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- /* ssl/record/ssl3_record.c */
- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * 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.]
- */
- /* ====================================================================
- * 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.
- *
- * 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/)"
- *
- * 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.
- *
- * 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.
- *
- * 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/)"
- *
- * 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.
- * ====================================================================
- *
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
- *
- */
- #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 char *comp = r->comp;
- memset(r, 0, sizeof(*r));
- r->comp = comp;
- }
- void SSL3_RECORD_release(SSL3_RECORD *r)
- {
- OPENSSL_free(r->comp);
- r->comp = NULL;
- }
- int SSL3_RECORD_setup(SSL3_RECORD *r)
- {
- if (r->comp == NULL)
- r->comp = (unsigned char *)
- OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
- if (r->comp == NULL)
- return 0;
- return 1;
- }
- void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
- {
- memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
- }
- /*
- * 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 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 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;
- SSL_SESSION *sess;
- unsigned char *p;
- unsigned char md[EVP_MAX_MD_SIZE];
- short version;
- unsigned mac_size;
- unsigned empty_record_count = 0;
- rr = RECORD_LAYER_get_rrec(&s->rlayer);
- sess = s->session;
- 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) < SSL3_RT_HEADER_LENGTH)) {
- n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
- SSL3_BUFFER_get_len(&s->rlayer.rbuf), 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);
- /*
- * Check whether this is a regular record or an SSLv2 style record. The
- * latter is only used in an initial ClientHello for old clients. We
- * check s->read_hash and s->enc_read_ctx to ensure this does not apply
- * during renegotiation
- */
- if (s->first_packet && s->server && !s->read_hash && !s->enc_read_ctx
- && (p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) {
- /* SSLv2 style record */
- rr->type = SSL3_RT_HANDSHAKE;
- rr->rec_version = SSL2_VERSION;
- rr->length = ((p[0] & 0x7f) << 8) | p[1];
- if (rr->length > SSL3_BUFFER_get_len(&s->rlayer.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->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->type = *(p++);
- ssl_major = *(p++);
- ssl_minor = *(p++);
- version = (ssl_major << 8) | ssl_minor;
- rr->rec_version = version;
- n2s(p, rr->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) {
- SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
- goto err;
- }
- if (rr->length >
- SSL3_BUFFER_get_len(&s->rlayer.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->rec_version == SSL2_VERSION) {
- i = rr->length + SSL2_RT_HEADER_LENGTH - SSL3_RT_HEADER_LENGTH;
- } else {
- i = rr->length;
- }
- if (i > 0) {
- /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
- n = ssl3_read_n(s, i, i, 1);
- 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->rec_version == SSL2_VERSION) {
- rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
- } else {
- rr->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->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->data = rr->input;
- rr->orig_len = rr->length;
- /*
- * 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);
- if (rr->length < mac_size) {
- al = SSL_AD_DECODE_ERROR;
- SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
- goto f_err;
- }
- rr->length -= mac_size;
- mac = rr->data + rr->length;
- i = s->method->ssl3_enc->mac(s, 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, 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 TLS_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);
- /*
- * 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_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, 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, 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;
- }
- /* 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_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
- goto f_err;
- }
- if (!ssl3_do_uncompress(s)) {
- al = SSL_AD_DECOMPRESSION_FAILURE;
- SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
- goto f_err;
- }
- }
- if (rr->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->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);
- /* just read a 0 length packet */
- if (rr->length == 0) {
- empty_record_count++;
- if (empty_record_count > MAX_EMPTY_RECORDS) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
- goto f_err;
- }
- goto again;
- }
- return (1);
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
- return (ret);
- }
- int ssl3_do_uncompress(SSL *ssl)
- {
- #ifndef OPENSSL_NO_COMP
- int i;
- SSL3_RECORD *rr;
- rr = RECORD_LAYER_get_rrec(&ssl->rlayer);
- 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)
- {
- #ifndef OPENSSL_NO_COMP
- int i;
- SSL3_RECORD *wr;
- wr = RECORD_LAYER_get_wrec(&ssl->rlayer);
- 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 the record in |s->wrec| / |s->rrec|, respectively.
- *
- * 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, int send)
- {
- SSL3_RECORD *rec;
- EVP_CIPHER_CTX *ds;
- unsigned long l;
- int bs, i, mac_size = 0;
- const EVP_CIPHER *enc;
- if (send) {
- ds = s->enc_write_ctx;
- rec = RECORD_LAYER_get_wrec(&s->rlayer);
- if (s->enc_write_ctx == NULL)
- enc = NULL;
- else
- enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
- } else {
- ds = s->enc_read_ctx;
- rec = RECORD_LAYER_get_rrec(&s->rlayer);
- 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(s, rec, bs, mac_size);
- }
- return (1);
- }
- /*-
- * tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
- *
- * 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, int send)
- {
- SSL3_RECORD *rec;
- EVP_CIPHER_CTX *ds;
- unsigned long l;
- int bs, i, j, k, pad = 0, ret, mac_size = 0;
- const EVP_CIPHER *enc;
- 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;
- rec = RECORD_LAYER_get_wrec(&s->rlayer);
- 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) {
- if (rec->data != rec->input)
- /*
- * we can't write into the input stream: Can this ever
- * happen?? (steve)
- */
- fprintf(stderr,
- "%s:%d: rec->data != rec->input\n",
- __FILE__, __LINE__);
- else if (RAND_bytes(rec->input, ivlen) <= 0)
- 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;
- rec = RECORD_LAYER_get_rrec(&s->rlayer);
- 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;
- ret = 1;
- } else {
- l = rec->length;
- bs = EVP_CIPHER_CTX_block_size(ds);
- if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds)) & EVP_CIPH_FLAG_AEAD_CIPHER) {
- unsigned char buf[EVP_AEAD_TLS1_AAD_LEN], *seq;
- seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
- : RECORD_LAYER_get_read_sequence(&s->rlayer);
- if (SSL_IS_DTLS(s)) {
- 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, dtlsseq, 8);
- } else {
- memcpy(buf, seq, 8);
- for (i = 7; i >= 0; i--) { /* increment */
- ++seq[i];
- if (seq[i] != 0)
- break;
- }
- }
- buf[8] = rec->type;
- buf[9] = (unsigned char)(s->version >> 8);
- buf[10] = (unsigned char)(s->version);
- buf[11] = rec->length >> 8;
- buf[12] = rec->length & 0xff;
- pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
- EVP_AEAD_TLS1_AAD_LEN, buf);
- if (pad <= 0)
- return -1;
- if (send) {
- l += pad;
- rec->length += pad;
- }
- } else if ((bs != 1) && send) {
- i = bs - ((int)l % bs);
- /* Add weird padding of upto 256 bytes */
- /* we need to add 'i' padding bytes of value j */
- j = i - 1;
- for (k = (int)l; k < (int)(l + i); k++)
- rec->input[k] = j;
- l += i;
- rec->length += i;
- }
- if (!send) {
- if (l == 0 || l % bs != 0)
- return 0;
- }
- i = EVP_Cipher(ds, rec->data, rec->input, l);
- 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) {
- rec->data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
- rec->input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
- rec->length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
- } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
- rec->data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
- rec->input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
- rec->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)
- ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
- if (pad && !send)
- rec->length -= pad;
- }
- return ret;
- }
- int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
- {
- SSL3_RECORD *rec;
- 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) {
- rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
- mac_sec = &(ssl->s3->write_mac_secret[0]);
- seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
- hash = ssl->write_hash;
- } else {
- rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
- 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, unsigned char *md, int send)
- {
- SSL3_RECORD *rec;
- 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) {
- rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
- seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
- hash = ssl->write_hash;
- } else {
- rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
- 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())
- tls_fips_digest_extra(ssl->enc_read_ctx,
- mac_ctx, rec->input,
- rec->length, rec->orig_len);
- }
- EVP_MD_CTX_free(hmac);
- #ifdef TLS_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 TLS_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.
- *
- * 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(const SSL *s,
- 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.
- *
- * 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 = 255; /* maximum amount of padding. */
- if (to_check > rec->length - 1)
- to_check = rec->length - 1;
- 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).
- *
- * 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
- void ssl3_cbc_copy_mac(unsigned char *out,
- const SSL3_RECORD *rec, unsigned 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.
- */
- 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 dtls1_process_record(SSL *s)
- {
- 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, 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 TLS_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, 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)) {
- 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);
- }
- /*
- * 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)
- {
- 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);
- /* 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);
- /* 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);
- }
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