Mercurial > dropbear
view libtomcrypt/src/encauth/chachapoly/chacha20poly1305_decrypt.c @ 1765:b688c884dad7
Fix fuzz-sshpacketmutator to work
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Mon, 26 Oct 2020 22:52:07 +0800 |
parents | 6dba84798cd5 |
children |
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/* 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: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */