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pythonzipcompressionzlibdeflate

Possible to have a password-protected/weak-encrypted ZIP file with a data descriptor?

Is it possible to have ZIP file that has a data descriptor, and so the compressed size of each file is after its data, and have it password-protected via ZIP's "weak" encryption mechanism?

Context: am working on a streaming unZIP function for Python, specifically adding decryption support. Not being able to depend on the compressed size known before the data makes it... awkward.

Solution

  • Yes.

    UEsDBC0ACQAIAPBaJFMAAPBa//////////8BABQALQEAEAAAAAAAAAAAAAAAAAAAAAAAiTFa
LaeEC1Hn3rkwrUpSKqBmSpAtoQ1LulBLBwidP2y1GQAAAAAAAAAOAAAAAAAAAFBLAQIeAy0A
CQAIAPBaJFOdP2y1GQAAAA4AAAABAAAAAAAAAAAAAACwEQAAAAAtUEsFBgAAAAABAAEALwAA
AGQAAAAAAA==

    Made with Info-ZIP's zip thusly:

    echo -n 'hello, hello!\0' | zip -e | cat > foo.zip

    (password: foo)