iOS 對字符串進行MD5處理

1、導入頭文件 

#import <CommonCrypto/CommonDigest.h>

+ ( NSString *)md5String:( NSString *)str {
    
    const char *myPasswd = [str UTF8String ];
    
    unsigned char mdc[ 16 ];
    
    CC_MD5 (myPasswd, ( CC_LONG ) strlen (myPasswd), mdc);
    
    NSMutableString *md5String = [ NSMutableString string ];
    
    for ( int i = 0 ; i< 16 ; i++) {
        
        [md5String appendFormat : @"%02x" ,mdc[i]];
        
    }
    
    return md5String;
}