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openssl/ssl/t1_lib.c
Ben Laurie 2708813166 Add and use a constant-time memcmp. 
This change adds CRYPTO_memcmp, which compares two vectors of bytes in
an amount of time that's independent of their contents. It also changes
several MAC compares in the code to use this over the standard memcmp,
which may leak information about the size of a matching prefix.
(cherry picked from commit 2ee798880a)

Conflicts:
	crypto/crypto.h
	ssl/t1_lib.c
(cherry picked from commit dc406b59f3169fe191e58906df08dce97edb727c)

Conflicts:
	crypto/crypto.h
	ssl/d1_pkt.c
	ssl/s3_pkt.c
2013-02-05 16:50:32 +00:00

1058 lines
26 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.]
*/
#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 (CRYPTO_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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