init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/X509/PemParser.cs

@@ -0,0 +1,74 @@
+using System.IO;
+using System.Text;
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.X509;
+
+internal 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)
+	{
+		StringBuilder stringBuilder = new StringBuilder();
+		int num;
+		while (true)
+		{
+			if ((num = inStream.ReadByte()) != 13 && num != 10 && num >= 0)
+			{
+				if (num != 13)
+				{
+					stringBuilder.Append((char)num);
+				}
+			}
+			else if (num < 0 || stringBuilder.Length != 0)
+			{
+				break;
+			}
+		}
+		if (num < 0)
+		{
+			return null;
+		}
+		return stringBuilder.ToString();
+	}
+
+	internal Asn1Sequence ReadPemObject(Stream inStream)
+	{
+		StringBuilder stringBuilder = new StringBuilder();
+		string source;
+		while ((source = ReadLine(inStream)) != null && !Platform.StartsWith(source, _header1) && !Platform.StartsWith(source, _header2))
+		{
+		}
+		while ((source = ReadLine(inStream)) != null && !Platform.StartsWith(source, _footer1) && !Platform.StartsWith(source, _footer2))
+		{
+			stringBuilder.Append(source);
+		}
+		if (stringBuilder.Length != 0)
+		{
+			Asn1Object asn1Object = Asn1Object.FromByteArray(Base64.Decode(stringBuilder.ToString()));
+			if (!(asn1Object is Asn1Sequence))
+			{
+				throw new IOException("malformed PEM data encountered");
+			}
+			return (Asn1Sequence)asn1Object;
+		}
+		return null;
+	}
+}