1 files changed, 120 insertions, 0 deletions
diff --git a/Crypto/src/util/io/pem/PemWriter.cs b/Crypto/src/util/io/pem/PemWriter.cs
new file mode 100644
index 000000000..e85b31543
--- /dev/null
+++ b/Crypto/src/util/io/pem/PemWriter.cs
@@ -0,0 +1,120 @@
+using System;
+using System.Collections;
+using System.IO;
+
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Utilities.IO.Pem
+{
+	/**
+	* A generic PEM writer, based on RFC 1421
+	*/
+	public class PemWriter
+	{
+		private const int LineLength = 64;
+
+		private readonly TextWriter	writer;
+		private readonly int		nlLength;
+		private char[]				buf = new char[LineLength];
+		
+		/**
+		 * Base constructor.
+		 *
+		 * @param out output stream to use.
+		 */
+		public PemWriter(TextWriter writer)
+		{
+			if (writer == null)
+				throw new ArgumentNullException("writer");
+
+			this.writer = writer;
+			this.nlLength = Platform.NewLine.Length;
+		}
+
+		public TextWriter Writer
+		{
+			get { return writer; }
+		}
+
+		/**
+		 * Return the number of bytes or characters required to contain the
+		 * passed in object if it is PEM encoded.
+		 *
+		 * @param obj pem object to be output
+		 * @return an estimate of the number of bytes
+		 */
+		public int GetOutputSize(PemObject obj)
+		{
+			// BEGIN and END boundaries.
+			int size = (2 * (obj.Type.Length + 10 + nlLength)) + 6 + 4;
+
+			if (obj.Headers.Count > 0)
+			{
+				foreach (PemHeader header in obj.Headers)
+				{
+					size += header.Name.Length + ": ".Length + header.Value.Length + nlLength;
+				}
+
+				size += nlLength;
+			}
+
+			// base64 encoding
+			int dataLen = ((obj.Content.Length + 2) / 3) * 4;
+
+			size += dataLen + (((dataLen + LineLength - 1) / LineLength) * nlLength);
+
+			return size;
+		}
+
+		public void WriteObject(PemObjectGenerator objGen)
+		{
+			PemObject obj = objGen.Generate();
+
+			WritePreEncapsulationBoundary(obj.Type);
+
+			if (obj.Headers.Count > 0)
+			{
+				foreach (PemHeader header in obj.Headers)
+				{
+					writer.Write(header.Name);
+					writer.Write(": ");
+					writer.WriteLine(header.Value);
+				}
+
+				writer.WriteLine();
+			}
+
+			WriteEncoded(obj.Content);
+			WritePostEncapsulationBoundary(obj.Type);
+		}
+
+		private void WriteEncoded(byte[] bytes)
+		{
+			bytes = Base64.Encode(bytes);
+
+			for (int i = 0; i < bytes.Length; i += buf.Length)
+			{
+				int index = 0;
+				while (index != buf.Length)
+				{
+					if ((i + index) >= bytes.Length)
+						break;
+
+					buf[index] = (char)bytes[i + index];
+					index++;
+				}
+				writer.WriteLine(buf, 0, index);
+			}
+		}
+
+		private void WritePreEncapsulationBoundary(string type)
+		{
+			writer.WriteLine("-----BEGIN " + type + "-----");
+		}
+
+		private void WritePostEncapsulationBoundary(string type)
+		{
+			writer.WriteLine("-----END " + type + "-----");
+		}
+	}
+}