1 /* Kerberos-based RxRPC security
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/udp.h>
16 #include <linux/crypto.h>
17 #include <linux/scatterlist.h>
18 #include <linux/ctype.h>
19 #include <linux/slab.h>
21 #include <net/af_rxrpc.h>
22 #include <keys/rxrpc-type.h>
23 #define rxrpc_debug rxkad_debug
24 #include "ar-internal.h"
26 #define RXKAD_VERSION 2
27 #define MAXKRB5TICKETLEN 1024
28 #define RXKAD_TKT_TYPE_KERBEROS_V5 256
29 #define ANAME_SZ 40 /* size of authentication name */
30 #define INST_SZ 40 /* size of principal's instance */
31 #define REALM_SZ 40 /* size of principal's auth domain */
32 #define SNAME_SZ 40 /* size of service name */
34 unsigned int rxrpc_debug
;
35 module_param_named(debug
, rxrpc_debug
, uint
, S_IWUSR
| S_IRUGO
);
36 MODULE_PARM_DESC(debug
, "rxkad debugging mask");
38 struct rxkad_level1_hdr
{
39 __be32 data_size
; /* true data size (excluding padding) */
42 struct rxkad_level2_hdr
{
43 __be32 data_size
; /* true data size (excluding padding) */
44 __be32 checksum
; /* decrypted data checksum */
47 MODULE_DESCRIPTION("RxRPC network protocol type-2 security (Kerberos 4)");
48 MODULE_AUTHOR("Red Hat, Inc.");
49 MODULE_LICENSE("GPL");
52 * this holds a pinned cipher so that keventd doesn't get called by the cipher
53 * alloc routine, but since we have it to hand, we use it to decrypt RESPONSE
56 static struct crypto_blkcipher
*rxkad_ci
;
57 static DEFINE_MUTEX(rxkad_ci_mutex
);
60 * initialise connection security
62 static int rxkad_init_connection_security(struct rxrpc_connection
*conn
)
64 struct crypto_blkcipher
*ci
;
65 struct rxrpc_key_token
*token
;
68 _enter("{%d},{%x}", conn
->debug_id
, key_serial(conn
->key
));
70 token
= conn
->key
->payload
.data
[0];
71 conn
->security_ix
= token
->security_index
;
73 ci
= crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC
);
80 if (crypto_blkcipher_setkey(ci
, token
->kad
->session_key
,
81 sizeof(token
->kad
->session_key
)) < 0)
84 switch (conn
->security_level
) {
85 case RXRPC_SECURITY_PLAIN
:
87 case RXRPC_SECURITY_AUTH
:
89 conn
->security_size
= sizeof(struct rxkad_level1_hdr
);
90 conn
->header_size
+= sizeof(struct rxkad_level1_hdr
);
92 case RXRPC_SECURITY_ENCRYPT
:
94 conn
->security_size
= sizeof(struct rxkad_level2_hdr
);
95 conn
->header_size
+= sizeof(struct rxkad_level2_hdr
);
105 _leave(" = %d", ret
);
110 * prime the encryption state with the invariant parts of a connection's
113 static void rxkad_prime_packet_security(struct rxrpc_connection
*conn
)
115 struct rxrpc_key_token
*token
;
116 struct blkcipher_desc desc
;
117 struct scatterlist sg
[2];
118 struct rxrpc_crypt iv
;
121 } tmpbuf
__attribute__((aligned(16))); /* must all be in same page */
128 token
= conn
->key
->payload
.data
[0];
129 memcpy(&iv
, token
->kad
->session_key
, sizeof(iv
));
131 desc
.tfm
= conn
->cipher
;
135 tmpbuf
.x
[0] = htonl(conn
->epoch
);
136 tmpbuf
.x
[1] = htonl(conn
->cid
);
138 tmpbuf
.x
[3] = htonl(conn
->security_ix
);
140 sg_init_one(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
141 sg_init_one(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
142 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
144 memcpy(&conn
->csum_iv
, &tmpbuf
.x
[2], sizeof(conn
->csum_iv
));
145 ASSERTCMP(conn
->csum_iv
.n
[0], ==, tmpbuf
.x
[2]);
151 * partially encrypt a packet (level 1 security)
153 static int rxkad_secure_packet_auth(const struct rxrpc_call
*call
,
158 struct rxrpc_skb_priv
*sp
;
159 struct blkcipher_desc desc
;
160 struct rxrpc_crypt iv
;
161 struct scatterlist sg
[2];
163 struct rxkad_level1_hdr hdr
;
164 __be32 first
; /* first four bytes of data and padding */
165 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
172 check
= sp
->hdr
.seq
^ sp
->hdr
.callNumber
;
173 data_size
|= (u32
)check
<< 16;
175 tmpbuf
.hdr
.data_size
= htonl(data_size
);
176 memcpy(&tmpbuf
.first
, sechdr
+ 4, sizeof(tmpbuf
.first
));
178 /* start the encryption afresh */
179 memset(&iv
, 0, sizeof(iv
));
180 desc
.tfm
= call
->conn
->cipher
;
184 sg_init_one(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
185 sg_init_one(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
186 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
188 memcpy(sechdr
, &tmpbuf
, sizeof(tmpbuf
));
195 * wholly encrypt a packet (level 2 security)
197 static int rxkad_secure_packet_encrypt(const struct rxrpc_call
*call
,
202 const struct rxrpc_key_token
*token
;
203 struct rxkad_level2_hdr rxkhdr
204 __attribute__((aligned(8))); /* must be all on one page */
205 struct rxrpc_skb_priv
*sp
;
206 struct blkcipher_desc desc
;
207 struct rxrpc_crypt iv
;
208 struct scatterlist sg
[16];
209 struct sk_buff
*trailer
;
218 check
= sp
->hdr
.seq
^ sp
->hdr
.callNumber
;
220 rxkhdr
.data_size
= htonl(data_size
| (u32
)check
<< 16);
223 /* encrypt from the session key */
224 token
= call
->conn
->key
->payload
.data
[0];
225 memcpy(&iv
, token
->kad
->session_key
, sizeof(iv
));
226 desc
.tfm
= call
->conn
->cipher
;
230 sg_init_one(&sg
[0], sechdr
, sizeof(rxkhdr
));
231 sg_init_one(&sg
[1], &rxkhdr
, sizeof(rxkhdr
));
232 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(rxkhdr
));
234 /* we want to encrypt the skbuff in-place */
235 nsg
= skb_cow_data(skb
, 0, &trailer
);
236 if (nsg
< 0 || nsg
> 16)
239 len
= data_size
+ call
->conn
->size_align
- 1;
240 len
&= ~(call
->conn
->size_align
- 1);
242 sg_init_table(sg
, nsg
);
243 skb_to_sgvec(skb
, sg
, 0, len
);
244 crypto_blkcipher_encrypt_iv(&desc
, sg
, sg
, len
);
251 * checksum an RxRPC packet header
253 static int rxkad_secure_packet(const struct rxrpc_call
*call
,
258 struct rxrpc_skb_priv
*sp
;
259 struct blkcipher_desc desc
;
260 struct rxrpc_crypt iv
;
261 struct scatterlist sg
[2];
264 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
270 _enter("{%d{%x}},{#%u},%zu,",
271 call
->debug_id
, key_serial(call
->conn
->key
), sp
->hdr
.seq
,
274 if (!call
->conn
->cipher
)
277 ret
= key_validate(call
->conn
->key
);
281 /* continue encrypting from where we left off */
282 memcpy(&iv
, call
->conn
->csum_iv
.x
, sizeof(iv
));
283 desc
.tfm
= call
->conn
->cipher
;
287 /* calculate the security checksum */
288 x
= call
->channel
<< (32 - RXRPC_CIDSHIFT
);
289 x
|= sp
->hdr
.seq
& 0x3fffffff;
290 tmpbuf
.x
[0] = htonl(sp
->hdr
.callNumber
);
291 tmpbuf
.x
[1] = htonl(x
);
293 sg_init_one(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
294 sg_init_one(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
295 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
297 y
= ntohl(tmpbuf
.x
[1]);
298 y
= (y
>> 16) & 0xffff;
300 y
= 1; /* zero checksums are not permitted */
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
, y
);
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
[16];
335 struct sk_buff
*trailer
;
344 /* we want to decrypt the skbuff in-place */
345 nsg
= skb_cow_data(skb
, 0, &trailer
);
346 if (nsg
< 0 || nsg
> 16)
349 sg_init_table(sg
, nsg
);
350 skb_to_sgvec(skb
, sg
, 0, 8);
352 /* start the decryption afresh */
353 memset(&iv
, 0, sizeof(iv
));
354 desc
.tfm
= call
->conn
->cipher
;
358 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, 8);
360 /* remove the decrypted packet length */
361 if (skb_copy_bits(skb
, 0, &sechdr
, sizeof(sechdr
)) < 0)
363 if (!skb_pull(skb
, sizeof(sechdr
)))
366 buf
= ntohl(sechdr
.data_size
);
367 data_size
= buf
& 0xffff;
370 check
^= sp
->hdr
.seq
^ sp
->hdr
.callNumber
;
373 *_abort_code
= RXKADSEALEDINCON
;
377 /* shorten the packet to remove the padding */
378 if (data_size
> skb
->len
)
380 else if (data_size
< skb
->len
)
381 skb
->len
= data_size
;
383 _leave(" = 0 [dlen=%x]", data_size
);
387 *_abort_code
= RXKADDATALEN
;
389 _leave(" = -EPROTO");
393 _leave(" = -ENOMEM");
398 * wholly decrypt a packet (level 2 security)
400 static int rxkad_verify_packet_encrypt(const struct rxrpc_call
*call
,
404 const struct rxrpc_key_token
*token
;
405 struct rxkad_level2_hdr sechdr
;
406 struct rxrpc_skb_priv
*sp
;
407 struct blkcipher_desc desc
;
408 struct rxrpc_crypt iv
;
409 struct scatterlist _sg
[4], *sg
;
410 struct sk_buff
*trailer
;
415 _enter(",{%d}", skb
->len
);
419 /* we want to decrypt the skbuff in-place */
420 nsg
= skb_cow_data(skb
, 0, &trailer
);
425 if (unlikely(nsg
> 4)) {
426 sg
= kmalloc(sizeof(*sg
) * nsg
, GFP_NOIO
);
431 sg_init_table(sg
, nsg
);
432 skb_to_sgvec(skb
, sg
, 0, skb
->len
);
434 /* decrypt from the session key */
435 token
= call
->conn
->key
->payload
.data
[0];
436 memcpy(&iv
, token
->kad
->session_key
, sizeof(iv
));
437 desc
.tfm
= call
->conn
->cipher
;
441 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, skb
->len
);
445 /* remove the decrypted packet length */
446 if (skb_copy_bits(skb
, 0, &sechdr
, sizeof(sechdr
)) < 0)
448 if (!skb_pull(skb
, sizeof(sechdr
)))
451 buf
= ntohl(sechdr
.data_size
);
452 data_size
= buf
& 0xffff;
455 check
^= sp
->hdr
.seq
^ sp
->hdr
.callNumber
;
458 *_abort_code
= RXKADSEALEDINCON
;
462 /* shorten the packet to remove the padding */
463 if (data_size
> skb
->len
)
465 else if (data_size
< skb
->len
)
466 skb
->len
= data_size
;
468 _leave(" = 0 [dlen=%x]", data_size
);
472 *_abort_code
= RXKADDATALEN
;
474 _leave(" = -EPROTO");
478 _leave(" = -ENOMEM");
483 * verify the security on a received packet
485 static int rxkad_verify_packet(const struct rxrpc_call
*call
,
489 struct blkcipher_desc desc
;
490 struct rxrpc_skb_priv
*sp
;
491 struct rxrpc_crypt iv
;
492 struct scatterlist sg
[2];
495 } tmpbuf
__attribute__((aligned(8))); /* must all be in same page */
502 _enter("{%d{%x}},{#%u}",
503 call
->debug_id
, key_serial(call
->conn
->key
), sp
->hdr
.seq
);
505 if (!call
->conn
->cipher
)
508 if (sp
->hdr
.securityIndex
!= RXRPC_SECURITY_RXKAD
) {
509 *_abort_code
= RXKADINCONSISTENCY
;
510 _leave(" = -EPROTO [not rxkad]");
514 /* continue encrypting from where we left off */
515 memcpy(&iv
, call
->conn
->csum_iv
.x
, sizeof(iv
));
516 desc
.tfm
= call
->conn
->cipher
;
520 /* validate the security checksum */
521 x
= call
->channel
<< (32 - RXRPC_CIDSHIFT
);
522 x
|= sp
->hdr
.seq
& 0x3fffffff;
523 tmpbuf
.x
[0] = htonl(call
->call_id
);
524 tmpbuf
.x
[1] = htonl(x
);
526 sg_init_one(&sg
[0], &tmpbuf
, sizeof(tmpbuf
));
527 sg_init_one(&sg
[1], &tmpbuf
, sizeof(tmpbuf
));
528 crypto_blkcipher_encrypt_iv(&desc
, &sg
[0], &sg
[1], sizeof(tmpbuf
));
530 y
= ntohl(tmpbuf
.x
[1]);
531 cksum
= (y
>> 16) & 0xffff;
533 cksum
= 1; /* zero checksums are not permitted */
535 if (sp
->hdr
.cksum
!= cksum
) {
536 *_abort_code
= RXKADSEALEDINCON
;
537 _leave(" = -EPROTO [csum failed]");
541 switch (call
->conn
->security_level
) {
542 case RXRPC_SECURITY_PLAIN
:
545 case RXRPC_SECURITY_AUTH
:
546 ret
= rxkad_verify_packet_auth(call
, skb
, _abort_code
);
548 case RXRPC_SECURITY_ENCRYPT
:
549 ret
= rxkad_verify_packet_encrypt(call
, skb
, _abort_code
);
556 _leave(" = %d", ret
);
563 static int rxkad_issue_challenge(struct rxrpc_connection
*conn
)
565 struct rxkad_challenge challenge
;
566 struct rxrpc_wire_header whdr
;
573 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->key
));
575 ret
= key_validate(conn
->key
);
579 get_random_bytes(&conn
->security_nonce
, sizeof(conn
->security_nonce
));
581 challenge
.version
= htonl(2);
582 challenge
.nonce
= htonl(conn
->security_nonce
);
583 challenge
.min_level
= htonl(0);
584 challenge
.__padding
= 0;
586 msg
.msg_name
= &conn
->trans
->peer
->srx
.transport
.sin
;
587 msg
.msg_namelen
= sizeof(conn
->trans
->peer
->srx
.transport
.sin
);
588 msg
.msg_control
= NULL
;
589 msg
.msg_controllen
= 0;
592 whdr
.epoch
= htonl(conn
->epoch
);
593 whdr
.cid
= htonl(conn
->cid
);
596 whdr
.type
= RXRPC_PACKET_TYPE_CHALLENGE
;
597 whdr
.flags
= conn
->out_clientflag
;
599 whdr
.securityIndex
= conn
->security_ix
;
601 whdr
.serviceId
= htons(conn
->service_id
);
603 iov
[0].iov_base
= &whdr
;
604 iov
[0].iov_len
= sizeof(whdr
);
605 iov
[1].iov_base
= &challenge
;
606 iov
[1].iov_len
= sizeof(challenge
);
608 len
= iov
[0].iov_len
+ iov
[1].iov_len
;
610 serial
= atomic_inc_return(&conn
->serial
);
611 whdr
.serial
= htonl(serial
);
612 _proto("Tx CHALLENGE %%%u", serial
);
614 ret
= kernel_sendmsg(conn
->trans
->local
->socket
, &msg
, iov
, 2, len
);
616 _debug("sendmsg failed: %d", ret
);
625 * send a Kerberos security response
627 static int rxkad_send_response(struct rxrpc_connection
*conn
,
628 struct rxrpc_host_header
*hdr
,
629 struct rxkad_response
*resp
,
630 const struct rxkad_key
*s2
)
632 struct rxrpc_wire_header whdr
;
641 msg
.msg_name
= &conn
->trans
->peer
->srx
.transport
.sin
;
642 msg
.msg_namelen
= sizeof(conn
->trans
->peer
->srx
.transport
.sin
);
643 msg
.msg_control
= NULL
;
644 msg
.msg_controllen
= 0;
647 memset(&whdr
, 0, sizeof(whdr
));
648 whdr
.epoch
= htonl(hdr
->epoch
);
649 whdr
.cid
= htonl(hdr
->cid
);
650 whdr
.type
= RXRPC_PACKET_TYPE_RESPONSE
;
651 whdr
.flags
= conn
->out_clientflag
;
652 whdr
.securityIndex
= hdr
->securityIndex
;
653 whdr
.serviceId
= htons(hdr
->serviceId
);
655 iov
[0].iov_base
= &whdr
;
656 iov
[0].iov_len
= sizeof(whdr
);
657 iov
[1].iov_base
= resp
;
658 iov
[1].iov_len
= sizeof(*resp
);
659 iov
[2].iov_base
= (void *)s2
->ticket
;
660 iov
[2].iov_len
= s2
->ticket_len
;
662 len
= iov
[0].iov_len
+ iov
[1].iov_len
+ iov
[2].iov_len
;
664 serial
= atomic_inc_return(&conn
->serial
);
665 whdr
.serial
= htonl(serial
);
666 _proto("Tx RESPONSE %%%u", serial
);
668 ret
= kernel_sendmsg(conn
->trans
->local
->socket
, &msg
, iov
, 3, len
);
670 _debug("sendmsg failed: %d", ret
);
679 * calculate the response checksum
681 static void rxkad_calc_response_checksum(struct rxkad_response
*response
)
685 u8
*p
= (u8
*) response
;
687 for (loop
= sizeof(*response
); loop
> 0; loop
--)
688 csum
= csum
* 0x10204081 + *p
++;
690 response
->encrypted
.checksum
= htonl(csum
);
694 * load a scatterlist with a potentially split-page buffer
696 static void rxkad_sg_set_buf2(struct scatterlist sg
[2],
697 void *buf
, size_t buflen
)
701 sg_init_table(sg
, 2);
703 sg_set_buf(&sg
[0], buf
, buflen
);
704 if (sg
[0].offset
+ buflen
> PAGE_SIZE
) {
705 /* the buffer was split over two pages */
706 sg
[0].length
= PAGE_SIZE
- sg
[0].offset
;
707 sg_set_buf(&sg
[1], buf
+ sg
[0].length
, buflen
- sg
[0].length
);
711 sg_mark_end(&sg
[nsg
- 1]);
713 ASSERTCMP(sg
[0].length
+ sg
[1].length
, ==, buflen
);
717 * encrypt the response packet
719 static void rxkad_encrypt_response(struct rxrpc_connection
*conn
,
720 struct rxkad_response
*resp
,
721 const struct rxkad_key
*s2
)
723 struct blkcipher_desc desc
;
724 struct rxrpc_crypt iv
;
725 struct scatterlist sg
[2];
727 /* continue encrypting from where we left off */
728 memcpy(&iv
, s2
->session_key
, sizeof(iv
));
729 desc
.tfm
= conn
->cipher
;
733 rxkad_sg_set_buf2(sg
, &resp
->encrypted
, sizeof(resp
->encrypted
));
734 crypto_blkcipher_encrypt_iv(&desc
, sg
, sg
, sizeof(resp
->encrypted
));
738 * respond to a challenge packet
740 static int rxkad_respond_to_challenge(struct rxrpc_connection
*conn
,
744 const struct rxrpc_key_token
*token
;
745 struct rxkad_challenge challenge
;
746 struct rxkad_response resp
747 __attribute__((aligned(8))); /* must be aligned for crypto */
748 struct rxrpc_skb_priv
*sp
;
749 u32 version
, nonce
, min_level
, abort_code
;
752 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->key
));
755 _leave(" = -EPROTO [no key]");
759 ret
= key_validate(conn
->key
);
761 *_abort_code
= RXKADEXPIRED
;
765 abort_code
= RXKADPACKETSHORT
;
767 if (skb_copy_bits(skb
, 0, &challenge
, sizeof(challenge
)) < 0)
770 version
= ntohl(challenge
.version
);
771 nonce
= ntohl(challenge
.nonce
);
772 min_level
= ntohl(challenge
.min_level
);
774 _proto("Rx CHALLENGE %%%u { v=%u n=%u ml=%u }",
775 sp
->hdr
.serial
, version
, nonce
, min_level
);
777 abort_code
= RXKADINCONSISTENCY
;
778 if (version
!= RXKAD_VERSION
)
781 abort_code
= RXKADLEVELFAIL
;
782 if (conn
->security_level
< min_level
)
785 token
= conn
->key
->payload
.data
[0];
787 /* build the response packet */
788 memset(&resp
, 0, sizeof(resp
));
790 resp
.version
= htonl(RXKAD_VERSION
);
791 resp
.encrypted
.epoch
= htonl(conn
->epoch
);
792 resp
.encrypted
.cid
= htonl(conn
->cid
);
793 resp
.encrypted
.securityIndex
= htonl(conn
->security_ix
);
794 resp
.encrypted
.inc_nonce
= htonl(nonce
+ 1);
795 resp
.encrypted
.level
= htonl(conn
->security_level
);
796 resp
.kvno
= htonl(token
->kad
->kvno
);
797 resp
.ticket_len
= htonl(token
->kad
->ticket_len
);
799 resp
.encrypted
.call_id
[0] =
800 htonl(conn
->channels
[0] ? conn
->channels
[0]->call_id
: 0);
801 resp
.encrypted
.call_id
[1] =
802 htonl(conn
->channels
[1] ? conn
->channels
[1]->call_id
: 0);
803 resp
.encrypted
.call_id
[2] =
804 htonl(conn
->channels
[2] ? conn
->channels
[2]->call_id
: 0);
805 resp
.encrypted
.call_id
[3] =
806 htonl(conn
->channels
[3] ? conn
->channels
[3]->call_id
: 0);
808 /* calculate the response checksum and then do the encryption */
809 rxkad_calc_response_checksum(&resp
);
810 rxkad_encrypt_response(conn
, &resp
, token
->kad
);
811 return rxkad_send_response(conn
, &sp
->hdr
, &resp
, token
->kad
);
814 *_abort_code
= abort_code
;
815 _leave(" = -EPROTO [%d]", abort_code
);
820 * decrypt the kerberos IV ticket in the response
822 static int rxkad_decrypt_ticket(struct rxrpc_connection
*conn
,
823 void *ticket
, size_t ticket_len
,
824 struct rxrpc_crypt
*_session_key
,
828 struct blkcipher_desc desc
;
829 struct rxrpc_crypt iv
, key
;
830 struct scatterlist sg
[1];
836 u8
*p
, *q
, *name
, *end
;
838 _enter("{%d},{%x}", conn
->debug_id
, key_serial(conn
->server_key
));
842 ret
= key_validate(conn
->server_key
);
846 *_abort_code
= RXKADEXPIRED
;
849 *_abort_code
= RXKADNOAUTH
;
854 ASSERT(conn
->server_key
->payload
.data
[0] != NULL
);
855 ASSERTCMP((unsigned long) ticket
& 7UL, ==, 0);
857 memcpy(&iv
, &conn
->server_key
->payload
.data
[2], sizeof(iv
));
859 desc
.tfm
= conn
->server_key
->payload
.data
[0];
863 sg_init_one(&sg
[0], ticket
, ticket_len
);
864 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, ticket_len
);
867 end
= p
+ ticket_len
;
872 q = memchr(p, 0, end - p); \
873 if (!q || q - p > (size)) \
882 /* extract the ticket flags */
883 _debug("KIV FLAGS: %x", *p
);
884 little_endian
= *p
& 1;
887 /* extract the authentication name */
889 _debug("KIV ANAME: %s", name
);
891 /* extract the principal's instance */
893 _debug("KIV INST : %s", name
);
895 /* extract the principal's authentication domain */
897 _debug("KIV REALM: %s", name
);
899 if (end
- p
< 4 + 8 + 4 + 2)
902 /* get the IPv4 address of the entity that requested the ticket */
903 memcpy(&addr
, p
, sizeof(addr
));
905 _debug("KIV ADDR : %pI4", &addr
);
907 /* get the session key from the ticket */
908 memcpy(&key
, p
, sizeof(key
));
910 _debug("KIV KEY : %08x %08x", ntohl(key
.n
[0]), ntohl(key
.n
[1]));
911 memcpy(_session_key
, &key
, sizeof(key
));
913 /* get the ticket's lifetime */
914 life
= *p
++ * 5 * 60;
915 _debug("KIV LIFE : %u", life
);
917 /* get the issue time of the ticket */
920 memcpy(&stamp
, p
, 4);
921 issue
= le32_to_cpu(stamp
);
924 memcpy(&stamp
, p
, 4);
925 issue
= be32_to_cpu(stamp
);
929 _debug("KIV ISSUE: %lx [%lx]", issue
, now
);
931 /* check the ticket is in date */
933 *_abort_code
= RXKADNOAUTH
;
938 if (issue
< now
- life
) {
939 *_abort_code
= RXKADEXPIRED
;
944 *_expiry
= issue
+ life
;
946 /* get the service name */
948 _debug("KIV SNAME: %s", name
);
950 /* get the service instance name */
952 _debug("KIV SINST: %s", name
);
956 _leave(" = %d", ret
);
960 *_abort_code
= RXKADBADTICKET
;
966 * decrypt the response packet
968 static void rxkad_decrypt_response(struct rxrpc_connection
*conn
,
969 struct rxkad_response
*resp
,
970 const struct rxrpc_crypt
*session_key
)
972 struct blkcipher_desc desc
;
973 struct scatterlist sg
[2];
974 struct rxrpc_crypt iv
;
977 ntohl(session_key
->n
[0]), ntohl(session_key
->n
[1]));
979 ASSERT(rxkad_ci
!= NULL
);
981 mutex_lock(&rxkad_ci_mutex
);
982 if (crypto_blkcipher_setkey(rxkad_ci
, session_key
->x
,
983 sizeof(*session_key
)) < 0)
986 memcpy(&iv
, session_key
, sizeof(iv
));
991 rxkad_sg_set_buf2(sg
, &resp
->encrypted
, sizeof(resp
->encrypted
));
992 crypto_blkcipher_decrypt_iv(&desc
, sg
, sg
, sizeof(resp
->encrypted
));
993 mutex_unlock(&rxkad_ci_mutex
);
1001 static int rxkad_verify_response(struct rxrpc_connection
*conn
,
1002 struct sk_buff
*skb
,
1005 struct rxkad_response response
1006 __attribute__((aligned(8))); /* must be aligned for crypto */
1007 struct rxrpc_skb_priv
*sp
;
1008 struct rxrpc_crypt session_key
;
1011 u32 abort_code
, version
, kvno
, ticket_len
, level
;
1015 _enter("{%d,%x}", conn
->debug_id
, key_serial(conn
->server_key
));
1017 abort_code
= RXKADPACKETSHORT
;
1018 if (skb_copy_bits(skb
, 0, &response
, sizeof(response
)) < 0)
1019 goto protocol_error
;
1020 if (!pskb_pull(skb
, sizeof(response
)))
1023 version
= ntohl(response
.version
);
1024 ticket_len
= ntohl(response
.ticket_len
);
1025 kvno
= ntohl(response
.kvno
);
1026 sp
= rxrpc_skb(skb
);
1027 _proto("Rx RESPONSE %%%u { v=%u kv=%u tl=%u }",
1028 sp
->hdr
.serial
, version
, kvno
, ticket_len
);
1030 abort_code
= RXKADINCONSISTENCY
;
1031 if (version
!= RXKAD_VERSION
)
1032 goto protocol_error
;
1034 abort_code
= RXKADTICKETLEN
;
1035 if (ticket_len
< 4 || ticket_len
> MAXKRB5TICKETLEN
)
1036 goto protocol_error
;
1038 abort_code
= RXKADUNKNOWNKEY
;
1039 if (kvno
>= RXKAD_TKT_TYPE_KERBEROS_V5
)
1040 goto protocol_error
;
1042 /* extract the kerberos ticket and decrypt and decode it */
1043 ticket
= kmalloc(ticket_len
, GFP_NOFS
);
1047 abort_code
= RXKADPACKETSHORT
;
1048 if (skb_copy_bits(skb
, 0, ticket
, ticket_len
) < 0)
1049 goto protocol_error_free
;
1051 ret
= rxkad_decrypt_ticket(conn
, ticket
, ticket_len
, &session_key
,
1052 &expiry
, &abort_code
);
1054 *_abort_code
= abort_code
;
1059 /* use the session key from inside the ticket to decrypt the
1061 rxkad_decrypt_response(conn
, &response
, &session_key
);
1063 abort_code
= RXKADSEALEDINCON
;
1064 if (ntohl(response
.encrypted
.epoch
) != conn
->epoch
)
1065 goto protocol_error_free
;
1066 if (ntohl(response
.encrypted
.cid
) != conn
->cid
)
1067 goto protocol_error_free
;
1068 if (ntohl(response
.encrypted
.securityIndex
) != conn
->security_ix
)
1069 goto protocol_error_free
;
1070 csum
= response
.encrypted
.checksum
;
1071 response
.encrypted
.checksum
= 0;
1072 rxkad_calc_response_checksum(&response
);
1073 if (response
.encrypted
.checksum
!= csum
)
1074 goto protocol_error_free
;
1076 if (ntohl(response
.encrypted
.call_id
[0]) > INT_MAX
||
1077 ntohl(response
.encrypted
.call_id
[1]) > INT_MAX
||
1078 ntohl(response
.encrypted
.call_id
[2]) > INT_MAX
||
1079 ntohl(response
.encrypted
.call_id
[3]) > INT_MAX
)
1080 goto protocol_error_free
;
1082 abort_code
= RXKADOUTOFSEQUENCE
;
1083 if (ntohl(response
.encrypted
.inc_nonce
) != conn
->security_nonce
+ 1)
1084 goto protocol_error_free
;
1086 abort_code
= RXKADLEVELFAIL
;
1087 level
= ntohl(response
.encrypted
.level
);
1088 if (level
> RXRPC_SECURITY_ENCRYPT
)
1089 goto protocol_error_free
;
1090 conn
->security_level
= level
;
1092 /* create a key to hold the security data and expiration time - after
1093 * this the connection security can be handled in exactly the same way
1094 * as for a client connection */
1095 ret
= rxrpc_get_server_data_key(conn
, &session_key
, expiry
, kvno
);
1105 protocol_error_free
:
1108 *_abort_code
= abort_code
;
1109 _leave(" = -EPROTO [%d]", abort_code
);
1114 * clear the connection security
1116 static void rxkad_clear(struct rxrpc_connection
*conn
)
1121 crypto_free_blkcipher(conn
->cipher
);
1125 * RxRPC Kerberos-based security
1127 static struct rxrpc_security rxkad
= {
1128 .owner
= THIS_MODULE
,
1130 .security_index
= RXRPC_SECURITY_RXKAD
,
1131 .init_connection_security
= rxkad_init_connection_security
,
1132 .prime_packet_security
= rxkad_prime_packet_security
,
1133 .secure_packet
= rxkad_secure_packet
,
1134 .verify_packet
= rxkad_verify_packet
,
1135 .issue_challenge
= rxkad_issue_challenge
,
1136 .respond_to_challenge
= rxkad_respond_to_challenge
,
1137 .verify_response
= rxkad_verify_response
,
1138 .clear
= rxkad_clear
,
1141 static __init
int rxkad_init(void)
1145 /* pin the cipher we need so that the crypto layer doesn't invoke
1146 * keventd to go get it */
1147 rxkad_ci
= crypto_alloc_blkcipher("pcbc(fcrypt)", 0, CRYPTO_ALG_ASYNC
);
1148 if (IS_ERR(rxkad_ci
))
1149 return PTR_ERR(rxkad_ci
);
1151 return rxrpc_register_security(&rxkad
);
1154 module_init(rxkad_init
);
1156 static __exit
void rxkad_exit(void)
1160 rxrpc_unregister_security(&rxkad
);
1161 crypto_free_blkcipher(rxkad_ci
);
1164 module_exit(rxkad_exit
);