AutoIt

Get a Certificate's Key Size

See more Certificates Examples

Demonstrates how to get the RSA key size of a certificate (for example, 1024-bit, 2048-bit, etc.) AutoIt

Local $bSuccess = False

; For this example, I have a certificate in raw base64 format (not PEM),
; that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
$oSbCertBase64 = ObjCreate("Chilkat.StringBuilder")
$bSuccess = $oSbCertBase64.LoadFile("qa_data/certs/base64Cert.txt","utf-8")

$oCert = ObjCreate("Chilkat.Cert")
$bSuccess = $oCert.LoadFromBase64($oSbCertBase64.GetAsString())
If ($bSuccess = False) Then
    ConsoleWrite($oCert.LastErrorText & @CRLF)
    Exit
EndIf

; Get the public key.
$oPubKey = ObjCreate("Chilkat.PublicKey")
$oCert.GetPublicKey($oPubKey)

Local $iNumBits = $oPubKey.KeySize
ConsoleWrite("Number of bits = " & $iNumBits & @CRLF)

; If using an older version of Chilkat, the key size can be obtained like this:
$oXml = ObjCreate("Chilkat.Xml")
$oXml.LoadXml($oPubKey.GetXml())

$oBinDat = ObjCreate("Chilkat.BinData")
$oBinDat.AppendEncoded($oXml.GetChildContent("Modulus"),"base64")

$iNumBits = 8 * $oBinDat.NumBytes
ConsoleWrite("Number of bits = " & $iNumBits & @CRLF)