| /* |
| * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include "../ssl_local.h" |
| #include "record_local.h" |
| #include "internal/cryptlib.h" |
| |
| /*- |
| * tls13_enc encrypts/decrypts |n_recs| in |recs|. Calls SSLfatal on internal |
| * error, but not otherwise. It is the responsibility of the caller to report |
| * a bad_record_mac. |
| * |
| * Returns: |
| * 0: On failure |
| * 1: if the record encryption/decryption was successful. |
| */ |
| int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending, |
| ossl_unused SSL_MAC_BUF *mac, ossl_unused size_t macsize) |
| { |
| 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 */ |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| 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_get_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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| 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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| 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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| } 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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| 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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| 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 0; |
| } |
| |
| 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)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| /* 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)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); |
| WPACKET_cleanup(&wpkt); |
| return 0; |
| } |
| |
| /* |
| * 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 0; |
| } |
| 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, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| rec->length += taglen; |
| } |
| |
| return 1; |
| } |