//导入头文件#import 
     
      @implementation WXUtil+(NSString *)md5:(NSString *)str{    const char *CStr = str.UTF8String;    /**     *  @param data#> 要加密的C语言字符串     *  @param len#>  C语言字符串的长度     *  @param md#>   生成的16个16进制字符的数组的首地址     */    //声明一个字符数组  可存放16个字符    unsigned char result[CC_MD5_DIGEST_LENGTH];    CC_MD5(CStr, (CC_LONG)strlen(CStr), result);    //遍历该C语言数组 将其中的16个字符串拼接起来,形成OC字符串    NSMutableString *string = [NSMutableString string];    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {        [string appendFormat:@"%02X",result[i]];    }    return string;}+(NSString *)sha1:(NSString *)str{    const char *cstr = [str cStringUsingEncoding:NSUTF8StringEncoding];    NSData *data = [NSData dataWithBytes:cstr length:str.length];    uint8_t digest[CC_SHA1_DIGEST_LENGTH];    CC_SHA1(data.bytes, (unsigned int)data.length, digest);    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH*2];    for (int i = 0; i< CC_SHA1_DIGEST_LENGTH; i++) {        [output appendFormat:@"%02x",digest[i]];    }    return output;}