1 files changed, 49 insertions, 0 deletions
diff --git a/crypto/src/crypto/agreement/srp/SRP6VerifierGenerator.cs b/crypto/src/crypto/agreement/srp/SRP6VerifierGenerator.cs
new file mode 100644
index 000000000..264833b4d
--- /dev/null
+++ b/crypto/src/crypto/agreement/srp/SRP6VerifierGenerator.cs
@@ -0,0 +1,49 @@
+using System;
+
+using Org.BouncyCastle.Math;
+
+namespace Org.BouncyCastle.Crypto.Agreement.Srp
+{
+	/**
+	 * Generates new SRP verifier for user
+	 */
+	public class Srp6VerifierGenerator
+	{
+	    protected BigInteger N;
+	    protected BigInteger g;
+	    protected IDigest digest;
+
+	    public Srp6VerifierGenerator()
+	    {
+	    }
+
+	    /**
+	     * Initialises generator to create new verifiers
+	     * @param N The safe prime to use (see DHParametersGenerator)
+	     * @param g The group parameter to use (see DHParametersGenerator)
+	     * @param digest The digest to use. The same digest type will need to be used later for the actual authentication
+	     * attempt. Also note that the final session key size is dependent on the chosen digest.
+	     */
+	    public virtual void Init(BigInteger N, BigInteger g, IDigest digest)
+	    {
+	        this.N = N;
+	        this.g = g;
+	        this.digest = digest;
+	    }
+
+	    /**
+	     * Creates a new SRP verifier
+	     * @param salt The salt to use, generally should be large and random
+	     * @param identity The user's identifying information (eg. username)
+	     * @param password The user's password
+	     * @return A new verifier for use in future SRP authentication
+	     */
+	    public virtual BigInteger GenerateVerifier(byte[] salt, byte[] identity, byte[] password)
+	    {
+	    	BigInteger x = Srp6Utilities.CalculateX(digest, N, salt, identity, password);
+
+	        return g.ModPow(x, N);
+	    }
+	}
+}
+