EmailUrlObfuscation

EmailUrlObfuscation.cs

using System;
using System.Text;
using System.Linq;

public static class EmailUrlObfuscation
{
    private static string AtSymbolEncode(this string email) => email
        .Replace("]", "-]")
        .Replace("@", "[a]");

    private static string AtSymbolDecode(this string customizedEmail) => customizedEmail
        .Replace("[a]", "@")
        .Replace("-]", "]");

    private static string Base64Encode(this string plain) =>
        Convert.ToBase64String(Encoding.UTF8.GetBytes(plain));

    private static string Base64Decode(this string base64) =>
        Encoding.UTF8.GetString(Convert.FromBase64String(base64));

    private static string Base64ForUrlEncode(this string base64) => base64
        .Replace('+', '-')
        .Replace('/', '_')
        .TrimEnd(new[] { '=' });

    private static string Base64ForUrlDecode(this string base64ForUrl) => base64ForUrl
        .Replace('-', '+')
        .Replace('_', '/')
        + string.Join("", Enumerable.Repeat("=", (4 - base64ForUrl.Length % 4) % 4));

    public static string ObfuscateEmailForUrl(string email) => email
        .AtSymbolEncode()
        .Base64Encode()
        .Base64ForUrlEncode();

    public static string DeobfuscateEmailForUrl(string obfuscatedEmail) => obfuscatedEmail
        .Base64ForUrlDecode()
        .Base64Decode()
        .AtSymbolDecode();
}