md5.m

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

@interface NSString (MD5)

- (NSString *) MD5String;

@end

@implementation NSString (MD5)

- (NSString *) MD5String {
   const char *cStr = [self UTF8String];
   unsigned char digest[CC_MD5_DIGEST_LENGTH];
   CC_MD5( cStr, strlen(cStr), digest );

   char md5string[CC_MD5_DIGEST_LENGTH*2];

   int i;
   for (i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
      sprintf(md5string+i*2, "%02X", digest[i]);
   }

   return [NSString stringWithCString:md5string length:CC_MD5_DIGEST_LENGTH*2];
}

@end