Checking SSL certificate values with Powershell

For anyone that needs to check SSL certificates in a simple way from Powershell, I created something for this purpose a while back. It works for most SSL connections using .NET code and will throw exceptions if the name on the cert you provide is not valid, or the cert is expired.

Check-sslcert.ps1 (Updated Jan 15, 2013)

#Requires -version 2.0
 
param(
 [parameter(mandatory=$true,helpmessage="IP address or hostname to resolve remote system")][string]$ipaddr,
 [parameter(mandatory=$true,helpmessage="TCP port number that SSL application is listening on")][int]$port,
 [parameter(helpmessage="Hostname on certificate")][string]$myhostname=$ipaddr,
 [parameter(helpmessage="Verbose")][alias('fulldetail')][switch]$V
 
)


function stripcomma([string]$tempstring) {
 write-debug "In Function StripComma $($tempstring)"
 return $tempstring.replace(',',';') 
 
}

function convertoid([string]$oid) {
 write-debug "In function ConvertToOID: $($oid)"
 #strip off oid component common to all crypto types
 $oidstr = $oid.replace("1.2.840.113549.1.","")
 
 #pull out first number
 $firstval = $oidstr.substring(0,$oidstr.indexof('.'))
 
 #pull out second number for more detail
 $sub = $oidstr.substring(2)
 if ($sub.indexof('.') -gt 0) {
  $sub = $sub.substring(0,$sub.indexof('.')) 
 }
 
 if ($firstval -eq "1") {
  $format = "PKCS-1"
  switch ($sub) {
   "1" { return ($format + " RSA Encryption") }
   "2" { return ($format + " MD2 with RSA") }
   "3" { return ($format + " rsadsi md4 with RSA")}
   "4" { return ($format + " MD5 with RSA") }
   "5" { return ($format + " SHA-1 with RSA") }
   "6" { return ($format + " rsaOAEPEncryptionSet")}
   "11" { return ($format + " sha256 with RSA") }
  }
 } elseif ($firstval -eq "5") {
  $format = "RSA PKCS5"
  switch ($sub) {
   "1" { return ($format + " rsadsi pbe with MD2 DES-CBC")}
   "3" { return ($format + " rsadsi pbe with MD5 DES-CBC")}
   "4" { return ($format + " pbe with MD2 and RC2_CBC")}
   "6" { return ($format + " pbe with MD5 and RC2_CBC")}
   "9" { return ($format + " pbe with MD5 and XOR")}
   "10" { return ($format + " pbe with SHA1 and DES-CBC")}
   "11" { return ($format + " pbe with SHA1 and RC2_CBC")}
   "12" { return ($format + " id-PBKDF2 key derivation function")}
   "13" { return ($format + " id-PBES2  PBES2 encryption")}
   "14" { return ($format + " id-PBMAC1 message auth scheme")}
   
  }
 } elseif ($firstval -eq "7" ) {
  $format = "PKCS-7"
  switch ($sub) {
   "1" { return ($format + " data")}
   "2" { return ($format + " signed data")}
   "3" { return ($format + " enveloped data")}
   "4" { return ($format + " signed and enveloped data")}
   "5" { return ($format + " digested data")}
   "6" { return ($format + " encrypted data")}
  }
 } elseif ($firstval -eq "12") {
  return ("PKCS-12")
 } elseif ($firstval -eq "15") {
  return ("PKCS-15") 
 } else {
  return $oid 
 }
   
 
}

######
#MAIN#
######

#open TCP connection
try {
 $conn = new-object system.net.sockets.tcpclient($ipaddr,$port) 
 
 try {
  #create ssl stream on existing tcp connection
  $stream = new-object system.net.security.sslstream($conn.getstream())
  #send hostname on cert to try SSL negotiation
  $stream.authenticateasclient($myhostname) 
  
  $cert = $stream.get_remotecertificate()
  $cert2 = New-Object system.security.cryptography.x509certificates.x509certificate2($cert)    #can get much more information with this class    

  $validto = [datetime]::Parse($cert.getexpirationdatestring())
  $validfrom = [datetime]::Parse($cert.geteffectivedatestring())
  
  if ($V) {
   new-object psobject -property @{ 
    Connection = "Success"
    Machine = $ipaddr
    CertFormat = ($cert.getformat())
    CertExpiration = $validto
    CertIssueDate = $validfrom
    CertIssuer = ($cert.get_issuer())
    SerialNumber = ($cert.getserialnumberstring())
    CertSubject = (stripcomma $cert.get_subject())
    CertType =  (convertoid $cert.getkeyalgorithm())
   }
  } else {
   #non verbose
   New-Object psobject -Property @{
    Connection = "Success"
    Machine = $ipaddr
    CertExpiration = $validto
   }
  }

 } catch {
  #if SSL connection failed, cert may be invalid or name on cert didn't match, fails either way
  throw $_
 } finally {
  Write-Debug "In finally: closing connection"
  $conn.close()
 }
} catch {
 Write-Verbose "Error occurred connecting to $($ipaddr)"
 New-Object PSObject -Property @{
  Machine = $ipaddr
  Connection = "Failure"
  Status = $_.exception.innerexception.message
 }
 
}