Sign a File to Create a .p7m File

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VB.NET 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.

Dim crypt As New Chilkat.Crypt2()

'  Any string argument automatically begins the 30-day trial.
Dim success As Boolean
success = crypt.UnlockComponent("30-day trial")
If (success <> true) Then
    MsgBox("Crypt component unlock failed")
    Exit Sub
End If


'  Find our digital certificate from the Current User certificate store.
Dim ccs As New Chilkat.CreateCS()
Dim certStore As Chilkat.CertStore
certStore = ccs.OpenCurrentUserStore()
Dim cert As Chilkat.Cert
cert = certStore.FindCertBySubjectCN("Chilkat Software, Inc.")
If (cert Is Nothing ) Then
    MsgBox(cert.LastErrorText)

    Exit Sub
End If


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



'  We can sign any type of file, creating a .p7s as output:
success = crypt.CreateP7M("test.xml","test.p7m")
If (success = false) Then
    MsgBox(crypt.LastErrorText)

    Exit Sub
End If


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

success = crypt.VerifyP7M("test.p7m","testRestored.xml")
If (success = false) Then
    MsgBox(crypt.LastErrorText)

    Exit Sub
End If




MsgBox("Success!")