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

Download Chilkat Crypt ActiveX

Visual Basic 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.

Dim crypt As New ChilkatCrypt2

'  Any string argument automatically begins the 30-day trial.
Dim success As Long
success = crypt.UnlockComponent("30-day trial")
If (success <> 1) Then
    MsgBox "Crypt component unlock failed"
    Exit Sub
End If

'  Find our digital certificate from the Current User certificate store.
Dim ccs As New ChilkatCreateCS
Dim certStore As ChilkatCertStore
Set certStore = ccs.OpenCurrentUserStore()
Dim cert As ChilkatCert
Set 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.CreateP7S("license.rtf","license.p7s")
If (success = 0) Then
    MsgBox crypt.LastErrorText

    Exit Sub
End If

'  Verify the signature:
crypt.SetVerifyCert cert

success = crypt.VerifyP7S("license.rtf","license.p7s")
If (success = 0) Then
    MsgBox crypt.LastErrorText

    Exit Sub
End If

MsgBox "Success!"