NSString+SO.m

//
//  NSString+SO.m
//
//  Created by Ezo Saleh on 04/12/2011.
//

#import "NSString+SO.h"

@implementation NSString (SO)

//Source http://www.cocoadev.com/index.pl?BaseSixtyFour

+ (NSString *)base64forData:(NSData *)data
{
    static const char encodingTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    
    if ([data length] == 0)
        return @"";
    
    char *characters = malloc((([data length] + 2) / 3) * 4);
    if (characters == NULL)
        return nil;
    NSUInteger length = 0;
    
    NSUInteger i = 0;
    while (i < [data length])
    {
        char buffer[3] = {0,0,0};
        short bufferLength = 0;
        while (bufferLength < 3 && i < [data length])
            buffer[bufferLength++] = ((char *)[data bytes])[i++];
        
        //  Encode the bytes in the buffer to four characters, including padding "=" characters if necessary.
        characters[length++] = encodingTable[(buffer[0] & 0xFC) >> 2];
        characters[length++] = encodingTable[((buffer[0] & 0x03) << 4) | ((buffer[1] & 0xF0) >> 4)];
        if (bufferLength > 1)
            characters[length++] = encodingTable[((buffer[1] & 0x0F) << 2) | ((buffer[2] & 0xC0) >> 6)];
        else characters[length++] = '=';
        if (bufferLength > 2)
            characters[length++] = encodingTable[buffer[2] & 0x3F];
        else characters[length++] = '=';        
    }
    
    return [[NSString alloc] initWithBytesNoCopy:characters length:length encoding:NSASCIIStringEncoding freeWhenDone:YES];
}

- (BOOL)isOnlyFromCharacterSet:(NSCharacterSet *)aCharacterSet {
	NSString *s = [[self lowercaseString] copy];
	
	unichar c;
	for(NSUInteger i = 0; i < [s length]; i++) {
		[s getCharacters:&c range:NSMakeRange(i, 1)];
		if([aCharacterSet characterIsMember:c] == NO) {
			return NO;
		}
	}
	
	return YES;
}

- (BOOL)isHexadecimal {
	NSCharacterSet *hexadecimalCharacterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789abcdef"];
	return [self isOnlyFromCharacterSet:hexadecimalCharacterSet];
}

-(NSString *)MD5{
    // Create pointer to the string as UTF8
    const char *ptr = [self UTF8String];
    
    // Create byte array of unsigned chars
    unsigned char md5Buffer[CC_MD5_DIGEST_LENGTH];
    
    // Create 16 byte MD5 hash value, store in buffer
    CC_MD5(ptr, strlen(ptr), md5Buffer);
    
    // Convert MD5 value in the buffer to NSString of hex values
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    
    for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) 
        [output appendFormat:@"%02x",md5Buffer[i]];
    
    return output;
}

-(NSString *) SHA1{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    uint8_t digest[CC_SHA1_DIGEST_LENGTH];
    
    CC_SHA1(data.bytes, data.length, digest);
    
    NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
    
    for(int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++)
        [output appendFormat:@"%02x", digest[i]];
    
    return output;
    
}

@end