| // SPDX-License-Identifier: BSD-2-Clause |
| /* 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. |
| */ |
| |
| /* The implementation is based on: |
| * chacha-ref.c version 20080118 |
| * Public domain from D. J. Bernstein |
| */ |
| |
| #include "tomcrypt_private.h" |
| |
| #ifdef LTC_CHACHA |
| |
| /** |
| Set IV + counter data to the ChaCha state |
| @param st The ChaCha20 state |
| @param iv The IV data to add |
| @param ivlen The length of the IV (must be 8) |
| @param counter 64bit (unsigned) initial counter value |
| @return CRYPT_OK on success |
| */ |
| int chacha_ivctr64(chacha_state *st, const unsigned char *iv, unsigned long ivlen, ulong64 counter) |
| { |
| LTC_ARGCHK(st != NULL); |
| LTC_ARGCHK(iv != NULL); |
| /* 64bit IV + 64bit counter */ |
| LTC_ARGCHK(ivlen == 8); |
| |
| st->input[12] = (ulong32)(counter & 0xFFFFFFFF); |
| st->input[13] = (ulong32)(counter >> 32); |
| LOAD32L(st->input[14], iv + 0); |
| LOAD32L(st->input[15], iv + 4); |
| st->ksleft = 0; |
| st->ivlen = ivlen; |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |