B4X Requires Chilkat v10.1.2+

Sign a File to Create a .p7s (Detached Signature)

See more Encryption Examples

_LANGUAGE_ example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename. 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 .p7s as output:
Dim inFile As String = "/Users/chilkat/testData/pdf/sample.pdf"
Dim sigFile As String = "/Users/chilkat/testData/p7s/sample.p7s"

success = crypt.CreateP7S(inFile, sigFile)
If success = False Then
    Log(crypt.LastErrorText)
    Return
End If


success = crypt.VerifyP7S(inFile, sigFile)
If success = False Then
    Log(crypt.LastErrorText)
    Return
End If


Log("Success!")