MD5 hash of NSData

NSData_MD5.h

#import <Foundation/Foundation.h>

@interface NSData (NSData_MD5)
- (NSString *)md5;
@end

NSData_MD5.m

#import "NSData_MD5.h"
#import <CommonCrypto/CommonDigest.h>

@implementation NSData (NSData_MD5)
- (NSString *)md5 {
  unsigned char hash[CC_MD5_DIGEST_LENGTH];
  CC_MD5([self bytes], [self length], hash);
  char hashstr[CC_MD5_DIGEST_LENGTH*2];
  for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
    snprintf(&hashstr[i*2], 2, "%.2x", hash[i]);
  }
  return [[[NSString alloc] initWithBytes:hashstr length:CC_MD5_DIGEST_LENGTH*2 encoding:NSASCIIStringEncoding] autorelease];
}