Solving a challenge which i encountered in a CTF, i don't remembers exactly which.
The function which determined whether the input was valid or not.
int check_val(char *input)
{
int len = strlen(input);
int i,ans;
ans = 0xdeadbeef;
for(i=0;i<len;i++)
{
ans = (int)input[i] + ans*0x8;
}
if(ans == 0xcafebabe)
{
return 1;
}
return 0;
}Output from the solver:
Len: 9 GVF@bBQH> Len: 10 T[y/9[@!@~ Len: 11 R_Dg}H`RR@> Len: 12 BICbxz$@T@H~ Len: 13 BBSXBA,TBBR9v Len: 14 BBBSQyH9(\rN`> Len: 15 BPBBRY~"*'*BPS& Len: 16 BBBBBJ]WR_xd4D2. Len: 17 BBDBBBPS*B'@"H!@~ Len: 18 BDBHBBBQGByg|>cJ@> Len: 19 BBBBBBBDSXC6H2RD@S&