(Xojo Plugin) 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 Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim cert As New Chilkat.Cert
Dim success As Boolean
success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
If (success = False) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

Dim fac As New Chilkat.FileAccess

Dim fileBytes As MemoryBlock
fileBytes = fac.ReadEntireFile("qa_data/pdf/sample.pdf")
If (fac.LastMethodSuccess <> True) Then
    System.DebugLog(fac.LastErrorText)
    Return
End If

Dim crypt As New Chilkat.Crypt2

success = crypt.SetSigningCert(cert)

// We can sign any type of file.

Dim sigBytes As MemoryBlock
sigBytes = crypt.OpaqueSignBytes(fileBytes)
If (crypt.LastMethodSuccess <> True) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

success = fac.WriteEntireFile("qa_output/sample.pdf.p7m",sigBytes)
If (fac.LastMethodSuccess <> True) Then
    System.DebugLog(fac.LastErrorText)
    Return
End If

// We can verify the opaque signature and extract the original data like this
Dim originalData As MemoryBlock
originalData = crypt.OpaqueVerifyBytes(sigBytes)
If (crypt.LastMethodSuccess <> True) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

success = fac.WriteEntireFile("qa_output/sample.pdf",originalData)
If (fac.LastMethodSuccess <> True) Then
    System.DebugLog(fac.LastErrorText)
    Return
End If

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