NSString+Base64 (iOS 7+)

Example.md

Encoding Strings

NSString *aString = @"Hello, iOS 7!" 
NSString *encodedString = [NSString encodeBase64String:aString]
NSLog(@"Encoded String %@", encodedString) // returns 'SGVsbG8sIGlPUyA3IQ=='

Decoding Strings

NSString *aString = @"SGVsbG8sIGlPUyA3IQ==" 
NSString *decodedString = [NSString decodeBase64String:aString]
NSLog(@"Decoded String %@", decodedString) // returns 'Hello, iOS 7!'

NSString+Base64.h

#import <Foundation/Foundation.h>

@interface NSString (Base64)

+ (instancetype)encodeBase64String:(NSString *)stringToEncode;
+ (instancetype)decodeBase64String:(NSString *)stringToDeccode;

@end

NSString+Base64.m

#import "NSString+ASBase64.h"

@implementation NSString (Base64)

+ (instancetype)encodeBase64String:(NSString *)stringToEncode
{
    NSData *dataToEncode = [stringToEncode dataUsingEncoding:NSUTF8StringEncoding];
    NSData *encodedData = [dataToEncode base64EncodedDataWithOptions:0];
    NSString *encodedString = [[NSString alloc] initWithData:encodedData encoding:NSUTF8StringEncoding];
    
    return encodedString;
}

+ (instancetype)decodeBase64String:(NSString *)stringToDeccode
{
    NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:stringToDeccode options:0];
    NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding];
    
    return decodedString;
}

@end