AFBase32

An implementation of Douglas Crockford's Base32 encoding in Objective-C. See http://www.crockford.com/wrmg/base32.html for more information.

Note: This library should not be mistaken for the RFC4648 data encoding specifications.

IMPORTANT NOTE: This library can only encode decimal values with 19 or less digits. This limitation is there to prevent any of the underlaying primitive data structures from overflowing.

OS Compatibility

• The actual library (AFBase32.h and AFBase32.m) should be usable on iOS 4 or later, or OS X v10.7 or later. Since NSRegularExpression (iOS, OS X) is used for encoding, iOS 4 or OS X v10.7 is required.
• The demo project requires iOS 7.1 or higher.

ARC Compatibility

AFBase32 can automatically detect whether your project is using ARC, and generate the correct code using conditional compilation. Therefore, it will work regardless of your project's ARC settings.

Dependencies

None.

Installation

To use the AFBase32 class and the corresponding AFBase32Crockford NSString category in your project, just drag the header and implementation files (AFBase32.h and AFBase32.m) into your project and import the header file into any class where you wish to use the Base32 functionality.

Usage

To encode a number, for example '1234':

NSLog(@"%@", [AFBase32 encode:@"1234"]);

which will yield:

16J

To decode a Base32 string, for example '14SC0PJ'

NSLog(@"%@", [AFBase32 decode:@"14SC0PJ"]);

which will yield:

1234567890

NSString Extensions

AFBase32 extends NSString with the AFBase32Crockford category and two utility methods.

For encoding a string representation of a decimal number to Base32:

- (NSString *)base32EncodedString;

For example:

NSLog(@"%@", [@"1234" base32EncodedString]);

will give you:

16J

For decoding a Base32 string into its original decimal value:

- (NSString *)decodeBase32String;

For example:

NSLog(@"%@", [@"14SC0PJ" decodeBase32String]);

will give you:

1234567890

Demo Project

The demo project comes with an iOS app that can be used as a rudimentary encoder/decoder. There is a UI for entering decimal numbers and encoding and decoding strings. There are also four small tests -- two encoding and two decoding -- that demonstrate the usage of the library.

Note that the demo project requires iOS 7.1 or above. The actual library should be usable on iOS 4 or later, or OS X v10.7 or later.

License

MIT License (MIT)

Copyright (c) 2015 Ashkan Farhadtouski

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
IN THE SOFTWARE.