import os

def parse_version(v):
    return tuple(map(int, (v.split("."))))

gnutls_min_required_version = "3.6.13"

conf.CHECK_FUNCS('getrandom', headers='sys/random.h')
if not conf.CONFIG_SET('HAVE_GETRANDOM'):
   gnutls_min_required_version = "3.7.2"

gnutls_required_version = gnutls_min_required_version

conf.CHECK_CFG(package='gnutls',
               args=('"gnutls >= %s" --cflags --libs' % gnutls_required_version),
                     msg='Checking for GnuTLS >= %s' % gnutls_required_version,
                     mandatory=True)

gnutls_version_str = conf.cmd_and_log(conf.env.PKGCONFIG + ['--modversion', 'gnutls']).strip()
gnutls_version = parse_version(gnutls_version_str)

# Define gnutls as a system library
conf.SET_TARGET_TYPE('gnutls', 'SYSLIB')

# Check for gnutls_aead_cipher_encryptv2
#
# This is available since version 3.6.10, but 3.6.10 has a bug which got fixed
# in 3.6.11, see:
#
#     https://gitlab.com/gnutls/gnutls/-/merge_requests/1085
#
# 3.6.10 - 3.6.14 have a severe memory leak with AES-CCM
#     https://gitlab.com/gnutls/gnutls/-/merge_requests/1278
if (gnutls_version > parse_version('3.6.14')):
      conf.DEFINE('ALLOW_GNUTLS_AEAD_CIPHER_ENCRYPTV2_AES_CCM', 1)

# Check if gnutls has fips mode support
# gnutls_fips140_mode_enabled() is available since 3.3.0
fragment = '''
#include <gnutls/gnutls.h>
#include <stdlib.h>

int main(void)
{
    unsigned int ok;

    ok = gnutls_fips140_mode_enabled();

    return !ok;
}
'''

os.environ['GNUTLS_FORCE_FIPS_MODE'] = '1'
conf.CHECK_CODE(fragment,
                'HAVE_GNUTLS_FIPS_MODE_SUPPORTED',
                execute=True,
                addmain=False,
                add_headers=False,
                lib='gnutls',
                msg='Checking for gnutls fips mode support')
del os.environ['GNUTLS_FORCE_FIPS_MODE']