private static X509Certificate2[] LoadTrustedFile(string trustedFile)
{
// The TrustedFile is a file containing the public keys, in PEM format of the trusted
// root certificates that this client is willing to accept TLS connections from.
if (!string.IsNullOrWhiteSpace(trustedFile) && File.Exists(trustedFile))
{
try
{
var trustedRootCertificatesPem = File.ReadAllText(trustedFile, Encoding.ASCII);
var parser = new PemParser();
var rootCertificates =
parser.ParseCertificates(trustedRootCertificatesPem).ToArray();
return(rootCertificates);
}
catch (CryptographicException e)
{
throw new AseException("Failed to extract a public key from the TrustedFile.", e);
}
catch (Exception e) when(e is PathTooLongException || e is FileNotFoundException || e is DirectoryNotFoundException || e is UnauthorizedAccessException)
{
throw new AseException("Failed to open the TrustedFile.", e);
}
}
return(null);
}
private bool UserCertificateValidationCallback(object sender, X509Certificate serverCertificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
{
var certificateChainPolicyErrors = (sslPolicyErrors & SslPolicyErrors.RemoteCertificateChainErrors) == SslPolicyErrors.RemoteCertificateChainErrors;
var otherPolicyErrors = (sslPolicyErrors & ~SslPolicyErrors.RemoteCertificateChainErrors) != SslPolicyErrors.None;
// We're not concerned with chain errors as we verify the chain below.
if (otherPolicyErrors)
{
Logger.Instance?.WriteLine($"{nameof(InternalConnectionFactory)}.{nameof(UserCertificateValidationCallback)} secure connection failed due to policy errors: {sslPolicyErrors}");
return(false);
}
var untrustedRootChainStatusFlags = false;
var otherChainStatusFlags = false;
// We're not concerned with UntrustedRoot errors as we verify that below.
foreach (var status in chain.ChainStatus)
{
untrustedRootChainStatusFlags |= (status.Status & X509ChainStatusFlags.UntrustedRoot) == X509ChainStatusFlags.UntrustedRoot;
otherChainStatusFlags |= (status.Status & ~X509ChainStatusFlags.UntrustedRoot) != X509ChainStatusFlags.NoError;
if (otherChainStatusFlags)
{
Logger.Instance?.WriteLine($"{nameof(InternalConnectionFactory)}.{nameof(UserCertificateValidationCallback)} secure connection failed due to chain status: {status.Status}");
return(false);
}
}
if (!(certificateChainPolicyErrors || untrustedRootChainStatusFlags))
{
//No chain Errors, we will trust the server certificate.
return(true);
}
// The TrustedFile is a file containing the public keys, in PEM format of the trusted
// root certificates that this client is willing to accept TLS connections from.
if (!string.IsNullOrWhiteSpace(_parameters.TrustedFile) && File.Exists(_parameters.TrustedFile))
{
try
{
var trustedRootCertificatesPem = File.ReadAllText(_parameters.TrustedFile, Encoding.ASCII);
var parser = new PemParser();
var rootCertificates =
parser.ParseCertificates(trustedRootCertificatesPem)
.ToDictionary(GetCertificateKey);
// If the server certificate itself is the root, weird, but ok.
if (rootCertificates.ContainsKey(GetCertificateKey(serverCertificate)))
{
return(true);
}
// If any certificates in the chain are trusted, then we will trust the server certificate.
foreach (var chainElement in chain.ChainElements)
{
var key = GetCertificateKey(chainElement.Certificate);
if (rootCertificates.ContainsKey(key))
{
return(true);
}
}
}
catch (CryptographicException e)
{
throw new AseException("Failed to extract a public key from the TrustedFile.", e);
}
catch (Exception e) when(e is PathTooLongException || e is FileNotFoundException || e is DirectoryNotFoundException || e is UnauthorizedAccessException)
{
throw new AseException("Failed to open the TrustedFile.", e);
}
}
Logger.Instance?.WriteLine($"{nameof(InternalConnectionFactory)}.{nameof(UserCertificateValidationCallback)} secure connection failed due to missing root or intermediate certificate in the certificate store, or the TrustedFile.");
return(false);
}