iOS MD5加密算法

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

    @interface MD5 : NSObject  


    /** 
    *   MD5加密，传入需要加密的字符串，不可逆 
    * 
    *  @param str 需要加密的字符串 
    * 
    *  @return 加密后字符串 
    */  
    + (NSString *)md5:(NSString *)str;  

    @end  

    #import "MD5.h"  

    @implementation MD5  

    + (NSString *)md5:(NSString *)str  
    {  
        const charchar *cStr = [str UTF8String];  
        unsigned char result[16];  
        CC_MD5(cStr, strlen(cStr), result); // This is the md5 call  
        NSString * string =  [NSString stringWithFormat:  
                @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",  
                result[0], result[1], result[2], result[3],  
                result[4], result[5], result[6], result[7],  
                result[8], result[9], result[10], result[11],  
                result[12], result[13], result[14], result[15]  
                ];  
        return [string substringWithRange:NSMakeRange(8, 16)];  
    }  



    @end  

    NSString *str=@"准备加密";  
    NSString *str1=[MD5 md5:str];  
    NSLog(@"str=%@,str1=%@",str,str1);