mirror of
https://github.com/Laupetin/OpenAssetTools.git
synced 2025-04-21 16:45:44 +00:00
50 lines
1.5 KiB
C
50 lines
1.5 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
|
|
*
|
|
* LibTomCrypt is a library that provides various cryptographic
|
|
* algorithms in a highly modular and flexible manner.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*/
|
|
|
|
#include "tomcrypt.h"
|
|
|
|
#ifdef LTC_CHACHA20POLY1305_MODE
|
|
|
|
/**
|
|
Decrypt bytes of ciphertext with ChaCha20Poly1305
|
|
@param st The ChaCha20Poly1305 state
|
|
@param in The ciphertext
|
|
@param inlen The length of the input (octets)
|
|
@param out [out] The plaintext (length inlen)
|
|
@return CRYPT_OK if successful
|
|
*/
|
|
int chacha20poly1305_decrypt(chacha20poly1305_state *st, const unsigned char *in, unsigned long inlen, unsigned char *out)
|
|
{
|
|
unsigned char padzero[16] = { 0 };
|
|
unsigned long padlen;
|
|
int err;
|
|
|
|
if (inlen == 0) return CRYPT_OK; /* nothing to do */
|
|
LTC_ARGCHK(st != NULL);
|
|
|
|
if (st->aadflg) {
|
|
padlen = 16 - (unsigned long)(st->aadlen % 16);
|
|
if (padlen < 16) {
|
|
if ((err = poly1305_process(&st->poly, padzero, padlen)) != CRYPT_OK) return err;
|
|
}
|
|
st->aadflg = 0; /* no more AAD */
|
|
}
|
|
if (st->aadflg) st->aadflg = 0; /* no more AAD */
|
|
if ((err = poly1305_process(&st->poly, in, inlen)) != CRYPT_OK) return err;
|
|
if ((err = chacha_crypt(&st->chacha, in, inlen, out)) != CRYPT_OK) return err;
|
|
st->ctlen += (ulong64)inlen;
|
|
return CRYPT_OK;
|
|
}
|
|
|
|
#endif
|
|
|
|
/* ref: HEAD -> master, tag: v1.18.2 */
|
|
/* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */
|
|
/* commit time: 2018-07-01 22:49:01 +0200 */
|