Private/Test-ValidKey.ps1
|
function Test-ValidKey { [CmdletBinding()] param( [Parameter(Mandatory,Position=0)] [Security.Cryptography.AsymmetricAlgorithm]$Key, [switch]$ThrowOnFail ) # Key must be RSA or ECDsa type if ($Key -isnot [Security.Cryptography.RSA] -and $Key -isnot [Security.Cryptography.ECDsa]) { if ($ThrowOnFail) { throw [Management.Automation.ValidationMetadataException] "Invalid key type." } return $false } # For RSA keys, Windows supports a huge range of key sizes. But LE's current Boulder server only supports # between 2048-4096 keys. So we'll limit to that until someone complains. # https://msdn.microsoft.com/en-us/library/system.security.cryptography.rsacryptoserviceprovider.keysize(v=vs.110).aspx if ($Key -is [Security.Cryptography.RSA] -and ($Key.KeySize -lt 2048 -or $Key.KeySize -gt 4096 -or ($Key.KeySize % 128) -ne 0)) { if ($ThrowOnFail) { throw [Management.Automation.ValidationMetadataException] "RSA key size out of range. Must be 2048-4096 (divisible by 128)." } return $false } # For EC keys, LE's current Boulder server only supports P-256 and P-384, but may support P-521 in the future. # In all testing so far, the KeySize matches the "P-xxxx" curve name. So we'll just use that to test # until someone finds a contrary example. The alternative is checking $Key.Key.Algorithm, but that's not currently # working against PowerShell Core. if ($Key -is [Security.Cryptography.ECDsa] -and $Key.KeySize -notin 256,384) { if ($ThrowOnFail) { throw [Management.Automation.ValidationMetadataException] "EC curve out of range. Must be P-256 or P-384." } return $false } return $true } |