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openssl/ssl/t1_lib.c
Bodo Möller 40a706286f From HEAD: 
Fix double-free in TLS server name extensions which could lead to a remote
crash found by Codenomicon TLS test suite (CVE-2008-0891)

Reviewed by: openssl-security@openssl.org

Obtained from: jorton@redhat.com
2008-05-28 22:15:48 +00:00

1530 lines
44 KiB
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/* ssl/t1_lib.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) 1998-2007 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 <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/ocsp.h>
#include "ssl_locl.h"
const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
#ifndef OPENSSL_NO_TLSEXT
static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
const unsigned char *sess_id, int sesslen,
SSL_SESSION **psess);
#endif
SSL3_ENC_METHOD TLSv1_enc_data={
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
tls1_cert_verify_mac,
TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
};
long tls1_default_timeout(void)
{
/* 2 hours, the 24 hours mentioned in the TLSv1 spec
* is way too long for http, the cache would over fill */
return(60*60*2);
}
int tls1_new(SSL *s)
{
if (!ssl3_new(s)) return(0);
s->method->ssl_clear(s);
return(1);
}
void tls1_free(SSL *s)
{
ssl3_free(s);
}
void tls1_clear(SSL *s)
{
ssl3_clear(s);
s->version=TLS1_VERSION;
}
#ifndef OPENSSL_NO_EC
static int nid_list[] =
{
NID_sect163k1, /* sect163k1 (1) */
NID_sect163r1, /* sect163r1 (2) */
NID_sect163r2, /* sect163r2 (3) */
NID_sect193r1, /* sect193r1 (4) */
NID_sect193r2, /* sect193r2 (5) */
NID_sect233k1, /* sect233k1 (6) */
NID_sect233r1, /* sect233r1 (7) */
NID_sect239k1, /* sect239k1 (8) */
NID_sect283k1, /* sect283k1 (9) */
NID_sect283r1, /* sect283r1 (10) */
NID_sect409k1, /* sect409k1 (11) */
NID_sect409r1, /* sect409r1 (12) */
NID_sect571k1, /* sect571k1 (13) */
NID_sect571r1, /* sect571r1 (14) */
NID_secp160k1, /* secp160k1 (15) */
NID_secp160r1, /* secp160r1 (16) */
NID_secp160r2, /* secp160r2 (17) */
NID_secp192k1, /* secp192k1 (18) */
NID_X9_62_prime192v1, /* secp192r1 (19) */
NID_secp224k1, /* secp224k1 (20) */
NID_secp224r1, /* secp224r1 (21) */
NID_secp256k1, /* secp256k1 (22) */
NID_X9_62_prime256v1, /* secp256r1 (23) */
NID_secp384r1, /* secp384r1 (24) */
NID_secp521r1 /* secp521r1 (25) */
};
int tls1_ec_curve_id2nid(int curve_id)
{
/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
if ((curve_id < 1) || ((unsigned int)curve_id >
sizeof(nid_list)/sizeof(nid_list[0])))
return 0;
return nid_list[curve_id-1];
}
int tls1_ec_nid2curve_id(int nid)
{
/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
switch (nid)
{
case NID_sect163k1: /* sect163k1 (1) */
return 1;
case NID_sect163r1: /* sect163r1 (2) */
return 2;
case NID_sect163r2: /* sect163r2 (3) */
return 3;
case NID_sect193r1: /* sect193r1 (4) */
return 4;
case NID_sect193r2: /* sect193r2 (5) */
return 5;
case NID_sect233k1: /* sect233k1 (6) */
return 6;
case NID_sect233r1: /* sect233r1 (7) */
return 7;
case NID_sect239k1: /* sect239k1 (8) */
return 8;
case NID_sect283k1: /* sect283k1 (9) */
return 9;
case NID_sect283r1: /* sect283r1 (10) */
return 10;
case NID_sect409k1: /* sect409k1 (11) */
return 11;
case NID_sect409r1: /* sect409r1 (12) */
return 12;
case NID_sect571k1: /* sect571k1 (13) */
return 13;
case NID_sect571r1: /* sect571r1 (14) */
return 14;
case NID_secp160k1: /* secp160k1 (15) */
return 15;
case NID_secp160r1: /* secp160r1 (16) */
return 16;
case NID_secp160r2: /* secp160r2 (17) */
return 17;
case NID_secp192k1: /* secp192k1 (18) */
return 18;
case NID_X9_62_prime192v1: /* secp192r1 (19) */
return 19;
case NID_secp224k1: /* secp224k1 (20) */
return 20;
case NID_secp224r1: /* secp224r1 (21) */
return 21;
case NID_secp256k1: /* secp256k1 (22) */
return 22;
case NID_X9_62_prime256v1: /* secp256r1 (23) */
return 23;
case NID_secp384r1: /* secp384r1 (24) */
return 24;
case NID_secp521r1: /* secp521r1 (25) */
return 25;
default:
return 0;
}
}
#endif /* OPENSSL_NO_EC */
#ifndef OPENSSL_NO_TLSEXT
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
{
int extdatalen=0;
unsigned char *ret = p;
ret+=2;
if (ret>=limit) return NULL; /* this really never occurs, but ... */
if (s->tlsext_hostname != NULL)
{
/* Add TLS extension servername to the Client Hello message */
unsigned long size_str;
long lenmax;
/* check for enough space.
4 for the servername type and entension length
2 for servernamelist length
1 for the hostname type
2 for hostname length
+ hostname length
*/
if ((lenmax = limit - ret - 9) < 0
|| (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
return NULL;
/* extension type and length */
s2n(TLSEXT_TYPE_server_name,ret);
s2n(size_str+5,ret);
/* length of servername list */
s2n(size_str+3,ret);
/* hostname type, length and hostname */
*(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
s2n(size_str,ret);
memcpy(ret, s->tlsext_hostname, size_str);
ret+=size_str;
}
#ifndef OPENSSL_NO_EC
if (s->tlsext_ecpointformatlist != NULL)
{
/* Add TLS extension ECPointFormats to the ClientHello message */
long lenmax;
if ((lenmax = limit - ret - 5) < 0) return NULL;
if (s->tlsext_ecpointformatlist_length > (unsigned long)lenmax) return NULL;
if (s->tlsext_ecpointformatlist_length > 255)
{
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats,ret);
s2n(s->tlsext_ecpointformatlist_length + 1,ret);
*(ret++) = (unsigned char) s->tlsext_ecpointformatlist_length;
memcpy(ret, s->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist_length);
ret+=s->tlsext_ecpointformatlist_length;
}
if (s->tlsext_ellipticcurvelist != NULL)
{
/* Add TLS extension EllipticCurves to the ClientHello message */
long lenmax;
if ((lenmax = limit - ret - 6) < 0) return NULL;
if (s->tlsext_ellipticcurvelist_length > (unsigned long)lenmax) return NULL;
if (s->tlsext_ellipticcurvelist_length > 65532)
{
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_elliptic_curves,ret);
s2n(s->tlsext_ellipticcurvelist_length + 2, ret);
/* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
* elliptic_curve_list, but the examples use two bytes.
* http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
* resolves this to two bytes.
*/
s2n(s->tlsext_ellipticcurvelist_length, ret);
memcpy(ret, s->tlsext_ellipticcurvelist, s->tlsext_ellipticcurvelist_length);
ret+=s->tlsext_ellipticcurvelist_length;
}
#endif /* OPENSSL_NO_EC */
if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
{
int ticklen;
if (s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
else
ticklen = 0;
/* Check for enough room 2 for extension type, 2 for len
* rest for ticket
*/
if ((long)(limit - ret - 4 - ticklen) < 0) return NULL;
s2n(TLSEXT_TYPE_session_ticket,ret);
s2n(ticklen,ret);
if (ticklen)
{
memcpy(ret, s->session->tlsext_tick, ticklen);
ret += ticklen;
}
}
#ifdef TLSEXT_TYPE_opaque_prf_input
if (s->s3->client_opaque_prf_input != NULL)
{
size_t col = s->s3->client_opaque_prf_input_len;
if ((long)(limit - ret - 6 - col < 0))
return NULL;
if (col > 0xFFFD) /* can't happen */
return NULL;
s2n(TLSEXT_TYPE_opaque_prf_input, ret);
s2n(col + 2, ret);
s2n(col, ret);
memcpy(ret, s->s3->client_opaque_prf_input, col);
ret += col;
}
#endif
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
{
int i;
long extlen, idlen, itmp;
OCSP_RESPID *id;
idlen = 0;
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
{
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
itmp = i2d_OCSP_RESPID(id, NULL);
if (itmp <= 0)
return NULL;
idlen += itmp + 2;
}
if (s->tlsext_ocsp_exts)
{
extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
if (extlen < 0)
return NULL;
}
else
extlen = 0;
if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
if (extlen + idlen > 0xFFF0)
return NULL;
s2n(extlen + idlen + 5, ret);
*(ret++) = TLSEXT_STATUSTYPE_ocsp;
s2n(idlen, ret);
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
{
/* save position of id len */
unsigned char *q = ret;
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
/* skip over id len */
ret += 2;
itmp = i2d_OCSP_RESPID(id, &ret);
/* write id len */
s2n(itmp, q);
}
s2n(extlen, ret);
if (extlen > 0)
i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
}
if ((extdatalen = ret-p-2)== 0)
return p;
s2n(extdatalen,p);
return ret;
}
unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
{
int extdatalen=0;
unsigned char *ret = p;
ret+=2;
if (ret>=limit) return NULL; /* this really never occurs, but ... */
if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
{
if ((long)(limit - ret - 4) < 0) return NULL;
s2n(TLSEXT_TYPE_server_name,ret);
s2n(0,ret);
}
#ifndef OPENSSL_NO_EC
if (s->tlsext_ecpointformatlist != NULL)
{
/* Add TLS extension ECPointFormats to the ServerHello message */
long lenmax;
if ((lenmax = limit - ret - 5) < 0) return NULL;
if (s->tlsext_ecpointformatlist_length > (unsigned long)lenmax) return NULL;
if (s->tlsext_ecpointformatlist_length > 255)
{
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats,ret);
s2n(s->tlsext_ecpointformatlist_length + 1,ret);
*(ret++) = (unsigned char) s->tlsext_ecpointformatlist_length;
memcpy(ret, s->tlsext_ecpointformatlist, s->tlsext_ecpointformatlist_length);
ret+=s->tlsext_ecpointformatlist_length;
}
/* Currently the server should not respond with a SupportedCurves extension */
#endif /* OPENSSL_NO_EC */
if (s->tlsext_ticket_expected
&& !(SSL_get_options(s) & SSL_OP_NO_TICKET))
{
if ((long)(limit - ret - 4) < 0) return NULL;
s2n(TLSEXT_TYPE_session_ticket,ret);
s2n(0,ret);
}
if (s->tlsext_status_expected)
{
if ((long)(limit - ret - 4) < 0) return NULL;
s2n(TLSEXT_TYPE_status_request,ret);
s2n(0,ret);
}
#ifdef TLSEXT_TYPE_opaque_prf_input
if (s->s3->server_opaque_prf_input != NULL)
{
size_t sol = s->s3->server_opaque_prf_input_len;
if ((long)(limit - ret - 6 - sol) < 0)
return NULL;
if (sol > 0xFFFD) /* can't happen */
return NULL;
s2n(TLSEXT_TYPE_opaque_prf_input, ret);
s2n(sol + 2, ret);
s2n(sol, ret);
memcpy(ret, s->s3->server_opaque_prf_input, sol);
ret += sol;
}
#endif
if (((s->s3->tmp.new_cipher->id & 0xFFFF)==0x80 || (s->s3->tmp.new_cipher->id & 0xFFFF)==0x81)
&& (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG))
{ const unsigned char cryptopro_ext[36] = {
0xfd, 0xe8, /*65000*/
0x00, 0x20, /*32 bytes length*/
0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17};
if (limit-ret<36) return NULL;
memcpy(ret,cryptopro_ext,36);
ret+=36;
}
if ((extdatalen = ret-p-2)== 0)
return p;
s2n(extdatalen,p);
return ret;
}
int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
{
unsigned short type;
unsigned short size;
unsigned short len;
unsigned char *data = *p;
s->servername_done = 0;
s->tlsext_status_type = -1;
if (data >= (d+n-2))
return 1;
n2s(data,len);
if (data > (d+n-len))
return 1;
while (data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
return 1;
#if 0
fprintf(stderr,"Received extension type %d size %d\n",type,size);
#endif
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 0, type, data, size,
s->tlsext_debug_arg);
/* The servername extension is treated as follows:
- Only the hostname type is supported with a maximum length of 255.
- The servername is rejected if too long or if it contains zeros,
in which case an fatal alert is generated.
- The servername field is maintained together with the session cache.
- When a session is resumed, the servername call back invoked in order
to allow the application to position itself to the right context.
- The servername is acknowledged if it is new for a session or when
it is identical to a previously used for the same session.
Applications can control the behaviour. They can at any time
set a 'desirable' servername for a new SSL object. This can be the
case for example with HTTPS when a Host: header field is received and
a renegotiation is requested. In this case, a possible servername
presented in the new client hello is only acknowledged if it matches
the value of the Host: field.
- Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
if they provide for changing an explicit servername context for the session,
i.e. when the session has been established with a servername extension.
- On session reconnect, the servername extension may be absent.
*/
if (type == TLSEXT_TYPE_server_name)
{
unsigned char *sdata;
int servname_type;
int dsize;
if (size < 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
n2s(data,dsize);
size -= 2;
if (dsize > size )
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
sdata = data;
while (dsize > 3)
{
servname_type = *(sdata++);
n2s(sdata,len);
dsize -= 3;
if (len > dsize)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->servername_done == 0)
switch (servname_type)
{
case TLSEXT_NAMETYPE_host_name:
if (s->session->tlsext_hostname == NULL)
{
if (len > TLSEXT_MAXLEN_host_name ||
((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL))
{
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
memcpy(s->session->tlsext_hostname, sdata, len);
s->session->tlsext_hostname[len]='\0';
if (strlen(s->session->tlsext_hostname) != len) {
OPENSSL_free(s->session->tlsext_hostname);
s->session->tlsext_hostname = NULL;
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
s->servername_done = 1;
}
else
s->servername_done = strlen(s->session->tlsext_hostname) == len
&& strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
break;
default:
break;
}
dsize -= len;
}
if (dsize != 0)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats)
{
unsigned char *sdata = data;
int ecpointformatlist_length = *(sdata++);
if (ecpointformatlist_length != size - 1)
{
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = 0;
if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
#if 0
fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ecpointformatlist (length=%i) ", s->session->tlsext_ecpointformatlist_length);
sdata = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
fprintf(stderr,"%i ",*(sdata++));
fprintf(stderr,"\n");
#endif
}
else if (type == TLSEXT_TYPE_elliptic_curves)
{
unsigned char *sdata = data;
int ellipticcurvelist_length = (*(sdata++) << 8);
ellipticcurvelist_length += (*(sdata++));
if (ellipticcurvelist_length != size - 2)
{
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->session->tlsext_ellipticcurvelist_length = 0;
if (s->session->tlsext_ellipticcurvelist != NULL) OPENSSL_free(s->session->tlsext_ellipticcurvelist);
if ((s->session->tlsext_ellipticcurvelist = OPENSSL_malloc(ellipticcurvelist_length)) == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ellipticcurvelist_length = ellipticcurvelist_length;
memcpy(s->session->tlsext_ellipticcurvelist, sdata, ellipticcurvelist_length);
#if 0
fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ellipticcurvelist (length=%i) ", s->session->tlsext_ellipticcurvelist_length);
sdata = s->session->tlsext_ellipticcurvelist;
for (i = 0; i < s->session->tlsext_ellipticcurvelist_length; i++)
fprintf(stderr,"%i ",*(sdata++));
fprintf(stderr,"\n");
#endif
}
#endif /* OPENSSL_NO_EC */
#ifdef TLSEXT_TYPE_opaque_prf_input
else if (type == TLSEXT_TYPE_opaque_prf_input)
{
unsigned char *sdata = data;
if (size < 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
n2s(sdata, s->s3->client_opaque_prf_input_len);
if (s->s3->client_opaque_prf_input_len != size - 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
OPENSSL_free(s->s3->client_opaque_prf_input);
if (s->s3->client_opaque_prf_input_len == 0)
s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
else
s->s3->client_opaque_prf_input = BUF_memdup(sdata, s->s3->client_opaque_prf_input_len);
if (s->s3->client_opaque_prf_input == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
#endif
else if (type == TLSEXT_TYPE_status_request
&& s->ctx->tlsext_status_cb)
{
if (size < 5)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
s->tlsext_status_type = *data++;
size--;
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
{
const unsigned char *sdata;
int dsize;
/* Read in responder_id_list */
n2s(data,dsize);
size -= 2;
if (dsize > size )
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while (dsize > 0)
{
OCSP_RESPID *id;
int idsize;
if (dsize < 4)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
n2s(data, idsize);
dsize -= 2 + idsize;
if (dsize < 0)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
sdata = data;
data += idsize;
id = d2i_OCSP_RESPID(NULL,
&sdata, idsize);
if (!id)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (data != sdata)
{
OCSP_RESPID_free(id);
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->tlsext_ocsp_ids
&& !(s->tlsext_ocsp_ids =
sk_OCSP_RESPID_new_null()))
{
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
if (!sk_OCSP_RESPID_push(
s->tlsext_ocsp_ids, id))
{
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Read in request_extensions */
n2s(data,dsize);
size -= 2;
if (dsize > size)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
sdata = data;
if (dsize > 0)
{
s->tlsext_ocsp_exts =
d2i_X509_EXTENSIONS(NULL,
&sdata, dsize);
if (!s->tlsext_ocsp_exts
|| (data + dsize != sdata))
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
/* We don't know what to do with any other type
* so ignore it.
*/
else
s->tlsext_status_type = -1;
}
/* session ticket processed earlier */
data+=size;
}
*p = data;
return 1;
}
int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
{
unsigned short type;
unsigned short size;
unsigned short len;
unsigned char *data = *p;
int tlsext_servername = 0;
if (data >= (d+n-2))
return 1;
n2s(data,len);
while(data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
return 1;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size,
s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_server_name)
{
if (s->tlsext_hostname == NULL || size > 0)
{
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
tlsext_servername = 1;
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats)
{
unsigned char *sdata = data;
int ecpointformatlist_length = *(sdata++);
if (ecpointformatlist_length != size - 1)
{
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = 0;
if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
#if 0
fprintf(stderr,"ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
sdata = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
fprintf(stderr,"%i ",*(sdata++));
fprintf(stderr,"\n");
#endif
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket)
{
if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
|| (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
#ifdef TLSEXT_TYPE_opaque_prf_input
else if (type == TLSEXT_TYPE_opaque_prf_input)
{
unsigned char *sdata = data;
if (size < 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
n2s(sdata, s->s3->server_opaque_prf_input_len);
if (s->s3->server_opaque_prf_input_len != size - 2)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
OPENSSL_free(s->s3->server_opaque_prf_input);
if (s->s3->server_opaque_prf_input_len == 0)
s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
else
s->s3->server_opaque_prf_input = BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
if (s->s3->server_opaque_prf_input == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
#endif
else if (type == TLSEXT_TYPE_status_request)
{
/* MUST be empty and only sent if we've requested
* a status request message.
*/
if ((s->tlsext_status_type == -1) || (size > 0))
{
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set flag to expect CertificateStatus message */
s->tlsext_status_expected = 1;
}
data+=size;
}
if (data != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && tlsext_servername == 1)
{
if (s->tlsext_hostname)
{
if (s->session->tlsext_hostname == NULL)
{
s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
if (!s->session->tlsext_hostname)
{
*al = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
}
else
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
*p = data;
return 1;
}
int ssl_prepare_clienthello_tlsext(SSL *s)
{
#ifndef OPENSSL_NO_EC
/* If we are client and using an elliptic curve cryptography cipher suite, send the point formats
* and elliptic curves we support.
*/
int using_ecc = 0;
int i;
unsigned char *j;
unsigned long alg_k, alg_a;
STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++)
{
SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
alg_k = c->algorithm_mkey;
alg_a = c->algorithm_auth;
if ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe) || (alg_a & SSL_aECDSA)))
{
using_ecc = 1;
break;
}
}
using_ecc = using_ecc && (s->version == TLS1_VERSION);
if (using_ecc)
{
if (s->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->tlsext_ecpointformatlist);
if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(3)) == NULL)
{
SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
return -1;
}
s->tlsext_ecpointformatlist_length = 3;
s->tlsext_ecpointformatlist[0] = TLSEXT_ECPOINTFORMAT_uncompressed;
s->tlsext_ecpointformatlist[1] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
s->tlsext_ecpointformatlist[2] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
/* we support all named elliptic curves in draft-ietf-tls-ecc-12 */
if (s->tlsext_ellipticcurvelist != NULL) OPENSSL_free(s->tlsext_ellipticcurvelist);
s->tlsext_ellipticcurvelist_length = sizeof(nid_list)/sizeof(nid_list[0]) * 2;
if ((s->tlsext_ellipticcurvelist = OPENSSL_malloc(s->tlsext_ellipticcurvelist_length)) == NULL)
{
s->tlsext_ellipticcurvelist_length = 0;
SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
return -1;
}
for (i = 1, j = s->tlsext_ellipticcurvelist; (unsigned int)i <=
sizeof(nid_list)/sizeof(nid_list[0]); i++)
s2n(i,j);
}
#endif /* OPENSSL_NO_EC */
#ifdef TLSEXT_TYPE_opaque_prf_input
{
int r = 1;
if (s->ctx->tlsext_opaque_prf_input_callback != 0)
{
r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
if (!r)
return -1;
}
if (s->tlsext_opaque_prf_input != NULL)
{
if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
OPENSSL_free(s->s3->client_opaque_prf_input);
if (s->tlsext_opaque_prf_input_len == 0)
s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
else
s->s3->client_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
if (s->s3->client_opaque_prf_input == NULL)
{
SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
return -1;
}
s->s3->client_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
}
if (r == 2)
/* at callback's request, insist on receiving an appropriate server opaque PRF input */
s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
}
#endif
return 1;
}
int ssl_prepare_serverhello_tlsext(SSL *s)
{
#ifndef OPENSSL_NO_EC
/* If we are server and using an ECC cipher suite, send the point formats we support
* if the client sent us an ECPointsFormat extension. Note that the server is not
* supposed to send an EllipticCurves extension.
*/
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
int using_ecc = (alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA);
using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
if (using_ecc)
{
if (s->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->tlsext_ecpointformatlist);
if ((s->tlsext_ecpointformatlist = OPENSSL_malloc(3)) == NULL)
{
SSLerr(SSL_F_SSL_PREPARE_SERVERHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
return -1;
}
s->tlsext_ecpointformatlist_length = 3;
s->tlsext_ecpointformatlist[0] = TLSEXT_ECPOINTFORMAT_uncompressed;
s->tlsext_ecpointformatlist[1] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
s->tlsext_ecpointformatlist[2] = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
}
#endif /* OPENSSL_NO_EC */
return 1;
}
int ssl_check_clienthello_tlsext(SSL *s)
{
int ret=SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/* The handling of the ECPointFormats extension is done elsewhere, namely in
* ssl3_choose_cipher in s3_lib.c.
*/
/* The handling of the EllipticCurves extension is done elsewhere, namely in
* ssl3_choose_cipher in s3_lib.c.
*/
#endif
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
/* If status request then ask callback what to do.
* Note: this must be called after servername callbacks in case
* the certificate has changed.
*/
if ((s->tlsext_status_type != -1) && s->ctx->tlsext_status_cb)
{
int r;
r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
switch (r)
{
/* We don't want to send a status request response */
case SSL_TLSEXT_ERR_NOACK:
s->tlsext_status_expected = 0;
break;
/* status request response should be sent */
case SSL_TLSEXT_ERR_OK:
if (s->tlsext_ocsp_resp)
s->tlsext_status_expected = 1;
else
s->tlsext_status_expected = 0;
break;
/* something bad happened */
case SSL_TLSEXT_ERR_ALERT_FATAL:
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
}
else
s->tlsext_status_expected = 0;
#ifdef TLSEXT_TYPE_opaque_prf_input
{
/* This sort of belongs into ssl_prepare_serverhello_tlsext(),
* but we might be sending an alert in response to the client hello,
* so this has to happen here in ssl_check_clienthello_tlsext(). */
int r = 1;
if (s->ctx->tlsext_opaque_prf_input_callback != 0)
{
r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
if (!r)
{
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
}
if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
OPENSSL_free(s->s3->server_opaque_prf_input);
s->s3->server_opaque_prf_input = NULL;
if (s->tlsext_opaque_prf_input != NULL)
{
if (s->s3->client_opaque_prf_input != NULL &&
s->s3->client_opaque_prf_input_len == s->tlsext_opaque_prf_input_len)
{
/* can only use this extension if we have a server opaque PRF input
* of the same length as the client opaque PRF input! */
if (s->tlsext_opaque_prf_input_len == 0)
s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
else
s->s3->server_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
if (s->s3->server_opaque_prf_input == NULL)
{
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
}
}
if (r == 2 && s->s3->server_opaque_prf_input == NULL)
{
/* The callback wants to enforce use of the extension,
* but we can't do that with the client opaque PRF input;
* abort the handshake.
*/
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_HANDSHAKE_FAILURE;
}
}
#endif
err:
switch (ret)
{
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s,SSL3_AL_WARNING,al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done=0;
default:
return 1;
}
}
int ssl_check_serverhello_tlsext(SSL *s)
{
int ret=SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/* If we are client and using an elliptic curve cryptography cipher suite, then server
* must return a an EC point formats lists containing uncompressed.
*/
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
if ((s->tlsext_ecpointformatlist != NULL) && (s->tlsext_ecpointformatlist_length > 0) &&
((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA)))
{
/* we are using an ECC cipher */
size_t i;
unsigned char *list;
int found_uncompressed = 0;
if ((s->session->tlsext_ecpointformatlist == NULL) || (s->session->tlsext_ecpointformatlist_length == 0))
{
SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
return -1;
}
list = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
{
if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed)
{
found_uncompressed = 1;
break;
}
}
if (!found_uncompressed)
{
SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
return -1;
}
}
ret = SSL_TLSEXT_ERR_OK;
#endif /* OPENSSL_NO_EC */
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)
ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
#ifdef TLSEXT_TYPE_opaque_prf_input
if (s->s3->server_opaque_prf_input_len > 0)
{
/* This case may indicate that we, as a client, want to insist on using opaque PRF inputs.
* So first verify that we really have a value from the server too. */
if (s->s3->server_opaque_prf_input == NULL)
{
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_HANDSHAKE_FAILURE;
}
/* Anytime the server *has* sent an opaque PRF input, we need to check
* that we have a client opaque PRF input of the same size. */
if (s->s3->client_opaque_prf_input == NULL ||
s->s3->client_opaque_prf_input_len != s->s3->server_opaque_prf_input_len)
{
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_ILLEGAL_PARAMETER;
}
}
#endif
/* If we've requested certificate status and we wont get one
* tell the callback
*/
if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
&& s->ctx->tlsext_status_cb)
{
int r;
/* Set resp to NULL, resplen to -1 so callback knows
* there is no response.
*/
if (s->tlsext_ocsp_resp)
{
OPENSSL_free(s->tlsext_ocsp_resp);
s->tlsext_ocsp_resp = NULL;
}
s->tlsext_ocsp_resplen = -1;
r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
if (r == 0)
{
al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
}
if (r < 0)
{
al = SSL_AD_INTERNAL_ERROR;
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
}
}
switch (ret)
{
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s,SSL3_AL_WARNING,al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done=0;
default:
return 1;
}
}
/* Since the server cache lookup is done early on in the processing of client
* hello and other operations depend on the result we need to handle any TLS
* session ticket extension at the same time.
*/
int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
const unsigned char *limit, SSL_SESSION **ret)
{
/* Point after session ID in client hello */
const unsigned char *p = session_id + len;
unsigned short i;
if ((s->version <= SSL3_VERSION) || !limit)
return 1;
if (p >= limit)
return -1;
/* Skip past cipher list */
n2s(p, i);
p+= i;
if (p >= limit)
return -1;
/* Skip past compression algorithm list */
i = *(p++);
p += i;
if (p > limit)
return -1;
/* Now at start of extensions */
if ((p + 2) >= limit)
return 1;
n2s(p, i);
while ((p + 4) <= limit)
{
unsigned short type, size;
n2s(p, type);
n2s(p, size);
if (p + size > limit)
return 1;
if (type == TLSEXT_TYPE_session_ticket)
{
/* If tickets disabled indicate cache miss which will
* trigger a full handshake
*/
if (SSL_get_options(s) & SSL_OP_NO_TICKET)
return 0;
/* If zero length not client will accept a ticket
* and indicate cache miss to trigger full handshake
*/
if (size == 0)
{
s->tlsext_ticket_expected = 1;
return 0; /* Cache miss */
}
return tls_decrypt_ticket(s, p, size, session_id, len,
ret);
}
p += size;
}
return 1;
}
static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
const unsigned char *sess_id, int sesslen,
SSL_SESSION **psess)
{
SSL_SESSION *sess;
unsigned char *sdec;
const unsigned char *p;
int slen, mlen, renew_ticket = 0;
unsigned char tick_hmac[EVP_MAX_MD_SIZE];
HMAC_CTX hctx;
EVP_CIPHER_CTX ctx;
/* Need at least keyname + iv + some encrypted data */
if (eticklen < 48)
goto tickerr;
/* Initialize session ticket encryption and HMAC contexts */
HMAC_CTX_init(&hctx);
EVP_CIPHER_CTX_init(&ctx);
if (s->ctx->tlsext_ticket_key_cb)
{
unsigned char *nctick = (unsigned char *)etick;
int rv = s->ctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
&ctx, &hctx, 0);
if (rv < 0)
return -1;
if (rv == 0)
goto tickerr;
if (rv == 2)
renew_ticket = 1;
}
else
{
/* Check key name matches */
if (memcmp(etick, s->ctx->tlsext_tick_key_name, 16))
goto tickerr;
HMAC_Init_ex(&hctx, s->ctx->tlsext_tick_hmac_key, 16,
tlsext_tick_md(), NULL);
EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
s->ctx->tlsext_tick_aes_key, etick + 16);
}
/* Attempt to process session ticket, first conduct sanity and
* integrity checks on ticket.
*/
mlen = HMAC_size(&hctx);
eticklen -= mlen;
/* Check HMAC of encrypted ticket */
HMAC_Update(&hctx, etick, eticklen);
HMAC_Final(&hctx, tick_hmac, NULL);
HMAC_CTX_cleanup(&hctx);
if (memcmp(tick_hmac, etick + eticklen, mlen))
goto tickerr;
/* Attempt to decrypt session data */
/* Move p after IV to start of encrypted ticket, update length */
p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
sdec = OPENSSL_malloc(eticklen);
if (!sdec)
{
EVP_CIPHER_CTX_cleanup(&ctx);
return -1;
}
EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen);
if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0)
goto tickerr;
slen += mlen;
EVP_CIPHER_CTX_cleanup(&ctx);
p = sdec;
sess = d2i_SSL_SESSION(NULL, &p, slen);
OPENSSL_free(sdec);
if (sess)
{
/* The session ID if non-empty is used by some clients to
* detect that the ticket has been accepted. So we copy it to
* the session structure. If it is empty set length to zero
* as required by standard.
*/
if (sesslen)
memcpy(sess->session_id, sess_id, sesslen);
sess->session_id_length = sesslen;
*psess = sess;
s->tlsext_ticket_expected = renew_ticket;
return 1;
}
/* If session decrypt failure indicate a cache miss and set state to
* send a new ticket
*/
tickerr:
s->tlsext_ticket_expected = 1;
return 0;
}
#endif
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