Confere se esta enviando algo assim:
CURLOPT_URL => 'https://....',
CURLOPT_PORT => 8443,
CURLOPT_SSLCERT => $codificado,
CURLOPT_SSLKEY => $decodificado,
CURLOPT_CAINFO => $codificado,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => 0,
CURLOPT_FAILONERROR => 1,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_CUSTOMREQUEST => 'POST',