1 // SPDX-License-Identifier: BSD-2-Clause
2 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3 *
4 * LibTomCrypt is a library that provides various cryptographic
5 * algorithms in a highly modular and flexible manner.
6 *
7 * The library is free for all purposes without any express
8 * guarantee it works.
9 */
10
11 /**
12 @file ocb_encrypt_authenticate_memory.c
13 OCB implementation, encrypt block of memory, by Tom St Denis
14 */
15 #include "tomcrypt_private.h"
16
17 #ifdef LTC_OCB_MODE
18
19 /**
20 Encrypt and generate an authentication code for a buffer of memory
21 @param cipher The index of the cipher desired
22 @param key The secret key
23 @param keylen The length of the secret key (octets)
24 @param nonce The session nonce (length of the block ciphers block size)
25 @param pt The plaintext
26 @param ptlen The length of the plaintext (octets)
27 @param ct [out] The ciphertext
28 @param tag [out] The authentication tag
29 @param taglen [in/out] The max size and resulting size of the authentication tag
30 @return CRYPT_OK if successful
31 */
ocb_encrypt_authenticate_memory(int cipher,const unsigned char * key,unsigned long keylen,const unsigned char * nonce,const unsigned char * pt,unsigned long ptlen,unsigned char * ct,unsigned char * tag,unsigned long * taglen)32 int ocb_encrypt_authenticate_memory(int cipher,
33 const unsigned char *key, unsigned long keylen,
34 const unsigned char *nonce,
35 const unsigned char *pt, unsigned long ptlen,
36 unsigned char *ct,
37 unsigned char *tag, unsigned long *taglen)
38 {
39 int err;
40 ocb_state *ocb;
41
42 LTC_ARGCHK(key != NULL);
43 LTC_ARGCHK(nonce != NULL);
44 LTC_ARGCHK(pt != NULL);
45 LTC_ARGCHK(ct != NULL);
46 LTC_ARGCHK(tag != NULL);
47 LTC_ARGCHK(taglen != NULL);
48
49 /* allocate ram */
50 ocb = XMALLOC(sizeof(ocb_state));
51 if (ocb == NULL) {
52 return CRYPT_MEM;
53 }
54
55 if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {
56 goto LBL_ERR;
57 }
58
59 while (ptlen > (unsigned long)ocb->block_len) {
60 if ((err = ocb_encrypt(ocb, pt, ct)) != CRYPT_OK) {
61 goto LBL_ERR;
62 }
63 ptlen -= ocb->block_len;
64 pt += ocb->block_len;
65 ct += ocb->block_len;
66 }
67
68 err = ocb_done_encrypt(ocb, pt, ptlen, ct, tag, taglen);
69 LBL_ERR:
70 #ifdef LTC_CLEAN_STACK
71 zeromem(ocb, sizeof(ocb_state));
72 #endif
73
74 XFREE(ocb);
75
76 return err;
77 }
78
79 #endif
80
81 /* ref: $Format:%D$ */
82 /* git commit: $Format:%H$ */
83 /* commit time: $Format:%ai$ */
84