using System;

namespace LogicSoftware.WebPushEncryption

{

class WebEncoder

{

public static byte[] Base64UrlDecode(string val)

{

string s = val;

s = s.Replace('-', '+'); // 62nd char of encoding

s = s.Replace('_', '/'); // 63rd char of encoding

switch (s.Length % 4) // Pad with trailing '='s

{

case 0: break; // No pad chars in this case

case 2: s += "=="; break; // Two pad chars

case 3: s += "="; break; // One pad char

default:

throw new System.Exception(

"Illegal base64url string!");

}

return Convert.FromBase64String(s); // Standard base64 decoder

}

public static string Base64UrlEncode(byte[] val)

{

string s = Convert.ToBase64String(val); // Regular base64 encoder

s = s.Split('=')[0]; // Remove any trailing '='s

s = s.Replace('+', '-'); // 62nd char of encoding

s = s.Replace('/', '_'); // 63rd char of encoding

return s;

}

}

}