cog/Utils/NSData+MD5.m

//
//  NSData+MD5.m
//  Cog
//
//  Created by Christopher Snowhill on 10/9/13.
//
//

#import <CommonCrypto/CommonDigest.h>

#import "NSData+MD5.h"

@implementation NSData (MD5)

- (NSString *)MD5 {
	// Create pointer to the string as UTF8
	const void *ptr = [self bytes];
	NSUInteger len = [self length];

	// 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, (int)len, 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;
}

@end