vortex-mod-mega

MEGA WASM plugin for Vortex — resolves mega.nz public file URLs and exposes the AES-128-CTR + chunk-MAC machinery the Vortex core engine needs to decrypt downloaded bytes and verify integrity.

Status

• File URL resolution (https://mega.nz/file/<id>#<key>) — done
• AES-128-CTR streaming decryption (memory-bounded, native-tested) — done
• Per-chunk CBC-MAC accumulator + final file-MAC fold — done
• MAC mismatch detection (PluginError::MacMismatch) — done
• Folder URL enumeration (https://mega.nz/folder/<id>#<key>) — done
• AES-128-ECB unwrap of per-node keys + AES-128-CBC decrypt of attribute blobs — done

Plugin contract

Plugin function	Behaviour
can_handle	"true" for any mega.nz/file/... or mega.nz/folder/... URL.
supports_playlist	"true" for folder URLs, "false" otherwise.
extract_links	File URL → JSON { kind: "file", files: [FileLink] } with EncryptionInfo. Folder URL → { kind: "folder", files: [FileLink, ...] } where each child carries a synthetic https://mega.nz/file/<h>#<k> URL and direct_url = null (host calls resolve_stream_url per child).
resolve_stream_url	File URL → encrypted CDN URL (host fetches + decrypts in-stream).

FileLink.encryption.scheme = "mega-aes128-ctr" carries the per-file AES key, IV and metaMac (all hex-encoded). Hosts must run the bytes from direct_url through MegaDecryptor::process and verify with MegaDecryptor::verify_against(meta_mac).

Build

rustup target add wasm32-wasip1
cargo build --target wasm32-wasip1 --release
sha256sum target/wasm32-wasip1/release/vortex_mod_mega.wasm
sha256sum plugin.toml

Test

cargo test                   # native unit + WASM smoke (smoke skipped if .wasm absent)
cargo test --lib crypto      # crypto round-trip + memory-bounded streaming

License

GPL-3.0