NSData+Base64

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NSData+Base64.h

#import <Foundation/Foundation.h>

@interface NSData (Base64)

+ (NSData *)dataWithBase64EncodedString:(NSString *)string;

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth;

- (NSString *)base64EncodedString;

@end

NSData+Base64.m

#import "NSData+Base64.h"

@implementation NSData (Base64)

+ (NSData *)dataWithBase64EncodedString:(NSString *)string

{

const char lookup[] =

{

99, 99, 99, 99, 99,99, 99, 99, 99, 99,99, 99, 99, 99, 99,99,

99, 99, 99, 99, 99,99, 99, 99, 99, 99,99, 62, 99, 99, 99,63,

52, 53, 54, 55, 56,57, 58, 59, 60, 61,99, 99, 99, 99, 99,99,

99, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14,

15, 16, 17, 18, 19,20, 21, 22, 23, 24,25, 99, 99, 99, 99,99,

99, 26, 27, 28, 29,30, 31, 32, 33, 34,35, 36, 37, 38, 39,40,

41, 42, 43, 44, 45,46, 47, 48, 49, 50,51, 99, 99, 99, 99,99

};

NSData *inputData = [stringdataUsingEncoding:NSASCIIStringEncodingallowLossyConversion:YES];

long long inputLength = [inputDatalength];

const unsignedchar *inputBytes = [inputData bytes];

long long maxOutputLength = (inputLength /4 + 1) * 3;

NSMutableData *outputData = [NSMutableDatadataWithLength:maxOutputLength];

unsigned char *outputBytes = (unsignedchar *)[outputData mutableBytes];

int accumulator = 0;

long long outputLength =0;

unsigned char accumulated[] = {0,0, 0, 0};

for (long long i = 0; i < inputLength; i++)

{

unsigned char decoded = lookup[inputBytes[i] &0x7F];

if (decoded != 99)

{

accumulated[accumulator] = decoded;

if (accumulator == 3)

{

outputBytes[outputLength++] = (accumulated[0] <<2) | (accumulated[1] >>4);

outputBytes[outputLength++] = (accumulated[1] <<4) | (accumulated[2] >>2);

outputBytes[outputLength++] = (accumulated[2] <<6) | accumulated[3];

}

accumulator = (accumulator +1) % 4;

}

//handle left-over data

if (accumulator > 0) outputBytes[outputLength] = (accumulated[0] <<2) | (accumulated[1] >>4);

if (accumulator > 1) outputBytes[++outputLength] = (accumulated[1] <<4) | (accumulated[2] >>2);

if (accumulator > 2) outputLength++;

//truncate data to match actual output length

outputData.length = outputLength;

return outputLength? outputData: nil;

}

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth

{

//ensure wrapWidth is a multiple of 4

wrapWidth = (wrapWidth /4) * 4;

constchar lookup[] ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

long long inputLength = [selflength];

const unsignedchar *inputBytes = [selfbytes];

long long maxOutputLength = (inputLength /3 + 1) * 4;

maxOutputLength += wrapWidth? (maxOutputLength / wrapWidth) *2: 0;

unsigned char *outputBytes = (unsignedchar *)malloc(maxOutputLength);

long long i;

long long outputLength =0;

for (i = 0; i < inputLength -2; i += 3)

{

outputBytes[outputLength++] = lookup[(inputBytes[i] &0xFC) >> 2];

outputBytes[outputLength++] = lookup[((inputBytes[i] &0x03) << 4) | ((inputBytes[i +1] & 0xF0) >>4)];

outputBytes[outputLength++] = lookup[((inputBytes[i +1] & 0x0F) <<2) | ((inputBytes[i + 2] & 0xC0) >> 6)];

outputBytes[outputLength++] = lookup[inputBytes[i +2] & 0x3F];

//add line break

if (wrapWidth && (outputLength + 2) % (wrapWidth + 2) == 0)

{

outputBytes[outputLength++] ='\r';

outputBytes[outputLength++] ='\n';

}

//handle left-over data

if (i == inputLength - 2)

{

// = terminator

outputBytes[outputLength++] = lookup[(inputBytes[i] &0xFC) >> 2];

outputBytes[outputLength++] = lookup[((inputBytes[i] &0x03) << 4) | ((inputBytes[i +1] & 0xF0) >>4)];

outputBytes[outputLength++] = lookup[(inputBytes[i +1] & 0x0F) <<2];

outputBytes[outputLength++] = '=';

}

else if (i == inputLength -1)

{

// == terminator

outputBytes[outputLength++] = lookup[(inputBytes[i] &0xFC) >> 2];

outputBytes[outputLength++] = lookup[(inputBytes[i] &0x03) << 4];

outputBytes[outputLength++] ='=';

}

//truncate data to match actual output length

outputBytes =realloc(outputBytes, outputLength);

NSString *result = [[NSStringalloc] initWithBytesNoCopy:outputByteslength:outputLengthencoding:NSASCIIStringEncodingfreeWhenDone:YES];

#if !__has_feature(objc_arc)

[resultautorelease];

#endif

return (outputLength >= 4)? result: nil;

}

- (NSString *)base64EncodedString

{

return [selfbase64EncodedStringWithWrapWidth:0];

}

@end

NSString+Base64.h

#import <Foundation/Foundation.h>

@interface NSString (Base64)

+ (NSString *)stringWithBase64EncodedString:(NSString *)string;

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth;

- (NSString *)base64EncodedString;

- (NSString *)base64DecodedString;

- (NSData *)base64DecodedData;

@end

NSstring+Base64.m

#import "NSString+Base64.h"

#import "NSData+Base64.h"

@implementation NSString (Base64)

+ (NSString *)stringWithBase64EncodedString:(NSString *)string

{

NSData *data = [NSDatadataWithBase64EncodedString:string];

if (data)

{

NSString *result = [[selfalloc] initWithData:dataencoding:NSUTF8StringEncoding];

#if !__has_feature(objc_arc)

[resultautorelease];

#endif

return result;

}

return nil;

}

- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth

{

NSData *data = [selfdataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];

return [database64EncodedStringWithWrapWidth:wrapWidth];

}

- (NSString *)base64EncodedString

{

NSData *data = [selfdataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];

return [database64EncodedString];

}

- (NSString *)base64DecodedString

{

return [NSStringstringWithBase64EncodedString:self];

}

- (NSData *)base64DecodedData

{

return [NSDatadataWithBase64EncodedString:self];

}

@end

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