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boringssl/ssl/t1_lib.c
Adam Langley 5ba06a7532 Fix race condition in ssl_parse_serverhello_tlsext 
CVE-2014-3509

(Imported from upstream's 92aa73bcbfad44f9dd7997ae51537ac5d7dc201e)

Change-Id: Ibc681897251081ae5ebfea0ff6ca9defd73fe0f5
Reviewed-on: https://boringssl-review.googlesource.com/1441
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
2014-08-07 21:11:23 +00:00

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/* 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 <stdlib.h>
#include <assert.h>
#include <openssl/bytestring.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/rand.h>
#include "ssl_locl.h"
static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
const unsigned char *sess_id, int sesslen,
SSL_SESSION **psess);
static int ssl_check_clienthello_tlsext_early(SSL *s);
int ssl_check_serverhello_tlsext(SSL *s);
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,
0,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD TLSv1_1_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,
SSL_ENC_FLAG_EXPLICIT_IV,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD TLSv1_2_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,
SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_SHA256_PRF
|SSL_ENC_FLAG_TLS1_2_CIPHERS,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
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)
{
if (s->tlsext_session_ticket)
{
OPENSSL_free(s->tlsext_session_ticket);
}
ssl3_free(s);
}
void tls1_clear(SSL *s)
{
ssl3_clear(s);
s->version = s->method->version;
}
static int compare_uint16_t(const void *p1, const void *p2)
{
uint16_t u1 = *((const uint16_t*)p1);
uint16_t u2 = *((const uint16_t*)p2);
if (u1 < u2)
{
return -1;
}
else if (u1 > u2)
{
return 1;
}
else
{
return 0;
}
}
/* Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be more
* than one extension of the same type in a ClientHello or ServerHello. This
* function does an initial scan over the extensions block to filter those
* out. */
static int tls1_check_duplicate_extensions(const CBS *cbs)
{
CBS extensions = *cbs;
size_t num_extensions = 0, i = 0;
uint16_t *extension_types = NULL;
int ret = 0;
/* First pass: count the extensions. */
while (CBS_len(&extensions) > 0)
{
uint16_t type;
CBS extension;
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
{
goto done;
}
num_extensions++;
}
if (num_extensions == 0)
{
return 1;
}
extension_types = (uint16_t*)OPENSSL_malloc(sizeof(uint16_t) * num_extensions);
if (extension_types == NULL)
{
OPENSSL_PUT_ERROR(SSL, tls1_check_duplicate_extensions, ERR_R_MALLOC_FAILURE);
goto done;
}
/* Second pass: gather the extension types. */
extensions = *cbs;
for (i = 0; i < num_extensions; i++)
{
CBS extension;
if (!CBS_get_u16(&extensions, &extension_types[i]) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
{
/* This should not happen. */
goto done;
}
}
assert(CBS_len(&extensions) == 0);
/* Sort the extensions and make sure there are no duplicates. */
qsort(extension_types, num_extensions, sizeof(uint16_t), compare_uint16_t);
for (i = 1; i < num_extensions; i++)
{
if (extension_types[i-1] == extension_types[i])
{
goto done;
}
}
ret = 1;
done:
if (extension_types)
OPENSSL_free(extension_types);
return ret;
}
char ssl_early_callback_init(struct ssl_early_callback_ctx *ctx)
{
CBS client_hello, session_id, cipher_suites, compression_methods, extensions;
CBS_init(&client_hello, ctx->client_hello, ctx->client_hello_len);
/* Skip client version. */
if (!CBS_skip(&client_hello, 2))
return 0;
/* Skip client nonce. */
if (!CBS_skip(&client_hello, 32))
return 0;
/* Extract session_id. */
if (!CBS_get_u8_length_prefixed(&client_hello, &session_id))
return 0;
ctx->session_id = CBS_data(&session_id);
ctx->session_id_len = CBS_len(&session_id);
/* Skip past DTLS cookie */
if (ctx->ssl->version == DTLS1_VERSION || ctx->ssl->version == DTLS1_BAD_VER)
{
CBS cookie;
if (!CBS_get_u8_length_prefixed(&client_hello, &cookie))
return 0;
}
/* Extract cipher_suites. */
if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
CBS_len(&cipher_suites) < 2 ||
(CBS_len(&cipher_suites) & 1) != 0)
return 0;
ctx->cipher_suites = CBS_data(&cipher_suites);
ctx->cipher_suites_len = CBS_len(&cipher_suites);
/* Extract compression_methods. */
if (!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
CBS_len(&compression_methods) < 1)
return 0;
ctx->compression_methods = CBS_data(&compression_methods);
ctx->compression_methods_len = CBS_len(&compression_methods);
/* If the ClientHello ends here then it's valid, but doesn't have any
* extensions. (E.g. SSLv3.) */
if (CBS_len(&client_hello) == 0)
{
ctx->extensions = NULL;
ctx->extensions_len = 0;
return 1;
}
/* Extract extensions and check it is valid. */
if (!CBS_get_u16_length_prefixed(&client_hello, &extensions) ||
!tls1_check_duplicate_extensions(&extensions) ||
CBS_len(&client_hello) != 0)
return 0;
ctx->extensions = CBS_data(&extensions);
ctx->extensions_len = CBS_len(&extensions);
return 1;
}
char
SSL_early_callback_ctx_extension_get(const struct ssl_early_callback_ctx *ctx,
uint16_t extension_type,
const unsigned char **out_data,
size_t *out_len)
{
CBS extensions;
CBS_init(&extensions, ctx->extensions, ctx->extensions_len);
while (CBS_len(&extensions) != 0)
{
uint16_t type;
CBS extension;
/* Decode the next extension. */
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
return 0;
if (type == extension_type)
{
*out_data = CBS_data(&extension);
*out_len = CBS_len(&extension);
return 1;
}
}
return 0;
}
#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) */
NID_brainpoolP256r1, /* brainpoolP256r1 (26) */
NID_brainpoolP384r1, /* brainpoolP384r1 (27) */
NID_brainpoolP512r1 /* brainpool512r1 (28) */
};
static const uint8_t ecformats_default[] =
{
TLSEXT_ECPOINTFORMAT_uncompressed,
};
static const uint16_t eccurves_default[] =
{
23, /* secp256r1 (23) */
24, /* secp384r1 (24) */
25, /* secp521r1 (25) */
};
static const uint16_t suiteb_curves[] =
{
TLSEXT_curve_P_256,
TLSEXT_curve_P_384,
};
int tls1_ec_curve_id2nid(uint16_t curve_id)
{
/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
if (curve_id < 1 || curve_id > sizeof(nid_list)/sizeof(nid_list[0]))
return OBJ_undef;
return nid_list[curve_id-1];
}
uint16_t tls1_ec_nid2curve_id(int nid)
{
size_t i;
for (i = 0; i < sizeof(nid_list)/sizeof(nid_list[0]); i++)
{
/* nid_list[i] stores the NID corresponding to curve ID i+1. */
if (nid == nid_list[i])
return i + 1;
}
/* Use 0 for non-existent curve ID. Note: this assumes that curve ID 0
* will never be allocated. */
return 0;
}
/* tls1_get_curvelist sets |*out_curve_ids| and |*out_curve_ids_len| to the list
* of allowed curve IDs. If |get_client_curves| is non-zero, return the client
* curve list. Otherwise, return the preferred list. */
static void tls1_get_curvelist(SSL *s, int get_client_curves,
const uint16_t **out_curve_ids, size_t *out_curve_ids_len)
{
if (get_client_curves)
{
*out_curve_ids = s->session->tlsext_ellipticcurvelist;
*out_curve_ids_len = s->session->tlsext_ellipticcurvelist_length;
return;
}
/* For Suite B mode only include P-256, P-384 */
switch (tls1_suiteb(s))
{
case SSL_CERT_FLAG_SUITEB_128_LOS:
*out_curve_ids = suiteb_curves;
*out_curve_ids_len = sizeof(suiteb_curves) / sizeof(suiteb_curves[0]);
break;
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*out_curve_ids = suiteb_curves;
*out_curve_ids_len = 1;
break;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*out_curve_ids = suiteb_curves + 1;
*out_curve_ids_len = 1;
break;
default:
*out_curve_ids = s->tlsext_ellipticcurvelist;
*out_curve_ids_len = s->tlsext_ellipticcurvelist_length;
}
if (!*out_curve_ids)
{
*out_curve_ids = eccurves_default;
*out_curve_ids_len = sizeof(eccurves_default) / sizeof(eccurves_default[0]);
}
}
int tls1_check_curve(SSL *s, CBS *cbs, uint16_t *out_curve_id)
{
uint8_t curve_type;
uint16_t curve_id;
const uint16_t *curves;
size_t curves_len, i;
/* Only support named curves. */
if (!CBS_get_u8(cbs, &curve_type) ||
curve_type != NAMED_CURVE_TYPE ||
!CBS_get_u16(cbs, &curve_id))
return 0;
/* Check curve matches Suite B preferences */
if (tls1_suiteb(s))
{
unsigned long cid = s->s3->tmp.new_cipher->id;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
{
if (curve_id != TLSEXT_curve_P_256)
return 0;
}
else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
{
if (curve_id != TLSEXT_curve_P_384)
return 0;
}
else /* Should never happen */
return 0;
}
tls1_get_curvelist(s, 0, &curves, &curves_len);
for (i = 0; i < curves_len; i++)
{
if (curve_id == curves[i])
{
*out_curve_id = curve_id;
return 1;
}
}
return 0;
}
int tls1_get_shared_curve(SSL *s)
{
const uint16_t *pref, *supp;
size_t preflen, supplen, i, j;
/* Can't do anything on client side */
if (s->server == 0)
return NID_undef;
if (tls1_suiteb(s))
{
/* For Suite B ciphersuite determines curve: we
* already know these are acceptable due to previous
* checks.
*/
unsigned long cid = s->s3->tmp.new_cipher->id;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
return NID_X9_62_prime256v1; /* P-256 */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
return NID_secp384r1; /* P-384 */
/* Should never happen */
return NID_undef;
}
/* If not Suite B just return first preference shared curve */
tls1_get_curvelist(s, !!(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
&supp, &supplen);
tls1_get_curvelist(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
&pref, &preflen);
for (i = 0; i < preflen; i++)
{
for (j = 0; j < supplen; j++)
{
if (pref[i] == supp[j])
return tls1_ec_curve_id2nid(pref[i]);
}
}
return NID_undef;
}
/* NOTE: tls1_ec_curve_id2nid and tls1_set_curves assume that
*
* (a) 0 is not a valid curve ID.
*
* (b) The largest curve ID is 31.
*
* Those implementations must be revised before adding support for curve IDs
* that break these assumptions. */
OPENSSL_COMPILE_ASSERT(
(sizeof(nid_list) / sizeof(nid_list[0])) < 32, small_curve_ids);
int tls1_set_curves(uint16_t **out_curve_ids, size_t *out_curve_ids_len,
const int *curves, size_t ncurves)
{
uint16_t *curve_ids;
size_t i;
/* Bitmap of curves included to detect duplicates: only works
* while curve ids < 32
*/
uint32_t dup_list = 0;
curve_ids = (uint16_t*)OPENSSL_malloc(ncurves * sizeof(uint16_t));
if (!curve_ids)
return 0;
for (i = 0; i < ncurves; i++)
{
uint32_t idmask;
uint16_t id;
id = tls1_ec_nid2curve_id(curves[i]);
idmask = ((uint32_t)1) << id;
if (!id || (dup_list & idmask))
{
OPENSSL_free(curve_ids);
return 0;
}
dup_list |= idmask;
curve_ids[i] = id;
}
if (*out_curve_ids)
OPENSSL_free(*out_curve_ids);
*out_curve_ids = curve_ids;
*out_curve_ids_len = ncurves;
return 1;
}
/* tls1_curve_params_from_ec_key sets |*out_curve_id| and |*out_comp_id| to the
* TLS curve ID and point format, respectively, for |ec|. It returns one on
* success and zero on failure. */
static int tls1_curve_params_from_ec_key(uint16_t *out_curve_id, uint8_t *out_comp_id, EC_KEY *ec)
{
int nid;
uint16_t id;
const EC_GROUP *grp;
if (!ec)
return 0;
grp = EC_KEY_get0_group(ec);
if (!grp)
return 0;
/* Determine curve ID */
nid = EC_GROUP_get_curve_name(grp);
id = tls1_ec_nid2curve_id(nid);
if (!id)
return 0;
/* Set the named curve ID. Arbitrary explicit curves are not
* supported. */
*out_curve_id = id;
if (out_comp_id)
{
if (EC_KEY_get0_public_key(ec) == NULL)
return 0;
if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED)
*out_comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
else
*out_comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
}
return 1;
}
/* Check an EC key is compatible with extensions */
static int tls1_check_ec_key(SSL *s,
const uint16_t *curve_id, const uint8_t *comp_id)
{
const uint16_t *curves;
size_t curves_len, i;
int j;
/* If point formats extension present check it, otherwise everything
* is supported (see RFC4492).
*/
if (comp_id && s->session->tlsext_ecpointformatlist)
{
uint8_t *p = s->session->tlsext_ecpointformatlist;
size_t plen = s->session->tlsext_ecpointformatlist_length;
for (i = 0; i < plen; i++)
{
if (*comp_id == p[i])
break;
}
if (i == plen)
return 0;
}
if (!curve_id)
return 1;
/* Check curve is consistent with client and server preferences */
for (j = 0; j <= 1; j++)
{
tls1_get_curvelist(s, j, &curves, &curves_len);
for (i = 0; i < curves_len; i++)
{
if (curves[i] == *curve_id)
break;
}
if (i == curves_len)
return 0;
/* For clients can only check sent curve list */
if (!s->server)
return 1;
}
return 1;
}
static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
size_t *pformatslen)
{
/* If we have a custom point format list use it otherwise
* use default */
if (s->tlsext_ecpointformatlist)
{
*pformats = s->tlsext_ecpointformatlist;
*pformatslen = s->tlsext_ecpointformatlist_length;
}
else
{
*pformats = ecformats_default;
/* For Suite B we don't support char2 fields */
if (tls1_suiteb(s))
*pformatslen = sizeof(ecformats_default) - 1;
else
*pformatslen = sizeof(ecformats_default);
}
}
/* Check cert parameters compatible with extensions: currently just checks
* EC certificates have compatible curves and compression.
*/
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
uint8_t comp_id;
uint16_t curve_id;
EVP_PKEY *pkey;
int rv;
pkey = X509_get_pubkey(x);
if (!pkey)
return 0;
/* If not EC nothing to do */
if (pkey->type != EVP_PKEY_EC)
{
EVP_PKEY_free(pkey);
return 1;
}
rv = tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec);
EVP_PKEY_free(pkey);
if (!rv)
return 0;
/* Can't check curve_id for client certs as we don't have a
* supported curves extension.
*/
rv = tls1_check_ec_key(s, s->server ? &curve_id : NULL, &comp_id);
if (!rv)
return 0;
/* Special case for suite B. We *MUST* sign using SHA256+P-256 or
* SHA384+P-384, adjust digest if necessary.
*/
if (set_ee_md && tls1_suiteb(s))
{
int check_md;
size_t i;
CERT *c = s->cert;
/* Check to see we have necessary signing algorithm */
if (curve_id == TLSEXT_curve_P_256)
check_md = NID_ecdsa_with_SHA256;
else if (curve_id == TLSEXT_curve_P_384)
check_md = NID_ecdsa_with_SHA384;
else
return 0; /* Should never happen */
for (i = 0; i < c->shared_sigalgslen; i++)
if (check_md == c->shared_sigalgs[i].signandhash_nid)
break;
if (i == c->shared_sigalgslen)
return 0;
if (set_ee_md == 2)
{
if (check_md == NID_ecdsa_with_SHA256)
c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
else
c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
}
}
return rv;
}
/* Check EC temporary key is compatible with client extensions */
int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
{
uint16_t curve_id;
EC_KEY *ec = s->cert->ecdh_tmp;
#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
/* Allow any curve: not just those peer supports */
if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
return 1;
#endif
/* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384,
* no other curves permitted.
*/
if (tls1_suiteb(s))
{
/* Curve to check determined by ciphersuite */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
curve_id = TLSEXT_curve_P_256;
else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
curve_id = TLSEXT_curve_P_384;
else
return 0;
/* Check this curve is acceptable */
if (!tls1_check_ec_key(s, &curve_id, NULL))
return 0;
/* If auto or setting curve from callback assume OK */
if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
return 1;
/* Otherwise check curve is acceptable */
else
{
uint16_t curve_tmp;
if (!ec)
return 0;
if (!tls1_curve_params_from_ec_key(&curve_tmp, NULL, ec))
return 0;
if (curve_tmp == curve_id)
return 1;
return 0;
}
}
if (s->cert->ecdh_tmp_auto)
{
/* Need a shared curve */
return tls1_get_shared_curve(s) != NID_undef;
}
if (!ec)
{
if (s->cert->ecdh_tmp_cb)
return 1;
else
return 0;
}
if (!tls1_curve_params_from_ec_key(&curve_id, NULL, ec))
return 0;
/* Set this to allow use of invalid curves for testing */
#if 0
return 1;
#else
return tls1_check_ec_key(s, &curve_id, NULL);
#endif
}
#else
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
return 1;
}
#endif /* OPENSSL_NO_EC */
/* List of supported signature algorithms and hashes. Should make this
* customisable at some point, for now include everything we support.
*/
#define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
#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[] = {
tlsext_sigalg(TLSEXT_hash_sha512)
tlsext_sigalg(TLSEXT_hash_sha384)
tlsext_sigalg(TLSEXT_hash_sha256)
tlsext_sigalg(TLSEXT_hash_sha224)
#ifndef OPENSSL_NO_SHA
tlsext_sigalg(TLSEXT_hash_sha1)
#endif
};
#ifndef OPENSSL_NO_ECDSA
static unsigned char suiteb_sigalgs[] = {
tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
};
#endif
size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
{
/* If Suite B mode use Suite B sigalgs only, ignore any other
* preferences.
*/
#ifndef OPENSSL_NO_EC
switch (tls1_suiteb(s))
{
case SSL_CERT_FLAG_SUITEB_128_LOS:
*psigs = suiteb_sigalgs;
return sizeof(suiteb_sigalgs);
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*psigs = suiteb_sigalgs;
return 2;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*psigs = suiteb_sigalgs + 2;
return 2;
}
#endif
/* If server use client authentication sigalgs if not NULL */
if (s->server && s->cert->client_sigalgs)
{
*psigs = s->cert->client_sigalgs;
return s->cert->client_sigalgslen;
}
else if (s->cert->conf_sigalgs)
{
*psigs = s->cert->conf_sigalgs;
return s->cert->conf_sigalgslen;
}
else
{
*psigs = tls12_sigalgs;
return sizeof(tls12_sigalgs);
}
}
/* tls12_check_peer_sigalg parses a SignatureAndHashAlgorithm out of
* |cbs|. It checks it is consistent with |s|'s sent supported
* signature algorithms and, if so, writes the relevant digest into
* |*out_md| and returns 1. Otherwise it returns 0 and writes an alert
* into |*out_alert|.
*/
int tls12_check_peer_sigalg(const EVP_MD **out_md, int *out_alert,
SSL *s, CBS *cbs, EVP_PKEY *pkey)
{
const unsigned char *sent_sigs;
size_t sent_sigslen, i;
int sigalg = tls12_get_sigid(pkey);
uint8_t hash, signature;
/* Should never happen */
if (sigalg == -1)
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, ERR_R_INTERNAL_ERROR);
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
if (!CBS_get_u8(cbs, &hash) ||
!CBS_get_u8(cbs, &signature))
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_DECODE_ERROR);
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* Check key type is consistent with signature */
if (sigalg != signature)
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
#ifndef OPENSSL_NO_EC
if (pkey->type == EVP_PKEY_EC)
{
uint16_t curve_id;
uint8_t comp_id;
/* Check compression and curve matches extensions */
if (!tls1_curve_params_from_ec_key(&curve_id, &comp_id, pkey->pkey.ec))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
if (!s->server && !tls1_check_ec_key(s, &curve_id, &comp_id))
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_CURVE);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
/* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
if (tls1_suiteb(s))
{
if (curve_id == TLSEXT_curve_P_256)
{
if (hash != TLSEXT_hash_sha256)
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_ILLEGAL_SUITEB_DIGEST);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
else if (curve_id == TLSEXT_curve_P_384)
{
if (hash != TLSEXT_hash_sha384)
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_ILLEGAL_SUITEB_DIGEST);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
else
{
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
}
else if (tls1_suiteb(s))
{
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
#endif
/* Check signature matches a type we sent */
sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
for (i = 0; i < sent_sigslen; i+=2, sent_sigs+=2)
{
if (hash == sent_sigs[0] && signature == sent_sigs[1])
break;
}
/* Allow fallback to SHA1 if not strict mode */
if (i == sent_sigslen && (hash != TLSEXT_hash_sha1 || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_WRONG_SIGNATURE_TYPE);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
*out_md = tls12_get_hash(hash);
if (*out_md == NULL)
{
OPENSSL_PUT_ERROR(SSL, tls12_check_peer_sigalg, SSL_R_UNKNOWN_DIGEST);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
/* Store the digest used so applications can retrieve it if they
* wish.
*/
if (s->session && s->session->sess_cert)
s->session->sess_cert->peer_key->digest = *out_md;
return 1;
}
/* Get a mask of disabled algorithms: an algorithm is disabled
* if it isn't supported or doesn't appear in supported signature
* algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
* session and not global settings.
*
*/
void ssl_set_client_disabled(SSL *s)
{
CERT *c = s->cert;
const unsigned char *sigalgs;
size_t i, sigalgslen;
int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
c->mask_a = 0;
c->mask_k = 0;
/* Don't allow TLS 1.2 only ciphers if we don't suppport them */
if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s))
c->mask_ssl = SSL_TLSV1_2;
else
c->mask_ssl = 0;
/* Now go through all signature algorithms seeing if we support
* any for RSA, DSA, ECDSA. Do this for all versions not just
* TLS 1.2.
*/
sigalgslen = tls12_get_psigalgs(s, &sigalgs);
for (i = 0; i < sigalgslen; i += 2, sigalgs += 2)
{
switch(sigalgs[1])
{
case TLSEXT_signature_rsa:
have_rsa = 1;
break;
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
have_dsa = 1;
break;
#endif
#ifndef OPENSSL_NO_ECDSA
case TLSEXT_signature_ecdsa:
have_ecdsa = 1;
break;
#endif
}
}
/* Disable auth and static DH if we don't include any appropriate
* signature algorithms.
*/
if (!have_rsa)
{
c->mask_a |= SSL_aRSA;
c->mask_k |= SSL_kDHr|SSL_kECDHr;
}
if (!have_dsa)
{
c->mask_a |= SSL_aDSS;
c->mask_k |= SSL_kDHd;
}
if (!have_ecdsa)
{
c->mask_a |= SSL_aECDSA;
c->mask_k |= SSL_kECDHe;
}
/* with PSK there must be client callback set */
if (!s->psk_client_callback)
{
c->mask_a |= SSL_aPSK;
c->mask_k |= SSL_kPSK;
}
c->valid = 1;
}
/* header_len is the length of the ClientHello header written so far, used to
* compute padding. It does not include the record header. Pass 0 if no padding
* is to be done. */
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, size_t header_len)
{
int extdatalen=0;
unsigned char *ret = buf;
unsigned char *orig = buf;
#ifndef OPENSSL_NO_EC
/* See if we support any ECC ciphersuites */
int using_ecc = 0;
if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s))
{
int i;
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;
}
}
}
#endif
/* 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))
{
OPENSSL_PUT_ERROR(SSL, 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))
{
OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
{
int ticklen;
if (!s->new_session && s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
else if (s->session && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data)
{
s->session->tlsext_tick = BUF_memdup(
s->tlsext_session_ticket->data,
s->tlsext_session_ticket->length);
if (!s->session->tlsext_tick)
return NULL;
ticklen = s->tlsext_session_ticket->length;
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 (SSL_USE_SIGALGS(s))
{
size_t salglen;
const unsigned char *salg;
salglen = tls12_get_psigalgs(s, &salg);
if ((size_t)(limit - ret) < salglen + 6)
return NULL;
s2n(TLSEXT_TYPE_signature_algorithms,ret);
s2n(salglen + 2, ret);
s2n(salglen, ret);
memcpy(ret, salg, salglen);
ret += salglen;
}
/* TODO(fork): we probably want OCSP stapling, but it currently pulls in a lot of code. */
#if 0
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
{
int i;
long extlen, idlen, itmp;
OCSP_RESPID *id;
idlen = 0;
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
{
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
itmp = i2d_OCSP_RESPID(id, NULL);
if (itmp <= 0)
return NULL;
idlen += itmp + 2;
}
if (s->tlsext_ocsp_exts)
{
extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
if (extlen < 0)
return NULL;
}
else
extlen = 0;
if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
if (extlen + idlen > 0xFFF0)
return NULL;
s2n(extlen + idlen + 5, ret);
*(ret++) = TLSEXT_STATUSTYPE_ocsp;
s2n(idlen, ret);
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
{
/* save position of id len */
unsigned char *q = ret;
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
/* skip over id len */
ret += 2;
itmp = i2d_OCSP_RESPID(id, &ret);
/* write id len */
s2n(itmp, q);
}
s2n(extlen, ret);
if (extlen > 0)
i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
}
#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
if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len)
{
if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
s2n(2 + s->alpn_client_proto_list_len,ret);
s2n(s->alpn_client_proto_list_len,ret);
memcpy(ret, s->alpn_client_proto_list,
s->alpn_client_proto_list_len);
ret += s->alpn_client_proto_list_len;
}
if (s->tlsext_channel_id_enabled)
{
/* The client advertises an emtpy extension to indicate its
* support for Channel ID. */
if (limit - ret - 4 < 0)
return NULL;
if (s->ctx->tlsext_channel_id_enabled_new)
s2n(TLSEXT_TYPE_channel_id_new,ret);
else
s2n(TLSEXT_TYPE_channel_id,ret);
s2n(0,ret);
}
if(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))
{
OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#ifndef OPENSSL_NO_EC
if (using_ecc)
{
/* Add TLS extension ECPointFormats to the ClientHello message */
long lenmax;
const uint8_t *formats;
const uint16_t *curves;
size_t formats_len, curves_len, i;
tls1_get_formatlist(s, &formats, &formats_len);
if ((lenmax = limit - ret - 5) < 0) return NULL;
if (formats_len > (size_t)lenmax) return NULL;
if (formats_len > 255)
{
OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats,ret);
s2n(formats_len + 1,ret);
*(ret++) = (unsigned char)formats_len;
memcpy(ret, formats, formats_len);
ret+=formats_len;
/* Add TLS extension EllipticCurves to the ClientHello message */
tls1_get_curvelist(s, 0, &curves, &curves_len);
if ((lenmax = limit - ret - 6) < 0) return NULL;
if ((curves_len * 2) > (size_t)lenmax) return NULL;
if ((curves_len * 2) > 65532)
{
OPENSSL_PUT_ERROR(SSL, ssl_add_clienthello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_elliptic_curves,ret);
s2n((curves_len * 2) + 2, ret);
/* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
* elliptic_curve_list, but the examples use two bytes.
* http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
* resolves this to two bytes.
*/
s2n(curves_len * 2, ret);
for (i = 0; i < curves_len; i++)
{
s2n(curves[i], ret);
}
}
#endif /* OPENSSL_NO_EC */
#ifdef TLSEXT_TYPE_padding
/* 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 (header_len > 0)
{
header_len += ret - orig;
if (header_len > 0xff && header_len < 0x200)
{
size_t padding_len = 0x200 - header_len;
/* Extensions take at least four bytes to encode. Always
* include least one byte of data if including the
* extension. WebSphere Application Server 7.0 is
* intolerant to the last extension being zero-length. */
if (padding_len >= 4 + 1)
padding_len -= 4;
else
padding_len = 1;
if (limit - ret - 4 - (long)padding_len < 0)
return NULL;
s2n(TLSEXT_TYPE_padding, ret);
s2n(padding_len, ret);
memset(ret, 0, padding_len);
ret += padding_len;
}
}
#endif
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
#ifndef OPENSSL_NO_EC
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);
#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))
{
OPENSSL_PUT_ERROR(SSL, 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))
{
OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#ifndef OPENSSL_NO_EC
if (using_ecc)
{
const unsigned char *plist;
size_t plistlen;
/* Add TLS extension ECPointFormats to the ServerHello message */
long lenmax;
tls1_get_formatlist(s, &plist, &plistlen);
if ((lenmax = limit - ret - 5) < 0) return NULL;
if (plistlen > (size_t)lenmax) return NULL;
if (plistlen > 255)
{
OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats,ret);
s2n(plistlen + 1,ret);
*(ret++) = (unsigned char) plistlen;
memcpy(ret, plist, plistlen);
ret+=plistlen;
}
/* 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);
}
if(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))
{
OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret+=el;
}
#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 (s->s3->alpn_selected)
{
const uint8_t *selected = s->s3->alpn_selected;
size_t len = s->s3->alpn_selected_len;
if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
s2n(3 + len,ret);
s2n(1 + len,ret);
*ret++ = len;
memcpy(ret, selected, len);
ret += len;
}
/* If the client advertised support for Channel ID, and we have it
* enabled, then we want to echo it back. */
if (s->s3->tlsext_channel_id_valid)
{
if (limit - ret - 4 < 0)
return NULL;
if (s->s3->tlsext_channel_id_new)
s2n(TLSEXT_TYPE_channel_id_new,ret);
else
s2n(TLSEXT_TYPE_channel_id,ret);
s2n(0,ret);
}
if ((extdatalen = ret-orig-2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
/* tls1_alpn_handle_client_hello is called to process the ALPN extension in a
* ClientHello.
* cbs: the contents of the extension, not including the type and length.
* out_alert: a pointer to the alert value to send in the event of a zero
* return.
*
* returns: 1 on success. */
static int tls1_alpn_handle_client_hello(SSL *s, CBS *cbs, int *out_alert)
{
CBS protocol_name_list;
const unsigned char *selected;
unsigned char selected_len;
int r;
if (s->ctx->alpn_select_cb == NULL)
return 1;
if (!CBS_get_u16_length_prefixed(cbs, &protocol_name_list) ||
CBS_len(cbs) != 0 ||
CBS_len(&protocol_name_list) < 2)
goto parse_error;
/* Validate the protocol list. */
CBS protocol_name_list_copy = protocol_name_list;
while (CBS_len(&protocol_name_list_copy) > 0)
{
CBS protocol_name;
if (!CBS_get_u8_length_prefixed(&protocol_name_list_copy, &protocol_name))
goto parse_error;
}
r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
CBS_data(&protocol_name_list), CBS_len(&protocol_name_list),
s->ctx->alpn_select_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
if (s->s3->alpn_selected)
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = BUF_memdup(selected, selected_len);
if (!s->s3->alpn_selected)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->s3->alpn_selected_len = selected_len;
}
return 1;
parse_error:
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
static int ssl_scan_clienthello_tlsext(SSL *s, CBS *cbs, int *out_alert)
{
int renegotiate_seen = 0;
CBS extensions;
size_t i;
s->servername_done = 0;
s->tlsext_status_type = -1;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
if (s->s3->alpn_selected)
{
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
}
/* Clear any signature algorithms extension received */
if (s->cert->peer_sigalgs)
{
OPENSSL_free(s->cert->peer_sigalgs);
s->cert->peer_sigalgs = NULL;
}
/* Clear any shared sigtnature algorithms */
if (s->cert->shared_sigalgs)
{
OPENSSL_free(s->cert->shared_sigalgs);
s->cert->shared_sigalgs = NULL;
}
/* Clear certificate digests and validity flags */
for (i = 0; i < SSL_PKEY_NUM; i++)
{
s->cert->pkeys[i].digest = NULL;
s->cert->pkeys[i].valid_flags = 0;
}
/* TODO(fork): we probably want OCSP stapling support, but this pulls in
* a lot of code. */
#if 0
/* Clear OCSP state. */
s->tlsext_status_type = -1;
if (s->tlsext_ocsp_ids)
{
sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids, OCSP_RESPID_free);
s->tlsext_ocsp_ids = NULL;
}
if (s->tlsext_ocsp_exts)
{
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts, X509_EXTENSION_free);
s->tlsext_ocsp_exts = NULL;
}
#endif
/* There may be no extensions. */
if (CBS_len(cbs) == 0)
{
goto ri_check;
}
/* Decode the extensions block and check it is valid. */
if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
!tls1_check_duplicate_extensions(&extensions))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
while (CBS_len(&extensions) != 0)
{
uint16_t type;
CBS extension;
/* Decode the next extension. */
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->tlsext_debug_cb)
{
s->tlsext_debug_cb(s, 0, type, (unsigned char*)CBS_data(&extension),
CBS_len(&extension), 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)
{
CBS server_name_list;
if (!CBS_get_u16_length_prefixed(&extension, &server_name_list) ||
CBS_len(&server_name_list) < 1 ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* Decode each ServerName in the extension. */
while (CBS_len(&server_name_list) > 0)
{
uint8_t name_type;
CBS host_name;
/* Decode the NameType. */
if (!CBS_get_u8(&server_name_list, &name_type))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* Only host_name is supported. */
if (name_type != TLSEXT_NAMETYPE_host_name)
continue;
if (!s->hit)
{
if (s->session->tlsext_hostname)
{
/* The ServerNameList MUST NOT
contain more than one name of
the same name_type. */
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!CBS_get_u16_length_prefixed(&server_name_list, &host_name) ||
CBS_len(&host_name) < 1)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (CBS_len(&host_name) > TLSEXT_MAXLEN_host_name ||
CBS_contains_zero_byte(&host_name))
{
*out_alert = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
/* Copy the hostname as a string. */
if (!CBS_strdup(&host_name, &s->session->tlsext_hostname))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->servername_done = 1;
}
else
{
s->servername_done = s->session->tlsext_hostname
&& strlen(s->session->tlsext_hostname) == CBS_len(&host_name)
&& strncmp(s->session->tlsext_hostname,
(char *)CBS_data(&host_name), CBS_len(&host_name)) == 0;
}
}
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats)
{
CBS ec_point_format_list;
if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit)
{
if (!CBS_stow(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
}
else if (type == TLSEXT_TYPE_elliptic_curves)
{
CBS elliptic_curve_list;
size_t i, num_curves;
if (!CBS_get_u16_length_prefixed(&extension, &elliptic_curve_list) ||
CBS_len(&elliptic_curve_list) == 0 ||
(CBS_len(&elliptic_curve_list) & 1) != 0 ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit)
{
if (s->session->tlsext_ellipticcurvelist)
{
OPENSSL_free(s->session->tlsext_ellipticcurvelist);
s->session->tlsext_ellipticcurvelist_length = 0;
}
s->session->tlsext_ellipticcurvelist =
(uint16_t*)OPENSSL_malloc(CBS_len(&elliptic_curve_list));
if (s->session->tlsext_ellipticcurvelist == NULL)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
num_curves = CBS_len(&elliptic_curve_list) / 2;
for (i = 0; i < num_curves; i++)
{
if (!CBS_get_u16(&elliptic_curve_list,
&s->session->tlsext_ellipticcurvelist[i]))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
if (CBS_len(&elliptic_curve_list) != 0)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ellipticcurvelist_length = num_curves;
}
}
#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, CBS_data(&extension), CBS_len(&extension), s->tls_session_ticket_ext_cb_arg))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if (!ssl_parse_clienthello_renegotiate_ext(s, &extension, out_alert))
return 0;
renegotiate_seen = 1;
}
else if (type == TLSEXT_TYPE_signature_algorithms)
{
CBS supported_signature_algorithms;
if (!CBS_get_u16_length_prefixed(&extension, &supported_signature_algorithms) ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* Ensure the signature algorithms are non-empty. It
* contains a list of SignatureAndHashAlgorithms
* which are two bytes each. */
if (CBS_len(&supported_signature_algorithms) == 0 ||
(CBS_len(&supported_signature_algorithms) % 2) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!tls1_process_sigalgs(s, &supported_signature_algorithms))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* If sigalgs received and no shared algorithms fatal
* error.
*/
if (s->cert->peer_sigalgs && !s->cert->shared_sigalgs)
{
OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
*out_alert = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
/* TODO(fork): we probably want OCSP stapling support, but this pulls in a lot of code. */
#if 0
else if (type == TLSEXT_TYPE_status_request)
{
uint8_t status_type;
CBS responder_id_list;
CBS request_extensions;
if (!CBS_get_u8(&extension, &status_type))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* Only OCSP is supported. */
if (status_type != TLSEXT_STATUSTYPE_ocsp)
continue;
s->tlsext_status_type = status_type;
/* Extension consists of a responder_id_list and
* request_extensions. */
if (!CBS_get_u16_length_prefixed(&extension, &responder_id_list) ||
!CBS_get_u16_length_prefixed(&extension, &request_extensions) ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (CBS_len(&responder_id_list) > 0)
{
s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
if (s->tlsext_ocsp_ids == NULL)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Parse out the responder IDs. */
while (CBS_len(&responder_id_list) > 0)
{
CBS responder_id;
OCSP_RESPID *id;
const uint8_t *data;
/* Each ResponderID must have size at least 1. */
if (!CBS_get_u16_length_prefixed(&responder_id_list, &responder_id) ||
CBS_len(&responder_id) < 1)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* TODO(fork): Add CBS versions of d2i_FOO_BAR. */
data = CBS_data(&responder_id);
id = d2i_OCSP_RESPID(NULL, &data, CBS_len(&responder_id));
if (!id)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!CBS_skip(&responder_id, data - CBS_data(&responder_id)))
{
/* This should never happen. */
*out_alert = SSL_AD_INTERNAL_ERROR;
OCSP_RESPID_free(id);
return 0;
}
if (CBS_len(&responder_id) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
OCSP_RESPID_free(id);
return 0;
}
if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
OCSP_RESPID_free(id);
return 0;
}
}
/* Parse out request_extensions. */
if (CBS_len(&request_extensions) > 0)
{
const uint8_t *data;
data = CBS_data(&request_extensions);
s->tlsext_ocsp_exts = d2i_X509_EXTENSIONS(NULL,
&data, CBS_len(&request_extensions));
if (s->tlsext_ocsp_exts == NULL)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!CBS_skip(&request_extensions, data - CBS_data(&request_extensions)))
{
/* This should never happen. */
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
if (CBS_len(&request_extensions) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0 &&
s->s3->alpn_selected == NULL)
{
/* The extension must be empty. */
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 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
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
s->ctx->alpn_select_cb &&
s->s3->tmp.finish_md_len == 0)
{
if (!tls1_alpn_handle_client_hello(s, &extension, out_alert))
return 0;
#ifndef OPENSSL_NO_NEXTPROTONEG
/* ALPN takes precedence over NPN. */
s->s3->next_proto_neg_seen = 0;
#endif
}
else if (type == TLSEXT_TYPE_channel_id &&
s->tlsext_channel_id_enabled)
{
/* The extension must be empty. */
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->tlsext_channel_id_valid = 1;
}
else if (type == TLSEXT_TYPE_channel_id_new &&
s->tlsext_channel_id_enabled)
{
/* The extension must be empty. */
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->tlsext_channel_id_valid = 1;
s->s3->tlsext_channel_id_new = 1;
}
/* session ticket processed earlier */
else if (type == TLSEXT_TYPE_use_srtp)
{
if (!ssl_parse_clienthello_use_srtp_ext(s, &extension, out_alert))
return 0;
}
}
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->renegotiate &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
*out_alert = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl_add_serverhello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
/* If no signature algorithms extension set default values */
if (!s->cert->peer_sigalgs)
ssl_cert_set_default_md(s->cert);
return 1;
}
int ssl_parse_clienthello_tlsext(SSL *s, CBS *cbs)
{
int alert = -1;
if (ssl_scan_clienthello_tlsext(s, cbs, &alert) <= 0)
{
ssl3_send_alert(s, SSL3_AL_FATAL, alert);
return 0;
}
if (ssl_check_clienthello_tlsext_early(s) <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl_parse_clienthello_tlsext, SSL_R_CLIENTHELLO_TLSEXT);
return 0;
}
return 1;
}
#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(const CBS *cbs)
{
CBS copy = *cbs;
while (CBS_len(&copy) != 0)
{
CBS proto;
if (!CBS_get_u8_length_prefixed(&copy, &proto) ||
CBS_len(&proto) == 0)
{
return 0;
}
}
return 1;
}
#endif
static int ssl_scan_serverhello_tlsext(SSL *s, CBS *cbs, int *out_alert)
{
int tlsext_servername = 0;
int renegotiate_seen = 0;
CBS extensions;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
s->tlsext_ticket_expected = 0;
if (s->s3->alpn_selected)
{
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
}
/* There may be no extensions. */
if (CBS_len(cbs) == 0)
{
goto ri_check;
}
/* Decode the extensions block and check it is valid. */
if (!CBS_get_u16_length_prefixed(cbs, &extensions) ||
!tls1_check_duplicate_extensions(&extensions))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
while (CBS_len(&extensions) != 0)
{
uint16_t type;
CBS extension;
/* Decode the next extension. */
if (!CBS_get_u16(&extensions, &type) ||
!CBS_get_u16_length_prefixed(&extensions, &extension))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->tlsext_debug_cb)
{
s->tlsext_debug_cb(s, 1, type, (unsigned char*)CBS_data(&extension),
CBS_len(&extension), s->tlsext_debug_arg);
}
if (type == TLSEXT_TYPE_server_name)
{
/* The extension must be empty. */
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
/* We must have sent it in ClientHello. */
if (s->tlsext_hostname == NULL)
{
*out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
return 0;
}
tlsext_servername = 1;
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats)
{
CBS ec_point_format_list;
if (!CBS_get_u8_length_prefixed(&extension, &ec_point_format_list) ||
CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit)
{
if (!CBS_stow(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
}
#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, CBS_data(&extension), CBS_len(&extension),
s->tls_session_ticket_ext_cb_arg))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
if ((SSL_get_options(s) & SSL_OP_NO_TICKET) || CBS_len(&extension) > 0)
{
*out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
else if (type == TLSEXT_TYPE_status_request)
{
/* The extension MUST be empty and may only sent if
* we've requested a status request message. */
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->tlsext_status_type == -1)
{
*out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set a flag to expect a 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)
{
*out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The data must be valid. */
if (!ssl_next_proto_validate(&extension))
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (s->ctx->next_proto_select_cb(s, &selected, &selected_len,
CBS_data(&extension), CBS_len(&extension),
s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->next_proto_negotiated = BUF_memdup(selected, selected_len);
if (s->next_proto_negotiated == NULL)
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
s->next_proto_negotiated_len = selected_len;
s->s3->next_proto_neg_seen = 1;
}
#endif
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation)
{
CBS protocol_name_list, protocol_name;
/* We must have requested it. */
if (s->alpn_client_proto_list == NULL)
{
*out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The extension data consists of a ProtocolNameList
* which must have exactly one ProtocolName. Each of
* these is length-prefixed. */
if (!CBS_get_u16_length_prefixed(&extension, &protocol_name_list) ||
CBS_len(&extension) != 0 ||
!CBS_get_u8_length_prefixed(&protocol_name_list, &protocol_name) ||
CBS_len(&protocol_name_list) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
if (!CBS_stow(&protocol_name,
&s->s3->alpn_selected,
&s->s3->alpn_selected_len))
{
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
else if (type == TLSEXT_TYPE_channel_id)
{
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->tlsext_channel_id_valid = 1;
}
else if (type == TLSEXT_TYPE_channel_id_new)
{
if (CBS_len(&extension) != 0)
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
s->s3->tlsext_channel_id_valid = 1;
s->s3->tlsext_channel_id_new = 1;
}
else if (type == TLSEXT_TYPE_renegotiate)
{
if (!ssl_parse_serverhello_renegotiate_ext(s, &extension, out_alert))
return 0;
renegotiate_seen = 1;
}
else if (type == TLSEXT_TYPE_use_srtp)
{
if (!ssl_parse_serverhello_use_srtp_ext(s, &extension, out_alert))
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)
{
*out_alert = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
}
else
{
*out_alert = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
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))
{
*out_alert = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl_scan_serverhello_tlsext, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
return 1;
}
int ssl_prepare_clienthello_tlsext(SSL *s)
{
return 1;
}
int ssl_prepare_serverhello_tlsext(SSL *s)
{
return 1;
}
static 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);
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)
{
OPENSSL_PUT_ERROR(SSL, ssl_add_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);
/* 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;
}
}
int ssl_parse_serverhello_tlsext(SSL *s, CBS *cbs)
{
int alert = -1;
if (s->version < SSL3_VERSION)
return 1;
if (ssl_scan_serverhello_tlsext(s, cbs, &alert) <= 0)
{
ssl3_send_alert(s, SSL3_AL_FATAL, alert);
return 0;
}
if (ssl_check_serverhello_tlsext(s) <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl_parse_serverhello_tlsext, SSL_R_SERVERHELLO_TLSEXT);
return 0;
}
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.
*
* ctx: contains the early callback context, which is the result of a
* shallow parse of 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, const struct ssl_early_callback_ctx *ctx,
SSL_SESSION **ret)
{
*ret = NULL;
s->tlsext_ticket_expected = 0;
const unsigned char *data;
size_t len;
int r;
/* 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) && !ctx->extensions)
return 0;
if (!SSL_early_callback_ctx_extension_get(
ctx, TLSEXT_TYPE_session_ticket, &data, &len))
{
return 0;
}
if (len == 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, data, len, ctx->session_id,
ctx->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;
}
}
/* 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))
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_ex(&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[] = {
{NID_md5, TLSEXT_hash_md5},
{NID_sha1, TLSEXT_hash_sha1},
{NID_sha224, TLSEXT_hash_sha224},
{NID_sha256, TLSEXT_hash_sha256},
{NID_sha384, TLSEXT_hash_sha384},
{NID_sha512, TLSEXT_hash_sha512}
};
static tls12_lookup tls12_sig[] = {
{EVP_PKEY_RSA, TLSEXT_signature_rsa},
{EVP_PKEY_DSA, TLSEXT_signature_dsa},
{EVP_PKEY_EC, TLSEXT_signature_ecdsa}
};
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;
}
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 NID_undef;
}
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_MD5
case TLSEXT_hash_md5:
return EVP_md5();
#endif
#ifndef OPENSSL_NO_SHA
case TLSEXT_hash_sha1:
return EVP_sha1();
#endif
case TLSEXT_hash_sha224:
return EVP_sha224();
case TLSEXT_hash_sha256:
return EVP_sha256();
case TLSEXT_hash_sha384:
return EVP_sha384();
case TLSEXT_hash_sha512:
return EVP_sha512();
default:
return NULL;
}
}
static int tls12_get_pkey_idx(unsigned char sig_alg)
{
switch(sig_alg)
{
case TLSEXT_signature_rsa:
return SSL_PKEY_RSA_SIGN;
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
return SSL_PKEY_DSA_SIGN;
#endif
#ifndef OPENSSL_NO_ECDSA
case TLSEXT_signature_ecdsa:
return SSL_PKEY_ECC;
#endif
}
return -1;
}
/* Convert TLS 1.2 signature algorithm extension values into NIDs */
static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
int *psignhash_nid, const unsigned char *data)
{
int sign_nid = 0, hash_nid = 0;
if (!phash_nid && !psign_nid && !psignhash_nid)
return;
if (phash_nid || psignhash_nid)
{
hash_nid = tls12_find_nid(data[0], tls12_md,
sizeof(tls12_md)/sizeof(tls12_lookup));
if (phash_nid)
*phash_nid = hash_nid;
}
if (psign_nid || psignhash_nid)
{
sign_nid = tls12_find_nid(data[1], tls12_sig,
sizeof(tls12_sig)/sizeof(tls12_lookup));
if (psign_nid)
*psign_nid = sign_nid;
}
if (psignhash_nid)
{
if (sign_nid && hash_nid)
OBJ_find_sigid_by_algs(psignhash_nid,
hash_nid, sign_nid);
else
*psignhash_nid = NID_undef;
}
}
/* Given preference and allowed sigalgs set shared sigalgs */
static int tls12_do_shared_sigalgs(TLS_SIGALGS *shsig,
const unsigned char *pref, size_t preflen,
const unsigned char *allow, size_t allowlen)
{
const unsigned char *ptmp, *atmp;
size_t i, j, nmatch = 0;
for (i = 0, ptmp = pref; i < preflen; i+=2, ptmp+=2)
{
/* Skip disabled hashes or signature algorithms */
if (tls12_get_hash(ptmp[0]) == NULL)
continue;
if (tls12_get_pkey_idx(ptmp[1]) == -1)
continue;
for (j = 0, atmp = allow; j < allowlen; j+=2, atmp+=2)
{
if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1])
{
nmatch++;
if (shsig)
{
shsig->rhash = ptmp[0];
shsig->rsign = ptmp[1];
tls1_lookup_sigalg(&shsig->hash_nid,
&shsig->sign_nid,
&shsig->signandhash_nid,
ptmp);
shsig++;
}
break;
}
}
}
return nmatch;
}
/* Set shared signature algorithms for SSL structures */
static int tls1_set_shared_sigalgs(SSL *s)
{
const unsigned char *pref, *allow, *conf;
size_t preflen, allowlen, conflen;
size_t nmatch;
TLS_SIGALGS *salgs = NULL;
CERT *c = s->cert;
unsigned int is_suiteb = tls1_suiteb(s);
if (c->shared_sigalgs)
{
OPENSSL_free(c->shared_sigalgs);
c->shared_sigalgs = NULL;
}
/* If client use client signature algorithms if not NULL */
if (!s->server && c->client_sigalgs && !is_suiteb)
{
conf = c->client_sigalgs;
conflen = c->client_sigalgslen;
}
else if (c->conf_sigalgs && !is_suiteb)
{
conf = c->conf_sigalgs;
conflen = c->conf_sigalgslen;
}
else
conflen = tls12_get_psigalgs(s, &conf);
if(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb)
{
pref = conf;
preflen = conflen;
allow = c->peer_sigalgs;
allowlen = c->peer_sigalgslen;
}
else
{
allow = conf;
allowlen = conflen;
pref = c->peer_sigalgs;
preflen = c->peer_sigalgslen;
}
nmatch = tls12_do_shared_sigalgs(NULL, pref, preflen, allow, allowlen);
if (!nmatch)
return 1;
salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
if (!salgs)
return 0;
nmatch = tls12_do_shared_sigalgs(salgs, pref, preflen, allow, allowlen);
c->shared_sigalgs = salgs;
c->shared_sigalgslen = nmatch;
return 1;
}
/* Set preferred digest for each key type */
int tls1_process_sigalgs(SSL *s, const CBS *sigalgs)
{
int idx;
size_t i;
const EVP_MD *md;
CERT *c = s->cert;
TLS_SIGALGS *sigptr;
/* Extension ignored for inappropriate versions */
if (!SSL_USE_SIGALGS(s))
return 1;
/* Length must be even */
if (CBS_len(sigalgs) % 2 != 0)
return 0;
/* Should never happen */
if (!c)
return 0;
if (!CBS_stow(sigalgs, &c->peer_sigalgs, &c->peer_sigalgslen))
return 0;
tls1_set_shared_sigalgs(s);
#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
{
/* Use first set signature preference to force message
* digest, ignoring any peer preferences.
*/
const unsigned char *sigs = NULL;
if (s->server)
sigs = c->conf_sigalgs;
else
sigs = c->client_sigalgs;
if (sigs)
{
idx = tls12_get_pkey_idx(sigs[1]);
md = tls12_get_hash(sigs[0]);
c->pkeys[idx].digest = md;
c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
if (idx == SSL_PKEY_RSA_SIGN)
{
c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
}
}
}
#endif
for (i = 0, sigptr = c->shared_sigalgs;
i < c->shared_sigalgslen; i++, sigptr++)
{
idx = tls12_get_pkey_idx(sigptr->rsign);
if (idx > 0 && c->pkeys[idx].digest == NULL)
{
md = tls12_get_hash(sigptr->rhash);
c->pkeys[idx].digest = md;
c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
if (idx == SSL_PKEY_RSA_SIGN)
{
c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
}
}
}
/* In strict mode leave unset digests as NULL to indicate we can't
* use the certificate for signing.
*/
if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
{
/* 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
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();
}
#ifndef OPENSSL_NO_ECDSA
if (!c->pkeys[SSL_PKEY_ECC].digest)
c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
#endif
}
return 1;
}
int SSL_get_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
const unsigned char *psig = s->cert->peer_sigalgs;
if (psig == NULL)
return 0;
if (idx >= 0)
{
idx <<= 1;
if (idx >= (int)s->cert->peer_sigalgslen)
return 0;
psig += idx;
if (rhash)
*rhash = psig[0];
if (rsig)
*rsig = psig[1];
tls1_lookup_sigalg(phash, psign, psignhash, psig);
}
return s->cert->peer_sigalgslen / 2;
}
int SSL_get_shared_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs;
if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen)
return 0;
shsigalgs += idx;
if (phash)
*phash = shsigalgs->hash_nid;
if (psign)
*psign = shsigalgs->sign_nid;
if (psignhash)
*psignhash = shsigalgs->signandhash_nid;
if (rsig)
*rsig = shsigalgs->rsign;
if (rhash)
*rhash = shsigalgs->rhash;
return s->cert->shared_sigalgslen;
}
/* tls1_channel_id_hash calculates the signed data for a Channel ID on the given
* SSL connection and writes it to |md|. */
int
tls1_channel_id_hash(EVP_MD_CTX *md, SSL *s)
{
EVP_MD_CTX ctx;
unsigned char temp_digest[EVP_MAX_MD_SIZE];
unsigned temp_digest_len;
int i;
static const char kClientIDMagic[] = "TLS Channel ID signature";
if (s->s3->handshake_buffer)
if (!ssl3_digest_cached_records(s))
return 0;
EVP_DigestUpdate(md, kClientIDMagic, sizeof(kClientIDMagic));
if (s->hit && s->s3->tlsext_channel_id_new)
{
static const char kResumptionMagic[] = "Resumption";
EVP_DigestUpdate(md, kResumptionMagic,
sizeof(kResumptionMagic));
if (s->session->original_handshake_hash_len == 0)
return 0;
EVP_DigestUpdate(md, s->session->original_handshake_hash,
s->session->original_handshake_hash_len);
}
EVP_MD_CTX_init(&ctx);
for (i = 0; i < SSL_MAX_DIGEST; i++)
{
if (s->s3->handshake_dgst[i] == NULL)
continue;
EVP_MD_CTX_copy_ex(&ctx, s->s3->handshake_dgst[i]);
EVP_DigestFinal_ex(&ctx, temp_digest, &temp_digest_len);
EVP_DigestUpdate(md, temp_digest, temp_digest_len);
}
EVP_MD_CTX_cleanup(&ctx);
return 1;
}
/* tls1_record_handshake_hashes_for_channel_id records the current handshake
* hashes in |s->session| so that Channel ID resumptions can sign that data. */
int tls1_record_handshake_hashes_for_channel_id(SSL *s)
{
int digest_len;
/* This function should never be called for a resumed session because
* the handshake hashes that we wish to record are for the original,
* full handshake. */
if (s->hit)
return -1;
/* It only makes sense to call this function if Channel IDs have been
* negotiated. */
if (!s->s3->tlsext_channel_id_new)
return -1;
digest_len = tls1_handshake_digest(
s, s->session->original_handshake_hash,
sizeof(s->session->original_handshake_hash));
if (digest_len < 0)
return -1;
s->session->original_handshake_hash_len = digest_len;
return 1;
}
/* TODO(fork): remove */
#if 0
#define MAX_SIGALGLEN (TLSEXT_hash_num * TLSEXT_signature_num * 2)
typedef struct
{
size_t sigalgcnt;
int sigalgs[MAX_SIGALGLEN];
} sig_cb_st;
static int sig_cb(const char *elem, int len, void *arg)
{
sig_cb_st *sarg = arg;
size_t i;
char etmp[20], *p;
int sig_alg, hash_alg;
if (sarg->sigalgcnt == MAX_SIGALGLEN)
return 0;
if (len > (int)(sizeof(etmp) - 1))
return 0;
memcpy(etmp, elem, len);
etmp[len] = 0;
p = strchr(etmp, '+');
if (!p)
return 0;
*p = 0;
p++;
if (!*p)
return 0;
if (!strcmp(etmp, "RSA"))
sig_alg = EVP_PKEY_RSA;
else if (!strcmp(etmp, "DSA"))
sig_alg = EVP_PKEY_DSA;
else if (!strcmp(etmp, "ECDSA"))
sig_alg = EVP_PKEY_EC;
else return 0;
hash_alg = OBJ_sn2nid(p);
if (hash_alg == NID_undef)
hash_alg = OBJ_ln2nid(p);
if (hash_alg == NID_undef)
return 0;
for (i = 0; i < sarg->sigalgcnt; i+=2)
{
if (sarg->sigalgs[i] == sig_alg
&& sarg->sigalgs[i + 1] == hash_alg)
return 0;
}
sarg->sigalgs[sarg->sigalgcnt++] = hash_alg;
sarg->sigalgs[sarg->sigalgcnt++] = sig_alg;
return 1;
}
/* Set suppored signature algorithms based on a colon separated list
* of the form sig+hash e.g. RSA+SHA512:DSA+SHA512 */
int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
{
sig_cb_st sig;
sig.sigalgcnt = 0;
if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
return 0;
if (c == NULL)
return 1;
return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
}
#endif
int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)
{
unsigned char *sigalgs, *sptr;
int rhash, rsign;
size_t i;
if (salglen & 1)
return 0;
sigalgs = OPENSSL_malloc(salglen);
if (sigalgs == NULL)
return 0;
for (i = 0, sptr = sigalgs; i < salglen; i+=2)
{
rhash = tls12_find_id(*psig_nids++, tls12_md,
sizeof(tls12_md)/sizeof(tls12_lookup));
rsign = tls12_find_id(*psig_nids++, tls12_sig,
sizeof(tls12_sig)/sizeof(tls12_lookup));
if (rhash == -1 || rsign == -1)
goto err;
*sptr++ = rhash;
*sptr++ = rsign;
}
if (client)
{
if (c->client_sigalgs)
OPENSSL_free(c->client_sigalgs);
c->client_sigalgs = sigalgs;
c->client_sigalgslen = salglen;
}
else
{
if (c->conf_sigalgs)
OPENSSL_free(c->conf_sigalgs);
c->conf_sigalgs = sigalgs;
c->conf_sigalgslen = salglen;
}
return 1;
err:
OPENSSL_free(sigalgs);
return 0;
}
static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
{
int sig_nid;
size_t i;
if (default_nid == -1)
return 1;
sig_nid = X509_get_signature_nid(x);
if (default_nid)
return sig_nid == default_nid ? 1 : 0;
for (i = 0; i < c->shared_sigalgslen; i++)
if (sig_nid == c->shared_sigalgs[i].signandhash_nid)
return 1;
return 0;
}
/* Check to see if a certificate issuer name matches list of CA names */
static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
{
X509_NAME *nm;
int i;
nm = X509_get_issuer_name(x);
for (i = 0; i < sk_X509_NAME_num(names); i++)
{
if(!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
return 1;
}
return 0;
}
/* Check certificate chain is consistent with TLS extensions and is
* usable by server. This servers two purposes: it allows users to
* check chains before passing them to the server and it allows the
* server to check chains before attempting to use them.
*/
/* Flags which need to be set for a certificate when stict mode not set */
#define CERT_PKEY_VALID_FLAGS \
(CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
/* Strict mode flags */
#define CERT_PKEY_STRICT_FLAGS \
(CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
| CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
int idx)
{
int i;
int rv = 0;
int check_flags = 0, strict_mode;
CERT_PKEY *cpk = NULL;
CERT *c = s->cert;
unsigned int suiteb_flags = tls1_suiteb(s);
/* idx == -1 means checking server chains */
if (idx != -1)
{
/* idx == -2 means checking client certificate chains */
if (idx == -2)
{
cpk = c->key;
idx = cpk - c->pkeys;
}
else
cpk = c->pkeys + idx;
x = cpk->x509;
pk = cpk->privatekey;
chain = cpk->chain;
strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
/* If no cert or key, forget it */
if (!x || !pk)
goto end;
#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
/* Allow any certificate to pass test */
if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
{
rv = CERT_PKEY_STRICT_FLAGS|CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_VALID|CERT_PKEY_SIGN;
cpk->valid_flags = rv;
return rv;
}
#endif
}
else
{
if (!x || !pk)
goto end;
idx = ssl_cert_type(x, pk);
if (idx == -1)
goto end;
cpk = c->pkeys + idx;
if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
check_flags = CERT_PKEY_STRICT_FLAGS;
else
check_flags = CERT_PKEY_VALID_FLAGS;
strict_mode = 1;
}
if (suiteb_flags)
{
int ok;
if (check_flags)
check_flags |= CERT_PKEY_SUITEB;
ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
if (ok != X509_V_OK)
{
if (check_flags)
rv |= CERT_PKEY_SUITEB;
else
goto end;
}
}
/* Check all signature algorithms are consistent with
* signature algorithms extension if TLS 1.2 or later
* and strict mode.
*/
if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode)
{
int default_nid;
unsigned char rsign = 0;
if (c->peer_sigalgs)
default_nid = 0;
/* If no sigalgs extension use defaults from RFC5246 */
else
{
switch(idx)
{
case SSL_PKEY_RSA_ENC:
case SSL_PKEY_RSA_SIGN:
case SSL_PKEY_DH_RSA:
rsign = TLSEXT_signature_rsa;
default_nid = NID_sha1WithRSAEncryption;
break;
case SSL_PKEY_DSA_SIGN:
case SSL_PKEY_DH_DSA:
rsign = TLSEXT_signature_dsa;
default_nid = NID_dsaWithSHA1;
break;
case SSL_PKEY_ECC:
rsign = TLSEXT_signature_ecdsa;
default_nid = NID_ecdsa_with_SHA1;
break;
default:
default_nid = -1;
break;
}
}
/* If peer sent no signature algorithms extension and we
* have set preferred signature algorithms check we support
* sha1.
*/
if (default_nid > 0 && c->conf_sigalgs)
{
size_t j;
const unsigned char *p = c->conf_sigalgs;
for (j = 0; j < c->conf_sigalgslen; j += 2, p += 2)
{
if (p[0] == TLSEXT_hash_sha1 && p[1] == rsign)
break;
}
if (j == c->conf_sigalgslen)
{
if (check_flags)
goto skip_sigs;
else
goto end;
}
}
/* Check signature algorithm of each cert in chain */
if (!tls1_check_sig_alg(c, x, default_nid))
{
if (!check_flags) goto end;
}
else
rv |= CERT_PKEY_EE_SIGNATURE;
rv |= CERT_PKEY_CA_SIGNATURE;
for (i = 0; i < sk_X509_num(chain); i++)
{
if (!tls1_check_sig_alg(c, sk_X509_value(chain, i),
default_nid))
{
if (check_flags)
{
rv &= ~CERT_PKEY_CA_SIGNATURE;
break;
}
else
goto end;
}
}
}
/* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
else if(check_flags)
rv |= CERT_PKEY_EE_SIGNATURE|CERT_PKEY_CA_SIGNATURE;
skip_sigs:
/* Check cert parameters are consistent */
if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
rv |= CERT_PKEY_EE_PARAM;
else if (!check_flags)
goto end;
if (!s->server)
rv |= CERT_PKEY_CA_PARAM;
/* In strict mode check rest of chain too */
else if (strict_mode)
{
rv |= CERT_PKEY_CA_PARAM;
for (i = 0; i < sk_X509_num(chain); i++)
{
X509 *ca = sk_X509_value(chain, i);
if (!tls1_check_cert_param(s, ca, 0))
{
if (check_flags)
{
rv &= ~CERT_PKEY_CA_PARAM;
break;
}
else
goto end;
}
}
}
if (!s->server && strict_mode)
{
STACK_OF(X509_NAME) *ca_dn;
uint8_t check_type = 0;
switch (pk->type)
{
case EVP_PKEY_RSA:
check_type = TLS_CT_RSA_SIGN;
break;
case EVP_PKEY_DSA:
check_type = TLS_CT_DSS_SIGN;
break;
case EVP_PKEY_EC:
check_type = TLS_CT_ECDSA_SIGN;
break;
case EVP_PKEY_DH:
case EVP_PKEY_DHX:
{
int cert_type = X509_certificate_type(x, pk);
if (cert_type & EVP_PKS_RSA)
check_type = TLS_CT_RSA_FIXED_DH;
if (cert_type & EVP_PKS_DSA)
check_type = TLS_CT_DSS_FIXED_DH;
}
}
if (check_type)
{
if (s->s3->tmp.certificate_types &&
memchr(s->s3->tmp.certificate_types, check_type, s->s3->tmp.num_certificate_types))
{
rv |= CERT_PKEY_CERT_TYPE;
}
if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
goto end;
}
else
rv |= CERT_PKEY_CERT_TYPE;
ca_dn = s->s3->tmp.ca_names;
if (!sk_X509_NAME_num(ca_dn))
rv |= CERT_PKEY_ISSUER_NAME;
if (!(rv & CERT_PKEY_ISSUER_NAME))
{
if (ssl_check_ca_name(ca_dn, x))
rv |= CERT_PKEY_ISSUER_NAME;
}
if (!(rv & CERT_PKEY_ISSUER_NAME))
{
for (i = 0; i < sk_X509_num(chain); i++)
{
X509 *xtmp = sk_X509_value(chain, i);
if (ssl_check_ca_name(ca_dn, xtmp))
{
rv |= CERT_PKEY_ISSUER_NAME;
break;
}
}
}
if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
goto end;
}
else
rv |= CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE;
if (!check_flags || (rv & check_flags) == check_flags)
rv |= CERT_PKEY_VALID;
end:
if (TLS1_get_version(s) >= TLS1_2_VERSION)
{
if (cpk->valid_flags & CERT_PKEY_EXPLICIT_SIGN)
rv |= CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_SIGN;
else if (cpk->digest)
rv |= CERT_PKEY_SIGN;
}
else
rv |= CERT_PKEY_SIGN|CERT_PKEY_EXPLICIT_SIGN;
/* When checking a CERT_PKEY structure all flags are irrelevant
* if the chain is invalid.
*/
if (!check_flags)
{
if (rv & CERT_PKEY_VALID)
cpk->valid_flags = rv;
else
{
/* Preserve explicit sign flag, clear rest */
cpk->valid_flags &= CERT_PKEY_EXPLICIT_SIGN;
return 0;
}
}
return rv;
}
/* Set validity of certificates in an SSL structure */
void tls1_set_cert_validity(SSL *s)
{
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_ENC);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_RSA);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_DSA);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
}
/* User level utiity function to check a chain is suitable */
int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
{
return tls1_check_chain(s, x, pk, chain, -1);
}
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