/*-
* tls13_enc encrypts/decrypts |n_recs| in |recs|.
*
* Returns:
* 0: (in non-constant time) if the record is publically invalid (i.e. too
* short etc).
* 1: if the record encryption was successful.
* -1: if the record's AEAD-authenticator is invalid or, if sending,
* an internal error occurred.
*/
int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
{
EVP_CIPHER_CTX *ctx;
unsigned char iv[EVP_MAX_IV_LENGTH];
size_t ivlen, taglen, offset, loop;
unsigned char *staticiv;
unsigned char *seq;
int lenu, lenf;
SSL3_RECORD *rec = &recs[0];
uint32_t alg_enc;
if (n_recs != 1) {
/* Should not happen */
/* TODO(TLS1.3): Support pipelining */
return -1;
}
if (sending) {
ctx = s->enc_write_ctx;
staticiv = s->write_iv;
seq = RECORD_LAYER_get_write_sequence(&s->rlayer);
} else {
ctx = s->enc_read_ctx;
staticiv = s->read_iv;
seq = RECORD_LAYER_get_read_sequence(&s->rlayer);
}
if (ctx == NULL) {
memmove(rec->data, rec->input, rec->length);
rec->input = rec->data;
return 1;
}
ivlen = EVP_CIPHER_CTX_iv_length(ctx);
if (s->early_data_state == SSL_EARLY_DATA_WRITING
|| s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
alg_enc = s->session->cipher->algorithm_enc;
} else {
/*
* To get here we must have selected a ciphersuite - otherwise ctx would
* be NULL
*/
assert(s->s3->tmp.new_cipher != NULL);
if (s->s3->tmp.new_cipher == NULL)
return -1;
alg_enc = s->s3->tmp.new_cipher->algorithm_enc;
}
if (alg_enc & SSL_AESCCM) {
if (alg_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
taglen = EVP_CCM8_TLS_TAG_LEN;
else
taglen = EVP_CCM_TLS_TAG_LEN;
if (sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
NULL) <= 0)
return -1;
} else if (alg_enc & SSL_AESGCM) {
taglen = EVP_GCM_TLS_TAG_LEN;
} else if (alg_enc & SSL_CHACHA20) {
taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
} else {
return -1;
}
if (!sending) {
/*
* Take off tag. There must be at least one byte of content type as
* well as the tag
*/
if (rec->length < taglen + 1)
return 0;
rec->length -= taglen;
}
/* Set up IV */
if (ivlen < SEQ_NUM_SIZE) {
/* Should not happen */
return -1;
}
offset = ivlen - SEQ_NUM_SIZE;
memcpy(iv, staticiv, offset);
for (loop = 0; loop < SEQ_NUM_SIZE; loop++)
iv[offset + loop] = staticiv[offset + loop] ^ seq[loop];
/* Increment the sequence counter */
for (loop = SEQ_NUM_SIZE; loop > 0; loop--) {
++seq[loop - 1];
if (seq[loop - 1] != 0)
break;
}
if (loop == 0) {
/* Sequence has wrapped */
return -1;
}
/* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, sending) <= 0
|| (!sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
taglen,
rec->data + rec->length) <= 0)
|| EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
(unsigned int)rec->length) <= 0
|| EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
|| (size_t)(lenu + lenf) != rec->length) {
return -1;
}
if (sending) {
/* Add the tag */
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
rec->data + rec->length) <= 0)
return -1;
rec->length += taglen;
}
return 1;
}
static int test_tls13_encryption(void)
{
SSL_CTX *ctx = NULL;
SSL *s = NULL;
SSL3_RECORD rec;
unsigned char *key = NULL, *iv = NULL, *seq = NULL;
const EVP_CIPHER *ciph = EVP_aes_128_gcm();
int ret = 0;
size_t ivlen, ctr;
/*
* Encrypted TLSv1.3 records always have an outer content type of
* application data, and a record version of TLSv1.2.
*/
rec.data = NULL;
rec.type = SSL3_RT_APPLICATION_DATA;
rec.rec_version = TLS1_2_VERSION;
ctx = SSL_CTX_new(TLS_method());
if (!TEST_ptr(ctx)) {
TEST_info("Failed creating SSL_CTX");
goto err;
}
s = SSL_new(ctx);
if (!TEST_ptr(s)) {
TEST_info("Failed creating SSL");
goto err;
}
s->enc_read_ctx = EVP_CIPHER_CTX_new();
if (!TEST_ptr(s->enc_read_ctx))
goto err;
s->enc_write_ctx = EVP_CIPHER_CTX_new();
if (!TEST_ptr(s->enc_write_ctx))
goto err;
s->s3->tmp.new_cipher = SSL_CIPHER_find(s, TLS13_AES_128_GCM_SHA256_BYTES);
if (!TEST_ptr(s->s3->tmp.new_cipher)) {
TEST_info("Failed to find cipher");
goto err;
}
for (ctr = 0; ctr < OSSL_NELEM(refdata); ctr++) {
/* Load the record */
ivlen = EVP_CIPHER_iv_length(ciph);
if (!load_record(&rec, &refdata[ctr], &key, s->read_iv, ivlen,
RECORD_LAYER_get_read_sequence(&s->rlayer))) {
TEST_error("Failed loading key into EVP_CIPHER_CTX");
goto err;
}
/* Set up the read/write sequences */
memcpy(RECORD_LAYER_get_write_sequence(&s->rlayer),
RECORD_LAYER_get_read_sequence(&s->rlayer), SEQ_NUM_SIZE);
memcpy(s->write_iv, s->read_iv, ivlen);
/* Load the key into the EVP_CIPHER_CTXs */
if (EVP_CipherInit_ex(s->enc_write_ctx, ciph, NULL, key, NULL, 1) <= 0
|| EVP_CipherInit_ex(s->enc_read_ctx, ciph, NULL, key, NULL, 0)
<= 0) {
TEST_error("Failed loading key into EVP_CIPHER_CTX\n");
goto err;
}
/* Encrypt it */
if (!TEST_size_t_eq(tls13_enc(s, &rec, 1, 1), 1)) {
TEST_info("Failed to encrypt record %zu", ctr);
goto err;
}
if (!TEST_true(test_record(&rec, &refdata[ctr], 1))) {
TEST_info("Record %zu encryption test failed", ctr);
goto err;
}
/* Decrypt it */
if (!TEST_int_eq(tls13_enc(s, &rec, 1, 0), 1)) {
TEST_info("Failed to decrypt record %zu", ctr);
goto err;
}
if (!TEST_true(test_record(&rec, &refdata[ctr], 0))) {
TEST_info("Record %zu decryption test failed", ctr);
goto err;
}
OPENSSL_free(rec.data);
OPENSSL_free(key);
OPENSSL_free(iv);
OPENSSL_free(seq);
rec.data = NULL;
key = NULL;
iv = NULL;
seq = NULL;
}
TEST_note("PASS: %zu records tested", ctr);
ret = 1;
err:
OPENSSL_free(rec.data);
OPENSSL_free(key);
OPENSSL_free(iv);
OPENSSL_free(seq);
SSL_free(s);
SSL_CTX_free(ctx);
return ret;
}
/*-
* tls13_enc encrypts/decrypts |n_recs| in |recs|. Will call SSLfatal() for
* internal errors, but not otherwise.
*
* Returns:
* 0: (in non-constant time) if the record is publically invalid (i.e. too
* short etc).
* 1: if the record encryption was successful.
* -1: if the record's AEAD-authenticator is invalid or, if sending,
* an internal error occurred.
*/
int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
{
EVP_CIPHER_CTX *ctx;
unsigned char iv[EVP_MAX_IV_LENGTH], recheader[SSL3_RT_HEADER_LENGTH];
size_t ivlen, taglen, offset, loop, hdrlen;
unsigned char *staticiv;
unsigned char *seq;
int lenu, lenf;
SSL3_RECORD *rec = &recs[0];
uint32_t alg_enc;
WPACKET wpkt;
if (n_recs != 1) {
/* Should not happen */
/* TODO(TLS1.3): Support pipelining */
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
if (sending) {
ctx = s->enc_write_ctx;
staticiv = s->write_iv;
seq = RECORD_LAYER_get_write_sequence(&s->rlayer);
} else {
ctx = s->enc_read_ctx;
staticiv = s->read_iv;
seq = RECORD_LAYER_get_read_sequence(&s->rlayer);
}
/*
* If we're sending an alert and ctx != NULL then we must be forcing
* plaintext alerts. If we're reading and ctx != NULL then we allow
* plaintext alerts at certain points in the handshake. If we've got this
* far then we have already validated that a plaintext alert is ok here.
*/
if (ctx == NULL || rec->type == SSL3_RT_ALERT) {
memmove(rec->data, rec->input, rec->length);
rec->input = rec->data;
return 1;
}
ivlen = EVP_CIPHER_CTX_iv_length(ctx);
if (s->early_data_state == SSL_EARLY_DATA_WRITING
|| s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
if (s->session != NULL && s->session->ext.max_early_data > 0) {
alg_enc = s->session->cipher->algorithm_enc;
} else {
if (!ossl_assert(s->psksession != NULL
&& s->psksession->ext.max_early_data > 0)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
alg_enc = s->psksession->cipher->algorithm_enc;
}
} else {
/*
* To get here we must have selected a ciphersuite - otherwise ctx would
* be NULL
*/
if (!ossl_assert(s->s3->tmp.new_cipher != NULL)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
alg_enc = s->s3->tmp.new_cipher->algorithm_enc;
}
if (alg_enc & SSL_AESCCM) {
if (alg_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
taglen = EVP_CCM8_TLS_TAG_LEN;
else
taglen = EVP_CCM_TLS_TAG_LEN;
if (sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
NULL) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
} else if (alg_enc & SSL_AESGCM) {
taglen = EVP_GCM_TLS_TAG_LEN;
} else if (alg_enc & SSL_CHACHA20) {
taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
} else {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
if (!sending) {
/*
* Take off tag. There must be at least one byte of content type as
* well as the tag
*/
if (rec->length < taglen + 1)
return 0;
rec->length -= taglen;
}
/* Set up IV */
if (ivlen < SEQ_NUM_SIZE) {
/* Should not happen */
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
offset = ivlen - SEQ_NUM_SIZE;
memcpy(iv, staticiv, offset);
for (loop = 0; loop < SEQ_NUM_SIZE; loop++)
iv[offset + loop] = staticiv[offset + loop] ^ seq[loop];
/* Increment the sequence counter */
for (loop = SEQ_NUM_SIZE; loop > 0; loop--) {
++seq[loop - 1];
if (seq[loop - 1] != 0)
break;
}
if (loop == 0) {
/* Sequence has wrapped */
return -1;
}
/* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, sending) <= 0
|| (!sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
taglen,
rec->data + rec->length) <= 0)) {
return -1;
}
/* Set up the AAD */
if (!WPACKET_init_static_len(&wpkt, recheader, sizeof(recheader), 0)
|| !WPACKET_put_bytes_u8(&wpkt, rec->type)
|| !WPACKET_put_bytes_u16(&wpkt, rec->rec_version)
|| !WPACKET_put_bytes_u16(&wpkt, rec->length + taglen)
|| !WPACKET_get_total_written(&wpkt, &hdrlen)
|| hdrlen != SSL3_RT_HEADER_LENGTH
|| !WPACKET_finish(&wpkt)) {
WPACKET_cleanup(&wpkt);
return -1;
}
/*
* For CCM we must explicitly set the total plaintext length before we add
* any AAD.
*/
if (((alg_enc & SSL_AESCCM) != 0
&& EVP_CipherUpdate(ctx, NULL, &lenu, NULL,
(unsigned int)rec->length) <= 0)
|| EVP_CipherUpdate(ctx, NULL, &lenu, recheader,
sizeof(recheader)) <= 0
|| EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
(unsigned int)rec->length) <= 0
|| EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
|| (size_t)(lenu + lenf) != rec->length) {
return -1;
}
if (sending) {
/* Add the tag */
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
rec->data + rec->length) <= 0) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
ERR_R_INTERNAL_ERROR);
return -1;
}
rec->length += taglen;
}
return 1;
}
