An exception occured in certificate verifier for SSL Mode Implicit

Question

Hello,

My code is:

Ftp ftp = new Ftp();
ftp.Connect(host, 990, SslMode.Implicit);
ftp.Login(user, password);

I use the 4.0 library. I get the following exception when I try to connect:

"An exception occured in certificate verifier."
   at gbMKS.QsaHcZ.1GG6Jr(String , CertificateChain )
   at gbMKS.QsaHcZ.RYVUe(Byte[] , Int32 , Int32 , 1RjReZZ )
   at gbMKS.QsaHcZ.OnHandshakeReceived(Byte[] buffer, Int32 offset, Int32 count)
   at gbMKS.1UaphuZ.2YjOc(Byte[] , Int32 , Int32 )
   at gbMKS.1UaphuZ.1rsOcLZ()
Inner Exception:
"Object reference not set to an instance of an object."
   at Rebex.Security.Certificates.CertificateChain.17JPqSZ(String , String )
   at Rebex.Security.Certificates.CertificateChain.T2SEsZ(CertificateChainEngine , Certificate , CertificateStore , String , ValidationOptions )
   at Rebex.Security.Certificates.CertificateChain.Validate(String serverName, ValidationOptions options, CertificateChainEngine engine)
   at Rebex.Security.Certificates.CertificateChain.Validate(String serverName, ValidationOptions options)
   at Rebex.Net.CertificateVerifier.1nrbFGZ.Verify(TlsSocket socket, String commonName, CertificateChain certificateChain)
   at gbMKS.1xpVSY.Verify(TlsSocket socket, String commonName, CertificateChain certificateChain)
   at gbMKS.QsaHcZ.1GG6Jr(String , CertificateChain )

Do you know what I'm doing wrong? Thanks

Comments

This looks like a bug in the certificate validation routine, possibly related to something unusual in the certificate structure. We will fix it and let you know. Thanks for reporting this!

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In the meantime, you can work around this issue using a custom certificate verifier - see http://www.rebex.net/support/tutorial/ftp-ssl/default.aspx#validating-and-examining-server-certificates for more information.

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I have sent the link to our hotfix release to your e-mail.

Answer 1

It looks like the problem was caused by a bug in a certificate's common name checking routine. Please try the hotfix Frantisek sent you and let me know whether it solves the issue. It is possible that a different exception will be thrown instead, containing a more meaningful error message - please let me know in this case as well. Thanks!