/*
* Copyright (C) 2004-2015 Free Software Foundation, Inc.
* Copyright (C) 2015-2017 Red Hat, Inc.
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS.
*
* The GnuTLS is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see
*
*/
/* Here lies the code of the gnutls_*_set_priority() functions.
*/
#include "gnutls_int.h"
#include "algorithms.h"
#include "errors.h"
#include
#include
#include
#include
#include "fips.h"
#include "errno.h"
#include "ext/srp.h"
#include
#define MAX_ELEMENTS 64
/* This function is used by the test suite */
char *_gnutls_resolve_priorities(const char* priorities);
const char *_gnutls_default_priority_string = DEFAULT_PRIORITY_STRING;
static void prio_remove(priority_st * priority_list, unsigned int algo);
static void prio_add(priority_st * priority_list, unsigned int algo);
static void
break_list(char *etag,
char *broken_etag[MAX_ELEMENTS], int *size);
typedef void (bulk_rmadd_func) (priority_st * priority_list, const int *);
inline static void _set_priority(priority_st * st, const int *list)
{
int num = 0, i;
while (list[num] != 0)
num++;
if (num > MAX_ALGOS)
num = MAX_ALGOS;
st->algorithms = num;
for (i = 0; i < num; i++) {
st->priority[i] = list[i];
}
return;
}
inline static void _add_priority(priority_st * st, const int *list)
{
int num, i, j, init;
init = i = st->algorithms;
for (num = 0; list[num] != 0; ++num) {
if (i + 1 > MAX_ALGOS) {
return;
}
for (j = 0; j < init; j++) {
if (st->priority[j] == (unsigned) list[num]) {
break;
}
}
if (j == init) {
st->priority[i++] = list[num];
st->algorithms++;
}
}
return;
}
static void _clear_priorities(priority_st * st, const int *list)
{
memset(st, 0, sizeof(*st));
}
static void _clear_given_priorities(priority_st * st, const int *list)
{
unsigned i;
for (i=0;list[i]!=0;i++) {
prio_remove(st, list[i]);
}
}
static const int _supported_groups_dh[] = {
GNUTLS_GROUP_FFDHE2048,
GNUTLS_GROUP_FFDHE3072,
GNUTLS_GROUP_FFDHE4096,
GNUTLS_GROUP_FFDHE6144,
GNUTLS_GROUP_FFDHE8192,
0
};
static const int _supported_groups_ecdh[] = {
GNUTLS_GROUP_SECP256R1,
GNUTLS_GROUP_SECP384R1,
GNUTLS_GROUP_SECP521R1,
GNUTLS_GROUP_X25519, /* draft-ietf-tls-rfc4492bis */
0
};
static const int _supported_groups_normal[] = {
GNUTLS_GROUP_SECP256R1,
GNUTLS_GROUP_SECP384R1,
GNUTLS_GROUP_SECP521R1,
GNUTLS_GROUP_X25519, /* draft-ietf-tls-rfc4492bis */
/* These should stay last as our default behavior
* is to send key shares for two top types (GNUTLS_KEY_SHARE_TOP2)
* and we wouldn't want to have these sent by all clients
* by default as they are quite expensive CPU-wise. */
GNUTLS_GROUP_FFDHE2048,
GNUTLS_GROUP_FFDHE3072,
GNUTLS_GROUP_FFDHE4096,
GNUTLS_GROUP_FFDHE6144,
GNUTLS_GROUP_FFDHE8192,
0
};
static const int* supported_groups_normal = _supported_groups_normal;
static const int _supported_groups_secure128[] = {
GNUTLS_GROUP_SECP256R1,
GNUTLS_GROUP_SECP384R1,
GNUTLS_GROUP_SECP521R1,
GNUTLS_GROUP_X25519, /* draft-ietf-tls-rfc4492bis */
GNUTLS_GROUP_FFDHE2048,
GNUTLS_GROUP_FFDHE3072,
GNUTLS_GROUP_FFDHE4096,
GNUTLS_GROUP_FFDHE6144,
GNUTLS_GROUP_FFDHE8192,
0
};
static const int* supported_groups_secure128 = _supported_groups_secure128;
static const int _supported_groups_suiteb128[] = {
GNUTLS_GROUP_SECP256R1,
GNUTLS_GROUP_SECP384R1,
0
};
static const int* supported_groups_suiteb128 = _supported_groups_suiteb128;
static const int _supported_groups_suiteb192[] = {
GNUTLS_GROUP_SECP384R1,
0
};
static const int* supported_groups_suiteb192 = _supported_groups_suiteb192;
static const int _supported_groups_secure192[] = {
GNUTLS_GROUP_SECP384R1,
GNUTLS_GROUP_SECP521R1,
GNUTLS_GROUP_FFDHE8192,
0
};
static const int* supported_groups_secure192 = _supported_groups_secure192;
static const int protocol_priority[] = {
GNUTLS_TLS1_3,
GNUTLS_TLS1_2,
GNUTLS_TLS1_1,
GNUTLS_TLS1_0,
GNUTLS_DTLS1_2,
GNUTLS_DTLS1_0,
0
};
/* contains all the supported TLS protocols, intended to be used for eliminating them
*/
static const int stream_protocol_priority[] = {
GNUTLS_TLS1_3,
GNUTLS_TLS1_2,
GNUTLS_TLS1_1,
GNUTLS_TLS1_0,
0
};
/* contains all the supported DTLS protocols, intended to be used for eliminating them
*/
static const int dgram_protocol_priority[] = {
GNUTLS_DTLS1_2,
GNUTLS_DTLS1_0,
GNUTLS_DTLS0_9,
0
};
static const int dtls_protocol_priority[] = {
GNUTLS_DTLS1_2,
GNUTLS_DTLS1_0,
0
};
static const int _protocol_priority_suiteb[] = {
GNUTLS_TLS1_2,
0
};
static const int* protocol_priority_suiteb = _protocol_priority_suiteb;
static const int _kx_priority_performance[] = {
GNUTLS_KX_RSA,
#ifdef ENABLE_ECDHE
GNUTLS_KX_ECDHE_ECDSA,
GNUTLS_KX_ECDHE_RSA,
#endif
#ifdef ENABLE_DHE
GNUTLS_KX_DHE_RSA,
#endif
0
};
static const int* kx_priority_performance = _kx_priority_performance;
static const int _kx_priority_pfs[] = {
#ifdef ENABLE_ECDHE
GNUTLS_KX_ECDHE_ECDSA,
GNUTLS_KX_ECDHE_RSA,
#endif
#ifdef ENABLE_DHE
GNUTLS_KX_DHE_RSA,
#endif
0
};
static const int* kx_priority_pfs = _kx_priority_pfs;
static const int _kx_priority_suiteb[] = {
GNUTLS_KX_ECDHE_ECDSA,
0
};
static const int* kx_priority_suiteb = _kx_priority_suiteb;
static const int _kx_priority_secure[] = {
/* The ciphersuites that offer forward secrecy take
* precedence
*/
#ifdef ENABLE_ECDHE
GNUTLS_KX_ECDHE_ECDSA,
GNUTLS_KX_ECDHE_RSA,
#endif
GNUTLS_KX_RSA,
/* KX-RSA is now ahead of DHE-RSA and DHE-DSS due to the compatibility
* issues the DHE ciphersuites have. That is, one cannot enforce a specific
* security level without dropping the connection.
*/
#ifdef ENABLE_DHE
GNUTLS_KX_DHE_RSA,
#endif
/* GNUTLS_KX_ANON_DH: Man-in-the-middle prone, don't add!
*/
0
};
static const int* kx_priority_secure = _kx_priority_secure;
static const int _cipher_priority_performance_default[] = {
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_CHACHA20_POLY1305,
GNUTLS_CIPHER_AES_128_CCM,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_128_CBC,
GNUTLS_CIPHER_AES_256_CBC,
0
};
static const int _cipher_priority_performance_no_aesni[] = {
GNUTLS_CIPHER_CHACHA20_POLY1305,
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_AES_128_CCM,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_128_CBC,
GNUTLS_CIPHER_AES_256_CBC,
0
};
/* If GCM and AES acceleration is available then prefer
* them over anything else. Overall we prioritise AEAD
* over legacy ciphers, and 256-bit over 128 (for future
* proof).
*/
static const int _cipher_priority_normal_default[] = {
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_CHACHA20_POLY1305,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_256_CBC,
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_128_CCM,
GNUTLS_CIPHER_AES_128_CBC,
0
};
static const int cipher_priority_performance_fips[] = {
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_128_CCM,
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_128_CBC,
GNUTLS_CIPHER_AES_256_CBC,
0
};
static const int cipher_priority_normal_fips[] = {
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_256_CBC,
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_128_CBC,
GNUTLS_CIPHER_AES_128_CCM,
0
};
static const int _cipher_priority_suiteb128[] = {
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_AES_128_GCM,
0
};
static const int* cipher_priority_suiteb128 = _cipher_priority_suiteb128;
static const int _cipher_priority_suiteb192[] = {
GNUTLS_CIPHER_AES_256_GCM,
0
};
static const int* cipher_priority_suiteb192 = _cipher_priority_suiteb192;
static const int _cipher_priority_secure128[] = {
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_CHACHA20_POLY1305,
GNUTLS_CIPHER_AES_256_CBC,
GNUTLS_CIPHER_AES_256_CCM,
GNUTLS_CIPHER_AES_128_GCM,
GNUTLS_CIPHER_AES_128_CBC,
GNUTLS_CIPHER_AES_128_CCM,
0
};
static const int *cipher_priority_secure128 = _cipher_priority_secure128;
static const int _cipher_priority_secure192[] = {
GNUTLS_CIPHER_AES_256_GCM,
GNUTLS_CIPHER_CHACHA20_POLY1305,
GNUTLS_CIPHER_AES_256_CBC,
GNUTLS_CIPHER_AES_256_CCM,
0
};
static const int* cipher_priority_secure192 = _cipher_priority_secure192;
static const int _sign_priority_default[] = {
GNUTLS_SIGN_RSA_SHA256,
GNUTLS_SIGN_RSA_PSS_SHA256,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA256,
GNUTLS_SIGN_ECDSA_SHA256,
GNUTLS_SIGN_ECDSA_SECP256R1_SHA256,
GNUTLS_SIGN_EDDSA_ED25519,
GNUTLS_SIGN_RSA_SHA384,
GNUTLS_SIGN_RSA_PSS_SHA384,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA384,
GNUTLS_SIGN_ECDSA_SHA384,
GNUTLS_SIGN_ECDSA_SECP384R1_SHA384,
GNUTLS_SIGN_RSA_SHA512,
GNUTLS_SIGN_RSA_PSS_SHA512,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA512,
GNUTLS_SIGN_ECDSA_SHA512,
GNUTLS_SIGN_ECDSA_SECP521R1_SHA512,
GNUTLS_SIGN_RSA_SHA1,
GNUTLS_SIGN_ECDSA_SHA1,
0
};
static const int* sign_priority_default = _sign_priority_default;
static const int _sign_priority_suiteb128[] = {
GNUTLS_SIGN_ECDSA_SHA256,
GNUTLS_SIGN_ECDSA_SECP256R1_SHA256,
GNUTLS_SIGN_ECDSA_SHA384,
GNUTLS_SIGN_ECDSA_SECP384R1_SHA384,
0
};
static const int* sign_priority_suiteb128 = _sign_priority_suiteb128;
static const int _sign_priority_suiteb192[] = {
GNUTLS_SIGN_ECDSA_SHA384,
GNUTLS_SIGN_ECDSA_SECP384R1_SHA384,
0
};
static const int* sign_priority_suiteb192 = _sign_priority_suiteb192;
static const int _sign_priority_secure128[] = {
GNUTLS_SIGN_RSA_SHA256,
GNUTLS_SIGN_RSA_PSS_SHA256,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA256,
GNUTLS_SIGN_ECDSA_SHA256,
GNUTLS_SIGN_ECDSA_SECP256R1_SHA256,
GNUTLS_SIGN_EDDSA_ED25519,
GNUTLS_SIGN_RSA_SHA384,
GNUTLS_SIGN_RSA_PSS_SHA384,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA384,
GNUTLS_SIGN_ECDSA_SHA384,
GNUTLS_SIGN_ECDSA_SECP384R1_SHA384,
GNUTLS_SIGN_RSA_SHA512,
GNUTLS_SIGN_RSA_PSS_SHA512,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA512,
GNUTLS_SIGN_ECDSA_SHA512,
GNUTLS_SIGN_ECDSA_SECP521R1_SHA512,
0
};
static const int* sign_priority_secure128 = _sign_priority_secure128;
static const int _sign_priority_secure192[] = {
GNUTLS_SIGN_RSA_SHA384,
GNUTLS_SIGN_RSA_PSS_SHA384,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA384,
GNUTLS_SIGN_ECDSA_SHA384,
GNUTLS_SIGN_ECDSA_SECP384R1_SHA384,
GNUTLS_SIGN_RSA_SHA512,
GNUTLS_SIGN_RSA_PSS_SHA512,
GNUTLS_SIGN_RSA_PSS_RSAE_SHA512,
GNUTLS_SIGN_ECDSA_SHA512,
GNUTLS_SIGN_ECDSA_SECP521R1_SHA512,
0
};
static const int* sign_priority_secure192 = _sign_priority_secure192;
static const int mac_priority_normal_default[] = {
GNUTLS_MAC_SHA1,
GNUTLS_MAC_AEAD,
0
};
static const int mac_priority_normal_fips[] = {
GNUTLS_MAC_SHA1,
GNUTLS_MAC_AEAD,
0
};
static const int *cipher_priority_performance = _cipher_priority_performance_default;
static const int *cipher_priority_normal = _cipher_priority_normal_default;
static const int *mac_priority_normal = mac_priority_normal_default;
/* if called with replace the default priorities with the FIPS140 ones */
void _gnutls_priority_update_fips(void)
{
cipher_priority_performance = cipher_priority_performance_fips;
cipher_priority_normal = cipher_priority_normal_fips;
mac_priority_normal = mac_priority_normal_fips;
}
void _gnutls_priority_update_non_aesni(void)
{
/* if we have no AES acceleration in performance mode
* prefer fast stream ciphers */
if (_gnutls_fips_mode_enabled() == 0) {
cipher_priority_performance = _cipher_priority_performance_no_aesni;
}
}
static const int _mac_priority_suiteb[] = {
GNUTLS_MAC_AEAD,
0
};
static const int* mac_priority_suiteb = _mac_priority_suiteb;
static const int _mac_priority_secure128[] = {
GNUTLS_MAC_SHA1,
GNUTLS_MAC_AEAD,
0
};
static const int* mac_priority_secure128 = _mac_priority_secure128;
static const int _mac_priority_secure192[] = {
GNUTLS_MAC_AEAD,
0
};
static const int* mac_priority_secure192 = _mac_priority_secure192;
static const int cert_type_priority_default[] = {
GNUTLS_CRT_X509,
0
};
static const int cert_type_priority_all[] = {
GNUTLS_CRT_X509,
GNUTLS_CRT_RAWPK,
0
};
typedef void (rmadd_func) (priority_st * priority_list, unsigned int alg);
static void prio_remove(priority_st * priority_list, unsigned int algo)
{
unsigned int i;
for (i = 0; i < priority_list->algorithms; i++) {
if (priority_list->priority[i] == algo) {
priority_list->algorithms--;
if ((priority_list->algorithms - i) > 0)
memmove(&priority_list->priority[i],
&priority_list->priority[i + 1],
(priority_list->algorithms -
i) *
sizeof(priority_list->
priority[0]));
priority_list->priority[priority_list->
algorithms] = 0;
break;
}
}
return;
}
static void prio_add(priority_st * priority_list, unsigned int algo)
{
unsigned int i, l = priority_list->algorithms;
if (l >= MAX_ALGOS)
return; /* can't add it anyway */
for (i = 0; i < l; ++i) {
if (algo == priority_list->priority[i])
return; /* if it exists */
}
priority_list->priority[l] = algo;
priority_list->algorithms++;
return;
}
/**
* gnutls_priority_set:
* @session: is a #gnutls_session_t type.
* @priority: is a #gnutls_priority_t type.
*
* Sets the priorities to use on the ciphers, key exchange methods,
* and macs.
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code.
**/
int
gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority)
{
if (priority == NULL) {
gnutls_assert();
return GNUTLS_E_NO_CIPHER_SUITES;
}
if (session->internals.priorities)
gnutls_priority_deinit(session->internals.priorities);
session->internals.priorities = priority;
gnutls_atomic_increment(&priority->usage_cnt);
/* set the current version to the first in the chain.
* This will be overridden later.
*/
if (session->internals.priorities->protocol.algorithms > 0) {
if (_gnutls_set_current_version(session,
session->internals.priorities->
protocol.priority[0]) < 0) {
return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_VERSION_PACKET);
}
}
if (priority->no_tickets != 0) {
/* when PFS is explicitly requested, disable session tickets */
session->internals.flags |= GNUTLS_NO_TICKETS;
}
if (session->internals.priorities->protocol.algorithms == 0 ||
session->internals.priorities->cs.size == 0)
return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
ADD_PROFILE_VFLAGS(session, priority->additional_verify_flags);
/* mirror variables */
#undef COPY_TO_INTERNALS
#define COPY_TO_INTERNALS(xx) session->internals.xx = priority->_##xx
COPY_TO_INTERNALS(allow_large_records);
COPY_TO_INTERNALS(no_etm);
COPY_TO_INTERNALS(no_ext_master_secret);
COPY_TO_INTERNALS(allow_key_usage_violation);
COPY_TO_INTERNALS(allow_wrong_pms);
COPY_TO_INTERNALS(dumbfw);
COPY_TO_INTERNALS(dh_prime_bits);
return 0;
}
#define LEVEL_NONE "NONE"
#define LEVEL_NORMAL "NORMAL"
#define LEVEL_PFS "PFS"
#define LEVEL_PERFORMANCE "PERFORMANCE"
#define LEVEL_SECURE128 "SECURE128"
#define LEVEL_SECURE192 "SECURE192"
#define LEVEL_SECURE256 "SECURE256"
#define LEVEL_SUITEB128 "SUITEB128"
#define LEVEL_SUITEB192 "SUITEB192"
#define LEVEL_LEGACY "LEGACY"
struct priority_groups_st {
const char *name;
const char *alias;
const int **proto_list;
const int **cipher_list;
const int **mac_list;
const int **kx_list;
const int **sign_list;
const int **group_list;
unsigned profile;
int sec_param;
bool no_tickets;
};
static const struct priority_groups_st pgroups[] =
{
{.name = LEVEL_NORMAL,
.cipher_list = &cipher_priority_normal,
.mac_list = &mac_priority_normal,
.kx_list = &kx_priority_secure,
.sign_list = &sign_priority_default,
.group_list = &supported_groups_normal,
.profile = GNUTLS_PROFILE_LOW,
.sec_param = GNUTLS_SEC_PARAM_WEAK
},
{.name = LEVEL_PFS,
.cipher_list = &cipher_priority_normal,
.mac_list = &mac_priority_secure128,
.kx_list = &kx_priority_pfs,
.sign_list = &sign_priority_default,
.group_list = &supported_groups_normal,
.profile = GNUTLS_PROFILE_LOW,
.sec_param = GNUTLS_SEC_PARAM_WEAK,
.no_tickets = 1
},
{.name = LEVEL_SECURE128,
.alias = "SECURE",
.cipher_list = &cipher_priority_secure128,
.mac_list = &mac_priority_secure128,
.kx_list = &kx_priority_secure,
.sign_list = &sign_priority_secure128,
.group_list = &supported_groups_secure128,
/* The profile should have been HIGH but if we don't allow
* SHA-1 (80-bits) as signature algorithm we are not able
* to connect anywhere with this level */
.profile = GNUTLS_PROFILE_LOW,
.sec_param = GNUTLS_SEC_PARAM_LOW
},
{.name = LEVEL_SECURE192,
.alias = LEVEL_SECURE256,
.cipher_list = &cipher_priority_secure192,
.mac_list = &mac_priority_secure192,
.kx_list = &kx_priority_secure,
.sign_list = &sign_priority_secure192,
.group_list = &supported_groups_secure192,
.profile = GNUTLS_PROFILE_HIGH,
.sec_param = GNUTLS_SEC_PARAM_HIGH
},
{.name = LEVEL_SUITEB128,
.proto_list = &protocol_priority_suiteb,
.cipher_list = &cipher_priority_suiteb128,
.mac_list = &mac_priority_suiteb,
.kx_list = &kx_priority_suiteb,
.sign_list = &sign_priority_suiteb128,
.group_list = &supported_groups_suiteb128,
.profile = GNUTLS_PROFILE_SUITEB128,
.sec_param = GNUTLS_SEC_PARAM_HIGH
},
{.name = LEVEL_SUITEB192,
.proto_list = &protocol_priority_suiteb,
.cipher_list = &cipher_priority_suiteb192,
.mac_list = &mac_priority_suiteb,
.kx_list = &kx_priority_suiteb,
.sign_list = &sign_priority_suiteb192,
.group_list = &supported_groups_suiteb192,
.profile = GNUTLS_PROFILE_SUITEB192,
.sec_param = GNUTLS_SEC_PARAM_ULTRA
},
{.name = LEVEL_LEGACY,
.cipher_list = &cipher_priority_normal,
.mac_list = &mac_priority_normal,
.kx_list = &kx_priority_secure,
.sign_list = &sign_priority_default,
.group_list = &supported_groups_normal,
.sec_param = GNUTLS_SEC_PARAM_VERY_WEAK
},
{.name = LEVEL_PERFORMANCE,
.cipher_list = &cipher_priority_performance,
.mac_list = &mac_priority_normal,
.kx_list = &kx_priority_performance,
.sign_list = &sign_priority_default,
.group_list = &supported_groups_normal,
.profile = GNUTLS_PROFILE_LOW,
.sec_param = GNUTLS_SEC_PARAM_WEAK
},
{
.name = NULL,
}
};
#define SET_PROFILE(to_set) \
profile = GNUTLS_VFLAGS_TO_PROFILE(priority_cache->additional_verify_flags); \
if (profile == 0 || profile > to_set) { \
priority_cache->additional_verify_flags &= ~GNUTLS_VFLAGS_PROFILE_MASK; \
priority_cache->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(to_set); \
}
#define SET_LEVEL(to_set) \
if (priority_cache->level == 0 || (unsigned)priority_cache->level > (unsigned)to_set) \
priority_cache->level = to_set
static
int check_level(const char *level, gnutls_priority_t priority_cache,
int add)
{
bulk_rmadd_func *func;
unsigned profile = 0;
unsigned i;
int j;
const cipher_entry_st *centry;
if (add)
func = _add_priority;
else
func = _set_priority;
for (i=0;;i++) {
if (pgroups[i].name == NULL)
return 0;
if (strcasecmp(level, pgroups[i].name) == 0 ||
(pgroups[i].alias != NULL && strcasecmp(level, pgroups[i].alias) == 0)) {
if (pgroups[i].proto_list != NULL)
func(&priority_cache->protocol, *pgroups[i].proto_list);
func(&priority_cache->_cipher, *pgroups[i].cipher_list);
func(&priority_cache->_kx, *pgroups[i].kx_list);
func(&priority_cache->_mac, *pgroups[i].mac_list);
func(&priority_cache->_sign_algo, *pgroups[i].sign_list);
func(&priority_cache->_supported_ecc, *pgroups[i].group_list);
if (pgroups[i].profile != 0) {
SET_PROFILE(pgroups[i].profile); /* set certificate level */
}
SET_LEVEL(pgroups[i].sec_param); /* set DH params level */
priority_cache->no_tickets = pgroups[i].no_tickets;
if (priority_cache->have_cbc == 0) {
for (j=0;(*pgroups[i].cipher_list)[j]!=0;j++) {
centry = cipher_to_entry((*pgroups[i].cipher_list)[j]);
if (centry != NULL && centry->type == CIPHER_BLOCK) {
priority_cache->have_cbc = 1;
break;
}
}
}
return 1;
}
}
}
static void enable_compat(gnutls_priority_t c)
{
ENABLE_PRIO_COMPAT(c);
}
static void enable_server_key_usage_violations(gnutls_priority_t c)
{
c->allow_server_key_usage_violation = 1;
}
static void enable_dumbfw(gnutls_priority_t c)
{
c->_dumbfw = 1;
}
static void enable_no_extensions(gnutls_priority_t c)
{
c->no_extensions = 1;
}
static void enable_no_ext_master_secret(gnutls_priority_t c)
{
c->_no_ext_master_secret = 1;
}
static void enable_no_etm(gnutls_priority_t c)
{
c->_no_etm = 1;
}
static void enable_force_etm(gnutls_priority_t c)
{
c->force_etm = 1;
}
static void enable_no_tickets(gnutls_priority_t c)
{
c->no_tickets = 1;
}
static void disable_wildcards(gnutls_priority_t c)
{
c->additional_verify_flags |= GNUTLS_VERIFY_DO_NOT_ALLOW_WILDCARDS;
}
static void enable_profile_very_weak(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_VERY_WEAK);
c->level = GNUTLS_SEC_PARAM_VERY_WEAK;
}
static void enable_profile_low(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_LOW);
c->level = GNUTLS_SEC_PARAM_LOW;
}
static void enable_profile_legacy(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_LEGACY);
c->level = GNUTLS_SEC_PARAM_LEGACY;
}
static void enable_profile_high(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_HIGH);
c->level = GNUTLS_SEC_PARAM_HIGH;
}
static void enable_profile_ultra(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_ULTRA);
c->level = GNUTLS_SEC_PARAM_ULTRA;
}
static void enable_profile_medium(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_MEDIUM);
c->level = GNUTLS_SEC_PARAM_MEDIUM;
}
static void enable_profile_suiteb128(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_SUITEB128);
c->level = GNUTLS_SEC_PARAM_HIGH;
}
static void enable_profile_suiteb192(gnutls_priority_t c)
{
c->additional_verify_flags &= 0x00ffffff;
c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(GNUTLS_PROFILE_SUITEB192);
c->level = GNUTLS_SEC_PARAM_ULTRA;
}
static void enable_safe_renegotiation(gnutls_priority_t c)
{
c->sr = SR_SAFE;
}
static void enable_unsafe_renegotiation(gnutls_priority_t c)
{
c->sr = SR_UNSAFE;
}
static void enable_partial_safe_renegotiation(gnutls_priority_t c)
{
c->sr = SR_PARTIAL;
}
static void disable_safe_renegotiation(gnutls_priority_t c)
{
c->sr = SR_DISABLED;
}
static void enable_fallback_scsv(gnutls_priority_t c)
{
c->fallback = 1;
}
static void enable_latest_record_version(gnutls_priority_t c)
{
c->min_record_version = 0;
}
static void enable_ssl3_record_version(gnutls_priority_t c)
{
c->min_record_version = 1;
}
static void enable_verify_allow_rsa_md5(gnutls_priority_t c)
{
c->additional_verify_flags |=
GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5;
}
static void enable_verify_allow_sha1(gnutls_priority_t c)
{
c->additional_verify_flags |=
GNUTLS_VERIFY_ALLOW_SIGN_WITH_SHA1;
}
static void enable_verify_allow_broken(gnutls_priority_t c)
{
c->additional_verify_flags |=
GNUTLS_VERIFY_ALLOW_BROKEN;
}
static void disable_crl_checks(gnutls_priority_t c)
{
c->additional_verify_flags |=
GNUTLS_VERIFY_DISABLE_CRL_CHECKS;
}
static void enable_server_precedence(gnutls_priority_t c)
{
c->server_precedence = 1;
}
static void dummy_func(gnutls_priority_t c)
{
}
#include
static char *check_str(char *line, size_t line_size, const char *needle, size_t needle_size)
{
char *p;
unsigned n;
while (c_isspace(*line)) {
line++;
line_size--;
}
if (line[0] == '#' || needle_size >= line_size)
return NULL;
if (memcmp(line, needle, needle_size) == 0) {
p = &line[needle_size];
while (c_isspace(*p)) {
p++;
}
if (*p != '=') {
return NULL;
} else
p++;
while (c_isspace(*p)) {
p++;
}
n = strlen(p);
if (n > 1 && p[n-1] == '\n') {
n--;
p[n] = 0;
}
if (n > 1 && p[n-1] == '\r') {
n--;
p[n] = 0;
}
return p;
}
return NULL;
}
static const char *system_priority_file = SYSTEM_PRIORITY_FILE;
static char *system_priority_buf = NULL;
static size_t system_priority_buf_size = 0;
static time_t system_priority_last_mod = 0;
static void _gnutls_update_system_priorities(void)
{
#ifdef HAVE_FMEMOPEN
gnutls_datum_t data;
int ret;
struct stat sb;
if (stat(system_priority_file, &sb) < 0) {
_gnutls_debug_log("unable to access: %s: %d\n",
system_priority_file, errno);
return;
}
if (system_priority_buf != NULL &&
sb.st_mtime == system_priority_last_mod) {
_gnutls_debug_log("system priority %s has not changed\n",
system_priority_file);
return;
}
ret = gnutls_load_file(system_priority_file, &data);
if (ret < 0) {
_gnutls_debug_log("unable to load: %s: %d\n",
system_priority_file, ret);
return;
}
_gnutls_debug_log("cached system priority %s mtime %lld\n",
system_priority_file,
(unsigned long long)sb.st_mtime);
gnutls_free(system_priority_buf);
system_priority_buf = (char*)data.data;
system_priority_buf_size = data.size;
system_priority_last_mod = sb.st_mtime;
#endif
}
void _gnutls_load_system_priorities(void)
{
const char *p;
p = secure_getenv("GNUTLS_SYSTEM_PRIORITY_FILE");
if (p != NULL)
system_priority_file = p;
_gnutls_update_system_priorities();
}
void _gnutls_unload_system_priorities(void)
{
#ifdef HAVE_FMEMOPEN
gnutls_free(system_priority_buf);
#endif
system_priority_buf = NULL;
system_priority_buf_size = 0;
system_priority_last_mod = 0;
}
#define S(str) ((str!=NULL)?str:"")
/* Returns the new priorities if a priority string prefixed
* with '@' is provided, or just a copy of the provided
* priorities, appended with any additional present in
* the priorities string.
*
* The returned string must be released using gnutls_free().
*/
char *_gnutls_resolve_priorities(const char* priorities)
{
char *p = (char*)priorities;
char *additional = NULL;
char *ret = NULL;
char *ss, *ss_next, *line = NULL;
unsigned ss_len, ss_next_len;
int l;
FILE* fp = NULL;
size_t n, n2 = 0, line_size;
while (c_isspace(*p))
p++;
if (*p == '@') {
ss = p+1;
additional = strchr(ss, ':');
if (additional != NULL) {
additional++;
}
do {
ss_next = strchr(ss, ',');
if (ss_next != NULL) {
if (additional && ss_next > additional)
ss_next = NULL;
else
ss_next++;
}
if (ss_next) {
ss_len = ss_next - ss - 1;
ss_next_len = additional - ss_next - 1;
} else if (additional) {
ss_len = additional - ss - 1;
ss_next_len = 0;
} else {
ss_len = strlen(ss);
ss_next_len = 0;
}
#ifdef HAVE_FMEMOPEN
/* Always try to refresh the cached data, to
* allow it to be updated without restarting
* all applications
*/
_gnutls_update_system_priorities();
fp = fmemopen(system_priority_buf, system_priority_buf_size, "r");
#else
fp = fopen(system_priority_file, "r");
#endif
if (fp == NULL) {/* fail */
ret = NULL;
goto finish;
}
do {
l = getline(&line, &line_size, fp);
if (l > 0) {
p = check_str(line, line_size, ss, ss_len);
if (p != NULL)
break;
}
} while (l>0);
_gnutls_debug_log("resolved '%.*s' to '%s', next '%.*s'\n",
ss_len, ss, S(p), ss_next_len, S(ss_next));
ss = ss_next;
fclose(fp);
fp = NULL;
} while (ss && p == NULL);
if (p == NULL) {
_gnutls_debug_log("unable to resolve %s\n", priorities);
ret = NULL;
goto finish;
}
n = strlen(p);
if (additional)
n2 = strlen(additional);
ret = gnutls_malloc(n+n2+1+1);
if (ret == NULL) {
goto finish;
}
memcpy(ret, p, n);
if (additional != NULL) {
ret[n] = ':';
memcpy(&ret[n+1], additional, n2);
ret[n+n2+1] = 0;
} else {
ret[n] = 0;
}
} else {
return gnutls_strdup(p);
}
finish:
if (ret != NULL) {
_gnutls_debug_log("selected priority string: %s\n", ret);
}
free(line);
if (fp != NULL)
fclose(fp);
return ret;
}
static void add_ec(gnutls_priority_t priority_cache)
{
const gnutls_group_entry_st *ge;
unsigned i;
for (i = 0; i < priority_cache->_supported_ecc.algorithms; i++) {
ge = _gnutls_id_to_group(priority_cache->_supported_ecc.priority[i]);
if (ge != NULL && priority_cache->groups.size < sizeof(priority_cache->groups.entry)/sizeof(priority_cache->groups.entry[0])) {
/* do not add groups which do not correspond to enabled ciphersuites */
if (!ge->curve)
continue;
priority_cache->groups.entry[priority_cache->groups.size++] = ge;
}
}
}
static void add_dh(gnutls_priority_t priority_cache)
{
const gnutls_group_entry_st *ge;
unsigned i;
for (i = 0; i < priority_cache->_supported_ecc.algorithms; i++) {
ge = _gnutls_id_to_group(priority_cache->_supported_ecc.priority[i]);
if (ge != NULL && priority_cache->groups.size < sizeof(priority_cache->groups.entry)/sizeof(priority_cache->groups.entry[0])) {
/* do not add groups which do not correspond to enabled ciphersuites */
if (!ge->prime)
continue;
priority_cache->groups.entry[priority_cache->groups.size++] = ge;
priority_cache->groups.have_ffdhe = 1;
}
}
}
#define REMOVE_TLS13_IN_LOOP(vers, i) \
if (vers->tls13_sem) { \
for (j=i+1;jprotocol.algorithms;j++) \
priority_cache->protocol.priority[j-1] = priority_cache->protocol.priority[j]; \
priority_cache->protocol.algorithms--; \
i--; \
continue; \
}
static int set_ciphersuite_list(gnutls_priority_t priority_cache)
{
unsigned i, j, z;
const gnutls_cipher_suite_entry_st *ce;
const gnutls_sign_entry_st *se;
unsigned have_ec = 0;
unsigned have_dh = 0;
unsigned tls_sig_sem = 0;
const version_entry_st *tlsmax = NULL, *vers;
const version_entry_st *dtlsmax = NULL;
const version_entry_st *tlsmin = NULL;
const version_entry_st *dtlsmin = NULL;
unsigned have_tls13 = 0, have_srp = 0;
unsigned have_psk = 0, have_null = 0, have_rsa_psk = 0;
/* have_psk indicates that a PSK key exchange compatible
* with TLS1.3 is enabled. */
priority_cache->cs.size = 0;
priority_cache->sigalg.size = 0;
priority_cache->groups.size = 0;
priority_cache->groups.have_ffdhe = 0;
for (j=0;j_cipher.algorithms;j++) {
if (priority_cache->_cipher.priority[j] == GNUTLS_CIPHER_NULL) {
have_null = 1;
break;
}
}
for (i = 0; i < priority_cache->_kx.algorithms; i++) {
if (IS_SRP_KX(priority_cache->_kx.priority[i])) {
have_srp = 1;
} else if (_gnutls_kx_is_psk(priority_cache->_kx.priority[i])) {
if (priority_cache->_kx.priority[i] == GNUTLS_KX_RSA_PSK)
have_rsa_psk = 1;
else
have_psk = 1;
}
}
for (i = 0; i < priority_cache->protocol.algorithms; i++) {
vers = version_to_entry(priority_cache->protocol.priority[i]);
if (!vers)
continue;
/* if we have NULL ciphersuites, SRP, or RSA-PSK enabled remove TLS1.3+
* protocol versions; they cannot be negotiated under TLS1.3. */
if (have_null || have_srp || have_rsa_psk) {
REMOVE_TLS13_IN_LOOP(vers, i);
}
if (vers->transport == GNUTLS_STREAM) { /* TLS */
tls_sig_sem |= vers->tls_sig_sem;
if (vers->tls13_sem)
have_tls13 = 1;
if (tlsmax == NULL || vers->age > tlsmax->age)
tlsmax = vers;
if (tlsmin == NULL || vers->age < tlsmin->age)
tlsmin = vers;
} else { /* dtls */
tls_sig_sem |= vers->tls_sig_sem;
if (vers->tls13_sem)
have_tls13 = 1;
if (dtlsmax == NULL || vers->age > dtlsmax->age)
dtlsmax = vers;
if (dtlsmin == NULL || vers->age < dtlsmin->age)
dtlsmin = vers;
}
}
/* DTLS or TLS protocols must be present */
if ((!tlsmax || !tlsmin) && (!dtlsmax || !dtlsmin))
return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
priority_cache->have_psk = have_psk;
/* if we are have TLS1.3+ do not enable any key exchange algorithms,
* the protocol doesn't require any. */
if (tlsmin && tlsmin->tls13_sem && !have_psk) {
if (!dtlsmin || (dtlsmin && dtlsmin->tls13_sem))
priority_cache->_kx.algorithms = 0;
}
/* Add TLS 1.3 ciphersuites (no KX) */
for (j=0;j_cipher.algorithms;j++) {
for (z=0;z_mac.algorithms;z++) {
ce = cipher_suite_get(
0, priority_cache->_cipher.priority[j],
priority_cache->_mac.priority[z]);
if (ce != NULL && priority_cache->cs.size < MAX_CIPHERSUITE_SIZE) {
priority_cache->cs.entry[priority_cache->cs.size++] = ce;
}
}
}
for (i = 0; i < priority_cache->_kx.algorithms; i++) {
for (j=0;j_cipher.algorithms;j++) {
for (z=0;z_mac.algorithms;z++) {
ce = cipher_suite_get(
priority_cache->_kx.priority[i],
priority_cache->_cipher.priority[j],
priority_cache->_mac.priority[z]);
if (ce != NULL && priority_cache->cs.size < MAX_CIPHERSUITE_SIZE) {
priority_cache->cs.entry[priority_cache->cs.size++] = ce;
if (!have_ec && _gnutls_kx_is_ecc(ce->kx_algorithm)) {
have_ec = 1;
add_ec(priority_cache);
}
if (!have_dh && _gnutls_kx_is_dhe(ce->kx_algorithm)) {
have_dh = 1;
add_dh(priority_cache);
}
}
}
}
}
if (have_tls13 && (!have_ec || !have_dh)) {
/* scan groups to determine have_ec and have_dh */
for (i=0; i < priority_cache->_supported_ecc.algorithms; i++) {
const gnutls_group_entry_st *ge;
ge = _gnutls_id_to_group(priority_cache->_supported_ecc.priority[i]);
if (ge) {
if (ge->curve && !have_ec) {
add_ec(priority_cache);
have_ec = 1;
} else if (ge->prime && !have_dh) {
add_dh(priority_cache);
have_dh = 1;
}
if (have_dh && have_ec)
break;
}
}
}
for (i = 0; i < priority_cache->_sign_algo.algorithms; i++) {
se = _gnutls_sign_to_entry(priority_cache->_sign_algo.priority[i]);
if (se != NULL && priority_cache->sigalg.size < sizeof(priority_cache->sigalg.entry)/sizeof(priority_cache->sigalg.entry[0])) {
/* if the signature algorithm semantics are not compatible with
* the protocol's, then skip. */
if ((se->aid.tls_sem & tls_sig_sem) == 0)
continue;
priority_cache->sigalg.entry[priority_cache->sigalg.size++] = se;
}
}
_gnutls_debug_log("added %d protocols, %d ciphersuites, %d sig algos and %d groups into priority list\n",
priority_cache->protocol.algorithms,
priority_cache->cs.size, priority_cache->sigalg.size,
priority_cache->groups.size);
if (priority_cache->sigalg.size == 0) {
/* no signature algorithms; eliminate TLS 1.2 or DTLS 1.2 and later */
priority_st newp;
newp.algorithms = 0;
/* we need to eliminate TLS 1.2 or DTLS 1.2 and later protocols */
for (i = 0; i < priority_cache->protocol.algorithms; i++) {
if (priority_cache->protocol.priority[i] < GNUTLS_TLS1_2) {
newp.priority[newp.algorithms++] = priority_cache->protocol.priority[i];
} else if (priority_cache->protocol.priority[i] >= GNUTLS_DTLS_VERSION_MIN &&
priority_cache->protocol.priority[i] < GNUTLS_DTLS1_2) {
newp.priority[newp.algorithms++] = priority_cache->protocol.priority[i];
}
}
memcpy(&priority_cache->protocol, &newp, sizeof(newp));
}
if (unlikely(priority_cache->protocol.algorithms == 0))
return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
#ifndef ENABLE_SSL3
else if (unlikely(priority_cache->protocol.algorithms == 1 && priority_cache->protocol.priority[0] == GNUTLS_SSL3))
return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
#endif
if (unlikely(priority_cache->cs.size == 0))
return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
/* when TLS 1.3 is available we must have groups set */
if (unlikely(!have_psk && tlsmax && tlsmax->id >= GNUTLS_TLS1_3 && priority_cache->groups.size == 0)) {
for (i = 0; i < priority_cache->protocol.algorithms; i++) {
vers = version_to_entry(priority_cache->protocol.priority[i]);
if (!vers)
continue;
REMOVE_TLS13_IN_LOOP(vers, i);
}
}
return 0;
}
/**
* gnutls_priority_init2:
* @priority_cache: is a #gnutls_prioritity_t type.
* @priorities: is a string describing priorities (may be %NULL)
* @err_pos: In case of an error this will have the position in the string the error occurred
* @flags: zero or %GNUTLS_PRIORITY_INIT_DEF_APPEND
*
* Sets priorities for the ciphers, key exchange methods, and macs.
* The @priority_cache should be deinitialized
* using gnutls_priority_deinit().
*
* The #priorities option allows you to specify a colon
* separated list of the cipher priorities to enable.
* Some keywords are defined to provide quick access
* to common preferences.
*
* When @flags is set to %GNUTLS_PRIORITY_INIT_DEF_APPEND then the @priorities
* specified will be appended to the default options.
*
* Unless there is a special need, use the "NORMAL" keyword to
* apply a reasonable security level, or "NORMAL:%%COMPAT" for compatibility.
*
* "PERFORMANCE" means all the "secure" ciphersuites are enabled,
* limited to 128 bit ciphers and sorted by terms of speed
* performance.
*
* "LEGACY" the NORMAL settings for GnuTLS 3.2.x or earlier. There is
* no verification profile set, and the allowed DH primes are considered
* weak today.
*
* "NORMAL" means all "secure" ciphersuites. The 256-bit ciphers are
* included as a fallback only. The ciphers are sorted by security
* margin.
*
* "PFS" means all "secure" ciphersuites that support perfect forward secrecy.
* The 256-bit ciphers are included as a fallback only.
* The ciphers are sorted by security margin.
*
* "SECURE128" means all "secure" ciphersuites of security level 128-bit
* or more.
*
* "SECURE192" means all "secure" ciphersuites of security level 192-bit
* or more.
*
* "SUITEB128" means all the NSA SuiteB ciphersuites with security level
* of 128.
*
* "SUITEB192" means all the NSA SuiteB ciphersuites with security level
* of 192.
*
* "NONE" means nothing is enabled. This disables everything, including protocols.
*
* "@@KEYWORD1,KEYWORD2,..." The system administrator imposed settings.
* The provided keyword(s) will be expanded from a configuration-time
* provided file - default is: /etc/gnutls/default-priorities.
* Any attributes that follow it, will be appended to the expanded
* string. If multiple keywords are provided, separated by commas,
* then the first keyword that exists in the configuration file
* will be used. At least one of the keywords must exist, or this
* function will return an error. Typical usage would be to specify
* an application specified keyword first, followed by "SYSTEM" as
* a default fallback. e.g., "@LIBVIRT,SYSTEM:!-VERS-SSL3.0" will
* first try to find a config file entry matching "LIBVIRT", but if
* that does not exist will use the entry for "SYSTEM". If "SYSTEM"
* does not exist either, an error will be returned. In all cases,
* the SSL3.0 protocol will be disabled. The system priority file
* entries should be formatted as "KEYWORD=VALUE", e.g.,
* "SYSTEM=NORMAL:+ARCFOUR-128".
*
* Special keywords are "!", "-" and "+".
* "!" or "-" appended with an algorithm will remove this algorithm.
* "+" appended with an algorithm will add this algorithm.
*
* Check the GnuTLS manual section "Priority strings" for detailed
* information.
*
* Examples:
*
* "NONE:+VERS-TLS-ALL:+MAC-ALL:+RSA:+AES-128-CBC:+SIGN-ALL:+COMP-NULL"
*
* "NORMAL:+ARCFOUR-128" means normal ciphers plus ARCFOUR-128.
*
* "SECURE128:-VERS-SSL3.0" means that only secure ciphers are
* and enabled, SSL3.0 is disabled.
*
* "NONE:+VERS-TLS-ALL:+AES-128-CBC:+RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1",
*
* "NONE:+VERS-TLS-ALL:+AES-128-CBC:+ECDHE-RSA:+SHA1:+COMP-NULL:+SIGN-RSA-SHA1:+CURVE-SECP256R1",
*
* "SECURE256:+SECURE128",
*
* Note that "NORMAL:%%COMPAT" is the most compatible mode.
*
* A %NULL @priorities string indicates the default priorities to be
* used (this is available since GnuTLS 3.3.0).
*
* Returns: On syntax error %GNUTLS_E_INVALID_REQUEST is returned,
* %GNUTLS_E_SUCCESS on success, or an error code.
*
* Since: 3.6.3
**/
int
gnutls_priority_init2(gnutls_priority_t * priority_cache,
const char *priorities, const char **err_pos,
unsigned flags)
{
gnutls_buffer_st buf;
const char *ep;
int ret;
if (flags & GNUTLS_PRIORITY_INIT_DEF_APPEND) {
if (priorities == NULL)
return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
if (err_pos)
*err_pos = priorities;
_gnutls_buffer_init(&buf);
ret = _gnutls_buffer_append_str(&buf, _gnutls_default_priority_string);
if (ret < 0) {
_gnutls_buffer_clear(&buf);
return gnutls_assert_val(ret);
}
ret = _gnutls_buffer_append_str(&buf, ":");
if (ret < 0) {
_gnutls_buffer_clear(&buf);
return gnutls_assert_val(ret);
}
ret = _gnutls_buffer_append_str(&buf, priorities);
if (ret < 0) {
_gnutls_buffer_clear(&buf);
return gnutls_assert_val(ret);
}
ret = gnutls_priority_init(priority_cache, (const char*)buf.data, &ep);
if (ret < 0 && ep != (const char*)buf.data && ep != NULL) {
ptrdiff_t diff = (ptrdiff_t)ep-(ptrdiff_t)buf.data;
unsigned hlen = strlen(_gnutls_default_priority_string)+1;
if (err_pos && diff > hlen) {
*err_pos = priorities + diff - hlen;
}
}
_gnutls_buffer_clear(&buf);
return ret;
} else {
return gnutls_priority_init(priority_cache, priorities, err_pos);
}
}
/**
* gnutls_priority_init:
* @priority_cache: is a #gnutls_prioritity_t type.
* @priorities: is a string describing priorities (may be %NULL)
* @err_pos: In case of an error this will have the position in the string the error occurred
*
* For applications that do not modify their crypto settings per release, consider
* using gnutls_priority_init2() with %GNUTLS_PRIORITY_INIT_DEF_APPEND flag
* instead. We suggest to use centralized crypto settings handled by the GnuTLS
* library, and applications modifying the default settings to their needs.
*
* This function is identical to gnutls_priority_init2() with zero
* flags.
*
* A %NULL @priorities string indicates the default priorities to be
* used (this is available since GnuTLS 3.3.0).
*
* Returns: On syntax error %GNUTLS_E_INVALID_REQUEST is returned,
* %GNUTLS_E_SUCCESS on success, or an error code.
**/
int
gnutls_priority_init(gnutls_priority_t * priority_cache,
const char *priorities, const char **err_pos)
{
char *broken_list[MAX_ELEMENTS];
int broken_list_size = 0, i = 0, j;
char *darg = NULL;
unsigned ikeyword_set = 0;
int algo;
int ret;
rmadd_func *fn;
bulk_rmadd_func *bulk_fn;
bulk_rmadd_func *bulk_given_fn;
const cipher_entry_st *centry;
unsigned resolved_match = 1;
if (err_pos)
*err_pos = priorities;
*priority_cache =
gnutls_calloc(1, sizeof(struct gnutls_priority_st));
if (*priority_cache == NULL) {
gnutls_assert();
return GNUTLS_E_MEMORY_ERROR;
}
/* for now unsafe renegotiation is default on everyone. To be removed
* when we make it the default.
*/
(*priority_cache)->sr = SR_PARTIAL;
(*priority_cache)->min_record_version = 1;
gnutls_atomic_init(&(*priority_cache)->usage_cnt);
if (priorities == NULL) {
priorities = _gnutls_default_priority_string;
resolved_match = 0;
}
darg = _gnutls_resolve_priorities(priorities);
if (darg == NULL) {
gnutls_assert();
goto error;
}
if (strcmp(darg, priorities) != 0)
resolved_match = 0;
break_list(darg, broken_list, &broken_list_size);
/* This is our default set of protocol version, certificate types.
*/
if (strcasecmp(broken_list[0], LEVEL_NONE) != 0) {
_set_priority(&(*priority_cache)->protocol,
protocol_priority);
_set_priority(&(*priority_cache)->client_ctype,
cert_type_priority_default);
_set_priority(&(*priority_cache)->server_ctype,
cert_type_priority_default);
_set_priority(&(*priority_cache)->_sign_algo,
sign_priority_default);
_set_priority(&(*priority_cache)->_supported_ecc,
supported_groups_normal);
i = 0;
} else {
ikeyword_set = 1;
i = 1;
}
for (; i < broken_list_size; i++) {
if (check_level(broken_list[i], *priority_cache, ikeyword_set) != 0) {
ikeyword_set = 1;
continue;
} else if (broken_list[i][0] == '!'
|| broken_list[i][0] == '+'
|| broken_list[i][0] == '-') {
if (broken_list[i][0] == '+') {
fn = prio_add;
bulk_fn = _add_priority;
bulk_given_fn = _add_priority;
} else {
fn = prio_remove;
bulk_fn = _clear_priorities;
bulk_given_fn = _clear_given_priorities;
}
if (broken_list[i][0] == '+'
&& check_level(&broken_list[i][1],
*priority_cache, 1) != 0) {
continue;
} else if ((algo =
gnutls_mac_get_id(&broken_list[i][1]))
!= GNUTLS_MAC_UNKNOWN) {
fn(&(*priority_cache)->_mac, algo);
} else if ((centry = cipher_name_to_entry(&broken_list[i][1])) != NULL) {
if (_gnutls_cipher_exists(centry->id)) {
fn(&(*priority_cache)->_cipher, centry->id);
if (centry->type == CIPHER_BLOCK)
(*priority_cache)->have_cbc = 1;
}
} else if ((algo =
_gnutls_kx_get_id(&broken_list[i][1])) !=
GNUTLS_KX_UNKNOWN) {
if (algo != GNUTLS_KX_INVALID)
fn(&(*priority_cache)->_kx, algo);
} else if (strncasecmp
(&broken_list[i][1], "VERS-", 5) == 0) {
if (strncasecmp
(&broken_list[i][1], "VERS-TLS-ALL",
12) == 0) {
bulk_given_fn(&(*priority_cache)->
protocol,
stream_protocol_priority);
} else if (strncasecmp
(&broken_list[i][1],
"VERS-DTLS-ALL", 13) == 0) {
bulk_given_fn(&(*priority_cache)->
protocol,
(bulk_given_fn==_add_priority)?dtls_protocol_priority:dgram_protocol_priority);
} else if (strncasecmp
(&broken_list[i][1],
"VERS-ALL", 8) == 0) {
bulk_fn(&(*priority_cache)->
protocol,
protocol_priority);
} else {
if ((algo =
gnutls_protocol_get_id
(&broken_list[i][6])) !=
GNUTLS_VERSION_UNKNOWN)
fn(&(*priority_cache)->
protocol, algo);
else
goto error;
}
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "COMP-", 5) == 0) {
/* ignore all compression methods */
continue;
} /* now check if the element is something like -ALGO */
else if (strncasecmp
(&broken_list[i][1], "CURVE-", 6) == 0) {
if (strncasecmp
(&broken_list[i][1], "CURVE-ALL",
9) == 0) {
bulk_fn(&(*priority_cache)->
_supported_ecc,
supported_groups_normal);
} else {
if ((algo =
gnutls_ecc_curve_get_id
(&broken_list[i][7])) !=
GNUTLS_ECC_CURVE_INVALID)
fn(&(*priority_cache)->
_supported_ecc, algo);
else
goto error;
}
} else if (strncasecmp
(&broken_list[i][1], "GROUP-", 6) == 0) {
if (strncasecmp
(&broken_list[i][1], "GROUP-ALL",
9) == 0) {
bulk_fn(&(*priority_cache)->
_supported_ecc,
supported_groups_normal);
} else if (strncasecmp
(&broken_list[i][1], "GROUP-DH-ALL",
12) == 0) {
bulk_given_fn(&(*priority_cache)->
_supported_ecc,
_supported_groups_dh);
} else if (strncasecmp
(&broken_list[i][1], "GROUP-EC-ALL",
12) == 0) {
bulk_given_fn(&(*priority_cache)->
_supported_ecc,
_supported_groups_ecdh);
} else {
if ((algo =
gnutls_group_get_id
(&broken_list[i][7])) !=
GNUTLS_GROUP_INVALID)
fn(&(*priority_cache)->
_supported_ecc, algo);
else
goto error;
}
} else if (strncasecmp
(&broken_list[i][1], "CTYPE-", 6) == 0) { // Certificate types
if (strncasecmp(&broken_list[i][1], "CTYPE-ALL", 9) == 0)
{ // Symmetric cert types, all types allowed
bulk_fn(&(*priority_cache)->client_ctype, cert_type_priority_all);
bulk_fn(&(*priority_cache)->server_ctype, cert_type_priority_all);
} else if (strncasecmp(&broken_list[i][1], "CTYPE-CLI-", 10) == 0)
{ // Client certificate types
if (strncasecmp(&broken_list[i][1], "CTYPE-CLI-ALL", 13) == 0)
{ // All client cert types allowed
bulk_fn(&(*priority_cache)->client_ctype, cert_type_priority_all);
} else if ((algo = gnutls_certificate_type_get_id
(&broken_list[i][11])) != GNUTLS_CRT_UNKNOWN)
{ // Specific client cert type allowed
fn(&(*priority_cache)->client_ctype, algo);
} else goto error;
} else if (strncasecmp(&broken_list[i][1], "CTYPE-SRV-", 10) == 0)
{ // Server certificate types
if (strncasecmp(&broken_list[i][1], "CTYPE-SRV-ALL", 13) == 0)
{ // All server cert types allowed
bulk_fn(&(*priority_cache)->server_ctype, cert_type_priority_all);
} else if ((algo = gnutls_certificate_type_get_id
(&broken_list[i][11])) != GNUTLS_CRT_UNKNOWN)
{ // Specific server cert type allowed
fn(&(*priority_cache)->server_ctype, algo);
} else goto error;
} else { // Symmetric certificate type
if ((algo = gnutls_certificate_type_get_id
(&broken_list[i][7])) != GNUTLS_CRT_UNKNOWN)
{
fn(&(*priority_cache)->client_ctype, algo);
fn(&(*priority_cache)->server_ctype, algo);
} else goto error;
}
} else if (strncasecmp
(&broken_list[i][1], "SIGN-", 5) == 0) {
if (strncasecmp
(&broken_list[i][1], "SIGN-ALL",
8) == 0) {
bulk_fn(&(*priority_cache)->
_sign_algo,
sign_priority_default);
} else {
if ((algo =
gnutls_sign_get_id
(&broken_list[i][6])) !=
GNUTLS_SIGN_UNKNOWN)
fn(&(*priority_cache)->
_sign_algo, algo);
else
goto error;
}
} else if (strncasecmp
(&broken_list[i][1], "MAC-ALL", 7) == 0) {
bulk_fn(&(*priority_cache)->_mac,
mac_priority_normal);
} else if (strncasecmp
(&broken_list[i][1], "CIPHER-ALL",
10) == 0) {
bulk_fn(&(*priority_cache)->_cipher,
cipher_priority_normal);
} else if (strncasecmp
(&broken_list[i][1], "KX-ALL", 6) == 0) {
bulk_fn(&(*priority_cache)->_kx,
kx_priority_secure);
} else
goto error;
} else if (broken_list[i][0] == '%') {
const struct priority_options_st * o;
/* to add a new option modify
* priority_options.gperf */
o = in_word_set(&broken_list[i][1], strlen(&broken_list[i][1]));
if (o == NULL) {
goto error;
}
o->func(*priority_cache);
} else
goto error;
}
ret = set_ciphersuite_list(*priority_cache);
if (ret < 0) {
if (err_pos)
*err_pos = priorities;
goto error_cleanup;
}
gnutls_free(darg);
return 0;
error:
if (err_pos != NULL && i < broken_list_size && resolved_match) {
*err_pos = priorities;
for (j = 0; j < i; j++) {
(*err_pos) += strlen(broken_list[j]) + 1;
}
}
ret = GNUTLS_E_INVALID_REQUEST;
error_cleanup:
free(darg);
gnutls_priority_deinit(*priority_cache);
*priority_cache = NULL;
return ret;
}
/**
* gnutls_priority_deinit:
* @priority_cache: is a #gnutls_prioritity_t type.
*
* Deinitializes the priority cache.
**/
void gnutls_priority_deinit(gnutls_priority_t priority_cache)
{
if (priority_cache == NULL)
return;
/* Note that here we care about the following two cases:
* 1. Multiple sessions or different threads holding a reference + a global reference
* 2. One session holding a reference with a possible global reference
*
* As such, it will never be that two threads reach the
* zero state at the same time, unless the global reference
* is cleared too, which is invalid state.
*/
if (gnutls_atomic_val(&priority_cache->usage_cnt) == 0) {
gnutls_atomic_deinit(&priority_cache->usage_cnt);
gnutls_free(priority_cache);
return;
} else {
gnutls_atomic_decrement(&priority_cache->usage_cnt);
}
}
/**
* gnutls_priority_set_direct:
* @session: is a #gnutls_session_t type.
* @priorities: is a string describing priorities
* @err_pos: In case of an error this will have the position in the string the error occurred
*
* Sets the priorities to use on the ciphers, key exchange methods,
* and macs. This function avoids keeping a
* priority cache and is used to directly set string priorities to a
* TLS session. For documentation check the gnutls_priority_init().
*
* To use a reasonable default, consider using gnutls_set_default_priority(),
* or gnutls_set_default_priority_append() instead of this function.
*
* Returns: On syntax error %GNUTLS_E_INVALID_REQUEST is returned,
* %GNUTLS_E_SUCCESS on success, or an error code.
**/
int
gnutls_priority_set_direct(gnutls_session_t session,
const char *priorities, const char **err_pos)
{
gnutls_priority_t prio;
int ret;
ret = gnutls_priority_init(&prio, priorities, err_pos);
if (ret < 0) {
gnutls_assert();
return ret;
}
ret = gnutls_priority_set(session, prio);
if (ret < 0) {
gnutls_assert();
return ret;
}
/* ensure that the session holds the only reference for the struct */
gnutls_priority_deinit(prio);
return 0;
}
/* Breaks a list of "xxx", "yyy", to a character array, of
* MAX_COMMA_SEP_ELEMENTS size; Note that the given string is modified.
*/
static void
break_list(char *list,
char *broken_list[MAX_ELEMENTS], int *size)
{
char *p = list;
*size = 0;
do {
broken_list[*size] = p;
(*size)++;
p = strchr(p, ':');
if (p) {
*p = 0;
p++; /* move to next entry and skip white
* space.
*/
while (*p == ' ')
p++;
}
}
while (p != NULL && *size < MAX_ELEMENTS);
}
/**
* gnutls_set_default_priority:
* @session: is a #gnutls_session_t type.
*
* Sets the default priority on the ciphers, key exchange methods,
* and macs. This is the recommended method of
* setting the defaults, in order to promote consistency between applications
* using GnuTLS, and to allow GnuTLS using applications to update settings
* in par with the library. For client applications which require
* maximum compatibility consider calling gnutls_session_enable_compatibility_mode()
* after this function.
*
* For an application to specify additional options to priority string
* consider using gnutls_set_default_priority_append().
*
* To allow a user to override the defaults (e.g., when a user interface
* or configuration file is available), the functions
* gnutls_priority_set_direct() or gnutls_priority_set() can
* be used.
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code.
*
* Since: 2.1.4
**/
int gnutls_set_default_priority(gnutls_session_t session)
{
return gnutls_priority_set_direct(session, NULL, NULL);
}
/**
* gnutls_set_default_priority_append:
* @session: is a #gnutls_session_t type.
* @add_prio: is a string describing priorities to be appended to default
* @err_pos: In case of an error this will have the position in the string the error occurred
* @flags: must be zero
*
* Sets the default priority on the ciphers, key exchange methods,
* and macs with the additional options in @add_prio. This is the recommended method of
* setting the defaults when only few additional options are to be added. This promotes
* consistency between applications using GnuTLS, and allows GnuTLS using applications
* to update settings in par with the library.
*
* The @add_prio string should start as a normal priority string, e.g.,
* '-VERS-TLS-ALL:+VERS-TLS1.3:%%COMPAT' or '%%FORCE_ETM'. That is, it must not start
* with ':'.
*
* To allow a user to override the defaults (e.g., when a user interface
* or configuration file is available), the functions
* gnutls_priority_set_direct() or gnutls_priority_set() can
* be used.
*
* Returns: %GNUTLS_E_SUCCESS on success, or an error code.
*
* Since: 3.6.3
**/
int gnutls_set_default_priority_append(gnutls_session_t session,
const char *add_prio,
const char **err_pos,
unsigned flags)
{
gnutls_priority_t prio;
int ret;
ret = gnutls_priority_init2(&prio, add_prio, err_pos, GNUTLS_PRIORITY_INIT_DEF_APPEND);
if (ret < 0) {
gnutls_assert();
return ret;
}
ret = gnutls_priority_set(session, prio);
if (ret < 0) {
gnutls_assert();
return ret;
}
/* ensure that the session holds the only reference for the struct */
gnutls_priority_deinit(prio);
return 0;
}
/**
* gnutls_priority_ecc_curve_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available elliptic curves in the priority
* structure.
*
* Deprecated: This function has been replaced by
* gnutls_priority_group_list() since 3.6.0.
*
* Returns: the number of items, or an error code.
*
* Since: 3.0
**/
int
gnutls_priority_ecc_curve_list(gnutls_priority_t pcache,
const unsigned int **list)
{
unsigned i;
if (pcache->_supported_ecc.algorithms == 0)
return 0;
*list = pcache->_supported_ecc.priority;
/* to ensure we don't confuse the caller, we do not include
* any FFDHE groups. This may return an incomplete list. */
for (i=0;i_supported_ecc.algorithms;i++)
if (pcache->_supported_ecc.priority[i] > GNUTLS_ECC_CURVE_MAX)
return i;
return pcache->_supported_ecc.algorithms;
}
/**
* gnutls_priority_group_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available groups in the priority
* structure.
*
* Returns: the number of items, or an error code.
*
* Since: 3.6.0
**/
int
gnutls_priority_group_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->_supported_ecc.algorithms == 0)
return 0;
*list = pcache->_supported_ecc.priority;
return pcache->_supported_ecc.algorithms;
}
/**
* gnutls_priority_kx_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available key exchange methods in the priority
* structure.
*
* Returns: the number of items, or an error code.
* Since: 3.2.3
**/
int
gnutls_priority_kx_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->_kx.algorithms == 0)
return 0;
*list = pcache->_kx.priority;
return pcache->_kx.algorithms;
}
/**
* gnutls_priority_cipher_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available ciphers in the priority
* structure.
*
* Returns: the number of items, or an error code.
* Since: 3.2.3
**/
int
gnutls_priority_cipher_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->_cipher.algorithms == 0)
return 0;
*list = pcache->_cipher.priority;
return pcache->_cipher.algorithms;
}
/**
* gnutls_priority_mac_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available MAC algorithms in the priority
* structure.
*
* Returns: the number of items, or an error code.
* Since: 3.2.3
**/
int
gnutls_priority_mac_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->_mac.algorithms == 0)
return 0;
*list = pcache->_mac.priority;
return pcache->_mac.algorithms;
}
/**
* gnutls_priority_compression_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available compression method in the priority
* structure.
*
* Returns: the number of methods, or an error code.
* Since: 3.0
**/
int
gnutls_priority_compression_list(gnutls_priority_t pcache,
const unsigned int **list)
{
static const unsigned int priority[1] = {GNUTLS_COMP_NULL};
*list = priority;
return 1;
}
/**
* gnutls_priority_protocol_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available TLS version numbers in the priority
* structure.
*
* Returns: the number of protocols, or an error code.
* Since: 3.0
**/
int
gnutls_priority_protocol_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->protocol.algorithms == 0)
return 0;
*list = pcache->protocol.priority;
return pcache->protocol.algorithms;
}
/**
* gnutls_priority_sign_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available signature algorithms in the priority
* structure.
*
* Returns: the number of algorithms, or an error code.
* Since: 3.0
**/
int
gnutls_priority_sign_list(gnutls_priority_t pcache,
const unsigned int **list)
{
if (pcache->_sign_algo.algorithms == 0)
return 0;
*list = pcache->_sign_algo.priority;
return pcache->_sign_algo.algorithms;
}
/**
* gnutls_priority_certificate_type_list:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list
*
* Get a list of available certificate types in the priority
* structure.
*
* As of version 3.6.4 this function is an alias for
* gnutls_priority_certificate_type_list2 with the target parameter
* set to:
* - GNUTLS_CTYPE_SERVER, if the %SERVER_PRECEDENCE option is set
* - GNUTLS_CTYPE_CLIENT, otherwise.
*
* Returns: the number of certificate types, or an error code.
* Since: 3.0
**/
int
gnutls_priority_certificate_type_list(gnutls_priority_t pcache,
const unsigned int **list)
{
gnutls_ctype_target_t target =
pcache->server_precedence ? GNUTLS_CTYPE_SERVER : GNUTLS_CTYPE_CLIENT;
return gnutls_priority_certificate_type_list2(pcache, list, target);
}
/**
* gnutls_priority_certificate_type_list2:
* @pcache: is a #gnutls_prioritity_t type.
* @list: will point to an integer list.
* @target: is a #gnutls_ctype_target_t type. Valid arguments are
* GNUTLS_CTYPE_CLIENT and GNUTLS_CTYPE_SERVER
*
* Get a list of available certificate types for the given target
* in the priority structure.
*
* Returns: the number of certificate types, or an error code.
*
* Since: 3.6.4
**/
int
gnutls_priority_certificate_type_list2(gnutls_priority_t pcache,
const unsigned int **list, gnutls_ctype_target_t target)
{
switch (target) {
case GNUTLS_CTYPE_CLIENT:
if(pcache->client_ctype.algorithms > 0) {
*list = pcache->client_ctype.priority;
return pcache->client_ctype.algorithms;
}
break;
case GNUTLS_CTYPE_SERVER:
if(pcache->server_ctype.algorithms > 0) {
*list = pcache->server_ctype.priority;
return pcache->server_ctype.algorithms;
}
break;
default:
// Invalid target given
gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
}
// Found a matching target but non of them had any ctypes set
return 0;
}
/**
* gnutls_priority_string_list:
* @iter: an integer counter starting from zero
* @flags: one of %GNUTLS_PRIORITY_LIST_INIT_KEYWORDS, %GNUTLS_PRIORITY_LIST_SPECIAL
*
* Can be used to iterate all available priority strings.
* Due to internal implementation details, there are cases where this
* function can return the empty string. In that case that string should be ignored.
* When no strings are available it returns %NULL.
*
* Returns: a priority string
* Since: 3.4.0
**/
const char *
gnutls_priority_string_list(unsigned iter, unsigned int flags)
{
if (flags & GNUTLS_PRIORITY_LIST_INIT_KEYWORDS) {
if (iter >= (sizeof(pgroups)/sizeof(pgroups[0]))-1)
return NULL;
return pgroups[iter].name;
} else if (flags & GNUTLS_PRIORITY_LIST_SPECIAL) {
if (iter >= (sizeof(wordlist)/sizeof(wordlist[0]))-1)
return NULL;
return wordlist[iter].name;
}
return NULL;
}