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openssl/ssl/t1_lib.c
Matt Caswell 72df35acf2 Tighten extension handling 
This adds additional checks to the processing of extensions in a ClientHello
to ensure that either no extensions are present, or if they are then they
take up the exact amount of space expected.

With thanks to the Open Crypto Audit Project for reporting this issue.

Reviewed-by: Stephen Henson <steve@openssl.org>

Conflicts:
	ssl/t1_lib.c
2015-06-10 10:32:05 +01:00

2697 lines
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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 <openssl/rand.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,
tls1_export_keying_material,
};
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)
{
#ifndef OPENSSL_NO_TLSEXT
if (s->tlsext_session_ticket) {
OPENSSL_free(s->tlsext_session_ticket);
}
#endif /* OPENSSL_NO_TLSEXT */
ssl3_free(s);
}
void tls1_clear(SSL *s)
{
ssl3_clear(s);
s->version = s->method->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) */
};
static int pref_list[] = {
# ifndef OPENSSL_NO_EC2M
NID_sect571r1, /* sect571r1 (14) */
NID_sect571k1, /* sect571k1 (13) */
# endif
NID_secp521r1, /* secp521r1 (25) */
# ifndef OPENSSL_NO_EC2M
NID_sect409k1, /* sect409k1 (11) */
NID_sect409r1, /* sect409r1 (12) */
# endif
NID_secp384r1, /* secp384r1 (24) */
# ifndef OPENSSL_NO_EC2M
NID_sect283k1, /* sect283k1 (9) */
NID_sect283r1, /* sect283r1 (10) */
# endif
NID_secp256k1, /* secp256k1 (22) */
NID_X9_62_prime256v1, /* secp256r1 (23) */
# ifndef OPENSSL_NO_EC2M
NID_sect239k1, /* sect239k1 (8) */
NID_sect233k1, /* sect233k1 (6) */
NID_sect233r1, /* sect233r1 (7) */
# endif
NID_secp224k1, /* secp224k1 (20) */
NID_secp224r1, /* secp224r1 (21) */
# ifndef OPENSSL_NO_EC2M
NID_sect193r1, /* sect193r1 (4) */
NID_sect193r2, /* sect193r2 (5) */
# endif
NID_secp192k1, /* secp192k1 (18) */
NID_X9_62_prime192v1, /* secp192r1 (19) */
# ifndef OPENSSL_NO_EC2M
NID_sect163k1, /* sect163k1 (1) */
NID_sect163r1, /* sect163r1 (2) */
NID_sect163r2, /* sect163r2 (3) */
# endif
NID_secp160k1, /* secp160k1 (15) */
NID_secp160r1, /* secp160r1 (16) */
NID_secp160r2, /* secp160r2 (17) */
};
int tls1_ec_curve_id2nid(int curve_id)
{
/* ECC curves from RFC 4492 */
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 RFC 4492 */
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
/*
* List of supported signature algorithms and hashes. Should make this
* customisable at some point, for now include everything we support.
*/
# ifdef OPENSSL_NO_RSA
# define tlsext_sigalg_rsa(md) /* */
# else
# define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
# endif
# ifdef OPENSSL_NO_DSA
# define tlsext_sigalg_dsa(md) /* */
# else
# define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
# endif
# ifdef OPENSSL_NO_ECDSA
# define tlsext_sigalg_ecdsa(md)
/* */
# else
# define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
# endif
# define tlsext_sigalg(md) \
tlsext_sigalg_rsa(md) \
tlsext_sigalg_dsa(md) \
tlsext_sigalg_ecdsa(md)
static unsigned char tls12_sigalgs[] = {
# ifndef OPENSSL_NO_SHA512
tlsext_sigalg(TLSEXT_hash_sha512)
tlsext_sigalg(TLSEXT_hash_sha384)
# endif
# ifndef OPENSSL_NO_SHA256
tlsext_sigalg(TLSEXT_hash_sha256)
tlsext_sigalg(TLSEXT_hash_sha224)
# endif
# ifndef OPENSSL_NO_SHA
tlsext_sigalg(TLSEXT_hash_sha1)
# endif
};
int tls12_get_req_sig_algs(SSL *s, unsigned char *p)
{
size_t slen = sizeof(tls12_sigalgs);
if (p)
memcpy(p, tls12_sigalgs, slen);
return (int)slen;
}
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
/* don't add extensions for SSLv3 unless doing secure renegotiation */
if (s->client_version == SSL3_VERSION && !s->s3->send_connection_binding)
return orig;
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->renegotiate) {
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 - ret - 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;
}
# ifndef OPENSSL_NO_SRP
/* Add SRP username if there is one */
if (s->srp_ctx.login != NULL) { /* Add TLS extension SRP username to the
* Client Hello message */
int login_len = strlen(s->srp_ctx.login);
if (login_len > 255 || login_len == 0) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
/*-
* check for enough space.
* 4 for the srp type type and entension length
* 1 for the srp user identity
* + srp user identity length
*/
if ((limit - ret - 5 - login_len) < 0)
return NULL;
/* fill in the extension */
s2n(TLSEXT_TYPE_srp, ret);
s2n(login_len + 1, ret);
(*ret++) = (unsigned char)login_len;
memcpy(ret, s->srp_ctx.login, login_len);
ret += login_len;
}
# endif
# 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);
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->new_session && s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
else if (s->session && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data) {
ticklen = s->tlsext_session_ticket->length;
s->session->tlsext_tick = OPENSSL_malloc(ticklen);
if (!s->session->tlsext_tick)
return NULL;
memcpy(s->session->tlsext_tick,
s->tlsext_session_ticket->data, ticklen);
s->session->tlsext_ticklen = ticklen;
} else
ticklen = 0;
if (ticklen == 0 && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data == NULL)
goto skip_ext;
/*
* 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;
}
}
skip_ext:
if (TLS1_get_client_version(s) >= TLS1_2_VERSION) {
if ((size_t)(limit - ret) < sizeof(tls12_sigalgs) + 6)
return NULL;
s2n(TLSEXT_TYPE_signature_algorithms, ret);
s2n(sizeof(tls12_sigalgs) + 2, ret);
s2n(sizeof(tls12_sigalgs), ret);
memcpy(ret, tls12_sigalgs, sizeof(tls12_sigalgs));
ret += sizeof(tls12_sigalgs);
}
# ifdef TLSEXT_TYPE_opaque_prf_input
if (s->s3->client_opaque_prf_input != NULL && s->version != DTLS1_VERSION) {
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 &&
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);
}
# ifndef OPENSSL_NO_HEARTBEATS
/* Add Heartbeat extension */
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_TLSEXT_HB_ENABLED;
# endif
# ifndef OPENSSL_NO_NEXTPROTONEG
if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len) {
/*
* The client advertises an emtpy extension to indicate its support
* for Next Protocol Negotiation
*/
if (limit - ret - 4 < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(0, ret);
}
# endif
# ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) {
int el;
ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
# endif
/*
* Add padding to workaround bugs in F5 terminators. See
* https://tools.ietf.org/html/draft-agl-tls-padding-03 NB: because this
* code works out the length of all existing extensions it MUST always
* appear last.
*/
if (s->options & SSL_OP_TLSEXT_PADDING) {
int hlen = ret - (unsigned char *)s->init_buf->data;
/*
* The code in s23_clnt.c to build ClientHello messages includes the
* 5-byte record header in the buffer, while the code in s3_clnt.c
* does not.
*/
if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
hlen -= 5;
if (hlen > 0xff && hlen < 0x200) {
hlen = 0x200 - hlen;
if (hlen >= 4)
hlen -= 4;
else
hlen = 0;
s2n(TLSEXT_TYPE_padding, ret);
s2n(hlen, ret);
memset(ret, 0, hlen);
ret += hlen;
}
}
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
# ifndef OPENSSL_NO_NEXTPROTONEG
int next_proto_neg_seen;
# endif
/*
* don't add extensions for SSLv3, unless doing secure renegotiation
*/
if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
return orig;
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);
}
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 - ret - 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;
}
# 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 && s->version != DTLS1_VERSION) {
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
# ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && s->srtp_profile) {
int el;
ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
# 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;
}
# ifndef OPENSSL_NO_HEARTBEATS
/* Add Heartbeat extension if we've received one */
if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) {
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_TLSEXT_HB_ENABLED;
}
# endif
# ifndef OPENSSL_NO_NEXTPROTONEG
next_proto_neg_seen = s->s3->next_proto_neg_seen;
s->s3->next_proto_neg_seen = 0;
if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb) {
const unsigned char *npa;
unsigned int npalen;
int r;
r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
s->
ctx->next_protos_advertised_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
if ((long)(limit - ret - 4 - npalen) < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(npalen, ret);
memcpy(ret, npa, npalen);
ret += npalen;
s->s3->next_proto_neg_seen = 1;
}
}
# endif
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
# ifndef OPENSSL_NO_EC
/*-
* ssl_check_for_safari attempts to fingerprint Safari using OS X
* SecureTransport using the TLS extension block in |d|, of length |n|.
* Safari, since 10.6, sends exactly these extensions, in this order:
* SNI,
* elliptic_curves
* ec_point_formats
*
* We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
* but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
* Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
* 10.8..10.8.3 (which don't work).
*/
static void ssl_check_for_safari(SSL *s, const unsigned char *data,
const unsigned char *d, int n)
{
unsigned short type, size;
static const unsigned char kSafariExtensionsBlock[] = {
0x00, 0x0a, /* elliptic_curves extension */
0x00, 0x08, /* 8 bytes */
0x00, 0x06, /* 6 bytes of curve ids */
0x00, 0x17, /* P-256 */
0x00, 0x18, /* P-384 */
0x00, 0x19, /* P-521 */
0x00, 0x0b, /* ec_point_formats */
0x00, 0x02, /* 2 bytes */
0x01, /* 1 point format */
0x00, /* uncompressed */
};
/* The following is only present in TLS 1.2 */
static const unsigned char kSafariTLS12ExtensionsBlock[] = {
0x00, 0x0d, /* signature_algorithms */
0x00, 0x0c, /* 12 bytes */
0x00, 0x0a, /* 10 bytes */
0x05, 0x01, /* SHA-384/RSA */
0x04, 0x01, /* SHA-256/RSA */
0x02, 0x01, /* SHA-1/RSA */
0x04, 0x03, /* SHA-256/ECDSA */
0x02, 0x03, /* SHA-1/ECDSA */
};
if (data >= (d + n - 2))
return;
data += 2;
if (data > (d + n - 4))
return;
n2s(data, type);
n2s(data, size);
if (type != TLSEXT_TYPE_server_name)
return;
if (data + size > d + n)
return;
data += size;
if (TLS1_get_client_version(s) >= TLS1_2_VERSION) {
const size_t len1 = sizeof(kSafariExtensionsBlock);
const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
if (data + len1 + len2 != d + n)
return;
if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
return;
if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
return;
} else {
const size_t len = sizeof(kSafariExtensionsBlock);
if (data + len != d + n)
return;
if (memcmp(data, kSafariExtensionsBlock, len) != 0)
return;
}
s->s3->is_probably_safari = 1;
}
# endif /* !OPENSSL_NO_EC */
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;
int sigalg_seen = 0;
s->servername_done = 0;
s->tlsext_status_type = -1;
# ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
# endif
# ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
# endif
# ifndef OPENSSL_NO_EC
if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
ssl_check_for_safari(s, data, d, n);
# endif /* !OPENSSL_NO_EC */
# ifndef OPENSSL_NO_SRP
if (s->srp_ctx.login != NULL) {
OPENSSL_free(s->srp_ctx.login);
s->srp_ctx.login = NULL;
}
# endif
s->srtp_profile = NULL;
if (data >= (d + n - 2)) {
if (data != d + n)
goto err;
else
goto ri_check;
}
n2s(data, len);
if (data > (d + n - len))
goto err;
while (data <= (d + n - 4)) {
n2s(data, type);
n2s(data, size);
if (data + size > (d + n))
goto err;
# 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)
goto err;
n2s(data, dsize);
size -= 2;
if (dsize > size)
goto err;
sdata = data;
while (dsize > 3) {
servname_type = *(sdata++);
n2s(sdata, len);
dsize -= 3;
if (len > dsize)
goto err;
if (s->servername_done == 0)
switch (servname_type) {
case TLSEXT_NAMETYPE_host_name:
if (!s->hit) {
if (s->session->tlsext_hostname)
goto err;
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)
goto err;
}
# ifndef OPENSSL_NO_SRP
else if (type == TLSEXT_TYPE_srp) {
if (size == 0 || ((len = data[0])) != (size - 1))
goto err;
if (s->srp_ctx.login != NULL)
goto err;
if ((s->srp_ctx.login = OPENSSL_malloc(len + 1)) == NULL)
return -1;
memcpy(s->srp_ctx.login, &data[1], len);
s->srp_ctx.login[len] = '\0';
if (strlen(s->srp_ctx.login) != len)
goto err;
}
# endif
# 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)
goto err;
if (!s->hit) {
if (s->session->tlsext_ecpointformatlist) {
OPENSSL_free(s->session->tlsext_ecpointformatlist);
s->session->tlsext_ecpointformatlist = NULL;
}
s->session->tlsext_ecpointformatlist_length = 0;
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 ||
ellipticcurvelist_length < 1 ||
/* Each NamedCurve is 2 bytes. */
ellipticcurvelist_length & 1)
goto err;
if (!s->hit) {
if (s->session->tlsext_ellipticcurvelist)
goto err;
s->session->tlsext_ellipticcurvelist_length = 0;
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 &&
s->version != DTLS1_VERSION) {
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);
}
/* dummy byte just to get non-NULL */
if (s->s3->client_opaque_prf_input_len == 0)
s->s3->client_opaque_prf_input = OPENSSL_malloc(1);
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_session_ticket) {
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
{
*al = TLS1_AD_INTERNAL_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_signature_algorithms) {
int dsize;
if (sigalg_seen || size < 2)
goto err;
sigalg_seen = 1;
n2s(data, dsize);
size -= 2;
if (dsize != size || dsize & 1)
goto err;
if (!tls1_process_sigalgs(s, data, dsize))
goto err;
} else if (type == TLSEXT_TYPE_status_request &&
s->version != DTLS1_VERSION) {
if (size < 5)
goto err;
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)
goto err;
while (dsize > 0) {
OCSP_RESPID *id;
int idsize;
if (dsize < 4)
goto err;
n2s(data, idsize);
dsize -= 2 + idsize;
size -= 2 + idsize;
if (dsize < 0)
goto err;
sdata = data;
data += idsize;
id = d2i_OCSP_RESPID(NULL, &sdata, idsize);
if (!id)
goto err;
if (data != sdata) {
OCSP_RESPID_free(id);
goto err;
}
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)
goto err;
n2s(data, dsize);
size -= 2;
if (dsize != size)
goto err;
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))
goto err;
}
}
/*
* We don't know what to do with any other type * so ignore it.
*/
else
s->tlsext_status_type = -1;
}
# ifndef OPENSSL_NO_HEARTBEATS
else if (type == TLSEXT_TYPE_heartbeat) {
switch (data[0]) {
case 0x01: /* Client allows us to send HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
break;
case 0x02: /* Client doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
# endif
# ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
/*-
* We shouldn't accept this extension on a
* renegotiation.
*
* s->new_session will be set on renegotiation, but we
* probably shouldn't rely that it couldn't be set on
* the initial renegotation too in certain cases (when
* there's some other reason to disallow resuming an
* earlier session -- the current code won't be doing
* anything like that, but this might change).
*
* A valid sign that there's been a previous handshake
* in this connection is if s->s3->tmp.finish_md_len >
* 0. (We are talking about a check that will happen
* in the Hello protocol round, well before a new
* Finished message could have been computed.)
*/
s->s3->next_proto_neg_seen = 1;
}
# endif
/* session ticket processed earlier */
# ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
&& type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_clienthello_use_srtp_ext(s, data, size, al))
return 0;
}
# endif
data += size;
}
/* Spurious data on the end */
if (data != d + n)
goto err;
*p = data;
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->renegotiate &&
!(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;
err:
*al = SSL_AD_DECODE_ERROR;
return 0;
}
# ifndef OPENSSL_NO_NEXTPROTONEG
/*
* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
* elements of zero length are allowed and the set of elements must exactly
* fill the length of the block.
*/
static char ssl_next_proto_validate(unsigned char *d, unsigned len)
{
unsigned int off = 0;
while (off < len) {
if (d[off] == 0)
return 0;
off += d[off];
off++;
}
return off == len;
}
# endif
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;
# ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
# endif
s->tlsext_ticket_expected = 0;
# ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
# endif
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;
}
# 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 ||
ecpointformatlist_length < 1) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
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 (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
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 &&
s->version != DTLS1_VERSION) {
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) {
/* dummy byte just to get non-NULL */
s->s3->server_opaque_prf_input = OPENSSL_malloc(1);
} 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 &&
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;
}
# ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
unsigned char *selected;
unsigned char selected_len;
/* We must have requested it. */
if (s->ctx->next_proto_select_cb == NULL) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The data must be valid */
if (!ssl_next_proto_validate(data, size)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (s->
ctx->next_proto_select_cb(s, &selected, &selected_len, data,
size,
s->ctx->next_proto_select_cb_arg) !=
SSL_TLSEXT_ERR_OK) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->next_proto_negotiated = OPENSSL_malloc(selected_len);
if (!s->next_proto_negotiated) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
memcpy(s->next_proto_negotiated, selected, selected_len);
s->next_proto_negotiated_len = selected_len;
s->s3->next_proto_neg_seen = 1;
}
# endif
else if (type == TLSEXT_TYPE_renegotiate) {
if (!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
return 0;
renegotiate_seen = 1;
}
# ifndef OPENSSL_NO_HEARTBEATS
else if (type == TLSEXT_TYPE_heartbeat) {
switch (data[0]) {
case 0x01: /* Server allows us to send HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
break;
case 0x02: /* Server doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
# endif
# ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_serverhello_use_srtp_ext(s, data, size, al))
return 0;
}
# endif
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_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 RFC 4492 */
if (s->tlsext_ellipticcurvelist != NULL)
OPENSSL_free(s->tlsext_ellipticcurvelist);
s->tlsext_ellipticcurvelist_length =
sizeof(pref_list) / sizeof(pref_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 = 0, j = s->tlsext_ellipticcurvelist; (unsigned int)i <
sizeof(pref_list) / sizeof(pref_list[0]); i++) {
int id = tls1_ec_nid2curve_id(pref_list[i]);
s2n(id, 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) {
/* dummy byte just to get non-NULL */
s->s3->client_opaque_prf_input = OPENSSL_malloc(1);
} 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_early(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);
# 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_early().
*/
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) {
/* dummy byte just to get non-NULL */
s->s3->server_opaque_prf_input = OPENSSL_malloc(1);
} 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;
}
}
err:
# endif
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;
# ifndef OPENSSL_NO_EC
/*
* If we are client and using an elliptic curve cryptography cipher
* suite, then if server returns an EC point formats lists extension it
* must contain 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)
&& (s->session->tlsext_ecpointformatlist != NULL)
&& (s->session->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;
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 && 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 the
* ClientHello, and other operations depend on the result, we need to handle
* any TLS session ticket extension at the same time.
*
* session_id: points at the session ID in the ClientHello. This code will
* read past the end of this in order to parse out the session ticket
* extension, if any.
* len: the length of the session ID.
* limit: a pointer to the first byte after the ClientHello.
* ret: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* If s->tls_session_secret_cb is set then we are expecting a pre-shared key
* ciphersuite, in which case we have no use for session tickets and one will
* never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
*
* Returns:
* -1: fatal error, either from parsing or decrypting the ticket.
* 0: no ticket was found (or was ignored, based on settings).
* 1: a zero length extension was found, indicating that the client supports
* session tickets but doesn't currently have one to offer.
* 2: either s->tls_session_secret_cb was set, or a ticket was offered but
* couldn't be decrypted because of a non-fatal error.
* 3: a ticket was successfully decrypted and *ret was set.
*
* Side effects:
* Sets s->tlsext_ticket_expected to 1 if the server will have to issue
* a new session ticket to the client because the client indicated support
* (and s->tls_session_secret_cb is NULL) but the client either doesn't have
* a session ticket or we couldn't use the one it gave us, or if
* s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
* Otherwise, s->tlsext_ticket_expected is set to 0.
*/
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;
*ret = NULL;
s->tlsext_ticket_expected = 0;
/*
* If tickets disabled behave as if no ticket present to permit stateful
* resumption.
*/
if (SSL_get_options(s) & SSL_OP_NO_TICKET)
return 0;
if ((s->version <= SSL3_VERSION) || !limit)
return 0;
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 0;
n2s(p, i);
while ((p + 4) <= limit) {
unsigned short type, size;
n2s(p, type);
n2s(p, size);
if (p + size > limit)
return 0;
if (type == TLSEXT_TYPE_session_ticket) {
int r;
if (size == 0) {
/*
* The client will accept a ticket but doesn't currently have
* one.
*/
s->tlsext_ticket_expected = 1;
return 1;
}
if (s->tls_session_secret_cb) {
/*
* Indicate that the ticket couldn't be decrypted rather than
* generating the session from ticket now, trigger
* abbreviated handshake based on external mechanism to
* calculate the master secret later.
*/
return 2;
}
r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
switch (r) {
case 2: /* ticket couldn't be decrypted */
s->tlsext_ticket_expected = 1;
return 2;
case 3: /* ticket was decrypted */
return r;
case 4: /* ticket decrypted but need to renew */
s->tlsext_ticket_expected = 1;
return 3;
default: /* fatal error */
return -1;
}
}
p += size;
}
return 0;
}
/*-
* tls_decrypt_ticket attempts to decrypt a session ticket.
*
* etick: points to the body of the session ticket extension.
* eticklen: the length of the session tickets extenion.
* sess_id: points at the session ID.
* sesslen: the length of the session ID.
* psess: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* Returns:
* -1: fatal error, either from parsing or decrypting the ticket.
* 2: the ticket couldn't be decrypted.
* 3: a ticket was successfully decrypted and *psess was set.
* 4: same as 3, but the ticket needs to be renewed.
*/
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)
return 2;
/* 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)
return 2;
if (rv == 2)
renew_ticket = 1;
} else {
/* Check key name matches */
if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
return 2;
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);
if (mlen < 0) {
EVP_CIPHER_CTX_cleanup(&ctx);
return -1;
}
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)) {
EVP_CIPHER_CTX_cleanup(&ctx);
return 2;
}
/* 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) {
EVP_CIPHER_CTX_cleanup(&ctx);
OPENSSL_free(sdec);
return 2;
}
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;
if (renew_ticket)
return 4;
else
return 3;
}
ERR_clear_error();
/*
* For session parse failure, indicate that we need to send a new ticket.
*/
return 2;
}
/* Tables to translate from NIDs to TLS v1.2 ids */
typedef struct {
int nid;
int id;
} tls12_lookup;
static tls12_lookup tls12_md[] = {
# ifndef OPENSSL_NO_MD5
{NID_md5, TLSEXT_hash_md5},
# endif
# ifndef OPENSSL_NO_SHA
{NID_sha1, TLSEXT_hash_sha1},
# endif
# ifndef OPENSSL_NO_SHA256
{NID_sha224, TLSEXT_hash_sha224},
{NID_sha256, TLSEXT_hash_sha256},
# endif
# ifndef OPENSSL_NO_SHA512
{NID_sha384, TLSEXT_hash_sha384},
{NID_sha512, TLSEXT_hash_sha512}
# endif
};
static tls12_lookup tls12_sig[] = {
# ifndef OPENSSL_NO_RSA
{EVP_PKEY_RSA, TLSEXT_signature_rsa},
# endif
# ifndef OPENSSL_NO_DSA
{EVP_PKEY_DSA, TLSEXT_signature_dsa},
# endif
# ifndef OPENSSL_NO_ECDSA
{EVP_PKEY_EC, TLSEXT_signature_ecdsa}
# endif
};
static int tls12_find_id(int nid, tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if (table[i].nid == nid)
return table[i].id;
}
return -1;
}
# if 0
static int tls12_find_nid(int id, tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if (table[i].id == id)
return table[i].nid;
}
return -1;
}
# endif
int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk,
const EVP_MD *md)
{
int sig_id, md_id;
if (!md)
return 0;
md_id = tls12_find_id(EVP_MD_type(md), tls12_md,
sizeof(tls12_md) / sizeof(tls12_lookup));
if (md_id == -1)
return 0;
sig_id = tls12_get_sigid(pk);
if (sig_id == -1)
return 0;
p[0] = (unsigned char)md_id;
p[1] = (unsigned char)sig_id;
return 1;
}
int tls12_get_sigid(const EVP_PKEY *pk)
{
return tls12_find_id(pk->type, tls12_sig,
sizeof(tls12_sig) / sizeof(tls12_lookup));
}
const EVP_MD *tls12_get_hash(unsigned char hash_alg)
{
switch (hash_alg) {
# ifndef OPENSSL_NO_SHA
case TLSEXT_hash_sha1:
return EVP_sha1();
# endif
# ifndef OPENSSL_NO_SHA256
case TLSEXT_hash_sha224:
return EVP_sha224();
case TLSEXT_hash_sha256:
return EVP_sha256();
# endif
# ifndef OPENSSL_NO_SHA512
case TLSEXT_hash_sha384:
return EVP_sha384();
case TLSEXT_hash_sha512:
return EVP_sha512();
# endif
default:
return NULL;
}
}
/* Set preferred digest for each key type */
int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize)
{
int i, idx;
const EVP_MD *md;
CERT *c = s->cert;
/* Extension ignored for TLS versions below 1.2 */
if (TLS1_get_version(s) < TLS1_2_VERSION)
return 1;
/* Should never happen */
if (!c)
return 0;
c->pkeys[SSL_PKEY_DSA_SIGN].digest = NULL;
c->pkeys[SSL_PKEY_RSA_SIGN].digest = NULL;
c->pkeys[SSL_PKEY_RSA_ENC].digest = NULL;
c->pkeys[SSL_PKEY_ECC].digest = NULL;
for (i = 0; i < dsize; i += 2) {
unsigned char hash_alg = data[i], sig_alg = data[i + 1];
switch (sig_alg) {
# ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
idx = SSL_PKEY_RSA_SIGN;
break;
# endif
# ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
idx = SSL_PKEY_DSA_SIGN;
break;
# endif
# ifndef OPENSSL_NO_ECDSA
case TLSEXT_signature_ecdsa:
idx = SSL_PKEY_ECC;
break;
# endif
default:
continue;
}
if (c->pkeys[idx].digest == NULL) {
md = tls12_get_hash(hash_alg);
if (md) {
c->pkeys[idx].digest = md;
if (idx == SSL_PKEY_RSA_SIGN)
c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
}
}
}
/*
* Set any remaining keys to default values. NOTE: if alg is not
* supported it stays as NULL.
*/
# ifndef OPENSSL_NO_DSA
if (!c->pkeys[SSL_PKEY_DSA_SIGN].digest)
c->pkeys[SSL_PKEY_DSA_SIGN].digest = EVP_sha1();
# endif
# ifndef OPENSSL_NO_RSA
if (!c->pkeys[SSL_PKEY_RSA_SIGN].digest) {
c->pkeys[SSL_PKEY_RSA_SIGN].digest = EVP_sha1();
c->pkeys[SSL_PKEY_RSA_ENC].digest = EVP_sha1();
}
# endif
# ifndef OPENSSL_NO_ECDSA
if (!c->pkeys[SSL_PKEY_ECC].digest)
c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
# endif
return 1;
}
#endif
#ifndef OPENSSL_NO_HEARTBEATS
int tls1_process_heartbeat(SSL *s)
{
unsigned char *p = &s->s3->rrec.data[0], *pl;
unsigned short hbtype;
unsigned int payload;
unsigned int padding = 16; /* Use minimum padding */
if (s->msg_callback)
s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
&s->s3->rrec.data[0], s->s3->rrec.length,
s, s->msg_callback_arg);
/* Read type and payload length first */
if (1 + 2 + 16 > s->s3->rrec.length)
return 0; /* silently discard */
hbtype = *p++;
n2s(p, payload);
if (1 + 2 + payload + 16 > s->s3->rrec.length)
return 0; /* silently discard per RFC 6520 sec. 4 */
pl = p;
if (hbtype == TLS1_HB_REQUEST) {
unsigned char *buffer, *bp;
int r;
/*
* Allocate memory for the response, size is 1 bytes message type,
* plus 2 bytes payload length, plus payload, plus padding
*/
buffer = OPENSSL_malloc(1 + 2 + payload + padding);
bp = buffer;
/* Enter response type, length and copy payload */
*bp++ = TLS1_HB_RESPONSE;
s2n(payload, bp);
memcpy(bp, pl, payload);
bp += payload;
/* Random padding */
if (RAND_pseudo_bytes(bp, padding) < 0) {
OPENSSL_free(buffer);
return -1;
}
r = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buffer,
3 + payload + padding);
if (r >= 0 && s->msg_callback)
s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
buffer, 3 + payload + padding,
s, s->msg_callback_arg);
OPENSSL_free(buffer);
if (r < 0)
return r;
} else if (hbtype == TLS1_HB_RESPONSE) {
unsigned int seq;
/*
* We only send sequence numbers (2 bytes unsigned int), and 16
* random bytes, so we just try to read the sequence number
*/
n2s(pl, seq);
if (payload == 18 && seq == s->tlsext_hb_seq) {
s->tlsext_hb_seq++;
s->tlsext_hb_pending = 0;
}
}
return 0;
}
int tls1_heartbeat(SSL *s)
{
unsigned char *buf, *p;
int ret = -1;
unsigned int payload = 18; /* Sequence number + random bytes */
unsigned int padding = 16; /* Use minimum padding */
/* Only send if peer supports and accepts HB requests... */
if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
return -1;
}
/* ...and there is none in flight yet... */
if (s->tlsext_hb_pending) {
SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
return -1;
}
/* ...and no handshake in progress. */
if (SSL_in_init(s) || s->in_handshake) {
SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
return -1;
}
/*
* Check if padding is too long, payload and padding must not exceed 2^14
* - 3 = 16381 bytes in total.
*/
OPENSSL_assert(payload + padding <= 16381);
/*-
* Create HeartBeat message, we just use a sequence number
* as payload to distuingish different messages and add
* some random stuff.
* - Message Type, 1 byte
* - Payload Length, 2 bytes (unsigned int)
* - Payload, the sequence number (2 bytes uint)
* - Payload, random bytes (16 bytes uint)
* - Padding
*/
buf = OPENSSL_malloc(1 + 2 + payload + padding);
p = buf;
/* Message Type */
*p++ = TLS1_HB_REQUEST;
/* Payload length (18 bytes here) */
s2n(payload, p);
/* Sequence number */
s2n(s->tlsext_hb_seq, p);
/* 16 random bytes */
if (RAND_pseudo_bytes(p, 16) < 0) {
SSLerr(SSL_F_TLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
goto err;
}
p += 16;
/* Random padding */
if (RAND_pseudo_bytes(p, padding) < 0) {
SSLerr(SSL_F_TLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
goto err;
}
ret = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
if (ret >= 0) {
if (s->msg_callback)
s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
buf, 3 + payload + padding,
s, s->msg_callback_arg);
s->tlsext_hb_pending = 1;
}
err:
OPENSSL_free(buf);
return ret;
}
#endif
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