Tcl

Convert a MIME Part's ASN.1 Body to XML

Demonstrates the Chilkat Mime.AsnBodyToXml method, which parses the current part's decoded body as ASN.1 DER and returns an XML representation of the ASN.1 structure. It takes no arguments.

Tip: Code to parse the returned XML can be generated at Chilkat Tools.

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: ASN.1 DER is the binary encoding behind PKCS #7/CMS structures — the signatures and encrypted blobs in S/MIME — and it is opaque to the naked eye. Rendering it as XML exposes the nested structure (content types, certificates, signer info) so you can inspect exactly what a signature or encrypted part contains. It is primarily a diagnostic and learning tool.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the Mime.AsnBodyToXml method, which parses the current part's decoded body as
#  ASN.1 DER and returns an XML representation of the ASN.1 structure.  It takes no arguments.
#  This is primarily useful for inspecting binary ASN.1 content such as PKCS #7 structures.

set mime [new_CkMime]

set success [CkMime_LoadMimeFile $mime "qa_data/pkcs7_part.p7m"]
if {$success == 0} then {
    puts [CkMime_lastErrorText $mime]
    delete_CkMime $mime
    exit
}

set asnXml [CkMime_asnBodyToXml $mime]
if {[CkMime_get_LastMethodSuccess $mime] == 0} then {
    puts [CkMime_lastErrorText $mime]
    delete_CkMime $mime
    exit
}

puts "$asnXml"
#  Code to parse this XML can be generated at Chilkat's online tool:
#  https://tools.chilkat.io/xmlParse

delete_CkMime $mime