Password Complexity Validation with PowerShell

Sometimes you need to verify if a password meets some minimal requirements such as length, upper- and lowercase characters and special chars.

This simple script validates if a string / password matches at least these minimum requirements:

• At least one uppercase character
• At least one lowercase character
• At least one digit
• At least one special char
• At least 10 characters in length

1
2
3
4
5
6
7
8
9
10
11
12
13

$password = 'mySecure!P@ssword$'
 
$counter = 0
@('[A-Z]', '[a-z]', '\d', '[\41-\57\100\133-\140]', '.{10,}') | foreach {
    if(($str -creplace $_, '') -ne $str) { $counter++ }
}
 
if($counter -ge 5){
    Write-Host "Strong password"
}
else {
    Write-Host "Weak password"
}