annotate src/encauth/ocb/ocb_decrypt_verify_memory.c @ 192:9cc34777b479 libtomcrypt

propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9) to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author Matt Johnston <matt@ucc.asn.au>
date Sun, 08 May 2005 06:36:47 +0000
parents 1c15b283127b
children 39d5d58461d6
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
191
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2 *
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 * LibTomCrypt is a library that provides various cryptographic
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4 * algorithms in a highly modular and flexible manner.
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 *
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 * The library is free for all purposes without any express
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7 * guarantee it works.
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 *
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9 * Tom St Denis, [email protected], http://libtomcrypt.org
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 */
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12 /**
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 @file ocb_decrypt_verify_memory.c
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 OCB implementation, helper to decrypt block of memory, by Tom St Denis
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 */
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 #include "tomcrypt.h"
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18 #ifdef OCB_MODE
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20 /**
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 Decrypt and compare the tag with OCB.
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22 @param cipher The index of the cipher desired
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23 @param key The secret key
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 @param keylen The length of the secret key (octets)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 @param nonce The session nonce (length of the block size of the block cipher)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26 @param ct The ciphertext
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 @param ctlen The length of the ciphertext (octets)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 @param pt [out] The plaintext
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29 @param tag The tag to compare against
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30 @param taglen The length of the tag (octets)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31 @param stat [out] The result of the tag comparison (1==valid, 0==invalid)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32 @return CRYPT_OK if successful regardless of the tag comparison
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33 */
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34 int ocb_decrypt_verify_memory(int cipher,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 const unsigned char *key, unsigned long keylen,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36 const unsigned char *nonce,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 const unsigned char *ct, unsigned long ctlen,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38 unsigned char *pt,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39 const unsigned char *tag, unsigned long taglen,
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40 int *stat)
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41 {
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
42 int err;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
43 ocb_state *ocb;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
44
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
45 LTC_ARGCHK(key != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
46 LTC_ARGCHK(nonce != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
47 LTC_ARGCHK(pt != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
48 LTC_ARGCHK(ct != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
49 LTC_ARGCHK(tag != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
50 LTC_ARGCHK(stat != NULL);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
51
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
52 /* allocate memory */
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
53 ocb = XMALLOC(sizeof(ocb_state));
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
54 if (ocb == NULL) {
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
55 return CRYPT_MEM;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
56 }
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
57
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
58 if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
59 goto LBL_ERR;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
60 }
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
61
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
62 while (ctlen > (unsigned long)ocb->block_len) {
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
63 if ((err = ocb_decrypt(ocb, ct, pt)) != CRYPT_OK) {
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
64 goto LBL_ERR;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
65 }
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
66 ctlen -= ocb->block_len;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
67 pt += ocb->block_len;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
68 ct += ocb->block_len;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
69 }
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
70
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
71 err = ocb_done_decrypt(ocb, ct, ctlen, pt, tag, taglen, stat);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
72 LBL_ERR:
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
73 #ifdef LTC_CLEAN_STACK
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
74 zeromem(ocb, sizeof(ocb_state));
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
75 #endif
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
76
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
77 XFREE(ocb);
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
78
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
79 return err;
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
80 }
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
81
1c15b283127b Import of libtomcrypt 1.02 with manual path rename rearrangement etc
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
82 #endif