攻防世界 reverse open-source

题目名字叫做开源，然而二者之间并没有什么关系…
一个很简答的C程序题，让你跳过所有的限制条件即可输出key(flag)。
open-source如下：

#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[]) {
    if (argc != 4) {
    	printf("what?\n");
    	exit(1);
    }

    unsigned int first = atoi(argv[1]);
    if (first != 0xcafe) {
    	printf("you are wrong, sorry.\n");
    	exit(2);
    }

    unsigned int second = atoi(argv[2]);
    if (second % 5 == 3 || second % 17 != 8) {
    	printf("ha, you won't get it!\n");
    	exit(3);//25
    }

    if (strcmp("h4cky0u", argv[3])) {
    	printf("so close, dude!\n");
    	exit(4);
    }

    printf("Brr wrrr grr\n");

    unsigned int hash = first * 31337 + (second % 17) * 11 + strlen(argv[3]) - 1615810207;
//first=0xcafe,(second%17)=8,argv[3]="h4cky0u"
    printf("Get your key: ");
    printf("%x\n", hash);
    return 0;
}

在原程序上进行一定的修改，得到：

int main()
{
	unsigned int hash = 0xcafe * 31337 + 8 * 11 + 7 - 1615810207;

    printf("Get your key: ");
    printf("%x\n", hash);
    return 0;
}

flag：c0ffee