(Lianja) Get a Certificate's Key Size

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

Chilkat Lianja Extension Download Chilkat Lianja Extension

//  For this example, I have a certificate in raw base64 format (not PEM),
//  that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
loSbCertBase64 = createobject("CkStringBuilder")
llSuccess = loSbCertBase64.LoadFile("qa_data/certs/base64Cert.txt","utf-8")

loCert = createobject("CkCert")
llSuccess = loCert.LoadFromBase64(loSbCertBase64.GetAsString())
if (llSuccess <> .T.) then
    ? loCert.LastErrorText
    release loSbCertBase64
    release loCert
    return
endif

//  Get the public key.
loPubKey = loCert.ExportPublicKey()
if (loCert.LastMethodSuccess <> .T.) then
    ? loCert.LastErrorText
    release loSbCertBase64
    release loCert
    return
endif

//  In Chilkat version v9.5.0.67, the KeySize property was added.
lnNumBits = loPubKey.KeySize
? "Number of bits = " + str(lnNumBits)

//  If using an older version of Chilkat, the key size can be obtained like this:
loXml = createobject("CkXml")
loXml.LoadXml(loPubKey.GetXml())

loBinDat = createobject("CkBinData")
loBinDat.AppendEncoded(loXml.GetChildContent("Modulus"),"base64")

lnNumBits = 8 * loBinDat.NumBytes
? "Number of bits = " + str(lnNumBits)

release loPubKey


release loSbCertBase64
release loCert
release loXml
release loBinDat