md5加密32位

MD5加密算法，实现类别如下：

#import <CommonCrypto/CommonDigest.h>

@interface NSString (md5)

-(NSString *) md5HexDigest;

@end

#import "NSString+MD5HexDigest.h"

@implementation NSString (md5)

-(NSString *) md5HexDigest

{

const char *original_str = [self UTF8String];

unsigned char result[CC_MD5_DIGEST_LENGTH];

CC_MD5(original_str, strlen(original_str), result);

NSMutableString *hash = [NSMutableString string];

for (int i = 0; i < 16; i++)

[hash appendFormat:@"%02X", result[i]];

return [hash lowercaseString];

}

@end