(Lianja) Sign a Byte Array to Create an Opaque Signature in a Byte Array

Signs data contained in a byte array to produce an opaque signature (also in a byte array). An opaque signature is a PKCS7 signature (also known as CAdES) that embeds the signed data. Also shows how to verify the signature and extract the original data.

Chilkat Lianja Extension Download Chilkat Lianja Extension

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loCert
    return
endif

loFac = createobject("CkFileAccess")

loFileBytes = loFac.ReadEntireFile("qa_data/pdf/sample.pdf")
if (loFac.LastMethodSuccess <> .T.) then
    ? loFac.LastErrorText
    release loCert
    release loFac
    return
endif

loCrypt = createobject("CkCrypt2")

llSuccess = loCrypt.SetSigningCert(loCert)

// We can sign any type of file.

loSigBytes = loCrypt.OpaqueSignBytes(loFileBytes)
if (loCrypt.LastMethodSuccess <> .T.) then
    ? loCrypt.LastErrorText
    release loCert
    release loFac
    release loCrypt
    return
endif

llSuccess = loFac.WriteEntireFile("qa_output/sample.pdf.p7m",loSigBytes)
if (loFac.LastMethodSuccess <> .T.) then
    ? loFac.LastErrorText
    release loCert
    release loFac
    release loCrypt
    return
endif

// We can verify the opaque signature and extract the original data like this

loOriginalData = loCrypt.OpaqueVerifyBytes(loSigBytes)
if (loCrypt.LastMethodSuccess <> .T.) then
    ? loCrypt.LastErrorText
    release loCert
    release loFac
    release loCrypt
    return
endif

llSuccess = loFac.WriteEntireFile("qa_output/sample.pdf",loOriginalData)
if (loFac.LastMethodSuccess <> .T.) then
    ? loFac.LastErrorText
    release loCert
    release loFac
    release loCrypt
    return
endif

? "Signature is verified and the original data was extracted."


release loCert
release loFac
release loCrypt