Base85

⛔️ Deprecated

Please use the Bases Package.

Base85 is a Swift library to convert data from Base-85 and vice versa. The API was designed to easily replace the Foundation's built-in Base-64 encoding API.

Installation

You can install this package through Swift Package Manager. Either add this to your Package.swift:

dependencies: [
    .package(url: "https://github.com/pambrozy/Base85", .upToNextMajor(from: "1.0.0")),
    ...
],

Or, by using Xcode:

1. Select File → Swift Packages → Add Package Dependency...
2. Enter package URL: https://github.com/pambrozy/Base85

Usage

Foundation

To encode data use the following functions:

let encodedData = data.base85EncodedData()

let encodedString = data.base85EncodedString()

You can also specify encoding options and character set (the default is RFC 1924, see all):

data.base85EncodedData(options: .lineLength64Characters,
                       encoding: .z85)

data.base85EncodedString(options: [.endLineWithCarriageReturn,
                                   .lineLength76Characters],
                         encoding: .adobeAscii85)

In order to decode data:

let fromString = Data(base85Encoded: "JQEepgAAAABM9s8PUbctjl7/Wxk=")

let fromData = Data(base85Encoded: encodedData,
                    options: .ignoreUnknownCharacters,
                    encoding: .rfc1924)

You can also use this library to encode and decode raw data from and into JSON:

let encoder = JSONEncoder()
encoder.dataEncodingStrategy = .base85

let decoder = JSONDecoder()
decoder.dataDecodingStrategy = .base85(encoding: .btoa)

Standalone

To encode data:

// The type of `data` is [UInt8]
let encoded = Base85.encode(data, encoding: .rfc1924)

To decode data:

// The type of `data` is [UInt8]
let decoded = Base85.decode(data, encoding: .rfc1924)

Character sets

This package comes with some character sets build in. They are referred in code as Base85.Encoding. The default encoding is RFC 1924.

Built in character sets:

Encoding	ascii	btoa	Ascii85 (Adobe)	RFC 1924	Z85
Characters	! - u	! - u	! - u	0 - ~	0 - #
Beginning of string	-	-	<~	-	-
End of string	-	x	~>	-	-
Four zeros	-	z	z	-	-
Four spaces	-	y	-	-

Custom character set

You can customize each character set by using this static method:

let customizedBtoa = Base85.Encoding.customized(baseEncoding: .btoa,
                                                startDelimeter: nil,
                                                endDelimeter: "x",
                                                representFourZerosAs: "z",
                                                representFourSpacesAs: nil)

You can also create a fully custom character set, by using the following method:

Base85.Encoding.custom(characters: [Character],
                       startDelimeter: String?,
                       endDelimeter: String?,
                       representFourZerosAs zeros: Character?,
                       representFourSpacesAs spaces: Character?)

• The smallest character value cannot be smaller than 33 (ASCII "!").
• The number of characters should be 85.

Todo

• Test Foundation extensions
• Test customized and custom encoding
• Make Base85.encode and Base85.decode throw an error instead of returning nil in case of failure

License

This package is released under The MIT License. See LICENSE for details.