2 * Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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_local.h"
11 #include "record_local.h"
12 #include "internal/cryptlib.h"
15 * tls13_enc encrypts/decrypts |n_recs| in |recs|. Calls SSLfatal on internal
16 * error, but not otherwise. It is the responsibility of the caller to report
21 * 1: if the record encryption/decryption was successful.
23 int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending,
24 SSL_MAC_BUF *mac, size_t macsize)
27 unsigned char iv[EVP_MAX_IV_LENGTH], recheader[SSL3_RT_HEADER_LENGTH];
28 size_t ivlen, taglen, offset, loop, hdrlen;
29 unsigned char *staticiv;
32 SSL3_RECORD *rec = &recs[0];
37 /* Should not happen */
38 /* TODO(TLS1.3): Support pipelining */
39 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
40 ERR_R_INTERNAL_ERROR);
45 ctx = s->enc_write_ctx;
46 staticiv = s->write_iv;
47 seq = RECORD_LAYER_get_write_sequence(&s->rlayer);
49 ctx = s->enc_read_ctx;
50 staticiv = s->read_iv;
51 seq = RECORD_LAYER_get_read_sequence(&s->rlayer);
55 * If we're sending an alert and ctx != NULL then we must be forcing
56 * plaintext alerts. If we're reading and ctx != NULL then we allow
57 * plaintext alerts at certain points in the handshake. If we've got this
58 * far then we have already validated that a plaintext alert is ok here.
60 if (ctx == NULL || rec->type == SSL3_RT_ALERT) {
61 memmove(rec->data, rec->input, rec->length);
62 rec->input = rec->data;
66 ivlen = EVP_CIPHER_CTX_iv_length(ctx);
68 if (s->early_data_state == SSL_EARLY_DATA_WRITING
69 || s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) {
70 if (s->session != NULL && s->session->ext.max_early_data > 0) {
71 alg_enc = s->session->cipher->algorithm_enc;
73 if (!ossl_assert(s->psksession != NULL
74 && s->psksession->ext.max_early_data > 0)) {
75 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
76 ERR_R_INTERNAL_ERROR);
79 alg_enc = s->psksession->cipher->algorithm_enc;
83 * To get here we must have selected a ciphersuite - otherwise ctx would
86 if (!ossl_assert(s->s3.tmp.new_cipher != NULL)) {
87 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
88 ERR_R_INTERNAL_ERROR);
91 alg_enc = s->s3.tmp.new_cipher->algorithm_enc;
94 if (alg_enc & SSL_AESCCM) {
95 if (alg_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
96 taglen = EVP_CCM8_TLS_TAG_LEN;
98 taglen = EVP_CCM_TLS_TAG_LEN;
99 if (sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
101 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
102 ERR_R_INTERNAL_ERROR);
105 } else if (alg_enc & SSL_AESGCM) {
106 taglen = EVP_GCM_TLS_TAG_LEN;
107 } else if (alg_enc & SSL_CHACHA20) {
108 taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
110 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
111 ERR_R_INTERNAL_ERROR);
117 * Take off tag. There must be at least one byte of content type as
120 if (rec->length < taglen + 1)
122 rec->length -= taglen;
126 if (ivlen < SEQ_NUM_SIZE) {
127 /* Should not happen */
128 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
129 ERR_R_INTERNAL_ERROR);
132 offset = ivlen - SEQ_NUM_SIZE;
133 memcpy(iv, staticiv, offset);
134 for (loop = 0; loop < SEQ_NUM_SIZE; loop++)
135 iv[offset + loop] = staticiv[offset + loop] ^ seq[loop];
137 /* Increment the sequence counter */
138 for (loop = SEQ_NUM_SIZE; loop > 0; loop--) {
140 if (seq[loop - 1] != 0)
144 /* Sequence has wrapped */
148 /* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
149 if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, sending) <= 0
150 || (!sending && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
152 rec->data + rec->length) <= 0)) {
153 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
154 ERR_R_INTERNAL_ERROR);
159 if (!WPACKET_init_static_len(&wpkt, recheader, sizeof(recheader), 0)
160 || !WPACKET_put_bytes_u8(&wpkt, rec->type)
161 || !WPACKET_put_bytes_u16(&wpkt, rec->rec_version)
162 || !WPACKET_put_bytes_u16(&wpkt, rec->length + taglen)
163 || !WPACKET_get_total_written(&wpkt, &hdrlen)
164 || hdrlen != SSL3_RT_HEADER_LENGTH
165 || !WPACKET_finish(&wpkt)) {
166 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
167 ERR_R_INTERNAL_ERROR);
168 WPACKET_cleanup(&wpkt);
173 * For CCM we must explicitly set the total plaintext length before we add
176 if (((alg_enc & SSL_AESCCM) != 0
177 && EVP_CipherUpdate(ctx, NULL, &lenu, NULL,
178 (unsigned int)rec->length) <= 0)
179 || EVP_CipherUpdate(ctx, NULL, &lenu, recheader,
180 sizeof(recheader)) <= 0
181 || EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
182 (unsigned int)rec->length) <= 0
183 || EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
184 || (size_t)(lenu + lenf) != rec->length) {
189 if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
190 rec->data + rec->length) <= 0) {
191 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_ENC,
192 ERR_R_INTERNAL_ERROR);
195 rec->length += taglen;