static int aead_aes_gcm_tls12_seal_scatter(
const EVP_AEAD_CTX *ctx, uint8_t *out, uint8_t *out_tag,
size_t *out_tag_len, size_t max_out_tag_len, const uint8_t *nonce,
size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *extra_in,
size_t extra_in_len, const uint8_t *ad, size_t ad_len) {
struct aead_aes_gcm_tls12_ctx *gcm_ctx = ctx->aead_state;
if (nonce_len != 12) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}
// The given nonces must be strictly monotonically increasing.
uint64_t given_counter;
OPENSSL_memcpy(&given_counter, nonce + nonce_len - sizeof(given_counter),
sizeof(given_counter));
given_counter = CRYPTO_bswap8(given_counter);
if (given_counter == UINT64_MAX ||
given_counter < gcm_ctx->min_next_nonce) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE);
return 0;
}
gcm_ctx->min_next_nonce = given_counter + 1;
return aead_aes_gcm_seal_scatter(ctx, out, out_tag, out_tag_len,
max_out_tag_len, nonce, nonce_len, in,
in_len, extra_in, extra_in_len, ad, ad_len);
}
static int aead_aes_gcm_tls13_seal_scatter(
const EVP_AEAD_CTX *ctx, uint8_t *out, uint8_t *out_tag,
size_t *out_tag_len, size_t max_out_tag_len, const uint8_t *nonce,
size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *extra_in,
size_t extra_in_len, const uint8_t *ad, size_t ad_len) {
struct aead_aes_gcm_tls13_ctx *gcm_ctx =
(struct aead_aes_gcm_tls13_ctx *) &ctx->state;
if (nonce_len != 12) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}
// The given nonces must be strictly monotonically increasing. See
// https://tools.ietf.org/html/rfc8446#section-5.3 for details of the TLS 1.3
// nonce construction.
uint64_t given_counter;
OPENSSL_memcpy(&given_counter, nonce + nonce_len - sizeof(given_counter),
sizeof(given_counter));
given_counter = CRYPTO_bswap8(given_counter);
if (gcm_ctx->first) {
// In the first call the sequence number will be zero and therefore the
// given nonce will be 0 ^ mask = mask.
gcm_ctx->mask = given_counter;
gcm_ctx->first = 0;
}
given_counter ^= gcm_ctx->mask;
if (given_counter == UINT64_MAX ||
given_counter < gcm_ctx->min_next_nonce) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_NONCE);
return 0;
}
gcm_ctx->min_next_nonce = given_counter + 1;
return aead_aes_gcm_seal_scatter(ctx, out, out_tag, out_tag_len,
max_out_tag_len, nonce, nonce_len, in,
in_len, extra_in, extra_in_len, ad, ad_len);
}
