PKL : Codes & Files

complete the code

The files

Filename Description
PKL.min.xml Minimal PKL (example)
PKL.xml Complete PKL (example)
PKL.template-xmlsec.sh Simple script using xmlsec1 alongside the PKL template below to be redone
PKL.template-xmlsec.xml Template PKL - without the signature and which can be used to create Digest and Signature
PKL-ST429-8.xsd Definition File (xsd) for PKL
PKL-getAssetsInfos.py Python script that retrieves asset detail

XML Validation

XML Schema reference for PKL : PKL-ST429-8.xsd

$ xmllint --noout --schema PKL-ST429-8.xsd PKL.xml PKL.xml validates

If you see validates: your PKL is syntactical perfect and valid (don't confuse with cryptographic validation)

Here is an example of a bad PKL and the error output message from xmllint :

$ xmllint --noout --schema PKL-ST429-8.xsd bad-PKL.xml bad-PKL.xml:13: element BadTag: Schemas validity error : Element '{http://www.smpte-ra.org/schemas/429-8/2007/PKL}BadTag': This element is not expected. Expected is ( {http://www.smpte-ra.org/schemas/429-8/2007/PKL}OriginalFileName ). bad-PKL.xml fails to validate

Note that the file header PKL-ST429-8.xsd integrates two imports of XSD files :

<xs:import
     namespace="http://www.w3.org/2000/09/xmldsig#"
     schemaLocation="http://www.w3.org/TR/2002/REC-xmldsig-core-20020212/xmldsig-core-schema.xsd"/>
<xs:import
     namespace="http://www.w3.org/XML/1998/namespace"
     schemaLocation="http://www.w3.org/2001/03/xml.xsd"/>

These both imports are used to validate the rest of XML schema, because PKL-ST429-8.xsd validates only the specific part of the PKL. The rest follows the XML basis standard and XML Signature standard. Therefore, the standardized XSD files will be required.

Tools such as xmllint will automatically import these files to complete their parser. However, if you don't have internet access, simply download the two files separately (xml.xsd + xmldsig-core-schema.xsd) and place them at the root directory. Then, modify the PKL-ST429-8.xsd schema to point to the local files. Example:

<xs:import
     namespace="http://www.w3.org/2000/09/xmldsig#"
     schemaLocation="xmldsig-core-schema.xsd"/>
<xs:import
     namespace="http://www.w3.org/XML/1998/namespace"
     schemaLocation="xml.xsd"/>

Get identifier (Id) of PKL

Using xmllint :

$ xmllint --xpath '//*[local-name()="PackingList"]/*[local-name()="Id"]/text()' PKL.xml
urn:uuid:ce5c22c8-a640-428c-9004-2107e1f3c94e

Using shell - short form :

$ grep -oE '<Id>urn:uuid:[A-Za-z0-9-]+</Id>' PKL.xml | head -n1 | awk -F'<|>' '{ print $3 }'
urn:uuid:ce5c22c8-a640-428c-9004-2107e1f3c94e

Using shell - long form :

$ grep -oE '<Id>urn:uuid:[A-Za-z0-9]{8}-[A-Za-z0-9]{4}-[A-Za-z0-9]{4}-[A-Za-z0-9]{4}-[A-Za-z0-9]{12}</Id>' PKL.xml | head -n1 | awk -F'<|>' '{ print $3 }'
urn:uuid:ce5c22c8-a640-428c-9004-2107e1f3c94e

Using Python :

>>> from lxml import etree
>>> with open("PKL.xml", "rb") as xml:
    tree = etree.fromstring(
        text = xml.read()
    )
    tree.xpath("/*[local-name()='PackingList']/*[local-name()='Id']/text()")
[urn:uuid:ce5c22c8-a640-428c-9004-2107e1f3c94e]

Get detail of each assets

Using xmllint :

From the element AssetList :

$ xmllint --xpath '//*[local-name()="AssetList"]//*[local-name()="Id"]/text()' PKL.xml
urn:uuid:3bd3d849-117b-46b0-bc45-3d3228c987c6
urn:uuid:3433a00f-4bc8-4c16-b33c-b0b0d65711af
urn:uuid:4aa03fde-da81-4451-baaa-4d85bf4773d0

From the element Asset :

$ xmllint --xpath '//*[local-name()="Asset"]//*[local-name()="Id"]/text()' PKL.xml
urn:uuid:3bd3d849-117b-46b0-bc45-3d3228c987c6
urn:uuid:3433a00f-4bc8-4c16-b33c-b0b0d65711af
urn:uuid:4aa03fde-da81-4451-baaa-4d85bf4773d0

From the root :

$ xmllint --xpath '//*[local-name()="Hash"]/text()' PKL.xml
hnBSgENJXOvI6bfpat7GA1VImss=
ACd4Aky39E608RNnVfAOisPICZ4=
YOdZjnEy0JynObowRG9FLXx8tD4=

Warning : in this example, with Id, you will get ALL Id from the XML file.

Using Python :

You can find the code below here : 

from lxml import etree

with open("PKL.xml", "rb") as xml:
    tree = etree.fromstring(
        text = xml.read()
    )

    # Method #1
    for element in ["Id", "AnnotationText", "Hash", "Size", "Type", "OriginalFileName"]:
        values = tree.xpath("*/*[local-name()='Asset']/*[local-name()='%s']/text()" % element)
        print(f"[assets ] {element:16s}  =  {values}")

    # Method 2
    for index, asset in enumerate(tree.xpath("*/*[local-name()='Asset']"), 1):
        for element in ["Id", "AnnotationText", "Hash", "Size", "Type", "OriginalFileName"]:
            value = asset.xpath(".//*[local-name()='%s']/text()" % element)
            print(f"[asset {index}] {element:16s}  =  {value}")
            

# == Output ============

# == Method 1 ==

# [assets ] Id                =  ['urn:uuid:3bd3d849-117b-46b0-bc45-3d3228c987c6', 'urn:uuid:3433a00f-4bc8-4c16-b33c-b0b0d65711af', 'urn:uuid:4aa03fde-da81-4451-baaa-4d85bf4773d0']
# [assets ] AnnotationText    =  ['CPL: DCP-INSIDE-CRYPTE_TST-2D-24_C_FR-XX_51_4K_20220102_SMPTE_OV']
# [assets ] Hash              =  ['hnBSgENJXOvI6bfpat7GA1VImss=', 'ACd4Aky39E608RNnVfAOisPICZ4=', 'YOdZjnEy0JynObowRG9FLXx8tD4=']
# [assets ] Size              =  ['989547', '889695', '13102']
# [assets ] Type              =  ['application/mxf', 'application/mxf', 'text/xml']
# [assets ] OriginalFileName  =  ['jp2k_3bd3d849-117b-46b0-bc45-3d3228c987c6_video.mxf', 'wav_3433a00f-4bc8-4c16-b33c-b0b0d65711af_audio.mxf', 'CPL_4aa03fde-da81-4451-baaa-4d85bf4773d0.xml']

# == Method 2 ==

# [asset 1] Id                =  ['urn:uuid:3bd3d849-117b-46b0-bc45-3d3228c987c6']
# [asset 1] AnnotationText    =  []
# [asset 1] Hash              =  ['hnBSgENJXOvI6bfpat7GA1VImss=']
# [asset 1] Size              =  ['989547']
# [asset 1] Type              =  ['application/mxf']
# [asset 1] OriginalFileName  =  ['jp2k_3bd3d849-117b-46b0-bc45-3d3228c987c6_video.mxf']
# [asset 2] Id                =  ['urn:uuid:3433a00f-4bc8-4c16-b33c-b0b0d65711af']
# [asset 2] AnnotationText    =  []
# [asset 2] Hash              =  ['ACd4Aky39E608RNnVfAOisPICZ4=']
# [asset 2] Size              =  ['889695']
# [asset 2] Type              =  ['application/mxf']
# [asset 2] OriginalFileName  =  ['wav_3433a00f-4bc8-4c16-b33c-b0b0d65711af_audio.mxf']
# [asset 3] Id                =  ['urn:uuid:4aa03fde-da81-4451-baaa-4d85bf4773d0']
# [asset 3] AnnotationText    =  ['CPL: DCP-INSIDE-CRYPTE_TST-2D-24_C_FR-XX_51_4K_20220102_SMPTE_OV']
# [asset 3] Hash              =  ['YOdZjnEy0JynObowRG9FLXx8tD4=']
# [asset 3] Size              =  ['13102']
# [asset 3] Type              =  ['text/xml']
# [asset 3] OriginalFileName  =  ['CPL_4aa03fde-da81-4451-baaa-4d85bf4773d0.xml']