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-rw-r--r--fs/ecryptfs/keystore.c1078
1 files changed, 611 insertions, 467 deletions
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index b550dea8eee6..89d9710dd63d 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -39,7 +39,7 @@
39 * determine the type of error, make appropriate log entries, and 39 * determine the type of error, make appropriate log entries, and
40 * return an error code. 40 * return an error code.
41 */ 41 */
42int process_request_key_err(long err_code) 42static int process_request_key_err(long err_code)
43{ 43{
44 int rc = 0; 44 int rc = 0;
45 45
@@ -71,7 +71,7 @@ int process_request_key_err(long err_code)
71 * address; zero on error 71 * address; zero on error
72 * @length_size: The number of bytes occupied by the encoded length 72 * @length_size: The number of bytes occupied by the encoded length
73 * 73 *
74 * Returns Zero on success 74 * Returns zero on success; non-zero on error
75 */ 75 */
76static int parse_packet_length(unsigned char *data, size_t *size, 76static int parse_packet_length(unsigned char *data, size_t *size,
77 size_t *length_size) 77 size_t *length_size)
@@ -106,11 +106,11 @@ out:
106 106
107/** 107/**
108 * write_packet_length 108 * write_packet_length
109 * @dest: The byte array target into which to write the 109 * @dest: The byte array target into which to write the length. Must
110 * length. Must have at least 5 bytes allocated. 110 * have at least 5 bytes allocated.
111 * @size: The length to write. 111 * @size: The length to write.
112 * @packet_size_length: The number of bytes used to encode the 112 * @packet_size_length: The number of bytes used to encode the packet
113 * packet length is written to this address. 113 * length is written to this address.
114 * 114 *
115 * Returns zero on success; non-zero on error. 115 * Returns zero on success; non-zero on error.
116 */ 116 */
@@ -396,26 +396,53 @@ out:
396 return rc; 396 return rc;
397} 397}
398 398
399static int
400ecryptfs_get_auth_tok_sig(char **sig, struct ecryptfs_auth_tok *auth_tok)
401{
402 int rc = 0;
403
404 (*sig) = NULL;
405 switch (auth_tok->token_type) {
406 case ECRYPTFS_PASSWORD:
407 (*sig) = auth_tok->token.password.signature;
408 break;
409 case ECRYPTFS_PRIVATE_KEY:
410 (*sig) = auth_tok->token.private_key.signature;
411 break;
412 default:
413 printk(KERN_ERR "Cannot get sig for auth_tok of type [%d]\n",
414 auth_tok->token_type);
415 rc = -EINVAL;
416 }
417 return rc;
418}
419
399/** 420/**
400 * decrypt_pki_encrypted_session_key - Decrypt the session key with 421 * decrypt_pki_encrypted_session_key - Decrypt the session key with the given auth_tok.
401 * the given auth_tok. 422 * @auth_tok: The key authentication token used to decrypt the session key
423 * @crypt_stat: The cryptographic context
402 * 424 *
403 * Returns Zero on success; non-zero error otherwise. 425 * Returns zero on success; non-zero error otherwise.
404 */ 426 */
405static int decrypt_pki_encrypted_session_key( 427static int
406 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, 428decrypt_pki_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
407 struct ecryptfs_auth_tok *auth_tok, 429 struct ecryptfs_crypt_stat *crypt_stat)
408 struct ecryptfs_crypt_stat *crypt_stat)
409{ 430{
410 u16 cipher_code = 0; 431 u16 cipher_code = 0;
411 struct ecryptfs_msg_ctx *msg_ctx; 432 struct ecryptfs_msg_ctx *msg_ctx;
412 struct ecryptfs_message *msg = NULL; 433 struct ecryptfs_message *msg = NULL;
434 char *auth_tok_sig;
413 char *netlink_message; 435 char *netlink_message;
414 size_t netlink_message_length; 436 size_t netlink_message_length;
415 int rc; 437 int rc;
416 438
417 rc = write_tag_64_packet(mount_crypt_stat->global_auth_tok_sig, 439 rc = ecryptfs_get_auth_tok_sig(&auth_tok_sig, auth_tok);
418 &(auth_tok->session_key), 440 if (rc) {
441 printk(KERN_ERR "Unrecognized auth tok type: [%d]\n",
442 auth_tok->token_type);
443 goto out;
444 }
445 rc = write_tag_64_packet(auth_tok_sig, &(auth_tok->session_key),
419 &netlink_message, &netlink_message_length); 446 &netlink_message, &netlink_message_length);
420 if (rc) { 447 if (rc) {
421 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet"); 448 ecryptfs_printk(KERN_ERR, "Failed to write tag 64 packet");
@@ -465,40 +492,33 @@ out:
465 492
466static void wipe_auth_tok_list(struct list_head *auth_tok_list_head) 493static void wipe_auth_tok_list(struct list_head *auth_tok_list_head)
467{ 494{
468 struct list_head *walker;
469 struct ecryptfs_auth_tok_list_item *auth_tok_list_item; 495 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
496 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
470 497
471 walker = auth_tok_list_head->next; 498 list_for_each_entry_safe(auth_tok_list_item, auth_tok_list_item_tmp,
472 while (walker != auth_tok_list_head) { 499 auth_tok_list_head, list) {
473 auth_tok_list_item = 500 list_del(&auth_tok_list_item->list);
474 list_entry(walker, struct ecryptfs_auth_tok_list_item,
475 list);
476 walker = auth_tok_list_item->list.next;
477 memset(auth_tok_list_item, 0,
478 sizeof(struct ecryptfs_auth_tok_list_item));
479 kmem_cache_free(ecryptfs_auth_tok_list_item_cache, 501 kmem_cache_free(ecryptfs_auth_tok_list_item_cache,
480 auth_tok_list_item); 502 auth_tok_list_item);
481 } 503 }
482 auth_tok_list_head->next = NULL;
483} 504}
484 505
485struct kmem_cache *ecryptfs_auth_tok_list_item_cache; 506struct kmem_cache *ecryptfs_auth_tok_list_item_cache;
486 507
487
488/** 508/**
489 * parse_tag_1_packet 509 * parse_tag_1_packet
490 * @crypt_stat: The cryptographic context to modify based on packet 510 * @crypt_stat: The cryptographic context to modify based on packet contents
491 * contents.
492 * @data: The raw bytes of the packet. 511 * @data: The raw bytes of the packet.
493 * @auth_tok_list: eCryptfs parses packets into authentication tokens; 512 * @auth_tok_list: eCryptfs parses packets into authentication tokens;
494 * a new authentication token will be placed at the end 513 * a new authentication token will be placed at the
495 * of this list for this packet. 514 * end of this list for this packet.
496 * @new_auth_tok: Pointer to a pointer to memory that this function 515 * @new_auth_tok: Pointer to a pointer to memory that this function
497 * allocates; sets the memory address of the pointer to 516 * allocates; sets the memory address of the pointer to
498 * NULL on error. This object is added to the 517 * NULL on error. This object is added to the
499 * auth_tok_list. 518 * auth_tok_list.
500 * @packet_size: This function writes the size of the parsed packet 519 * @packet_size: This function writes the size of the parsed packet
501 * into this memory location; zero on error. 520 * into this memory location; zero on error.
521 * @max_packet_size: The maximum allowable packet size
502 * 522 *
503 * Returns zero on success; non-zero on error. 523 * Returns zero on success; non-zero on error.
504 */ 524 */
@@ -515,72 +535,65 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
515 535
516 (*packet_size) = 0; 536 (*packet_size) = 0;
517 (*new_auth_tok) = NULL; 537 (*new_auth_tok) = NULL;
518 538 /**
519 /* we check that: 539 * This format is inspired by OpenPGP; see RFC 2440
520 * one byte for the Tag 1 ID flag 540 * packet tag 1
521 * two bytes for the body size 541 *
522 * do not exceed the maximum_packet_size 542 * Tag 1 identifier (1 byte)
543 * Max Tag 1 packet size (max 3 bytes)
544 * Version (1 byte)
545 * Key identifier (8 bytes; ECRYPTFS_SIG_SIZE)
546 * Cipher identifier (1 byte)
547 * Encrypted key size (arbitrary)
548 *
549 * 12 bytes minimum packet size
523 */ 550 */
524 if (unlikely((*packet_size) + 3 > max_packet_size)) { 551 if (unlikely(max_packet_size < 12)) {
525 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 552 printk(KERN_ERR "Invalid max packet size; must be >=12\n");
526 rc = -EINVAL; 553 rc = -EINVAL;
527 goto out; 554 goto out;
528 } 555 }
529 /* check for Tag 1 identifier - one byte */
530 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) { 556 if (data[(*packet_size)++] != ECRYPTFS_TAG_1_PACKET_TYPE) {
531 ecryptfs_printk(KERN_ERR, "Enter w/ first byte != 0x%.2x\n", 557 printk(KERN_ERR "Enter w/ first byte != 0x%.2x\n",
532 ECRYPTFS_TAG_1_PACKET_TYPE); 558 ECRYPTFS_TAG_1_PACKET_TYPE);
533 rc = -EINVAL; 559 rc = -EINVAL;
534 goto out; 560 goto out;
535 } 561 }
536 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or 562 /* Released: wipe_auth_tok_list called in ecryptfs_parse_packet_set or
537 * at end of function upon failure */ 563 * at end of function upon failure */
538 auth_tok_list_item = 564 auth_tok_list_item =
539 kmem_cache_alloc(ecryptfs_auth_tok_list_item_cache, 565 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache,
540 GFP_KERNEL); 566 GFP_KERNEL);
541 if (!auth_tok_list_item) { 567 if (!auth_tok_list_item) {
542 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); 568 printk(KERN_ERR "Unable to allocate memory\n");
543 rc = -ENOMEM; 569 rc = -ENOMEM;
544 goto out; 570 goto out;
545 } 571 }
546 memset(auth_tok_list_item, 0,
547 sizeof(struct ecryptfs_auth_tok_list_item));
548 (*new_auth_tok) = &auth_tok_list_item->auth_tok; 572 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
549 /* check for body size - one to two bytes
550 *
551 * ***** TAG 1 Packet Format *****
552 * | version number | 1 byte |
553 * | key ID | 8 bytes |
554 * | public key algorithm | 1 byte |
555 * | encrypted session key | arbitrary |
556 */
557 rc = parse_packet_length(&data[(*packet_size)], &body_size, 573 rc = parse_packet_length(&data[(*packet_size)], &body_size,
558 &length_size); 574 &length_size);
559 if (rc) { 575 if (rc) {
560 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " 576 printk(KERN_WARNING "Error parsing packet length; "
561 "rc = [%d]\n", rc); 577 "rc = [%d]\n", rc);
562 goto out_free; 578 goto out_free;
563 } 579 }
564 if (unlikely(body_size < (0x02 + ECRYPTFS_SIG_SIZE))) { 580 if (unlikely(body_size < (ECRYPTFS_SIG_SIZE + 2))) {
565 ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n", 581 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
566 body_size);
567 rc = -EINVAL; 582 rc = -EINVAL;
568 goto out_free; 583 goto out_free;
569 } 584 }
570 (*packet_size) += length_size; 585 (*packet_size) += length_size;
571 if (unlikely((*packet_size) + body_size > max_packet_size)) { 586 if (unlikely((*packet_size) + body_size > max_packet_size)) {
572 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 587 printk(KERN_WARNING "Packet size exceeds max\n");
573 rc = -EINVAL; 588 rc = -EINVAL;
574 goto out_free; 589 goto out_free;
575 } 590 }
576 /* Version 3 (from RFC2440) - one byte */
577 if (unlikely(data[(*packet_size)++] != 0x03)) { 591 if (unlikely(data[(*packet_size)++] != 0x03)) {
578 ecryptfs_printk(KERN_DEBUG, "Unknown version number " 592 printk(KERN_WARNING "Unknown version number [%d]\n",
579 "[%d]\n", data[(*packet_size) - 1]); 593 data[(*packet_size) - 1]);
580 rc = -EINVAL; 594 rc = -EINVAL;
581 goto out_free; 595 goto out_free;
582 } 596 }
583 /* Read Signature */
584 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature, 597 ecryptfs_to_hex((*new_auth_tok)->token.private_key.signature,
585 &data[(*packet_size)], ECRYPTFS_SIG_SIZE); 598 &data[(*packet_size)], ECRYPTFS_SIG_SIZE);
586 *packet_size += ECRYPTFS_SIG_SIZE; 599 *packet_size += ECRYPTFS_SIG_SIZE;
@@ -588,27 +601,23 @@ parse_tag_1_packet(struct ecryptfs_crypt_stat *crypt_stat,
588 * know which public key encryption algorithm was used */ 601 * know which public key encryption algorithm was used */
589 (*packet_size)++; 602 (*packet_size)++;
590 (*new_auth_tok)->session_key.encrypted_key_size = 603 (*new_auth_tok)->session_key.encrypted_key_size =
591 body_size - (0x02 + ECRYPTFS_SIG_SIZE); 604 body_size - (ECRYPTFS_SIG_SIZE + 2);
592 if ((*new_auth_tok)->session_key.encrypted_key_size 605 if ((*new_auth_tok)->session_key.encrypted_key_size
593 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) { 606 > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
594 ecryptfs_printk(KERN_ERR, "Tag 1 packet contains key larger " 607 printk(KERN_WARNING "Tag 1 packet contains key larger "
595 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES"); 608 "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES");
596 rc = -EINVAL; 609 rc = -EINVAL;
597 goto out; 610 goto out;
598 } 611 }
599 ecryptfs_printk(KERN_DEBUG, "Encrypted key size = [%d]\n",
600 (*new_auth_tok)->session_key.encrypted_key_size);
601 memcpy((*new_auth_tok)->session_key.encrypted_key, 612 memcpy((*new_auth_tok)->session_key.encrypted_key,
602 &data[(*packet_size)], (body_size - 0x02 - ECRYPTFS_SIG_SIZE)); 613 &data[(*packet_size)], (body_size - (ECRYPTFS_SIG_SIZE + 2)));
603 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size; 614 (*packet_size) += (*new_auth_tok)->session_key.encrypted_key_size;
604 (*new_auth_tok)->session_key.flags &= 615 (*new_auth_tok)->session_key.flags &=
605 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; 616 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
606 (*new_auth_tok)->session_key.flags |= 617 (*new_auth_tok)->session_key.flags |=
607 ECRYPTFS_CONTAINS_ENCRYPTED_KEY; 618 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
608 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY; 619 (*new_auth_tok)->token_type = ECRYPTFS_PRIVATE_KEY;
609 (*new_auth_tok)->flags |= ECRYPTFS_PRIVATE_KEY; 620 (*new_auth_tok)->flags = 0;
610 /* TODO: Why are we setting this flag here? Don't we want the
611 * userspace to decrypt the session key? */
612 (*new_auth_tok)->session_key.flags &= 621 (*new_auth_tok)->session_key.flags &=
613 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT); 622 ~(ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT);
614 (*new_auth_tok)->session_key.flags &= 623 (*new_auth_tok)->session_key.flags &=
@@ -658,22 +667,30 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
658 667
659 (*packet_size) = 0; 668 (*packet_size) = 0;
660 (*new_auth_tok) = NULL; 669 (*new_auth_tok) = NULL;
661 670 /**
662 /* we check that: 671 *This format is inspired by OpenPGP; see RFC 2440
663 * one byte for the Tag 3 ID flag 672 * packet tag 3
664 * two bytes for the body size 673 *
665 * do not exceed the maximum_packet_size 674 * Tag 3 identifier (1 byte)
675 * Max Tag 3 packet size (max 3 bytes)
676 * Version (1 byte)
677 * Cipher code (1 byte)
678 * S2K specifier (1 byte)
679 * Hash identifier (1 byte)
680 * Salt (ECRYPTFS_SALT_SIZE)
681 * Hash iterations (1 byte)
682 * Encrypted key (arbitrary)
683 *
684 * (ECRYPTFS_SALT_SIZE + 7) minimum packet size
666 */ 685 */
667 if (unlikely((*packet_size) + 3 > max_packet_size)) { 686 if (max_packet_size < (ECRYPTFS_SALT_SIZE + 7)) {
668 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 687 printk(KERN_ERR "Max packet size too large\n");
669 rc = -EINVAL; 688 rc = -EINVAL;
670 goto out; 689 goto out;
671 } 690 }
672
673 /* check for Tag 3 identifyer - one byte */
674 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) { 691 if (data[(*packet_size)++] != ECRYPTFS_TAG_3_PACKET_TYPE) {
675 ecryptfs_printk(KERN_ERR, "Enter w/ first byte != 0x%.2x\n", 692 printk(KERN_ERR "First byte != 0x%.2x; invalid packet\n",
676 ECRYPTFS_TAG_3_PACKET_TYPE); 693 ECRYPTFS_TAG_3_PACKET_TYPE);
677 rc = -EINVAL; 694 rc = -EINVAL;
678 goto out; 695 goto out;
679 } 696 }
@@ -682,56 +699,37 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
682 auth_tok_list_item = 699 auth_tok_list_item =
683 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL); 700 kmem_cache_zalloc(ecryptfs_auth_tok_list_item_cache, GFP_KERNEL);
684 if (!auth_tok_list_item) { 701 if (!auth_tok_list_item) {
685 ecryptfs_printk(KERN_ERR, "Unable to allocate memory\n"); 702 printk(KERN_ERR "Unable to allocate memory\n");
686 rc = -ENOMEM; 703 rc = -ENOMEM;
687 goto out; 704 goto out;
688 } 705 }
689 (*new_auth_tok) = &auth_tok_list_item->auth_tok; 706 (*new_auth_tok) = &auth_tok_list_item->auth_tok;
690
691 /* check for body size - one to two bytes */
692 rc = parse_packet_length(&data[(*packet_size)], &body_size, 707 rc = parse_packet_length(&data[(*packet_size)], &body_size,
693 &length_size); 708 &length_size);
694 if (rc) { 709 if (rc) {
695 ecryptfs_printk(KERN_WARNING, "Error parsing packet length; " 710 printk(KERN_WARNING "Error parsing packet length; rc = [%d]\n",
696 "rc = [%d]\n", rc); 711 rc);
697 goto out_free; 712 goto out_free;
698 } 713 }
699 if (unlikely(body_size < (0x05 + ECRYPTFS_SALT_SIZE))) { 714 if (unlikely(body_size < (ECRYPTFS_SALT_SIZE + 5))) {
700 ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n", 715 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
701 body_size);
702 rc = -EINVAL; 716 rc = -EINVAL;
703 goto out_free; 717 goto out_free;
704 } 718 }
705 (*packet_size) += length_size; 719 (*packet_size) += length_size;
706
707 /* now we know the length of the remainting Tag 3 packet size:
708 * 5 fix bytes for: version string, cipher, S2K ID, hash algo,
709 * number of hash iterations
710 * ECRYPTFS_SALT_SIZE bytes for salt
711 * body_size bytes minus the stuff above is the encrypted key size
712 */
713 if (unlikely((*packet_size) + body_size > max_packet_size)) { 720 if (unlikely((*packet_size) + body_size > max_packet_size)) {
714 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 721 printk(KERN_ERR "Packet size exceeds max\n");
715 rc = -EINVAL; 722 rc = -EINVAL;
716 goto out_free; 723 goto out_free;
717 } 724 }
718
719 /* There are 5 characters of additional information in the
720 * packet */
721 (*new_auth_tok)->session_key.encrypted_key_size = 725 (*new_auth_tok)->session_key.encrypted_key_size =
722 body_size - (0x05 + ECRYPTFS_SALT_SIZE); 726 (body_size - (ECRYPTFS_SALT_SIZE + 5));
723 ecryptfs_printk(KERN_DEBUG, "Encrypted key size = [%d]\n",
724 (*new_auth_tok)->session_key.encrypted_key_size);
725
726 /* Version 4 (from RFC2440) - one byte */
727 if (unlikely(data[(*packet_size)++] != 0x04)) { 727 if (unlikely(data[(*packet_size)++] != 0x04)) {
728 ecryptfs_printk(KERN_DEBUG, "Unknown version number " 728 printk(KERN_WARNING "Unknown version number [%d]\n",
729 "[%d]\n", data[(*packet_size) - 1]); 729 data[(*packet_size) - 1]);
730 rc = -EINVAL; 730 rc = -EINVAL;
731 goto out_free; 731 goto out_free;
732 } 732 }
733
734 /* cipher - one byte */
735 ecryptfs_cipher_code_to_string(crypt_stat->cipher, 733 ecryptfs_cipher_code_to_string(crypt_stat->cipher,
736 (u16)data[(*packet_size)]); 734 (u16)data[(*packet_size)]);
737 /* A little extra work to differentiate among the AES key 735 /* A little extra work to differentiate among the AES key
@@ -745,33 +743,26 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
745 (*new_auth_tok)->session_key.encrypted_key_size; 743 (*new_auth_tok)->session_key.encrypted_key_size;
746 } 744 }
747 ecryptfs_init_crypt_ctx(crypt_stat); 745 ecryptfs_init_crypt_ctx(crypt_stat);
748 /* S2K identifier 3 (from RFC2440) */
749 if (unlikely(data[(*packet_size)++] != 0x03)) { 746 if (unlikely(data[(*packet_size)++] != 0x03)) {
750 ecryptfs_printk(KERN_ERR, "Only S2K ID 3 is currently " 747 printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
751 "supported\n");
752 rc = -ENOSYS; 748 rc = -ENOSYS;
753 goto out_free; 749 goto out_free;
754 } 750 }
755
756 /* TODO: finish the hash mapping */ 751 /* TODO: finish the hash mapping */
757 /* hash algorithm - one byte */
758 switch (data[(*packet_size)++]) { 752 switch (data[(*packet_size)++]) {
759 case 0x01: /* See RFC2440 for these numbers and their mappings */ 753 case 0x01: /* See RFC2440 for these numbers and their mappings */
760 /* Choose MD5 */ 754 /* Choose MD5 */
761 /* salt - ECRYPTFS_SALT_SIZE bytes */
762 memcpy((*new_auth_tok)->token.password.salt, 755 memcpy((*new_auth_tok)->token.password.salt,
763 &data[(*packet_size)], ECRYPTFS_SALT_SIZE); 756 &data[(*packet_size)], ECRYPTFS_SALT_SIZE);
764 (*packet_size) += ECRYPTFS_SALT_SIZE; 757 (*packet_size) += ECRYPTFS_SALT_SIZE;
765
766 /* This conversion was taken straight from RFC2440 */ 758 /* This conversion was taken straight from RFC2440 */
767 /* number of hash iterations - one byte */
768 (*new_auth_tok)->token.password.hash_iterations = 759 (*new_auth_tok)->token.password.hash_iterations =
769 ((u32) 16 + (data[(*packet_size)] & 15)) 760 ((u32) 16 + (data[(*packet_size)] & 15))
770 << ((data[(*packet_size)] >> 4) + 6); 761 << ((data[(*packet_size)] >> 4) + 6);
771 (*packet_size)++; 762 (*packet_size)++;
772 763 /* Friendly reminder:
773 /* encrypted session key - 764 * (*new_auth_tok)->session_key.encrypted_key_size =
774 * (body_size-5-ECRYPTFS_SALT_SIZE) bytes */ 765 * (body_size - (ECRYPTFS_SALT_SIZE + 5)); */
775 memcpy((*new_auth_tok)->session_key.encrypted_key, 766 memcpy((*new_auth_tok)->session_key.encrypted_key,
776 &data[(*packet_size)], 767 &data[(*packet_size)],
777 (*new_auth_tok)->session_key.encrypted_key_size); 768 (*new_auth_tok)->session_key.encrypted_key_size);
@@ -781,7 +772,7 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
781 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY; 772 ~ECRYPTFS_CONTAINS_DECRYPTED_KEY;
782 (*new_auth_tok)->session_key.flags |= 773 (*new_auth_tok)->session_key.flags |=
783 ECRYPTFS_CONTAINS_ENCRYPTED_KEY; 774 ECRYPTFS_CONTAINS_ENCRYPTED_KEY;
784 (*new_auth_tok)->token.password.hash_algo = 0x01; 775 (*new_auth_tok)->token.password.hash_algo = 0x01; /* MD5 */
785 break; 776 break;
786 default: 777 default:
787 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: " 778 ecryptfs_printk(KERN_ERR, "Unsupported hash algorithm: "
@@ -837,82 +828,61 @@ parse_tag_11_packet(unsigned char *data, unsigned char *contents,
837 828
838 (*packet_size) = 0; 829 (*packet_size) = 0;
839 (*tag_11_contents_size) = 0; 830 (*tag_11_contents_size) = 0;
840 831 /* This format is inspired by OpenPGP; see RFC 2440
841 /* check that: 832 * packet tag 11
842 * one byte for the Tag 11 ID flag 833 *
843 * two bytes for the Tag 11 length 834 * Tag 11 identifier (1 byte)
844 * do not exceed the maximum_packet_size 835 * Max Tag 11 packet size (max 3 bytes)
836 * Binary format specifier (1 byte)
837 * Filename length (1 byte)
838 * Filename ("_CONSOLE") (8 bytes)
839 * Modification date (4 bytes)
840 * Literal data (arbitrary)
841 *
842 * We need at least 16 bytes of data for the packet to even be
843 * valid.
845 */ 844 */
846 if (unlikely((*packet_size) + 3 > max_packet_size)) { 845 if (max_packet_size < 16) {
847 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 846 printk(KERN_ERR "Maximum packet size too small\n");
848 rc = -EINVAL; 847 rc = -EINVAL;
849 goto out; 848 goto out;
850 } 849 }
851
852 /* check for Tag 11 identifyer - one byte */
853 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) { 850 if (data[(*packet_size)++] != ECRYPTFS_TAG_11_PACKET_TYPE) {
854 ecryptfs_printk(KERN_WARNING, 851 printk(KERN_WARNING "Invalid tag 11 packet format\n");
855 "Invalid tag 11 packet format\n");
856 rc = -EINVAL; 852 rc = -EINVAL;
857 goto out; 853 goto out;
858 } 854 }
859
860 /* get Tag 11 content length - one or two bytes */
861 rc = parse_packet_length(&data[(*packet_size)], &body_size, 855 rc = parse_packet_length(&data[(*packet_size)], &body_size,
862 &length_size); 856 &length_size);
863 if (rc) { 857 if (rc) {
864 ecryptfs_printk(KERN_WARNING, 858 printk(KERN_WARNING "Invalid tag 11 packet format\n");
865 "Invalid tag 11 packet format\n");
866 goto out; 859 goto out;
867 } 860 }
868 (*packet_size) += length_size; 861 if (body_size < 14) {
869 862 printk(KERN_WARNING "Invalid body size ([%td])\n", body_size);
870 if (body_size < 13) {
871 ecryptfs_printk(KERN_WARNING, "Invalid body size ([%d])\n",
872 body_size);
873 rc = -EINVAL; 863 rc = -EINVAL;
874 goto out; 864 goto out;
875 } 865 }
876 /* We have 13 bytes of surrounding packet values */ 866 (*packet_size) += length_size;
877 (*tag_11_contents_size) = (body_size - 13); 867 (*tag_11_contents_size) = (body_size - 14);
878
879 /* now we know the length of the remainting Tag 11 packet size:
880 * 14 fix bytes for: special flag one, special flag two,
881 * 12 skipped bytes
882 * body_size bytes minus the stuff above is the Tag 11 content
883 */
884 /* FIXME why is the body size one byte smaller than the actual
885 * size of the body?
886 * this seems to be an error here as well as in
887 * write_tag_11_packet() */
888 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) { 868 if (unlikely((*packet_size) + body_size + 1 > max_packet_size)) {
889 ecryptfs_printk(KERN_ERR, "Packet size exceeds max\n"); 869 printk(KERN_ERR "Packet size exceeds max\n");
890 rc = -EINVAL; 870 rc = -EINVAL;
891 goto out; 871 goto out;
892 } 872 }
893
894 /* special flag one - one byte */
895 if (data[(*packet_size)++] != 0x62) { 873 if (data[(*packet_size)++] != 0x62) {
896 ecryptfs_printk(KERN_WARNING, "Unrecognizable packet\n"); 874 printk(KERN_WARNING "Unrecognizable packet\n");
897 rc = -EINVAL; 875 rc = -EINVAL;
898 goto out; 876 goto out;
899 } 877 }
900
901 /* special flag two - one byte */
902 if (data[(*packet_size)++] != 0x08) { 878 if (data[(*packet_size)++] != 0x08) {
903 ecryptfs_printk(KERN_WARNING, "Unrecognizable packet\n"); 879 printk(KERN_WARNING "Unrecognizable packet\n");
904 rc = -EINVAL; 880 rc = -EINVAL;
905 goto out; 881 goto out;
906 } 882 }
907 883 (*packet_size) += 12; /* Ignore filename and modification date */
908 /* skip the next 12 bytes */
909 (*packet_size) += 12; /* We don't care about the filename or
910 * the timestamp */
911
912 /* get the Tag 11 contents - tag_11_contents_size bytes */
913 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size)); 884 memcpy(contents, &data[(*packet_size)], (*tag_11_contents_size));
914 (*packet_size) += (*tag_11_contents_size); 885 (*packet_size) += (*tag_11_contents_size);
915
916out: 886out:
917 if (rc) { 887 if (rc) {
918 (*packet_size) = 0; 888 (*packet_size) = 0;
@@ -921,130 +891,229 @@ out:
921 return rc; 891 return rc;
922} 892}
923 893
894static int
895ecryptfs_find_global_auth_tok_for_sig(
896 struct ecryptfs_global_auth_tok **global_auth_tok,
897 struct ecryptfs_mount_crypt_stat *mount_crypt_stat, char *sig)
898{
899 struct ecryptfs_global_auth_tok *walker;
900 int rc = 0;
901
902 (*global_auth_tok) = NULL;
903 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
904 list_for_each_entry(walker,
905 &mount_crypt_stat->global_auth_tok_list,
906 mount_crypt_stat_list) {
907 if (memcmp(walker->sig, sig, ECRYPTFS_SIG_SIZE_HEX) == 0) {
908 (*global_auth_tok) = walker;
909 goto out;
910 }
911 }
912 rc = -EINVAL;
913out:
914 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
915 return rc;
916}
917
924/** 918/**
925 * decrypt_session_key - Decrypt the session key with the given auth_tok. 919 * ecryptfs_verify_version
920 * @version: The version number to confirm
926 * 921 *
927 * Returns Zero on success; non-zero error otherwise. 922 * Returns zero on good version; non-zero otherwise
928 */ 923 */
929static int decrypt_session_key(struct ecryptfs_auth_tok *auth_tok, 924static int ecryptfs_verify_version(u16 version)
930 struct ecryptfs_crypt_stat *crypt_stat)
931{ 925{
932 struct ecryptfs_password *password_s_ptr; 926 int rc = 0;
933 struct scatterlist src_sg[2], dst_sg[2]; 927 unsigned char major;
934 struct mutex *tfm_mutex = NULL; 928 unsigned char minor;
935 char *encrypted_session_key; 929
936 char *session_key; 930 major = ((version >> 8) & 0xFF);
931 minor = (version & 0xFF);
932 if (major != ECRYPTFS_VERSION_MAJOR) {
933 ecryptfs_printk(KERN_ERR, "Major version number mismatch. "
934 "Expected [%d]; got [%d]\n",
935 ECRYPTFS_VERSION_MAJOR, major);
936 rc = -EINVAL;
937 goto out;
938 }
939 if (minor != ECRYPTFS_VERSION_MINOR) {
940 ecryptfs_printk(KERN_ERR, "Minor version number mismatch. "
941 "Expected [%d]; got [%d]\n",
942 ECRYPTFS_VERSION_MINOR, minor);
943 rc = -EINVAL;
944 goto out;
945 }
946out:
947 return rc;
948}
949
950int ecryptfs_keyring_auth_tok_for_sig(struct key **auth_tok_key,
951 struct ecryptfs_auth_tok **auth_tok,
952 char *sig)
953{
954 int rc = 0;
955
956 (*auth_tok_key) = request_key(&key_type_user, sig, NULL);
957 if (!(*auth_tok_key) || IS_ERR(*auth_tok_key)) {
958 printk(KERN_ERR "Could not find key with description: [%s]\n",
959 sig);
960 process_request_key_err(PTR_ERR(*auth_tok_key));
961 rc = -EINVAL;
962 goto out;
963 }
964 (*auth_tok) = ecryptfs_get_key_payload_data(*auth_tok_key);
965 if (ecryptfs_verify_version((*auth_tok)->version)) {
966 printk(KERN_ERR
967 "Data structure version mismatch. "
968 "Userspace tools must match eCryptfs "
969 "kernel module with major version [%d] "
970 "and minor version [%d]\n",
971 ECRYPTFS_VERSION_MAJOR,
972 ECRYPTFS_VERSION_MINOR);
973 rc = -EINVAL;
974 goto out;
975 }
976 if ((*auth_tok)->token_type != ECRYPTFS_PASSWORD
977 && (*auth_tok)->token_type != ECRYPTFS_PRIVATE_KEY) {
978 printk(KERN_ERR "Invalid auth_tok structure "
979 "returned from key query\n");
980 rc = -EINVAL;
981 goto out;
982 }
983out:
984 return rc;
985}
986
987/**
988 * ecryptfs_find_auth_tok_for_sig
989 * @auth_tok: Set to the matching auth_tok; NULL if not found
990 * @crypt_stat: inode crypt_stat crypto context
991 * @sig: Sig of auth_tok to find
992 *
993 * For now, this function simply looks at the registered auth_tok's
994 * linked off the mount_crypt_stat, so all the auth_toks that can be
995 * used must be registered at mount time. This function could
996 * potentially try a lot harder to find auth_tok's (e.g., by calling
997 * out to ecryptfsd to dynamically retrieve an auth_tok object) so
998 * that static registration of auth_tok's will no longer be necessary.
999 *
1000 * Returns zero on no error; non-zero on error
1001 */
1002static int
1003ecryptfs_find_auth_tok_for_sig(
1004 struct ecryptfs_auth_tok **auth_tok,
1005 struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1006{
1007 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1008 crypt_stat->mount_crypt_stat;
1009 struct ecryptfs_global_auth_tok *global_auth_tok;
1010 int rc = 0;
1011
1012 (*auth_tok) = NULL;
1013 if (ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1014 mount_crypt_stat, sig)) {
1015 struct key *auth_tok_key;
1016
1017 rc = ecryptfs_keyring_auth_tok_for_sig(&auth_tok_key, auth_tok,
1018 sig);
1019 } else
1020 (*auth_tok) = global_auth_tok->global_auth_tok;
1021 return rc;
1022}
1023
1024/**
1025 * decrypt_passphrase_encrypted_session_key - Decrypt the session key with the given auth_tok.
1026 * @auth_tok: The passphrase authentication token to use to encrypt the FEK
1027 * @crypt_stat: The cryptographic context
1028 *
1029 * Returns zero on success; non-zero error otherwise
1030 */
1031static int
1032decrypt_passphrase_encrypted_session_key(struct ecryptfs_auth_tok *auth_tok,
1033 struct ecryptfs_crypt_stat *crypt_stat)
1034{
1035 struct scatterlist dst_sg;
1036 struct scatterlist src_sg;
1037 struct mutex *tfm_mutex;
937 struct blkcipher_desc desc = { 1038 struct blkcipher_desc desc = {
938 .flags = CRYPTO_TFM_REQ_MAY_SLEEP 1039 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
939 }; 1040 };
940 int rc = 0; 1041 int rc = 0;
941 1042
942 password_s_ptr = &auth_tok->token.password; 1043 if (unlikely(ecryptfs_verbosity > 0)) {
943 if (password_s_ptr->flags & ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) 1044 ecryptfs_printk(
944 ecryptfs_printk(KERN_DEBUG, "Session key encryption key " 1045 KERN_DEBUG, "Session key encryption key (size [%d]):\n",
945 "set; skipping key generation\n"); 1046 auth_tok->token.password.session_key_encryption_key_bytes);
946 ecryptfs_printk(KERN_DEBUG, "Session key encryption key (size [%d])" 1047 ecryptfs_dump_hex(
947 ":\n", 1048 auth_tok->token.password.session_key_encryption_key,
948 password_s_ptr->session_key_encryption_key_bytes); 1049 auth_tok->token.password.session_key_encryption_key_bytes);
949 if (ecryptfs_verbosity > 0) 1050 }
950 ecryptfs_dump_hex(password_s_ptr->session_key_encryption_key, 1051 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
951 password_s_ptr-> 1052 crypt_stat->cipher);
952 session_key_encryption_key_bytes); 1053 if (unlikely(rc)) {
953 if (!strcmp(crypt_stat->cipher, 1054 printk(KERN_ERR "Internal error whilst attempting to get "
954 crypt_stat->mount_crypt_stat->global_default_cipher_name) 1055 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
955 && crypt_stat->mount_crypt_stat->global_key_tfm) { 1056 crypt_stat->cipher, rc);
956 desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm; 1057 goto out;
957 tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex;
958 } else {
959 char *full_alg_name;
960
961 rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
962 crypt_stat->cipher,
963 "ecb");
964 if (rc)
965 goto out;
966 desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0,
967 CRYPTO_ALG_ASYNC);
968 kfree(full_alg_name);
969 if (IS_ERR(desc.tfm)) {
970 rc = PTR_ERR(desc.tfm);
971 printk(KERN_ERR "Error allocating crypto context; "
972 "rc = [%d]\n", rc);
973 goto out;
974 }
975 crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY);
976 } 1058 }
977 if (tfm_mutex) 1059 rc = virt_to_scatterlist(auth_tok->session_key.encrypted_key,
978 mutex_lock(tfm_mutex); 1060 auth_tok->session_key.encrypted_key_size,
979 rc = crypto_blkcipher_setkey(desc.tfm, 1061 &src_sg, 1);
980 password_s_ptr->session_key_encryption_key, 1062 if (rc != 1) {
981 crypt_stat->key_size); 1063 printk(KERN_ERR "Internal error whilst attempting to convert "
982 if (rc < 0) { 1064 "auth_tok->session_key.encrypted_key to scatterlist; "
1065 "expected rc = 1; got rc = [%d]. "
1066 "auth_tok->session_key.encrypted_key_size = [%d]\n", rc,
1067 auth_tok->session_key.encrypted_key_size);
1068 goto out;
1069 }
1070 auth_tok->session_key.decrypted_key_size =
1071 auth_tok->session_key.encrypted_key_size;
1072 rc = virt_to_scatterlist(auth_tok->session_key.decrypted_key,
1073 auth_tok->session_key.decrypted_key_size,
1074 &dst_sg, 1);
1075 if (rc != 1) {
1076 printk(KERN_ERR "Internal error whilst attempting to convert "
1077 "auth_tok->session_key.decrypted_key to scatterlist; "
1078 "expected rc = 1; got rc = [%d]\n", rc);
1079 goto out;
1080 }
1081 mutex_lock(tfm_mutex);
1082 rc = crypto_blkcipher_setkey(
1083 desc.tfm, auth_tok->token.password.session_key_encryption_key,
1084 crypt_stat->key_size);
1085 if (unlikely(rc < 0)) {
1086 mutex_unlock(tfm_mutex);
983 printk(KERN_ERR "Error setting key for crypto context\n"); 1087 printk(KERN_ERR "Error setting key for crypto context\n");
984 rc = -EINVAL; 1088 rc = -EINVAL;
985 goto out_free_tfm; 1089 goto out;
986 }
987 /* TODO: virt_to_scatterlist */
988 encrypted_session_key = (char *)__get_free_page(GFP_KERNEL);
989 if (!encrypted_session_key) {
990 ecryptfs_printk(KERN_ERR, "Out of memory\n");
991 rc = -ENOMEM;
992 goto out_free_tfm;
993 } 1090 }
994 session_key = (char *)__get_free_page(GFP_KERNEL); 1091 rc = crypto_blkcipher_decrypt(&desc, &dst_sg, &src_sg,
995 if (!session_key) {
996 kfree(encrypted_session_key);
997 ecryptfs_printk(KERN_ERR, "Out of memory\n");
998 rc = -ENOMEM;
999 goto out_free_tfm;
1000 }
1001 memcpy(encrypted_session_key, auth_tok->session_key.encrypted_key,
1002 auth_tok->session_key.encrypted_key_size);
1003 src_sg[0].page = virt_to_page(encrypted_session_key);
1004 src_sg[0].offset = 0;
1005 BUG_ON(auth_tok->session_key.encrypted_key_size > PAGE_CACHE_SIZE);
1006 src_sg[0].length = auth_tok->session_key.encrypted_key_size;
1007 dst_sg[0].page = virt_to_page(session_key);
1008 dst_sg[0].offset = 0;
1009 auth_tok->session_key.decrypted_key_size =
1010 auth_tok->session_key.encrypted_key_size;
1011 dst_sg[0].length = auth_tok->session_key.encrypted_key_size;
1012 rc = crypto_blkcipher_decrypt(&desc, dst_sg, src_sg,
1013 auth_tok->session_key.encrypted_key_size); 1092 auth_tok->session_key.encrypted_key_size);
1014 if (rc) { 1093 mutex_unlock(tfm_mutex);
1094 if (unlikely(rc)) {
1015 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc); 1095 printk(KERN_ERR "Error decrypting; rc = [%d]\n", rc);
1016 goto out_free_memory; 1096 goto out;
1017 } 1097 }
1018 auth_tok->session_key.decrypted_key_size =
1019 auth_tok->session_key.encrypted_key_size;
1020 memcpy(auth_tok->session_key.decrypted_key, session_key,
1021 auth_tok->session_key.decrypted_key_size);
1022 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY; 1098 auth_tok->session_key.flags |= ECRYPTFS_CONTAINS_DECRYPTED_KEY;
1023 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key, 1099 memcpy(crypt_stat->key, auth_tok->session_key.decrypted_key,
1024 auth_tok->session_key.decrypted_key_size); 1100 auth_tok->session_key.decrypted_key_size);
1025 crypt_stat->flags |= ECRYPTFS_KEY_VALID; 1101 crypt_stat->flags |= ECRYPTFS_KEY_VALID;
1026 ecryptfs_printk(KERN_DEBUG, "Decrypted session key:\n"); 1102 if (unlikely(ecryptfs_verbosity > 0)) {
1027 if (ecryptfs_verbosity > 0) 1103 ecryptfs_printk(KERN_DEBUG, "FEK of size [%d]:\n",
1104 crypt_stat->key_size);
1028 ecryptfs_dump_hex(crypt_stat->key, 1105 ecryptfs_dump_hex(crypt_stat->key,
1029 crypt_stat->key_size); 1106 crypt_stat->key_size);
1030out_free_memory: 1107 }
1031 memset(encrypted_session_key, 0, PAGE_CACHE_SIZE);
1032 free_page((unsigned long)encrypted_session_key);
1033 memset(session_key, 0, PAGE_CACHE_SIZE);
1034 free_page((unsigned long)session_key);
1035out_free_tfm:
1036 if (tfm_mutex)
1037 mutex_unlock(tfm_mutex);
1038 else
1039 crypto_free_blkcipher(desc.tfm);
1040out: 1108out:
1041 return rc; 1109 return rc;
1042} 1110}
1043 1111
1044/** 1112/**
1045 * ecryptfs_parse_packet_set 1113 * ecryptfs_parse_packet_set
1046 * @dest: The header page in memory 1114 * @crypt_stat: The cryptographic context
1047 * @version: Version of file format, to guide parsing behavior 1115 * @src: Virtual address of region of memory containing the packets
1116 * @ecryptfs_dentry: The eCryptfs dentry associated with the packet set
1048 * 1117 *
1049 * Get crypt_stat to have the file's session key if the requisite key 1118 * Get crypt_stat to have the file's session key if the requisite key
1050 * is available to decrypt the session key. 1119 * is available to decrypt the session key.
@@ -1058,25 +1127,22 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1058 struct dentry *ecryptfs_dentry) 1127 struct dentry *ecryptfs_dentry)
1059{ 1128{
1060 size_t i = 0; 1129 size_t i = 0;
1061 size_t found_auth_tok = 0; 1130 size_t found_auth_tok;
1062 size_t next_packet_is_auth_tok_packet; 1131 size_t next_packet_is_auth_tok_packet;
1063 char sig[ECRYPTFS_SIG_SIZE_HEX];
1064 struct list_head auth_tok_list; 1132 struct list_head auth_tok_list;
1065 struct list_head *walker; 1133 struct ecryptfs_auth_tok *matching_auth_tok;
1066 struct ecryptfs_auth_tok *chosen_auth_tok = NULL; 1134 struct ecryptfs_auth_tok *candidate_auth_tok;
1067 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 1135 char *candidate_auth_tok_sig;
1068 &ecryptfs_superblock_to_private(
1069 ecryptfs_dentry->d_sb)->mount_crypt_stat;
1070 struct ecryptfs_auth_tok *candidate_auth_tok = NULL;
1071 size_t packet_size; 1136 size_t packet_size;
1072 struct ecryptfs_auth_tok *new_auth_tok; 1137 struct ecryptfs_auth_tok *new_auth_tok;
1073 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE]; 1138 unsigned char sig_tmp_space[ECRYPTFS_SIG_SIZE];
1139 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1074 size_t tag_11_contents_size; 1140 size_t tag_11_contents_size;
1075 size_t tag_11_packet_size; 1141 size_t tag_11_packet_size;
1076 int rc = 0; 1142 int rc = 0;
1077 1143
1078 INIT_LIST_HEAD(&auth_tok_list); 1144 INIT_LIST_HEAD(&auth_tok_list);
1079 /* Parse the header to find as many packets as we can, these will be 1145 /* Parse the header to find as many packets as we can; these will be
1080 * added the our &auth_tok_list */ 1146 * added the our &auth_tok_list */
1081 next_packet_is_auth_tok_packet = 1; 1147 next_packet_is_auth_tok_packet = 1;
1082 while (next_packet_is_auth_tok_packet) { 1148 while (next_packet_is_auth_tok_packet) {
@@ -1155,73 +1221,85 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
1155 } 1221 }
1156 } 1222 }
1157 if (list_empty(&auth_tok_list)) { 1223 if (list_empty(&auth_tok_list)) {
1158 rc = -EINVAL; /* Do not support non-encrypted files in 1224 printk(KERN_ERR "The lower file appears to be a non-encrypted "
1159 * the 0.1 release */ 1225 "eCryptfs file; this is not supported in this version "
1226 "of the eCryptfs kernel module\n");
1227 rc = -EINVAL;
1160 goto out; 1228 goto out;
1161 } 1229 }
1162 /* If we have a global auth tok, then we should try to use 1230 /* auth_tok_list contains the set of authentication tokens
1163 * it */ 1231 * parsed from the metadata. We need to find a matching
1164 if (mount_crypt_stat->global_auth_tok) { 1232 * authentication token that has the secret component(s)
1165 memcpy(sig, mount_crypt_stat->global_auth_tok_sig, 1233 * necessary to decrypt the EFEK in the auth_tok parsed from
1166 ECRYPTFS_SIG_SIZE_HEX); 1234 * the metadata. There may be several potential matches, but
1167 chosen_auth_tok = mount_crypt_stat->global_auth_tok; 1235 * just one will be sufficient to decrypt to get the FEK. */
1168 } else 1236find_next_matching_auth_tok:
1169 BUG(); /* We should always have a global auth tok in 1237 found_auth_tok = 0;
1170 * the 0.1 release */ 1238 list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
1171 /* Scan list to see if our chosen_auth_tok works */
1172 list_for_each(walker, &auth_tok_list) {
1173 struct ecryptfs_auth_tok_list_item *auth_tok_list_item;
1174 auth_tok_list_item =
1175 list_entry(walker, struct ecryptfs_auth_tok_list_item,
1176 list);
1177 candidate_auth_tok = &auth_tok_list_item->auth_tok; 1239 candidate_auth_tok = &auth_tok_list_item->auth_tok;
1178 if (unlikely(ecryptfs_verbosity > 0)) { 1240 if (unlikely(ecryptfs_verbosity > 0)) {
1179 ecryptfs_printk(KERN_DEBUG, 1241 ecryptfs_printk(KERN_DEBUG,
1180 "Considering cadidate auth tok:\n"); 1242 "Considering cadidate auth tok:\n");
1181 ecryptfs_dump_auth_tok(candidate_auth_tok); 1243 ecryptfs_dump_auth_tok(candidate_auth_tok);
1182 } 1244 }
1183 /* TODO: Replace ECRYPTFS_SIG_SIZE_HEX w/ dynamic value */ 1245 rc = ecryptfs_get_auth_tok_sig(&candidate_auth_tok_sig,
1184 if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD 1246 candidate_auth_tok);
1185 && !strncmp(candidate_auth_tok->token.password.signature, 1247 if (rc) {
1186 sig, ECRYPTFS_SIG_SIZE_HEX)) { 1248 printk(KERN_ERR
1187 found_auth_tok = 1; 1249 "Unrecognized candidate auth tok type: [%d]\n",
1188 goto leave_list; 1250 candidate_auth_tok->token_type);
1189 /* TODO: Transfer the common salt into the 1251 rc = -EINVAL;
1190 * crypt_stat salt */ 1252 goto out_wipe_list;
1191 } else if ((candidate_auth_tok->token_type 1253 }
1192 == ECRYPTFS_PRIVATE_KEY) 1254 ecryptfs_find_auth_tok_for_sig(&matching_auth_tok, crypt_stat,
1193 && !strncmp(candidate_auth_tok->token.private_key.signature, 1255 candidate_auth_tok_sig);
1194 sig, ECRYPTFS_SIG_SIZE_HEX)) { 1256 if (matching_auth_tok) {
1195 found_auth_tok = 1; 1257 found_auth_tok = 1;
1196 goto leave_list; 1258 goto found_matching_auth_tok;
1197 } 1259 }
1198 } 1260 }
1199 if (!found_auth_tok) { 1261 if (!found_auth_tok) {
1200 ecryptfs_printk(KERN_ERR, "Could not find authentication " 1262 ecryptfs_printk(KERN_ERR, "Could not find a usable "
1201 "token on temporary list for sig [%.*s]\n", 1263 "authentication token\n");
1202 ECRYPTFS_SIG_SIZE_HEX, sig);
1203 rc = -EIO; 1264 rc = -EIO;
1204 goto out_wipe_list; 1265 goto out_wipe_list;
1205 } 1266 }
1206leave_list: 1267found_matching_auth_tok:
1207 rc = -ENOTSUPP;
1208 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { 1268 if (candidate_auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1209 memcpy(&(candidate_auth_tok->token.private_key), 1269 memcpy(&(candidate_auth_tok->token.private_key),
1210 &(chosen_auth_tok->token.private_key), 1270 &(matching_auth_tok->token.private_key),
1211 sizeof(struct ecryptfs_private_key)); 1271 sizeof(struct ecryptfs_private_key));
1212 rc = decrypt_pki_encrypted_session_key(mount_crypt_stat, 1272 rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
1213 candidate_auth_tok,
1214 crypt_stat); 1273 crypt_stat);
1215 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) { 1274 } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
1216 memcpy(&(candidate_auth_tok->token.password), 1275 memcpy(&(candidate_auth_tok->token.password),
1217 &(chosen_auth_tok->token.password), 1276 &(matching_auth_tok->token.password),
1218 sizeof(struct ecryptfs_password)); 1277 sizeof(struct ecryptfs_password));
1219 rc = decrypt_session_key(candidate_auth_tok, crypt_stat); 1278 rc = decrypt_passphrase_encrypted_session_key(
1279 candidate_auth_tok, crypt_stat);
1220 } 1280 }
1221 if (rc) { 1281 if (rc) {
1222 ecryptfs_printk(KERN_ERR, "Error decrypting the " 1282 struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
1223 "session key; rc = [%d]\n", rc); 1283
1224 goto out_wipe_list; 1284 ecryptfs_printk(KERN_WARNING, "Error decrypting the "
1285 "session key for authentication token with sig "
1286 "[%.*s]; rc = [%d]. Removing auth tok "
1287 "candidate from the list and searching for "
1288 "the next match.\n", candidate_auth_tok_sig,
1289 ECRYPTFS_SIG_SIZE_HEX, rc);
1290 list_for_each_entry_safe(auth_tok_list_item,
1291 auth_tok_list_item_tmp,
1292 &auth_tok_list, list) {
1293 if (candidate_auth_tok
1294 == &auth_tok_list_item->auth_tok) {
1295 list_del(&auth_tok_list_item->list);
1296 kmem_cache_free(
1297 ecryptfs_auth_tok_list_item_cache,
1298 auth_tok_list_item);
1299 goto find_next_matching_auth_tok;
1300 }
1301 }
1302 BUG();
1225 } 1303 }
1226 rc = ecryptfs_compute_root_iv(crypt_stat); 1304 rc = ecryptfs_compute_root_iv(crypt_stat);
1227 if (rc) { 1305 if (rc) {
@@ -1240,6 +1318,7 @@ out_wipe_list:
1240out: 1318out:
1241 return rc; 1319 return rc;
1242} 1320}
1321
1243static int 1322static int
1244pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok, 1323pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
1245 struct ecryptfs_crypt_stat *crypt_stat, 1324 struct ecryptfs_crypt_stat *crypt_stat,
@@ -1284,22 +1363,25 @@ out:
1284/** 1363/**
1285 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet 1364 * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
1286 * @dest: Buffer into which to write the packet 1365 * @dest: Buffer into which to write the packet
1287 * @max: Maximum number of bytes that can be writtn 1366 * @remaining_bytes: Maximum number of bytes that can be writtn
1367 * @auth_tok: The authentication token used for generating the tag 1 packet
1368 * @crypt_stat: The cryptographic context
1369 * @key_rec: The key record struct for the tag 1 packet
1288 * @packet_size: This function will write the number of bytes that end 1370 * @packet_size: This function will write the number of bytes that end
1289 * up constituting the packet; set to zero on error 1371 * up constituting the packet; set to zero on error
1290 * 1372 *
1291 * Returns zero on success; non-zero on error. 1373 * Returns zero on success; non-zero on error.
1292 */ 1374 */
1293static int 1375static int
1294write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, 1376write_tag_1_packet(char *dest, size_t *remaining_bytes,
1377 struct ecryptfs_auth_tok *auth_tok,
1295 struct ecryptfs_crypt_stat *crypt_stat, 1378 struct ecryptfs_crypt_stat *crypt_stat,
1296 struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
1297 struct ecryptfs_key_record *key_rec, size_t *packet_size) 1379 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1298{ 1380{
1299 size_t i; 1381 size_t i;
1300 size_t encrypted_session_key_valid = 0; 1382 size_t encrypted_session_key_valid = 0;
1301 size_t key_rec_size;
1302 size_t packet_size_length; 1383 size_t packet_size_length;
1384 size_t max_packet_size;
1303 int rc = 0; 1385 int rc = 0;
1304 1386
1305 (*packet_size) = 0; 1387 (*packet_size) = 0;
@@ -1329,37 +1411,23 @@ write_tag_1_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
1329 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size); 1411 ecryptfs_dump_hex(key_rec->enc_key, key_rec->enc_key_size);
1330 } 1412 }
1331encrypted_session_key_set: 1413encrypted_session_key_set:
1332 /* Now we have a valid key_rec. Append it to the 1414 /* This format is inspired by OpenPGP; see RFC 2440
1333 * key_rec set. */ 1415 * packet tag 1 */
1334 key_rec_size = (sizeof(struct ecryptfs_key_record) 1416 max_packet_size = (1 /* Tag 1 identifier */
1335 - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 1417 + 3 /* Max Tag 1 packet size */
1336 + (key_rec->enc_key_size)); 1418 + 1 /* Version */
1337 /* TODO: Include a packet size limit as a parameter to this 1419 + ECRYPTFS_SIG_SIZE /* Key identifier */
1338 * function once we have multi-packet headers (for versions 1420 + 1 /* Cipher identifier */
1339 * later than 0.1 */ 1421 + key_rec->enc_key_size); /* Encrypted key size */
1340 if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) { 1422 if (max_packet_size > (*remaining_bytes)) {
1341 ecryptfs_printk(KERN_ERR, "Keyset too large\n"); 1423 printk(KERN_ERR "Packet length larger than maximum allowable; "
1342 rc = -EINVAL; 1424 "need up to [%td] bytes, but there are only [%td] "
1343 goto out; 1425 "available\n", max_packet_size, (*remaining_bytes));
1344 }
1345 /* ***** TAG 1 Packet Format *****
1346 * | version number | 1 byte |
1347 * | key ID | 8 bytes |
1348 * | public key algorithm | 1 byte |
1349 * | encrypted session key | arbitrary |
1350 */
1351 if ((0x02 + ECRYPTFS_SIG_SIZE + key_rec->enc_key_size) >= max) {
1352 ecryptfs_printk(KERN_ERR,
1353 "Authentication token is too large\n");
1354 rc = -EINVAL; 1426 rc = -EINVAL;
1355 goto out; 1427 goto out;
1356 } 1428 }
1357 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE; 1429 dest[(*packet_size)++] = ECRYPTFS_TAG_1_PACKET_TYPE;
1358 /* This format is inspired by OpenPGP; see RFC 2440 1430 rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
1359 * packet tag 1 */
1360 rc = write_packet_length(&dest[(*packet_size)],
1361 (0x02 + ECRYPTFS_SIG_SIZE +
1362 key_rec->enc_key_size),
1363 &packet_size_length); 1431 &packet_size_length);
1364 if (rc) { 1432 if (rc) {
1365 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet " 1433 ecryptfs_printk(KERN_ERR, "Error generating tag 1 packet "
@@ -1377,13 +1445,15 @@ encrypted_session_key_set:
1377out: 1445out:
1378 if (rc) 1446 if (rc)
1379 (*packet_size) = 0; 1447 (*packet_size) = 0;
1448 else
1449 (*remaining_bytes) -= (*packet_size);
1380 return rc; 1450 return rc;
1381} 1451}
1382 1452
1383/** 1453/**
1384 * write_tag_11_packet 1454 * write_tag_11_packet
1385 * @dest: Target into which Tag 11 packet is to be written 1455 * @dest: Target into which Tag 11 packet is to be written
1386 * @max: Maximum packet length 1456 * @remaining_bytes: Maximum packet length
1387 * @contents: Byte array of contents to copy in 1457 * @contents: Byte array of contents to copy in
1388 * @contents_length: Number of bytes in contents 1458 * @contents_length: Number of bytes in contents
1389 * @packet_length: Length of the Tag 11 packet written; zero on error 1459 * @packet_length: Length of the Tag 11 packet written; zero on error
@@ -1391,54 +1461,59 @@ out:
1391 * Returns zero on success; non-zero on error. 1461 * Returns zero on success; non-zero on error.
1392 */ 1462 */
1393static int 1463static int
1394write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length, 1464write_tag_11_packet(char *dest, size_t *remaining_bytes, char *contents,
1395 size_t *packet_length) 1465 size_t contents_length, size_t *packet_length)
1396{ 1466{
1397 size_t packet_size_length; 1467 size_t packet_size_length;
1468 size_t max_packet_size;
1398 int rc = 0; 1469 int rc = 0;
1399 1470
1400 (*packet_length) = 0; 1471 (*packet_length) = 0;
1401 if ((13 + contents_length) > max) { 1472 /* This format is inspired by OpenPGP; see RFC 2440
1473 * packet tag 11 */
1474 max_packet_size = (1 /* Tag 11 identifier */
1475 + 3 /* Max Tag 11 packet size */
1476 + 1 /* Binary format specifier */
1477 + 1 /* Filename length */
1478 + 8 /* Filename ("_CONSOLE") */
1479 + 4 /* Modification date */
1480 + contents_length); /* Literal data */
1481 if (max_packet_size > (*remaining_bytes)) {
1482 printk(KERN_ERR "Packet length larger than maximum allowable; "
1483 "need up to [%td] bytes, but there are only [%td] "
1484 "available\n", max_packet_size, (*remaining_bytes));
1402 rc = -EINVAL; 1485 rc = -EINVAL;
1403 ecryptfs_printk(KERN_ERR, "Packet length larger than "
1404 "maximum allowable\n");
1405 goto out; 1486 goto out;
1406 } 1487 }
1407 /* General packet header */
1408 /* Packet tag */
1409 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE; 1488 dest[(*packet_length)++] = ECRYPTFS_TAG_11_PACKET_TYPE;
1410 /* Packet length */
1411 rc = write_packet_length(&dest[(*packet_length)], 1489 rc = write_packet_length(&dest[(*packet_length)],
1412 (13 + contents_length), &packet_size_length); 1490 (max_packet_size - 4), &packet_size_length);
1413 if (rc) { 1491 if (rc) {
1414 ecryptfs_printk(KERN_ERR, "Error generating tag 11 packet " 1492 printk(KERN_ERR "Error generating tag 11 packet header; cannot "
1415 "header; cannot generate packet length\n"); 1493 "generate packet length. rc = [%d]\n", rc);
1416 goto out; 1494 goto out;
1417 } 1495 }
1418 (*packet_length) += packet_size_length; 1496 (*packet_length) += packet_size_length;
1419 /* Tag 11 specific */ 1497 dest[(*packet_length)++] = 0x62; /* binary data format specifier */
1420 /* One-octet field that describes how the data is formatted */
1421 dest[(*packet_length)++] = 0x62; /* binary data */
1422 /* One-octet filename length followed by filename */
1423 dest[(*packet_length)++] = 8; 1498 dest[(*packet_length)++] = 8;
1424 memcpy(&dest[(*packet_length)], "_CONSOLE", 8); 1499 memcpy(&dest[(*packet_length)], "_CONSOLE", 8);
1425 (*packet_length) += 8; 1500 (*packet_length) += 8;
1426 /* Four-octet number indicating modification date */
1427 memset(&dest[(*packet_length)], 0x00, 4); 1501 memset(&dest[(*packet_length)], 0x00, 4);
1428 (*packet_length) += 4; 1502 (*packet_length) += 4;
1429 /* Remainder is literal data */
1430 memcpy(&dest[(*packet_length)], contents, contents_length); 1503 memcpy(&dest[(*packet_length)], contents, contents_length);
1431 (*packet_length) += contents_length; 1504 (*packet_length) += contents_length;
1432 out: 1505 out:
1433 if (rc) 1506 if (rc)
1434 (*packet_length) = 0; 1507 (*packet_length) = 0;
1508 else
1509 (*remaining_bytes) -= (*packet_length);
1435 return rc; 1510 return rc;
1436} 1511}
1437 1512
1438/** 1513/**
1439 * write_tag_3_packet 1514 * write_tag_3_packet
1440 * @dest: Buffer into which to write the packet 1515 * @dest: Buffer into which to write the packet
1441 * @max: Maximum number of bytes that can be written 1516 * @remaining_bytes: Maximum number of bytes that can be written
1442 * @auth_tok: Authentication token 1517 * @auth_tok: Authentication token
1443 * @crypt_stat: The cryptographic context 1518 * @crypt_stat: The cryptographic context
1444 * @key_rec: encrypted key 1519 * @key_rec: encrypted key
@@ -1448,19 +1523,22 @@ write_tag_11_packet(char *dest, int max, char *contents, size_t contents_length,
1448 * Returns zero on success; non-zero on error. 1523 * Returns zero on success; non-zero on error.
1449 */ 1524 */
1450static int 1525static int
1451write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok, 1526write_tag_3_packet(char *dest, size_t *remaining_bytes,
1527 struct ecryptfs_auth_tok *auth_tok,
1452 struct ecryptfs_crypt_stat *crypt_stat, 1528 struct ecryptfs_crypt_stat *crypt_stat,
1453 struct ecryptfs_key_record *key_rec, size_t *packet_size) 1529 struct ecryptfs_key_record *key_rec, size_t *packet_size)
1454{ 1530{
1455 size_t i; 1531 size_t i;
1456 size_t encrypted_session_key_valid = 0; 1532 size_t encrypted_session_key_valid = 0;
1457 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES]; 1533 char session_key_encryption_key[ECRYPTFS_MAX_KEY_BYTES];
1458 struct scatterlist dest_sg[2]; 1534 struct scatterlist dst_sg;
1459 struct scatterlist src_sg[2]; 1535 struct scatterlist src_sg;
1460 struct mutex *tfm_mutex = NULL; 1536 struct mutex *tfm_mutex = NULL;
1461 size_t key_rec_size;
1462 size_t packet_size_length;
1463 size_t cipher_code; 1537 size_t cipher_code;
1538 size_t packet_size_length;
1539 size_t max_packet_size;
1540 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1541 crypt_stat->mount_crypt_stat;
1464 struct blkcipher_desc desc = { 1542 struct blkcipher_desc desc = {
1465 .tfm = NULL, 1543 .tfm = NULL,
1466 .flags = CRYPTO_TFM_REQ_MAY_SLEEP 1544 .flags = CRYPTO_TFM_REQ_MAY_SLEEP
@@ -1470,16 +1548,25 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
1470 (*packet_size) = 0; 1548 (*packet_size) = 0;
1471 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature, 1549 ecryptfs_from_hex(key_rec->sig, auth_tok->token.password.signature,
1472 ECRYPTFS_SIG_SIZE); 1550 ECRYPTFS_SIG_SIZE);
1473 encrypted_session_key_valid = 0; 1551 rc = ecryptfs_get_tfm_and_mutex_for_cipher_name(&desc.tfm, &tfm_mutex,
1474 for (i = 0; i < crypt_stat->key_size; i++) 1552 crypt_stat->cipher);
1475 encrypted_session_key_valid |= 1553 if (unlikely(rc)) {
1476 auth_tok->session_key.encrypted_key[i]; 1554 printk(KERN_ERR "Internal error whilst attempting to get "
1477 if (encrypted_session_key_valid) { 1555 "tfm and mutex for cipher name [%s]; rc = [%d]\n",
1478 memcpy(key_rec->enc_key, 1556 crypt_stat->cipher, rc);
1479 auth_tok->session_key.encrypted_key, 1557 goto out;
1480 auth_tok->session_key.encrypted_key_size); 1558 }
1481 goto encrypted_session_key_set; 1559 if (mount_crypt_stat->global_default_cipher_key_size == 0) {
1560 struct blkcipher_alg *alg = crypto_blkcipher_alg(desc.tfm);
1561
1562 printk(KERN_WARNING "No key size specified at mount; "
1563 "defaulting to [%d]\n", alg->max_keysize);
1564 mount_crypt_stat->global_default_cipher_key_size =
1565 alg->max_keysize;
1482 } 1566 }
1567 if (crypt_stat->key_size == 0)
1568 crypt_stat->key_size =
1569 mount_crypt_stat->global_default_cipher_key_size;
1483 if (auth_tok->session_key.encrypted_key_size == 0) 1570 if (auth_tok->session_key.encrypted_key_size == 0)
1484 auth_tok->session_key.encrypted_key_size = 1571 auth_tok->session_key.encrypted_key_size =
1485 crypt_stat->key_size; 1572 crypt_stat->key_size;
@@ -1487,9 +1574,24 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
1487 && strcmp("aes", crypt_stat->cipher) == 0) { 1574 && strcmp("aes", crypt_stat->cipher) == 0) {
1488 memset((crypt_stat->key + 24), 0, 8); 1575 memset((crypt_stat->key + 24), 0, 8);
1489 auth_tok->session_key.encrypted_key_size = 32; 1576 auth_tok->session_key.encrypted_key_size = 32;
1490 } 1577 } else
1578 auth_tok->session_key.encrypted_key_size = crypt_stat->key_size;
1491 key_rec->enc_key_size = 1579 key_rec->enc_key_size =
1492 auth_tok->session_key.encrypted_key_size; 1580 auth_tok->session_key.encrypted_key_size;
1581 encrypted_session_key_valid = 0;
1582 for (i = 0; i < auth_tok->session_key.encrypted_key_size; i++)
1583 encrypted_session_key_valid |=
1584 auth_tok->session_key.encrypted_key[i];
1585 if (encrypted_session_key_valid) {
1586 ecryptfs_printk(KERN_DEBUG, "encrypted_session_key_valid != 0; "
1587 "using auth_tok->session_key.encrypted_key, "
1588 "where key_rec->enc_key_size = [%d]\n",
1589 key_rec->enc_key_size);
1590 memcpy(key_rec->enc_key,
1591 auth_tok->session_key.encrypted_key,
1592 key_rec->enc_key_size);
1593 goto encrypted_session_key_set;
1594 }
1493 if (auth_tok->token.password.flags & 1595 if (auth_tok->token.password.flags &
1494 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) { 1596 ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET) {
1495 ecryptfs_printk(KERN_DEBUG, "Using previously generated " 1597 ecryptfs_printk(KERN_DEBUG, "Using previously generated "
@@ -1508,54 +1610,32 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
1508 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n"); 1610 ecryptfs_printk(KERN_DEBUG, "Session key encryption key:\n");
1509 ecryptfs_dump_hex(session_key_encryption_key, 16); 1611 ecryptfs_dump_hex(session_key_encryption_key, 16);
1510 } 1612 }
1511 rc = virt_to_scatterlist(crypt_stat->key, 1613 rc = virt_to_scatterlist(crypt_stat->key, key_rec->enc_key_size,
1512 key_rec->enc_key_size, src_sg, 2); 1614 &src_sg, 1);
1513 if (!rc) { 1615 if (rc != 1) {
1514 ecryptfs_printk(KERN_ERR, "Error generating scatterlist " 1616 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1515 "for crypt_stat session key\n"); 1617 "for crypt_stat session key; expected rc = 1; "
1618 "got rc = [%d]. key_rec->enc_key_size = [%d]\n",
1619 rc, key_rec->enc_key_size);
1516 rc = -ENOMEM; 1620 rc = -ENOMEM;
1517 goto out; 1621 goto out;
1518 } 1622 }
1519 rc = virt_to_scatterlist(key_rec->enc_key, 1623 rc = virt_to_scatterlist(key_rec->enc_key, key_rec->enc_key_size,
1520 key_rec->enc_key_size, dest_sg, 2); 1624 &dst_sg, 1);
1521 if (!rc) { 1625 if (rc != 1) {
1522 ecryptfs_printk(KERN_ERR, "Error generating scatterlist " 1626 ecryptfs_printk(KERN_ERR, "Error generating scatterlist "
1523 "for crypt_stat encrypted session key\n"); 1627 "for crypt_stat encrypted session key; "
1628 "expected rc = 1; got rc = [%d]. "
1629 "key_rec->enc_key_size = [%d]\n", rc,
1630 key_rec->enc_key_size);
1524 rc = -ENOMEM; 1631 rc = -ENOMEM;
1525 goto out; 1632 goto out;
1526 } 1633 }
1527 if (!strcmp(crypt_stat->cipher, 1634 mutex_lock(tfm_mutex);
1528 crypt_stat->mount_crypt_stat->global_default_cipher_name)
1529 && crypt_stat->mount_crypt_stat->global_key_tfm) {
1530 desc.tfm = crypt_stat->mount_crypt_stat->global_key_tfm;
1531 tfm_mutex = &crypt_stat->mount_crypt_stat->global_key_tfm_mutex;
1532 } else {
1533 char *full_alg_name;
1534
1535 rc = ecryptfs_crypto_api_algify_cipher_name(&full_alg_name,
1536 crypt_stat->cipher,
1537 "ecb");
1538 if (rc)
1539 goto out;
1540 desc.tfm = crypto_alloc_blkcipher(full_alg_name, 0,
1541 CRYPTO_ALG_ASYNC);
1542 kfree(full_alg_name);
1543 if (IS_ERR(desc.tfm)) {
1544 rc = PTR_ERR(desc.tfm);
1545 ecryptfs_printk(KERN_ERR, "Could not initialize crypto "
1546 "context for cipher [%s]; rc = [%d]\n",
1547 crypt_stat->cipher, rc);
1548 goto out;
1549 }
1550 crypto_blkcipher_set_flags(desc.tfm, CRYPTO_TFM_REQ_WEAK_KEY);
1551 }
1552 if (tfm_mutex)
1553 mutex_lock(tfm_mutex);
1554 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key, 1635 rc = crypto_blkcipher_setkey(desc.tfm, session_key_encryption_key,
1555 crypt_stat->key_size); 1636 crypt_stat->key_size);
1556 if (rc < 0) { 1637 if (rc < 0) {
1557 if (tfm_mutex) 1638 mutex_unlock(tfm_mutex);
1558 mutex_unlock(tfm_mutex);
1559 ecryptfs_printk(KERN_ERR, "Error setting key for crypto " 1639 ecryptfs_printk(KERN_ERR, "Error setting key for crypto "
1560 "context; rc = [%d]\n", rc); 1640 "context; rc = [%d]\n", rc);
1561 goto out; 1641 goto out;
@@ -1563,56 +1643,53 @@ write_tag_3_packet(char *dest, size_t max, struct ecryptfs_auth_tok *auth_tok,
1563 rc = 0; 1643 rc = 0;
1564 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n", 1644 ecryptfs_printk(KERN_DEBUG, "Encrypting [%d] bytes of the key\n",
1565 crypt_stat->key_size); 1645 crypt_stat->key_size);
1566 rc = crypto_blkcipher_encrypt(&desc, dest_sg, src_sg, 1646 rc = crypto_blkcipher_encrypt(&desc, &dst_sg, &src_sg,
1567 (*key_rec).enc_key_size); 1647 (*key_rec).enc_key_size);
1648 mutex_unlock(tfm_mutex);
1568 if (rc) { 1649 if (rc) {
1569 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc); 1650 printk(KERN_ERR "Error encrypting; rc = [%d]\n", rc);
1570 goto out; 1651 goto out;
1571 } 1652 }
1572 if (tfm_mutex)
1573 mutex_unlock(tfm_mutex);
1574 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n"); 1653 ecryptfs_printk(KERN_DEBUG, "This should be the encrypted key:\n");
1575 if (ecryptfs_verbosity > 0) 1654 if (ecryptfs_verbosity > 0) {
1655 ecryptfs_printk(KERN_DEBUG, "EFEK of size [%d]:\n",
1656 key_rec->enc_key_size);
1576 ecryptfs_dump_hex(key_rec->enc_key, 1657 ecryptfs_dump_hex(key_rec->enc_key,
1577 key_rec->enc_key_size); 1658 key_rec->enc_key_size);
1578encrypted_session_key_set:
1579 /* Now we have a valid key_rec. Append it to the
1580 * key_rec set. */
1581 key_rec_size = (sizeof(struct ecryptfs_key_record)
1582 - ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES
1583 + (key_rec->enc_key_size));
1584 /* TODO: Include a packet size limit as a parameter to this
1585 * function once we have multi-packet headers (for versions
1586 * later than 0.1 */
1587 if (key_rec_size >= ECRYPTFS_MAX_KEYSET_SIZE) {
1588 ecryptfs_printk(KERN_ERR, "Keyset too large\n");
1589 rc = -EINVAL;
1590 goto out;
1591 } 1659 }
1592 /* TODO: Packet size limit */ 1660encrypted_session_key_set:
1593 /* We have 5 bytes of surrounding packet data */ 1661 /* This format is inspired by OpenPGP; see RFC 2440
1594 if ((0x05 + ECRYPTFS_SALT_SIZE 1662 * packet tag 3 */
1595 + key_rec->enc_key_size) >= max) { 1663 max_packet_size = (1 /* Tag 3 identifier */
1596 ecryptfs_printk(KERN_ERR, "Authentication token is too " 1664 + 3 /* Max Tag 3 packet size */
1597 "large\n"); 1665 + 1 /* Version */
1666 + 1 /* Cipher code */
1667 + 1 /* S2K specifier */
1668 + 1 /* Hash identifier */
1669 + ECRYPTFS_SALT_SIZE /* Salt */
1670 + 1 /* Hash iterations */
1671 + key_rec->enc_key_size); /* Encrypted key size */
1672 if (max_packet_size > (*remaining_bytes)) {
1673 printk(KERN_ERR "Packet too large; need up to [%td] bytes, but "
1674 "there are only [%td] available\n", max_packet_size,
1675 (*remaining_bytes));
1598 rc = -EINVAL; 1676 rc = -EINVAL;
1599 goto out; 1677 goto out;
1600 } 1678 }
1601 /* This format is inspired by OpenPGP; see RFC 2440
1602 * packet tag 3 */
1603 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE; 1679 dest[(*packet_size)++] = ECRYPTFS_TAG_3_PACKET_TYPE;
1604 /* ver+cipher+s2k+hash+salt+iter+enc_key */ 1680 /* Chop off the Tag 3 identifier(1) and Tag 3 packet size(3)
1605 rc = write_packet_length(&dest[(*packet_size)], 1681 * to get the number of octets in the actual Tag 3 packet */
1606 (0x05 + ECRYPTFS_SALT_SIZE 1682 rc = write_packet_length(&dest[(*packet_size)], (max_packet_size - 4),
1607 + key_rec->enc_key_size),
1608 &packet_size_length); 1683 &packet_size_length);
1609 if (rc) { 1684 if (rc) {
1610 ecryptfs_printk(KERN_ERR, "Error generating tag 3 packet " 1685 printk(KERN_ERR "Error generating tag 3 packet header; cannot "
1611 "header; cannot generate packet length\n"); 1686 "generate packet length. rc = [%d]\n", rc);
1612 goto out; 1687 goto out;
1613 } 1688 }
1614 (*packet_size) += packet_size_length; 1689 (*packet_size) += packet_size_length;
1615 dest[(*packet_size)++] = 0x04; /* version 4 */ 1690 dest[(*packet_size)++] = 0x04; /* version 4 */
1691 /* TODO: Break from RFC2440 so that arbitrary ciphers can be
1692 * specified with strings */
1616 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat); 1693 cipher_code = ecryptfs_code_for_cipher_string(crypt_stat);
1617 if (cipher_code == 0) { 1694 if (cipher_code == 0) {
1618 ecryptfs_printk(KERN_WARNING, "Unable to generate code for " 1695 ecryptfs_printk(KERN_WARNING, "Unable to generate code for "
@@ -1631,10 +1708,10 @@ encrypted_session_key_set:
1631 key_rec->enc_key_size); 1708 key_rec->enc_key_size);
1632 (*packet_size) += key_rec->enc_key_size; 1709 (*packet_size) += key_rec->enc_key_size;
1633out: 1710out:
1634 if (desc.tfm && !tfm_mutex)
1635 crypto_free_blkcipher(desc.tfm);
1636 if (rc) 1711 if (rc)
1637 (*packet_size) = 0; 1712 (*packet_size) = 0;
1713 else
1714 (*remaining_bytes) -= (*packet_size);
1638 return rc; 1715 return rc;
1639} 1716}
1640 1717
@@ -1642,7 +1719,7 @@ struct kmem_cache *ecryptfs_key_record_cache;
1642 1719
1643/** 1720/**
1644 * ecryptfs_generate_key_packet_set 1721 * ecryptfs_generate_key_packet_set
1645 * @dest: Virtual address from which to write the key record set 1722 * @dest_base: Virtual address from which to write the key record set
1646 * @crypt_stat: The cryptographic context from which the 1723 * @crypt_stat: The cryptographic context from which the
1647 * authentication tokens will be retrieved 1724 * authentication tokens will be retrieved
1648 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat 1725 * @ecryptfs_dentry: The dentry, used to retrieve the mount crypt stat
@@ -1662,24 +1739,43 @@ ecryptfs_generate_key_packet_set(char *dest_base,
1662 size_t max) 1739 size_t max)
1663{ 1740{
1664 struct ecryptfs_auth_tok *auth_tok; 1741 struct ecryptfs_auth_tok *auth_tok;
1742 struct ecryptfs_global_auth_tok *global_auth_tok;
1665 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = 1743 struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
1666 &ecryptfs_superblock_to_private( 1744 &ecryptfs_superblock_to_private(
1667 ecryptfs_dentry->d_sb)->mount_crypt_stat; 1745 ecryptfs_dentry->d_sb)->mount_crypt_stat;
1668 size_t written; 1746 size_t written;
1669 struct ecryptfs_key_record *key_rec; 1747 struct ecryptfs_key_record *key_rec;
1748 struct ecryptfs_key_sig *key_sig;
1670 int rc = 0; 1749 int rc = 0;
1671 1750
1672 (*len) = 0; 1751 (*len) = 0;
1752 mutex_lock(&crypt_stat->keysig_list_mutex);
1673 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL); 1753 key_rec = kmem_cache_alloc(ecryptfs_key_record_cache, GFP_KERNEL);
1674 if (!key_rec) { 1754 if (!key_rec) {
1675 rc = -ENOMEM; 1755 rc = -ENOMEM;
1676 goto out; 1756 goto out;
1677 } 1757 }
1678 if (mount_crypt_stat->global_auth_tok) { 1758 list_for_each_entry(key_sig, &crypt_stat->keysig_list,
1679 auth_tok = mount_crypt_stat->global_auth_tok; 1759 crypt_stat_list) {
1760 memset(key_rec, 0, sizeof(*key_rec));
1761 rc = ecryptfs_find_global_auth_tok_for_sig(&global_auth_tok,
1762 mount_crypt_stat,
1763 key_sig->keysig);
1764 if (rc) {
1765 printk(KERN_ERR "Error attempting to get the global "
1766 "auth_tok; rc = [%d]\n", rc);
1767 goto out_free;
1768 }
1769 if (global_auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID) {
1770 printk(KERN_WARNING
1771 "Skipping invalid auth tok with sig = [%s]\n",
1772 global_auth_tok->sig);
1773 continue;
1774 }
1775 auth_tok = global_auth_tok->global_auth_tok;
1680 if (auth_tok->token_type == ECRYPTFS_PASSWORD) { 1776 if (auth_tok->token_type == ECRYPTFS_PASSWORD) {
1681 rc = write_tag_3_packet((dest_base + (*len)), 1777 rc = write_tag_3_packet((dest_base + (*len)),
1682 max, auth_tok, 1778 &max, auth_tok,
1683 crypt_stat, key_rec, 1779 crypt_stat, key_rec,
1684 &written); 1780 &written);
1685 if (rc) { 1781 if (rc) {
@@ -1689,10 +1785,9 @@ ecryptfs_generate_key_packet_set(char *dest_base,
1689 } 1785 }
1690 (*len) += written; 1786 (*len) += written;
1691 /* Write auth tok signature packet */ 1787 /* Write auth tok signature packet */
1692 rc = write_tag_11_packet( 1788 rc = write_tag_11_packet((dest_base + (*len)), &max,
1693 (dest_base + (*len)), 1789 key_rec->sig,
1694 (max - (*len)), 1790 ECRYPTFS_SIG_SIZE, &written);
1695 key_rec->sig, ECRYPTFS_SIG_SIZE, &written);
1696 if (rc) { 1791 if (rc) {
1697 ecryptfs_printk(KERN_ERR, "Error writing " 1792 ecryptfs_printk(KERN_ERR, "Error writing "
1698 "auth tok signature packet\n"); 1793 "auth tok signature packet\n");
@@ -1701,9 +1796,8 @@ ecryptfs_generate_key_packet_set(char *dest_base,
1701 (*len) += written; 1796 (*len) += written;
1702 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) { 1797 } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
1703 rc = write_tag_1_packet(dest_base + (*len), 1798 rc = write_tag_1_packet(dest_base + (*len),
1704 max, auth_tok, 1799 &max, auth_tok,
1705 crypt_stat,mount_crypt_stat, 1800 crypt_stat, key_rec, &written);
1706 key_rec, &written);
1707 if (rc) { 1801 if (rc) {
1708 ecryptfs_printk(KERN_WARNING, "Error " 1802 ecryptfs_printk(KERN_WARNING, "Error "
1709 "writing tag 1 packet\n"); 1803 "writing tag 1 packet\n");
@@ -1716,19 +1810,69 @@ ecryptfs_generate_key_packet_set(char *dest_base,
1716 rc = -EINVAL; 1810 rc = -EINVAL;
1717 goto out_free; 1811 goto out_free;
1718 } 1812 }
1719 } else 1813 }
1720 BUG(); 1814 if (likely(max > 0)) {
1721 if (likely((max - (*len)) > 0)) {
1722 dest_base[(*len)] = 0x00; 1815 dest_base[(*len)] = 0x00;
1723 } else { 1816 } else {
1724 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n"); 1817 ecryptfs_printk(KERN_ERR, "Error writing boundary byte\n");
1725 rc = -EIO; 1818 rc = -EIO;
1726 } 1819 }
1727
1728out_free: 1820out_free:
1729 kmem_cache_free(ecryptfs_key_record_cache, key_rec); 1821 kmem_cache_free(ecryptfs_key_record_cache, key_rec);
1730out: 1822out:
1731 if (rc) 1823 if (rc)
1732 (*len) = 0; 1824 (*len) = 0;
1825 mutex_unlock(&crypt_stat->keysig_list_mutex);
1733 return rc; 1826 return rc;
1734} 1827}
1828
1829struct kmem_cache *ecryptfs_key_sig_cache;
1830
1831int ecryptfs_add_keysig(struct ecryptfs_crypt_stat *crypt_stat, char *sig)
1832{
1833 struct ecryptfs_key_sig *new_key_sig;
1834 int rc = 0;
1835
1836 new_key_sig = kmem_cache_alloc(ecryptfs_key_sig_cache, GFP_KERNEL);
1837 if (!new_key_sig) {
1838 rc = -ENOMEM;
1839 printk(KERN_ERR
1840 "Error allocating from ecryptfs_key_sig_cache\n");
1841 goto out;
1842 }
1843 memcpy(new_key_sig->keysig, sig, ECRYPTFS_SIG_SIZE_HEX);
1844 mutex_lock(&crypt_stat->keysig_list_mutex);
1845 list_add(&new_key_sig->crypt_stat_list, &crypt_stat->keysig_list);
1846 mutex_unlock(&crypt_stat->keysig_list_mutex);
1847out:
1848 return rc;
1849}
1850
1851struct kmem_cache *ecryptfs_global_auth_tok_cache;
1852
1853int
1854ecryptfs_add_global_auth_tok(struct ecryptfs_mount_crypt_stat *mount_crypt_stat,
1855 char *sig)
1856{
1857 struct ecryptfs_global_auth_tok *new_auth_tok;
1858 int rc = 0;
1859
1860 new_auth_tok = kmem_cache_alloc(ecryptfs_global_auth_tok_cache,
1861 GFP_KERNEL);
1862 if (!new_auth_tok) {
1863 rc = -ENOMEM;
1864 printk(KERN_ERR "Error allocating from "
1865 "ecryptfs_global_auth_tok_cache\n");
1866 goto out;
1867 }
1868 memcpy(new_auth_tok->sig, sig, ECRYPTFS_SIG_SIZE_HEX);
1869 new_auth_tok->sig[ECRYPTFS_SIG_SIZE_HEX] = '\0';
1870 mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
1871 list_add(&new_auth_tok->mount_crypt_stat_list,
1872 &mount_crypt_stat->global_auth_tok_list);
1873 mount_crypt_stat->num_global_auth_toks++;
1874 mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
1875out:
1876 return rc;
1877}
1878
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-07 01:47:05 -0500