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openssl/ssl/t1_lib.c
Matt Caswell f141376ae2 Change functions to pass in a limit rather than calculate it 
Some extension handling functions were passing in a pointer to the start
of the data, plus the length in order to calculate the end, rather than
just passing in the end to start with. This change makes things a little
more readable.

Reviewed-by: Emilia Käsper <emilia@openssl.org>

Conflicts:
	ssl/s3_srvr.c
	ssl/ssl_locl.h
	ssl/t1_lib.c
2015-10-05 19:52:38 +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 *limit)
{
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 >= (limit - 2))
return;
data += 2;
if (data > (limit - 4))
return;
n2s(data, type);
n2s(data, size);
if (type != TLSEXT_TYPE_server_name)
return;
if (data + size > limit)
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 != limit)
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 != limit)
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 *limit, 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, limit);
# 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 == limit)
goto ri_check;
if (data > (limit - 2))
goto err;
n2s(data, len);
if (data + len != limit)
goto err;
while (data <= (limit - 4)) {
n2s(data, type);
n2s(data, size);
if (data + size > (limit))
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 != limit)
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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