detect legacy lzma alone streams when routing archives - #44
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abdul-khaliq-khalid wants to merge 1 commit into
Open
detect legacy lzma alone streams when routing archives#44abdul-khaliq-khalid wants to merge 1 commit into
abdul-khaliq-khalid wants to merge 1 commit into
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Archive routing keys lzma detection on the xz magic
\xfd7zXZ\x00, but the legacy alone (.lzma) container has no magic bytes andextract_lzma_contentsopens it anyway throughlzma.open's FORMAT_AUTO. A malicious pickle scores unsafe=3 raw and inside an xz stream but unsafe=0 when wrapped as a bare .lzma stream, since its contents are never routed to the lzma branch and never scanned. Addedis_lzma_alone_bytes, which validates the 13-byte alone header (properties byte, power-of-two dictionary size, uncompressed-size field), and routed the archive-detection sites through it next to the existing xz check.