(Lianja) CoSign PKCS7/CMS Signed Data

See more Digital Signatures Examples

Demonstrates how to add a 2nd signature to a CMS SignedData. This is to add an additional signature, SignerInfo and certificate(s) to an existing CMS signed data.

In this example, we cosign an existing pdf.p7s

Note: The CoSign method is added in Chilkat v9.5.0.89.

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

loCrypt = createobject("CkCrypt2")
loCert = createobject("CkCert")

// If loading from a smart card, set the smartcard PIN.
loCert.SmartCardPin = "0000"

// Load a certificate in some way, such as from a smart card.
// Chilkat provides other methods to load from a .pfx, .pem, or from the Windows certificate stores..
llSuccess = loCert.LoadFromSmartcard("")
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loCrypt
    release loCert
    return
endif

llSuccess = loCrypt.SetSigningCert(loCert)
if (llSuccess = .F.) then
    ? loCrypt.LastErrorText
    release loCrypt
    release loCert
    return
endif

// Load the file to be co-signed.
// NOTE:  This is to cosign a PDF file contained within a CMS (PKCS7) message.
// (In other words, the PDF is contained within the CMS SignedData, rather than the other way around
// where a CMS signature is contained within a PDF.  Use Chilkat's PDF class to sign a PDF, which is
// to embed a CMS signature within the PDF.)
loBd = createobject("CkBinData")
llSuccess = loBd.LoadFile("qa_data/p7s/cosign/sample.pdf.p7s")
if (llSuccess = .F.) then
    ? "Failed to load pdf.p7s input file."
    release loCrypt
    release loCert
    release loBd
    return
endif

// bd2 will contain the co-signed result.
loBd2 = createobject("CkBinData")
llSuccess = loCrypt.CoSign(loBd,loCert,loBd2)
if (llSuccess = .F.) then
    ? loCrypt.LastErrorText
    release loCrypt
    release loCert
    release loBd
    release loBd2
    return
endif

llSuccess = loBd.WriteFile("qa_output/cosigned.pdf.p7s")
if (llSuccess = .F.) then
    ? "Failed to save pdf.p7s output file."
    release loCrypt
    release loCert
    release loBd
    release loBd2
    return
endif

? "Success!"


release loCrypt
release loCert
release loBd
release loBd2