1 files changed, 83 insertions, 0 deletions
diff --git a/crypto/src/util/ssh/SSHBuilder.cs b/crypto/src/util/ssh/SSHBuilder.cs
new file mode 100644
index 000000000..5fa92de4b
--- /dev/null
+++ b/crypto/src/util/ssh/SSHBuilder.cs
@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Org.BouncyCastle.Math;
+
+namespace Org.BouncyCastle.Utilities.SSH
+{
+    public class SSHBuilder
+    {
+        private readonly MemoryStream bos = new MemoryStream();
+
+        [CLSCompliant(false)]
+        public void U32(uint value)
+        {
+            bos.WriteByte(Convert.ToByte((value >> 24) & 0xFF));
+            bos.WriteByte(Convert.ToByte((value >> 16) & 0xFF));
+            bos.WriteByte(Convert.ToByte((value >> 8) & 0xFF));
+            bos.WriteByte(Convert.ToByte(value & 0xFF));
+        }
+
+        public void WriteBigNum(BigInteger n)
+        {
+            WriteBlock(n.ToByteArray());
+        }
+
+        public void WriteBlock(byte[] value)
+        {
+            U32((uint)value.Length);
+            try
+            {
+                bos.Write(value, 0, value.Length);
+            }
+            catch (IOException e)
+            {
+                throw new InvalidOperationException(e.Message, e);
+            }
+        }
+
+        public void WriteBytes(byte[] value)
+        {
+            try
+            {
+                bos.Write(value, 0, value.Length);
+            }
+            catch (IOException e)
+            {
+                throw new InvalidOperationException(e.Message, e);
+            }
+        }
+
+        public void WriteString(String str)
+        {
+            WriteBlock(Strings.ToByteArray(str));
+        }
+
+        public byte[] GetBytes()
+        {
+            return bos.ToArray();
+        }
+
+        public byte[] GetPaddedBytes()
+        {
+            return GetPaddedBytes(8);
+        }
+
+        public byte[] GetPaddedBytes(int blockSize)
+        {
+            int align = (int)bos.Length % blockSize;
+            if (0 != align)
+            {
+                int padCount = blockSize - align;
+                for (int i = 1; i <= padCount; ++i)
+                {
+                    bos.WriteByte(Convert.ToByte(i));
+                }
+            }
+            return bos.ToArray();
+        }
+    }
+}