B4X Requires Chilkat v10.1.2+

Sign a File to Create a .p7m File (using a PFX)

See more Encryption Examples

_LANGUAGE_ example to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M. B4X

Dim success As Boolean = False

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

Dim crypt As ChilkatCrypt2
crypt.Initialize("crypt")

'  Use a digital certificate and private key from a PFX file (.pfx or .p12).
Dim signingCertSubject As String = "Acme Inc"
Dim pfxFilename As String = "/Users/chilkat/testData/pfx/acme.pfx"
Dim pfxPassword As String = "test123"

Dim certStore As ChilkatCertStore
certStore.Initialize
success = certStore.LoadPfxFile(pfxFilename, pfxPassword)
If success <> True Then
    Log(certStore.LastErrorText)
    Return
End If


Dim jsonCN As ChilkatJsonObject
jsonCN.Initialize
jsonCN.UpdateString("CN", signingCertSubject)

Dim cert As ChilkatCert
cert.Initialize("cert")
success = certStore.FindCert(jsonCN, cert)
If success = False Then
    Log("Failed to find certificate by subject common name.")
    Return
End If


'  Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert)

'  We can sign any type of file, creating a .p7m as output:
Dim inFile As String = "/Users/chilkat/testData/pdf/sample.pdf"
Dim outputFile As String = "/Users/chilkat/testData/p7m/sample.pdf.p7m"
success = crypt.CreateP7M(inFile, outputFile)
If success = False Then
    Log(crypt.LastErrorText)
    Return
End If


'  Verify and restore the original file:
success = crypt.SetVerifyCert(cert)

inFile = outputFile
outputFile = "/Users/chilkat/testData/pdf/restored.pdf"

success = crypt.VerifyP7M(inFile, outputFile)
If success = False Then
    Log(crypt.LastErrorText)
    Return
End If


Log("Success!")