528 lines
13 KiB
C
528 lines
13 KiB
C
/*
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* Copyright (c) 2024 Lucas Gabriel Vuotto <lucas@lgv5.net>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <limits.h>
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#include <string.h>
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#include "internal.h"
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#include "util.h"
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/*
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* Implements ChaCha20-Poly1305 according to RFC 8439, XChaCha20-Poly1305
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* according to draft-irtf-cfrg-xchacha-03.
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*/
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enum aead_mode {
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AEAD_SEAL,
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AEAD_OPEN,
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};
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static int
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chacha20_poly1305_anycrypt_init(void *arg, void *initparams, enum aead_mode m)
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{
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struct lc_chacha20_poly1305_params *params = initparams;
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struct chacha20_poly1305_state *state = arg;
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struct lc_chacha20_params cparams;
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struct lc_poly1305_params aparams;
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size_t olen;
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if (params->cipher->impl != lc_cipher_impl_chacha20() ||
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params->auth->impl != lc_auth_impl_poly1305())
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return 0;
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state->auth = params->auth;
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state->cipher = params->cipher;
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state->aadlen = state->ctlen = 0;
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state->aaddone = 0;
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memcpy(cparams.key, params->key, sizeof(params->key));
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memcpy(cparams.nonce, params->nonce, sizeof(params->nonce));
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cparams.counter = 0;
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if (!lc_cipher_encrypt(state->cipher->impl, aparams.key, &olen,
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&cparams, zerobuf, LC_POLY1305_KEYLEN))
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return 0;
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if (!lc_auth_init(state->auth, &aparams))
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return 0;
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cparams.counter = 1;
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switch (m) {
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case AEAD_SEAL:
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if (!lc_cipher_encrypt_init(state->cipher, &cparams))
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return 0;
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break;
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case AEAD_OPEN:
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if (!lc_cipher_decrypt_init(state->cipher, &cparams))
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return 0;
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break;
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default:
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return 0;
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}
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return 1;
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}
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static int
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xchacha20_poly1305_anycrypt_init(void *arg, void *initparams, enum aead_mode m)
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{
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struct lc_xchacha20_poly1305_params *params = initparams;
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struct chacha20_poly1305_state *state = arg;
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struct lc_xchacha20_params cparams;
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struct lc_poly1305_params aparams;
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size_t olen;
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if (params->cipher->impl != lc_cipher_impl_xchacha20() ||
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params->auth->impl != lc_auth_impl_poly1305())
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return 0;
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state->auth = params->auth;
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state->cipher = params->cipher;
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state->aadlen = state->ctlen = 0;
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state->aaddone = 0;
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memcpy(cparams.key, params->key, sizeof(params->key));
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memcpy(cparams.nonce, params->nonce, sizeof(params->nonce));
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cparams.counter = 0;
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if (!lc_cipher_encrypt(state->cipher->impl, aparams.key, &olen,
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&cparams, zerobuf, LC_POLY1305_KEYLEN))
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return 0;
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if (!lc_auth_init(state->auth, &aparams))
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return 0;
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cparams.counter = 1;
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switch (m) {
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case AEAD_SEAL:
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if (!lc_cipher_encrypt_init(state->cipher, &cparams))
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return 0;
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break;
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case AEAD_OPEN:
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if (!lc_cipher_decrypt_init(state->cipher, &cparams))
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return 0;
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break;
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default:
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return 0;
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}
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return 1;
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}
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static int
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c20_xc20_poly1305_anycrypt_update(void *arg, uint8_t *out, size_t *outlen,
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const uint8_t *aad, size_t aadlen, const uint8_t *in, size_t inlen,
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enum aead_mode m)
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{
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struct chacha20_poly1305_state *state = arg;
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size_t ctlen;
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*outlen = 0;
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switch (m) {
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case AEAD_SEAL:
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if (!lc_cipher_encrypt_update(state->cipher, NULL, &ctlen, in,
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inlen))
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return 0;
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break;
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case AEAD_OPEN:
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if (!lc_cipher_decrypt_update(state->cipher, NULL, &ctlen, in,
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inlen))
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return 0;
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break;
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default:
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if (!lc_cipher_decrypt_update(state->cipher, NULL, &ctlen, in,
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inlen))
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return 0;
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return 0;
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}
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if (aadlen > UINT64_MAX - state->aadlen ||
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ctlen > UINT64_MAX - state->ctlen)
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return 0;
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if (aadlen > 0 && state->aaddone)
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return 0;
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if (out == NULL) {
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*outlen = ctlen;
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return 1;
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}
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if (aadlen > 0) {
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if (!lc_auth_update(state->auth, aad, aadlen))
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return 0;
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state->aadlen += aadlen;
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}
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if (inlen > 0) {
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if (!state->aaddone) {
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if (state->aadlen % 16 != 0 &&
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!lc_auth_update(state->auth, zerobuf,
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16 - (state->aadlen % 16)))
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return 0;
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state->aaddone = 1;
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}
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switch (m) {
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case AEAD_SEAL:
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if (!lc_cipher_encrypt_update(state->cipher, out,
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outlen, in, inlen))
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return 0;
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if (!lc_auth_update(state->auth, out, *outlen))
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return 0;
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state->ctlen += *outlen;
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break;
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case AEAD_OPEN:
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if (!lc_auth_update(state->auth, in, inlen))
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return 0;
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if (!lc_cipher_decrypt_update(state->cipher, out,
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outlen, in, inlen))
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return 0;
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state->ctlen += inlen;
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break;
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default:
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return 0;
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}
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}
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return 1;
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}
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static int
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chacha20_poly1305_seal_init(void *arg, void *initparams)
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{
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return chacha20_poly1305_anycrypt_init(arg, initparams, AEAD_SEAL);
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}
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static int
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xchacha20_poly1305_seal_init(void *arg, void *initparams)
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{
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return xchacha20_poly1305_anycrypt_init(arg, initparams, AEAD_SEAL);
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}
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static int
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c20_xc20_poly1305_seal_update(void *arg, uint8_t *out, size_t *outlen,
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const uint8_t *aad, size_t aadlen, const uint8_t *in, size_t inlen)
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{
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return c20_xc20_poly1305_anycrypt_update(arg, out, outlen, aad, aadlen,
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in, inlen, AEAD_SEAL);
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}
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static int
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c20_xc20_poly1305_seal_final(void *arg, uint8_t *out, size_t *outlen,
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uint8_t *tag, size_t *taglen)
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{
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struct chacha20_poly1305_state *state = arg;
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uint8_t buf[sizeof(uint64_t) * 2];
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size_t ctlen;
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*outlen = *taglen = 0;
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if (!lc_cipher_encrypt_final(state->cipher, NULL, &ctlen))
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return 0;
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if (ctlen > UINT64_MAX - state->ctlen)
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return 0;
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if (out == NULL || tag == NULL) {
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*outlen = ctlen;
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*taglen = LC_POLY1305_TAGLEN;
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return 1;
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}
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if (!state->aaddone) {
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if (state->aadlen % 16 != 0 &&
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!lc_auth_update(state->auth, zerobuf,
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16 - (state->aadlen % 16)))
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return 0;
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state->aaddone = 1;
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}
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if (!lc_cipher_encrypt_final(state->cipher, out, outlen))
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return 0;
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if (!lc_auth_update(state->auth, out, *outlen))
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return 0;
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state->ctlen += *outlen;
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if (state->ctlen % 16 != 0 &&
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!lc_auth_update(state->auth, zerobuf, 16 - (state->ctlen % 16)))
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return 0;
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store64le(&buf[0], state->aadlen);
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store64le(&buf[sizeof(uint64_t)], state->ctlen);
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if (!lc_auth_update(state->auth, buf, sizeof(buf)) ||
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!lc_auth_final(state->auth, tag, taglen))
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return 0;
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return 1;
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}
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static int
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chacha20_poly1305_seal(uint8_t *out, size_t *outlen, uint8_t *tag,
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size_t *taglen, void *initparams, const uint8_t *aad, size_t aadlen,
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const uint8_t *in, size_t inlen)
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{
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struct chacha20_poly1305_state state;
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size_t olen;
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*outlen = *taglen = 0;
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/* inlen and aadlen are capped by design. */
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if (inlen > UINT64_MAX || aadlen > UINT64_MAX)
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return 0;
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/* Counter 0 is used for deriving Poly1305 key. */
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if (inlen > SIZE_MAX - (LC_CHACHA20_BLOCKLEN - 1) ||
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(inlen + LC_CHACHA20_BLOCKLEN - 1) / LC_CHACHA20_BLOCKLEN >
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CHACHA20_CTRMAX - 1)
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return 0;
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if (out == NULL || tag == NULL) {
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*outlen = inlen;
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*taglen = LC_POLY1305_TAGLEN;
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return 1;
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}
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if (!chacha20_poly1305_anycrypt_init(&state, initparams, AEAD_SEAL))
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return 0;
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if (!c20_xc20_poly1305_anycrypt_update(&state, out, &olen, aad, aadlen,
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in, inlen, AEAD_SEAL))
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return 0;
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*outlen = olen;
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if (!c20_xc20_poly1305_seal_final(&state, out + olen, &olen, tag,
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taglen))
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return 0;
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*outlen += olen;
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return 1;
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}
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static int
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xchacha20_poly1305_seal(uint8_t *out, size_t *outlen, uint8_t *tag,
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size_t *taglen, void *initparams, const uint8_t *aad, size_t aadlen,
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const uint8_t *in, size_t inlen)
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{
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struct chacha20_poly1305_state state;
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size_t olen;
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*outlen = *taglen = 0;
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/* inlen and aadlen are capped by design. */
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if (inlen > UINT64_MAX || aadlen > UINT64_MAX)
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return 0;
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/* Counter 0 is used for deriving Poly1305 key. */
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if (inlen > SIZE_MAX - (LC_CHACHA20_BLOCKLEN - 1) ||
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(inlen + LC_CHACHA20_BLOCKLEN - 1) / LC_CHACHA20_BLOCKLEN >
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CHACHA20_CTRMAX - 1)
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return 0;
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if (out == NULL || tag == NULL) {
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*outlen = inlen;
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*taglen = LC_POLY1305_TAGLEN;
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return 1;
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}
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if (!xchacha20_poly1305_anycrypt_init(&state, initparams, AEAD_SEAL))
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return 0;
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if (!c20_xc20_poly1305_anycrypt_update(&state, out, &olen, aad, aadlen,
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in, inlen, AEAD_SEAL))
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return 0;
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*outlen = olen;
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if (!c20_xc20_poly1305_seal_final(&state, out + olen, &olen, tag,
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taglen))
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return 0;
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*outlen += olen;
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return 1;
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}
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static int
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chacha20_poly1305_open_init(void *arg, void *initparams)
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{
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return chacha20_poly1305_anycrypt_init(arg, initparams, AEAD_OPEN);
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}
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static int
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xchacha20_poly1305_open_init(void *arg, void *initparams)
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{
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return xchacha20_poly1305_anycrypt_init(arg, initparams, AEAD_OPEN);
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}
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static int
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c20_xc20_poly1305_open_update(void *arg, uint8_t *out, size_t *outlen,
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const uint8_t *aad, size_t aadlen, const uint8_t *in, size_t inlen)
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{
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return c20_xc20_poly1305_anycrypt_update(arg, out, outlen, aad, aadlen,
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in, inlen, AEAD_OPEN);
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}
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static int
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c20_xc20_poly1305_open_final(void *arg, uint8_t *out, size_t *outlen,
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const uint8_t *tag, size_t taglen)
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{
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struct chacha20_poly1305_state *state = arg;
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uint8_t buf[sizeof(uint64_t) * 2],
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ctag[LC_POLY1305_TAGLEN];
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size_t ctlen, ctaglen;
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*outlen = 0;
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if (!lc_cipher_decrypt_final(state->cipher, NULL, &ctlen))
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return 0;
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if (ctlen > UINT64_MAX - state->ctlen ||
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taglen != LC_POLY1305_TAGLEN)
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return 0;
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if (out == NULL) {
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*outlen = ctlen;
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return 1;
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}
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if (!state->aaddone) {
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if (state->aadlen % 16 != 0 &&
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!lc_auth_update(state->auth, zerobuf,
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16 - (state->aadlen % 16)))
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return 0;
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state->aaddone = 1;
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}
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if (state->ctlen % 16 != 0 &&
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!lc_auth_update(state->auth, zerobuf, 16 - (state->ctlen % 16)))
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return 0;
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store64le(&buf[0], state->aadlen);
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store64le(&buf[sizeof(uint64_t)], state->ctlen);
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if (!lc_auth_update(state->auth, buf, sizeof(buf)) ||
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!lc_auth_final(state->auth, ctag, &ctaglen))
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return 0;
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if (!lc_ct_cmp(ctag, tag, LC_POLY1305_TAGLEN))
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return 0;
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return lc_cipher_decrypt_final(state->cipher, out, outlen);
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}
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static int
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chacha20_poly1305_open(uint8_t *out, size_t *outlen, void *initparams,
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const uint8_t *tag, size_t taglen, const uint8_t *aad, size_t aadlen,
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const uint8_t *in, size_t inlen)
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{
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struct chacha20_poly1305_state state;
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size_t olen;
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*outlen = 0;
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/* inlen and aadlen are capped by design. */
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if (inlen > UINT64_MAX || aadlen > UINT64_MAX)
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return 0;
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/* Counter 0 is used for deriving Poly1305 key. */
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if (inlen > SIZE_MAX - (LC_CHACHA20_BLOCKLEN - 1) ||
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(inlen + LC_CHACHA20_BLOCKLEN - 1) / LC_CHACHA20_BLOCKLEN >
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CHACHA20_CTRMAX - 1)
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return 0;
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if (out == NULL) {
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*outlen = inlen;
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return 1;
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}
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if (!chacha20_poly1305_anycrypt_init(&state, initparams, AEAD_OPEN))
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return 0;
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if (!c20_xc20_poly1305_anycrypt_update(&state, out, &olen, aad, aadlen,
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in, inlen, AEAD_OPEN))
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return 0;
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*outlen = olen;
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if (!c20_xc20_poly1305_open_final(&state, out + olen, &olen, tag,
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taglen))
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return 0;
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*outlen += olen;
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return 1;
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}
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static int
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xchacha20_poly1305_open(uint8_t *out, size_t *outlen, void *initparams,
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const uint8_t *tag, size_t taglen, const uint8_t *aad, size_t aadlen,
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const uint8_t *in, size_t inlen)
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{
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struct chacha20_poly1305_state state;
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size_t olen;
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*outlen = 0;
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/* inlen and aadlen are capped by design. */
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if (inlen > UINT64_MAX || aadlen > UINT64_MAX)
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return 0;
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/* Counter 0 is used for deriving Poly1305 key. */
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if (inlen > SIZE_MAX - (LC_CHACHA20_BLOCKLEN - 1) ||
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(inlen + LC_CHACHA20_BLOCKLEN - 1) / LC_CHACHA20_BLOCKLEN >
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CHACHA20_CTRMAX - 1)
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return 0;
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if (out == NULL) {
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*outlen = inlen;
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return 1;
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}
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if (!xchacha20_poly1305_anycrypt_init(&state, initparams, AEAD_OPEN))
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return 0;
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if (!c20_xc20_poly1305_anycrypt_update(&state, out, &olen, aad, aadlen,
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in, inlen, AEAD_OPEN))
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return 0;
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*outlen = olen;
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if (!c20_xc20_poly1305_open_final(&state, out + olen, &olen, tag,
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taglen))
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return 0;
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*outlen += olen;
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return 1;
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}
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const struct lc_aead_impl *
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lc_aead_impl_chacha20_poly1305(void)
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{
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static struct lc_aead_impl chacha20_poly1305_impl = {
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.seal_init = &chacha20_poly1305_seal_init,
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.seal_update = &c20_xc20_poly1305_seal_update,
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.seal_final = &c20_xc20_poly1305_seal_final,
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.seal = &chacha20_poly1305_seal,
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|
.open_init = &chacha20_poly1305_open_init,
|
|
.open_update = &c20_xc20_poly1305_open_update,
|
|
.open_final = &c20_xc20_poly1305_open_final,
|
|
.open = &chacha20_poly1305_open,
|
|
|
|
.argsz = sizeof(struct chacha20_poly1305_state),
|
|
.blocklen = LC_CHACHA20_BLOCKLEN,
|
|
};
|
|
|
|
return &chacha20_poly1305_impl;
|
|
}
|
|
|
|
const struct lc_aead_impl *
|
|
lc_aead_impl_xchacha20_poly1305(void)
|
|
{
|
|
static struct lc_aead_impl xchacha20_poly1305_impl = {
|
|
.seal_init = &xchacha20_poly1305_seal_init,
|
|
.seal_update = &c20_xc20_poly1305_seal_update,
|
|
.seal_final = &c20_xc20_poly1305_seal_final,
|
|
.seal = &xchacha20_poly1305_seal,
|
|
|
|
.open_init = &xchacha20_poly1305_open_init,
|
|
.open_update = &c20_xc20_poly1305_open_update,
|
|
.open_final = &c20_xc20_poly1305_open_final,
|
|
.open = &xchacha20_poly1305_open,
|
|
|
|
.argsz = sizeof(struct chacha20_poly1305_state),
|
|
.blocklen = LC_CHACHA20_BLOCKLEN,
|
|
};
|
|
|
|
return &xchacha20_poly1305_impl;
|
|
}
|