38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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#include "tomcrypt_private.h"
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#ifdef LTC_CHACHA20POLY1305_MODE
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/**
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Encrypt bytes of ciphertext with ChaCha20Poly1305
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@param st The ChaCha20Poly1305 state
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@param in The plaintext
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@param inlen The length of the input (octets)
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@param out [out] The ciphertext (length inlen)
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@return CRYPT_OK if successful
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*/
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int chacha20poly1305_encrypt(chacha20poly1305_state *st, const unsigned char *in, unsigned long inlen, unsigned char *out)
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{
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unsigned char padzero[16] = { 0 };
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unsigned long padlen;
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int err;
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LTC_ARGCHK(st != NULL);
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if ((err = chacha_crypt(&st->chacha, in, inlen, out)) != CRYPT_OK) return err;
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if (st->aadflg) {
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padlen = 16 - (unsigned long)(st->aadlen % 16);
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if (padlen < 16) {
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if ((err = poly1305_process(&st->poly, padzero, padlen)) != CRYPT_OK) return err;
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}
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st->aadflg = 0; /* no more AAD */
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}
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if ((err = poly1305_process(&st->poly, out, inlen)) != CRYPT_OK) return err;
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st->ctlen += (ulong64)inlen;
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return CRYPT_OK;
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}
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#endif
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