Base64, Base32 and Base16 encodings in .NET

BaseN encoding

BaseN encodings are used to encode binary data into text. Where N is the size of the text alphabet used for encoding. BaseN encodings are used to "prepare data" for transmission via text protocols (HTTP, SMTP) or non-digital channels (eg printing on paper).

The most popular variant of this encoding is Base64 . Only Base16 known as hexadecimal or simply hex can be compared in frequency of use . Tools for working with them have been in .NET since the first versions, but they are not very convenient.

What's in the .NET Framework (Core)

System.Security.Cryptography

ToBase64Transform / FromBase64Transform

A couple of classes to convert to / from Base64. Using the CryptoStream helper class, it can be used to stream process Stream.

using System.Security.Cryptography;

var base64Transform = new ToBase64Transform();
var output = new MemoryStream();
var base64Encoder = new CryptoStream(output, base64Transform, CryptoStreamMode.Write);

base64Encoder.Write(new byte[] { 122 }, 0, 1);
base64Encoder.Close();
// output.ToArray() -> byte[4] { 101, 103, 61, 61 } aka "eg=="

      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

System.Convert

ToBase64String / FromBase64String

A couple of functions to convert an array of bytes to a Base64 string and back.

using System;

var bytes = System.Convert.FromBase64String("eg==")
// bytes -> 122
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

System.BitConverter

BitConverter.ToString

A function to convert an array of bytes to a Base16 (hexadecimal) string, where each byte is separated by a hyphen. Example: 0A-C0-D3

using System;

var hexString = BitConverter.ToString(new byte[] { 122, 122 });
// hexString -> "7A-7A"
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

System.Runtime.Remoting.Metadata.W3cXsd2001

SoapHexBinary (Framework-only)

A class that allows you to convert an array of bytes to a Base16 (hexadecimal) string and back.

using System.Runtime.Remoting.Metadata.W3cXsd2001;

var result = SoapHexBinary.Parse("A012");
// result.Value -> byte[];
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

System.Buffers.Text

Base64 (Core or System.Memory package)

Base64 . Span' Span .

Nuget

Multiformats.Base - Base2, 8, 16, 32, 58, 64 (+variants), MIT

BaseN . API . : .

SimpleBase - Base16, 32, 58, 85 (+variants), streaming, span, Apache-2

BaseN . .NET Core Span'. API, .

deniszykov.BaseN

.

, .NET Framework 4.5.

, Base64 Span<byte> to Span<byte> ( char[] <-> byte[] ). , . "" byte char , char 2 . .. , , .

/ :

• byte[]

  
  
  
  
  

• char[]

  
  
  
  
  

• string

  
  
  
  
  

• byte*

  
  
  
  
  

• char*

  
  
  
  
  

• Span<byte>

  
  
  
  
  

• Span<char>

  
  
  
  
  

All this lies inside the two classes BaseNDecoder / BaseNEncoder .

The following encoding dictionaries are supported:

• Base16 (hexadecimal / lower / upper)

  
  
  
  
  

• Base32

  
  
  
  
  

• ZBase32

  
  
  
  
  

• Base64

  
  
  
  
  

• Base64 Url-safe

  
  
  
  
  

using deniszykov.BaseN;

var bytes = Base64Convert.ToBytes("eg==");
// bytes[0] -> 122
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

A richer set offers the BaseNEncoding class which implements System.Text.Encoding .

using deniszykov.BaseN;

var count = BaseNEncoding.Base64Url.GetByteCount("eg=="); // -> 1
var bytes = BaseNEncoding.Base64Url.GetBytes("eg=="); // -> 122

var baseNEncoder = new BaseNEncoder(BaseNAlphabet.Base64Alphabet);
var input = "eg==";
var output = new byte[1024];
baseNEncoder.Convert(input, 0, 4, output, 0, 1, true, out var charsUsed, out var bytesUsed, out var completed);
// output[0] -> 122

      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

Other examples of "simple" use are here . You can use your own dictionary. There will be no complex examples, those who need it can find them in tests :)

Install-Package deniszykov.BaseN