Verifies the signature of an S/MIME signed message
Function pkcs7_verify (filename As String, flags As Long, [outfilename], [cainfo], [extracerts]) As Boolean
pkcs7_verify() reads the S/MIME message contained in
the filename specified by filename and
examines the digital signature. It returns TRUE
if the signature is verified, FALSE if it is
not correct (the message has been tampered with, or the signing certificate is
invalid), or -1 on error.
flags can be used to affect how the
signature is verified.
If the outfilename is specified, it should
be a string holding the name of a file into which the certificates of the
persons that signed the messages will be stored in PEM format.
If the cainfo is specified, it should hold
information about the trusted CA certificates to use in the verification process
- see certificate verification for more
information about this parameter.
If the extracerts is specified, it is the
filename of a file containing a bunch of certificates to use as untrusted CAs.