In my last post I showed you a function to generate secure and complex passwords. This time I have written a small function you can use to test password strength similar to the strength bar you sometimes see in password fields on websites.
The output is a simple string telling you the strength of the password.
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function Test-PasswordStrength { | |
<# | |
.SYNOPSIS | |
Test password strength. | |
.DESCRIPTION | |
This functions lets input a password to test it strength. | |
.EXAMPLE | |
Test-PasswordStrength 'MyCoolPassword' | |
.NOTES | |
Based on code example from https://social.msdn.microsoft.com/Forums/vstudio/en-US/5e3f27d2-49af-410a-85a2-3c47e3f77fb1/how-to-check-for-password-strength?forum=csharpgeneral | |
Author: Øyvind Kallstad | |
Date: 24.09.2015 | |
Version: 1.0 | |
.OUTPUTS | |
System.String | |
.LINK | |
https://communary.wordpress.com/ | |
#> | |
[CmdletBinding()] | |
param ( | |
# The password to test | |
[Parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $true)] | |
[ValidateNotNullOrEmpty()] | |
[string] $Password | |
) | |
$score = 0 | |
if ($Password.Length -lt 5) { | |
Write-Verbose 'Password length is less than 5 characters.' | |
Write-Output 'Very Weak' | |
break | |
} | |
if ($Password.Length -ge 8) { | |
Write-Verbose 'Password length is equal to or greater than 8 characters. Added 1 to password score.' | |
$score++ | |
} | |
if ($Password.Length -ge 12) { | |
Write-Verbose 'Password length is equal to or greater than 12 characters. Added 1 to password score.' | |
$score++ | |
} | |
if ([regex]::IsMatch($Password, '\d+')) { | |
Write-Verbose 'Password contains numbers. Added 1 to password score.' | |
$score++ | |
} | |
if ([regex]::IsMatch($Password, '[a-z]+')) { | |
Write-Verbose 'Password lowercase letters. Added 1 to password score.' | |
$score++ | |
} | |
if ([regex]::IsMatch($Password, '[A-Z]+')) { | |
Write-Verbose 'Password uppercase letters. Added 1 to password score.' | |
$score++ | |
} | |
if ([regex]::IsMatch($Password, '[!@#$%^&*?_~-£(){},]+')) { | |
Write-Verbose 'Password symbols. Added 1 to password score.' | |
$score++ | |
} | |
switch ($score) { | |
1 { $passwordScore = 'Very Weak' } | |
2 { $passwordScore = 'Weak' } | |
3 { $passwordScore = 'Medium' } | |
4 { $passwordScore = 'Strong' } | |
5 { $passwordScore = 'Strong' } | |
6 { $passwordScore = 'Very Strong' } | |
} | |
Write-Output $passwordScore | |
} |