66fab92316
The TLS code marks records as read when its finished using a record. The DTLS code did not do that. However SSL_has_pending() relies on it. So we should make DTLS consistent. Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/6159)
2022 lines
70 KiB
C
2022 lines
70 KiB
C
/*
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* Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include "../ssl_locl.h"
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#include "internal/constant_time_locl.h"
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#include <openssl/rand.h>
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#include "record_locl.h"
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#include "internal/cryptlib.h"
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static const unsigned char ssl3_pad_1[48] = {
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
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};
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static const unsigned char ssl3_pad_2[48] = {
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
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};
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/*
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* Clear the contents of an SSL3_RECORD but retain any memory allocated
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*/
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void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
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{
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unsigned char *comp;
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size_t i;
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for (i = 0; i < num_recs; i++) {
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comp = r[i].comp;
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memset(&r[i], 0, sizeof(*r));
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r[i].comp = comp;
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}
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}
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void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
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{
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size_t i;
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for (i = 0; i < num_recs; i++) {
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OPENSSL_free(r[i].comp);
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r[i].comp = NULL;
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}
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}
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void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
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{
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memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
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}
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/*
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* Peeks ahead into "read_ahead" data to see if we have a whole record waiting
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* for us in the buffer.
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*/
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static int ssl3_record_app_data_waiting(SSL *s)
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{
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SSL3_BUFFER *rbuf;
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size_t left, len;
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unsigned char *p;
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rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
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p = SSL3_BUFFER_get_buf(rbuf);
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if (p == NULL)
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return 0;
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left = SSL3_BUFFER_get_left(rbuf);
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if (left < SSL3_RT_HEADER_LENGTH)
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return 0;
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p += SSL3_BUFFER_get_offset(rbuf);
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/*
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* We only check the type and record length, we will sanity check version
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* etc later
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*/
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if (*p != SSL3_RT_APPLICATION_DATA)
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return 0;
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p += 3;
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n2s(p, len);
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if (left < SSL3_RT_HEADER_LENGTH + len)
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return 0;
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return 1;
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}
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int early_data_count_ok(SSL *s, size_t length, size_t overhead, int send)
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{
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uint32_t max_early_data = s->max_early_data;
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SSL_SESSION *sess = s->session;
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/*
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* If we are a client then we always use the max_early_data from the
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* session/psksession. Otherwise we go with the lowest out of the max early
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* data set in the session and the configured max_early_data.
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*/
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if (!s->server && sess->ext.max_early_data == 0) {
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if (!ossl_assert(s->psksession != NULL
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&& s->psksession->ext.max_early_data > 0)) {
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SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_EARLY_DATA_COUNT_OK,
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ERR_R_INTERNAL_ERROR);
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return 0;
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}
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sess = s->psksession;
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}
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if (!s->server
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|| (s->hit && sess->ext.max_early_data < s->max_early_data))
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max_early_data = sess->ext.max_early_data;
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if (max_early_data == 0) {
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SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
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SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
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return 0;
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}
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/* If we are dealing with ciphertext we need to allow for the overhead */
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max_early_data += overhead;
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if (s->early_data_count + length > max_early_data) {
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SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
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SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
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return 0;
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}
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s->early_data_count += length;
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return 1;
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}
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/*
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* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
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* will be processed per call to ssl3_get_record. Without this limit an
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* attacker could send empty records at a faster rate than we can process and
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* cause ssl3_get_record to loop forever.
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*/
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#define MAX_EMPTY_RECORDS 32
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#define SSL2_RT_HEADER_LENGTH 2
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/*-
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* Call this to get new input records.
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* It will return <= 0 if more data is needed, normally due to an error
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* or non-blocking IO.
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* When it finishes, |numrpipes| records have been decoded. For each record 'i':
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* rr[i].type - is the type of record
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* rr[i].data, - data
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* rr[i].length, - number of bytes
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* Multiple records will only be returned if the record types are all
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* SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
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* |max_pipelines|
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*/
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/* used only by ssl3_read_bytes */
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int ssl3_get_record(SSL *s)
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{
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int enc_err, rret;
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int i;
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size_t more, n;
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SSL3_RECORD *rr, *thisrr;
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SSL3_BUFFER *rbuf;
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SSL_SESSION *sess;
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unsigned char *p;
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unsigned char md[EVP_MAX_MD_SIZE];
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unsigned int version;
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size_t mac_size;
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int imac_size;
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size_t num_recs = 0, max_recs, j;
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PACKET pkt, sslv2pkt;
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size_t first_rec_len;
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rr = RECORD_LAYER_get_rrec(&s->rlayer);
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rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
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max_recs = s->max_pipelines;
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if (max_recs == 0)
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max_recs = 1;
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sess = s->session;
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do {
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thisrr = &rr[num_recs];
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/* check if we have the header */
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if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
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(RECORD_LAYER_get_packet_length(&s->rlayer)
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< SSL3_RT_HEADER_LENGTH)) {
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size_t sslv2len;
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unsigned int type;
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rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
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SSL3_BUFFER_get_len(rbuf), 0,
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num_recs == 0 ? 1 : 0, &n);
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if (rret <= 0)
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return rret; /* error or non-blocking */
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RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
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p = RECORD_LAYER_get_packet(&s->rlayer);
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if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
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RECORD_LAYER_get_packet_length(&s->rlayer))) {
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SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
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ERR_R_INTERNAL_ERROR);
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return -1;
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}
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sslv2pkt = pkt;
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if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
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|| !PACKET_get_1(&sslv2pkt, &type)) {
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SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
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ERR_R_INTERNAL_ERROR);
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return -1;
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}
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/*
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* The first record received by the server may be a V2ClientHello.
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*/
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if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
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&& (sslv2len & 0x8000) != 0
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&& (type == SSL2_MT_CLIENT_HELLO)) {
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/*
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* SSLv2 style record
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*
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* |num_recs| here will actually always be 0 because
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* |num_recs > 0| only ever occurs when we are processing
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* multiple app data records - which we know isn't the case here
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* because it is an SSLv2ClientHello. We keep it using
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* |num_recs| for the sake of consistency
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*/
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thisrr->type = SSL3_RT_HANDSHAKE;
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thisrr->rec_version = SSL2_VERSION;
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thisrr->length = sslv2len & 0x7fff;
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if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
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- SSL2_RT_HEADER_LENGTH) {
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SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
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SSL_R_PACKET_LENGTH_TOO_LONG);
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return -1;
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}
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if (thisrr->length < MIN_SSL2_RECORD_LEN) {
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SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
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SSL_R_LENGTH_TOO_SHORT);
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return -1;
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}
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} else {
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/* SSLv3+ style record */
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if (s->msg_callback)
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s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
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s->msg_callback_arg);
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/* Pull apart the header into the SSL3_RECORD */
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if (!PACKET_get_1(&pkt, &type)
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|| !PACKET_get_net_2(&pkt, &version)
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|| !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
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SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
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ERR_R_INTERNAL_ERROR);
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return -1;
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}
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thisrr->type = type;
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thisrr->rec_version = version;
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/*
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* Lets check version. In TLSv1.3 we only check this field
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* when encryption is occurring (see later check). For the
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* ServerHello after an HRR we haven't actually selected TLSv1.3
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* yet, but we still treat it as TLSv1.3, so we must check for
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* that explicitly
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*/
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if (!s->first_packet && !SSL_IS_TLS13(s)
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&& s->hello_retry_request != SSL_HRR_PENDING
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&& version != (unsigned int)s->version) {
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if ((s->version & 0xFF00) == (version & 0xFF00)
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&& !s->enc_write_ctx && !s->write_hash) {
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if (thisrr->type == SSL3_RT_ALERT) {
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/*
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* The record is using an incorrect version number,
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* but what we've got appears to be an alert. We
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* haven't read the body yet to check whether its a
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* fatal or not - but chances are it is. We probably
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* shouldn't send a fatal alert back. We'll just
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* end.
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*/
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SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
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SSL_R_WRONG_VERSION_NUMBER);
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return -1;
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}
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/*
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* Send back error using their minor version number :-)
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*/
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s->version = (unsigned short)version;
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}
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SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL3_GET_RECORD,
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SSL_R_WRONG_VERSION_NUMBER);
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return -1;
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}
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if ((version >> 8) != SSL3_VERSION_MAJOR) {
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if (RECORD_LAYER_is_first_record(&s->rlayer)) {
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/* Go back to start of packet, look at the five bytes
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* that we have. */
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p = RECORD_LAYER_get_packet(&s->rlayer);
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if (strncmp((char *)p, "GET ", 4) == 0 ||
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strncmp((char *)p, "POST ", 5) == 0 ||
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strncmp((char *)p, "HEAD ", 5) == 0 ||
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strncmp((char *)p, "PUT ", 4) == 0) {
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SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
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SSL_R_HTTP_REQUEST);
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return -1;
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} else if (strncmp((char *)p, "CONNE", 5) == 0) {
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SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
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SSL_R_HTTPS_PROXY_REQUEST);
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return -1;
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}
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/* Doesn't look like TLS - don't send an alert */
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SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
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SSL_R_WRONG_VERSION_NUMBER);
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return -1;
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} else {
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SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
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SSL_F_SSL3_GET_RECORD,
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SSL_R_WRONG_VERSION_NUMBER);
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return -1;
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}
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}
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if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
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if (thisrr->type != SSL3_RT_APPLICATION_DATA
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&& (thisrr->type != SSL3_RT_CHANGE_CIPHER_SPEC
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|| !SSL_IS_FIRST_HANDSHAKE(s))) {
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SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
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SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
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return -1;
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}
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if (thisrr->rec_version != TLS1_2_VERSION) {
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SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
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SSL_R_WRONG_VERSION_NUMBER);
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return -1;
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}
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}
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if (thisrr->length >
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SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
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SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
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SSL_R_PACKET_LENGTH_TOO_LONG);
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return -1;
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}
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}
|
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|
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/* now s->rlayer.rstate == SSL_ST_READ_BODY */
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}
|
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|
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if (SSL_IS_TLS13(s)) {
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if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
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SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
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SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
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return -1;
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}
|
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} else {
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size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
|
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|
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#ifndef OPENSSL_NO_COMP
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/*
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* If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
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* does not include the compression overhead anyway.
|
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*/
|
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if (s->expand == NULL)
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len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
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#endif
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|
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if (thisrr->length > len) {
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SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
|
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SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
|
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return -1;
|
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}
|
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}
|
|
|
|
/*
|
|
* 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
|
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* record
|
|
*/
|
|
if (thisrr->rec_version == SSL2_VERSION) {
|
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more = thisrr->length + SSL2_RT_HEADER_LENGTH
|
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- SSL3_RT_HEADER_LENGTH;
|
|
} else {
|
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more = thisrr->length;
|
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}
|
|
if (more > 0) {
|
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/* now s->packet_length == SSL3_RT_HEADER_LENGTH */
|
|
|
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rret = ssl3_read_n(s, more, more, 1, 0, &n);
|
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if (rret <= 0)
|
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return rret; /* error or non-blocking io */
|
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}
|
|
|
|
/* 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
|
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* + 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 =
|
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&(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
|
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} else {
|
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thisrr->input =
|
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&(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
|
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}
|
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|
|
/*
|
|
* 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
|
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* 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++;
|
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|
|
/* 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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
#ifdef SSL_DEBUG
|
|
printf("dec %lu\n", (unsigned long)rr[0].length);
|
|
{
|
|
size_t z;
|
|
for (z = 0; z < rr[0].length; z++)
|
|
printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
|
|
}
|
|
printf("\n");
|
|
#endif
|
|
|
|
/* 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;
|
|
}
|
|
|
|
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) {
|
|
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) {
|
|
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)) {
|
|
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);
|
|
|
|
#ifdef SSL_DEBUG
|
|
fprintf(stderr, "seq=");
|
|
{
|
|
int z;
|
|
for (z = 0; z < 8; z++)
|
|
fprintf(stderr, "%02X ", seq[z]);
|
|
fprintf(stderr, "\n");
|
|
}
|
|
fprintf(stderr, "rec=");
|
|
{
|
|
size_t z;
|
|
for (z = 0; z < rec->length; z++)
|
|
fprintf(stderr, "%02X ", rec->data[z]);
|
|
fprintf(stderr, "\n");
|
|
}
|
|
#endif
|
|
|
|
if (!SSL_IS_DTLS(ssl)) {
|
|
for (i = 7; i >= 0; i--) {
|
|
++seq[i];
|
|
if (seq[i] != 0)
|
|
break;
|
|
}
|
|
}
|
|
#ifdef SSL_DEBUG
|
|
{
|
|
unsigned int z;
|
|
for (z = 0; z < md_size; z++)
|
|
fprintf(stderr, "%02X ", md[z]);
|
|
fprintf(stderr, "\n");
|
|
}
|
|
#endif
|
|
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;
|
|
}
|
|
#ifdef SSL_DEBUG
|
|
printf("dec %ld\n", rr->length);
|
|
{
|
|
size_t z;
|
|
for (z = 0; z < rr->length; z++)
|
|
printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
|
|
}
|
|
printf("\n");
|
|
#endif
|
|
|
|
/* 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;
|
|
|
|
}
|