UrlBase64

UrlBase64 is a package for all versions of the .NET Framework and .NET Core, which supports the creation of url-safe base64 encoding. UrlBase64 provides symmetric routines to both encode and later decode data in a fashion that makes it safe for use on the general web and as input to ASP.NET web applications (under IIS or similar).

Installation

UrlBase64 is available via nuget and the Visual Studio package manager. To install, simply run the following in the package manager console:

Install-Package UrlBase64

Or search for UrlBase64 in the Visual Studio package manager.

Usage

All functions are contained in the static UrlBase64 class, found in the NeoSmart.Utils namespace.

using NeoSmart.Utils;

void UsageSample()
{
	var foo = Encoding.UTF8.GetBytes("foo");
	var encoded = UrlBase64.Encode(foo);
	var decoded = UrlBase64.Decode(encoded);

	var bar = Encoding.UTF8.GetString(decoded);

	Assert.AreEqual("foo", bar);
}

Padding Options (Encoding)

UrlBase64 supports two different padding modes (internally: PaddingPolicy) for generating base64 content:

public enum PaddingPolicy
{
	Discard,
	Preserve,
}

The PaddingPolicy option controls the behavior of UrlBase64 when encoding content that does not fall on a 4-character (output) boundary. Per RFC 4648, base64 specifies that an "optional depending on the circumstances" trailing = sign is used to pad the output to be a multiple of 4 characters long. UrlBase64 supports both padded and unpadded output via an optional PaddingPolicy parameter to UrlBase64.Encode controlling this behavior. The default behavior at this time is to omit the trailing padding given that it a) can (and usually is) be inferred automatically when dropped from the encoded output, and b) utilizes a symbol that requires encoding when used in URLs.

var bytes = Encoding.UTF8.GetBytes("Mary had a little lamb");
Console.WriteLine(bytes, UrlBase64.Encode(bytes, PaddingPolicy.Discard));
Console.WriteLine(bytes, UrlBase64.Encode(bytes, PaddingPolicy.Preserve));

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License and Copyright

UrlBase64 is developed by Mahmoud Al-Qudsi of NeoSmart Technologies. UrlBase64 is released under the terms of the MIT Public License. Copyright NeoSmart Technologies 2017-2018.