HMAC SHA256 in .NET .1.1

Question

I have to dare with a web application developed in .NET 1.1 Framework , with no possibilities to upgrade to major versions.

Having said that, I need to encrypt a text using HMAC SHA256 .

I see that System.Security.Cryptography namespace in .NET 1.1 provides me a way to has a message in SHA256. But I need to use HMAC (Hash-based Message Authentication Code) with SHA256, so I send not only the text to encrypt, but also a key .

I see that .NET Framework 2.0 and later has an specific class HMACSHA256 to manage this. But haven't found an implementation for .NET 1.1.

¿Any help?

Thanks in advance

Answer 1

You can add to your project the file from Microsoft :

namespace System.Security.Cryptography {
    [System.Runtime.InteropServices.ComVisible(true)]
    public class HMACSHA256 : HMAC {
        //
        // public constructors
        //

        public HMACSHA256 () : this (Utils.GenerateRandom(64)) {}

        public HMACSHA256 (byte[] key) {
            m_hashName = "SHA256";

#if FEATURE_CRYPTO
            m_hash1 = GetHashAlgorithmWithFipsFallback(() => new SHA256Managed(), () => HashAlgorithm.Create("System.Security.Cryptography.SHA256CryptoServiceProvider"));
            m_hash2 = GetHashAlgorithmWithFipsFallback(() => new SHA256Managed(), () => HashAlgorithm.Create("System.Security.Cryptography.SHA256CryptoServiceProvider"));
#else
            m_hash1 = new SHA256Managed();
            m_hash2 = new SHA256Managed();
#endif // FEATURE_CRYPTO

            HashSizeValue = 256;
            base.InitializeKey(key);
        }
    }
}

It seems that all calls are based on class that exists in .Net 1.1