(Swift) 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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MAC OS X (Cocoa) Objective-C/Swift Libs

iOS Objective-C/Swift Libs

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

    let crypt = CkoCrypt2()!
    let cert = CkoCert()!

    // If loading from a smart card, set the smartcard PIN.
    cert.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..
    var success: Bool = cert.load(fromSmartcard: "")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    success = crypt.setSigning(cert)
    if success == false {
        print("\(crypt.lastErrorText!)")
        return
    }

    // 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.)
    let bd = CkoBinData()!
    success = bd.loadFile("qa_data/p7s/cosign/sample.pdf.p7s")
    if success == false {
        print("Failed to load pdf.p7s input file.")
        return
    }

    // bd2 will contain the co-signed result.
    let bd2 = CkoBinData()!
    success = crypt.coSign(bd, cert: cert, bdOut: bd2)
    if success == false {
        print("\(crypt.lastErrorText!)")
        return
    }

    success = bd.writeFile("qa_output/cosigned.pdf.p7s")
    if success == false {
        print("Failed to save pdf.p7s output file.")
        return
    }

    print("Success!")

}