Gendarme.Rules.Security.DoNotShortCircuitCertificateCheckRule(2.10)

DoNotShortCircuitCertificateCheckRule

Assembly: Gendarme.Rules.Security
Version: 2.10

Description

This rule checks for methods that implements pass-through certificate checks. I.e. methods that override the framework decision about a certificate validity without checking anything specific about the supplied certificate or error code. Protocols like TLS/SSL are only secure if the certificates are used correctly.

Examples

Bad example (ICertificatePolicy):

public class AcceptEverythingCertificatePolicy : ICertificatePolicy {
    public bool CheckValidationResult (ServicePoint srvPoint, X509Certificate certificate, WebRequest request, int certificateProblem)
    {
        // this accepts everything making it easy for MITM
        // (Man-in-the-middle) attacks
        return true;
    }
}

Good example (ICertificatePolicy):

public class AllowSpecificCertificatePolicy : ICertificatePolicy {
    public bool CheckValidationResult (ServicePoint srvPoint, X509Certificate certificate, WebRequest request, int certificateProblem)
    {
        // this accept only a specific certificate, even if others would be ok
        return (certificate.GetCertHashString () == "D62F48D013EE7FB58B79074512670D9C5B3A5DA9");
    }
}

Bad example (RemoteCertificateValidationCallback):

public bool CertificateValidationCallback (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
{
    // this accepts everything making it easy for MITM
    // (Man-in-the-middle) attacks
    return true;
}
SslStream ssl = new SslStream (stream, false, new RemoteCertificateValidationCallback (CertificateValidationCallback), null);

Good example (RemoteCertificateValidationCallback):

public bool CertificateValidationCallback (object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
{
    // this accept only a specific certificate, even if others would be ok
    return (certificate.GetCertHashString () == "D62F48D013EE7FB58B79074512670D9C5B3A5DA9");
}
SslStream ssl = new SslStream (stream, false, new RemoteCertificateValidationCallback (CertificateValidationCallback), null);

Notes

• This rule is available since Gendarme 2.4