1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3
4 #include "tomcrypt_private.h"
5
6 #ifdef LTC_CHACHA20POLY1305_MODE
7
8 /**
9 Process an entire GCM packet in one call.
10 @param key The secret key
11 @param keylen The length of the secret key
12 @param iv The initialization vector
13 @param ivlen The length of the initialization vector
14 @param aad The additional authentication data (header)
15 @param aadlen The length of the aad
16 @param in The plaintext
17 @param inlen The length of the plaintext (ciphertext length is the same)
18 @param out The ciphertext
19 @param tag [out] The MAC tag
20 @param taglen [in/out] The MAC tag length
21 @param direction Encrypt or Decrypt mode (CHACHA20POLY1305_ENCRYPT or CHACHA20POLY1305_DECRYPT)
22 @return CRYPT_OK on success
23 */
chacha20poly1305_memory(const unsigned char * key,unsigned long keylen,const unsigned char * iv,unsigned long ivlen,const unsigned char * aad,unsigned long aadlen,const unsigned char * in,unsigned long inlen,unsigned char * out,unsigned char * tag,unsigned long * taglen,int direction)24 int chacha20poly1305_memory(const unsigned char *key, unsigned long keylen,
25 const unsigned char *iv, unsigned long ivlen,
26 const unsigned char *aad, unsigned long aadlen,
27 const unsigned char *in, unsigned long inlen,
28 unsigned char *out,
29 unsigned char *tag, unsigned long *taglen,
30 int direction)
31 {
32 chacha20poly1305_state st;
33 int err;
34
35 LTC_ARGCHK(key != NULL);
36 LTC_ARGCHK(iv != NULL);
37 LTC_ARGCHK(in != NULL);
38 LTC_ARGCHK(out != NULL);
39 LTC_ARGCHK(tag != NULL);
40 LTC_ARGCHK(taglen != NULL);
41
42 if ((err = chacha20poly1305_init(&st, key, keylen)) != CRYPT_OK) { goto LBL_ERR; }
43 if ((err = chacha20poly1305_setiv(&st, iv, ivlen)) != CRYPT_OK) { goto LBL_ERR; }
44 if (aad && aadlen > 0) {
45 if ((err = chacha20poly1305_add_aad(&st, aad, aadlen)) != CRYPT_OK) { goto LBL_ERR; }
46 }
47 if (direction == CHACHA20POLY1305_ENCRYPT) {
48 if ((err = chacha20poly1305_encrypt(&st, in, inlen, out)) != CRYPT_OK) { goto LBL_ERR; }
49 if ((err = chacha20poly1305_done(&st, tag, taglen)) != CRYPT_OK) { goto LBL_ERR; }
50 }
51 else if (direction == CHACHA20POLY1305_DECRYPT) {
52 unsigned char buf[MAXBLOCKSIZE];
53 unsigned long buflen = sizeof(buf);
54 if ((err = chacha20poly1305_decrypt(&st, in, inlen, out)) != CRYPT_OK) { goto LBL_ERR; }
55 if ((err = chacha20poly1305_done(&st, buf, &buflen)) != CRYPT_OK) { goto LBL_ERR; }
56 if (buflen != *taglen || XMEM_NEQ(buf, tag, buflen) != 0) {
57 err = CRYPT_ERROR;
58 goto LBL_ERR;
59 }
60 }
61 else {
62 err = CRYPT_INVALID_ARG;
63 goto LBL_ERR;
64 }
65 LBL_ERR:
66 #ifdef LTC_CLEAN_STACK
67 zeromem(&st, sizeof(chacha20poly1305_state));
68 #endif
69 return err;
70 }
71
72 #endif
73