Password from Key and Hash

Question

I am trying to get the key this key for an assignment I was provided with the key and hash. In PowerShell how do I convert this to plain text. Any guidance is appreciated.

I have tried these

PS C:\test> $PlainPassword = Get-Content C:\test\secure-hash.txt

PS C:\test> $SecurePassword = ConvertTo-SecureString $PlainPassword -AsPlainText -Force

PS C:\test> 

I've tried ConvertFrom-SecureString input hash with no success

Answer 1

The process of exporting and importing a Password using the -Key parameter goes like this:

1. You need to generate a Key, for that you can use the RandomNumberGenerator Class. Note: Valid key lengths are 16, 24 and 32 bytes.

$key = [byte[]]::new(32)
$ran = [System.Security.Cryptography.RandomNumberGenerator]::Create()
$ran.GetBytes($key)

# Export the new key to a file:
Export-Clixml -InputObject $key -Path path\to\myKey.key

2. Export your password using this key.

# Import the key (it should be obtained from a Vault preferably)
$key = Import-CliXml path\to\myKey.key

$myPassWord = 'myPassword'
ConvertTo-SecureString $myPassWord -AsPlainText -Force |
    ConvertFrom-SecureString -Key $key |
    Set-Content path\to\myPassword.txt

3. Lastly you can import it whenever you want using the same key.

If you're using PowerShell Core:

# Get the encrypted password
$encryptedPassword = Get-Content path\to\myPassword.txt -Raw
# Import the key (it should be obtained from a Vault preferably)
$key = Import-CliXml path\to\myKey.key

ConvertTo-SecureString $encryptedPassword -Key $key |
    ConvertFrom-SecureString -AsPlainText
# -> Outputs: `myPassword`

If you're using Windows PowerShell:

# Get the encrypted password
$encryptedPassword = Get-Content path\to\myPassword.txt -Raw
# Import the key (it should be obtained from a Vault preferably)
$key = Import-CliXml path\to\myKey.key

$secureString = ConvertTo-SecureString $encryptedPassword -Key $key
[System.Net.NetworkCredential]::new('', $secureString).Password
# -> Outputs: `myPassword`