Challenge description

What password makes the program print “you got it!”?

Flag format: RISC{password}

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Approach

Decompiling the binary gives us the following data declarations.

void *_dso_handle = &_dso_handle;
char *PASSWORD = "a472e82e048f12f622ef7cc554ec580a";
_UNKNOWN edata;
FILE *_bss_start;
FILE *stdin;
FILE *stderr;
char completed_0;

And the following main function.

int __fastcall main(int argc, const char **argv, const char **envp)
{
	char s[136];
	unsigned __int64 v5;

	v5 = __readfsqword(0x28u);
	setvbuf(_bss_start, 0, 2, 0);
	setvbuf(stderr, 0, 2, 0);
	printf("Enter password: ");
	if ( !fgets(s, 128, stdin) )
		die("no input");
	s[strcspn(s, "\n")] = 0;
	if ( !strcmp(s, PASSWORD) )
		puts("you got it!");
	else
		puts("nope");
	return 0;
}

We can see the program uses strcmp to compare our input to the password. This means PASSWORD is the password in plaintext.

So our flag is:

RISC{a472e82e048f12f622ef7cc554ec580a}