1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3
4 /**
5 @file ocb3_encrypt_authenticate_memory.c
6 OCB implementation, encrypt block of memory, by Tom St Denis
7 */
8 #include "tomcrypt_private.h"
9
10 #ifdef LTC_OCB3_MODE
11
12 /**
13 Encrypt and generate an authentication code for a buffer of memory
14 @param cipher The index of the cipher desired
15 @param key The secret key
16 @param keylen The length of the secret key (octets)
17 @param nonce The session nonce (length of the block ciphers block size)
18 @param noncelen The length of the nonce (octets)
19 @param adata The AAD - additional associated data
20 @param adatalen The length of AAD (octets)
21 @param pt The plaintext
22 @param ptlen The length of the plaintext (octets)
23 @param ct [out] The ciphertext
24 @param tag [out] The authentication tag
25 @param taglen [in/out] The max size and resulting size of the authentication tag
26 @return CRYPT_OK if successful
27 */
ocb3_encrypt_authenticate_memory(int cipher,const unsigned char * key,unsigned long keylen,const unsigned char * nonce,unsigned long noncelen,const unsigned char * adata,unsigned long adatalen,const unsigned char * pt,unsigned long ptlen,unsigned char * ct,unsigned char * tag,unsigned long * taglen)28 int ocb3_encrypt_authenticate_memory(int cipher,
29 const unsigned char *key, unsigned long keylen,
30 const unsigned char *nonce, unsigned long noncelen,
31 const unsigned char *adata, unsigned long adatalen,
32 const unsigned char *pt, unsigned long ptlen,
33 unsigned char *ct,
34 unsigned char *tag, unsigned long *taglen)
35 {
36 int err;
37 ocb3_state *ocb;
38
39 LTC_ARGCHK(taglen != NULL);
40
41 /* allocate memory */
42 ocb = XMALLOC(sizeof(ocb3_state));
43 if (ocb == NULL) {
44 return CRYPT_MEM;
45 }
46
47 if ((err = ocb3_init(ocb, cipher, key, keylen, nonce, noncelen, *taglen)) != CRYPT_OK) {
48 goto LBL_ERR;
49 }
50
51 if (adata != NULL || adatalen != 0) {
52 if ((err = ocb3_add_aad(ocb, adata, adatalen)) != CRYPT_OK) {
53 goto LBL_ERR;
54 }
55 }
56
57 if ((err = ocb3_encrypt_last(ocb, pt, ptlen, ct)) != CRYPT_OK) {
58 goto LBL_ERR;
59 }
60
61 err = ocb3_done(ocb, tag, taglen);
62
63 LBL_ERR:
64 #ifdef LTC_CLEAN_STACK
65 zeromem(ocb, sizeof(ocb3_state));
66 #endif
67
68 XFREE(ocb);
69 return err;
70 }
71
72 #endif
73