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openssl/ssl/s3_both.c
Dr. Stephen Henson bb1a486603 Make message buffer slightly larger than message. 
Grow TLS/DTLS 16 bytes more than strictly necessary as a precaution against
OOB reads. In most cases this will have no effect because the message buffer
will be large enough already.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 006a788c84)
2016-09-21 20:01:32 +01:00

826 lines
27 KiB
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/* ssl/s3_both.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) 1998-2002 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).
*
*/
/* ====================================================================
* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
* ECC cipher suite support in OpenSSL originally developed by
* SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
*/
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include "ssl_locl.h"
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
/*
* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
* SSL3_RT_CHANGE_CIPHER_SPEC)
*/
int ssl3_do_write(SSL *s, int type)
{
int ret;
ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
s->init_num);
if (ret < 0)
return (-1);
if (type == SSL3_RT_HANDSHAKE)
/*
* should not be done for 'Hello Request's, but in that case we'll
* ignore the result anyway
*/
ssl3_finish_mac(s, (unsigned char *)&s->init_buf->data[s->init_off],
ret);
if (ret == s->init_num) {
if (s->msg_callback)
s->msg_callback(1, s->version, type, s->init_buf->data,
(size_t)(s->init_off + s->init_num), s,
s->msg_callback_arg);
return (1);
}
s->init_off += ret;
s->init_num -= ret;
return (0);
}
int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen)
{
unsigned char *p, *d;
int i;
unsigned long l;
if (s->state == a) {
d = (unsigned char *)s->init_buf->data;
p = &(d[4]);
i = s->method->ssl3_enc->final_finish_mac(s,
sender, slen,
s->s3->tmp.finish_md);
if (i <= 0)
return 0;
s->s3->tmp.finish_md_len = i;
memcpy(p, s->s3->tmp.finish_md, i);
p += i;
l = i;
/*
* Copy the finished so we can use it for renegotiation checks
*/
if (s->type == SSL_ST_CONNECT) {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
s->s3->previous_client_finished_len = i;
} else {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
s->s3->previous_server_finished_len = i;
}
#ifdef OPENSSL_SYS_WIN16
/*
* MSVC 1.5 does not clear the top bytes of the word unless I do
* this.
*/
l &= 0xffff;
#endif
*(d++) = SSL3_MT_FINISHED;
l2n3(l, d);
s->init_num = (int)l + 4;
s->init_off = 0;
s->state = b;
}
/* SSL3_ST_SEND_xxxxxx_HELLO_B */
return (ssl3_do_write(s, SSL3_RT_HANDSHAKE));
}
#ifndef OPENSSL_NO_NEXTPROTONEG
/*
* ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
* to far.
*/
static void ssl3_take_mac(SSL *s)
{
const char *sender;
int slen;
/*
* If no new cipher setup return immediately: other functions will set
* the appropriate error.
*/
if (s->s3->tmp.new_cipher == NULL)
return;
if (s->state & SSL_ST_CONNECT) {
sender = s->method->ssl3_enc->server_finished_label;
slen = s->method->ssl3_enc->server_finished_label_len;
} else {
sender = s->method->ssl3_enc->client_finished_label;
slen = s->method->ssl3_enc->client_finished_label_len;
}
s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
sender,
slen,
s->s3->tmp.peer_finish_md);
}
#endif
int ssl3_get_finished(SSL *s, int a, int b)
{
int al, i, ok;
long n;
unsigned char *p;
#ifdef OPENSSL_NO_NEXTPROTONEG
/*
* the mac has already been generated when we received the change cipher
* spec message and is in s->s3->tmp.peer_finish_md.
*/
#endif
/* 64 argument should actually be 36+4 :-) */
n = s->method->ssl_get_message(s, a, b, SSL3_MT_FINISHED, 64, &ok);
if (!ok)
return ((int)n);
/* If this occurs, we have missed a message */
if (!s->s3->change_cipher_spec) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
goto f_err;
}
s->s3->change_cipher_spec = 0;
p = (unsigned char *)s->init_msg;
i = s->s3->tmp.peer_finish_md_len;
if (i != n) {
al = SSL_AD_DECODE_ERROR;
SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
goto f_err;
}
if (CRYPTO_memcmp(p, s->s3->tmp.peer_finish_md, i) != 0) {
al = SSL_AD_DECRYPT_ERROR;
SSLerr(SSL_F_SSL3_GET_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
goto f_err;
}
/*
* Copy the finished so we can use it for renegotiation checks
*/
if (s->type == SSL_ST_ACCEPT) {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
s->s3->previous_client_finished_len = i;
} else {
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
s->s3->previous_server_finished_len = i;
}
return (1);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return (0);
}
/*-
* for these 2 messages, we need to
* ssl->enc_read_ctx re-init
* ssl->s3->read_sequence zero
* ssl->s3->read_mac_secret re-init
* ssl->session->read_sym_enc assign
* ssl->session->read_compression assign
* ssl->session->read_hash assign
*/
int ssl3_send_change_cipher_spec(SSL *s, int a, int b)
{
unsigned char *p;
if (s->state == a) {
p = (unsigned char *)s->init_buf->data;
*p = SSL3_MT_CCS;
s->init_num = 1;
s->init_off = 0;
s->state = b;
}
/* SSL3_ST_CW_CHANGE_B */
return (ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
}
static int ssl3_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
{
int n;
unsigned char *p;
n = i2d_X509(x, NULL);
if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) {
SSLerr(SSL_F_SSL3_ADD_CERT_TO_BUF, ERR_R_BUF_LIB);
return (-1);
}
p = (unsigned char *)&(buf->data[*l]);
l2n3(n, p);
i2d_X509(x, &p);
*l += n + 3;
return (0);
}
unsigned long ssl3_output_cert_chain(SSL *s, X509 *x)
{
unsigned char *p;
int i;
unsigned long l = 7;
BUF_MEM *buf;
int no_chain;
if ((s->mode & SSL_MODE_NO_AUTO_CHAIN) || s->ctx->extra_certs)
no_chain = 1;
else
no_chain = 0;
/* TLSv1 sends a chain with nothing in it, instead of an alert */
buf = s->init_buf;
if (!BUF_MEM_grow_clean(buf, 10)) {
SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB);
return (0);
}
if (x != NULL) {
if (no_chain) {
if (ssl3_add_cert_to_buf(buf, &l, x))
return (0);
} else {
X509_STORE_CTX xs_ctx;
if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) {
SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB);
return (0);
}
X509_verify_cert(&xs_ctx);
/* Don't leave errors in the queue */
ERR_clear_error();
for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) {
x = sk_X509_value(xs_ctx.chain, i);
if (ssl3_add_cert_to_buf(buf, &l, x)) {
X509_STORE_CTX_cleanup(&xs_ctx);
return 0;
}
}
X509_STORE_CTX_cleanup(&xs_ctx);
}
}
/* Thawte special :-) */
for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) {
x = sk_X509_value(s->ctx->extra_certs, i);
if (ssl3_add_cert_to_buf(buf, &l, x))
return (0);
}
l -= 7;
p = (unsigned char *)&(buf->data[4]);
l2n3(l, p);
l += 3;
p = (unsigned char *)&(buf->data[0]);
*(p++) = SSL3_MT_CERTIFICATE;
l2n3(l, p);
l += 4;
return (l);
}
/*
* Obtain handshake message of message type 'mt' (any if mt == -1), maximum
* acceptable body length 'max'. The first four bytes (msg_type and length)
* are read in state 'st1', the body is read in state 'stn'.
*/
long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
unsigned char *p;
unsigned long l;
long n;
int i, al;
if (s->s3->tmp.reuse_message) {
s->s3->tmp.reuse_message = 0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok = 1;
s->state = stn;
s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
p = (unsigned char *)s->init_buf->data;
if (s->state == st1) { /* s->init_num < SSL3_HM_HEADER_LENGTH */
int skip_message;
do {
while (s->init_num < SSL3_HM_HEADER_LENGTH) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
&p[s->init_num],
SSL3_HM_HEADER_LENGTH -
s->init_num, 0);
if (i <= 0) {
s->rwstate = SSL_READING;
*ok = 0;
return i;
}
s->init_num += i;
}
skip_message = 0;
if (!s->server)
if (p[0] == SSL3_MT_HELLO_REQUEST)
/*
* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them if
* their format is correct. Does not count for 'Finished'
* MAC.
*/
if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
s->init_num = 0;
skip_message = 1;
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, SSL3_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
}
}
while (skip_message);
/* s->init_num == SSL3_HM_HEADER_LENGTH */
if ((mt >= 0) && (*p != mt)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
if ((mt < 0) && (*p == SSL3_MT_CLIENT_HELLO) &&
(st1 == SSL3_ST_SR_CERT_A) && (stn == SSL3_ST_SR_CERT_B)) {
/*
* At this point we have got an MS SGC second client hello (maybe
* we should always allow the client to start a new handshake?).
* We need to restart the mac. Don't increment
* {num,total}_renegotiations because we have not completed the
* handshake.
*/
ssl3_init_finished_mac(s);
}
s->s3->tmp.message_type = *(p++);
n2l3(p, l);
if (l > (unsigned long)max) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
goto f_err;
}
/*
* Make buffer slightly larger than message length as a precaution
* against small OOB reads e.g. CVE-2016-6306
*/
if (l
&& !BUF_MEM_grow_clean(s->init_buf,
(int)l + SSL3_HM_HEADER_LENGTH + 16)) {
SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
goto err;
}
s->s3->tmp.message_size = l;
s->state = stn;
s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
s->init_num = 0;
}
/* next state (stn) */
p = s->init_msg;
n = s->s3->tmp.message_size - s->init_num;
while (n > 0) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &p[s->init_num],
n, 0);
if (i <= 0) {
s->rwstate = SSL_READING;
*ok = 0;
return i;
}
s->init_num += i;
n -= i;
}
#ifndef OPENSSL_NO_NEXTPROTONEG
/*
* If receiving Finished, record MAC of prior handshake messages for
* Finished verification.
*/
if (*s->init_buf->data == SSL3_MT_FINISHED)
ssl3_take_mac(s);
#endif
/* Feed this message into MAC computation. */
ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
s->init_num + SSL3_HM_HEADER_LENGTH);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
(size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
*ok = 1;
return s->init_num;
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
*ok = 0;
return (-1);
}
int ssl_cert_type(X509 *x, EVP_PKEY *pkey)
{
EVP_PKEY *pk;
int ret = -1, i;
if (pkey == NULL)
pk = X509_get_pubkey(x);
else
pk = pkey;
if (pk == NULL)
goto err;
i = pk->type;
if (i == EVP_PKEY_RSA) {
ret = SSL_PKEY_RSA_ENC;
} else if (i == EVP_PKEY_DSA) {
ret = SSL_PKEY_DSA_SIGN;
}
#ifndef OPENSSL_NO_EC
else if (i == EVP_PKEY_EC) {
ret = SSL_PKEY_ECC;
}
#endif
else if (i == NID_id_GostR3410_94 || i == NID_id_GostR3410_94_cc) {
ret = SSL_PKEY_GOST94;
} else if (i == NID_id_GostR3410_2001 || i == NID_id_GostR3410_2001_cc) {
ret = SSL_PKEY_GOST01;
}
err:
if (!pkey)
EVP_PKEY_free(pk);
return (ret);
}
int ssl_verify_alarm_type(long type)
{
int al;
switch (type) {
case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
case X509_V_ERR_UNABLE_TO_GET_CRL:
case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
al = SSL_AD_UNKNOWN_CA;
break;
case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
case X509_V_ERR_CERT_NOT_YET_VALID:
case X509_V_ERR_CRL_NOT_YET_VALID:
case X509_V_ERR_CERT_UNTRUSTED:
case X509_V_ERR_CERT_REJECTED:
al = SSL_AD_BAD_CERTIFICATE;
break;
case X509_V_ERR_CERT_SIGNATURE_FAILURE:
case X509_V_ERR_CRL_SIGNATURE_FAILURE:
al = SSL_AD_DECRYPT_ERROR;
break;
case X509_V_ERR_CERT_HAS_EXPIRED:
case X509_V_ERR_CRL_HAS_EXPIRED:
al = SSL_AD_CERTIFICATE_EXPIRED;
break;
case X509_V_ERR_CERT_REVOKED:
al = SSL_AD_CERTIFICATE_REVOKED;
break;
case X509_V_ERR_UNSPECIFIED:
case X509_V_ERR_OUT_OF_MEM:
case X509_V_ERR_INVALID_CALL:
case X509_V_ERR_STORE_LOOKUP:
al = SSL_AD_INTERNAL_ERROR;
break;
case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
case X509_V_ERR_CERT_CHAIN_TOO_LONG:
case X509_V_ERR_PATH_LENGTH_EXCEEDED:
case X509_V_ERR_INVALID_CA:
al = SSL_AD_UNKNOWN_CA;
break;
case X509_V_ERR_APPLICATION_VERIFICATION:
al = SSL_AD_HANDSHAKE_FAILURE;
break;
case X509_V_ERR_INVALID_PURPOSE:
al = SSL_AD_UNSUPPORTED_CERTIFICATE;
break;
default:
al = SSL_AD_CERTIFICATE_UNKNOWN;
break;
}
return (al);
}
#ifndef OPENSSL_NO_BUF_FREELISTS
/*-
* On some platforms, malloc() performance is bad enough that you can't just
* free() and malloc() buffers all the time, so we need to use freelists from
* unused buffers. Currently, each freelist holds memory chunks of only a
* given size (list->chunklen); other sized chunks are freed and malloced.
* This doesn't help much if you're using many different SSL option settings
* with a given context. (The options affecting buffer size are
* max_send_fragment, read buffer vs write buffer,
* SSL_OP_MICROSOFT_BIG_WRITE_BUFFER, SSL_OP_NO_COMPRESSION, and
* SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS.) Using a separate freelist for every
* possible size is not an option, since max_send_fragment can take on many
* different values.
*
* If you are on a platform with a slow malloc(), and you're using SSL
* connections with many different settings for these options, and you need to
* use the SSL_MOD_RELEASE_BUFFERS feature, you have a few options:
* - Link against a faster malloc implementation.
* - Use a separate SSL_CTX for each option set.
* - Improve this code.
*/
static void *freelist_extract(SSL_CTX *ctx, int for_read, int sz)
{
SSL3_BUF_FREELIST *list;
SSL3_BUF_FREELIST_ENTRY *ent = NULL;
void *result = NULL;
CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
list = for_read ? ctx->rbuf_freelist : ctx->wbuf_freelist;
if (list != NULL && sz == (int)list->chunklen)
ent = list->head;
if (ent != NULL) {
list->head = ent->next;
result = ent;
if (--list->len == 0)
list->chunklen = 0;
}
CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
if (!result)
result = OPENSSL_malloc(sz);
return result;
}
static void freelist_insert(SSL_CTX *ctx, int for_read, size_t sz, void *mem)
{
SSL3_BUF_FREELIST *list;
SSL3_BUF_FREELIST_ENTRY *ent;
CRYPTO_w_lock(CRYPTO_LOCK_SSL_CTX);
list = for_read ? ctx->rbuf_freelist : ctx->wbuf_freelist;
if (list != NULL &&
(sz == list->chunklen || list->chunklen == 0) &&
list->len < ctx->freelist_max_len && sz >= sizeof(*ent)) {
list->chunklen = sz;
ent = mem;
ent->next = list->head;
list->head = ent;
++list->len;
mem = NULL;
}
CRYPTO_w_unlock(CRYPTO_LOCK_SSL_CTX);
if (mem)
OPENSSL_free(mem);
}
#else
# define freelist_extract(c,fr,sz) OPENSSL_malloc(sz)
# define freelist_insert(c,fr,sz,m) OPENSSL_free(m)
#endif
int ssl3_setup_read_buffer(SSL *s)
{
unsigned char *p;
size_t len, align = 0, headerlen;
if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
headerlen = DTLS1_RT_HEADER_LENGTH;
else
headerlen = SSL3_RT_HEADER_LENGTH;
#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
#endif
if (s->s3->rbuf.buf == NULL) {
len = SSL3_RT_MAX_PLAIN_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) {
s->s3->init_extra = 1;
len += SSL3_RT_MAX_EXTRA;
}
#ifndef OPENSSL_NO_COMP
if (!(s->options & SSL_OP_NO_COMPRESSION))
len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
#endif
if ((p = freelist_extract(s->ctx, 1, len)) == NULL)
goto err;
s->s3->rbuf.buf = p;
s->s3->rbuf.len = len;
}
s->packet = &(s->s3->rbuf.buf[0]);
return 1;
err:
SSLerr(SSL_F_SSL3_SETUP_READ_BUFFER, ERR_R_MALLOC_FAILURE);
return 0;
}
int ssl3_setup_write_buffer(SSL *s)
{
unsigned char *p;
size_t len, align = 0, headerlen;
if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
headerlen = DTLS1_RT_HEADER_LENGTH + 1;
else
headerlen = SSL3_RT_HEADER_LENGTH;
#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
align = (-SSL3_RT_HEADER_LENGTH) & (SSL3_ALIGN_PAYLOAD - 1);
#endif
if (s->s3->wbuf.buf == NULL) {
len = s->max_send_fragment
+ SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD + headerlen + align;
#ifndef OPENSSL_NO_COMP
if (!(s->options & SSL_OP_NO_COMPRESSION))
len += SSL3_RT_MAX_COMPRESSED_OVERHEAD;
#endif
if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS))
len += headerlen + align + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
if ((p = freelist_extract(s->ctx, 0, len)) == NULL)
goto err;
s->s3->wbuf.buf = p;
s->s3->wbuf.len = len;
}
return 1;
err:
SSLerr(SSL_F_SSL3_SETUP_WRITE_BUFFER, ERR_R_MALLOC_FAILURE);
return 0;
}
int ssl3_setup_buffers(SSL *s)
{
if (!ssl3_setup_read_buffer(s))
return 0;
if (!ssl3_setup_write_buffer(s))
return 0;
return 1;
}
int ssl3_release_write_buffer(SSL *s)
{
if (s->s3->wbuf.buf != NULL) {
freelist_insert(s->ctx, 0, s->s3->wbuf.len, s->s3->wbuf.buf);
s->s3->wbuf.buf = NULL;
}
return 1;
}
int ssl3_release_read_buffer(SSL *s)
{
if (s->s3->rbuf.buf != NULL) {
freelist_insert(s->ctx, 1, s->s3->rbuf.len, s->s3->rbuf.buf);
s->s3->rbuf.buf = NULL;
}
return 1;
}
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