2 * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "../ssl_locl.h"
11 #include "record_locl.h"
12 #include "internal/cryptlib.h"
15 * tls13_enc encrypts/decrypts |n_recs| in |recs|. Will call SSLfatal() for
16 * internal errors, but not otherwise.
19 * 0: (in non-constant time) if the record is publically invalid (i.e. too
21 * 1: if the record encryption was successful.
22 * -1: if the record's AEAD-authenticator is invalid or, if sending,
23 * an internal error occurred.
25 int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
28 unsigned char iv[EVP_MAX_IV_LENGTH], recheader[SSL3_RT_HEADER_LENGTH];
29 size_t ivlen, taglen, offset, loop, hdrlen;
30 unsigned char *staticiv;
33 SSL3_RECORD *rec = &recs[0];
38 /* Should not happen */
39 /* TODO(TLS1.3): Support pipelining */
40 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
41 ERR_R_INTERNAL_ERROR);
46 ctx = s->enc_write_ctx;
47 staticiv = s->write_iv;
48 seq = RECORD_LAYER_get_write_sequence(&s->rlayer);
50 ctx = s->enc_read_ctx;
51 staticiv = s->read_iv;
52 seq = RECORD_LAYER_get_read_sequence(&s->rlayer);
56 * If we're sending an alert and ctx != NULL then we must be forcing
57 * plaintext alerts. If we're reading and ctx != NULL then we allow
58 * plaintext alerts at certain points in the handshake. If we've got this
59 * far then we have already validated that a plaintext alert is ok here.
61 if (ctx == NULL || rec->type == SSL3_RT_ALERT) {
62 memmove(rec->data, rec->input, rec->length);
63 rec->input = rec->data;
67 ivlen = EVP_CIPHER_CTX_iv_length(ctx);
69 if (s->early_data_state == SSL_EARLY_DATA_WRITING
70 || s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
71 if (s->session != NULL && s->session->ext.max_early_data > 0) {
72 alg_enc = s->session->cipher->algorithm_enc;
74 if (!ossl_assert(s->psksession != NULL
75 && s->psksession->ext.max_early_data > 0)) {
76 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
77 ERR_R_INTERNAL_ERROR);
80 alg_enc = s->psksession->cipher->algorithm_enc;
84 * To get here we must have selected a ciphersuite - otherwise ctx would
87 if (!ossl_assert(s->s3->tmp.new_cipher != NULL)) {
88 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
89 ERR_R_INTERNAL_ERROR);
92 alg_enc = s->s3->tmp.new_cipher->algorithm_enc;
95 if (alg_enc & SSL_AESCCM) {
96 if (alg_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
97 taglen = EVP_CCM8_TLS_TAG_LEN;
99 taglen = EVP_CCM_TLS_TAG_LEN;
100 if (sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
102 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
103 ERR_R_INTERNAL_ERROR);
106 } else if (alg_enc & SSL_AESGCM) {
107 taglen = EVP_GCM_TLS_TAG_LEN;
108 } else if (alg_enc & SSL_CHACHA20) {
109 taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
111 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
112 ERR_R_INTERNAL_ERROR);
118 * Take off tag. There must be at least one byte of content type as
121 if (rec->length < taglen + 1)
123 rec->length -= taglen;
127 if (ivlen < SEQ_NUM_SIZE) {
128 /* Should not happen */
129 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
130 ERR_R_INTERNAL_ERROR);
133 offset = ivlen - SEQ_NUM_SIZE;
134 memcpy(iv, staticiv, offset);
135 for (loop = 0; loop < SEQ_NUM_SIZE; loop++)
136 iv[offset + loop] = staticiv[offset + loop] ^ seq[loop];
138 /* Increment the sequence counter */
139 for (loop = SEQ_NUM_SIZE; loop > 0; loop--) {
141 if (seq[loop - 1] != 0)
145 /* Sequence has wrapped */
149 /* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
150 if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, sending) <= 0
151 || (!sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
153 rec->data + rec->length) <= 0)) {
158 if (!WPACKET_init_static_len(&wpkt, recheader, sizeof(recheader), 0)
159 || !WPACKET_put_bytes_u8(&wpkt, rec->type)
160 || !WPACKET_put_bytes_u16(&wpkt, rec->rec_version)
161 || !WPACKET_put_bytes_u16(&wpkt, rec->length + taglen)
162 || !WPACKET_get_total_written(&wpkt, &hdrlen)
163 || hdrlen != SSL3_RT_HEADER_LENGTH
164 || !WPACKET_finish(&wpkt)) {
165 WPACKET_cleanup(&wpkt);
170 * For CCM we must explicitly set the total plaintext length before we add
173 if (((alg_enc & SSL_AESCCM) != 0
174 && EVP_CipherUpdate(ctx, NULL, &lenu, NULL,
175 (unsigned int)rec->length) <= 0)
176 || EVP_CipherUpdate(ctx, NULL, &lenu, recheader,
177 sizeof(recheader)) <= 0
178 || EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
179 (unsigned int)rec->length) <= 0
180 || EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
181 || (size_t)(lenu + lenf) != rec->length) {
186 if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
187 rec->data + rec->length) <= 0) {
188 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
189 ERR_R_INTERNAL_ERROR);
192 rec->length += taglen;