1 files changed, 69 insertions, 0 deletions
diff --git a/crypto/src/tls/TlsSrpUtilities.cs b/crypto/src/tls/TlsSrpUtilities.cs
new file mode 100644
index 000000000..c36a667ac
--- /dev/null
+++ b/crypto/src/tls/TlsSrpUtilities.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Collections;
+using System.IO;
+
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Tls
+{
+    public abstract class TlsSrpUtilities
+    {
+        /// <exception cref="IOException"/>
+        public static void AddSrpExtension(IDictionary extensions, byte[] identity)
+        {
+            extensions[ExtensionType.srp] = CreateSrpExtension(identity);
+        }
+
+        /// <exception cref="IOException"/>
+        public static byte[] GetSrpExtension(IDictionary extensions)
+        {
+            byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.srp);
+            return extensionData == null ? null : ReadSrpExtension(extensionData);
+        }
+
+        /// <exception cref="IOException"/>
+        public static byte[] CreateSrpExtension(byte[] identity)
+        {
+            if (identity == null)
+                throw new TlsFatalAlert(AlertDescription.internal_error);
+
+            return TlsUtilities.EncodeOpaque8(identity);
+        }
+
+        /// <exception cref="IOException"/>
+        public static byte[] ReadSrpExtension(byte[] extensionData)
+        {
+            if (extensionData == null)
+                throw new ArgumentNullException("extensionData");
+
+            return TlsUtilities.DecodeOpaque8(extensionData, 1);
+        }
+
+        /// <exception cref="IOException"/>
+        public static BigInteger ReadSrpParameter(Stream input)
+        {
+            return new BigInteger(1, TlsUtilities.ReadOpaque16(input, 1));
+        }
+
+        /// <exception cref="IOException"/>
+        public static void WriteSrpParameter(BigInteger x, Stream output)
+        {
+            TlsUtilities.WriteOpaque16(BigIntegers.AsUnsignedByteArray(x), output);
+        }
+
+        public static bool IsSrpCipherSuite(int cipherSuite)
+        {
+            switch (TlsUtilities.GetKeyExchangeAlgorithm(cipherSuite))
+            {
+            case KeyExchangeAlgorithm.SRP:
+            case KeyExchangeAlgorithm.SRP_DSS:
+            case KeyExchangeAlgorithm.SRP_RSA:
+                return true;
+
+            default:
+                return false;
+            }
+        }
+    }
+}