Add check-password.ps1

Scripts/check-password.ps1

@@ -0,0 +1,52 @@
+<#
+.SYNOPSIS
+        Checks a password
+.DESCRIPTION
+        This PowerShell script checks the security status of the given password by haveibeenpwned.com
+.EXAMPLE
+        PS> ./check-password qwerty
+		⚠️ Bad password, it's already listed in 10584568 known security breaches!
+.LINK
+        https://github.com/fleschutz/PowerShell
+.NOTES
+        Author: Markus Fleschutz | License: CC0
+#>
+
+param([string]$password = "")
+
+function CalculateHashSHA1 ([string]$string) {
+    $sha1 = New-Object System.Security.Cryptography.SHA1CryptoServiceProvider
+    $encoder = New-Object System.Text.UTF8Encoding
+    $bytes = $encoder.GetBytes($string)
+    $hash = ($sha1.ComputeHash($bytes) | % { $_.ToString("X2") }) -join ''
+    return $hash
+}
+
+function Get-PasswordPwnCount { [CmdletBinding()] param([string]$pass)
+    $hash  = CalculateHashSHA1 $pass
+    try {
+        $uri = "https://api.pwnedpasswords.com/range/$($hash.Substring(0,5))"
+        $list  = -split (Invoke-RestMethod $uri -Verbose:($PSBoundParameters['Verbose'] -eq $true) -ErrorAction Stop) # split into separate strings
+        $pwn = $list | Select-String $hash.Substring(5,35) # grep
+        if ($pwn) { $count = [int] ($pwn.ToString().Split(':')[1]) } else { $count = 0 }
+        return $count
+    }
+    catch {
+        Write-Error "Error Calling HIBP API"
+        return $null
+    }
+}
+
+try {
+	if ($password -eq "") { $password = Read-Host "Enter the password" }
+	$NumBreaches = Get-PasswordPwnCount $password
+	if ($NumBreaches -eq 0) {
+		"👍 Password seems good, it's not listed in any known security breach (as of today)" 
+	} else {
+		"⚠️ Bad password, it's already listed in $NumBreaches known security breaches!"
+	}
+	exit 0 # success
+} catch {
+	"⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
+	exit 1
+}