/src/gnutls/lib/priority.c

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/*
 * Copyright (C) 2004-2015 Free Software Foundation, Inc.
 * Copyright (C) 2015-2019 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 <https://www.gnu.org/licenses/>
 *
 */

/* Here lies the code of the gnutls_*_set_priority() functions.
 */

#include "gnutls_int.h"
#include "algorithms.h"
#include "errors.h"
#include <num.h>
#include <gnutls/x509.h>
#include <c-ctype.h>
#include <hello_ext.h>
#include <c-strcase.h>
#include "fips.h"
#include "errno.h"
#include "ext/srp.h"
#include <gnutls/gnutls.h>
#include "profiles.h"
#include "c-strcase.h"
#include "inih/ini.h"
#include "locks.h"
#include "profiles.h"
#include "name_val_array.h"

#define MAX_ELEMENTS GNUTLS_MAX_ALGORITHM_NUM

#define ENABLE_PROFILE(c, profile) do { \
  c->additional_verify_flags &= 0x00ffffff; \
  c->additional_verify_flags |= GNUTLS_PROFILE_TO_VFLAGS(profile); \
  c->level = _gnutls_profile_to_sec_level(profile); \
  } while(0)

/* This function is used by the test suite */
char *_gnutls_resolve_priorities(const char *priorities);

/* This variable points to either a constant value (DEFAULT_PRIORITY_STRING or
 * externally assigned) or heap-allocated
 * system_wide_config.default_priority_string. We can't move this to the
 * system_wide_config struct, because this variable is part of (private) ABI
 * exported for testing.
 */
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->num_priorities = num;

  for (i = 0; i < num; i++) {
    st->priorities[i] = list[i];
  }

  return;
}

inline static void _add_priority(priority_st * st, const int *list)
{
  int num, i, j, init;

  init = i = st->num_priorities;

  for (num = 0; list[num] != 0; ++num) {
    if (i + 1 > MAX_ALGOS) {
      return;
    }

    for (j = 0; j < init; j++) {
      if (st->priorities[j] == (unsigned)list[num]) {
        break;
      }
    }

    if (j == init) {
      st->priorities[i++] = list[num];
      st->num_priorities++;
    }
  }

  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,  /* RFC 8422 */
  GNUTLS_GROUP_X448,  /* RFC 8422 */
  0
};

static const int _supported_groups_gost[] = {
#ifdef ENABLE_GOST
  GNUTLS_GROUP_GC256A,
  GNUTLS_GROUP_GC256B,
  GNUTLS_GROUP_GC256C,
  GNUTLS_GROUP_GC256D,
  GNUTLS_GROUP_GC512A,
  GNUTLS_GROUP_GC512B,
  GNUTLS_GROUP_GC512C,
#endif
  0
};

static const int _supported_groups_normal[] = {
  GNUTLS_GROUP_SECP256R1,
  GNUTLS_GROUP_SECP384R1,
  GNUTLS_GROUP_SECP521R1,
  GNUTLS_GROUP_X25519,  /* RFC 8422 */
  GNUTLS_GROUP_X448,  /* RFC 8422 */

  /* 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,  /* RFC 8422 */
  GNUTLS_GROUP_X448,  /* RFC 8422 */
  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 _kx_priority_gost[] = {
#ifdef ENABLE_GOST
  GNUTLS_KX_VKO_GOST_12,
#endif
  0,
};

static const int *kx_priority_gost = _kx_priority_gost;

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_EDDSA_ED448,

  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_EDDSA_ED448,

  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_EDDSA_ED448,
  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 _sign_priority_gost[] = {
#ifdef ENABLE_GOST
  GNUTLS_SIGN_GOST_256,
  GNUTLS_SIGN_GOST_512,
#endif
  0
};

static const int *sign_priority_gost = _sign_priority_gost;

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;

static const int _cipher_priority_gost[] = {
#ifdef ENABLE_GOST
  GNUTLS_CIPHER_GOST28147_TC26Z_CNT,
#endif
  0
};

static const int *cipher_priority_gost = _cipher_priority_gost;

static const int _mac_priority_gost[] = {
#ifdef ENABLE_GOST
  GNUTLS_MAC_GOST28147_TC26Z_IMIT,
#endif
  0
};

static const int *mac_priority_gost = _mac_priority_gost;

/* 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->num_priorities; i++) {
    if (priority_list->priorities[i] == algo) {
      priority_list->num_priorities--;
      if ((priority_list->num_priorities - i) > 0)
        memmove(&priority_list->priorities[i],
          &priority_list->priorities[i + 1],
          (priority_list->num_priorities -
           i) *
          sizeof(priority_list->priorities[0]));
      priority_list->priorities[priority_list->
              num_priorities] = 0;
      break;
    }
  }

  return;
}

static void prio_add(priority_st * priority_list, unsigned int algo)
{
  unsigned int i, l = priority_list->num_priorities;

  if (l >= MAX_ALGOS)
    return;   /* can't add it anyway */

  for (i = 0; i < l; ++i) {
    if (algo == priority_list->priorities[i])
      return; /* if it exists */
  }

  priority_list->priorities[l] = algo;
  priority_list->num_priorities++;

  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. Note that this function is expected to be called once
 * per session; when called multiple times (e.g., before a re-handshake,
 * the caller should make sure that any new settings are not incompatible
 * with the original session).
 *
 * Returns: %GNUTLS_E_SUCCESS on success, or an error code on error.
 **/
int gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority)
{
  int ret;

  if (priority == NULL || priority->protocol.num_priorities == 0 ||
      priority->cs.size == 0)
    return gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);

  /* set the current version to the first in the chain, if this is
   * the call before the initial handshake. During a re-handshake
   * we do not set the version to avoid overriding the currently
   * negotiated version. */
  if (!session->internals.handshake_in_progress &&
      !session->internals.initial_negotiation_completed) {
    ret = _gnutls_set_current_version(session,
              priority->
              protocol.priorities[0]);
    if (ret < 0)
      return gnutls_assert_val(ret);
  }

  /* At this point the provided priorities passed the sanity tests */

  if (session->internals.priorities)
    gnutls_priority_deinit(session->internals.priorities);

  gnutls_atomic_increment(&priority->usage_cnt);
  session->internals.priorities = priority;

  if (priority->no_tickets != 0) {
    session->internals.flags |= GNUTLS_NO_TICKETS;
  }

  if (priority->no_tickets_tls12 != 0) {
    /* when PFS is explicitly requested, disable session tickets for TLS 1.2 */
    session->internals.flags |= GNUTLS_NO_TICKETS_TLS12;
  }

  if (priority->no_status_request)
    session->internals.flags |= GNUTLS_NO_STATUS_REQUEST;

  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(allow_small_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"
#define LEVEL_SYSTEM "SYSTEM"

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;
  bool no_tickets_tls12;
};

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_tls12 = 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 (c_strcasecmp(level, pgroups[i].name) == 0 ||
        (pgroups[i].alias != NULL
         && c_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;
      priority_cache->no_tickets_tls12 =
          pgroups[i].no_tickets_tls12;
      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_allow_small_records(gnutls_priority_t c)
{
  c->_allow_small_records = 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_status_request(gnutls_priority_t c)
{
  c->no_status_request = 1;
}

static void enable_no_ext_master_secret(gnutls_priority_t c)
{
  c->_no_ext_master_secret = 1;
}

static void enable_force_ext_master_secret(gnutls_priority_t c)
{
  c->force_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 enable_no_tickets_tls12(gnutls_priority_t c)
{
  c->no_tickets_tls12 = 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)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_VERY_WEAK);
}

static void enable_profile_low(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_LOW);
}

static void enable_profile_legacy(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_LEGACY);
}

static void enable_profile_medium(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_MEDIUM);
}

static void enable_profile_high(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_HIGH);
}

static void enable_profile_ultra(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_ULTRA);
}

static void enable_profile_future(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_FUTURE);
}

static void enable_profile_suiteb128(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_SUITEB128);
}

static void enable_profile_suiteb192(gnutls_priority_t c)
{
  ENABLE_PROFILE(c, GNUTLS_PROFILE_SUITEB128);
}

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 disable_tls13_compat_mode(gnutls_priority_t c)
{
  c->tls13_compat_mode = false;
}

static void dummy_func(gnutls_priority_t c)
{
}

#include <priority_options.h>

struct cfg {
  bool allowlisting;
  bool ktls_enabled;

  name_val_array_t priority_strings;
  char *priority_string;
  char *default_priority_string;
  gnutls_certificate_verification_profiles_t verification_profile;

  gnutls_cipher_algorithm_t ciphers[MAX_ALGOS + 1];
  gnutls_mac_algorithm_t macs[MAX_ALGOS + 1];
  gnutls_group_t groups[MAX_ALGOS + 1];
  gnutls_kx_algorithm_t kxs[MAX_ALGOS + 1];
  gnutls_sign_algorithm_t sigs[MAX_ALGOS + 1];
  gnutls_protocol_t versions[MAX_ALGOS + 1];

  gnutls_digest_algorithm_t hashes[MAX_ALGOS + 1];
  gnutls_ecc_curve_t ecc_curves[MAX_ALGOS + 1];
  gnutls_sign_algorithm_t sigs_for_cert[MAX_ALGOS + 1];
};

static inline void cfg_deinit(struct cfg *cfg)
{
  if (cfg->priority_strings) {
    _name_val_array_clear(&cfg->priority_strings);
  }
  gnutls_free(cfg->priority_string);
  gnutls_free(cfg->default_priority_string);
}

/* Lock for reading and writing system_wide_config */
GNUTLS_RWLOCK(system_wide_config_rwlock);
static struct cfg system_wide_config;

static unsigned fail_on_invalid_config = 0;
static const char *system_priority_file = SYSTEM_PRIORITY_FILE;
static time_t system_priority_last_mod = 0;
static unsigned system_priority_file_loaded = 0;

#define GLOBAL_SECTION "global"
#define CUSTOM_PRIORITY_SECTION "priorities"
#define OVERRIDES_SECTION "overrides"
#define MAX_ALGO_NAME 2048

bool _gnutls_allowlisting_mode(void)
{
  return system_wide_config.allowlisting;
}

static void _clear_default_system_priority(void)
{
  gnutls_free(system_wide_config.default_priority_string);
  system_wide_config.default_priority_string = NULL;

  _gnutls_default_priority_string = DEFAULT_PRIORITY_STRING;
}

gnutls_certificate_verification_profiles_t
_gnutls_get_system_wide_verification_profile(void)
{
  return system_wide_config.verification_profile;
}

/* removes spaces */
static char *clear_spaces(const char *str, char out[MAX_ALGO_NAME])
{
  const char *p = str;
  unsigned i = 0;

  while (c_isspace(*p))
    p++;

  while (!c_isspace(*p) && *p != 0) {
    out[i++] = *p;
    p++;

    if (i >= MAX_ALGO_NAME - 1)
      break;
  }
  out[i] = 0;
  return out;
}

struct ini_ctx {
  struct cfg cfg;

  gnutls_digest_algorithm_t *hashes;
  size_t hashes_size;
  gnutls_sign_algorithm_t *sigs;
  size_t sigs_size;
  gnutls_sign_algorithm_t *sigs_for_cert;
  size_t sigs_for_cert_size;
  gnutls_protocol_t *versions;
  size_t versions_size;
  gnutls_ecc_curve_t *curves;
  size_t curves_size;
};

static inline void ini_ctx_deinit(struct ini_ctx *ctx)
{
  cfg_deinit(&ctx->cfg);
  gnutls_free(ctx->hashes);
  gnutls_free(ctx->sigs);
  gnutls_free(ctx->sigs_for_cert);
  gnutls_free(ctx->versions);
  gnutls_free(ctx->curves);
}

static inline void cfg_steal(struct cfg *dst, struct cfg *src)
{
  dst->verification_profile = src->verification_profile;

  dst->priority_strings = src->priority_strings;
  src->priority_strings = NULL;

  dst->priority_string = src->priority_string;
  src->priority_string = NULL;

  dst->default_priority_string = src->default_priority_string;
  src->default_priority_string = NULL;

  dst->allowlisting = src->allowlisting;
  dst->ktls_enabled = src->ktls_enabled;
  memcpy(dst->ciphers, src->ciphers, sizeof(src->ciphers));
  memcpy(dst->macs, src->macs, sizeof(src->macs));
  memcpy(dst->groups, src->groups, sizeof(src->groups));
  memcpy(dst->kxs, src->kxs, sizeof(src->kxs));
  memcpy(dst->hashes, src->hashes, sizeof(src->hashes));
  memcpy(dst->ecc_curves, src->ecc_curves, sizeof(src->ecc_curves));
  memcpy(dst->sigs, src->sigs, sizeof(src->sigs));
  memcpy(dst->sigs_for_cert, src->sigs_for_cert,
         sizeof(src->sigs_for_cert));
}

/*
 * synchronizing changes from struct cfg to global `lib/algorithms` arrays
 */

/* global side-effect! modifies `flags` in `hash_algorithms[]` */
static inline int /* allowlisting-only */ _cfg_hashes_remark(struct cfg *cfg)
{
  size_t i;
  _gnutls_digest_mark_insecure_all();
  for (i = 0; cfg->hashes[i] != 0; i++) {
    int ret = _gnutls_digest_set_secure(cfg->hashes[i], 1);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  }
  return 0;
}

/* global side-effect! modifies `flags` in `sign_algorithms[]` */
static inline int /* allowlisting-only */ _cfg_sigs_remark(struct cfg *cfg)
{
  size_t i;
  _gnutls_sign_mark_insecure_all(_INSECURE);
  for (i = 0; cfg->sigs[i] != 0; i++) {
    int ret = _gnutls_sign_set_secure(cfg->sigs[i],
              _INSECURE_FOR_CERTS);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  }
  for (i = 0; cfg->sigs_for_cert[i] != 0; i++) {
    int ret = _gnutls_sign_set_secure(cfg->sigs_for_cert[i],
              _SECURE);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  }
  return 0;
}

/* global side-effect! modifies `supported` in `sup_versions[]` */
static inline int /* allowlisting-only */ _cfg_versions_remark(struct cfg *cfg)
{
  size_t i;
  _gnutls_version_mark_disabled_all();
  for (i = 0; cfg->versions[i] != 0; i++) {
    int ret = _gnutls_protocol_set_enabled(cfg->versions[i], 1);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  }
  return 0;
}

/* global side-effect! modifies `supported` in `ecc_curves[]` */
static inline int /* allowlisting-only */ _cfg_ecc_curves_remark(struct cfg
                 *cfg)
{
  size_t i;
  _gnutls_ecc_curve_mark_disabled_all();
  for (i = 0; cfg->ecc_curves[i] != 0; i++) {
    int ret = _gnutls_ecc_curve_set_enabled(cfg->ecc_curves[i], 1);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  }
  return 0;
}

/*
 * setting arrays of struct cfg: from other arrays
 */

static inline int /* allowlisting-only */ cfg_hashes_set_array(struct cfg *cfg,
                     gnutls_digest_algorithm_t
                     * src,
                     size_t len)
{
  if (unlikely(len >= MAX_ALGOS)) {
    return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR);
  }
  if (len) {
    memcpy(cfg->hashes,
           src, sizeof(gnutls_digest_algorithm_t) * len);
  }
  cfg->hashes[len] = 0;
  return _cfg_hashes_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_sigs_set_arrays(struct cfg *cfg,
                    gnutls_sign_algorithm_t
                    * src, size_t len,
                    gnutls_sign_algorithm_t
                    * src_for_cert,
                    size_t
                    len_for_cert)
{
  if (unlikely(len >= MAX_ALGOS)) {
    return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR);
  }
  if (unlikely(len_for_cert >= MAX_ALGOS)) {
    return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR);
  }
  if (len) {
    memcpy(cfg->sigs, src, sizeof(gnutls_sign_algorithm_t) * len);
  }
  if (len_for_cert) {
    memcpy(cfg->sigs_for_cert, src_for_cert,
           sizeof(gnutls_sign_algorithm_t) * len_for_cert);
  }
  cfg->sigs[len] = 0;
  cfg->sigs_for_cert[len_for_cert] = 0;
  return _cfg_sigs_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_versions_set_array(struct cfg
                 *cfg,
                 gnutls_protocol_t
                 * src,
                 size_t len)
{
  if (unlikely(len >= MAX_ALGOS)) {
    return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR);
  }
  if (len) {
    memcpy(cfg->versions, src, sizeof(gnutls_protocol_t) * len);
  }
  cfg->versions[len] = 0;
  return _cfg_versions_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_ecc_curves_set_array(struct cfg
                   *cfg,
                   gnutls_ecc_curve_t
                   * src,
                   size_t len)
{
  if (unlikely(len >= MAX_ALGOS)) {
    return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR);
  }
  if (len) {
    memcpy(cfg->ecc_curves, src, sizeof(gnutls_ecc_curve_t) * len);
  }
  cfg->ecc_curves[len] = 0;
  return _cfg_ecc_curves_remark(cfg);
}

/*
 * appending to arrays of struct cfg
 */

/* polymorphic way to DRY this operation. other possible approaches:
 * 1. just unmacro (long)
 * 2. cast to ints and write a function operating on ints
 *    (hacky, every call is +4 lines, needs a portable static assert)
 * 3. macro whole functions, not just this operation (harder to find/read)
 */
#define APPEND_TO_NULL_TERMINATED_ARRAY(dst, element) \
  do { \
    size_t i; \
    for (i = 0; dst[i] != 0; i++) { \
      if (dst[i] == element) { \
        return 0; \
      } \
    } \
    if (unlikely(i >= MAX_ALGOS)) { \
      return gnutls_assert_val(GNUTLS_A_INTERNAL_ERROR); \
    } \
    dst[i] = element; \
    dst[i + 1] = 0; \
  } while (0)

static inline int /* allowlisting-only */ cfg_hashes_add(struct cfg *cfg,
               gnutls_digest_algorithm_t
               dig)
{
  _gnutls_debug_log("cfg: enabling digest algorithm %s\n",
        gnutls_digest_get_name(dig));
  APPEND_TO_NULL_TERMINATED_ARRAY(cfg->hashes, dig);
  return _cfg_hashes_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_sigs_add(struct cfg *cfg,
                   gnutls_sign_algorithm_t
                   sig)
{
  _gnutls_debug_log("cfg: enabling signature algorithm "
        "(for non-certificate usage) "
        "%s\n", gnutls_sign_get_name(sig));
  APPEND_TO_NULL_TERMINATED_ARRAY(cfg->sigs, sig);
  return _cfg_sigs_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_sigs_for_cert_add(struct cfg *cfg,
                gnutls_sign_algorithm_t
                sig)
{
  _gnutls_debug_log("cfg: enabling signature algorithm"
        "(for certificate usage) "
        "%s\n", gnutls_sign_get_name(sig));
  APPEND_TO_NULL_TERMINATED_ARRAY(cfg->sigs_for_cert, sig);
  return _cfg_sigs_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_versions_add(struct cfg *cfg,
                 gnutls_protocol_t
                 prot)
{
  _gnutls_debug_log("cfg: enabling version %s\n",
        gnutls_protocol_get_name(prot));
  APPEND_TO_NULL_TERMINATED_ARRAY(cfg->versions, prot);
  return _cfg_versions_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_ecc_curves_add(struct cfg *cfg,
                   gnutls_ecc_curve_t
                   curve)
{
  _gnutls_debug_log("cfg: enabling curve %s\n",
        gnutls_ecc_curve_get_name(curve));
  APPEND_TO_NULL_TERMINATED_ARRAY(cfg->ecc_curves, curve);
  return _cfg_ecc_curves_remark(cfg);
}

#undef APPEND_TO_NULL_TERMINATED_ARRAY

/*
 * removing from arrays of struct cfg
 */

/* polymorphic way to DRY this removal, see APPEND_TO_NULL_TERMINATED_ARRAY */
#define REMOVE_FROM_NULL_TERMINATED_ARRAY(dst, element) \
  do { \
    size_t i, j; \
    for (i = 0; dst[i] != 0; i++) { \
      if (dst[i] == element) { \
        for (j = i; dst[j] != 0; j++) { \
          dst[j] = dst[j + 1]; \
        } \
      } \
    } \
  } while (0)

static inline int /* allowlisting-only */ cfg_hashes_remove(struct cfg *cfg,
                  gnutls_digest_algorithm_t
                  dig)
{
  _gnutls_debug_log("cfg: disabling digest algorithm %s\n",
        gnutls_digest_get_name(dig));
  REMOVE_FROM_NULL_TERMINATED_ARRAY(cfg->hashes, dig);
  return _cfg_hashes_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_sigs_remove(struct cfg *cfg,
                gnutls_sign_algorithm_t
                sig)
{
  _gnutls_debug_log("cfg: disabling signature algorithm "
        "(for non-certificate usage) "
        "%s\n", gnutls_sign_get_name(sig));
  REMOVE_FROM_NULL_TERMINATED_ARRAY(cfg->sigs, sig);
  return _cfg_sigs_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_sigs_for_cert_remove(struct cfg
                   *cfg,
                   gnutls_sign_algorithm_t
                   sig)
{
  _gnutls_debug_log("cfg: disabling signature algorithm"
        "(for certificate usage) "
        "%s\n", gnutls_sign_get_name(sig));
  REMOVE_FROM_NULL_TERMINATED_ARRAY(cfg->sigs_for_cert, sig);
  return _cfg_sigs_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_versions_remove(struct cfg *cfg,
                    gnutls_protocol_t
                    prot)
{
  _gnutls_debug_log("cfg: disabling version %s\n",
        gnutls_protocol_get_name(prot));
  REMOVE_FROM_NULL_TERMINATED_ARRAY(cfg->versions, prot);
  return _cfg_versions_remark(cfg);
}

static inline int /* allowlisting-only */ cfg_ecc_curves_remove(struct cfg *cfg,
                gnutls_ecc_curve_t
                curve)
{
  _gnutls_debug_log("cfg: disabling curve %s\n",
        gnutls_ecc_curve_get_name(curve));
  REMOVE_FROM_NULL_TERMINATED_ARRAY(cfg->ecc_curves, curve);
  return _cfg_ecc_curves_remark(cfg);
}

static inline int cfg_apply(struct cfg *cfg, struct ini_ctx *ctx)
{
  size_t i;
  int ret;

  cfg_steal(cfg, &ctx->cfg);

  if (cfg->default_priority_string) {
    _gnutls_default_priority_string = cfg->default_priority_string;
  }

  if (cfg->allowlisting) {
    /* also updates `flags` of global `hash_algorithms[]` */
    ret = cfg_hashes_set_array(cfg, ctx->hashes, ctx->hashes_size);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
    /* also updates `flags` of global `sign_algorithms[]` */
    ret = cfg_sigs_set_arrays(cfg, ctx->sigs, ctx->sigs_size,
            ctx->sigs_for_cert,
            ctx->sigs_for_cert_size);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
    /* also updates `supported` field of global `sup_versions[]` */
    ret = cfg_versions_set_array(cfg,
               ctx->versions, ctx->versions_size);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
    /* also updates `supported` field of global `ecc_curves[]` */
    ret = cfg_ecc_curves_set_array(cfg,
                 ctx->curves, ctx->curves_size);
    if (unlikely(ret < 0)) {
      return gnutls_assert_val(ret);
    }
  } else {
    /* updates same global arrays as above, but doesn't store
     * the algorithms into the `struct cfg` as allowlisting does.
     * blocklisting doesn't allow relaxing the restrictions */
    for (i = 0; i < ctx->hashes_size; i++) {
      ret = _gnutls_digest_mark_insecure(ctx->hashes[i]);
      if (unlikely(ret < 0)) {
        return ret;
      }
    }
    for (i = 0; i < ctx->sigs_size; i++) {
      ret = _gnutls_sign_mark_insecure(ctx->sigs[i],
               _INSECURE);
      if (unlikely(ret < 0)) {
        return ret;
      }
    }
    for (i = 0; i < ctx->sigs_for_cert_size; i++) {
      ret =
          _gnutls_sign_mark_insecure(ctx->sigs_for_cert[i],
                   _INSECURE_FOR_CERTS);
      if (unlikely(ret < 0)) {
        return ret;
      }
    }
    for (i = 0; i < ctx->versions_size; i++) {
      ret = _gnutls_version_mark_disabled(ctx->versions[i]);
      if (unlikely(ret < 0)) {
        return ret;
      }
    }
    for (i = 0; i < ctx->curves_size; i++) {
      ret = _gnutls_ecc_curve_mark_disabled(ctx->curves[i]);
      if (unlikely(ret < 0)) {
        return ret;
      }
    }
  }

  return 0;
}

/* This function parses the global section of the configuration file.
 */
static int global_ini_handler(void *ctx, const char *section, const char *name,
            const char *value)
{
  char *p;
  char str[MAX_ALGO_NAME];
  struct cfg *cfg = ctx;

  if (section != NULL && c_strcasecmp(section, GLOBAL_SECTION) == 0) {
    if (c_strcasecmp(name, "override-mode") == 0) {
      p = clear_spaces(value, str);
      if (c_strcasecmp(p, "allowlist") == 0) {
        cfg->allowlisting = true;
      } else if (c_strcasecmp(p, "blocklist") == 0) {
        cfg->allowlisting = false;
      } else {
        _gnutls_debug_log
            ("cfg: unknown override mode %s\n", p);
        if (fail_on_invalid_config)
          return 0;
      }
    } else if (c_strcasecmp(name, "ktls") == 0) {
      p = clear_spaces(value, str);
      if (c_strcasecmp(p, "true") == 0) {
        cfg->ktls_enabled = true;
      } else if (c_strcasecmp(p, "false") == 0) {
        cfg->ktls_enabled = false;
      } else {
        _gnutls_debug_log("cfg: unknown ktls mode %s\n",
              p);
        if (fail_on_invalid_config)
          return 0;
      }
    } else {
      _gnutls_debug_log("unknown parameter %s\n", name);
      if (fail_on_invalid_config)
        return 0;
    }
  }

  return 1;
}

static bool override_allowed(bool allowlisting, const char *name)
{
  static const struct {
    const char *allowlist_name;
    const char *blocklist_name;
  } names[] = {
    {"secure-hash", "insecure-hash"},
    {"secure-sig", "insecure-sig"},
    {"secure-sig-for-cert", "insecure-sig-for-cert"},
    {"enabled-version", "disabled-version"},
    {"enabled-curve", "disabled-curve"},
    {"tls-enabled-cipher", "tls-disabled-cipher"},
    {"tls-enabled-group", "tls-disabled-group"},
    {"tls-enabled-kx", "tls-disabled-kx"},
    {"tls-enabled-mac", "tls-disabled-mac"}
  };
  size_t i;

  for (i = 0; i < sizeof(names) / sizeof(names[0]); i++) {
    if (c_strcasecmp(name,
         allowlisting ?
         names[i].blocklist_name :
         names[i].allowlist_name) == 0)
      return false;
  }

  return true;
}

/* This function parses a gnutls configuration file.  Updating internal settings
 * according to the parsed configuration is done by cfg_apply.
 */
static int cfg_ini_handler(void *_ctx, const char *section, const char *name,
         const char *value)
{
  char *p;
  int ret;
  unsigned i;
  char str[MAX_ALGO_NAME];
  struct ini_ctx *ctx = _ctx;
  struct cfg *cfg = &ctx->cfg;

  /* Note that we intentionally overwrite the value above; inih does
   * not use that value after we handle it. */

  /* Parse sections */
  if (section == NULL || section[0] == 0
      || c_strcasecmp(section, CUSTOM_PRIORITY_SECTION) == 0) {
    _gnutls_debug_log("cfg: adding priority: %s -> %s\n", name,
          value);

    ret =
        _name_val_array_append(&cfg->priority_strings, name, value);
    if (ret < 0)
      return 0;
  } else if (c_strcasecmp(section, OVERRIDES_SECTION) == 0) {
    if (!override_allowed(cfg->allowlisting, name)) {
      _gnutls_debug_log
          ("cfg: %s is not allowed in this mode\n", name);
      if (fail_on_invalid_config)
        return 0;
    } else if (c_strcasecmp(name, "default-priority-string") == 0) {
      if (cfg->default_priority_string) {
        gnutls_free(cfg->default_priority_string);
        cfg->default_priority_string = NULL;
      }
      p = clear_spaces(value, str);
      _gnutls_debug_log
          ("cfg: setting default-priority-string to %s\n", p);
      if (strlen(p) > 0) {
        cfg->default_priority_string = gnutls_strdup(p);
        if (!cfg->default_priority_string) {
          _gnutls_debug_log
              ("cfg: failed setting default-priority-string\n");
          return 0;
        }
      } else {
        _gnutls_debug_log
            ("cfg: empty default-priority-string, using default\n");
        if (fail_on_invalid_config)
          return 0;
      }
    } else if (c_strcasecmp(name, "insecure-hash") == 0 ||
         c_strcasecmp(name, "secure-hash") == 0) {
      gnutls_digest_algorithm_t dig, *tmp;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: marking hash %s as secure\n", p);
      } else {
        _gnutls_debug_log
            ("cfg: marking hash %s as insecure\n", p);
      }

      dig = gnutls_digest_get_id(p);
      if (dig == GNUTLS_DIG_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: found unknown hash %s in %s\n", p,
             name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      tmp = _gnutls_reallocarray(ctx->hashes,
               ctx->hashes_size + 1,
               sizeof
               (gnutls_digest_algorithm_t));
      if (!tmp) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: failed marking hash %s as secure\n",
               p);
        } else {
          _gnutls_debug_log
              ("cfg: failed marking hash %s as insecure\n",
               p);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      ctx->hashes = tmp;
      ctx->hashes[ctx->hashes_size] = dig;
      ctx->hashes_size++;
    } else if (c_strcasecmp(name, "insecure-sig") == 0 ||
         c_strcasecmp(name, "secure-sig") == 0) {
      gnutls_sign_algorithm_t sig, *tmp;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: marking signature %s as secure\n",
             p);
      } else {
        _gnutls_debug_log
            ("cfg: marking signature %s as insecure\n",
             p);
      }

      sig = gnutls_sign_get_id(p);
      if (sig == GNUTLS_SIGN_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: found unknown signature algorithm %s in %s\n",
             p, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      tmp = _gnutls_reallocarray(ctx->sigs,
               ctx->sigs_size + 1,
               sizeof
               (gnutls_sign_algorithm_t));
      if (!tmp) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: failed marking signature %s as secure\n",
               p);
        } else {
          _gnutls_debug_log
              ("cfg: failed marking signature %s as insecure\n",
               p);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      ctx->sigs = tmp;
      ctx->sigs[ctx->sigs_size] = sig;
      ctx->sigs_size++;
    } else if (c_strcasecmp(name, "insecure-sig-for-cert") == 0 ||
         c_strcasecmp(name, "secure-sig-for-cert") == 0) {
      gnutls_sign_algorithm_t sig, *tmp;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: marking signature %s as secure for certs\n",
             p);
      } else {
        _gnutls_debug_log
            ("cfg: marking signature %s as insecure for certs\n",
             p);
      }

      sig = gnutls_sign_get_id(p);
      if (sig == GNUTLS_SIGN_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: found unknown signature algorithm %s in %s\n",
             p, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      tmp = _gnutls_reallocarray(ctx->sigs_for_cert,
               ctx->sigs_for_cert_size + 1,
               sizeof
               (gnutls_sign_algorithm_t));
      if (!tmp) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: failed marking signature %s as secure for certs\n",
               p);
        } else {
          _gnutls_debug_log
              ("cfg: failed marking signature %s as insecure for certs\n",
               p);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      ctx->sigs_for_cert = tmp;
      ctx->sigs_for_cert[ctx->sigs_for_cert_size] = sig;
      ctx->sigs_for_cert_size++;
    } else if (c_strcasecmp(name, "disabled-version") == 0 ||
         c_strcasecmp(name, "enabled-version") == 0) {
      gnutls_protocol_t prot, *tmp;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log("cfg: enabling version %s\n",
              p);
      } else {
        _gnutls_debug_log("cfg: disabling version %s\n",
              p);
      }

      prot = gnutls_protocol_get_id(p);
      if (prot == GNUTLS_VERSION_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: found unknown version %s in %s\n", p,
             name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      tmp = _gnutls_reallocarray(ctx->versions,
               ctx->versions_size + 1,
               sizeof(gnutls_protocol_t));
      if (!tmp) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: failed enabling version %s\n",
               p);
        } else {
          _gnutls_debug_log
              ("cfg: failed disabling version %s\n",
               p);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      ctx->versions = tmp;
      ctx->versions[ctx->versions_size] = prot;
      ctx->versions_size++;
    } else if (c_strcasecmp(name, "disabled-curve") == 0 ||
         c_strcasecmp(name, "enabled-curve") == 0) {
      gnutls_ecc_curve_t curve, *tmp;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log("cfg: enabling curve %s\n",
              p);
      } else {
        _gnutls_debug_log("cfg: disabling curve %s\n",
              p);
      }

      curve = gnutls_ecc_curve_get_id(p);
      if (curve == GNUTLS_ECC_CURVE_INVALID) {
        _gnutls_debug_log
            ("cfg: found unknown curve %s in %s\n", p,
             name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      tmp = _gnutls_reallocarray(ctx->curves,
               ctx->curves_size + 1,
               sizeof(gnutls_ecc_curve_t));
      if (!tmp) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: failed enabling curve %s\n",
               p);
        } else {
          _gnutls_debug_log
              ("cfg: failed disabling curve %s\n",
               p);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      ctx->curves = tmp;
      ctx->curves[ctx->curves_size] = curve;
      ctx->curves_size++;
    } else if (c_strcasecmp(name, "min-verification-profile") == 0) {
      gnutls_certificate_verification_profiles_t profile;
      profile =
          gnutls_certificate_verification_profile_get_id
          (value);

      if (profile == GNUTLS_PROFILE_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: found unknown profile %s in %s\n",
             value, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      cfg->verification_profile = profile;
    } else if (c_strcasecmp(name, "tls-disabled-cipher") == 0 ||
         c_strcasecmp(name, "tls-enabled-cipher") == 0) {
      gnutls_cipher_algorithm_t algo;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: enabling cipher %s for TLS\n", p);
      } else {
        _gnutls_debug_log
            ("cfg: disabling cipher %s for TLS\n", p);
      }

      algo = gnutls_cipher_get_id(p);
      if (algo == GNUTLS_CIPHER_UNKNOWN) {
        _gnutls_debug_log
            ("cfg: unknown algorithm %s listed at %s\n",
             p, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      i = 0;
      while (cfg->ciphers[i] != 0)
        i++;

      if (i > MAX_ALGOS - 1) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: too many (%d) enabled ciphers from %s\n",
               i, name);
        } else {
          _gnutls_debug_log
              ("cfg: too many (%d) disabled ciphers from %s\n",
               i, name);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      cfg->ciphers[i] = algo;
      cfg->ciphers[i + 1] = 0;

    } else if (c_strcasecmp(name, "tls-disabled-mac") == 0 ||
         c_strcasecmp(name, "tls-enabled-mac") == 0) {
      gnutls_mac_algorithm_t algo;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: enabling MAC %s for TLS\n", p);
      } else {
        _gnutls_debug_log
            ("cfg: disabling MAC %s for TLS\n", p);
      }

      algo = gnutls_mac_get_id(p);
      if (algo == 0) {
        _gnutls_debug_log
            ("cfg: unknown algorithm %s listed at %s\n",
             p, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      i = 0;
      while (cfg->macs[i] != 0)
        i++;

      if (i > MAX_ALGOS - 1) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: too many (%d) enabled MACs from %s\n",
               i, name);
        } else {
          _gnutls_debug_log
              ("cfg: too many (%d) disabled MACs from %s\n",
               i, name);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      cfg->macs[i] = algo;
      cfg->macs[i + 1] = 0;
    } else if (c_strcasecmp(name, "tls-disabled-group") == 0 ||
         c_strcasecmp(name, "tls-enabled-group") == 0) {
      gnutls_group_t algo;

      p = clear_spaces(value, str);

      if (c_strncasecmp(p, "GROUP-", 6) == 0)
        p += 6;

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: enabling group %s for TLS\n", p);
      } else {
        _gnutls_debug_log
            ("cfg: disabling group %s for TLS\n", p);
      }

      algo = _gnutls_group_get_id(p);
      if (algo == 0) {
        _gnutls_debug_log
            ("cfg: unknown group %s listed at %s\n", p,
             name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      i = 0;
      while (cfg->groups[i] != 0)
        i++;

      if (i > MAX_ALGOS - 1) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: too many (%d) enabled groups from %s\n",
               i, name);
        } else {
          _gnutls_debug_log
              ("cfg: too many (%d) disabled groups from %s\n",
               i, name);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      cfg->groups[i] = algo;
      cfg->groups[i + 1] = 0;
    } else if (c_strcasecmp(name, "tls-disabled-kx") == 0 ||
         c_strcasecmp(name, "tls-enabled-kx") == 0) {
      unsigned algo;

      p = clear_spaces(value, str);

      if (cfg->allowlisting) {
        _gnutls_debug_log
            ("cfg: enabling key exchange %s for TLS\n",
             p);
      } else {
        _gnutls_debug_log
            ("cfg: disabling key exchange %s for TLS\n",
             p);
      }

      algo = gnutls_kx_get_id(p);
      if (algo == 0) {
        _gnutls_debug_log
            ("cfg: unknown key exchange %s listed at %s\n",
             p, name);
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }

      i = 0;
      while (cfg->kxs[i] != 0)
        i++;

      if (i > MAX_ALGOS - 1) {
        if (cfg->allowlisting) {
          _gnutls_debug_log
              ("cfg: too many (%d) enabled key exchanges from %s\n",
               i, name);
        } else {
          _gnutls_debug_log
              ("cfg: too many (%d) disabled key exchanges from %s\n",
               i, name);
        }
        if (fail_on_invalid_config)
          return 0;
        goto exit;
      }
      cfg->kxs[i] = algo;
      cfg->kxs[i + 1] = 0;
    } else {
      _gnutls_debug_log("unknown parameter %s\n", name);
      if (fail_on_invalid_config)
        return 0;
    }
  } else if (c_strcasecmp(section, GLOBAL_SECTION) != 0) {
    _gnutls_debug_log("cfg: unknown section %s\n", section);
    if (fail_on_invalid_config)
      return 0;
  }

 exit:
  return 1;
}

static int /* not locking system_wide_config */
construct_system_wide_priority_string(gnutls_buffer_st * buf)
{
  int ret;
  size_t i;

  _gnutls_buffer_init(buf);

  ret = _gnutls_buffer_append_str(buf, "NONE");
  if (ret < 0) {
    _gnutls_buffer_clear(buf);
    return ret;
  }

  for (i = 0; system_wide_config.kxs[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_kx_get_name
            (system_wide_config.kxs[i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }

  for (i = 0; system_wide_config.groups[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+GROUP-");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_group_get_name
            (system_wide_config.groups[i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }

  for (i = 0; system_wide_config.ciphers[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_cipher_get_name
            (system_wide_config.ciphers
             [i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }

  for (i = 0; system_wide_config.macs[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_mac_get_name
            (system_wide_config.macs[i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }

  for (i = 0; system_wide_config.sigs[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+SIGN-");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_sign_get_name
            (system_wide_config.sigs[i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }

  for (i = 0; system_wide_config.versions[i] != 0; i++) {
    ret = _gnutls_buffer_append_str(buf, ":+VERS-");
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }

    ret = _gnutls_buffer_append_str(buf,
            gnutls_protocol_get_name
            (system_wide_config.versions
             [i]));
    if (ret < 0) {
      _gnutls_buffer_clear(buf);
      return ret;
    }
  }
  return 0;
}

static int /* not locking system_wide_config */
update_system_wide_priority_string(void)
{
  /* doesn't do locking, _gnutls_update_system_priorities does */
  gnutls_buffer_st buf;
  int ret;

  ret = construct_system_wide_priority_string(&buf);
  if (ret < 0) {
    _gnutls_debug_log("cfg: unable to construct "
          "system-wide priority string: %s",
          gnutls_strerror(ret));
    _gnutls_buffer_clear(&buf);
    return ret;
  }

  gnutls_free(system_wide_config.priority_string);
  system_wide_config.priority_string = gnutls_strdup((char *)buf.data);
  _gnutls_buffer_clear(&buf);

  return 0;
}

static int _gnutls_update_system_priorities(bool defer_system_wide)
{
  int ret, err = 0;
  struct stat sb;
  FILE *fp;
  gnutls_buffer_st buf;
  struct ini_ctx ctx;

  ret = gnutls_rwlock_rdlock(&system_wide_config_rwlock);
  if (ret < 0) {
    return gnutls_assert_val(ret);
  }

  if (stat(system_priority_file, &sb) < 0) {
    _gnutls_debug_log("cfg: unable to access: %s: %d\n",
          system_priority_file, errno);
    goto out;
  }

  if (system_priority_file_loaded &&
      system_priority_last_mod == sb.st_mtime) {
    _gnutls_debug_log("cfg: system priority %s has not changed\n",
          system_priority_file);
    if (system_wide_config.priority_string) {
      goto out; /* nothing to do */
    }
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);

  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    return gnutls_assert_val(ret);
  }

  /* Another thread could have successfully re-read system-wide config,
   * skip re-reading if the mtime it has used is exactly the same.
   */
  if (system_priority_file_loaded) {
    system_priority_file_loaded =
        (system_priority_last_mod == sb.st_mtime);
  }

  if (!system_priority_file_loaded) {
    _name_val_array_clear(&system_wide_config.priority_strings);

    gnutls_free(system_wide_config.priority_string);
    system_wide_config.priority_string = NULL;

    fp = fopen(system_priority_file, "re");
    if (fp == NULL) {
      _gnutls_debug_log("cfg: unable to open: %s: %d\n",
            system_priority_file, errno);
      goto out;
    }
    /* Parsing the configuration file needs to be done in 2 phases:
     * first parsing the [global] section
     * and then the other sections,
     * because the [global] section modifies the parsing behavior.
     */
    memset(&ctx, 0, sizeof(ctx));
    err = ini_parse_file(fp, global_ini_handler, &ctx);
    if (!err) {
      if (fseek(fp, 0L, SEEK_SET) < 0) {
        _gnutls_debug_log("cfg: unable to rewind: %s\n",
              system_priority_file);
        if (fail_on_invalid_config)
          exit(1);
      }
      err = ini_parse_file(fp, cfg_ini_handler, &ctx);
    }
    fclose(fp);
    if (err) {
      ini_ctx_deinit(&ctx);
      _gnutls_debug_log("cfg: unable to parse: %s: %d\n",
            system_priority_file, err);
      goto out;
    }
    cfg_apply(&system_wide_config, &ctx);
    ini_ctx_deinit(&ctx);
    _gnutls_debug_log("cfg: loaded system config %s mtime %lld\n",
          system_priority_file,
          (unsigned long long)sb.st_mtime);

  }

  if (system_wide_config.allowlisting) {
    if (defer_system_wide) {
      /* try constructing a priority string,
       * but don't apply it yet, at this point
       * we're only interested in whether we can */
      ret = construct_system_wide_priority_string(&buf);
      _gnutls_buffer_clear(&buf);
      _gnutls_debug_log("cfg: deferred setting "
            "system-wide priority string\n");
    } else {
      ret = update_system_wide_priority_string();
      _gnutls_debug_log("cfg: finalized "
            "system-wide priority string\n");
    }
    if (ret < 0) {
      _gnutls_debug_log
          ("cfg: unable to build priority string: %s\n",
           gnutls_strerror(ret));
      if (fail_on_invalid_config)
        exit(1);
      goto out;
    }
  }

  system_priority_file_loaded = 1;
  system_priority_last_mod = sb.st_mtime;

 out:
  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);

  if (err && fail_on_invalid_config) {
    exit(1);
  }

  return ret;
}

void _gnutls_prepare_to_load_system_priorities(void)
{
  const char *p;
  int ret;

  p = secure_getenv("GNUTLS_SYSTEM_PRIORITY_FILE");
  if (p != NULL)
    system_priority_file = p;

  p = secure_getenv("GNUTLS_SYSTEM_PRIORITY_FAIL_ON_INVALID");
  if (p != NULL && p[0] == '1' && p[1] == 0)
    fail_on_invalid_config = 1;

  ret = _gnutls_update_system_priorities(true /* defer_system_wide */ );
  if (ret < 0) {
    _gnutls_debug_log("failed to update system priorities: %s\n",
          gnutls_strerror(ret));
  }
}

void _gnutls_unload_system_priorities(void)
{
  _name_val_array_clear(&system_wide_config.priority_strings);
  gnutls_free(system_wide_config.priority_string);
  _clear_default_system_priority();
  system_priority_last_mod = 0;
}

/**
 * gnutls_get_system_config_file:
 *
 * Returns the filename of the system wide configuration
 * file to be loaded by the library.
 *
 * Returns: a constant pointer to the config file path
 *
 * Since: 3.6.9
 **/
const char *gnutls_get_system_config_file(void)
{
  return system_priority_file;
}

#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)
{
  const char *p = priorities;
  char *additional = NULL;
  char *resolved = NULL;
  const char *ss, *ss_next;
  unsigned ss_len, ss_next_len;
  size_t n, n2 = 0;
  int ret;

  while (c_isspace(*p)) {
    p++;
  }

  /* Cannot reduce further. */
  if (*p != '@') {
    return gnutls_strdup(p);
  }

  ss = p + 1;
  additional = strchr(ss, ':');
  if (additional) {
    additional++;
  }

  /* Always try to refresh the cached data, to allow it to be
   * updated without restarting all applications.
   */
  ret = _gnutls_update_system_priorities(false /* defer_system_wide */ );
  if (ret < 0) {
    _gnutls_debug_log("failed to update system priorities: %s\n",
          gnutls_strerror(ret));
  }

  do {
    ss_next = strchr(ss, ',');
    if (ss_next) {
      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;
    }

    ret = gnutls_rwlock_rdlock(&system_wide_config_rwlock);
    if (ret < 0) {
      _gnutls_debug_log
          ("cannot read system priority strings: %s\n",
           gnutls_strerror(ret));
      break;
    }
    if (system_wide_config.allowlisting &&
        ss_len == sizeof(LEVEL_SYSTEM) - 1 &&
        strncmp(LEVEL_SYSTEM, ss, ss_len) == 0) {
      p = system_wide_config.priority_string;
    } else {
      p = _name_val_array_value
          (system_wide_config.priority_strings, ss, ss_len);
    }

    _gnutls_debug_log("resolved '%.*s' to '%s', next '%.*s'\n",
          ss_len, ss, S(p), ss_next_len, S(ss_next));

    if (p) {
      n = strlen(p);
      if (additional) {
        n2 = strlen(additional);
      }

      resolved = gnutls_malloc(n + n2 + 1 + 1);
      if (resolved) {
        memcpy(resolved, p, n);
        if (additional) {
          resolved[n] = ':';
          memcpy(&resolved[n + 1], additional,
                 n2);
          resolved[n + n2 + 1] = 0;
        } else {
          resolved[n] = 0;
        }
      }
    }

    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);

    ss = ss_next;
  } while (ss && !resolved);

  if (resolved) {
    _gnutls_debug_log("selected priority string: %s\n", resolved);
  } else {
    _gnutls_debug_log("unable to resolve %s\n", priorities);
  }

  return resolved;
}

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.num_priorities; i++) {
    ge = _gnutls_id_to_group(priority_cache->
           _supported_ecc.priorities[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.num_priorities; i++) {
    ge = _gnutls_id_to_group(priority_cache->
           _supported_ecc.priorities[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;
    }
  }
}

/* This function was originally precalculating ciphersuite-specific items, however
 * it has now extended to much more than that. It provides a consistency check to
 * set parameters, and in cases it applies policy specific items.
 */
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_pre_tls12 = 0, have_tls12 = 0;
  unsigned have_psk = 0, have_null = 0, have_rsa_psk = 0;
  gnutls_digest_algorithm_t prf_digest;
  int ret = 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;

  /* The following requires a lock so there are no inconsistencies in the
   * members of system_wide_config loaded from the config file. */
  ret = gnutls_rwlock_rdlock(&system_wide_config_rwlock);
  if (ret < 0) {
    return gnutls_assert_val(ret);
  }

  /* in blocklisting mode, apply system wide disablement of key exchanges,
   * groups, MACs, and ciphers. */
  if (!system_wide_config.allowlisting) {
    /* disable key exchanges which are globally disabled */
    z = 0;
    while (system_wide_config.kxs[z] != 0) {
      for (i = j = 0; i < priority_cache->_kx.num_priorities;
           i++) {
        if (priority_cache->_kx.priorities[i] !=
            system_wide_config.kxs[z])
          priority_cache->_kx.priorities[j++] =
              priority_cache->_kx.priorities[i];
      }
      priority_cache->_kx.num_priorities = j;
      z++;
    }

    /* disable groups which are globally disabled */
    z = 0;
    while (system_wide_config.groups[z] != 0) {
      for (i = j = 0;
           i < priority_cache->_supported_ecc.num_priorities;
           i++) {
        if (priority_cache->
            _supported_ecc.priorities[i] !=
            system_wide_config.groups[z])
          priority_cache->
              _supported_ecc.priorities[j++] =
              priority_cache->
              _supported_ecc.priorities[i];
      }
      priority_cache->_supported_ecc.num_priorities = j;
      z++;
    }

    /* disable ciphers which are globally disabled */
    z = 0;
    while (system_wide_config.ciphers[z] != 0) {
      for (i = j = 0;
           i < priority_cache->_cipher.num_priorities; i++) {
        if (priority_cache->_cipher.priorities[i] !=
            system_wide_config.ciphers[z])
          priority_cache->
              _cipher.priorities[j++] =
              priority_cache->
              _cipher.priorities[i];
      }
      priority_cache->_cipher.num_priorities = j;
      z++;
    }

    /* disable MACs which are globally disabled */
    z = 0;
    while (system_wide_config.macs[z] != 0) {
      for (i = j = 0; i < priority_cache->_mac.num_priorities;
           i++) {
        if (priority_cache->_mac.priorities[i] !=
            system_wide_config.macs[z])
          priority_cache->_mac.priorities[j++] =
              priority_cache->_mac.priorities[i];
      }
      priority_cache->_mac.num_priorities = j;
      z++;
    }
  }

  for (j = 0; j < priority_cache->_cipher.num_priorities; j++) {
    if (priority_cache->_cipher.priorities[j] == GNUTLS_CIPHER_NULL) {
      have_null = 1;
      break;
    }
  }

  for (i = 0; i < priority_cache->_kx.num_priorities; i++) {
    if (IS_SRP_KX(priority_cache->_kx.priorities[i])) {
      have_srp = 1;
    } else if (_gnutls_kx_is_psk(priority_cache->_kx.priorities[i])) {
      if (priority_cache->_kx.priorities[i] ==
          GNUTLS_KX_RSA_PSK)
        have_rsa_psk = 1;
      else
        have_psk = 1;
    }
  }

  /* disable TLS versions which are added but are unsupported */
  for (i = j = 0; i < priority_cache->protocol.num_priorities; i++) {
    vers = version_to_entry(priority_cache->protocol.priorities[i]);
    if (!vers || vers->supported ||
        (system_wide_config.allowlisting &&
         vers->supported_revertible))
      priority_cache->protocol.priorities[j++] =
          priority_cache->protocol.priorities[i];
  }
  priority_cache->protocol.num_priorities = j;

  /* 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
      || priority_cache->no_extensions) {
    for (i = j = 0; i < priority_cache->protocol.num_priorities;
         i++) {
      vers =
          version_to_entry(priority_cache->
               protocol.priorities[i]);
      if (!vers || !vers->tls13_sem)
        priority_cache->protocol.priorities[j++] =
            priority_cache->protocol.priorities[i];
    }
    priority_cache->protocol.num_priorities = j;
  }

  for (i = 0; i < priority_cache->protocol.num_priorities; i++) {
    vers = version_to_entry(priority_cache->protocol.priorities[i]);
    if (!vers)
      continue;

    if (vers->transport == GNUTLS_STREAM) { /* TLS */
      tls_sig_sem |= vers->tls_sig_sem;
      if (vers->tls13_sem)
        have_tls13 = 1;

      if (vers->id == GNUTLS_TLS1_2)
        have_tls12 = 1;
      else if (vers->id < GNUTLS_TLS1_2)
        have_pre_tls12 = 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;

      /* we need to introduce similar handling to above
       * when DTLS1.3 is supported */

      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)) {
    ret = gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
    goto out;
  }

  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.num_priorities = 0;
  }

  /* Add TLS 1.3 ciphersuites (no KX) */
  for (j = 0; j < priority_cache->_cipher.num_priorities; j++) {
    for (z = 0; z < priority_cache->_mac.num_priorities; z++) {
      ce = cipher_suite_get(0,
                priority_cache->
                _cipher.priorities[j],
                priority_cache->
                _mac.priorities[z]);
      if (ce == NULL)
        continue;

      prf_digest = MAC_TO_DIG(ce->prf);
      if (prf_digest == GNUTLS_DIG_UNKNOWN)
        continue;
      if (_gnutls_digest_is_insecure(prf_digest))
        continue;

      if (priority_cache->cs.size < MAX_CIPHERSUITE_SIZE)
        priority_cache->cs.entry[priority_cache->
               cs.size++] = ce;
    }
  }

  for (i = 0; i < priority_cache->_kx.num_priorities; i++) {
    for (j = 0; j < priority_cache->_cipher.num_priorities; j++) {
      for (z = 0; z < priority_cache->_mac.num_priorities;
           z++) {
        ce = cipher_suite_get(priority_cache->
                  _kx.priorities[i],
                  priority_cache->
                  _cipher.priorities[j],
                  priority_cache->
                  _mac.priorities[z]);
        if (ce == NULL)
          continue;

        prf_digest = MAC_TO_DIG(ce->prf);
        if (prf_digest == GNUTLS_DIG_UNKNOWN)
          continue;
        if (_gnutls_digest_is_insecure(prf_digest))
          continue;

        if (priority_cache->cs.size ==
            MAX_CIPHERSUITE_SIZE)
          continue;
        priority_cache->cs.entry[priority_cache->
               cs.size++] = ce;
        if (!have_ec
            && (_gnutls_kx_is_ecc(ce->kx_algorithm)
          ||
          _gnutls_kx_is_vko_gost
          (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.num_priorities;
         i++) {
      const gnutls_group_entry_st *ge;
      ge = _gnutls_id_to_group(priority_cache->
             _supported_ecc.priorities[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.num_priorities; i++) {
    se = _gnutls_sign_to_entry(priority_cache->
             _sign_algo.priorities[i]);
    if (se != NULL
        && priority_cache->sigalg.size <
        sizeof(priority_cache->sigalg.entry) /
        sizeof(priority_cache->sigalg.entry[0])) {
      /* if the signature algorithm semantics is not
       * compatible with the protocol's, or the algorithm is
       * marked as insecure, then skip. */
      if ((se->aid.tls_sem & tls_sig_sem) == 0 ||
          !_gnutls_sign_is_secure2(se,
                 system_wide_config.allowlisting
                 ?
                 GNUTLS_SIGN_FLAG_ALLOW_INSECURE_REVERTIBLE
                 : 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.num_priorities, 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.num_priorities = 0;

    /* we need to eliminate TLS 1.2 or DTLS 1.2 and later protocols */
    for (i = 0; i < priority_cache->protocol.num_priorities; i++) {
      if (priority_cache->protocol.priorities[i] <
          GNUTLS_TLS1_2) {
        newp.priorities[newp.num_priorities++] =
            priority_cache->protocol.priorities[i];
      } else if (priority_cache->protocol.priorities[i] >=
           GNUTLS_DTLS_VERSION_MIN
           && priority_cache->protocol.priorities[i] <
           GNUTLS_DTLS1_2) {
        newp.priorities[newp.num_priorities++] =
            priority_cache->protocol.priorities[i];
      }
    }
    memcpy(&priority_cache->protocol, &newp, sizeof(newp));
  }

  if (unlikely(priority_cache->protocol.num_priorities == 0)) {
    ret = gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
    goto out;
  }
#ifndef ENABLE_SSL3
  else if (unlikely
     (priority_cache->protocol.num_priorities == 1
      && priority_cache->protocol.priorities[0] == GNUTLS_SSL3)) {
    ret = gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
    goto out;
  }
#endif

  if (unlikely(priority_cache->cs.size == 0)) {
    ret = gnutls_assert_val(GNUTLS_E_NO_PRIORITIES_WERE_SET);
    goto out;
  }

  /* when TLS 1.3 is available we must have groups set; additionally
   * we require TLS1.2 to be enabled if TLS1.3 is asked for, and
   * a pre-TLS1.2 protocol is there; that is because servers which
   * do not support TLS1.3 will negotiate TLS1.2 if seen a TLS1.3 handshake */
  if (unlikely
      ((!have_psk && tlsmax && tlsmax->id >= GNUTLS_TLS1_3
        && priority_cache->groups.size == 0)) || (!have_tls12
              && have_pre_tls12
              && have_tls13)) {
    for (i = j = 0; i < priority_cache->protocol.num_priorities;
         i++) {
      vers =
          version_to_entry(priority_cache->
               protocol.priorities[i]);
      if (!vers || vers->transport != GNUTLS_STREAM
          || !vers->tls13_sem)
        priority_cache->protocol.priorities[j++] =
            priority_cache->protocol.priorities[i];
    }
    priority_cache->protocol.num_priorities = j;
  }

  /* ensure that the verification profile is not lower from the configured */
  if (system_wide_config.verification_profile) {
    gnutls_sec_param_t level = priority_cache->level;
    gnutls_sec_param_t system_wide_level =
        _gnutls_profile_to_sec_level
        (system_wide_config.verification_profile);

    if (level < system_wide_level) {
      ENABLE_PROFILE(priority_cache,
               system_wide_config.verification_profile);
    }
  }

 out:
  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
}

/**
 * gnutls_priority_init2:
 * @priority_cache: is a #gnutls_priority_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/config.
 * 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;

  *priority_cache = NULL;
  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);
  }
}

#define PRIO_MATCH(name) c_strncasecmp(&broken_list[i][1], name, sizeof(name) - 1)

/**
 * gnutls_priority_init:
 * @priority_cache: is a #gnutls_priority_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;
  /* For now TLS 1.3 middlebox compatibility mode is enabled by default.
   * This will eventually be disabled by default and moved to the %COMPAT
   * setting.
   */
  (*priority_cache)->tls13_compat_mode = true;
  (*priority_cache)->min_record_version = 1;
  gnutls_atomic_init(&(*priority_cache)->usage_cnt);

  if (_gnutls_fips_mode_enabled()) {
    (*priority_cache)->force_ext_master_secret = true;
  }

  if (system_wide_config.allowlisting && !priorities) {
    priorities = "@" LEVEL_SYSTEM;
  }
  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 (c_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 (PRIO_MATCH("VERS-") == 0) {
        if (PRIO_MATCH("VERS-TLS-ALL") == 0) {
          bulk_given_fn(&
                  (*priority_cache)->
                  protocol,
                  stream_protocol_priority);
        } else if (PRIO_MATCH("VERS-DTLS-ALL") == 0) {
          bulk_given_fn(&
                  (*priority_cache)->
                  protocol,
                  (bulk_given_fn ==
                   _add_priority) ?
                  dtls_protocol_priority :
                  dgram_protocol_priority);
        } else if (PRIO_MATCH("VERS-ALL") == 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 (PRIO_MATCH("COMP-") == 0) {
        /* ignore all compression methods */
        continue;
      } /* now check if the element is something like -ALGO */
      else if (PRIO_MATCH("CURVE-") == 0) {
        if (PRIO_MATCH("CURVE-ALL") == 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 (PRIO_MATCH("GROUP-") == 0) {
        if (PRIO_MATCH("GROUP-ALL") == 0) {
          bulk_fn(&
            (*priority_cache)->
            _supported_ecc,
            supported_groups_normal);
        } else if (PRIO_MATCH("GROUP-DH-ALL") == 0) {
          bulk_given_fn(&
                  (*priority_cache)->
                  _supported_ecc,
                  _supported_groups_dh);
        } else if (PRIO_MATCH("GROUP-EC-ALL") == 0) {
          bulk_given_fn(&
                  (*priority_cache)->
                  _supported_ecc,
                  _supported_groups_ecdh);
        } else if (PRIO_MATCH("GROUP-GOST-ALL") == 0) {
          bulk_given_fn(&
                  (*priority_cache)->
                  _supported_ecc,
                  _supported_groups_gost);
        } 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 (PRIO_MATCH("CTYPE-") == 0) {
        // Certificate types
        if (PRIO_MATCH("CTYPE-ALL") == 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 (PRIO_MATCH("CTYPE-CLI-") == 0) {
          // Client certificate types
          if (PRIO_MATCH("CTYPE-CLI-ALL") == 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 (PRIO_MATCH("CTYPE-SRV-") == 0) {
          // Server certificate types
          if (PRIO_MATCH("CTYPE-SRV-ALL") == 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 if (PRIO_MATCH("CTYPE-OPENPGP")
               == 0) {
            /* legacy openpgp option - ignore */
            continue;
          } else
            goto error;
        }
      } else if (PRIO_MATCH("SIGN-") == 0) {
        if (PRIO_MATCH("SIGN-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_sign_algo,
            sign_priority_default);
        } else if (PRIO_MATCH("SIGN-GOST-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_sign_algo,
            sign_priority_gost);
        } 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 (PRIO_MATCH("MAC-") == 0) {
        if (PRIO_MATCH("MAC-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_mac,
            mac_priority_normal);
        } else if (PRIO_MATCH("MAC-GOST-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_mac,
            mac_priority_gost);
        }
      } else if (PRIO_MATCH("CIPHER-") == 0) {
        if (PRIO_MATCH("CIPHER-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_cipher,
            cipher_priority_normal);
        } else if (PRIO_MATCH("CIPHER-GOST-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_cipher,
            cipher_priority_gost);
        }
      } else if (PRIO_MATCH("KX-") == 0) {
        if (PRIO_MATCH("KX-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_kx,
            kx_priority_secure);
        } else if (PRIO_MATCH("KX-GOST-ALL") == 0) {
          bulk_fn(&(*priority_cache)->_kx,
            kx_priority_gost);
        }
      } else if (PRIO_MATCH("GOST") == 0) {
        bulk_given_fn(&
                (*priority_cache)->_supported_ecc,
                _supported_groups_gost);
        bulk_fn(&(*priority_cache)->_sign_algo,
          sign_priority_gost);
        bulk_fn(&(*priority_cache)->_mac,
          mac_priority_gost);
        bulk_fn(&(*priority_cache)->_cipher,
          cipher_priority_gost);
        bulk_fn(&(*priority_cache)->_kx,
          kx_priority_gost);
      } 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:
  gnutls_free(darg);
  gnutls_priority_deinit(*priority_cache);
  *priority_cache = NULL;

  return ret;
}

/**
 * gnutls_priority_deinit:
 * @priority_cache: is a #gnutls_priority_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_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_supported_ecc.priorities;

  /* 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 < pcache->_supported_ecc.num_priorities; i++)
    if (pcache->_supported_ecc.priorities[i] > GNUTLS_ECC_CURVE_MAX)
      return i;

  return pcache->_supported_ecc.num_priorities;
}

/**
 * gnutls_priority_group_list:
 * @pcache: is a #gnutls_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_supported_ecc.priorities;
  return pcache->_supported_ecc.num_priorities;
}

/**
 * gnutls_priority_kx_list:
 * @pcache: is a #gnutls_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_kx.priorities;
  return pcache->_kx.num_priorities;
}

/**
 * gnutls_priority_cipher_list:
 * @pcache: is a #gnutls_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_cipher.priorities;
  return pcache->_cipher.num_priorities;
}

/**
 * gnutls_priority_mac_list:
 * @pcache: is a #gnutls_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_mac.priorities;
  return pcache->_mac.num_priorities;
}

/**
 * gnutls_priority_compression_list:
 * @pcache: is a #gnutls_priority_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_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->protocol.priorities;
  return pcache->protocol.num_priorities;
}

/**
 * gnutls_priority_sign_list:
 * @pcache: is a #gnutls_priority_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.num_priorities == 0)
    return 0;

  *list = pcache->_sign_algo.priorities;
  return pcache->_sign_algo.num_priorities;
}

/**
 * gnutls_priority_certificate_type_list:
 * @pcache: is a #gnutls_priority_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_priority_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.num_priorities > 0) {
      *list = pcache->client_ctype.priorities;
      return pcache->client_ctype.num_priorities;
    }
    break;
  case GNUTLS_CTYPE_SERVER:
    if (pcache->server_ctype.num_priorities > 0) {
      *list = pcache->server_ctype.priorities;
      return pcache->server_ctype.num_priorities;
    }
    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;
}

bool _gnutls_config_is_ktls_enabled(void)
{
  return system_wide_config.ktls_enabled;
}

/*
 * high-level interface for overriding configuration files
 */

static inline bool /* not locking system_wide_config */
system_wide_config_is_malleable(void)
{
  if (!system_wide_config.allowlisting) {
    _gnutls_audit_log(NULL, "allowlisting is not enabled!\n");
    return false;
  }
  if (system_wide_config.priority_string) {
    _gnutls_audit_log(NULL, "priority strings have already been "
          "initialized!\n");
    return false;
  }
  return true;
}

/**
 * gnutls_digest_set_secure:
 * @dig: is a digest algorithm
 * @secure: whether to mark the digest algorithm secure
 *
 * Modify the previous system wide setting that marked @dig as secure
 * or insecure. This only has effect when the algorithm is enabled
 * through the allowlisting mode in the configuration file, or when
 * the setting is modified with a prior call to this function.
 *
 * Since: 3.7.3
 */
int gnutls_digest_set_secure(gnutls_digest_algorithm_t dig, unsigned int secure)
{
#ifndef DISABLE_SYSTEM_CONFIG
  int ret;
  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(ret);
  }
  if (!system_wide_config_is_malleable()) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
  }

  if (secure) {
    ret = cfg_hashes_add(&system_wide_config, dig);
  } else {
    ret = cfg_hashes_remove(&system_wide_config, dig);
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
#else
  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
#endif
}

/**
 * gnutls_sign_set_secure:
 * @sign: the sign algorithm
 * @secure: whether to mark the sign algorithm secure
 *
 * Modify the previous system wide setting that marked @sign as secure
 * or insecure.  Calling this function is allowed
 * only if allowlisting mode is set in the configuration file,
 * and only if the system-wide TLS priority string
 * has not been initialized yet.
 * The intended usage is to provide applications with a way
 * to expressly deviate from the distribution or site defaults
 * inherited from the configuration file.
 * The modification is composable with further modifications
 * performed through the priority string mechanism.
 *
 * This function is not thread-safe and is intended to be called
 * in the main thread at the beginning of the process execution.
 *
 * Even when @secure is true, @sign is not marked as secure for the
 * use in certificates.  Use gnutls_sign_set_secure_for_certs() to
 * mark it secure as well for certificates.
 *
 * Returns: 0 on success or negative error code otherwise.
 *
 * Since: 3.7.3
 */
int gnutls_sign_set_secure(gnutls_sign_algorithm_t sign, unsigned int secure)
{
#ifndef DISABLE_SYSTEM_CONFIG
  int ret;
  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(ret);
  }
  if (!system_wide_config_is_malleable()) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
  }

  if (secure) {
    ret = cfg_sigs_add(&system_wide_config, sign);
  } else {
    ret = cfg_sigs_remove(&system_wide_config, sign);
    if (ret < 0) {
      (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
      return ret;
    }
    /* irregularity, distrusting also means distrusting for certs */
    ret = cfg_sigs_for_cert_remove(&system_wide_config, sign);
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
#else
  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
#endif
}

/**
 * gnutls_sign_set_secure_for_certs:
 * @sign: the sign algorithm
 * @secure: whether to mark the sign algorithm secure for certificates
 *
 * Modify the previous system wide setting that marked @sign as secure
 * or insecure for the use in certificates.  Calling this function is allowed
 * only if allowlisting mode is set in the configuration file,
 * and only if the system-wide TLS priority string
 * has not been initialized yet.
 * The intended usage is to provide applications with a way
 * to expressly deviate from the distribution or site defaults
 * inherited from the configuration file.
 * The modification is composable with further modifications
 * performed through the priority string mechanism.
 *
 * This function is not thread-safe and is intended to be called
 * in the main thread at the beginning of the process execution.

 * When @secure is true, @sign is marked as secure for any use unlike
 * gnutls_sign_set_secure().  Otherwise, it is marked as insecure only
 * for the use in certificates.  Use gnutls_sign_set_secure() to mark
 * it insecure for any uses.
 *
 * Returns: 0 on success or negative error code otherwise.
 *
 * Since: 3.7.3
 */
int
gnutls_sign_set_secure_for_certs(gnutls_sign_algorithm_t sign,
         unsigned int secure)
{
#ifndef DISABLE_SYSTEM_CONFIG
  int ret;
  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(ret);
  }
  if (!system_wide_config_is_malleable()) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
  }

  if (secure) {
    /* irregularity, trusting for certs means trusting in general */
    ret = cfg_sigs_add(&system_wide_config, sign);
    if (ret < 0) {
      (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
      return ret;
    }
    ret = cfg_sigs_for_cert_add(&system_wide_config, sign);
  } else {
    ret = cfg_sigs_for_cert_remove(&system_wide_config, sign);
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
#else
  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
#endif
}

/**
 * gnutls_protocol_set_enabled:
 * @version: is a (gnutls) version number
 * @enabled: whether to enable the protocol
 *
 * Control the previous system-wide setting that marked @version as
 * enabled or disabled.  Calling this function is allowed
 * only if allowlisting mode is set in the configuration file,
 * and only if the system-wide TLS priority string
 * has not been initialized yet.
 * The intended usage is to provide applications with a way
 * to expressly deviate from the distribution or site defaults
 * inherited from the configuration file.
 * The modification is composable with further modifications
 * performed through the priority string mechanism.
 *
 * This function is not thread-safe and is intended to be called
 * in the main thread at the beginning of the process execution.
 *
 * Returns: 0 on success or negative error code otherwise.
 *
 * Since: 3.7.3
 */
int       /* allowlisting-only */
 /* not thread-safe */ gnutls_protocol_set_enabled(gnutls_protocol_t version,
               unsigned int enabled)
{
#ifndef DISABLE_SYSTEM_CONFIG
  int ret;
  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(ret);
  }
  if (!system_wide_config_is_malleable()) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
  }

  if (enabled) {
    ret = cfg_versions_add(&system_wide_config, version);
  } else {
    ret = cfg_versions_remove(&system_wide_config, version);
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
#else
  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
#endif
}

/**
 * gnutls_ecc_curve_set_enabled:
 * @curve: is an ECC curve
 * @enabled: whether to enable the curve
 *
 * Modify the previous system wide setting that marked @curve as
 * enabled or disabled.  Calling this function is allowed
 * only if allowlisting mode is set in the configuration file,
 * and only if the system-wide TLS priority string
 * has not been initialized yet.
 * The intended usage is to provide applications with a way
 * to expressly deviate from the distribution or site defaults
 * inherited from the configuration file.
 * The modification is composable with further modifications
 * performed through the priority string mechanism.
 *
 * This function is not thread-safe and is intended to be called
 * in the main thread at the beginning of the process execution.
 *
 * Returns: 0 on success or negative error code otherwise.
 *
 * Since: 3.7.3
 */
int gnutls_ecc_curve_set_enabled(gnutls_ecc_curve_t curve, unsigned int enabled)
{
#ifndef DISABLE_SYSTEM_CONFIG
  int ret;
  ret = gnutls_rwlock_wrlock(&system_wide_config_rwlock);
  if (ret < 0) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(ret);
  }
  if (!system_wide_config_is_malleable()) {
    (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
    return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
  }

  if (enabled) {
    ret = cfg_ecc_curves_add(&system_wide_config, curve);
  } else {
    ret = cfg_ecc_curves_remove(&system_wide_config, curve);
  }

  (void)gnutls_rwlock_unlock(&system_wide_config_rwlock);
  return ret;
#else
  return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
#endif
}

Coverage Report

Created: 2023-03-26 07:33