/* * Copyright 1995-2021 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 #include #include #include "record_local.h" #include "internal/cryptlib.h" static const unsigned char ssl3_pad_1[48] = { 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36 }; static const unsigned char ssl3_pad_2[48] = { 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c }; /* * Clear the contents of an SSL3_RECORD but retain any memory allocated */ void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs) { unsigned char *comp; size_t i; for (i = 0; i < num_recs; i++) { comp = r[i].comp; memset(&r[i], 0, sizeof(*r)); r[i].comp = comp; } } void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs) { size_t i; for (i = 0; i < num_recs; i++) { OPENSSL_free(r[i].comp); r[i].comp = NULL; } } void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num) { memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE); } /* * Peeks ahead into "read_ahead" data to see if we have a whole record waiting * for us in the buffer. */ static int ssl3_record_app_data_waiting(SSL *s) { SSL3_BUFFER *rbuf; size_t left, len; unsigned char *p; rbuf = RECORD_LAYER_get_rbuf(&s->rlayer); p = SSL3_BUFFER_get_buf(rbuf); if (p == NULL) return 0; left = SSL3_BUFFER_get_left(rbuf); if (left < SSL3_RT_HEADER_LENGTH) return 0; p += SSL3_BUFFER_get_offset(rbuf); /* * We only check the type and record length, we will sanity check version * etc later */ if (*p != SSL3_RT_APPLICATION_DATA) return 0; p += 3; n2s(p, len); if (left < SSL3_RT_HEADER_LENGTH + len) return 0; return 1; } int early_data_count_ok(SSL *s, size_t length, size_t overhead, int send) { uint32_t max_early_data; SSL_SESSION *sess = s->session; /* * If we are a client then we always use the max_early_data from the * session/psksession. Otherwise we go with the lowest out of the max early * data set in the session and the configured max_early_data. */ if (!s->server && sess->ext.max_early_data == 0) { 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; } sess = s->psksession; } if (!s->server) max_early_data = sess->ext.max_early_data; else if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED) max_early_data = s->recv_max_early_data; else max_early_data = s->recv_max_early_data < sess->ext.max_early_data ? s->recv_max_early_data : sess->ext.max_early_data; if (max_early_data == 0) { SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE, SSL_R_TOO_MUCH_EARLY_DATA); return 0; } /* If we are dealing with ciphertext we need to allow for the overhead */ max_early_data += overhead; if (s->early_data_count + length > max_early_data) { SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE, SSL_R_TOO_MUCH_EARLY_DATA); return 0; } s->early_data_count += length; return 1; } /* * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that * will be processed per call to ssl3_get_record. Without this limit an * attacker could send empty records at a faster rate than we can process and * cause ssl3_get_record to loop forever. */ #define MAX_EMPTY_RECORDS 32 #define SSL2_RT_HEADER_LENGTH 2 /*- * Call this to get new input records. * It will return <= 0 if more data is needed, normally due to an error * or non-blocking IO. * When it finishes, |numrpipes| records have been decoded. For each record 'i': * rr[i].type - is the type of record * rr[i].data, - data * rr[i].length, - number of bytes * Multiple records will only be returned if the record types are all * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <= * |max_pipelines| */ /* used only by ssl3_read_bytes */ int ssl3_get_record(SSL *s) { int enc_err, rret; int i; size_t more, n; SSL3_RECORD *rr, *thisrr; SSL3_BUFFER *rbuf; SSL_SESSION *sess; unsigned char *p; unsigned char md[EVP_MAX_MD_SIZE]; unsigned int version; size_t mac_size = 0; int imac_size; size_t num_recs = 0, max_recs, j; PACKET pkt, sslv2pkt; int is_ktls_left; SSL_MAC_BUF *macbufs = NULL; int ret = -1; rr = RECORD_LAYER_get_rrec(&s->rlayer); rbuf = RECORD_LAYER_get_rbuf(&s->rlayer); is_ktls_left = (SSL3_BUFFER_get_left(rbuf) > 0); max_recs = s->max_pipelines; if (max_recs == 0) max_recs = 1; sess = s->session; do { thisrr = &rr[num_recs]; /* check if we have the header */ if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || (RECORD_LAYER_get_packet_length(&s->rlayer) < SSL3_RT_HEADER_LENGTH)) { size_t sslv2len; unsigned int type; rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, SSL3_BUFFER_get_len(rbuf), 0, num_recs == 0 ? 1 : 0, &n); if (rret <= 0) { #ifndef OPENSSL_NO_KTLS if (!BIO_get_ktls_recv(s->rbio) || rret == 0) return rret; /* error or non-blocking */ switch (errno) { case EBADMSG: SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); break; case EMSGSIZE: SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_PACKET_LENGTH_TOO_LONG); break; case EINVAL: SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_R_WRONG_VERSION_NUMBER); break; default: break; } #endif return rret; } RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); p = RECORD_LAYER_get_packet(&s->rlayer); if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer), RECORD_LAYER_get_packet_length(&s->rlayer))) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return -1; } sslv2pkt = pkt; if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len) || !PACKET_get_1(&sslv2pkt, &type)) { SSLfatal(s, SSL_AD_DECODE_ERROR, ERR_R_INTERNAL_ERROR); return -1; } /* * The first record received by the server may be a V2ClientHello. */ if (s->server && RECORD_LAYER_is_first_record(&s->rlayer) && (sslv2len & 0x8000) != 0 && (type == SSL2_MT_CLIENT_HELLO)) { /* * SSLv2 style record * * |num_recs| here will actually always be 0 because * |num_recs > 0| only ever occurs when we are processing * multiple app data records - which we know isn't the case here * because it is an SSLv2ClientHello. We keep it using * |num_recs| for the sake of consistency */ thisrr->type = SSL3_RT_HANDSHAKE; thisrr->rec_version = SSL2_VERSION; thisrr->length = sslv2len & 0x7fff; if (thisrr->length > SSL3_BUFFER_get_len(rbuf) - SSL2_RT_HEADER_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_PACKET_LENGTH_TOO_LONG); return -1; } if (thisrr->length < MIN_SSL2_RECORD_LEN) { SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_TOO_SHORT); return -1; } } else { /* SSLv3+ style record */ /* Pull apart the header into the SSL3_RECORD */ if (!PACKET_get_1(&pkt, &type) || !PACKET_get_net_2(&pkt, &version) || !PACKET_get_net_2_len(&pkt, &thisrr->length)) { if (s->msg_callback) s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg); SSLfatal(s, SSL_AD_DECODE_ERROR, ERR_R_INTERNAL_ERROR); return -1; } thisrr->type = type; thisrr->rec_version = version; if (s->msg_callback) s->msg_callback(0, version, SSL3_RT_HEADER, p, 5, s, s->msg_callback_arg); /* * Lets check version. In TLSv1.3 we only check this field * when encryption is occurring (see later check). For the * ServerHello after an HRR we haven't actually selected TLSv1.3 * yet, but we still treat it as TLSv1.3, so we must check for * that explicitly */ if (!s->first_packet && !SSL_IS_TLS13(s) && s->hello_retry_request != SSL_HRR_PENDING && version != (unsigned int)s->version) { if ((s->version & 0xFF00) == (version & 0xFF00) && !s->enc_write_ctx && !s->write_hash) { if (thisrr->type == SSL3_RT_ALERT) { /* * The record is using an incorrect version number, * but what we've got appears to be an alert. We * haven't read the body yet to check whether its a * fatal or not - but chances are it is. We probably * shouldn't send a fatal alert back. We'll just * end. */ SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_WRONG_VERSION_NUMBER); return -1; } /* * Send back error using their minor version number :-) */ s->version = (unsigned short)version; } SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_R_WRONG_VERSION_NUMBER); return -1; } if ((version >> 8) != SSL3_VERSION_MAJOR) { if (RECORD_LAYER_is_first_record(&s->rlayer)) { /* Go back to start of packet, look at the five bytes * that we have. */ p = RECORD_LAYER_get_packet(&s->rlayer); if (HAS_PREFIX((char *)p, "GET ") || HAS_PREFIX((char *)p, "POST ") || HAS_PREFIX((char *)p, "HEAD ") || HAS_PREFIX((char *)p, "PUT ")) { SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_HTTP_REQUEST); return -1; } else if (HAS_PREFIX((char *)p, "CONNE")) { SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_HTTPS_PROXY_REQUEST); return -1; } /* Doesn't look like TLS - don't send an alert */ SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_WRONG_VERSION_NUMBER); return -1; } else { SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_R_WRONG_VERSION_NUMBER); return -1; } } if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) { if (thisrr->type != SSL3_RT_APPLICATION_DATA && (thisrr->type != SSL3_RT_CHANGE_CIPHER_SPEC || !SSL_IS_FIRST_HANDSHAKE(s)) && (thisrr->type != SSL3_RT_ALERT || s->statem.enc_read_state != ENC_READ_STATE_ALLOW_PLAIN_ALERTS)) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_BAD_RECORD_TYPE); return -1; } if (thisrr->rec_version != TLS1_2_VERSION) { SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_WRONG_VERSION_NUMBER); return -1; } } if (thisrr->length > SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_PACKET_LENGTH_TOO_LONG); return -1; } } /* now s->rlayer.rstate == SSL_ST_READ_BODY */ } if (SSL_IS_TLS13(s)) { if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); return -1; } } else { size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH; #ifndef OPENSSL_NO_COMP /* * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH * does not include the compression overhead anyway. */ if (s->expand == NULL) len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD; #endif /* KTLS may use all of the buffer */ if (BIO_get_ktls_recv(s->rbio) && !is_ktls_left) len = SSL3_BUFFER_get_left(rbuf); if (thisrr->length > len) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); return -1; } } /* * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data. * Calculate how much more data we need to read for the rest of the * record */ if (thisrr->rec_version == SSL2_VERSION) { more = thisrr->length + SSL2_RT_HEADER_LENGTH - SSL3_RT_HEADER_LENGTH; } else { more = thisrr->length; } if (more > 0) { /* now s->rlayer.packet_length == SSL3_RT_HEADER_LENGTH */ rret = ssl3_read_n(s, more, more, 1, 0, &n); if (rret <= 0) return rret; /* error or non-blocking io */ } /* set state for later operations */ RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); /* * At this point, s->rlayer.packet_length == SSL3_RT_HEADER_LENGTH * + thisrr->length, or s->rlayer.packet_length == SSL2_RT_HEADER_LENGTH * + thisrr->length and we have that many bytes in s->rlayer.packet */ if (thisrr->rec_version == SSL2_VERSION) { thisrr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]); } else { thisrr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]); } /* * ok, we can now read from 's->rlayer.packet' data into 'thisrr'. * thisrr->input points at thisrr->length bytes, which need to be copied * into thisrr->data by either the decryption or by the decompression. * When the data is 'copied' into the thisrr->data buffer, * thisrr->input will be updated to point at the new buffer */ /* * We now have - encrypted [ MAC [ compressed [ plain ] ] ] * thisrr->length bytes of encrypted compressed stuff. */ /* decrypt in place in 'thisrr->input' */ thisrr->data = thisrr->input; thisrr->orig_len = thisrr->length; /* Mark this record as not read by upper layers yet */ thisrr->read = 0; num_recs++; /* we have pulled in a full packet so zero things */ RECORD_LAYER_reset_packet_length(&s->rlayer); RECORD_LAYER_clear_first_record(&s->rlayer); } while (num_recs < max_recs && thisrr->type == SSL3_RT_APPLICATION_DATA && SSL_USE_EXPLICIT_IV(s) && s->enc_read_ctx != NULL && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_read_ctx)) & EVP_CIPH_FLAG_PIPELINE) != 0 && ssl3_record_app_data_waiting(s)); if (num_recs == 1 && thisrr->type == SSL3_RT_CHANGE_CIPHER_SPEC && (SSL_IS_TLS13(s) || s->hello_retry_request != SSL_HRR_NONE) && SSL_IS_FIRST_HANDSHAKE(s)) { /* * CCS messages must be exactly 1 byte long, containing the value 0x01 */ if (thisrr->length != 1 || thisrr->data[0] != 0x01) { SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_INVALID_CCS_MESSAGE); return -1; } /* * CCS messages are ignored in TLSv1.3. We treat it like an empty * handshake record */ thisrr->type = SSL3_RT_HANDSHAKE; RECORD_LAYER_inc_empty_record_count(&s->rlayer); if (RECORD_LAYER_get_empty_record_count(&s->rlayer) > MAX_EMPTY_RECORDS) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_CCS_MESSAGE); return -1; } thisrr->read = 1; RECORD_LAYER_set_numrpipes(&s->rlayer, 1); return 1; } /* * KTLS reads full records. If there is any data left, * then it is from before enabling ktls */ if (BIO_get_ktls_recv(s->rbio) && !is_ktls_left) goto skip_decryption; if (s->read_hash != NULL) { const EVP_MD *tmpmd = EVP_MD_CTX_get0_md(s->read_hash); if (tmpmd != NULL) { imac_size = EVP_MD_get_size(tmpmd); if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB); return -1; } mac_size = (size_t)imac_size; } } /* * If in encrypt-then-mac mode calculate mac from encrypted record. All * the details below are public so no timing details can leak. */ if (SSL_READ_ETM(s) && s->read_hash) { unsigned char *mac; for (j = 0; j < num_recs; j++) { thisrr = &rr[j]; if (thisrr->length < mac_size) { SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_TOO_SHORT); return -1; } thisrr->length -= mac_size; mac = thisrr->data + thisrr->length; i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ ); if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) { SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); return -1; } } /* * We've handled the mac now - there is no MAC inside the encrypted * record */ mac_size = 0; } if (mac_size > 0) { macbufs = OPENSSL_zalloc(sizeof(*macbufs) * num_recs); if (macbufs == NULL) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE); return -1; } } enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0, macbufs, mac_size); /*- * enc_err is: * 0: if the record is publicly invalid, or an internal error, or AEAD * decryption failed, or ETM decryption failed. * 1: Success or MTE decryption failed (MAC will be randomised) */ if (enc_err == 0) { if (ossl_statem_in_error(s)) { /* SSLfatal() already got called */ goto end; } if (num_recs == 1 && ossl_statem_skip_early_data(s)) { /* * Valid early_data that we cannot decrypt will fail here. We treat * it like an empty record. */ thisrr = &rr[0]; if (!early_data_count_ok(s, thisrr->length, EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) { /* SSLfatal() already called */ goto end; } thisrr->length = 0; thisrr->read = 1; RECORD_LAYER_set_numrpipes(&s->rlayer, 1); RECORD_LAYER_reset_read_sequence(&s->rlayer); ret = 1; goto end; } SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); goto end; } OSSL_TRACE_BEGIN(TLS) { BIO_printf(trc_out, "dec %lu\n", (unsigned long)rr[0].length); BIO_dump_indent(trc_out, rr[0].data, rr[0].length, 4); } OSSL_TRACE_END(TLS); /* r->length is now the compressed data plus mac */ if ((sess != NULL) && (s->enc_read_ctx != NULL) && (!SSL_READ_ETM(s) && EVP_MD_CTX_get0_md(s->read_hash) != NULL)) { /* s->read_hash != NULL => mac_size != -1 */ for (j = 0; j < num_recs; j++) { SSL_MAC_BUF *thismb = &macbufs[j]; thisrr = &rr[j]; i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ ); if (i == 0 || thismb == NULL || thismb->mac == NULL || CRYPTO_memcmp(md, thismb->mac, (size_t)mac_size) != 0) enc_err = 0; if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) enc_err = 0; } } if (enc_err == 0) { if (ossl_statem_in_error(s)) { /* We already called SSLfatal() */ goto end; } /* * A separate 'decryption_failed' alert was introduced with TLS 1.0, * SSL 3.0 only has 'bad_record_mac'. But unless a decryption * failure is directly visible from the ciphertext anyway, we should * not reveal which kind of error occurred -- this might become * visible to an attacker (e.g. via a logfile) */ SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); goto end; } skip_decryption: for (j = 0; j < num_recs; j++) { thisrr = &rr[j]; /* thisrr->length is now just compressed */ if (s->expand != NULL) { if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_COMPRESSED_LENGTH_TOO_LONG); goto end; } if (!ssl3_do_uncompress(s, thisrr)) { SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_R_BAD_DECOMPRESSION); goto end; } } if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL && thisrr->type != SSL3_RT_ALERT) { size_t end; if (thisrr->length == 0 || thisrr->type != SSL3_RT_APPLICATION_DATA) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_BAD_RECORD_TYPE); goto end; } /* Strip trailing padding */ for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0; end--) continue; thisrr->length = end; thisrr->type = thisrr->data[end]; if (thisrr->type != SSL3_RT_APPLICATION_DATA && thisrr->type != SSL3_RT_ALERT && thisrr->type != SSL3_RT_HANDSHAKE) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_BAD_RECORD_TYPE); goto end; } if (s->msg_callback) s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE, &thisrr->data[end], 1, s, s->msg_callback_arg); } /* * TLSv1.3 alert and handshake records are required to be non-zero in * length. */ if (SSL_IS_TLS13(s) && (thisrr->type == SSL3_RT_HANDSHAKE || thisrr->type == SSL3_RT_ALERT) && thisrr->length == 0) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_BAD_LENGTH); goto end; } /* * Usually thisrr->length is the length of a single record, but when * KTLS handles the decryption, thisrr->length may be larger than * SSL3_RT_MAX_PLAIN_LENGTH because the kernel may have coalesced * multiple records. * Therefore we have to rely on KTLS to check the plaintext length * limit in the kernel. */ if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH && (!BIO_get_ktls_recv(s->rbio) || is_ktls_left)) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_DATA_LENGTH_TOO_LONG); goto end; } /* * Check if the received packet overflows the current * Max Fragment Length setting. * Note: USE_MAX_FRAGMENT_LENGTH_EXT and KTLS are mutually exclusive. */ if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) && thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_DATA_LENGTH_TOO_LONG); goto end; } thisrr->off = 0; /*- * So at this point the following is true * thisrr->type is the type of record * thisrr->length == number of bytes in record * thisrr->off == offset to first valid byte * thisrr->data == where to take bytes from, increment after use :-). */ /* just read a 0 length packet */ if (thisrr->length == 0) { RECORD_LAYER_inc_empty_record_count(&s->rlayer); if (RECORD_LAYER_get_empty_record_count(&s->rlayer) > MAX_EMPTY_RECORDS) { SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_RECORD_TOO_SMALL); goto end; } } else { RECORD_LAYER_reset_empty_record_count(&s->rlayer); } } if (s->early_data_state == SSL_EARLY_DATA_READING) { thisrr = &rr[0]; if (thisrr->type == SSL3_RT_APPLICATION_DATA && !early_data_count_ok(s, thisrr->length, 0, 0)) { /* SSLfatal already called */ goto end; } } RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs); ret = 1; end: if (macbufs != NULL) { for (j = 0; j < num_recs; j++) { if (macbufs[j].alloced) OPENSSL_free(macbufs[j].mac); } OPENSSL_free(macbufs); } return ret; } int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr) { #ifndef OPENSSL_NO_COMP int i; if (rr->comp == NULL) { rr->comp = (unsigned char *) OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH); } if (rr->comp == NULL) return 0; i = COMP_expand_block(ssl->expand, rr->comp, SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length); if (i < 0) return 0; else rr->length = i; rr->data = rr->comp; #endif return 1; } int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr) { #ifndef OPENSSL_NO_COMP int i; i = COMP_compress_block(ssl->compress, wr->data, (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD), wr->input, (int)wr->length); if (i < 0) return 0; else wr->length = i; wr->input = wr->data; #endif return 1; } /*- * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|. Calls SSLfatal on * internal error, but not otherwise. It is the responsibility of the caller to * report a bad_record_mac * * Returns: * 0: if the record is publicly invalid, or an internal error * 1: Success or Mac-then-encrypt decryption failed (MAC will be randomised) */ int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending, SSL_MAC_BUF *mac, size_t macsize) { SSL3_RECORD *rec; EVP_CIPHER_CTX *ds; size_t l, i; size_t bs; const EVP_CIPHER *enc; rec = inrecs; /* * We shouldn't ever be called with more than one record in the SSLv3 case */ if (n_recs != 1) return 0; if (sending) { ds = s->enc_write_ctx; if (s->enc_write_ctx == NULL) enc = NULL; else enc = EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx); } else { ds = s->enc_read_ctx; if (s->enc_read_ctx == NULL) enc = NULL; else enc = EVP_CIPHER_CTX_get0_cipher(s->enc_read_ctx); } if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { memmove(rec->data, rec->input, rec->length); rec->input = rec->data; } else { int provided = (EVP_CIPHER_get0_provider(enc) != NULL); l = rec->length; bs = EVP_CIPHER_CTX_get_block_size(ds); /* COMPRESS */ if ((bs != 1) && sending && !provided) { /* * We only do this for legacy ciphers. Provided ciphers add the * padding on the provider side. */ i = bs - (l % bs); /* we need to add 'i-1' padding bytes */ l += i; /* * the last of these zero bytes will be overwritten with the * padding length. */ memset(&rec->input[rec->length], 0, i); rec->length += i; rec->input[l - 1] = (unsigned char)(i - 1); } if (!sending) { if (l == 0 || l % bs != 0) { /* Publicly invalid */ return 0; } /* otherwise, rec->length >= bs */ } if (EVP_CIPHER_get0_provider(enc) != NULL) { int outlen; if (!EVP_CipherUpdate(ds, rec->data, &outlen, rec->input, (unsigned int)l)) return 0; rec->length = outlen; if (!sending && mac != NULL) { /* Now get a pointer to the MAC */ OSSL_PARAM params[2], *p = params; /* Get the MAC */ mac->alloced = 0; *p++ = OSSL_PARAM_construct_octet_ptr(OSSL_CIPHER_PARAM_TLS_MAC, (void **)&mac->mac, macsize); *p = OSSL_PARAM_construct_end(); if (!EVP_CIPHER_CTX_get_params(ds, params)) { /* Shouldn't normally happen */ SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } } else { if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1) { /* Shouldn't happen */ SSLfatal(s, SSL_AD_BAD_RECORD_MAC, ERR_R_INTERNAL_ERROR); return 0; } if (!sending) return ssl3_cbc_remove_padding_and_mac(&rec->length, rec->orig_len, rec->data, (mac != NULL) ? &mac->mac : NULL, (mac != NULL) ? &mac->alloced : NULL, bs, macsize, s->ctx->libctx); } } return 1; } #define MAX_PADDING 256 /*- * tls1_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 - if appropriate (DTLS just drops the record). * * Returns: * 0: if the record is publicly invalid, or an internal error, or AEAD * decryption failed, or Encrypt-then-mac decryption failed. * 1: Success or Mac-then-encrypt decryption failed (MAC will be randomised) */ int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending, SSL_MAC_BUF *macs, size_t macsize) { EVP_CIPHER_CTX *ds; size_t reclen[SSL_MAX_PIPELINES]; unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN]; int i, pad = 0, tmpr; size_t bs, ctr, padnum, loop; unsigned char padval; const EVP_CIPHER *enc; int tlstree_enc = sending ? (s->mac_flags & SSL_MAC_FLAG_WRITE_MAC_TLSTREE) : (s->mac_flags & SSL_MAC_FLAG_READ_MAC_TLSTREE); if (n_recs == 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } if (sending) { if (EVP_MD_CTX_get0_md(s->write_hash)) { int n = EVP_MD_CTX_get_size(s->write_hash); if (!ossl_assert(n >= 0)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } ds = s->enc_write_ctx; if (s->enc_write_ctx == NULL) enc = NULL; else { int ivlen; enc = EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx); /* For TLSv1.1 and later explicit IV */ if (SSL_USE_EXPLICIT_IV(s) && EVP_CIPHER_get_mode(enc) == EVP_CIPH_CBC_MODE) ivlen = EVP_CIPHER_get_iv_length(enc); else ivlen = 0; if (ivlen > 1) { for (ctr = 0; ctr < n_recs; ctr++) { if (recs[ctr].data != recs[ctr].input) { /* * we can't write into the input stream: Can this ever * happen?? (steve) */ SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } else if (RAND_bytes_ex(s->ctx->libctx, recs[ctr].input, ivlen, 0) <= 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } } } } else { if (EVP_MD_CTX_get0_md(s->read_hash)) { int n = EVP_MD_CTX_get_size(s->read_hash); if (!ossl_assert(n >= 0)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } ds = s->enc_read_ctx; if (s->enc_read_ctx == NULL) enc = NULL; else enc = EVP_CIPHER_CTX_get0_cipher(s->enc_read_ctx); } if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) { for (ctr = 0; ctr < n_recs; ctr++) { memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length); recs[ctr].input = recs[ctr].data; } } else { int provided = (EVP_CIPHER_get0_provider(enc) != NULL); bs = EVP_CIPHER_get_block_size(EVP_CIPHER_CTX_get0_cipher(ds)); if (n_recs > 1) { if ((EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ds)) & EVP_CIPH_FLAG_PIPELINE) == 0) { /* * We shouldn't have been called with pipeline data if the * cipher doesn't support pipelining */ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_PIPELINE_FAILURE); return 0; } } for (ctr = 0; ctr < n_recs; ctr++) { reclen[ctr] = recs[ctr].length; if ((EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ds)) & EVP_CIPH_FLAG_AEAD_CIPHER) != 0) { unsigned char *seq; seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer) : RECORD_LAYER_get_read_sequence(&s->rlayer); if (SSL_IS_DTLS(s)) { /* DTLS does not support pipelining */ unsigned char dtlsseq[8], *p = dtlsseq; s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) : DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p); memcpy(p, &seq[2], 6); memcpy(buf[ctr], dtlsseq, 8); } else { memcpy(buf[ctr], seq, 8); for (i = 7; i >= 0; i--) { /* increment */ ++seq[i]; if (seq[i] != 0) break; } } buf[ctr][8] = recs[ctr].type; buf[ctr][9] = (unsigned char)(s->version >> 8); buf[ctr][10] = (unsigned char)(s->version); buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8); buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff); pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD, EVP_AEAD_TLS1_AAD_LEN, buf[ctr]); if (pad <= 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } if (sending) { reclen[ctr] += pad; recs[ctr].length += pad; } } else if ((bs != 1) && sending && !provided) { /* * We only do this for legacy ciphers. Provided ciphers add the * padding on the provider side. */ padnum = bs - (reclen[ctr] % bs); /* Add weird padding of up to 256 bytes */ if (padnum > MAX_PADDING) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } /* we need to add 'padnum' padding bytes of value padval */ padval = (unsigned char)(padnum - 1); for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++) recs[ctr].input[loop] = padval; reclen[ctr] += padnum; recs[ctr].length += padnum; } if (!sending) { if (reclen[ctr] == 0 || reclen[ctr] % bs != 0) { /* Publicly invalid */ return 0; } } } if (n_recs > 1) { unsigned char *data[SSL_MAX_PIPELINES]; /* Set the output buffers */ for (ctr = 0; ctr < n_recs; ctr++) { data[ctr] = recs[ctr].data; } if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS, (int)n_recs, data) <= 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_PIPELINE_FAILURE); return 0; } /* Set the input buffers */ for (ctr = 0; ctr < n_recs; ctr++) { data[ctr] = recs[ctr].input; } if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS, (int)n_recs, data) <= 0 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS, (int)n_recs, reclen) <= 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_PIPELINE_FAILURE); return 0; } } if (!SSL_IS_DTLS(s) && tlstree_enc) { unsigned char *seq; int decrement_seq = 0; /* * When sending, seq is incremented after MAC calculation. * So if we are in ETM mode, we use seq 'as is' in the ctrl-function. * Otherwise we have to decrease it in the implementation */ if (sending && !SSL_WRITE_ETM(s)) decrement_seq = 1; seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer) : RECORD_LAYER_get_read_sequence(&s->rlayer); if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_TLSTREE, decrement_seq, seq) <= 0) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } if (provided) { int outlen; /* Provided cipher - we do not support pipelining on this path */ if (n_recs > 1) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } if (!EVP_CipherUpdate(ds, recs[0].data, &outlen, recs[0].input, (unsigned int)reclen[0])) return 0; recs[0].length = outlen; /* * The length returned from EVP_CipherUpdate above is the actual * payload length. We need to adjust the data/input ptr to skip over * any explicit IV */ if (!sending) { if (EVP_CIPHER_get_mode(enc) == EVP_CIPH_GCM_MODE) { recs[0].data += EVP_GCM_TLS_EXPLICIT_IV_LEN; recs[0].input += EVP_GCM_TLS_EXPLICIT_IV_LEN; } else if (EVP_CIPHER_get_mode(enc) == EVP_CIPH_CCM_MODE) { recs[0].data += EVP_CCM_TLS_EXPLICIT_IV_LEN; recs[0].input += EVP_CCM_TLS_EXPLICIT_IV_LEN; } else if (bs != 1 && SSL_USE_EXPLICIT_IV(s)) { recs[0].data += bs; recs[0].input += bs; recs[0].orig_len -= bs; } /* Now get a pointer to the MAC (if applicable) */ if (macs != NULL) { OSSL_PARAM params[2], *p = params; /* Get the MAC */ macs[0].alloced = 0; *p++ = OSSL_PARAM_construct_octet_ptr(OSSL_CIPHER_PARAM_TLS_MAC, (void **)&macs[0].mac, macsize); *p = OSSL_PARAM_construct_end(); if (!EVP_CIPHER_CTX_get_params(ds, params)) { /* Shouldn't normally happen */ SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return 0; } } } } else { /* Legacy cipher */ tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input, (unsigned int)reclen[0]); if ((EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(ds)) & EVP_CIPH_FLAG_CUSTOM_CIPHER) != 0 ? (tmpr < 0) : (tmpr == 0)) { /* AEAD can fail to verify MAC */ return 0; } if (!sending) { for (ctr = 0; ctr < n_recs; ctr++) { /* Adjust the record to remove the explicit IV/MAC/Tag */ if (EVP_CIPHER_get_mode(enc) == EVP_CIPH_GCM_MODE) { recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN; recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN; recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN; } else if (EVP_CIPHER_get_mode(enc) == EVP_CIPH_CCM_MODE) { recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN; recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN; recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN; } else if (bs != 1 && SSL_USE_EXPLICIT_IV(s)) { if (recs[ctr].length < bs) return 0; recs[ctr].data += bs; recs[ctr].input += bs; recs[ctr].length -= bs; recs[ctr].orig_len -= bs; } /* * If using Mac-then-encrypt, then this will succeed but * with a random MAC if padding is invalid */ if (!tls1_cbc_remove_padding_and_mac(&recs[ctr].length, recs[ctr].orig_len, recs[ctr].data, (macs != NULL) ? &macs[ctr].mac : NULL, (macs != NULL) ? &macs[ctr].alloced : NULL, bs, pad ? (size_t)pad : macsize, (EVP_CIPHER_get_flags(enc) & EVP_CIPH_FLAG_AEAD_CIPHER) != 0, s->ctx->libctx)) return 0; } } } } return 1; } /* * ssl3_cbc_record_digest_supported returns 1 iff |ctx| uses a hash function * which ssl3_cbc_digest_record supports. */ char ssl3_cbc_record_digest_supported(const EVP_MD_CTX *ctx) { switch (EVP_MD_CTX_get_type(ctx)) { case NID_md5: case NID_sha1: case NID_sha224: case NID_sha256: case NID_sha384: case NID_sha512: return 1; default: return 0; } } int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending) { unsigned char *mac_sec, *seq; const EVP_MD_CTX *hash; unsigned char *p, rec_char; size_t md_size; size_t npad; int t; if (sending) { mac_sec = &(ssl->s3.write_mac_secret[0]); seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); hash = ssl->write_hash; } else { mac_sec = &(ssl->s3.read_mac_secret[0]); seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); hash = ssl->read_hash; } t = EVP_MD_CTX_get_size(hash); if (t < 0) return 0; md_size = t; npad = (48 / md_size) * md_size; if (!sending && EVP_CIPHER_CTX_get_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && ssl3_cbc_record_digest_supported(hash)) { #ifdef OPENSSL_NO_DEPRECATED_3_0 return 0; #else /* * This is a CBC-encrypted record. We must avoid leaking any * timing-side channel information about how many blocks of data we * are hashing because that gives an attacker a timing-oracle. */ /*- * npad is, at most, 48 bytes and that's with MD5: * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75. * * With SHA-1 (the largest hash speced for SSLv3) the hash size * goes up 4, but npad goes down by 8, resulting in a smaller * total size. */ unsigned char header[75]; size_t j = 0; memcpy(header + j, mac_sec, md_size); j += md_size; memcpy(header + j, ssl3_pad_1, npad); j += npad; memcpy(header + j, seq, 8); j += 8; header[j++] = rec->type; header[j++] = (unsigned char)(rec->length >> 8); header[j++] = (unsigned char)(rec->length & 0xff); /* Final param == is SSLv3 */ if (ssl3_cbc_digest_record(EVP_MD_CTX_get0_md(hash), md, &md_size, header, rec->input, rec->length, rec->orig_len, mac_sec, md_size, 1) <= 0) return 0; #endif } else { unsigned int md_size_u; /* Chop the digest off the end :-) */ EVP_MD_CTX *md_ctx = EVP_MD_CTX_new(); if (md_ctx == NULL) return 0; rec_char = rec->type; p = md; s2n(rec->length, p); if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0 || EVP_DigestUpdate(md_ctx, md, 2) <= 0 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) { EVP_MD_CTX_free(md_ctx); return 0; } EVP_MD_CTX_free(md_ctx); } ssl3_record_sequence_update(seq); return 1; } int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending) { unsigned char *seq; EVP_MD_CTX *hash; size_t md_size; int i; EVP_MD_CTX *hmac = NULL, *mac_ctx; unsigned char header[13]; int stream_mac = sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM) : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM); int tlstree_mac = sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_TLSTREE) : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_TLSTREE); int t; int ret = 0; if (sending) { seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer); hash = ssl->write_hash; } else { seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer); hash = ssl->read_hash; } t = EVP_MD_CTX_get_size(hash); if (!ossl_assert(t >= 0)) return 0; md_size = t; /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */ if (stream_mac) { mac_ctx = hash; } else { hmac = EVP_MD_CTX_new(); if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash)) { goto end; } mac_ctx = hmac; } if (!SSL_IS_DTLS(ssl) && tlstree_mac && EVP_MD_CTX_ctrl(mac_ctx, EVP_MD_CTRL_TLSTREE, 0, seq) <= 0) { goto end; } if (SSL_IS_DTLS(ssl)) { unsigned char dtlsseq[8], *p = dtlsseq; s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) : DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p); memcpy(p, &seq[2], 6); memcpy(header, dtlsseq, 8); } else memcpy(header, seq, 8); header[8] = rec->type; header[9] = (unsigned char)(ssl->version >> 8); header[10] = (unsigned char)(ssl->version); header[11] = (unsigned char)(rec->length >> 8); header[12] = (unsigned char)(rec->length & 0xff); if (!sending && !SSL_READ_ETM(ssl) && EVP_CIPHER_CTX_get_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE && ssl3_cbc_record_digest_supported(mac_ctx)) { OSSL_PARAM tls_hmac_params[2], *p = tls_hmac_params; *p++ = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_TLS_DATA_SIZE, &rec->orig_len); *p++ = OSSL_PARAM_construct_end(); if (!EVP_PKEY_CTX_set_params(EVP_MD_CTX_get_pkey_ctx(mac_ctx), tls_hmac_params)) { goto end; } } if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) { goto end; } OSSL_TRACE_BEGIN(TLS) { BIO_printf(trc_out, "seq:\n"); BIO_dump_indent(trc_out, seq, 8, 4); BIO_printf(trc_out, "rec:\n"); BIO_dump_indent(trc_out, rec->data, rec->length, 4); } OSSL_TRACE_END(TLS); if (!SSL_IS_DTLS(ssl)) { for (i = 7; i >= 0; i--) { ++seq[i]; if (seq[i] != 0) break; } } OSSL_TRACE_BEGIN(TLS) { BIO_printf(trc_out, "md:\n"); BIO_dump_indent(trc_out, md, md_size, 4); } OSSL_TRACE_END(TLS); ret = 1; end: EVP_MD_CTX_free(hmac); return ret; } int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap) { int i; int enc_err; SSL_SESSION *sess; SSL3_RECORD *rr; int imac_size; size_t mac_size = 0; unsigned char md[EVP_MAX_MD_SIZE]; size_t max_plain_length = SSL3_RT_MAX_PLAIN_LENGTH; SSL_MAC_BUF macbuf = { NULL, 0 }; int ret = 0; rr = RECORD_LAYER_get_rrec(&s->rlayer); sess = s->session; /* * At this point, s->rlayer.packet_length == SSL3_RT_HEADER_LNGTH + rr->length, * and we have that many bytes in s->rlayer.packet */ rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]); /* * ok, we can now read from 's->rlayer.packet' data into 'rr'. rr->input * points at rr->length bytes, which need to be copied into rr->data by * either the decryption or by the decompression. When the data is 'copied' * into the rr->data buffer, rr->input will be pointed at the new buffer */ /* * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length * bytes of encrypted compressed stuff. */ /* check is not needed I believe */ if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); return 0; } /* decrypt in place in 'rr->input' */ rr->data = rr->input; rr->orig_len = rr->length; if (s->read_hash != NULL) { const EVP_MD *tmpmd = EVP_MD_CTX_get0_md(s->read_hash); if (tmpmd != NULL) { imac_size = EVP_MD_get_size(tmpmd); if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB); return -1; } mac_size = (size_t)imac_size; } } if (SSL_READ_ETM(s) && s->read_hash) { unsigned char *mac; if (rr->orig_len < mac_size) { SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_TOO_SHORT); return 0; } rr->length -= mac_size; mac = rr->data + rr->length; i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ ); if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) { SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); return 0; } /* * We've handled the mac now - there is no MAC inside the encrypted * record */ mac_size = 0; } /* * Set a mark around the packet decryption attempt. This is DTLS, so * bad packets are just ignored, and we don't want to leave stray * errors in the queue from processing bogus junk that we ignored. */ ERR_set_mark(); enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0, &macbuf, mac_size); /*- * enc_err is: * 0: if the record is publicly invalid, or an internal error, or AEAD * decryption failed, or ETM decryption failed. * 1: Success or MTE decryption failed (MAC will be randomised) */ if (enc_err == 0) { ERR_pop_to_mark(); if (ossl_statem_in_error(s)) { /* SSLfatal() got called */ goto end; } /* For DTLS we simply ignore bad packets. */ rr->length = 0; RECORD_LAYER_reset_packet_length(&s->rlayer); goto end; } ERR_clear_last_mark(); OSSL_TRACE_BEGIN(TLS) { BIO_printf(trc_out, "dec %zd\n", rr->length); BIO_dump_indent(trc_out, rr->data, rr->length, 4); } OSSL_TRACE_END(TLS); /* r->length is now the compressed data plus mac */ if ((sess != NULL) && !SSL_READ_ETM(s) && (s->enc_read_ctx != NULL) && (EVP_MD_CTX_get0_md(s->read_hash) != NULL)) { /* s->read_hash != NULL => mac_size != -1 */ i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ ); if (i == 0 || macbuf.mac == NULL || CRYPTO_memcmp(md, macbuf.mac, mac_size) != 0) enc_err = 0; if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) enc_err = 0; } if (enc_err == 0) { /* decryption failed, silently discard message */ rr->length = 0; RECORD_LAYER_reset_packet_length(&s->rlayer); goto end; } /* r->length is now just compressed */ if (s->expand != NULL) { if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_COMPRESSED_LENGTH_TOO_LONG); goto end; } if (!ssl3_do_uncompress(s, rr)) { SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_R_BAD_DECOMPRESSION); goto end; } } /* use current Max Fragment Length setting if applicable */ if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)) max_plain_length = GET_MAX_FRAGMENT_LENGTH(s->session); /* send overflow if the plaintext is too long now it has passed MAC */ if (rr->length > max_plain_length) { SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_R_DATA_LENGTH_TOO_LONG); goto end; } rr->off = 0; /*- * So at this point the following is true * ssl->s3.rrec.type is the type of record * ssl->s3.rrec.length == number of bytes in record * ssl->s3.rrec.off == offset to first valid byte * ssl->s3.rrec.data == where to take bytes from, increment * after use :-). */ /* we have pulled in a full packet so zero things */ RECORD_LAYER_reset_packet_length(&s->rlayer); /* Mark receipt of record. */ dtls1_record_bitmap_update(s, bitmap); ret = 1; end: if (macbuf.alloced) OPENSSL_free(macbuf.mac); return ret; } /* * Retrieve a buffered record that belongs to the current epoch, i.e. processed */ #define dtls1_get_processed_record(s) \ dtls1_retrieve_buffered_record((s), \ &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer))) /*- * Call this to get a new input record. * It will return <= 0 if more data is needed, normally due to an error * or non-blocking IO. * When it finishes, one packet has been decoded and can be found in * ssl->s3.rrec.type - is the type of record * ssl->s3.rrec.data - data * ssl->s3.rrec.length - number of bytes */ /* used only by dtls1_read_bytes */ int dtls1_get_record(SSL *s) { int ssl_major, ssl_minor; int rret; size_t more, n; SSL3_RECORD *rr; unsigned char *p = NULL; unsigned short version; DTLS1_BITMAP *bitmap; unsigned int is_next_epoch; rr = RECORD_LAYER_get_rrec(&s->rlayer); again: /* * The epoch may have changed. If so, process all the pending records. * This is a non-blocking operation. */ if (!dtls1_process_buffered_records(s)) { /* SSLfatal() already called */ return -1; } /* if we're renegotiating, then there may be buffered records */ if (dtls1_get_processed_record(s)) return 1; /* get something from the wire */ /* check if we have the header */ if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) || (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) { rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n); /* read timeout is handled by dtls1_read_bytes */ if (rret <= 0) { /* SSLfatal() already called if appropriate */ return rret; /* error or non-blocking */ } /* this packet contained a partial record, dump it */ if (RECORD_LAYER_get_packet_length(&s->rlayer) != DTLS1_RT_HEADER_LENGTH) { RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY); p = RECORD_LAYER_get_packet(&s->rlayer); if (s->msg_callback) s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); /* Pull apart the header into the DTLS1_RECORD */ rr->type = *(p++); ssl_major = *(p++); ssl_minor = *(p++); version = (ssl_major << 8) | ssl_minor; /* sequence number is 64 bits, with top 2 bytes = epoch */ n2s(p, rr->epoch); memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6); p += 6; n2s(p, rr->length); rr->read = 0; /* * Lets check the version. We tolerate alerts that don't have the exact * version number (e.g. because of protocol version errors) */ if (!s->first_packet && rr->type != SSL3_RT_ALERT) { if (version != s->version) { /* unexpected version, silently discard */ rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } } if ((version & 0xff00) != (s->version & 0xff00)) { /* wrong version, silently discard record */ rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { /* record too long, silently discard it */ rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } /* If received packet overflows own-client Max Fragment Length setting */ if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) && rr->length > GET_MAX_FRAGMENT_LENGTH(s->session) + SSL3_RT_MAX_ENCRYPTED_OVERHEAD) { /* record too long, silently discard it */ rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } /* now s->rlayer.rstate == SSL_ST_READ_BODY */ } /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */ if (rr->length > RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) { /* now s->rlayer.packet_length == DTLS1_RT_HEADER_LENGTH */ more = rr->length; rret = ssl3_read_n(s, more, more, 1, 1, &n); /* this packet contained a partial record, dump it */ if (rret <= 0 || n != more) { if (ossl_statem_in_error(s)) { /* ssl3_read_n() called SSLfatal() */ return -1; } rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } /* * now n == rr->length, and s->rlayer.packet_length == * DTLS1_RT_HEADER_LENGTH + rr->length */ } /* set state for later operations */ RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER); /* match epochs. NULL means the packet is dropped on the floor */ bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); if (bitmap == NULL) { rr->length = 0; RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ goto again; /* get another record */ } #ifndef OPENSSL_NO_SCTP /* Only do replay check if no SCTP bio */ if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) { #endif /* Check whether this is a repeat, or aged record. */ if (!dtls1_record_replay_check(s, bitmap)) { rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ goto again; /* get another record */ } #ifndef OPENSSL_NO_SCTP } #endif /* just read a 0 length packet */ if (rr->length == 0) { rr->read = 1; goto again; } /* * If this record is from the next epoch (either HM or ALERT), and a * handshake is currently in progress, buffer it since it cannot be * processed at this time. */ if (is_next_epoch) { if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) { if (dtls1_buffer_record (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)), rr->seq_num) < 0) { /* SSLfatal() already called */ return -1; } } rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); goto again; } if (!dtls1_process_record(s, bitmap)) { if (ossl_statem_in_error(s)) { /* dtls1_process_record() called SSLfatal */ return -1; } rr->length = 0; rr->read = 1; RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */ goto again; /* get another record */ } return 1; } int dtls_buffer_listen_record(SSL *s, size_t len, unsigned char *seq, size_t off) { SSL3_RECORD *rr; rr = RECORD_LAYER_get_rrec(&s->rlayer); memset(rr, 0, sizeof(SSL3_RECORD)); rr->length = len; rr->type = SSL3_RT_HANDSHAKE; memcpy(rr->seq_num, seq, sizeof(rr->seq_num)); rr->off = off; s->rlayer.packet = RECORD_LAYER_get_rbuf(&s->rlayer)->buf; s->rlayer.packet_length = DTLS1_RT_HEADER_LENGTH + len; rr->data = s->rlayer.packet + DTLS1_RT_HEADER_LENGTH; if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds), SSL3_RECORD_get_seq_num(s->rlayer.rrec)) <= 0) { /* SSLfatal() already called */ return 0; } return 1; }