Dependencies

exav is a security tool, so what it links is part of its threat model. This page lists the dependencies of the shipped binary (exav, default features): the direct ones first, with what each is for, its license and its unsafe posture, then every transitive crate with the direct dependency that pulls it in. The published container image is built with http, so it also carries the opt-in dependencies. The dependency policy behind these choices is in the repository’s docs/DEPENDENCIES.md.

Memory-safety posture

• Safe Rust. Every workspace crate except the exav binary is #![forbid(unsafe_code)], so the crates that parse hostile input contain no unsafe of their own.
• Pure Rust, no C, no JIT. The default build links no C library and no native code generator. Compression (flate2 with the pure-Rust miniz_oxide backend, and pure-Rust bzip2, xz, zstd and lzma crates) and crypto are pure Rust. There is no wasmtime, Cranelift, OpenSSL or ring in the default binary.
• A network server with no network crates. The ICAP server adds no dependency: its framing, chunked decoding and Encapsulated parsing are written against std, in a module that is #![forbid(unsafe_code)], so the parsers a hostile client reaches first are exav’s own.
• unsafe in dependencies. Many dependencies use unsafe internally: SIMD byte search and hashing, OS syscalls (the daemon), and buffer handling in some decoders that read scanned bytes (lzfse_rust, ruzstd, zip, tar, delharc, goblin). exav’s own crates contain none outside the daemon’s libc calls. The tables give a count per crate, and reducing it is on the roadmap.
• Feature-gated capability. Optional features (http-scan, http-update, individual formats) pull their dependencies only when enabled (see Feature flags). The network stack is opt-in, and it is the only thing that would link a crypto library that is not pure Rust (see Opt-in dependencies).

CLI & runtime (exav)

The unsafe column is counted the same way as in the transitive table.

Crate	Purpose	License	unsafe uses
clap	Command-line argument parsing	MIT OR Apache-2.0	none (forbid)
serde_json	JSON scan-report output	MIT OR Apache-2.0	13
walkdir	Recursive directory traversal	Unlicense OR MIT	none
regex	--exclude / --include path filters	MIT OR Apache-2.0	1
libc	Syscall bindings for the prefork daemon (signals, resource limits)	MIT OR Apache-2.0	668 (FFI declarations)

Spilling an oversized object to a temp file is not a dependency: it is crates/exav/src/tmpfile.rs, a page of std::fs with the properties that matter (O_CREAT|O_EXCL, so a planted symlink cannot be followed; mode 0600; delete on drop). The ready-made crates reach the filesystem through rustix and linux-raw-sys, which would add more unsafe than the rest of the tree.

Core engine (exav-core)

The engine crate is #![forbid(unsafe_code)]; the unsafe noted below lives inside these dependencies, not in exav. The index the signature engine finds its anchors with, which also serves as YARA’s atom prefilter, is exav’s own code, not a dependency.

Crate	Purpose	License	unsafe uses
memchr	Vectorized byte search	Unlicense OR MIT	333 (SIMD)
regex	Linear-time regex (PCRE subsignatures, phishing allowlists)	MIT OR Apache-2.0	1
regex-automata / regex-syntax	Linear-time (DoS-safe) regex engine + parser (YARA regexes, the atom prefilter’s required literals)	MIT OR Apache-2.0	55 / none (forbid)
bit-set	For the backtracking regex engine vendored in exav-core (below)	Apache-2.0 OR MIT	2
goblin	PE / ELF / Mach-O executable parsing	MIT	34
md-5 / sha1 / sha2	Hash signatures (whole-file / section digests), and key derivation in decrypt	MIT OR Apache-2.0	1 / 7 / 50 (CPU-feature detection, SIMD)
crc32fast	CRC-32 (the .exavdb trailer, YARA’s hash module, archive CRCs)	MIT OR Apache-2.0	15 (SIMD)
base64	Base64 decode (YARA base64 modifiers; uuencode, email, XDP and embedded payloads in exav-unpack)	MIT OR Apache-2.0	none (forbid)
yara-x-parser	YARA grammar/AST parser (the native engine’s front end)	BSD-3-Clause	5
image	Image decoding for fuzzy_img hashing, in exav-imagehash: PNG, GIF, BMP, WebP, ICO, PNM, QOI, DDS, farbfeld and HDR itself, JPEG and TIFF through its decoders vendored there (below)	MIT OR Apache-2.0	6, plus its codecs below
zune-jpeg / zune-core	JPEG decoding for fuzzy image hashing (0.5.8, and 0.4.21 for JPEG-compressed TIFF), built without its SIMD features, which hold all of its unsafe	MIT OR Apache-2.0 OR Zlib	none (forbid) / none (two versions of each resolve)
png / gif	image’s PNG and GIF decoders, required at the versions libclamav links (as are the JPEG and TIFF ones), which cargo install would not otherwise hold	MIT OR Apache-2.0	none (forbid) / none (forbid)
hayro-jpeg2000 / hayro-jbig2	JPEG 2000 and JBIG2 decoding for fuzzy image hashing, in exav-render, built without their simd feature (fearless_simd); hayro-ccitt, below, is hayro-jbig2’s	Apache-2.0 OR MIT	none (forbid) / none (forbid)
fax / weezl / half / quick-error / bytemuck	The vendored TIFF decoder’s: CCITT fax, LZW, 16-bit floats, error types, byte casts	MIT / MIT OR Apache-2.0 / MIT OR Apache-2.0 / MIT OR Apache-2.0 / Zlib OR Apache-2.0 OR MIT	none / none (forbid) / 84 / none / 323
tlsh2	TLSH fuzzy hashing	Apache-2.0 OR BSD-3-Clause	none
rmp-serde / rmp / serde	MessagePack encoding of the prebuilt .exavdb	MIT / MIT / MIT OR Apache-2.0	none (forbid) / 1 / 2
rustc-hash	Fast hashing for internal maps (also in exav-pe-emu)	Apache-2.0 OR MIT	none
thiserror	Error-type derive	MIT OR Apache-2.0	none

Some of exav is vendored source instead of dependencies, under its crates’ forbid(unsafe_code), with what changed from upstream in a README beside it:

• exav-core’s src/fancy_regex/: fancy-regex 0.19.2 (MIT) with two fixes merged upstream after it, the backtracking engine for the PCRE subsignatures with lookaround, backreferences or atomic groups, under a step bound. Without the fixes it matches a byte above 0x7F as its UTF-8 encoding.
• exav-render’s src/image_codecs/, which exav-imagehash decodes through: image 0.25.9’s JPEG and TIFF decoders and the decoder of tiff 0.10.3 (MIT), so that zune-jpeg is built without its SIMD code, which image and tiff cannot turn off.
• exav-imagehash’s src/pillow.rs: Pillow 12.3.0’s resampler and grey conversions (MIT-CMU), ported for its imagehash preset.
• exav-imagehash’s src/dct.rs: rustdct 0.7.1’s DCT-II for power-of-two lengths (MIT), with bounds checks where upstream skips them with unsafe. Other lengths, which rustdct hands to rustfft and its SIMD code, go through a Bluestein FFT written there.

iced-x86 is not linked by any shipped binary. It is a dev-dependency of exav-x86 only, the oracle its differential tests, table generator and fuzz target check against.

Extraction & decompression (exav-unpack)

Also #![forbid(unsafe_code)]. The decoders are pure-Rust; there is no C compression library in the tree. Most of these read scanned bytes. The bzip2 decoder is not a dependency: it is vendored from bzip2-rs into formats/bzip2_rs, with a fix for incompressible blocks, and is as unsafe-free as the rest of the crate.

Crate	Purpose	License	unsafe uses
flate2	DEFLATE / gzip / zlib (pure-Rust miniz_oxide backend)	MIT OR Apache-2.0	36 (no C zlib)
deflate64	Deflate64 (ZIP method 9)	MIT	none (forbid)
xz4rust	XZ (.xz, ZIP method 95, DMG)	MIT	3
lzma-rust2	LZMA / LZMA2 (7z, lzip, ZIP method 14, SWF, NSIS, UPX, EGG)	Apache-2.0	14
ruzstd	Zstandard (pure Rust)	MIT	39
lzxd	LZX (CAB)	MIT OR Apache-2.0	none
lzfse_rust	LZFSE / LZVN (DMG)	MIT OR Apache-2.0	435
delharc	LHA / LZH	MIT OR Apache-2.0	19
bitstream-io	Bit-level readers for decoders	MIT OR Apache-2.0	none (forbid)
tar	tar archives (xattr disabled, which drops its syscall crates)	MIT OR Apache-2.0	26
zip	ZIP container parsing	MIT	32
cfb	OLE2 / Compound File Binary (Office)	MIT	none
encoding_rs	the code pages of DXF and DWG drawings before 2007, Asian double-byte ones included (features dxf, dwg), built without simd-accel	(Apache-2.0 OR MIT) AND BSD-3-Clause	193
quick-xml	OOXML / XML parsing	MIT	none (forbid)
mail-parser	MIME / email parsing	Apache-2.0 OR MIT	none (forbid)
apfs / hfsplus	DMG filesystem parsing	MIT	none
ext4-view	ext2/3/4 filesystem walking (virtual disks)	MIT OR Apache-2.0	none (forbid)
fatfs	FAT12/16/32 cluster-chain walking	MIT	11
lznt1	LZNT1 (NTFS compressed streams)	MIT	none (forbid)
salzweg	LZW (ZOO, Unix compress)	MIT	none
unshield	InstallShield .z archives	MIT	none
tinyvec	Inline vectors for the vendored bzip2 decoder	Zlib OR Apache-2.0 OR MIT	none (forbid)
byteorder	Byte-order reads	Unlicense OR MIT	40

Cryptographic primitives (the decrypt feature)

Used only to decrypt encrypted members (see Encryption support). These are RustCrypto crates; their residual unsafe is SIMD (AES-NI) and CPU-feature detection.

Crate	Purpose	License	unsafe uses
aes / cbc	AES block cipher + CBC (ZIP, 7z, PDF, DMG, Office)	MIT OR Apache-2.0	60 / none
des	Triple DES (encrypted DMG key unwrap)	MIT OR Apache-2.0	none
hmac / pbkdf2 / digest	Key derivation + MAC	MIT OR Apache-2.0	none / none / none (forbid)
constant_time_eq	Constant-time comparison	CC0-1.0 OR MIT-0 OR Apache-2.0	2
stringprep	Password normalization	MIT OR Apache-2.0	none

Opt-in dependencies (not in the default binary)

Enabled only by http-scan (URL scanning, through exav-core) or http-update (signature auto-update, through the exav-update crate); http enables both. The published container image is built with http; the release binaries are not.

Crate	Purpose	License	Note
ureq	Minimal blocking HTTP(S) client	MIT OR Apache-2.0	pulls ureq-proto, http, rustls → ring

exav-update also uses sha2 and crc32fast, which the default build already links. ring bundles C and assembly crypto; it is the one component exav can pull that is not pure Rust, which is why HTTP is off by default.

Every transitive dependency

The tables above are the crates exav chose. The real supply chain is the whole closure, so here is every remaining crate in the default exav build, with the direct dependencies that pull it in. Count the packages against the current lockfile with:

cargo tree -e no-dev -p exav --prefix none | sed 's/ (\*)$//' \
  | awk '{print $1}' | sort -u | wc -l

Seven of those are exav’s own workspace crates (exav, exav-core, exav-unpack, exav-imagehash, exav-render, exav-pe-emu, exav-x86), and a few crates resolve at two versions. None is a C library, a TLS stack or a code generator; syn, quote and proc-macro2 are build-time proc-macro machinery, and autocfg, rustc_version and semver run only in build scripts, so none of them has runtime code in the binary.

The unsafe column counts occurrences of the unsafe keyword in each crate’s shipped src/ (comments stripped; tests, benches and examples excluded) at the version resolved when the table was written. Read it as surface to review, not as risk. Most of it is in hashbrown and bytemuck, neither of which parses scanned bytes, and in zerocopy (with its derive macro), which half pulls in, and moxcms, which image does. There are no raw-syscall binding crates: rustix and linux-raw-sys are kept out by writing the spill file in-tree and by building tar without xattr. Reproduce the counts with cargo geiger, or per crate with:

find ~/.cargo/registry/src/*/<crate>-<version>/src -name '*.rs' -print0 \
  | xargs -0 sed 's://.*$::' | grep -cw unsafe

Crate	License	unsafe uses	Pulled in by
adler2	0BSD OR MIT OR Apache-2.0	none (forbid)	flate2, image, png, zip
aho-corasick	Unlicense OR MIT	227	regex, regex-automata, yara-x-parser
anstream	MIT OR Apache-2.0	3	clap
anstyle	MIT OR Apache-2.0	1	clap
anstyle-parse	MIT OR Apache-2.0	3	clap
anstyle-query	MIT OR Apache-2.0	1	clap
arraydeque	MIT/Apache-2.0	77	unshield
ascii_tree	MIT	none	yara-x-parser
beef	MIT OR Apache-2.0	26	yara-x-parser
bit-vec	Apache-2.0 OR MIT	4	bit-set
autocfg	Apache-2.0 OR MIT	none	build-time: num-traits and its users
bitflags	MIT OR Apache-2.0	21 (two versions resolve: 19 + 2)	delharc, ext4-view, fatfs, image, png, yara-x-parser
block-buffer	MIT OR Apache-2.0	21	digest, hmac, md-5, pbkdf2, sha1, sha2
block-padding	MIT OR Apache-2.0	none	aes, cbc, des
bstr	MIT OR Apache-2.0	39	yara-x-parser
byteorder-lite	Unlicense OR MIT	1	image
cfg-if	MIT OR Apache-2.0	none	crc32fast, flate2, half, image, md-5, png, sha1, sha2, tar, zip
chrono	MIT OR Apache-2.0	11	delharc
cipher	MIT OR Apache-2.0	none (forbid)	aes, cbc, des
clap_builder	MIT OR Apache-2.0	none (forbid)	clap
clap_derive	MIT OR Apache-2.0	none (forbid)	clap
clap_lex	MIT OR Apache-2.0	6	clap
cmov	Apache-2.0 OR MIT	25	digest, hmac, md-5, pbkdf2, sha1, sha2
color_quant	MIT	none	gif, image
colorchoice	MIT OR Apache-2.0	none	clap
const-oid	Apache-2.0 OR MIT	1	digest, hmac, md-5, pbkdf2, sha1, sha2
countme	MIT OR Apache-2.0	1	yara-x-parser
cpubits	MIT OR Apache-2.0	none	aes
cpufeatures	MIT OR Apache-2.0	11	aes, sha1, sha2
crc	MIT OR Apache-2.0	none (forbid)	ext4-view
crc-catalog	MIT OR Apache-2.0	none (forbid)	ext4-view
crypto-common	MIT OR Apache-2.0	none (forbid)	aes, cbc, des, digest, hmac, md-5, pbkdf2, sha1, sha2
ctutils	Apache-2.0 OR MIT	none (forbid)	digest, hmac, md-5, pbkdf2, sha1, sha2
either	MIT OR Apache-2.0	2	yara-x-parser
equivalent	Apache-2.0 OR MIT	none	mail-parser, yara-x-parser, zip
explode	MIT	5	unshield
fax_derive	MIT	none	fax
fdeflate	MIT OR Apache-2.0	none (forbid)	image, png
filetime	MIT/Apache-2.0	9	tar
fnv	Apache-2.0 / MIT	none	cfb, yara-x-parser
hashbrown	MIT OR Apache-2.0	751 (two versions resolve: 450 + 301)	mail-parser, yara-x-parser, zip
hashify	Apache-2.0 OR MIT	none	mail-parser
hayro-ccitt	Apache-2.0 OR MIT	none (forbid)	hayro-jbig2
heck	MIT OR Apache-2.0	none (forbid)	clap
hybrid-array	MIT OR Apache-2.0	37	aes, cbc, des, digest, hmac, md-5, pbkdf2, sha1, sha2
iana-time-zone	MIT OR Apache-2.0	212	delharc
image-webp	MIT OR Apache-2.0	none (forbid)	image
indexmap	Apache-2.0 OR MIT	12	mail-parser, yara-x-parser, zip
inout	MIT OR Apache-2.0	30	aes, cbc, des
is_terminal_polyfill	MIT OR Apache-2.0	none	clap
itertools	MIT OR Apache-2.0	10	yara-x-parser
itoa	MIT OR Apache-2.0	13	serde_json
lazy_static	MIT OR Apache-2.0	2	yara-x-parser
log	MIT OR Apache-2.0	6	fatfs, goblin
logos	MIT OR Apache-2.0	18	yara-x-parser
logos-codegen	MIT OR Apache-2.0	4	yara-x-parser
logos-derive	MIT OR Apache-2.0	none	yara-x-parser
miniz_oxide	MIT OR Zlib OR Apache-2.0	none (forbid; two versions resolve)	flate2, image, png, zip
moxcms	BSD-3-Clause OR Apache-2.0	344	image
no_std_io2	Apache-2.0 OR MIT	11	bitstream-io, zip
num-traits	MIT OR Apache-2.0	1	delharc, image, rmp, rmp-serde, yara-x-parser
plain	MIT/Apache-2.0	23	goblin
proc-macro2	MIT OR Apache-2.0	6	apfs, clap, fax, goblin, half, hfsplus, lznt1, mail-parser, rmp-serde, serde, thiserror, yara-x-parser
pxfm	BSD-3-Clause OR Apache-2.0	224	image
qoi	MIT/Apache-2.0	none (forbid)	image
quote	MIT OR Apache-2.0	none	apfs, clap, fax, goblin, half, hfsplus, lznt1, mail-parser, rmp-serde, serde, thiserror, yara-x-parser
rowan	MIT OR Apache-2.0	55	yara-x-parser
rustc-hash	Apache-2.0 OR MIT	none	a second version (1.x) for yara-x-parser
rustc_version	MIT OR Apache-2.0	none	build-time: yara-x-parser
same-file	Unlicense/MIT	3	walkdir
scroll	MIT	7	goblin
scroll_derive	MIT	1	goblin
semver	MIT OR Apache-2.0	47	build-time: yara-x-parser
serde_core	MIT OR Apache-2.0	2	rmp-serde, serde, serde_json
serde_derive	MIT OR Apache-2.0	none	rmp-serde, serde
simd-adler32	MIT	36	flate2, image, png, zip
strsim	MIT	none (forbid)	clap
syn	MIT OR Apache-2.0	152 (two versions resolve: 71 + 81)	apfs, clap, fax, goblin, half, hfsplus, lznt1, mail-parser, rmp-serde, serde, thiserror, yara-x-parser
text-size	MIT OR Apache-2.0	none (forbid)	yara-x-parser
thiserror-impl	MIT OR Apache-2.0	1	apfs, hfsplus, lznt1, thiserror
twox-hash	MIT	72	ruzstd
typed-path	MIT OR Apache-2.0	32	zip
typenum	MIT OR Apache-2.0	none (forbid)	aes, cbc, des, digest, hmac, md-5, pbkdf2, sha1, sha2
unicode-bidi	MIT OR Apache-2.0	1	stringprep
unicode-ident	(MIT OR Apache-2.0) AND Unicode-3.0	2	apfs, clap, fax, goblin, half, hfsplus, lznt1, mail-parser, rmp-serde, serde, thiserror, yara-x-parser
unicode-normalization	MIT OR Apache-2.0	5	stringprep
unicode-properties	MIT/Apache-2.0	none	stringprep
utf8parse	Apache-2.0 OR MIT	1	clap
uuid	Apache-2.0 OR MIT	15	cfb
web-time	MIT OR Apache-2.0	none	cfb
zerocopy	BSD-2-Clause OR Apache-2.0 OR MIT	482	half
zerocopy-derive	BSD-2-Clause OR Apache-2.0 OR MIT	807	half
zmij	MIT	70	serde_json

Verifying this yourself

Regenerate the tables above and check them:

# Direct + transitive dependencies of the default binary, with licenses.
# --no-dedupe (or --invert <crate>) is what shows every "pulled in by" edge:
cargo tree -p exav -e normal --no-dedupe --format "{p} {l}"

# Audit advisories, bans, and the license allowlist (also run in CI):
cargo deny check
cargo audit