-/* ssl/record/ssl3_record.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
+/*
+ * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.]
+ * Licensed under the OpenSSL license (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
*/
-/* ====================================================================
- * Copyright (c) 1998-2015 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
+
+#include "../ssl_locl.h"
+#include "internal/constant_time_locl.h"
+#include <openssl/rand.h>
+#include "record_locl.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, unsigned int num_recs)
+{
+ unsigned char *comp;
+ unsigned int 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, unsigned int num_recs)
+{
+ unsigned int 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;
+ int 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;
+}
+
+/*
+ * 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 ssl_major, ssl_minor, al;
+ int enc_err, n, i, ret = -1;
+ SSL3_RECORD *rr;
+ SSL3_BUFFER *rbuf;
+ SSL_SESSION *sess;
+ unsigned char *p;
+ unsigned char md[EVP_MAX_MD_SIZE];
+ short version;
+ unsigned mac_size;
+ unsigned int num_recs = 0;
+ unsigned int max_recs;
+ unsigned int j;
+
+ rr = RECORD_LAYER_get_rrec(&s->rlayer);
+ rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
+ max_recs = s->max_pipelines;
+ if (max_recs == 0)
+ max_recs = 1;
+ sess = s->session;
+
+ do {
+ /* 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)) {
+ n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
+ SSL3_BUFFER_get_len(rbuf), 0, num_recs == 0 ? 1 : 0);
+ if (n <= 0)
+ return (n); /* error or non-blocking */
+ RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
+
+ p = RECORD_LAYER_get_packet(&s->rlayer);
+
+ /*
+ * The first record received by the server may be a V2ClientHello.
+ */
+ if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
+ && (p[0] & 0x80) && (p[2] == 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
+ */
+ rr[num_recs].type = SSL3_RT_HANDSHAKE;
+ rr[num_recs].rec_version = SSL2_VERSION;
+
+ rr[num_recs].length = ((p[0] & 0x7f) << 8) | p[1];
+
+ if (rr[num_recs].length > SSL3_BUFFER_get_len(rbuf)
+ - SSL2_RT_HEADER_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+
+ if (rr[num_recs].length < MIN_SSL2_RECORD_LEN) {
+ al = SSL_AD_HANDSHAKE_FAILURE;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
+ goto f_err;
+ }
+ } 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 */
+ rr[num_recs].type = *(p++);
+ ssl_major = *(p++);
+ ssl_minor = *(p++);
+ version = (ssl_major << 8) | ssl_minor;
+ rr[num_recs].rec_version = version;
+ n2s(p, rr[num_recs].length);
+
+ /* Lets check version */
+ if (!s->first_packet && version != s->version) {
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
+ if ((s->version & 0xFF00) == (version & 0xFF00)
+ && !s->enc_write_ctx && !s->write_hash) {
+ if (rr->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.
+ */
+ goto err;
+ }
+ /*
+ * Send back error using their minor version number :-)
+ */
+ s->version = (unsigned short)version;
+ }
+ al = SSL_AD_PROTOCOL_VERSION;
+ goto f_err;
+ }
+
+ 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) {
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST);
+ goto err;
+ } else if (strncmp((char *)p, "CONNE", 5) == 0) {
+ SSLerr(SSL_F_SSL3_GET_RECORD,
+ SSL_R_HTTPS_PROXY_REQUEST);
+ goto err;
+ }
+
+ /* Doesn't look like TLS - don't send an alert */
+ SSLerr(SSL_F_SSL3_GET_RECORD,
+ SSL_R_WRONG_VERSION_NUMBER);
+ goto err;
+ } else {
+ SSLerr(SSL_F_SSL3_GET_RECORD,
+ SSL_R_WRONG_VERSION_NUMBER);
+ al = SSL_AD_PROTOCOL_VERSION;
+ goto f_err;
+ }
+ }
+
+ if (rr[num_recs].length >
+ SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+ }
+
+ /* now s->rlayer.rstate == SSL_ST_READ_BODY */
+ }
+
+ /*
+ * 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 (rr[num_recs].rec_version == SSL2_VERSION) {
+ i = rr[num_recs].length + SSL2_RT_HEADER_LENGTH
+ - SSL3_RT_HEADER_LENGTH;
+ } else {
+ i = rr[num_recs].length;
+ }
+ if (i > 0) {
+ /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
+
+ n = ssl3_read_n(s, i, i, 1, 0);
+ if (n <= 0)
+ return (n); /* 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 + rr->length,
+ * or s->packet_length == SSL2_RT_HEADER_LENGTH + rr->length
+ * and we have that many bytes in s->packet
+ */
+ if (rr[num_recs].rec_version == SSL2_VERSION) {
+ rr[num_recs].input =
+ &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
+ } else {
+ rr[num_recs].input =
+ &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_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[num_recs].length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+
+ /* decrypt in place in 'rr->input' */
+ rr[num_recs].data = rr[num_recs].input;
+ rr[num_recs].orig_len = rr[num_recs].length;
+
+ /* Mark this record as not read by upper layers yet */
+ rr[num_recs].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
+ && rr[num_recs-1].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 in encrypt-then-mac mode calculate mac from encrypted record. All
+ * the details below are public so no timing details can leak.
+ */
+ if (SSL_USE_ETM(s) && s->read_hash) {
+ unsigned char *mac;
+ mac_size = EVP_MD_CTX_size(s->read_hash);
+ OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+ for (j = 0; j < num_recs; j++) {
+ if (rr[j].length < mac_size) {
+ al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
+ goto f_err;
+ }
+ rr[j].length -= mac_size;
+ mac = rr[j].data + rr[j].length;
+ i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ );
+ if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
+ al = SSL_AD_BAD_RECORD_MAC;
+ SSLerr(SSL_F_SSL3_GET_RECORD,
+ SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
+ goto f_err;
+ }
+ }
+ }
+
+ enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 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) {
+ al = SSL_AD_DECRYPTION_FAILED;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
+ goto f_err;
+ }
+#ifdef SSL_DEBUG
+ printf("dec %d\n", rr->length);
+ {
+ unsigned int 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) &&
+ (s->enc_read_ctx != NULL) &&
+ (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) {
+ /* 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);
+ OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+ for (j=0; j < num_recs; 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 (rr[j].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[j].orig_len < mac_size + 1)) {
+ al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
+ goto f_err;
+ }
+
+ 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;
+ ssl3_cbc_copy_mac(mac_tmp, &rr[j], mac_size);
+ rr[j].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[j].length -= mac_size;
+ mac = &rr[j].data[rr[j].length];
+ }
+
+ i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ );
+ if (i < 0 || mac == NULL
+ || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
+ enc_err = -1;
+ if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
+ enc_err = -1;
+ }
+ }
+
+ if (enc_err < 0) {
+ /*
+ * 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)
+ */
+ al = SSL_AD_BAD_RECORD_MAC;
+ SSLerr(SSL_F_SSL3_GET_RECORD,
+ SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
+ goto f_err;
+ }
+
+ for (j = 0; j < num_recs; j++) {
+ /* rr[j].length is now just compressed */
+ if (s->expand != NULL) {
+ if (rr[j].length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+ if (!ssl3_do_uncompress(s, &rr[j])) {
+ al = SSL_AD_DECOMPRESSION_FAILURE;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
+ goto f_err;
+ }
+ }
+
+ if (rr[j].length > SSL3_RT_MAX_PLAIN_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+
+ rr[j].off = 0;
+ /*-
+ * So at this point the following is true
+ * rr[j].type is the type of record
+ * rr[j].length == number of bytes in record
+ * rr[j].off == offset to first valid byte
+ * rr[j].data == where to take bytes from, increment after use :-).
+ */
+
+ /* just read a 0 length packet */
+ if (rr[j].length == 0) {
+ RECORD_LAYER_inc_empty_record_count(&s->rlayer);
+ if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
+ > MAX_EMPTY_RECORDS) {
+ al = SSL_AD_UNEXPECTED_MESSAGE;
+ SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
+ goto f_err;
+ }
+ } else {
+ RECORD_LAYER_reset_empty_record_count(&s->rlayer);
+ }
+ }
+
+ RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
+ return 1;
+
+ f_err:
+ ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ err:
+ return ret;
+}
+
+int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
+{
+#ifndef OPENSSL_NO_COMP
+ int i;
+
+ if (rr->comp == NULL) {
+ rr->comp = (unsigned char *)
+ OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
+ }
+ if (rr->comp == NULL)
+ return 0;
+
+ i = COMP_expand_block(ssl->expand, rr->comp,
+ SSL3_RT_MAX_PLAIN_LENGTH, rr->data,
+ (int)rr->length);
+ if (i < 0)
+ return 0;
+ else
+ rr->length = i;
+ rr->data = rr->comp;
+#endif
+ return 1;
+}
+
+int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
+{
+#ifndef OPENSSL_NO_COMP
+ int i;
+
+ i = COMP_compress_block(ssl->compress, wr->data,
+ SSL3_RT_MAX_COMPRESSED_LENGTH,
+ 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|
*
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ * 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, unsigned int n_recs, int send)
+{
+ SSL3_RECORD *rec;
+ EVP_CIPHER_CTX *ds;
+ unsigned long l;
+ int bs, i, mac_size = 0;
+ 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 (send) {
+ 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;
+ bs = EVP_CIPHER_CTX_block_size(ds);
+
+ /* COMPRESS */
+
+ if ((bs != 1) && send) {
+ i = bs - ((int)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] = (i - 1);
+ }
+
+ if (!send) {
+ if (l == 0 || l % bs != 0)
+ return 0;
+ /* otherwise, rec->length >= bs */
+ }
+
+ if (EVP_Cipher(ds, rec->data, rec->input, l) < 1)
+ return -1;
+
+ if (EVP_MD_CTX_md(s->read_hash) != NULL)
+ mac_size = EVP_MD_CTX_size(s->read_hash);
+ if ((bs != 1) && !send)
+ return ssl3_cbc_remove_padding(rec, bs, mac_size);
+ }
+ return (1);
+}
+
+/*-
+ * tls1_enc encrypts/decrypts |n_recs| in |recs|.
*
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@openssl.org.
+ * 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, unsigned int n_recs, int send)
+{
+ EVP_CIPHER_CTX *ds;
+ size_t reclen[SSL_MAX_PIPELINES];
+ unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
+ int bs, i, j, k, pad = 0, ret, mac_size = 0;
+ const EVP_CIPHER *enc;
+ unsigned int ctr;
+
+ if (send) {
+ if (EVP_MD_CTX_md(s->write_hash)) {
+ int n = EVP_MD_CTX_size(s->write_hash);
+ OPENSSL_assert(n >= 0);
+ }
+ 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)
+ */
+ SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
+ return -1;
+ } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
+ SSLerr(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);
+ OPENSSL_assert(n >= 0);
+ }
+ 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
+ */
+ SSLerr(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 = send ? 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(send ? 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] = recs[ctr].length >> 8;
+ buf[ctr][12] = 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)
+ return -1;
+
+ if (send) {
+ reclen[ctr] += pad;
+ recs[ctr].length += pad;
+ }
+
+ } else if ((bs != 1) && send) {
+ i = bs - ((int)reclen[ctr] % bs);
+
+ /* Add weird padding of upto 256 bytes */
+
+ /* we need to add 'i' padding bytes of value j */
+ j = i - 1;
+ for (k = (int)reclen[ctr]; k < (int)(reclen[ctr] + i); k++)
+ recs[ctr].input[k] = j;
+ reclen[ctr] += i;
+ recs[ctr].length += i;
+ }
+
+ if (!send) {
+ 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,
+ n_recs, data) <= 0) {
+ SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
+ }
+ /* 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,
+ n_recs, data) <= 0
+ || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
+ n_recs, reclen) <= 0) {
+ SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
+ return -1;
+ }
+ }
+
+ i = EVP_Cipher(ds, recs[0].data, recs[0].input, reclen[0]);
+ if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
+ & EVP_CIPH_FLAG_CUSTOM_CIPHER)
+ ? (i < 0)
+ : (i == 0))
+ return -1; /* AEAD can fail to verify MAC */
+ if (send == 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_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)
+ mac_size = EVP_MD_CTX_size(s->read_hash);
+ if ((bs != 1) && !send) {
+ 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 && !send) {
+ 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 send)
+{
+ unsigned char *mac_sec, *seq;
+ const EVP_MD_CTX *hash;
+ unsigned char *p, rec_char;
+ size_t md_size;
+ int npad;
+ int t;
+
+ if (send) {
+ 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 -1;
+ md_size = t;
+ npad = (48 / md_size) * md_size;
+
+ if (!send &&
+ 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];
+ unsigned 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++] = rec->length >> 8;
+ header[j++] = 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 -1;
+ } 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 -1;
+
+ 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_reset(md_ctx);
+ return -1;
+ }
+ md_size = md_size_u;
+
+ EVP_MD_CTX_free(md_ctx);
+ }
+
+ ssl3_record_sequence_update(seq);
+ return (md_size);
+}
+
+int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send)
+{
+ 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 = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
+ : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
+ int t;
+
+ if (send) {
+ 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);
+ OPENSSL_assert(t >= 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))
+ return -1;
+ mac_ctx = hmac;
+ }
+
+ if (SSL_IS_DTLS(ssl)) {
+ unsigned char dtlsseq[8], *p = dtlsseq;
+
+ s2n(send ? 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] = (rec->length) >> 8;
+ header[12] = (rec->length) & 0xff;
+
+ if (!send && !SSL_USE_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 -1;
+ }
+ } else {
+ 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 -1;
+ }
+ if (!send && !SSL_USE_ETM(ssl) && FIPS_mode())
+ if (!tls_fips_digest_extra(ssl->enc_read_ctx,
+ mac_ctx, rec->input,
+ rec->length, rec->orig_len)) {
+ EVP_MD_CTX_free(hmac);
+ return -1;
+ }
+ }
+
+ 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=");
+ {
+ unsigned int 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 (md_size);
+}
+
+/*-
+ * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
+ * record in |rec| by updating |rec->length| in constant time.
*
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
+ * 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,
+ unsigned block_size, unsigned mac_size)
+{
+ unsigned padding_length, good;
+ const unsigned 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(rec->length, padding_length + overhead);
+ /* SSLv3 requires that the padding is minimal. */
+ good &= constant_time_ge(block_size, padding_length + 1);
+ rec->length -= good & (padding_length + 1);
+ return constant_time_select_int(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.
*
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ * 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,
+ unsigned block_size, unsigned mac_size)
+{
+ unsigned padding_length, good, to_check, i;
+ const unsigned 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(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(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(0xff, good & 0xff);
+ rec->length -= good & (padding_length + 1);
+
+ return constant_time_select_int(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).
*
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
+ * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
+ * this function.
*
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
+ * 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
-#include "../ssl_locl.h"
-
-void SSL3_RECORD_clear(SSL3_RECORD *r)
+void ssl3_cbc_copy_mac(unsigned char *out,
+ const SSL3_RECORD *rec, unsigned md_size)
{
- memset(r->seq_num, 0, sizeof(r->seq_num));
-}
+#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
-void SSL3_RECORD_release(SSL3_RECORD *r)
-{
- if (r->comp != NULL)
- OPENSSL_free(r->comp);
- r->comp = NULL;
+ /*
+ * mac_end is the index of |rec->data| just after the end of the MAC.
+ */
+ unsigned mac_end = rec->length;
+ unsigned mac_start = mac_end - md_size;
+ /*
+ * scan_start contains the number of bytes that we can ignore because the
+ * MAC's position can only vary by 255 bytes.
+ */
+ unsigned scan_start = 0;
+ unsigned i, j;
+ unsigned div_spoiler;
+ unsigned rotate_offset;
+
+ OPENSSL_assert(rec->orig_len >= md_size);
+ OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
+
+#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);
+ /*
+ * div_spoiler contains a multiple of md_size that is used to cause the
+ * modulo operation to be constant time. Without this, the time varies
+ * based on the amount of padding when running on Intel chips at least.
+ * The aim of right-shifting md_size is so that the compiler doesn't
+ * figure out that it can remove div_spoiler as that would require it to
+ * prove that md_size is always even, which I hope is beyond it.
+ */
+ div_spoiler = md_size >> 1;
+ div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
+ rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
+
+ memset(rotated_mac, 0, md_size);
+ for (i = scan_start, j = 0; i < rec->orig_len; i++) {
+ unsigned char mac_started = constant_time_ge_8(i, mac_start);
+ unsigned char mac_ended = constant_time_ge_8(i, mac_end);
+ unsigned char b = rec->data[i];
+ rotated_mac[j++] |= b & mac_started & ~mac_ended;
+ j &= constant_time_lt(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(rotate_offset, md_size);
+ }
+#else
+ memset(out, 0, md_size);
+ rotate_offset = md_size - rotate_offset;
+ rotate_offset &= constant_time_lt(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(j, rotate_offset);
+ rotate_offset++;
+ rotate_offset &= constant_time_lt(rotate_offset, md_size);
+ }
+#endif
}
-int SSL3_RECORD_setup(SSL3_RECORD *r, size_t len)
+int dtls1_process_record(SSL *s)
{
- if (r->comp == NULL)
- r->comp = (unsigned char *) OPENSSL_malloc(len);
- if (r->comp == NULL)
- return 0;
- return 1;
+ int i, al;
+ int enc_err;
+ SSL_SESSION *sess;
+ SSL3_RECORD *rr;
+ unsigned int 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) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+
+ /* decrypt in place in 'rr->input' */
+ rr->data = rr->input;
+ rr->orig_len = rr->length;
+
+ 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) {
+ /* For DTLS we simply ignore bad packets. */
+ rr->length = 0;
+ RECORD_LAYER_reset_packet_length(&s->rlayer);
+ goto err;
+ }
+#ifdef SSL_DEBUG
+ printf("dec %d\n", rr->length);
+ {
+ unsigned int 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) &&
+ (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];
+ mac_size = EVP_MD_CTX_size(s->read_hash);
+ OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+ /*
+ * 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)) {
+ al = SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
+ goto f_err;
+ }
+
+ 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;
+ ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
+ 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, (size_t)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);
+ goto err;
+ }
+
+ /* r->length is now just compressed */
+ if (s->expand != NULL) {
+ if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
+ SSL_R_COMPRESSED_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+ if (!ssl3_do_uncompress(s, rr)) {
+ al = SSL_AD_DECOMPRESSION_FAILURE;
+ SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
+ goto f_err;
+ }
+ }
+
+ if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
+ al = SSL_AD_RECORD_OVERFLOW;
+ SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
+ goto f_err;
+ }
+
+ 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);
+ return (1);
+
+ f_err:
+ ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ err:
+ return (0);
}
-void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
+
+/*
+ * retrieve a buffered record that belongs to the current epoch, ie,
+ * 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)
{
- memcpy(r->seq_num, seq_num, 8);
+ int ssl_major, ssl_minor;
+ int i, 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);
+
+ /*
+ * The epoch may have changed. If so, process all the pending records.
+ * This is a non-blocking operation.
+ */
+ if (dtls1_process_buffered_records(s) < 0)
+ 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 */
+ again:
+ /* 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)) {
+ n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
+ SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1);
+ /* read timeout is handled by dtls1_read_bytes */
+ if (n <= 0)
+ return (n); /* 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);
+
+ /* Lets check version */
+ if (!s->first_packet) {
+ if (version != s->version) {
+ /* unexpected version, silently discard */
+ rr->length = 0;
+ RECORD_LAYER_reset_packet_length(&s->rlayer);
+ goto again;
+ }
+ }
+
+ if ((version & 0xff00) != (s->version & 0xff00)) {
+ /* wrong version, silently discard record */
+ rr->length = 0;
+ 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;
+ 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 */
+ i = rr->length;
+ n = ssl3_read_n(s, i, i, 1, 1);
+ /* this packet contained a partial record, dump it */
+ if (n != i) {
+ rr->length = 0;
+ 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. */
+ if (!dtls1_record_replay_check(s, bitmap)) {
+ rr->length = 0;
+ 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)
+ 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)
+ return -1;
+ /* Mark receipt of record. */
+ dtls1_record_bitmap_update(s, bitmap);
+ }
+ rr->length = 0;
+ RECORD_LAYER_reset_packet_length(&s->rlayer);
+ goto again;
+ }
+
+ if (!dtls1_process_record(s)) {
+ rr->length = 0;
+ RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
+ goto again; /* get another record */
+ }
+ dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */
+
+ return (1);
+
}
projects / openssl.git / blobdiff