Password requirements check-CodePudding

I'm trying to write a password requirement checker.. however regex is causing some issues, any suggestions?

regex="^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[@$!%*?&])([a-zA-Z0-9@$!%*?&]{7,16})$"

CodePudding user response：

This is the kind of thing that benefits from multiple tests:

password=$1
length=${#password}

# separate regular expressions
lower='[abcdefghijklmnopqrstuvwxyz]'
upper="${lower^^}"
digit='[0123456789]'
punct='[@$!%*?&]'

if [[ $password =~ $upper ]] &&
   [[ $password =~ $lower ]] &&
   [[ $password =~ $digit ]] &&
   [[ $password =~ $punct ]] &&
   (( 7 <= length && length <= 16 ))
then
    echo OK
else
    echo not OK
fi

It would be helpful for users to tell then which criteria are failing.

CodePudding user response：

I wouldn't use a singular regex statement, as it's pretty complicated . Why not use Linux's already built in checks in a simple if ? Some of which is regex-ish .. But it can be broken down easier, and managed.

#!/bin/bash

read password

if [[ ${#password} -ge 7 && ${#password} -le 16 && "$password" == *[A-Z]* && "$password" == *[a-z]* && "$password" == *[0-9]* ]]; then
   echo "Password match the criteria"
else
   echo "It doesn't match the criteria"

-ge - greater than or equal to in length
-le - less than or equal to in length
== *[A-Z]* contains caps
== *[a-z]* contains lowers
== *[0-9]* contains numbers
=~ ['!@#$%^&*()_ '] contains special character #must be in the list

You can continue with these "mini" checks as many as you wish to tailor the statement to your needs, without affecting a huge regex statement.

CodePudding user response：

You can use something like this:

if [[ ${#password} -ge 7 && "$password" == *[a-zA-Z0-9]* && "$password" =~ ['!@#$%^&*()_ '] && -le 16 ]]; then
    echo "Password is valid"
else
    echo "Something with password is wrong!"
fi

So, you check the string for parameters such as:

More or equal 7 symbols
Less or equal 16 symbols
Minimum 1 Upper-Case symbol
Minimum 1 Lower-Case symbol
Minimum 1 Number
Minimum 1 Special char