cofra

Cofra (Irish cófra: a chest, a coffer). A zip archive read and written with no dependency at all, which is to say a box with the list of what is in it fastened inside the lid. Entries are STORED or DEFLATE and nothing else. CRC-32 is computed over every entry AS IT IS READ and checked against the directory, and a mismatch names the entry and both values rather than returning a shorter file and calling it success. Zip64, encryption and every other compression method are REFUSED BY ENTRY NAME — method 12 is named bzip2, 99 is named AES, and a method the table does not know is refused by its number rather than guessed at — because a silent skip is the one failure a container must never have. An entry with no date takes the DOS epoch, 1980-01-01, the earliest an MS-DOS date field holds, which is the whole reason the same content written twice is the same bytes twice: nothing here ever asks the clock. The reader finds the end record by scanning back for its signature and confirming its comment length lands exactly on the end of the file; it reads the central directory rather than trusting the local headers' sizes, because flag bit 3 may defer them; it slices a stored entry rather than viewing it, so one small file cannot hold a whole archive in memory behind it; a trailing slash over zero bytes is a folder marker and is skipped; and a repeated name is refused in both directions rather than resolved. THE PLATFORM PRIMITIVE IS NEVER IMPLEMENTED: the host surface names raw deflate in both directions and nothing else — no level, no strategy, no dictionary, because the moment a host may be tuned two hosts stop writing the same bytes — and two reference hosts on two unrelated machines, the platform's own CompressionStream and node:zlib, are proven byte-for-byte identical rather than promised. No keys, no passwords, no ciphers, and no verb on the surface that could hold one. No disk, no clock, no network, zero runtime dependencies.