1 files changed, 94 insertions, 0 deletions
diff --git a/Crypto/src/x509/PEMParser.cs b/Crypto/src/x509/PEMParser.cs
new file mode 100644
index 000000000..8c117f323
--- /dev/null
+++ b/Crypto/src/x509/PEMParser.cs
@@ -0,0 +1,94 @@
+using System;
+using System.IO;
+using System.Text;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.X509
+{
+	class PemParser
+	{
+		private readonly string _header1;
+		private readonly string _header2;
+		private readonly string _footer1;
+		private readonly string _footer2;
+
+		internal PemParser(
+			string type)
+		{
+			_header1 = "-----BEGIN " + type + "-----";
+			_header2 = "-----BEGIN X509 " + type + "-----";
+			_footer1 = "-----END " + type + "-----";
+			_footer2 = "-----END X509 " + type + "-----";
+		}
+
+		private string ReadLine(
+			Stream inStream)
+		{
+			int c;
+			StringBuilder l = new StringBuilder();
+
+			do
+			{
+				while (((c = inStream.ReadByte()) != '\r') && c != '\n' && (c >= 0))
+				{
+					if (c == '\r')
+					{
+						continue;
+					}
+
+					l.Append((char)c);
+				}
+			}
+			while (c >= 0 && l.Length == 0);
+
+			if (c < 0)
+			{
+				return null;
+			}
+
+			return l.ToString();
+		}
+
+		internal Asn1Sequence ReadPemObject(
+			Stream inStream)
+		{
+			string line;
+			StringBuilder pemBuf = new StringBuilder();
+
+			while ((line = ReadLine(inStream)) != null)
+			{
+				if (line.StartsWith(_header1) || line.StartsWith(_header2))
+				{
+					break;
+				}
+			}
+
+			while ((line = ReadLine(inStream)) != null)
+			{
+				if (line.StartsWith(_footer1) || line.StartsWith(_footer2))
+				{
+					break;
+				}
+
+				pemBuf.Append(line);
+			}
+
+			if (pemBuf.Length != 0)
+			{
+				Asn1Object o = Asn1Object.FromByteArray(Base64.Decode(pemBuf.ToString()));
+
+				if (!(o is Asn1Sequence))
+				{
+					throw new IOException("malformed PEM data encountered");
+				}
+
+				return (Asn1Sequence) o;
+			}
+
+			return null;
+		}
+	}
+}
+