn
->security_ix
);
784 resp
.encrypted
.call_id
[0] =
785 (conn
->channels
[0] ? conn
->channels
[0]->call_id
: 0);
786 resp
.encrypted
.call_id
[1] =
787 (conn
->channels
[1] ? conn
->channels
[1]->call_id
: 0);
788 resp
.encrypted
.call_id
[2] =
789 (conn
->channels
[2] ? conn
->channels
[2]->call_id
: 0);
790 resp
.encrypted
.call_id
[3] =
791 (conn
->channels
[3] ? conn
->channels
[3]->call_id
: 0);
792 resp
.encrypted
.inc_nonce
= htonl(nonce
+ 1);
793 resp
.encrypted
.level
= htonl(conn
->security_level
);
794 resp
.kvno
= htonl(payload
->k
.kvno
);
795 resp
.ticket_len
= htonl(payload
->k
.ticket_len
);
797 /* calculate the response checksum and then do the encryption */
798 rxkad_calc_response_checksum(&resp
);
799 rxkad_encrypt_response(conn
, &resp
, &payload
->k
);
800 return rxkad_send_response(conn
, &sp
->hdr
, &resp
, &payload
->k
);
803 *_abort_code
= abort_code
;
804 _leave(" = -EPROTO [%d]", abort_code
);
809 * decrypt the kerberos IV ticket in the response
811 static int rxkad_decrypt_ticket(struct rxrpc_connection
*conn
,
812 void *ticket
, size_t ticket_len
,
813 struct rxrpc_crypt
*_session_key
,
817 struct blkcipher_desc desc
;
818 struct rxrpc_crypt iv
, key
;
819 struct scatterlist ssg
[1], dsg
[1];
825 u8
*p
, *q
, *name
, *end
;
827 _enter("{%d},{%x}", conn
->debug_id
, key_serial(conn
->server_key
));
831 ret
= key_validate(conn
->server_key
);
835 *_abort_code
= RXKADEXPIRED
;
838 *_abort_code
= RXKADNOAUTH
;
843 ASSERT(conn
->server_key
->payload
.data
!= NULL
);
844 ASSERTCMP((unsigned long) ticket
& 7UL, ==, 0);
846 memcpy(&iv
, &conn
->server_key
->type_data
, sizeof(iv
));
848 desc
.tfm
= conn
->server_key
->payload
.data
;
852 sg_init_one(&ssg
[0], ticket
, ticket_len
);
853 memcpy(dsg
, ssg
, sizeof(dsg
));
854 crypto_blkcipher_decrypt_iv(&desc
, dsg
, ssg
, ticket_len
);
857 end
= p
+ ticket_len
;
862 q = memchr(p, 0, end - p); \
863 if (!q || q - p > (size)) \
872 /* extract the ticket flags */
873 _debug("KIV FLAGS: %x", *p
);
874 little_endian
= *p
& 1;
877 /* extract the authentication name */
879 _debug("KIV ANAME: %s", name
);
881 /* extract the principal's instance */
883 _debug("KIV INST : %s", name
);
885 /* extract the principal's authentication domain */
887 _debug("KIV REALM: %s", name
);
889 if (end
- p
< 4 + 8 + 4 + 2)
892 /* get the IPv4 address of the entity that requested the ticket */
893 memcpy(&addr
, p
, sizeof(addr
));
895 _debug("KIV ADDR : "NIPQUAD_FMT
, NIPQUAD(addr
));
897 /* get the session key from the ticket */
898 memcpy(&key
, p
, sizeof(key
));
900 _debug("KIV KEY : %08x %08x", ntohl(key
.n
[0]), ntohl(key
.n
[1]));
901 memcpy(_session_key
, &key
, sizeof(key
));
903 /* get the ticket's lifetime */
904 life
= *p
++ * 5 * 60;
905 _debug("KIV LIFE : %u", life
);
907 /* get the issue time of the ticket */
910 memcpy(&stamp
, p
, 4);
911 issue
= le32_to_cpu(stamp
);
914 memcpy(&stamp
, p
, 4);
915 issue
= be32_to_cpu(stamp
);
919 _debug("KIV ISSUE: %lx [%lx]", issue
, now
);
921 /* check the ticket is in date */
923 *_abort_code
= RXKADNOAUTH
;
928 if (issue
< now
- life
) {
929 *_abort_code
= RXKADEXPIRED
;
934 *_expiry
= issue
+ life
;
936 /* get the service name */
938 _debug("KIV SNAME: %s", name
);
940 /* get the service instance name */
942 _debug("KIV SINST: %s", name
);
946 _leave(" = %d", ret
);
950 *_abort_code
= RXKADBADTICKET
;
956 * decrypt the response packet
958 static void rxkad_decrypt_response(struct rxrpc_connection
*conn
,
959 struct rxkad_response
*resp
,
960 const struct rxrpc_crypt
*session_key
)
962 struct blkcipher_desc desc
;
963 struct scatterlist ssg
[2], dsg
[2];
964 struct rxrpc_crypt iv
;
967 ntohl(session_key
->n
[0]), ntohl(session_key
->n
[1]));
969 ASSERT(rxkad_ci
!= NULL
);
971 mutex_lock(&rxkad_ci_mutex
);
972 if (crypto_blkcipher_setkey(rxkad_ci
, session_key
->x
,
973 sizeof(*session_key
)) < 0)
976 memcpy(&iv
, session_key
, sizeof(iv
));
981 rxkad_sg_set_buf2(ssg
, &resp
->encrypted
, sizeof(resp
->encrypted
));
982 memcpy(dsg
, ssg
, sizeof(dsg
));
983 crypto_blkcipher_decrypt_iv(&desc
, dsg
, ssg
, sizeof(resp
->encrypted
));
984 mutex_unlock(&rxkad_ci_mutex
);
992 static int rxkad_verify_response(struct rxrpc_connection
*conn
,
996 struct rxkad_response response
997 __attribute__((aligned(8))); /* must be aligned for crypto */
998 struct rxrpc_skb_priv
*sp
;
999 struct rxrpc_crypt session_key
;
1002 u32 abort_code
, version
, kvno
, ticket_len
, csum
, level
;
1005 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->server_key
));
1007 abort_code
= RXKADPACKETSHORT
;
1008 if (skb_copy_bits(skb
, 0, &response
, sizeof(response
)) < 0)
1009 goto protocol_error
;
1010 if (!pskb_pull(skb
, sizeof(response
)))
1013 version
= ntohl(response
.version
);
1014 ticket_len
= ntohl(response
.ticket_len
);
1015 kvno
= ntohl(response
.kvno
);
1016 sp
= rxrpc_skb(skb
);
1017 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1018 ntohl(sp
->hdr
.serial
), version
, kvno
, ticket_len
);
1020 abort_code
= RXKADINCONSISTENCY
;
1021 if (version
!= RXKAD_VERSION
)
1023 abort_code
= RXKADTICKETLEN
;
1024 if (ticket_len
< 4 || ticket_len
> MAXKRB5TICKETLEN
)
1025 goto protocol_error
;
1027 abort_code
= RXKADUNKNOWNKEY
;
1028 if (kvno
>= RXKAD_TKT_TYPE_KERBEROS_V5
)
1029 goto protocol_error
;
1031 /* extract the kerberos ticket and decrypt and decode it */
1032 ticket
= kmalloc(ticket_len
, GFP_NOFS
);
1036 abort_code
= RXKADPACKETSHORT
;
1037 if (skb_copy_bits(skb
, 0, ticket
, ticket_len
) < 0)
1038 goto protocol_error_free
;
1040 ret
= rxkad_decrypt_ticket(conn
, ticket
, ticket_len
, &session_key
,
1041 &expiry
, &abort_code
);
1043 *_abort_code
= abort_code
;
1048 /* use the session key from inside the ticket to decrypt the
1050 rxkad_decrypt_response(conn
, &response
, &session_key
);
1052 abort_code
= RXKADSEALEDINCON
;
1053 if (response
.encrypted
.epoch
!= conn
->epoch
)
1054 goto protocol_error_free
;
1055 if (response
.encrypted
.cid
!= conn
->cid
)
1056 goto protocol_error_free
;
1057 if (ntohl(response
.encrypted
.securityIndex
) != conn
->security_ix
)
1058 goto protocol_error_free
;
1059 csum
= response
.encrypted
.checksum
;
1060 response
.encrypted
.checksum
= 0;
1061 rxkad_calc_response_checksum(&response
);
1062 if (response
.encrypted
.checksum
!= csum
)
1063 goto protocol_error_free
;
1065 if (ntohl(response
.encrypted
.call_id
[0]) > INT_MAX
||
1066 ntohl(response
.encrypted
.call_id
[1]) > INT_MAX
||
1067 ntohl(response
.encrypted
.call_id
[2]) > INT_MAX
||
1068 ntohl(response
.encrypted
.call_id
[3]) > INT_MAX
)
1069 goto protocol_error_free
;
1071 abort_code
= RXKADOUTOFSEQUENCE
;
1072 if (response
.encrypted
.inc_nonce
!= htonl(conn
->security_nonce
+ 1))
1073 goto protocol_error_free
;
1075 abort_code
= RXKADLEVELFAIL
;
1076 level
= ntohl(response
.encrypted
.level
);
1077 if (level
> RXRPC_SECURITY_ENCRYPT
)
1078 goto protocol_error_free
;
1079 conn
->security_level
= level
;
1081 /* create a key to hold the security data and expiration time - after
1082 * this the connection security can be handled in exactly the same way
1083 * as for a client connection */
1084 ret
= rxrpc_get_server_data_key(conn
, &session_key
, expiry
, kvno
);
1094 protocol_error_free
:
1097 *_abort_code
= abort_code
;
1098 _leave(" = -EPROTO [%d]", abort_code
);
1103 * clear the connection security
1105 static void rxkad_clear(struct rxrpc_connection
*conn
)
1110 crypto_free_blkcipher(conn
->cipher
);
1114 * RxRPC Kerberos-based security
1116 static struct rxrpc_security rxkad
= {
1117 .owner
= THIS_MODULE
,
1119 .security_index
= RXKAD_VERSION
,
1120 .init_connection_security
= rxkad_init_connection_security
,
1121 .prime_packet_security
= rxkad_prime_packet_security
,
1122 .secure_packet
= rxkad_secure_packet
,
1123 .verify_packet
= rxkad_verify_packet
,
1124 .issue_challenge
= rxkad_issue_challenge
,
1125 .respond_to_challenge
= rxkad_respond_to_challenge
,
1126 .verify_response
= rxkad_verify_response
,
1127 .clear
= rxkad_clear
,
1130 static __init
int rxkad_init(void)
1134 /* pin the cipher we need so that the crypto layer doesn't invoke
1135 * keventd to go get it */
1136 rxkad_ci
= crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC
);
1137 if (IS_ERR(rxkad_ci
))
1138 return PTR_ERR(rxkad_ci
);
1140 return rxrpc_register_security(&rxkad
);
1143 module_init(rxkad_init
);
1145 static __exit
void rxkad_exit(void)
1149 rxrpc_unregister_security(&rxkad
);
1150 crypto_free_blkcipher(rxkad_ci
);
1153 module_exit(rxkad_exit
);