[SOLVED] For loop in BASH to get username and password tuple

For loop in BASH to get username and password tuple

I am writing a simple script with Bash 4.4.23, to perform a demonstrative dictionary attack towards various web servers which use default passwords.

The arrays containing usernames and passwords are declared above the "for" cycles, which are as follows:

for i in $usernames
do for j in $passwords
    do printf '%s ' "${usernames[*]}:${passwords[*]}"
done
done

The code should return something like:

root:root root:admin admin:admin admin:root

But instead it is returning

root admin:root admin

Which are the values declared within the arrays (usernames and passwords).

How can I achieve what I'm trying to do? The tuples will then have to be passed to curl in order to perform the dictionary attack.

Solution

You have the arrays and the elements you loop over mixed up. You loop over the array. You use the loop variable inside the loop.

for i in "${usernames[@]}"
  do for j in "${passwords[@]}"
    do printf '%s:%s ' "$i" "$j"
  done
done

The symptom you see is because $usernames alone refers to the first element of the array, and similarly for the other array variable.