Mercurial > dropbear
view libtomcrypt/src/encauth/chachapoly/chacha20poly1305_setiv_rfc7905.c @ 1552:e46f7f1da56a
CHANGES for 2018.76
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 27 Feb 2018 22:14:04 +0800 |
parents | 6dba84798cd5 |
children |
line wrap: on
line source
/* 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 /** Set IV + counter data (with RFC7905-magic) to the ChaCha20Poly1305 state and reset the context @param st The ChaCha20Poly1305 state @param iv The IV data to add @param ivlen The length of the IV (must be 12 or 8) @param sequence_number 64bit sequence number which is incorporated into IV as described in RFC7905 @return CRYPT_OK on success */ int chacha20poly1305_setiv_rfc7905(chacha20poly1305_state *st, const unsigned char *iv, unsigned long ivlen, ulong64 sequence_number) { int i; unsigned char combined_iv[12] = { 0 }; LTC_ARGCHK(st != NULL); LTC_ARGCHK(iv != NULL); LTC_ARGCHK(ivlen == 12); STORE64L(sequence_number, combined_iv + 4); for (i = 0; i < 12; i++) combined_iv[i] = iv[i] ^ combined_iv[i]; return chacha20poly1305_setiv(st, combined_iv, 12); } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */