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- /*
- * Copyright 1995-2018 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 "internal/constant_time.h"
- #include <openssl/trace.h>
- #include <openssl/rand.h>
- #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, SSL_F_EARLY_DATA_COUNT_OK,
- 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_F_EARLY_DATA_COUNT_OK, 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_F_EARLY_DATA_COUNT_OK, 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;
- int imac_size;
- size_t num_recs = 0, max_recs, j;
- PACKET pkt, sslv2pkt;
- size_t first_rec_len;
- int is_ktls_left;
- rr = RECORD_LAYER_get_rrec(&s->rlayer);
- rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
- is_ktls_left = (rbuf->left > 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))
- return rret; /* error or non-blocking */
- switch (errno) {
- case EBADMSG:
- SSLfatal(s, SSL_AD_BAD_RECORD_MAC,
- SSL_F_SSL3_GET_RECORD,
- SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
- break;
- case EMSGSIZE:
- SSLfatal(s, SSL_AD_RECORD_OVERFLOW,
- SSL_F_SSL3_GET_RECORD,
- SSL_R_PACKET_LENGTH_TOO_LONG);
- break;
- case EINVAL:
- SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
- SSL_F_SSL3_GET_RECORD,
- 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, SSL_F_SSL3_GET_RECORD,
- 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, SSL_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- SSL_R_PACKET_LENGTH_TOO_LONG);
- return -1;
- }
- if (thisrr->length < MIN_SSL2_RECORD_LEN) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
- SSL_R_LENGTH_TOO_SHORT);
- return -1;
- }
- } else {
- /* SSLv3+ style record */
- if (s->msg_callback)
- s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
- s->msg_callback_arg);
- /* 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)) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- thisrr->type = type;
- thisrr->rec_version = version;
- /*
- * 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_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- 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 (strncmp((char *)p, "GET ", 4) == 0 ||
- strncmp((char *)p, "POST ", 5) == 0 ||
- strncmp((char *)p, "HEAD ", 5) == 0 ||
- strncmp((char *)p, "PUT ", 4) == 0) {
- SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
- SSL_R_HTTP_REQUEST);
- return -1;
- } else if (strncmp((char *)p, "CONNE", 5) == 0) {
- SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
- SSL_R_HTTPS_PROXY_REQUEST);
- return -1;
- }
- /* Doesn't look like TLS - don't send an alert */
- SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
- SSL_R_WRONG_VERSION_NUMBER);
- return -1;
- } else {
- SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
- SSL_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
- return -1;
- }
- if (thisrr->rec_version != TLS1_2_VERSION) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- 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
- if (thisrr->length > len && !BIO_get_ktls_recv(s->rbio)) {
- SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
- 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->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->packet_length == SSL3_RT_HEADER_LENGTH
- * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
- * + thisrr->length and we have that many bytes in s->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->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 pointed 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_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
- & EVP_CIPH_FLAG_PIPELINE)
- && 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_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- 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 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;
- /* TODO(size_t): convert this to do size_t properly */
- imac_size = EVP_MD_CTX_size(s->read_hash);
- if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
- ERR_LIB_EVP);
- return -1;
- }
- mac_size = (size_t)imac_size;
- for (j = 0; j < num_recs; j++) {
- thisrr = &rr[j];
- if (thisrr->length < mac_size) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
- 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_F_SSL3_GET_RECORD,
- SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
- return -1;
- }
- }
- }
- first_rec_len = rr[0].length;
- enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
- /*-
- * enc_err is:
- * 0: (in non-constant time) if the record is publicly invalid.
- * 1: if the padding is valid
- * -1: if the padding is invalid
- */
- if (enc_err == 0) {
- if (ossl_statem_in_error(s)) {
- /* SSLfatal() already got called */
- return -1;
- }
- if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
- /*
- * Valid early_data that we cannot decrypt might fail here as
- * publicly invalid. 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 */
- return -1;
- }
- thisrr->length = 0;
- thisrr->read = 1;
- RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
- RECORD_LAYER_reset_read_sequence(&s->rlayer);
- return 1;
- }
- SSLfatal(s, SSL_AD_DECRYPTION_FAILED, SSL_F_SSL3_GET_RECORD,
- SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
- return -1;
- }
- 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_md(s->read_hash) != NULL)) {
- /* s->read_hash != NULL => mac_size != -1 */
- unsigned char *mac = NULL;
- unsigned char mac_tmp[EVP_MAX_MD_SIZE];
- mac_size = EVP_MD_CTX_size(s->read_hash);
- if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- for (j = 0; j < num_recs; j++) {
- thisrr = &rr[j];
- /*
- * orig_len is the length of the record before any padding was
- * removed. This is public information, as is the MAC in use,
- * therefore we can safely process the record in a different amount
- * of time if it's too short to possibly contain a MAC.
- */
- if (thisrr->orig_len < mac_size ||
- /* CBC records must have a padding length byte too. */
- (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
- thisrr->orig_len < mac_size + 1)) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
- SSL_R_LENGTH_TOO_SHORT);
- return -1;
- }
- if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
- /*
- * We update the length so that the TLS header bytes can be
- * constructed correctly but we need to extract the MAC in
- * constant time from within the record, without leaking the
- * contents of the padding bytes.
- */
- mac = mac_tmp;
- if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- thisrr->length -= mac_size;
- } else {
- /*
- * In this case there's no padding, so |rec->orig_len| equals
- * |rec->length| and we checked that there's enough bytes for
- * |mac_size| above.
- */
- thisrr->length -= mac_size;
- mac = &thisrr->data[thisrr->length];
- }
- i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
- if (i == 0 || mac == NULL
- || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
- enc_err = -1;
- if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
- enc_err = -1;
- }
- }
- if (enc_err < 0) {
- if (ossl_statem_in_error(s)) {
- /* We already called SSLfatal() */
- return -1;
- }
- if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
- /*
- * We assume this is unreadable early_data - we treat it like an
- * empty record
- */
- /*
- * The record length may have been modified by the mac check above
- * so we use the previously saved value
- */
- if (!early_data_count_ok(s, first_rec_len,
- EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
- /* SSLfatal() already called */
- return -1;
- }
- thisrr = &rr[0];
- thisrr->length = 0;
- thisrr->read = 1;
- RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
- RECORD_LAYER_reset_read_sequence(&s->rlayer);
- return 1;
- }
- /*
- * 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_F_SSL3_GET_RECORD,
- SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
- return -1;
- }
- 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_F_SSL3_GET_RECORD,
- SSL_R_COMPRESSED_LENGTH_TOO_LONG);
- return -1;
- }
- if (!ssl3_do_uncompress(s, thisrr)) {
- SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
- SSL_R_BAD_DECOMPRESSION);
- return -1;
- }
- }
- 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_F_SSL3_GET_RECORD,
- SSL_R_BAD_RECORD_TYPE);
- return -1;
- }
- /* 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_F_SSL3_GET_RECORD,
- SSL_R_BAD_RECORD_TYPE);
- return -1;
- }
- 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_F_SSL3_GET_RECORD,
- SSL_R_BAD_LENGTH);
- return -1;
- }
- if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH && !BIO_get_ktls_recv(s->rbio)) {
- SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
- SSL_R_DATA_LENGTH_TOO_LONG);
- return -1;
- }
- /* If received packet overflows current Max Fragment Length setting */
- if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
- && thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)
- && !BIO_get_ktls_recv(s->rbio)) {
- SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
- SSL_R_DATA_LENGTH_TOO_LONG);
- return -1;
- }
- 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_F_SSL3_GET_RECORD,
- SSL_R_RECORD_TOO_SMALL);
- return -1;
- }
- } 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 */
- return -1;
- }
- }
- RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
- return 1;
- }
- 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;
- /* TODO(size_t): Convert this call */
- 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;
- /* TODO(size_t): Convert this call */
- 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|. 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's padding is valid / the encryption was successful.
- * -1: if the record's padding is invalid or, if sending, an internal error
- * occurred.
- */
- int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
- {
- SSL3_RECORD *rec;
- EVP_CIPHER_CTX *ds;
- size_t l, i;
- size_t bs, mac_size = 0;
- int imac_size;
- 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_cipher(s->enc_write_ctx);
- } else {
- ds = s->enc_read_ctx;
- if (s->enc_read_ctx == NULL)
- enc = NULL;
- else
- enc = EVP_CIPHER_CTX_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 {
- l = rec->length;
- /* TODO(size_t): Convert this call */
- bs = EVP_CIPHER_CTX_block_size(ds);
- /* COMPRESS */
- if ((bs != 1) && sending) {
- 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)
- return 0;
- /* otherwise, rec->length >= bs */
- }
- /* TODO(size_t): Convert this call */
- if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
- return -1;
- if (EVP_MD_CTX_md(s->read_hash) != NULL) {
- /* TODO(size_t): convert me */
- imac_size = EVP_MD_CTX_size(s->read_hash);
- if (imac_size < 0) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- mac_size = (size_t)imac_size;
- }
- if ((bs != 1) && !sending)
- return ssl3_cbc_remove_padding(rec, bs, mac_size);
- }
- return 1;
- }
- #define MAX_PADDING 256
- /*-
- * tls1_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's padding is valid / the encryption was successful.
- * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
- * an internal error occurred.
- */
- int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
- {
- 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, ret, tmpr;
- size_t bs, mac_size = 0, ctr, padnum, loop;
- unsigned char padval;
- int imac_size;
- const EVP_CIPHER *enc;
- if (n_recs == 0) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return 0;
- }
- if (sending) {
- if (EVP_MD_CTX_md(s->write_hash)) {
- int n = EVP_MD_CTX_size(s->write_hash);
- if (!ossl_assert(n >= 0)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- }
- ds = s->enc_write_ctx;
- if (s->enc_write_ctx == NULL)
- enc = NULL;
- else {
- int ivlen;
- enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
- /* For TLSv1.1 and later explicit IV */
- if (SSL_USE_EXPLICIT_IV(s)
- && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
- ivlen = EVP_CIPHER_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, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- }
- }
- }
- } else {
- if (EVP_MD_CTX_md(s->read_hash)) {
- int n = EVP_MD_CTX_size(s->read_hash);
- if (!ossl_assert(n >= 0)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- }
- ds = s->enc_read_ctx;
- if (s->enc_read_ctx == NULL)
- enc = NULL;
- else
- enc = EVP_CIPHER_CTX_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;
- }
- ret = 1;
- } else {
- bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
- if (n_recs > 1) {
- if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
- & EVP_CIPH_FLAG_PIPELINE)) {
- /*
- * We shouldn't have been called with pipeline data if the
- * cipher doesn't support pipelining
- */
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- SSL_R_PIPELINE_FAILURE);
- return -1;
- }
- }
- for (ctr = 0; ctr < n_recs; ctr++) {
- reclen[ctr] = recs[ctr].length;
- if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
- & EVP_CIPH_FLAG_AEAD_CIPHER) {
- 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[9], *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, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- if (sending) {
- reclen[ctr] += pad;
- recs[ctr].length += pad;
- }
- } else if ((bs != 1) && sending) {
- padnum = bs - (reclen[ctr] % bs);
- /* Add weird padding of upto 256 bytes */
- if (padnum > MAX_PADDING) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- /* 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)
- 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_F_TLS1_ENC,
- SSL_R_PIPELINE_FAILURE);
- return -1;
- }
- /* 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_F_TLS1_ENC,
- SSL_R_PIPELINE_FAILURE);
- return -1;
- }
- }
- /* TODO(size_t): Convert this call */
- tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
- (unsigned int)reclen[0]);
- if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
- & EVP_CIPH_FLAG_CUSTOM_CIPHER)
- ? (tmpr < 0)
- : (tmpr == 0))
- return -1; /* AEAD can fail to verify MAC */
- if (sending == 0) {
- if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
- for (ctr = 0; ctr < n_recs; ctr++) {
- 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_mode(enc) == EVP_CIPH_CCM_MODE) {
- for (ctr = 0; ctr < n_recs; ctr++) {
- 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;
- }
- }
- }
- ret = 1;
- if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
- imac_size = EVP_MD_CTX_size(s->read_hash);
- if (imac_size < 0) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
- ERR_R_INTERNAL_ERROR);
- return -1;
- }
- mac_size = (size_t)imac_size;
- }
- if ((bs != 1) && !sending) {
- int tmpret;
- for (ctr = 0; ctr < n_recs; ctr++) {
- tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
- /*
- * If tmpret == 0 then this means publicly invalid so we can
- * short circuit things here. Otherwise we must respect constant
- * time behaviour.
- */
- if (tmpret == 0)
- return 0;
- ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
- ret, -1);
- }
- }
- if (pad && !sending) {
- for (ctr = 0; ctr < n_recs; ctr++) {
- recs[ctr].length -= pad;
- }
- }
- }
- return ret;
- }
- 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_size(hash);
- if (t < 0)
- return 0;
- md_size = t;
- npad = (48 / md_size) * md_size;
- if (!sending &&
- EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
- ssl3_cbc_record_digest_supported(hash)) {
- /*
- * 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(hash,
- md, &md_size,
- header, rec->input,
- rec->length + md_size, rec->orig_len,
- mac_sec, md_size, 1) <= 0)
- return 0;
- } 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 t;
- 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_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)) {
- EVP_MD_CTX_free(hmac);
- return 0;
- }
- mac_ctx = hmac;
- }
- 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_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
- ssl3_cbc_record_digest_supported(mac_ctx)) {
- /*
- * 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.
- */
- /* Final param == not SSLv3 */
- if (ssl3_cbc_digest_record(mac_ctx,
- md, &md_size,
- header, rec->input,
- rec->length + md_size, rec->orig_len,
- ssl->s3.read_mac_secret,
- ssl->s3.read_mac_secret_size, 0) <= 0) {
- EVP_MD_CTX_free(hmac);
- return 0;
- }
- } else {
- /* TODO(size_t): Convert these calls */
- 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) {
- EVP_MD_CTX_free(hmac);
- return 0;
- }
- }
- EVP_MD_CTX_free(hmac);
- 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);
- return 1;
- }
- /*-
- * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
- * record in |rec| by updating |rec->length| in constant time.
- *
- * block_size: the block size of the cipher used to encrypt the record.
- * returns:
- * 0: (in non-constant time) if the record is publicly invalid.
- * 1: if the padding was valid
- * -1: otherwise.
- */
- int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
- size_t block_size, size_t mac_size)
- {
- size_t padding_length;
- size_t good;
- const size_t overhead = 1 /* padding length byte */ + mac_size;
- /*
- * These lengths are all public so we can test them in non-constant time.
- */
- if (overhead > rec->length)
- return 0;
- padding_length = rec->data[rec->length - 1];
- good = constant_time_ge_s(rec->length, padding_length + overhead);
- /* SSLv3 requires that the padding is minimal. */
- good &= constant_time_ge_s(block_size, padding_length + 1);
- rec->length -= good & (padding_length + 1);
- return constant_time_select_int_s(good, 1, -1);
- }
- /*-
- * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
- * record in |rec| in constant time and returns 1 if the padding is valid and
- * -1 otherwise. It also removes any explicit IV from the start of the record
- * without leaking any timing about whether there was enough space after the
- * padding was removed.
- *
- * block_size: the block size of the cipher used to encrypt the record.
- * returns:
- * 0: (in non-constant time) if the record is publicly invalid.
- * 1: if the padding was valid
- * -1: otherwise.
- */
- int tls1_cbc_remove_padding(const SSL *s,
- SSL3_RECORD *rec,
- size_t block_size, size_t mac_size)
- {
- size_t good;
- size_t padding_length, to_check, i;
- const size_t overhead = 1 /* padding length byte */ + mac_size;
- /* Check if version requires explicit IV */
- if (SSL_USE_EXPLICIT_IV(s)) {
- /*
- * These lengths are all public so we can test them in non-constant
- * time.
- */
- if (overhead + block_size > rec->length)
- return 0;
- /* We can now safely skip explicit IV */
- rec->data += block_size;
- rec->input += block_size;
- rec->length -= block_size;
- rec->orig_len -= block_size;
- } else if (overhead > rec->length)
- return 0;
- padding_length = rec->data[rec->length - 1];
- if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
- EVP_CIPH_FLAG_AEAD_CIPHER) {
- /* padding is already verified */
- rec->length -= padding_length + 1;
- return 1;
- }
- good = constant_time_ge_s(rec->length, overhead + padding_length);
- /*
- * The padding consists of a length byte at the end of the record and
- * then that many bytes of padding, all with the same value as the length
- * byte. Thus, with the length byte included, there are i+1 bytes of
- * padding. We can't check just |padding_length+1| bytes because that
- * leaks decrypted information. Therefore we always have to check the
- * maximum amount of padding possible. (Again, the length of the record
- * is public information so we can use it.)
- */
- to_check = 256; /* maximum amount of padding, inc length byte. */
- if (to_check > rec->length)
- to_check = rec->length;
- for (i = 0; i < to_check; i++) {
- unsigned char mask = constant_time_ge_8_s(padding_length, i);
- unsigned char b = rec->data[rec->length - 1 - i];
- /*
- * The final |padding_length+1| bytes should all have the value
- * |padding_length|. Therefore the XOR should be zero.
- */
- good &= ~(mask & (padding_length ^ b));
- }
- /*
- * If any of the final |padding_length+1| bytes had the wrong value, one
- * or more of the lower eight bits of |good| will be cleared.
- */
- good = constant_time_eq_s(0xff, good & 0xff);
- rec->length -= good & (padding_length + 1);
- return constant_time_select_int_s(good, 1, -1);
- }
- /*-
- * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
- * constant time (independent of the concrete value of rec->length, which may
- * vary within a 256-byte window).
- *
- * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
- * this function.
- *
- * On entry:
- * rec->orig_len >= md_size
- * md_size <= EVP_MAX_MD_SIZE
- *
- * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
- * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
- * a single or pair of cache-lines, then the variable memory accesses don't
- * actually affect the timing. CPUs with smaller cache-lines [if any] are
- * not multi-core and are not considered vulnerable to cache-timing attacks.
- */
- #define CBC_MAC_ROTATE_IN_PLACE
- int ssl3_cbc_copy_mac(unsigned char *out,
- const SSL3_RECORD *rec, size_t md_size)
- {
- #if defined(CBC_MAC_ROTATE_IN_PLACE)
- unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
- unsigned char *rotated_mac;
- #else
- unsigned char rotated_mac[EVP_MAX_MD_SIZE];
- #endif
- /*
- * mac_end is the index of |rec->data| just after the end of the MAC.
- */
- size_t mac_end = rec->length;
- size_t mac_start = mac_end - md_size;
- size_t in_mac;
- /*
- * scan_start contains the number of bytes that we can ignore because the
- * MAC's position can only vary by 255 bytes.
- */
- size_t scan_start = 0;
- size_t i, j;
- size_t rotate_offset;
- if (!ossl_assert(rec->orig_len >= md_size
- && md_size <= EVP_MAX_MD_SIZE))
- return 0;
- #if defined(CBC_MAC_ROTATE_IN_PLACE)
- rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
- #endif
- /* This information is public so it's safe to branch based on it. */
- if (rec->orig_len > md_size + 255 + 1)
- scan_start = rec->orig_len - (md_size + 255 + 1);
- in_mac = 0;
- rotate_offset = 0;
- memset(rotated_mac, 0, md_size);
- for (i = scan_start, j = 0; i < rec->orig_len; i++) {
- size_t mac_started = constant_time_eq_s(i, mac_start);
- size_t mac_ended = constant_time_lt_s(i, mac_end);
- unsigned char b = rec->data[i];
- in_mac |= mac_started;
- in_mac &= mac_ended;
- rotate_offset |= j & mac_started;
- rotated_mac[j++] |= b & in_mac;
- j &= constant_time_lt_s(j, md_size);
- }
- /* Now rotate the MAC */
- #if defined(CBC_MAC_ROTATE_IN_PLACE)
- j = 0;
- for (i = 0; i < md_size; i++) {
- /* in case cache-line is 32 bytes, touch second line */
- ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
- out[j++] = rotated_mac[rotate_offset++];
- rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
- }
- #else
- memset(out, 0, md_size);
- rotate_offset = md_size - rotate_offset;
- rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
- for (i = 0; i < md_size; i++) {
- for (j = 0; j < md_size; j++)
- out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
- rotate_offset++;
- rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
- }
- #endif
- return 1;
- }
- 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;
- unsigned char md[EVP_MAX_MD_SIZE];
- rr = RECORD_LAYER_get_rrec(&s->rlayer);
- sess = s->session;
- /*
- * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
- * and we have that many bytes in s->packet
- */
- rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
- /*
- * ok, we can now read from 's->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_F_DTLS1_PROCESS_RECORD,
- SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
- return 0;
- }
- /* decrypt in place in 'rr->input' */
- rr->data = rr->input;
- rr->orig_len = rr->length;
- if (SSL_READ_ETM(s) && s->read_hash) {
- unsigned char *mac;
- mac_size = EVP_MD_CTX_size(s->read_hash);
- if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- ERR_R_INTERNAL_ERROR);
- return 0;
- }
- if (rr->orig_len < mac_size) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- 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_F_DTLS1_PROCESS_RECORD,
- SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
- return 0;
- }
- }
- enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
- /*-
- * enc_err is:
- * 0: (in non-constant time) if the record is publically invalid.
- * 1: if the padding is valid
- * -1: if the padding is invalid
- */
- if (enc_err == 0) {
- if (ossl_statem_in_error(s)) {
- /* SSLfatal() got called */
- return 0;
- }
- /* For DTLS we simply ignore bad packets. */
- rr->length = 0;
- RECORD_LAYER_reset_packet_length(&s->rlayer);
- return 0;
- }
- 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_md(s->read_hash) != NULL)) {
- /* s->read_hash != NULL => mac_size != -1 */
- unsigned char *mac = NULL;
- unsigned char mac_tmp[EVP_MAX_MD_SIZE];
- /* TODO(size_t): Convert this to do size_t properly */
- imac_size = EVP_MD_CTX_size(s->read_hash);
- if (imac_size < 0) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- ERR_LIB_EVP);
- return 0;
- }
- mac_size = (size_t)imac_size;
- if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- ERR_R_INTERNAL_ERROR);
- return 0;
- }
- /*
- * orig_len is the length of the record before any padding was
- * removed. This is public information, as is the MAC in use,
- * therefore we can safely process the record in a different amount
- * of time if it's too short to possibly contain a MAC.
- */
- if (rr->orig_len < mac_size ||
- /* CBC records must have a padding length byte too. */
- (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
- rr->orig_len < mac_size + 1)) {
- SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- SSL_R_LENGTH_TOO_SHORT);
- return 0;
- }
- if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
- /*
- * We update the length so that the TLS header bytes can be
- * constructed correctly but we need to extract the MAC in
- * constant time from within the record, without leaking the
- * contents of the padding bytes.
- */
- mac = mac_tmp;
- if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
- SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
- ERR_R_INTERNAL_ERROR);
- return 0;
- }
- rr->length -= mac_size;
- } else {
- /*
- * In this case there's no padding, so |rec->orig_len| equals
- * |rec->length| and we checked that there's enough bytes for
- * |mac_size| above.
- */
- rr->length -= mac_size;
- mac = &rr->data[rr->length];
- }
- i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
- if (i == 0 || mac == NULL
- || CRYPTO_memcmp(md, mac, mac_size) != 0)
- enc_err = -1;
- if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
- enc_err = -1;
- }
- if (enc_err < 0) {
- /* decryption failed, silently discard message */
- rr->length = 0;
- RECORD_LAYER_reset_packet_length(&s->rlayer);
- return 0;
- }
- /* 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_F_DTLS1_PROCESS_RECORD,
- SSL_R_COMPRESSED_LENGTH_TOO_LONG);
- return 0;
- }
- if (!ssl3_do_uncompress(s, rr)) {
- SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE,
- SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
- return 0;
- }
- }
- if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
- SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
- SSL_R_DATA_LENGTH_TOO_LONG);
- return 0;
- }
- 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);
- return 1;
- }
- /*
- * 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)) {
- /* 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->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->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. */
- /*
- * TODO: Does it make sense to have replay protection in epoch 0 where
- * we have no integrity negotiated yet?
- */
- 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;
- }
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