int EVP_AEAD_CTX_init(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead,
const uint8_t *key, size_t key_len, size_t tag_len,
ENGINE *impl) {
if (!aead->init) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_NO_DIRECTION_SET);
ctx->aead = NULL;
return 0;
}
return EVP_AEAD_CTX_init_with_direction(ctx, aead, key, key_len, tag_len,
evp_aead_open);
}
SSL_AEAD_CTX *SSL_AEAD_CTX_new(enum evp_aead_direction_t direction,
uint16_t version, const SSL_CIPHER *cipher,
const uint8_t *enc_key, size_t enc_key_len,
const uint8_t *mac_key, size_t mac_key_len,
const uint8_t *fixed_iv, size_t fixed_iv_len) {
const EVP_AEAD *aead;
size_t discard;
if (!ssl_cipher_get_evp_aead(&aead, &discard, &discard, cipher, version)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH];
if (mac_key_len > 0) {
/* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher
* suites). */
if (mac_key_len + enc_key_len + fixed_iv_len > sizeof(merged_key)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(merged_key, mac_key, mac_key_len);
memcpy(merged_key + mac_key_len, enc_key, enc_key_len);
memcpy(merged_key + mac_key_len + enc_key_len, fixed_iv, fixed_iv_len);
enc_key = merged_key;
enc_key_len += mac_key_len;
enc_key_len += fixed_iv_len;
}
SSL_AEAD_CTX *aead_ctx = OPENSSL_malloc(sizeof(SSL_AEAD_CTX));
if (aead_ctx == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return NULL;
}
memset(aead_ctx, 0, sizeof(SSL_AEAD_CTX));
aead_ctx->cipher = cipher;
if (!EVP_AEAD_CTX_init_with_direction(
&aead_ctx->ctx, aead, enc_key, enc_key_len,
EVP_AEAD_DEFAULT_TAG_LENGTH, direction)) {
OPENSSL_free(aead_ctx);
return NULL;
}
assert(EVP_AEAD_nonce_length(aead) <= EVP_AEAD_MAX_NONCE_LENGTH);
aead_ctx->variable_nonce_len = (uint8_t)EVP_AEAD_nonce_length(aead);
if (mac_key_len == 0) {
assert(fixed_iv_len <= sizeof(aead_ctx->fixed_nonce));
memcpy(aead_ctx->fixed_nonce, fixed_iv, fixed_iv_len);
aead_ctx->fixed_nonce_len = fixed_iv_len;
if (cipher->algorithm_enc & SSL_CHACHA20POLY1305) {
/* The fixed nonce into the actual nonce (the sequence number). */
aead_ctx->xor_fixed_nonce = 1;
aead_ctx->variable_nonce_len = 8;
} else {
/* The fixed IV is prepended to the nonce. */
assert(fixed_iv_len <= aead_ctx->variable_nonce_len);
aead_ctx->variable_nonce_len -= fixed_iv_len;
}
/* AES-GCM uses an explicit nonce. */
if (cipher->algorithm_enc & (SSL_AES128GCM | SSL_AES256GCM)) {
aead_ctx->variable_nonce_included_in_record = 1;
}
/* The TLS 1.3 construction XORs the fixed nonce into the sequence number
* and omits the additional data. */
if (version >= TLS1_3_VERSION) {
aead_ctx->xor_fixed_nonce = 1;
aead_ctx->variable_nonce_len = 8;
aead_ctx->variable_nonce_included_in_record = 0;
aead_ctx->omit_ad = 1;
}
} else {
aead_ctx->variable_nonce_included_in_record = 1;
aead_ctx->random_variable_nonce = 1;
aead_ctx->omit_length_in_ad = 1;
aead_ctx->omit_version_in_ad = (version == SSL3_VERSION);
}
return aead_ctx;
}
SSL_AEAD_CTX *SSL_AEAD_CTX_new(enum evp_aead_direction_t direction,
uint16_t version, const SSL_CIPHER *cipher,
const uint8_t *enc_key, size_t enc_key_len,
const uint8_t *mac_key, size_t mac_key_len,
const uint8_t *fixed_iv, size_t fixed_iv_len) {
const EVP_AEAD *aead;
size_t discard;
if (!ssl_cipher_get_evp_aead(&aead, &discard, &discard, cipher, version)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH];
if (mac_key_len > 0) {
/* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher
* suites). */
if (mac_key_len + enc_key_len + fixed_iv_len > sizeof(merged_key)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(merged_key, mac_key, mac_key_len);
memcpy(merged_key + mac_key_len, enc_key, enc_key_len);
memcpy(merged_key + mac_key_len + enc_key_len, fixed_iv, fixed_iv_len);
enc_key = merged_key;
enc_key_len += mac_key_len;
enc_key_len += fixed_iv_len;
}
SSL_AEAD_CTX *aead_ctx = (SSL_AEAD_CTX *)OPENSSL_malloc(sizeof(SSL_AEAD_CTX));
if (aead_ctx == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return NULL;
}
memset(aead_ctx, 0, sizeof(SSL_AEAD_CTX));
aead_ctx->cipher = cipher;
if (!EVP_AEAD_CTX_init_with_direction(
&aead_ctx->ctx, aead, enc_key, enc_key_len,
EVP_AEAD_DEFAULT_TAG_LENGTH, direction)) {
OPENSSL_free(aead_ctx);
return NULL;
}
assert(EVP_AEAD_nonce_length(aead) <= EVP_AEAD_MAX_NONCE_LENGTH);
aead_ctx->variable_nonce_len = (uint8_t)EVP_AEAD_nonce_length(aead);
if (mac_key_len == 0) {
/* For a real AEAD, the IV is the fixed part of the nonce. */
if (fixed_iv_len > sizeof(aead_ctx->fixed_nonce) ||
fixed_iv_len > aead_ctx->variable_nonce_len) {
SSL_AEAD_CTX_free(aead_ctx);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
aead_ctx->variable_nonce_len -= fixed_iv_len;
memcpy(aead_ctx->fixed_nonce, fixed_iv, fixed_iv_len);
aead_ctx->fixed_nonce_len = fixed_iv_len;
/* AES-GCM uses an explicit nonce. */
if (cipher->algorithm_enc & (SSL_AES128GCM | SSL_AES256GCM)) {
aead_ctx->variable_nonce_included_in_record = 1;
}
} else {
aead_ctx->variable_nonce_included_in_record = 1;
aead_ctx->random_variable_nonce = 1;
aead_ctx->omit_length_in_ad = 1;
aead_ctx->omit_version_in_ad = (version == SSL3_VERSION);
}
return aead_ctx;
}
static int tls1_change_cipher_state_aead(SSL *s, char is_read,
const uint8_t *key, unsigned key_len,
const uint8_t *iv, unsigned iv_len,
const uint8_t *mac_secret,
unsigned mac_secret_len) {
const EVP_AEAD *aead = s->s3->tmp.new_aead;
SSL_AEAD_CTX *aead_ctx;
/* merged_key is used to merge the MAC, cipher, and IV keys for an AEAD which
* simulates pre-AEAD cipher suites. */
uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH];
if (mac_secret_len > 0) {
/* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher
* suites). */
if (mac_secret_len + key_len + iv_len > sizeof(merged_key)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead,
ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(merged_key, mac_secret, mac_secret_len);
memcpy(merged_key + mac_secret_len, key, key_len);
memcpy(merged_key + mac_secret_len + key_len, iv, iv_len);
key = merged_key;
key_len += mac_secret_len;
key_len += iv_len;
}
if (is_read) {
if (!tls1_aead_ctx_init(&s->aead_read_ctx)) {
return 0;
}
aead_ctx = s->aead_read_ctx;
} else {
if (SSL_IS_DTLS(s) && s->aead_write_ctx != NULL) {
/* DTLS renegotiation is unsupported, so a CCS can only switch away from
* the NULL cipher. This simplifies renegotiation. */
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead,
ERR_R_INTERNAL_ERROR);
return 0;
}
if (!tls1_aead_ctx_init(&s->aead_write_ctx)) {
return 0;
}
aead_ctx = s->aead_write_ctx;
}
if (!EVP_AEAD_CTX_init_with_direction(
&aead_ctx->ctx, aead, key, key_len, EVP_AEAD_DEFAULT_TAG_LENGTH,
is_read ? evp_aead_open : evp_aead_seal)) {
OPENSSL_free(aead_ctx);
if (is_read) {
s->aead_read_ctx = NULL;
} else {
s->aead_write_ctx = NULL;
}
return 0;
}
if (mac_secret_len == 0) {
/* For a real AEAD, the IV is the fixed part of the nonce. */
if (iv_len > sizeof(aead_ctx->fixed_nonce)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
return 0;
}
memcpy(aead_ctx->fixed_nonce, iv, iv_len);
aead_ctx->fixed_nonce_len = iv_len;
aead_ctx->variable_nonce_included_in_record =
(s->s3->tmp.new_cipher->algorithm2 &
SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_INCLUDED_IN_RECORD) != 0;
aead_ctx->random_variable_nonce = 0;
aead_ctx->omit_length_in_ad = 0;
} else {
aead_ctx->fixed_nonce_len = 0;
aead_ctx->variable_nonce_included_in_record = 1;
aead_ctx->random_variable_nonce = 1;
aead_ctx->omit_length_in_ad = 1;
}
aead_ctx->variable_nonce_len = s->s3->tmp.new_variable_iv_len;
aead_ctx->omit_version_in_ad = (s->version == SSL3_VERSION);
if (aead_ctx->variable_nonce_len + aead_ctx->fixed_nonce_len !=
EVP_AEAD_nonce_length(aead)) {
OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
return 0;
}
aead_ctx->tag_len = EVP_AEAD_max_overhead(aead);
return 1;
}
