Testing X509 Certificate Expiry date with C - c

Question

How can I programaticlaly test if a X509 ?* certificate is expired or not ?
Is their a direct crypto api ?
or I have to get the not_after time and check it manually in my code ?

Answer 1

You didn't say which language so I was summing them up anyway:
php
$data = openssl_x509_parse(file_get_contents('/path/to/cert.crt'));
$validFrom = date('Y-m-d H:i:s', $data['validFrom_time_t']);
$validTo = date('Y-m-d H:i:s', $data['validTo_time_t']);
Java X509Certificate
InputStream inStream = null;
try (InputStream inStream = new FileInputStream("fileName-of-cert")) {
CertificateFactory cf = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate)cf.generateCertificate(inStream);
// check if valid on specific date (now set for today)
cert.checkValidity(new Date());
// Date nBefore = cert.getNotBefore();
// Date nAfter = cert.getNotAfter();
}
C++
using namespace System;
using namespace System::Security::Cryptography::X509Certificates;
int main()
{
// The path to the certificate.
String^ Certificate = "Certificate.cer";
// Load the certificate into an X509Certificate object.
X509Certificate^ cert = X509Certificate::CreateFromCertFile( Certificate );
// Get the value.
String^ results = cert->GetExpirationDateString();
// Display the value to the console.
Console::WriteLine( results );
}
C
X509 *x
time_t *ptime;
i=X509_cmp_time(X509_get_notBefore(x), ptime);
i=X509_cmp_time(X509_get_notAfter(x), ptime);

Answer 2

You should be able to use:
result=X509_cmp_time(X509_get_notBefore(cert), ptime);
and
result=X509_cmp_time(X509_get_notAfter(cert), ptime);
using OpenSSL. I'm not sure if you can get it less "manual" than that.