[openssl-users] C# OpenSSL openssl-net-master - OpenSSL Server malfunction

Hegazi, Amr Amr.Hegazi at vector.com
Wed Jul 26 14:06:47 UTC 2017

Hello *,

Even if no one know what to do, has anyone ever used OpenSSL Server? and if so, is there any configuration parameters that I should take care of in case of OpenSSL Server?

I hope to hear positive response from you guys.

Best Regards,


From: Hegazi, Amr
Sent: Tuesday, July 25, 2017 6:50 PM
To: 'openssl-users at openssl.org'
Subject: Considering C# OpenSSL openssl-net-master

Hello *,

I'm using the last version of C# OpenSSL from https://github.com/openssl-net/openssl-net (This wrapper is based on version 1.0.2a of libeay32.dll and ssleay32.dll).

I'm using C# OpenSSL to test my Tls Client that supports TLS starting from version 1.2 and all the cipher suites. Moreover, I'm using Microsoft windows 7. I have already installed Microsoft visual C++ 2010 express and Microsoft visual Studio 2010.

I always face an error "TLSv1.2  81 - Alert (Level: Fatal, Description: Insufficient Security)"

I have debugged the issue. The issue come from a function called SSL_CTX_new() which is connected to ssleay32.dll. the clienthello is always sent correctly and then the OpenSSL server replies with Insufficient Security

The console also shows this:
.NET   HSM Received: ClientHello (188 bytes)
.NET   Offered suite by client: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b) [not supported]
.NET   Offered suite by client: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (0xc023) [not supported]
.NET   Offered suite by client: TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 (0xc025) [not supported]
.NET   Offered suite by client: TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009) [not supported]
.NET   Offered suite by client: TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA (0xc004) [not supported]
.NET   Offered suite by client: TLS_RSA_WITH_AES_128_CBC_SHA256 (0x003c) [not supported]
.NET   Offered suite by client: TLS_RSA_WITH_AES_128_CBC_SHA (0x002f) [not supported]
.NET   Offered suite by client: TLS_ECDH_ECDSA_WITH_NULL_SHA (0xc001) [not supported]
.NET   Offered suite by client: TLS_RSA_WITH_NULL_SHA256 (0x003b) [not supported]
.NET   Offered suite by client: TLS_RSA_WITH_NULL_SHA (0x0002) [not supported]
.NET   ALERT SENT    : Fatal InsufficientSecurity
.NET   no shared cipher suites

And in Wireshark shows this:

"3406.315537","fe80::ff:fe00:2","fe80::1:5","SSL","271","Client Hello"
"3419.805155","fe80::1:5","fe80::ff:fe00:2","TLSv1.2","81","Alert (Level: Fatal, Description: Insufficient Security)"

So, I think the error is in something related to configuration of ssleay32.dll

My code is simple and is as follows:


            Output.WriteLine("TLS Server Certificate preparation");
            CertDir = Path.GetFullPath("..\\Appl\\Certificates\\Certificate");
TlsServerCertificate = loadCertificateFromFile(Path.Combine(CertDir, @"Vector_ServerCertificate_RsaSha1_IA_pfx.pfx"), "123456");
TlsServerCaCertificates = new X509Chain(OpenSSL.Core.BIO.File(Path.Combine(CertDir, @"Vector_ServerCertificate_RsaSha1_Root_cert.cer"), "r"));

            Output.WriteLine("Start connection");

            Output.WriteLine("Send Client Hello");

            Output.WriteLine("make sslStreamServer");
SslStream sslStreamServer = new SslStream(tcpClient.GetStream(), true, MyRemoteCertificateValidationHandler,MyLocalCertificateSelectionHandler);

Output.WriteLine("Start AuthenticateAsServer");

sslStreamServer.AuthenticateAsServer(TlsServerCertificate, false, TlsServerCaCertificates, SslProtocols.Tls, SslStrength.All, false);

        catch (TestStepFailException e)
       catch (Exception ex)

Has anyone an idea?

Best Regards;


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