Visual FoxPro

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.

Visual FoxPro

LOCAL lnSuccess
LOCAL loCrypt
LOCAL loCert
LOCAL loBd
LOCAL loBd2

lnSuccess = 0

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

loCrypt = CreateObject('Chilkat.Crypt2')
loCert = CreateObject('Chilkat.Cert')

* 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..
lnSuccess = loCert.LoadFromSmartcard("")
IF (lnSuccess = 0) THEN
    ? loCert.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
ENDIF

lnSuccess = loCrypt.SetSigningCert(loCert)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    CANCEL
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('Chilkat.BinData')
lnSuccess = loBd.LoadFile("qa_data/p7s/cosign/sample.pdf.p7s")
IF (lnSuccess = 0) THEN
    ? "Failed to load pdf.p7s input file."
    RELEASE loCrypt
    RELEASE loCert
    RELEASE loBd
    CANCEL
ENDIF

* bd2 will contain the co-signed result.
loBd2 = CreateObject('Chilkat.BinData')
lnSuccess = loCrypt.CoSign(loBd,loCert,loBd2)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCrypt
    RELEASE loCert
    RELEASE loBd
    RELEASE loBd2
    CANCEL
ENDIF

lnSuccess = loBd.WriteFile("qa_output/cosigned.pdf.p7s")
IF (lnSuccess = 0) THEN
    ? "Failed to save pdf.p7s output file."
    RELEASE loCrypt
    RELEASE loCert
    RELEASE loBd
    RELEASE loBd2
    CANCEL
ENDIF

? "Success!"

RELEASE loCrypt
RELEASE loCert
RELEASE loBd
RELEASE loBd2