Verify and Unwrap PCKS7 Signed MIME

Demonstrates calling the Verify method to verify and unwrap PKCS7 signed MIME. The MIME is restored to the original structure that it would have originally had prior to signing. The Verify method works with both detached signatures, as well as opaque/attached signatures.

Download Chilkat MIME ActiveX

LOCAL loMime
LOCAL lnSuccess
LOCAL lnVerified

loMime = CreateObject('Chilkat.Mime')

lnSuccess = loMime.UnlockComponent("Anything for 30-day trial")
IF (lnSuccess = 0) THEN
    ? loMime.LastErrorText
    QUIT
ENDIF

*  A PKCS7 signature usually embeds both the signing
*  certificate with its public key.  Therefore, it is usually
*  possible to verify a signature without the need to
*  already have the certificate installed.

*  Load the signed MIME from a file...
lnSuccess = loMime.LoadMimeFile("signedMime.txt")
IF (lnSuccess = 0) THEN
    ? loMime.LastErrorText
    QUIT
ENDIF

*  Verify the signed MIME and restore the MIME
*  to the structure/content it had prior to signing.

lnVerified = loMime.Verify()
IF (lnVerified = 0) THEN
    ? loMime.LastErrorText
    QUIT
ENDIF

*  Examine the MIME after signature verification (i.e. "unwrapping")
? loMime.GetMime()