A managed OpenSSL wrapper written in C# targeting the .NET Framework 3.5. It exposes both the Crypto API and the SSL API.

This is a must for .NET developers that need crypto but don't want to use Microsoft's SSPI. The wrapper is based on version 1.0.2k of libeay32.dlland ssleay32.dll. Both the 32 Bit and 64 Bit versions of these DLLs are provided as 3PP in the native directory and have been taken from:

https://indy.fulgan.com/SSL/openssl-1.0.2k-i386-win32.zip

https://indy.fulgan.com/SSL/openssl-1.0.2k-x64_86-win64.zip

as suggested in the OpenSSL Wiki.

The following differences compared to OpenSSL.net apply:

• backported project & solution files for Visual Studio 2008
• new project & solution files for Visual Studio 2015
• CLI project has been dropped
• no unit tests + drop of related packages
• add missing wrapper for RSA_verify() function

The following is a partial example to show the general pattern of wrapping onto the C API.

Take DSA and the following C prototypes:

DSA *  DSA_new(void);
void   DSA_free(DSA *dsa);
int    DSA_size(const DSA *dsa);
int    DSA_generate_key(DSA *dsa);
int    DSA_sign(int dummy, const unsigned char *dgst, int len,
                unsigned char *sigret, unsigned int *siglen, DSA *dsa);
int    DSA_verify(int dummy, const unsigned char *dgst, int len,
                const unsigned char *sigbuf, int siglen, DSA *dsa);

Which gets wrapped as something akin to:

public class DSA : IDisposable
{
    // calls DSA_new()
    public DSA();

    // calls DSA_free() as needed
    ~DSA();

    // calls DSA_free() as needed
    public void Dispose();

    // returns DSA_size()
    public int Size { get; }

    // calls DSA_generate_key()
    public void GenerateKeys();

    // calls DSA_sign()
    public byte[] Sign(byte[] msg);

    // returns DSA_verify()
    public bool Verify(byte[] msg, byte[] sig);
}

The binary package contains the ManagedOpenSsl.dll pre-compiled with VS 2015 and "Any CPU" platform. Both libeay32.dll and ssleay32.dll are statically linked native C DLLs without external dependencies. Hence you just have to make sure both libeay32.dll and ssleay32.dll are either located in the current working directory of your application or accessible by the PATH environment variable.

In your .NET project, add a reference to the ManagedOpenSsl.dll assembly.

If you're having trouble with the native library being loaded under mono, try using MONO_LOG_LEVEL=debug when invoking mono.

Take a look at the low-level C API documentation.

This repository contains two software components with dedicated licenses:

• The underlying, native OpenSSL libraries (only contained as binaries) are distributed under the terms of the OpenSSL License & SSLeay License
• The ManagedOpenSSL library and related code are released under the original OpenSSL.net license, which is a BSD license. For more details see LICENSE