(Swift 3,4,5...) 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 Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

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

    let cert = CkoCert()!
    var success: Bool = cert.loadPfxFile("qa_data/pfx/cert_test123.pfx", password: "test123")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    let fac = CkoFileAccess()!

    var fileBytes: NSData
    fileBytes = fac.readEntireFile("qa_data/pdf/sample.pdf")
    if fac.lastMethodSuccess != true {
        print("\(fac.lastErrorText!)")
        return
    }

    let crypt = CkoCrypt2()!

    success = crypt.setSigning(cert)

    // We can sign any type of file.

    var sigBytes: NSData
    sigBytes = crypt.opaqueSignBytes(fileBytes)
    if crypt.lastMethodSuccess != true {
        print("\(crypt.lastErrorText!)")
        return
    }

    success = fac.writeEntireFile("qa_output/sample.pdf.p7m", fileData: sigBytes)
    if fac.lastMethodSuccess != true {
        print("\(fac.lastErrorText!)")
        return
    }

    // We can verify the opaque signature and extract the original data like this
    var originalData: NSData
    originalData = crypt.opaqueVerifyBytes(sigBytes)
    if crypt.lastMethodSuccess != true {
        print("\(crypt.lastErrorText!)")
        return
    }

    success = fac.writeEntireFile("qa_output/sample.pdf", fileData: originalData)
    if fac.lastMethodSuccess != true {
        print("\(fac.lastErrorText!)")
        return
    }

    print("Signature is verified and the original data was extracted.")

}