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openssl/ssl/t1_lib.c
Dr. Stephen Henson 71a2440ee5 backport OCSP fix enhancement
2012-10-05 13:02:31 +00:00

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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.]
*/
#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);
}
IMPLEMENT_tls1_meth_func(tlsv1_base_method,
ssl_undefined_function,
ssl_undefined_function,
ssl_bad_method)
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;
}
#if 0
long tls1_ctrl(SSL *s, int cmd, long larg, char *parg)
{
return(0);
}
long tls1_callback_ctrl(SSL *s, int cmd, void *(*fp)())
{
return(0);
}
#endif
#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;
/* don't add extensions for SSLv3 unless doing secure renegotiation */
if (s->client_version == SSL3_VERSION
&& !s->s3->send_connection_binding)
return 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;
}
/* Add RI if renegotiating */
if (s->new_session)
{
int el;
if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
{
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if((limit - p - 4 - el) < 0) return NULL;
s2n(TLSEXT_TYPE_renegotiate,ret);
s2n(el,ret);
if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
{
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
{
int ticklen;
if (!s->new_session && 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 (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;
}
}
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp &&
s->version != DTLS1_VERSION)
{
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;
/* don't add extensions for SSLv3, unless doing secure renegotiation */
if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
return 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 (limit - ret - 4 < 0) return NULL;
s2n(TLSEXT_TYPE_server_name,ret);
s2n(0,ret);
}
if(s->s3->send_connection_binding)
{
int el;
if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
{
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if((limit - p - 4 - el) < 0) return NULL;
s2n(TLSEXT_TYPE_renegotiate,ret);
s2n(el,ret);
if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
{
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
if (s->tlsext_ticket_expected
&& !(SSL_get_options(s) & SSL_OP_NO_TICKET))
{
if (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);
}
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;
int renegotiate_seen = 0;
s->servername_done = 0;
s->tlsext_status_type = -1;
if (data >= (d+n-2))
goto ri_check;
n2s(data,len);
if (data > (d+n-len))
goto ri_check;
while (data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
goto ri_check;
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->hit)
{
if(s->session->tlsext_hostname)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (len > TLSEXT_MAXLEN_host_name)
{
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL)
{
*al = TLS1_AD_INTERNAL_ERROR;
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 = s->session->tlsext_hostname
&& 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;
}
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
return 0;
renegotiate_seen = 1;
}
else if (type == TLSEXT_TYPE_status_request &&
s->version != DTLS1_VERSION && 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;
size -= 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 */
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;
if (dsize > 0)
{
if (s->tlsext_ocsp_exts)
{
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
X509_EXTENSION_free);
}
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;
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->new_session &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
{
unsigned short length;
unsigned short type;
unsigned short size;
unsigned char *data = *p;
int tlsext_servername = 0;
int renegotiate_seen = 0;
if (data >= (d+n-2))
goto ri_check;
n2s(data,length);
if (data+length != d+n)
{
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while(data <= (d+n-4))
{
n2s(data,type);
n2s(data,size);
if (data+size > (d+n))
goto ri_check;
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;
}
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;
}
else if (type == TLSEXT_TYPE_status_request &&
s->version != DTLS1_VERSION)
{
/* 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;
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
return 0;
renegotiate_seen = 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;
ri_check:
/* Determine if we need to see RI. Strictly speaking if we want to
* avoid an attack we should *always* see RI even on initial server
* hello because the client doesn't see any renegotiation during an
* attack. However this would mean we could not connect to any server
* which doesn't support RI so for the immediate future tolerate RI
* absence on initial connect only.
*/
if (!renegotiate_seen
&& !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
int ssl_check_clienthello_tlsext_early(SSL *s)
{
int ret=SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
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);
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_clienthello_tlsext_late(SSL *s)
{
int ret = SSL_TLSEXT_ERR_OK;
int al;
/* If status request then ask callback what to do.
* Note: this must be called after servername callbacks in case
* the certificate has changed, and must be called after the cipher
* has been chosen because this may influence which certificate is sent
*/
if (s->tlsext_status_type != -1 && s->ctx && s->ctx->tlsext_status_cb)
{
int r;
CERT_PKEY *certpkey;
certpkey = ssl_get_server_send_pkey(s);
/* If no certificate can't return certificate status */
if (certpkey == NULL)
{
s->tlsext_status_expected = 0;
return 1;
}
/* Set current certificate to one we will use so
* SSL_get_certificate et al can pick it up.
*/
s->cert->key = certpkey;
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;
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;
default:
return 1;
}
}
int ssl_check_serverhello_tlsext(SSL *s)
{
int ret=SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
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 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 tickets disabled behave as if no ticket present
* to permit stateful resumption.
*/
if (SSL_get_options(s) & SSL_OP_NO_TICKET)
return 1;
if ((s->version <= SSL3_VERSION) || !limit)
return 1;
if (p >= limit)
return -1;
/* Skip past DTLS cookie */
if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER)
{
i = *(p++);
p+= i;
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 zero length note 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;
SSL_CTX *tctx = s->initial_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 (tctx->tlsext_ticket_key_cb)
{
unsigned char *nctick = (unsigned char *)etick;
int rv = tctx->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, tctx->tlsext_tick_key_name, 16))
goto tickerr;
HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
tlsext_tick_md(), NULL);
EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
tctx->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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