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ext-libressl-portable/ssl/t1_lib.c
Steveice10 41de3f161a libressl: Update to 3.8.0
2023-06-04 17:13:21 -07:00

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/* $OpenBSD: t1_lib.c,v 1.197 2022/11/26 16:08:56 tb Exp $ */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <stdio.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/objects.h>
#include <openssl/ocsp.h>
#include "bytestring.h"
#include "ssl_local.h"
#include "ssl_sigalgs.h"
#include "ssl_tlsext.h"
static int tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert,
SSL_SESSION **psess);
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 == NULL)
return;
free(s->tlsext_session_ticket);
ssl3_free(s);
}
void
tls1_clear(SSL *s)
{
ssl3_clear(s);
s->version = s->method->version;
}
struct supported_group {
int nid;
int bits;
};
/*
* Supported groups (formerly known as named curves)
* https://www.iana.org/assignments/tls-parameters/#tls-parameters-8
*/
static const struct supported_group nid_list[] = {
[1] = {
.nid = NID_sect163k1,
.bits = 80,
},
[2] = {
.nid = NID_sect163r1,
.bits = 80,
},
[3] = {
.nid = NID_sect163r2,
.bits = 80,
},
[4] = {
.nid = NID_sect193r1,
.bits = 80,
},
[5] = {
.nid = NID_sect193r2,
.bits = 80,
},
[6] = {
.nid = NID_sect233k1,
.bits = 112,
},
[7] = {
.nid = NID_sect233r1,
.bits = 112,
},
[8] = {
.nid = NID_sect239k1,
.bits = 112,
},
[9] = {
.nid = NID_sect283k1,
.bits = 128,
},
[10] = {
.nid = NID_sect283r1,
.bits = 128,
},
[11] = {
.nid = NID_sect409k1,
.bits = 192,
},
[12] = {
.nid = NID_sect409r1,
.bits = 192,
},
[13] = {
.nid = NID_sect571k1,
.bits = 256,
},
[14] = {
.nid = NID_sect571r1,
.bits = 256,
},
[15] = {
.nid = NID_secp160k1,
.bits = 80,
},
[16] = {
.nid = NID_secp160r1,
.bits = 80,
},
[17] = {
.nid = NID_secp160r2,
.bits = 80,
},
[18] = {
.nid = NID_secp192k1,
.bits = 80,
},
[19] = {
.nid = NID_X9_62_prime192v1, /* aka secp192r1 */
.bits = 80,
},
[20] = {
.nid = NID_secp224k1,
.bits = 112,
},
[21] = {
.nid = NID_secp224r1,
.bits = 112,
},
[22] = {
.nid = NID_secp256k1,
.bits = 128,
},
[23] = {
.nid = NID_X9_62_prime256v1, /* aka secp256r1 */
.bits = 128,
},
[24] = {
.nid = NID_secp384r1,
.bits = 192,
},
[25] = {
.nid = NID_secp521r1,
.bits = 256,
},
[26] = {
.nid = NID_brainpoolP256r1,
.bits = 128,
},
[27] = {
.nid = NID_brainpoolP384r1,
.bits = 192,
},
[28] = {
.nid = NID_brainpoolP512r1,
.bits = 256,
},
[29] = {
.nid = NID_X25519,
.bits = 128,
},
};
#define NID_LIST_LEN (sizeof(nid_list) / sizeof(nid_list[0]))
#if 0
static const uint8_t ecformats_list[] = {
TLSEXT_ECPOINTFORMAT_uncompressed,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
};
#endif
static const uint8_t ecformats_default[] = {
TLSEXT_ECPOINTFORMAT_uncompressed,
};
#if 0
static const uint16_t ecgroups_list[] = {
29, /* X25519 (29) */
14, /* sect571r1 (14) */
13, /* sect571k1 (13) */
25, /* secp521r1 (25) */
28, /* brainpoolP512r1 (28) */
11, /* sect409k1 (11) */
12, /* sect409r1 (12) */
27, /* brainpoolP384r1 (27) */
24, /* secp384r1 (24) */
9, /* sect283k1 (9) */
10, /* sect283r1 (10) */
26, /* brainpoolP256r1 (26) */
22, /* secp256k1 (22) */
23, /* secp256r1 (23) */
8, /* sect239k1 (8) */
6, /* sect233k1 (6) */
7, /* sect233r1 (7) */
20, /* secp224k1 (20) */
21, /* secp224r1 (21) */
4, /* sect193r1 (4) */
5, /* sect193r2 (5) */
18, /* secp192k1 (18) */
19, /* secp192r1 (19) */
1, /* sect163k1 (1) */
2, /* sect163r1 (2) */
3, /* sect163r2 (3) */
15, /* secp160k1 (15) */
16, /* secp160r1 (16) */
17, /* secp160r2 (17) */
};
#endif
static const uint16_t ecgroups_client_default[] = {
29, /* X25519 (29) */
23, /* secp256r1 (23) */
24, /* secp384r1 (24) */
25, /* secp521r1 (25) */
};
static const uint16_t ecgroups_server_default[] = {
29, /* X25519 (29) */
23, /* secp256r1 (23) */
24, /* secp384r1 (24) */
};
int
tls1_ec_group_id2nid(uint16_t group_id, int *out_nid)
{
int nid;
if (group_id >= NID_LIST_LEN)
return 0;
if ((nid = nid_list[group_id].nid) == 0)
return 0;
*out_nid = nid;
return 1;
}
int
tls1_ec_group_id2bits(uint16_t group_id, int *out_bits)
{
int bits;
if (group_id >= NID_LIST_LEN)
return 0;
if ((bits = nid_list[group_id].bits) == 0)
return 0;
*out_bits = bits;
return 1;
}
int
tls1_ec_nid2group_id(int nid, uint16_t *out_group_id)
{
uint16_t group_id;
if (nid == 0)
return 0;
for (group_id = 0; group_id < NID_LIST_LEN; group_id++) {
if (nid_list[group_id].nid == nid) {
*out_group_id = group_id;
return 1;
}
}
return 0;
}
/*
* Return the appropriate format list. If client_formats is non-zero, return
* the client/session formats. Otherwise return the custom format list if one
* exists, or the default formats if a custom list has not been specified.
*/
void
tls1_get_formatlist(const SSL *s, int client_formats, const uint8_t **pformats,
size_t *pformatslen)
{
if (client_formats != 0) {
*pformats = s->session->tlsext_ecpointformatlist;
*pformatslen = s->session->tlsext_ecpointformatlist_length;
return;
}
*pformats = s->tlsext_ecpointformatlist;
*pformatslen = s->tlsext_ecpointformatlist_length;
if (*pformats == NULL) {
*pformats = ecformats_default;
*pformatslen = sizeof(ecformats_default);
}
}
/*
* Return the appropriate group list. If client_groups is non-zero, return
* the client/session groups. Otherwise return the custom group list if one
* exists, or the default groups if a custom list has not been specified.
*/
void
tls1_get_group_list(const SSL *s, int client_groups, const uint16_t **pgroups,
size_t *pgroupslen)
{
if (client_groups != 0) {
*pgroups = s->session->tlsext_supportedgroups;
*pgroupslen = s->session->tlsext_supportedgroups_length;
return;
}
*pgroups = s->tlsext_supportedgroups;
*pgroupslen = s->tlsext_supportedgroups_length;
if (*pgroups != NULL)
return;
if (!s->server) {
*pgroups = ecgroups_client_default;
*pgroupslen = sizeof(ecgroups_client_default) / 2;
} else {
*pgroups = ecgroups_server_default;
*pgroupslen = sizeof(ecgroups_server_default) / 2;
}
}
static int
tls1_get_group_lists(const SSL *ssl, const uint16_t **pref, size_t *preflen,
const uint16_t **supp, size_t *supplen)
{
unsigned long server_pref;
/* Cannot do anything on the client side. */
if (!ssl->server)
return 0;
server_pref = (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE);
tls1_get_group_list(ssl, (server_pref == 0), pref, preflen);
tls1_get_group_list(ssl, (server_pref != 0), supp, supplen);
return 1;
}
static int
tls1_group_id_present(uint16_t group_id, const uint16_t *list, size_t list_len)
{
size_t i;
for (i = 0; i < list_len; i++) {
if (group_id == list[i])
return 1;
}
return 0;
}
int
tls1_count_shared_groups(const SSL *ssl, size_t *out_count)
{
size_t count, preflen, supplen, i;
const uint16_t *pref, *supp;
if (!tls1_get_group_lists(ssl, &pref, &preflen, &supp, &supplen))
return 0;
count = 0;
for (i = 0; i < preflen; i++) {
if (!tls1_group_id_present(pref[i], supp, supplen))
continue;
if (!ssl_security_shared_group(ssl, pref[i]))
continue;
count++;
}
*out_count = count;
return 1;
}
static int
tls1_group_by_index(const SSL *ssl, size_t n, int *out_nid,
int (*ssl_security_fn)(const SSL *, uint16_t))
{
size_t count, preflen, supplen, i;
const uint16_t *pref, *supp;
if (!tls1_get_group_lists(ssl, &pref, &preflen, &supp, &supplen))
return 0;
count = 0;
for (i = 0; i < preflen; i++) {
if (!tls1_group_id_present(pref[i], supp, supplen))
continue;
if (!ssl_security_fn(ssl, pref[i]))
continue;
if (count++ == n)
return tls1_ec_group_id2nid(pref[i], out_nid);
}
return 0;
}
int
tls1_get_shared_group_by_index(const SSL *ssl, size_t index, int *out_nid)
{
return tls1_group_by_index(ssl, index, out_nid,
ssl_security_shared_group);
}
int
tls1_get_supported_group(const SSL *ssl, int *out_nid)
{
return tls1_group_by_index(ssl, 0, out_nid,
ssl_security_supported_group);
}
int
tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len,
const int *groups, size_t ngroups)
{
uint16_t *group_ids;
size_t i;
if ((group_ids = calloc(ngroups, sizeof(uint16_t))) == NULL)
return 0;
for (i = 0; i < ngroups; i++) {
if (!tls1_ec_nid2group_id(groups[i], &group_ids[i])) {
free(group_ids);
return 0;
}
}
free(*out_group_ids);
*out_group_ids = group_ids;
*out_group_ids_len = ngroups;
return 1;
}
int
tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
const char *groups)
{
uint16_t *new_group_ids, *group_ids = NULL;
size_t ngroups = 0;
char *gs, *p, *q;
int nid;
if ((gs = strdup(groups)) == NULL)
return 0;
q = gs;
while ((p = strsep(&q, ":")) != NULL) {
nid = OBJ_sn2nid(p);
if (nid == NID_undef)
nid = OBJ_ln2nid(p);
if (nid == NID_undef)
nid = EC_curve_nist2nid(p);
if (nid == NID_undef)
goto err;
if ((new_group_ids = reallocarray(group_ids, ngroups + 1,
sizeof(uint16_t))) == NULL)
goto err;
group_ids = new_group_ids;
if (!tls1_ec_nid2group_id(nid, &group_ids[ngroups]))
goto err;
ngroups++;
}
free(gs);
free(*out_group_ids);
*out_group_ids = group_ids;
*out_group_ids_len = ngroups;
return 1;
err:
free(gs);
free(group_ids);
return 0;
}
/* Check that a group is one of our preferences. */
int
tls1_check_group(SSL *s, uint16_t group_id)
{
const uint16_t *groups;
size_t groupslen, i;
tls1_get_group_list(s, 0, &groups, &groupslen);
for (i = 0; i < groupslen; i++) {
if (!ssl_security_supported_group(s, groups[i]))
continue;
if (groups[i] == group_id)
return 1;
}
return 0;
}
/* For an EC key set TLS ID and required compression based on parameters. */
static int
tls1_set_ec_id(uint16_t *group_id, uint8_t *comp_id, EC_KEY *ec)
{
const EC_GROUP *grp;
const EC_METHOD *meth;
int prime_field;
int nid;
if (ec == NULL)
return (0);
/* Determine whether the group is defined over a prime field. */
if ((grp = EC_KEY_get0_group(ec)) == NULL)
return (0);
if ((meth = EC_GROUP_method_of(grp)) == NULL)
return (0);
prime_field = (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field);
/* Determine group ID. */
nid = EC_GROUP_get_curve_name(grp);
/* If we have an ID set it, otherwise set arbitrary explicit group. */
if (!tls1_ec_nid2group_id(nid, group_id))
*group_id = prime_field ? 0xff01 : 0xff02;
if (comp_id == NULL)
return (1);
/* Specify the compression identifier. */
if (EC_KEY_get0_public_key(ec) == NULL)
return (0);
*comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) {
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
if (prime_field)
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
}
return (1);
}
/* Check that an EC key is compatible with extensions. */
static int
tls1_check_ec_key(SSL *s, const uint16_t *group_id, const uint8_t *comp_id)
{
size_t groupslen, formatslen, i;
const uint16_t *groups;
const uint8_t *formats;
/*
* Check point formats extension if present, otherwise everything
* is supported (see RFC4492).
*/
tls1_get_formatlist(s, 1, &formats, &formatslen);
if (comp_id != NULL && formats != NULL) {
for (i = 0; i < formatslen; i++) {
if (formats[i] == *comp_id)
break;
}
if (i == formatslen)
return (0);
}
/*
* Check group list if present, otherwise everything is supported.
*/
tls1_get_group_list(s, 1, &groups, &groupslen);
if (group_id != NULL && groups != NULL) {
for (i = 0; i < groupslen; i++) {
if (groups[i] == *group_id)
break;
}
if (i == groupslen)
return (0);
}
return (1);
}
/* Check EC server key is compatible with client extensions. */
int
tls1_check_ec_server_key(SSL *s)
{
SSL_CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC;
uint16_t group_id;
uint8_t comp_id;
EC_KEY *eckey;
EVP_PKEY *pkey;
if (cpk->x509 == NULL || cpk->privatekey == NULL)
return (0);
if ((pkey = X509_get0_pubkey(cpk->x509)) == NULL)
return (0);
if ((eckey = EVP_PKEY_get0_EC_KEY(pkey)) == NULL)
return (0);
if (!tls1_set_ec_id(&group_id, &comp_id, eckey))
return (0);
return tls1_check_ec_key(s, &group_id, &comp_id);
}
int
ssl_check_clienthello_tlsext_early(SSL *s)
{
int ret = SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
/* 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.
*/
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:
default:
return 1;
}
}
int
ssl_check_clienthello_tlsext_late(SSL *s)
{
int ret = SSL_TLSEXT_ERR_OK;
int al = 0; /* XXX gcc3 */
/* 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;
SSL_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;
ret = SSL_TLSEXT_ERR_OK;
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;
free(s->tlsext_ocsp_resp);
s->tlsext_ocsp_resp = NULL;
s->tlsext_ocsp_resp_len = 0;
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:
default:
return 1;
}
}
/* Since the server cache lookup is done early on in the processing of the
* ClientHello, and other operations depend on the result, we need to handle
* any TLS session ticket extension at the same time.
*
* ext_block: a CBS for the ClientHello extensions block.
* 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:
* TLS1_TICKET_FATAL_ERROR: error from parsing or decrypting the ticket.
* TLS1_TICKET_NONE: no ticket was found (or was ignored, based on settings).
* TLS1_TICKET_EMPTY: a zero length extension was found, indicating that the
* client supports session tickets but doesn't currently have one to offer.
* TLS1_TICKET_NOT_DECRYPTED: either s->tls_session_secret_cb was
* set, or a ticket was offered but couldn't be decrypted because of a
* non-fatal error.
* TLS1_TICKET_DECRYPTED: 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, CBS *ext_block, int *alert, SSL_SESSION **ret)
{
CBS extensions, ext_data;
uint16_t ext_type = 0;
s->tlsext_ticket_expected = 0;
*ret = NULL;
/*
* If tickets disabled behave as if no ticket present to permit stateful
* resumption.
*/
if (SSL_get_options(s) & SSL_OP_NO_TICKET)
return TLS1_TICKET_NONE;
/*
* An empty extensions block is valid, but obviously does not contain
* a session ticket.
*/
if (CBS_len(ext_block) == 0)
return TLS1_TICKET_NONE;
if (!CBS_get_u16_length_prefixed(ext_block, &extensions)) {
*alert = SSL_AD_DECODE_ERROR;
return TLS1_TICKET_FATAL_ERROR;
}
while (CBS_len(&extensions) > 0) {
if (!CBS_get_u16(&extensions, &ext_type) ||
!CBS_get_u16_length_prefixed(&extensions, &ext_data)) {
*alert = SSL_AD_DECODE_ERROR;
return TLS1_TICKET_FATAL_ERROR;
}
if (ext_type == TLSEXT_TYPE_session_ticket)
break;
}
if (ext_type != TLSEXT_TYPE_session_ticket)
return TLS1_TICKET_NONE;
if (CBS_len(&ext_data) == 0) {
/*
* The client will accept a ticket but does not currently
* have one.
*/
s->tlsext_ticket_expected = 1;
return TLS1_TICKET_EMPTY;
}
if (s->tls_session_secret_cb != NULL) {
/*
* Indicate that the ticket could not be decrypted rather than
* generating the session from ticket now, trigger abbreviated
* handshake based on external mechanism to calculate the master
* secret later.
*/
return TLS1_TICKET_NOT_DECRYPTED;
}
return tls_decrypt_ticket(s, &ext_data, alert, ret);
}
/* tls_decrypt_ticket attempts to decrypt a session ticket.
*
* ticket: a CBS containing the body of the session ticket extension.
* psess: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* Returns:
* TLS1_TICKET_FATAL_ERROR: error from parsing or decrypting the ticket.
* TLS1_TICKET_NOT_DECRYPTED: the ticket couldn't be decrypted.
* TLS1_TICKET_DECRYPTED: a ticket was decrypted and *psess was set.
*/
static int
tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, SSL_SESSION **psess)
{
CBS ticket_name, ticket_iv, ticket_encdata, ticket_hmac;
SSL_SESSION *sess = NULL;
unsigned char *sdec = NULL;
size_t sdec_len = 0;
const unsigned char *p;
unsigned char hmac[EVP_MAX_MD_SIZE];
HMAC_CTX *hctx = NULL;
EVP_CIPHER_CTX *cctx = NULL;
SSL_CTX *tctx = s->initial_ctx;
int slen, hlen;
int alert_desc = SSL_AD_INTERNAL_ERROR;
int ret = TLS1_TICKET_FATAL_ERROR;
*psess = NULL;
if (!CBS_get_bytes(ticket, &ticket_name, 16))
goto derr;
/*
* Initialize session ticket encryption and HMAC contexts.
*/
if ((cctx = EVP_CIPHER_CTX_new()) == NULL)
goto err;
if ((hctx = HMAC_CTX_new()) == NULL)
goto err;
if (tctx->tlsext_ticket_key_cb != NULL) {
int rv;
/*
* The API guarantees EVP_MAX_IV_LENGTH bytes of space for
* the iv to tlsext_ticket_key_cb(). Since the total space
* required for a session cookie is never less than this,
* this check isn't too strict. The exact check comes later.
*/
if (CBS_len(ticket) < EVP_MAX_IV_LENGTH)
goto derr;
if ((rv = tctx->tlsext_ticket_key_cb(s,
(unsigned char *)CBS_data(&ticket_name),
(unsigned char *)CBS_data(ticket), cctx, hctx, 0)) < 0)
goto err;
if (rv == 0)
goto derr;
if (rv == 2) {
/* Renew ticket. */
s->tlsext_ticket_expected = 1;
}
/*
* Now that the cipher context is initialised, we can extract
* the IV since its length is known.
*/
if (!CBS_get_bytes(ticket, &ticket_iv,
EVP_CIPHER_CTX_iv_length(cctx)))
goto derr;
} else {
/* Check that the key name matches. */
if (!CBS_mem_equal(&ticket_name,
tctx->tlsext_tick_key_name,
sizeof(tctx->tlsext_tick_key_name)))
goto derr;
if (!CBS_get_bytes(ticket, &ticket_iv,
EVP_CIPHER_iv_length(EVP_aes_128_cbc())))
goto derr;
if (!EVP_DecryptInit_ex(cctx, EVP_aes_128_cbc(), NULL,
tctx->tlsext_tick_aes_key, CBS_data(&ticket_iv)))
goto err;
if (!HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key,
sizeof(tctx->tlsext_tick_hmac_key), EVP_sha256(),
NULL))
goto err;
}
/*
* Attempt to process session ticket.
*/
if ((hlen = HMAC_size(hctx)) < 0)
goto err;
if (hlen > CBS_len(ticket))
goto derr;
if (!CBS_get_bytes(ticket, &ticket_encdata, CBS_len(ticket) - hlen))
goto derr;
if (!CBS_get_bytes(ticket, &ticket_hmac, hlen))
goto derr;
if (CBS_len(ticket) != 0) {
alert_desc = SSL_AD_DECODE_ERROR;
goto err;
}
/* Check HMAC of encrypted ticket. */
if (HMAC_Update(hctx, CBS_data(&ticket_name),
CBS_len(&ticket_name)) <= 0)
goto err;
if (HMAC_Update(hctx, CBS_data(&ticket_iv),
CBS_len(&ticket_iv)) <= 0)
goto err;
if (HMAC_Update(hctx, CBS_data(&ticket_encdata),
CBS_len(&ticket_encdata)) <= 0)
goto err;
if (HMAC_Final(hctx, hmac, &hlen) <= 0)
goto err;
if (!CBS_mem_equal(&ticket_hmac, hmac, hlen))
goto derr;
/* Attempt to decrypt session data. */
sdec_len = CBS_len(&ticket_encdata);
if ((sdec = calloc(1, sdec_len)) == NULL)
goto err;
if (EVP_DecryptUpdate(cctx, sdec, &slen, CBS_data(&ticket_encdata),
CBS_len(&ticket_encdata)) <= 0)
goto derr;
if (EVP_DecryptFinal_ex(cctx, sdec + slen, &hlen) <= 0)
goto derr;
slen += hlen;
/*
* For session parse failures, indicate that we need to send a new
* ticket.
*/
p = sdec;
if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL)
goto derr;
*psess = sess;
sess = NULL;
ret = TLS1_TICKET_DECRYPTED;
goto done;
derr:
ERR_clear_error();
s->tlsext_ticket_expected = 1;
ret = TLS1_TICKET_NOT_DECRYPTED;
goto done;
err:
*alert = alert_desc;
ret = TLS1_TICKET_FATAL_ERROR;
goto done;
done:
freezero(sdec, sdec_len);
EVP_CIPHER_CTX_free(cctx);
HMAC_CTX_free(hctx);
SSL_SESSION_free(sess);
return ret;
}
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