1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3
4 #include "tomcrypt_private.h"
5
6 #ifdef LTC_CHACHA
7
8 /**
9 Encrypt (or decrypt) bytes of ciphertext (or plaintext) with ChaCha
10 @param key The key
11 @param keylen The key length
12 @param iv The initial vector
13 @param ivlen The initial vector length
14 @param datain The plaintext (or ciphertext)
15 @param datalen The length of the input and output (octets)
16 @param rounds The number of rounds
17 @param dataout [out] The ciphertext (or plaintext)
18 @return CRYPT_OK if successful
19 */
chacha_memory(const unsigned char * key,unsigned long keylen,unsigned long rounds,const unsigned char * iv,unsigned long ivlen,ulong64 counter,const unsigned char * datain,unsigned long datalen,unsigned char * dataout)20 int chacha_memory(const unsigned char *key, unsigned long keylen, unsigned long rounds,
21 const unsigned char *iv, unsigned long ivlen, ulong64 counter,
22 const unsigned char *datain, unsigned long datalen, unsigned char *dataout)
23 {
24 chacha_state st;
25 int err;
26
27 LTC_ARGCHK(ivlen <= 8 || counter < 4294967296); /* 2**32 */
28
29 if ((err = chacha_setup(&st, key, keylen, rounds)) != CRYPT_OK) goto WIPE_KEY;
30 if (ivlen > 8) {
31 if ((err = chacha_ivctr32(&st, iv, ivlen, (ulong32)counter)) != CRYPT_OK) goto WIPE_KEY;
32 } else {
33 if ((err = chacha_ivctr64(&st, iv, ivlen, counter)) != CRYPT_OK) goto WIPE_KEY;
34 }
35 err = chacha_crypt(&st, datain, datalen, dataout);
36 WIPE_KEY:
37 chacha_done(&st);
38 return err;
39 }
40
41 #endif /* LTC_CHACHA */
42