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| #import "Base64.h"
#import <Availability.h>
#if !__has_feature(objc_arc)
#error This library requires automatic reference counting
#endif
@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, 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 = [string dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
long long inputLength = [inputData length];
const unsigned char *inputBytes = [inputData bytes];
long long maxOutputLength = (inputLength / 4 + 1) * 3;
NSMutableData *outputData = [NSMutableData dataWithLength:maxOutputLength];
unsigned char *outputBytes = (unsigned char *)[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;
const char lookup[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
long long inputLength = [self length];
const unsigned char *inputBytes = [self bytes];
long long maxOutputLength = (inputLength / 3 + 1) * 4;
maxOutputLength += wrapWidth? (maxOutputLength / wrapWidth) * 2: 0;
unsigned char *outputBytes = (unsigned char *)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++] = '=';
outputBytes[outputLength++] = '=';
}
if (outputLength >= 4)
{
//truncate data to match actual output length
outputBytes = realloc(outputBytes, outputLength);
return [[NSString alloc] initWithBytesNoCopy:outputBytes
length:outputLength
encoding:NSASCIIStringEncoding
freeWhenDone:YES];
}
else if (outputBytes)
{
free(outputBytes);
}
return nil;
}
- (NSString *)base64EncodedString
{
return [self base64EncodedStringWithWrapWidth:0];
}
@end
@implementation NSString (Base64)
+ (NSString *)stringWithBase64EncodedString:(NSString *)string
{
NSData *data = [NSData dataWithBase64EncodedString:string];
if (data)
{
return [[self alloc] initWithData:data encoding:NSUTF8StringEncoding];
}
return nil;
}
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
return [data base64EncodedStringWithWrapWidth:wrapWidth];
}
- (NSString *)base64EncodedString
{
NSData *data = [self dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:YES];
return [data base64EncodedString];
}
- (NSString *)base64DecodedString
{
return [NSString stringWithBase64EncodedString:self];
}
- (NSData *)base64DecodedData
{
return [NSData dataWithBase64EncodedString:self];
}
@end |
