SXprUtilities
using Org.BouncyCastle.Utilities.IO;
using System;
using System.IO;
namespace Org.BouncyCastle.Bcpg.OpenPgp
{
public sealed class SXprUtilities
{
private class MyS2k : S2k
{
private readonly long m_iterationCount64;
public override long IterationCount => m_iterationCount64;
internal MyS2k(HashAlgorithmTag algorithm, byte[] iv, long iterationCount64)
: base(algorithm, iv, (int)iterationCount64)
{
m_iterationCount64 = iterationCount64;
}
}
private SXprUtilities()
{
}
private static int ReadLength(Stream input, int ch)
{
int num = ch - 48;
while ((ch = input.ReadByte()) >= 0 && ch != 58) {
num = num * 10 + ch - 48;
}
return num;
}
internal static string ReadString(Stream input, int ch)
{
return string.Create(ReadLength(input, ch), input, delegate(Span<char> chars, Stream input) {
for (int i = 0; i < chars.Length; i++) {
chars[i] = Convert.ToChar(input.ReadByte());
}
});
}
internal static byte[] ReadBytes(Stream input, int ch)
{
int num = ReadLength(input, ch);
byte[] array = new byte[num];
if (num != Streams.ReadFully(input, array))
throw new EndOfStreamException();
return array;
}
internal static S2k ParseS2k(Stream input)
{
SkipOpenParenthesis(input);
ReadString(input, input.ReadByte());
byte[] iv = ReadBytes(input, input.ReadByte());
long iterationCount = long.Parse(ReadString(input, input.ReadByte()));
SkipCloseParenthesis(input);
return new MyS2k(HashAlgorithmTag.Sha1, iv, iterationCount);
}
internal static void SkipOpenParenthesis(Stream input)
{
int num = input.ReadByte();
if (num != 40)
throw new IOException("unknown character encountered: " + Convert.ToChar(num).ToString());
}
internal static void SkipCloseParenthesis(Stream input)
{
int num = input.ReadByte();
if (num != 41)
throw new IOException("unknown character encountered: " + Convert.ToChar(num).ToString());
}
}
}