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Chilkat2-Python

Check if a MIME Entity is Signed (S/MIME)

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Demonstrates the Chilkat Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper, including detached multipart/signed and opaque forms. It takes no arguments.

Note: The file path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own file.

Background: Before verifying a signature you need to know one is present, and this is the check. A signed S/MIME message comes in two shapes — detached (multipart/signed, signature alongside the content) and opaque (application/pkcs7-mime, content wrapped inside the signature) — and this recognizes both. Follow a true result with Verify.

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Chilkat2-Python
import sys
import chilkat2

success = False

# Demonstrates the Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper.  It takes no arguments.

mime = chilkat2.Mime()
success = mime.LoadMimeFile("qa_data/signed.eml")
if (success == False):
    print(mime.LastErrorText)
    sys.exit()

if (mime.IsSigned()):
    print("This is a signed S/MIME message.")
else:
    print("This is not a signed S/MIME message.")