How do I return a base64 encoded string given a string?
How do I decode a base64 encoded string into a string?
You can use below routine to convert string to base64 format
public static string ToBase64(string s)
{
byte[] buffer = System.Text.Encoding.Unicode.GetBytes(s);
return System.Convert.ToBase64String(buffer);
}
Also you can use very good online tool OnlineUtility.in to encode string in base64 format
A slight variation on andrew.fox answer, as the string to decode might not be a correct base64 encoded string:
using System;
namespace Service.Support
{
public static class Base64
{
public static string ToBase64(this System.Text.Encoding encoding, string text)
{
if (text == null)
{
return null;
}
byte[] textAsBytes = encoding.GetBytes(text);
return Convert.ToBase64String(textAsBytes);
}
public static bool TryParseBase64(this System.Text.Encoding encoding, string encodedText, out string decodedText)
{
if (encodedText == null)
{
decodedText = null;
return false;
}
try
{
byte[] textAsBytes = Convert.FromBase64String(encodedText);
decodedText = encoding.GetString(textAsBytes);
return true;
}
catch (Exception)
{
decodedText = null;
return false;
}
}
}
}
Based on the answers by Andrew Fox and Cebe, I turned it around and made them string extensions instead of Base64String extensions.
public static class StringExtensions
{
public static string ToBase64(this string text)
{
return ToBase64(text, Encoding.UTF8);
}
public static string ToBase64(this string text, Encoding encoding)
{
if (string.IsNullOrEmpty(text))
{
return text;
}
byte[] textAsBytes = encoding.GetBytes(text);
return Convert.ToBase64String(textAsBytes);
}
public static bool TryParseBase64(this string text, out string decodedText)
{
return TryParseBase64(text, Encoding.UTF8, out decodedText);
}
public static bool TryParseBase64(this string text, Encoding encoding, out string decodedText)
{
if (string.IsNullOrEmpty(text))
{
decodedText = text;
return false;
}
try
{
byte[] textAsBytes = Convert.FromBase64String(text);
decodedText = encoding.GetString(textAsBytes);
return true;
}
catch (Exception)
{
decodedText = null;
return false;
}
}
}
using System;
using System.Text;
public static class Base64Conversions
{
public static string EncodeBase64(this string text, Encoding encoding = null)
{
if (text == null) return null;
encoding = encoding ?? Encoding.UTF8;
var bytes = encoding.GetBytes(text);
return Convert.ToBase64String(bytes);
}
public static string DecodeBase64(this string encodedText, Encoding encoding = null)
{
if (encodedText == null) return null;
encoding = encoding ?? Encoding.UTF8;
var bytes = Convert.FromBase64String(encodedText);
return encoding.GetString(bytes);
}
}
Usage
var text = "Sample Text";
var base64 = text.EncodeBase64();
base64 = text.EncodeBase64(Encoding.UTF8); //or with Encoding
For those that simply want to encode/decode individual base64 digits:
public static int DecodeBase64Digit(char digit, string digit62 = "+-.~", string digit63 = "/_,")
{
if (digit >= 'A' && digit <= 'Z') return digit - 'A';
if (digit >= 'a' && digit <= 'z') return digit + (26 - 'a');
if (digit >= '0' && digit <= '9') return digit + (52 - '0');
if (digit62.IndexOf(digit) > -1) return 62;
if (digit63.IndexOf(digit) > -1) return 63;
return -1;
}
public static char EncodeBase64Digit(int digit, char digit62 = '+', char digit63 = '/')
{
digit &= 63;
if (digit < 52)
return (char)(digit < 26 ? digit + 'A' : digit + ('a' - 26));
else if (digit < 62)
return (char)(digit + ('0' - 52));
else
return digit == 62 ? digit62 : digit63;
}
There are various versions of Base64 that disagree about what to use for digits 62 and 63, so DecodeBase64Digit
can tolerate several of these.
URL safe Base64 Encoding/Decoding
public static class Base64Url
{
public static string Encode(string text)
{
return Convert.ToBase64String(Encoding.UTF8.GetBytes(text)).TrimEnd('=').Replace('+', '-')
.Replace('/', '_');
}
public static string Decode(string text)
{
text = text.Replace('_', '/').Replace('-', '+');
switch (text.Length % 4)
{
case 2:
text += "==";
break;
case 3:
text += "=";
break;
}
return Encoding.UTF8.GetString(Convert.FromBase64String(text));
}
}