SHA1

[System.Runtime.InteropServices.ComVisible(true)]
public abstract class SHA1 : HashAlgorithm
{
    protected SHA1()
    {
        HashSizeValue = 160;
    }

    new static public SHA1 Create()
    {
        return Create("System.Security.Cryptography.SHA1");
    }

    new static public SHA1 Create(String hashName)
    {
        return (SHA1)CryptoConfig.CreateFromName(hashName);
    }
}



[System.Runtime.InteropServices.ComVisible(true)]
public class SHA1Managed : SHA1
{
    public SHA1Managed()
    {
#if FEATURE_CRYPTO
            if (CryptoConfig.AllowOnlyFipsAlgorithms)
                throw new InvalidOperationException(Environment.GetResourceString("Cryptography_NonCompliantFIPSAlgorithm"));
            Contract.EndContractBlock();
#endif // FEATURE_CRYPTO

        _stateSHA1 = new uint[5];
        _buffer = new byte[64];
        _expandedBuffer = new uint[80];

        InitializeState();
    }
}



[System.Security.Permissions.HostProtection(MayLeakOnAbort = true)]
public sealed class SHA1Cng : SHA1
{
    private BCryptHashAlgorithm m_hashAlgorithm;

    public SHA1Cng()
    {
        Contract.Ensures(m_hashAlgorithm != null);

        m_hashAlgorithm = new BCryptHashAlgorithm(CngAlgorithm.Sha1, BCryptNative.ProviderName.MicrosoftPrimitiveProvider);
    }

    protected override void Dispose(bool disposing)
    {
        try
        {
            if (disposing)
            {
                m_hashAlgorithm.Dispose();
            }
        }
        finally
        {
            base.Dispose(disposing);
        }
    }
}