Use Certificate and Private Key PEM Files to Create a Digital Signature

Demonstrates how to load a digital certificate from a PEM file, load it's corresponding private key from a PEM file, save the private key to a key container (if necessary), link the certificate to the key container, and use it to create a digital signature.

Download Chilkat Crypt ActiveX

LOCAL loCert
LOCAL loPkey
LOCAL lnSuccess
LOCAL loCrypt

loCert = CreateObject('Chilkat.Cert')

*  Load the cert from a PEM file;
loCert.LoadFromFile("cert.pem")

loPkey = CreateObject('Chilkat.PrivateKey')

*  Load the private key from an RSA PEM file:
loPkey.LoadPemFile("pkey_rsa.pem")

lnSuccess = loCert.SetPrivateKey(loPkey)
IF (lnSuccess <> 1) THEN
    ? loCert.LastErrorText
    QUIT
ENDIF

*  Use Chilkat Crypt (a non-freeware component) to create
*  a digital signature using the certificate w/ private key:
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

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

*  A PKCS7 signature for any type of file content can be created:
lnSuccess = loCrypt.CreateP7S("license.rtf","license.p7s")
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    QUIT
ENDIF

? loCrypt.LastErrorText

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

lnSuccess = loCrypt.VerifyP7S("license.rtf","license.p7s")
IF (lnSuccess = 0) THEN
    ? loCrypt.LastErrorText
    QUIT
ENDIF

=MESSAGEBOX("Success!")