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

Visual FoxPro 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.

Download Chilkat Crypt ActiveX

LOCAL loCrypt
LOCAL lnSuccess
LOCAL lcSigningCertSubject
LOCAL lcPfxFilename
LOCAL lcPfxPassword
LOCAL loCertStore
LOCAL loCert
LOCAL lcInFile
LOCAL lcOutFile

loCrypt = CreateObject('Chilkat.Crypt2')

*  Any string argument automatically begins the 30-day trial.

lnSuccess = loCrypt.UnlockComponent("30-day trial")
IF (lnSuccess <> 1) THEN
    ? loCrypt.LastErrorText
    QUIT
ENDIF

*  Use a digital certificate and private key from a PFX file (.pfx or .p12).

lcSigningCertSubject = "Acme Inc"

lcPfxFilename = "/Users/chilkat/testData/pfx/acme.pfx"

lcPfxPassword = "test123"

loCertStore = CreateObject('Chilkat.CertStore')
lnSuccess = loCertStore.LoadPfxFile(lcPfxFilename,lcPfxPassword)
IF (lnSuccess <> 1) THEN
    ? loCertStore.LastErrorText
    QUIT
ENDIF

loCert = loCertStore.FindCertBySubjectCN(lcSigningCertSubject)
IF (loCert = NULL ) THEN
    ? "Failed to find certificate by subject common name."
    QUIT
ENDIF

*  Tell the crypt component to use this cert.
loCrypt.SetSigningCert(loCert)

*  We can sign any type of file, creating a .p7m as output:

lcInFile = "/Users/chilkat/testData/pdf/sample.pdf"

lcOutFile = "/Users/chilkat/testData/p7m/sample.pdf.p7m"
lnSuccess = loCrypt.CreateP7M(lcInFile,lcOutFile)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCert
    QUIT
ENDIF

*  Verify and restore the original file:
loCrypt.SetVerifyCert(loCert)

lcInFile = lcOutFile
lcOutFile = "/Users/chilkat/testData/pdf/restored.pdf"

lnSuccess = loCrypt.VerifyP7M(lcInFile,lcOutFile)
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    RELEASE loCert
    QUIT
ENDIF

RELEASE loCert

=MESSAGEBOX("Success!")