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openssl/ssl/s23_srvr.c
Bodo Moeller 6bfe55380a Support TLS_FALLBACK_SCSV. 
Reviewed-by: Rich Salz <rsalz@openssl.org>
2014-10-15 04:05:42 +02:00

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/* ssl/s23_srvr.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) 1998-2006 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 <stdio.h>
#include "ssl_locl.h"
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#ifdef OPENSSL_FIPS
#include <openssl/fips.h>
#endif
static const SSL_METHOD *ssl23_get_server_method(int ver);
int ssl23_get_client_hello(SSL *s);
static const SSL_METHOD *ssl23_get_server_method(int ver)
{
#ifndef OPENSSL_NO_SSL2
if (ver == SSL2_VERSION)
return(SSLv2_server_method());
#endif
if (ver == SSL3_VERSION)
return(SSLv3_server_method());
else if (ver == TLS1_VERSION)
return(TLSv1_server_method());
else if (ver == TLS1_1_VERSION)
return(TLSv1_1_server_method());
else if (ver == TLS1_2_VERSION)
return(TLSv1_2_server_method());
else
return(NULL);
}
IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
ssl23_accept,
ssl_undefined_function,
ssl23_get_server_method)
int ssl23_accept(SSL *s)
{
BUF_MEM *buf;
unsigned long Time=(unsigned long)time(NULL);
void (*cb)(const SSL *ssl,int type,int val)=NULL;
int ret= -1;
int new_state,state;
RAND_add(&Time,sizeof(Time),0);
ERR_clear_error();
clear_sys_error();
if (s->info_callback != NULL)
cb=s->info_callback;
else if (s->ctx->info_callback != NULL)
cb=s->ctx->info_callback;
s->in_handshake++;
if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
for (;;)
{
state=s->state;
switch(s->state)
{
case SSL_ST_BEFORE:
case SSL_ST_ACCEPT:
case SSL_ST_BEFORE|SSL_ST_ACCEPT:
case SSL_ST_OK|SSL_ST_ACCEPT:
s->server=1;
if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
/* s->version=SSL3_VERSION; */
s->type=SSL_ST_ACCEPT;
if (s->init_buf == NULL)
{
if ((buf=BUF_MEM_new()) == NULL)
{
ret= -1;
goto end;
}
if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
{
ret= -1;
goto end;
}
s->init_buf=buf;
}
ssl3_init_finished_mac(s);
s->state=SSL23_ST_SR_CLNT_HELLO_A;
s->ctx->stats.sess_accept++;
s->init_num=0;
break;
case SSL23_ST_SR_CLNT_HELLO_A:
case SSL23_ST_SR_CLNT_HELLO_B:
s->shutdown=0;
ret=ssl23_get_client_hello(s);
if (ret >= 0) cb=NULL;
goto end;
/* break; */
default:
SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
ret= -1;
goto end;
/* break; */
}
if ((cb != NULL) && (s->state != state))
{
new_state=s->state;
s->state=state;
cb(s,SSL_CB_ACCEPT_LOOP,1);
s->state=new_state;
}
}
end:
s->in_handshake--;
if (cb != NULL)
cb(s,SSL_CB_ACCEPT_EXIT,ret);
return(ret);
}
int ssl23_get_client_hello(SSL *s)
{
char buf_space[11]; /* Request this many bytes in initial read.
* We can detect SSL 3.0/TLS 1.0 Client Hellos
* ('type == 3') correctly only when the following
* is in a single record, which is not guaranteed by
* the protocol specification:
* Byte Content
* 0 type \
* 1/2 version > record header
* 3/4 length /
* 5 msg_type \
* 6-8 length > Client Hello message
* 9/10 client_version /
*/
char *buf= &(buf_space[0]);
unsigned char *p,*d,*d_len,*dd;
unsigned int i;
unsigned int csl,sil,cl;
int n=0,j;
int type=0;
int v[2];
if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
{
/* read the initial header */
v[0]=v[1]=0;
if (!ssl3_setup_buffers(s)) goto err;
n=ssl23_read_bytes(s, sizeof buf_space);
if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
p=s->packet;
memcpy(buf,p,n);
if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
{
/*
* SSLv2 header
*/
if ((p[3] == 0x00) && (p[4] == 0x02))
{
v[0]=p[3]; v[1]=p[4];
/* SSLv2 */
if (!(s->options & SSL_OP_NO_SSLv2))
type=1;
}
else if (p[3] == SSL3_VERSION_MAJOR)
{
v[0]=p[3]; v[1]=p[4];
/* SSLv3/TLSv1 */
if (p[4] >= TLS1_VERSION_MINOR)
{
if (p[4] >= TLS1_2_VERSION_MINOR &&
!(s->options & SSL_OP_NO_TLSv1_2))
{
s->version=TLS1_2_VERSION;
s->state=SSL23_ST_SR_CLNT_HELLO_B;
}
else if (p[4] >= TLS1_1_VERSION_MINOR &&
!(s->options & SSL_OP_NO_TLSv1_1))
{
s->version=TLS1_1_VERSION;
/* type=2; */ /* done later to survive restarts */
s->state=SSL23_ST_SR_CLNT_HELLO_B;
}
else if (!(s->options & SSL_OP_NO_TLSv1))
{
s->version=TLS1_VERSION;
/* type=2; */ /* done later to survive restarts */
s->state=SSL23_ST_SR_CLNT_HELLO_B;
}
else if (!(s->options & SSL_OP_NO_SSLv3))
{
s->version=SSL3_VERSION;
/* type=2; */
s->state=SSL23_ST_SR_CLNT_HELLO_B;
}
else if (!(s->options & SSL_OP_NO_SSLv2))
{
type=1;
}
}
else if (!(s->options & SSL_OP_NO_SSLv3))
{
s->version=SSL3_VERSION;
/* type=2; */
s->state=SSL23_ST_SR_CLNT_HELLO_B;
}
else if (!(s->options & SSL_OP_NO_SSLv2))
type=1;
}
}
else if ((p[0] == SSL3_RT_HANDSHAKE) &&
(p[1] == SSL3_VERSION_MAJOR) &&
(p[5] == SSL3_MT_CLIENT_HELLO) &&
((p[3] == 0 && p[4] < 5 /* silly record length? */)
|| (p[9] >= p[1])))
{
/*
* SSLv3 or tls1 header
*/
v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
/* We must look at client_version inside the Client Hello message
* to get the correct minor version.
* However if we have only a pathologically small fragment of the
* Client Hello message, this would be difficult, and we'd have
* to read more records to find out.
* No known SSL 3.0 client fragments ClientHello like this,
* so we simply reject such connections to avoid
* protocol version downgrade attacks. */
if (p[3] == 0 && p[4] < 6)
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
goto err;
}
/* if major version number > 3 set minor to a value
* which will use the highest version 3 we support.
* If TLS 2.0 ever appears we will need to revise
* this....
*/
if (p[9] > SSL3_VERSION_MAJOR)
v[1]=0xff;
else
v[1]=p[10]; /* minor version according to client_version */
if (v[1] >= TLS1_VERSION_MINOR)
{
if (v[1] >= TLS1_2_VERSION_MINOR &&
!(s->options & SSL_OP_NO_TLSv1_2))
{
s->version=TLS1_2_VERSION;
type=3;
}
else if (v[1] >= TLS1_1_VERSION_MINOR &&
!(s->options & SSL_OP_NO_TLSv1_1))
{
s->version=TLS1_1_VERSION;
type=3;
}
else if (!(s->options & SSL_OP_NO_TLSv1))
{
s->version=TLS1_VERSION;
type=3;
}
else if (!(s->options & SSL_OP_NO_SSLv3))
{
s->version=SSL3_VERSION;
type=3;
}
}
else
{
/* client requests SSL 3.0 */
if (!(s->options & SSL_OP_NO_SSLv3))
{
s->version=SSL3_VERSION;
type=3;
}
else if (!(s->options & SSL_OP_NO_TLSv1))
{
/* we won't be able to use TLS of course,
* but this will send an appropriate alert */
s->version=TLS1_VERSION;
type=3;
}
}
}
else if ((strncmp("GET ", (char *)p,4) == 0) ||
(strncmp("POST ",(char *)p,5) == 0) ||
(strncmp("HEAD ",(char *)p,5) == 0) ||
(strncmp("PUT ", (char *)p,4) == 0))
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
goto err;
}
else if (strncmp("CONNECT",(char *)p,7) == 0)
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
goto err;
}
}
/* ensure that TLS_MAX_VERSION is up-to-date */
OPENSSL_assert(s->version <= TLS_MAX_VERSION);
#ifdef OPENSSL_FIPS
if (FIPS_mode() && (s->version < TLS1_VERSION))
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
goto err;
}
#endif
if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
{
/* we have SSLv3/TLSv1 in an SSLv2 header
* (other cases skip this state) */
type=2;
p=s->packet;
v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
v[1] = p[4];
/* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
* header is sent directly on the wire, not wrapped as a TLS
* record. It's format is:
* Byte Content
* 0-1 msg_length
* 2 msg_type
* 3-4 version
* 5-6 cipher_spec_length
* 7-8 session_id_length
* 9-10 challenge_length
* ... ...
*/
n=((p[0]&0x7f)<<8)|p[1];
if (n > (1024*4))
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
goto err;
}
if (n < 9)
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
goto err;
}
j=ssl23_read_bytes(s,n+2);
/* We previously read 11 bytes, so if j > 0, we must have
* j == n+2 == s->packet_length. We have at least 11 valid
* packet bytes. */
if (j <= 0) return(j);
ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
if (s->msg_callback)
s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
p=s->packet;
p+=5;
n2s(p,csl);
n2s(p,sil);
n2s(p,cl);
d=(unsigned char *)s->init_buf->data;
if ((csl+sil+cl+11) != s->packet_length) /* We can't have TLS extensions in SSL 2.0 format
* Client Hello, can we? Error condition should be
* '>' otherweise */
{
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
goto err;
}
/* record header: msg_type ... */
*(d++) = SSL3_MT_CLIENT_HELLO;
/* ... and length (actual value will be written later) */
d_len = d;
d += 3;
/* client_version */
*(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
*(d++) = v[1];
/* lets populate the random area */
/* get the challenge_length */
i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
memset(d,0,SSL3_RANDOM_SIZE);
memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
d+=SSL3_RANDOM_SIZE;
/* no session-id reuse */
*(d++)=0;
/* ciphers */
j=0;
dd=d;
d+=2;
for (i=0; i<csl; i+=3)
{
if (p[i] != 0) continue;
*(d++)=p[i+1];
*(d++)=p[i+2];
j+=2;
}
s2n(j,dd);
/* COMPRESSION */
*(d++)=1;
*(d++)=0;
#if 0
/* copy any remaining data with may be extensions */
p = p+csl+sil+cl;
while (p < s->packet+s->packet_length)
{
*(d++)=*(p++);
}
#endif
i = (d-(unsigned char *)s->init_buf->data) - 4;
l2n3((long)i, d_len);
/* get the data reused from the init_buf */
s->s3->tmp.reuse_message=1;
s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
s->s3->tmp.message_size=i;
}
/* imaginary new state (for program structure): */
/* s->state = SSL23_SR_CLNT_HELLO_C */
if (type == 1)
{
#ifdef OPENSSL_NO_SSL2
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
goto err;
#else
/* we are talking sslv2 */
/* we need to clean up the SSLv3/TLSv1 setup and put in the
* sslv2 stuff. */
if (s->s2 == NULL)
{
if (!ssl2_new(s))
goto err;
}
else
ssl2_clear(s);
if (s->s3 != NULL) ssl3_free(s);
if (!BUF_MEM_grow_clean(s->init_buf,
SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
{
goto err;
}
s->state=SSL2_ST_GET_CLIENT_HELLO_A;
if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)
s->s2->ssl2_rollback=0;
else
/* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
* (SSL 3.0 draft/RFC 2246, App. E.2) */
s->s2->ssl2_rollback=1;
/* setup the n bytes we have read so we get them from
* the sslv2 buffer */
s->rstate=SSL_ST_READ_HEADER;
s->packet_length=n;
s->packet= &(s->s2->rbuf[0]);
memcpy(s->packet,buf,n);
s->s2->rbuf_left=n;
s->s2->rbuf_offs=0;
s->method=SSLv2_server_method();
s->handshake_func=s->method->ssl_accept;
#endif
}
if ((type == 2) || (type == 3))
{
/* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
if (!ssl_init_wbio_buffer(s,1)) goto err;
/* we are in this state */
s->state=SSL3_ST_SR_CLNT_HELLO_A;
if (type == 3)
{
/* put the 'n' bytes we have read into the input buffer
* for SSLv3 */
s->rstate=SSL_ST_READ_HEADER;
s->packet_length=n;
if (s->s3->rbuf.buf == NULL)
if (!ssl3_setup_read_buffer(s))
goto err;
s->packet= &(s->s3->rbuf.buf[0]);
memcpy(s->packet,buf,n);
s->s3->rbuf.left=n;
s->s3->rbuf.offset=0;
}
else
{
s->packet_length=0;
s->s3->rbuf.left=0;
s->s3->rbuf.offset=0;
}
if (s->version == TLS1_2_VERSION)
s->method = TLSv1_2_server_method();
else if (s->version == TLS1_1_VERSION)
s->method = TLSv1_1_server_method();
else if (s->version == TLS1_VERSION)
s->method = TLSv1_server_method();
else
s->method = SSLv3_server_method();
#if 0 /* ssl3_get_client_hello does this */
s->client_version=(v[0]<<8)|v[1];
#endif
s->handshake_func=s->method->ssl_accept;
}
if ((type < 1) || (type > 3))
{
/* bad, very bad */
SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
goto err;
}
s->init_num=0;
if (buf != buf_space) OPENSSL_free(buf);
return(SSL_accept(s));
err:
if (buf != buf_space) OPENSSL_free(buf);
return(-1);
}
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