556 lines
19 KiB
Rust
556 lines
19 KiB
Rust
use std::{env, ops::Range, vec};
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use chumsky::prelude::*;
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use quote::ToTokens;
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use text::whitespace;
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const FILES_TO_PARSE: &[&str] = &[
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"jpeg",
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"images",
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"sgml",
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"riff",
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"animation",
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"audio",
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"matroska",
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"vorbis",
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"audio",
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"msdos",
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"webassembly",
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"elf",
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"mach",
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];
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const BLACKLISTED: &[&str] = &["fuji-", "canon-", "corel-", "dicom", "garmin"];
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// remove extension entries not in this list from safe entries
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const SAFE_EXTENSIONS: &[&str] = &[
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".png", ".gif", ".jpeg", ".webp", ".avif", ".apng", ".bmp", ".tiff", ".x-icon", ".opus",
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".ogg", ".mp4", ".m4v", ".3gpp", ".mpeg", ".webm", ".aac", ".flac", ".wav",
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];
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const SAFE_WHITELISTED: &[&str] = &[
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"png", "gif", "jpeg", "webp", "avif", "apng", "bmp", "tiff", "x-icon", "opus", "ogg", "mp4",
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"m4v", "3gpp", "mpeg", "webm", "aac", "flac", "wav", "svg", "rss",
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];
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// we want to have signatures for these to be able to detect them
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const UNSAFE_WHITELISTED: &[&str] = &[
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".exe",
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".wasm",
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"elf",
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"mach",
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"javascript",
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"bios",
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"firmware",
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"driver",
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"mpegurl",
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];
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fn static_signatures() -> Vec<MIMEAssociation> {
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vec![
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MIMEAssociation {
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mime: "application/x-elf-executable".to_string().into(),
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ext: vec![".pie".to_string(), ".elf".to_string(), ".so".to_string()],
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safe: false,
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signatures: vec![FlattenedFileSignature {
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test: vec![0x7f, b'E', b'L', b'F'],
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mask: vec![0xff, 0xff, 0xff, 0xff],
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}],
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},
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MIMEAssociation {
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mime: "application/x-mach-binary".to_string().into(),
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ext: vec![".dylib".to_string(), ".bundle".to_string()],
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safe: false,
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signatures: vec![FlattenedFileSignature {
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test: vec![0xfe, 0xed, 0xfa, 0xce],
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mask: vec![0xff, 0xff, 0xff, 0xff],
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}],
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},
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MIMEAssociation {
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mime: "application/vnd.microsoft.portable-executable"
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.to_string()
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.into(),
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ext: vec![".exe".to_string(), ".dll".to_string(), ".sys".to_string()],
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safe: false,
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signatures: vec![FlattenedFileSignature {
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test: b"PE\0\0".to_vec(),
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mask: vec![0xff, 0xff, 0xff, 0xff],
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}],
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},
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]
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}
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#[derive(Debug, Clone)]
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pub enum MagicFileLine {
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Nop,
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Unknown,
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Magic {
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indent: u8,
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offset: u64,
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ty: MagicType,
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},
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AssignAttr {
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attr: String,
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value: String,
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},
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}
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#[derive(Debug, Clone)]
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pub enum MagicType {
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Unknown(String),
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Belong {
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test: Vec<u8>,
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mask: Option<Vec<u8>>,
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},
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String {
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test: Vec<u8>,
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},
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}
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pub fn parse_string_repr() -> impl Parser<char, Vec<u8>, Error = Simple<char>> {
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just('\\')
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.ignore_then(choice((
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just('\\').to(b'\\'),
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just('n').to(b'\n'),
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just('r').to(b'\r'),
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just('t').to(b'\t'),
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just('x').ignore_then(
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one_of("0123456789abcdefABCDEF")
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.repeated()
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.exactly(2)
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.map(|s| u8::from_str_radix(&s.iter().collect::<String>(), 16).unwrap()),
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),
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)))
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.or(none_of("\\").map(|c| c as u8))
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.repeated()
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.at_least(1)
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.map(|s| s.to_vec())
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.then_ignore(end())
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}
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pub fn parse_hex_repr() -> impl Parser<char, Vec<u8>, Error = Simple<char>> {
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just("0x")
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.ignore_then(
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one_of("0123456789abcdef")
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.repeated()
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.exactly(2)
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.map(|s| u8::from_str_radix(&s.iter().collect::<String>(), 16).unwrap())
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.repeated()
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.at_least(1),
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)
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.map(|s| s.to_vec())
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.then_ignore(end())
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}
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pub fn parse_magic_line() -> impl Parser<char, MagicFileLine, Error = Simple<char>> {
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choice((
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just('#')
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.then_ignore(any().repeated())
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.to(MagicFileLine::Nop),
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just('>')
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.repeated()
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.map(|i| i.len() as u8)
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.then(
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one_of("0123456789")
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.repeated()
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.at_least(1)
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.try_map(|s, span| {
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s.iter()
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.collect::<String>()
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.parse::<u64>()
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.map_err(|_| Simple::custom(span, "Failed to parse number"))
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})
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.or(just("0x").ignore_then(
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one_of("0123456789abcdefABCDEF")
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.repeated()
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.at_least(1)
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.try_map(|s, span| {
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u64::from_str_radix(&s.iter().collect::<String>(), 16)
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.map_err(|_| Simple::custom(span, "Failed to parse number"))
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}),
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)),
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)
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.then_ignore(whitespace().at_least(1))
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.then(
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none_of(" \t\n")
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.repeated()
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.at_least(1)
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.map(String::from_iter),
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)
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.then_ignore(whitespace().at_least(1))
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.then(
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none_of(" \t\n")
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.repeated()
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.at_least(1)
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.map(String::from_iter),
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)
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.try_map(|(((indent, offset), ty), rep), span: Range<usize>| {
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Ok(MagicFileLine::Magic {
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indent,
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offset,
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ty: match ty.as_str() {
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"string" => MagicType::String {
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test: parse_string_repr().parse(rep).map_err(|_| {
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Simple::custom(span, "Failed to parse string pattern")
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})?,
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},
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"belong" => MagicType::Belong {
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test: parse_hex_repr()
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.parse(rep)
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.map_err(|_| Simple::custom(span, "Failed to parse hex pattern"))?,
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mask: None,
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},
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s if s.starts_with("belong&") => {
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let mask = &s["belong&".len()..];
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let span_clone = span.clone();
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MagicType::Belong {
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test: parse_hex_repr().parse(rep).map_err(|_| {
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Simple::custom(span, "Failed to parse hex pattern")
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})?,
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mask: Some(parse_hex_repr().parse(mask).map_err(|_| {
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Simple::custom(span_clone, "Failed to parse hex pattern")
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})?),
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}
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}
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_ => MagicType::Unknown(ty),
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},
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})
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})
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.then_ignore(any().repeated()),
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just("!:")
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.ignore_then(
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one_of("abcdefghijklmnopqrstuvwxyz")
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.repeated()
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.at_least(1)
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.map(|s| s.iter().collect()),
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)
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.then_ignore(whitespace().at_least(1))
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.then(any().repeated().map(String::from_iter))
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.map(|(attr, value)| MagicFileLine::AssignAttr { attr, value }),
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))
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.then_ignore(whitespace())
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.then_ignore(end())
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}
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#[derive(Debug, Clone, PartialEq, serde::Serialize)]
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pub struct FileSignature {
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pub offset: u64,
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pub test: Vec<u8>,
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pub mask: Option<Vec<u8>>,
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}
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#[derive(Debug, Clone, PartialEq, serde::Serialize)]
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pub struct FlattenedFileSignature {
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pub test: Vec<u8>,
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pub mask: Vec<u8>,
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}
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impl FlattenedFileSignature {
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fn codegen(&self) -> impl ToTokens {
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let data = self
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.test
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.iter()
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.copied()
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.zip(self.mask.iter().copied())
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.map(|(t, m)| {
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quote::quote! {
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(#t, #m)
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}
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});
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quote::quote! {
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FlattenedFileSignature(&[#(#data),*])
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}
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}
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}
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impl From<FileSignature> for FlattenedFileSignature {
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fn from(sig: FileSignature) -> Self {
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let len = sig.test.len();
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FlattenedFileSignature {
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test: std::iter::repeat(0)
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.take(sig.offset as usize)
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.chain(sig.test)
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.collect(),
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mask: sig.mask.unwrap_or_else(|| {
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std::iter::repeat(0)
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.take(sig.offset as usize)
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.chain(std::iter::repeat(!0).take(len))
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.collect()
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}),
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}
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}
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}
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impl std::ops::BitAnd<FlattenedFileSignature> for FlattenedFileSignature {
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type Output = FlattenedFileSignature;
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fn bitand(mut self, mut rhs: FlattenedFileSignature) -> Self::Output {
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if self.test.len() < rhs.test.len() {
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std::mem::swap(&mut self, &mut rhs);
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}
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let test = self
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.test
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.iter()
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.zip(
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rhs.test
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.iter()
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.chain(std::iter::repeat(&0).take(self.test.len() - rhs.test.len())),
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)
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.map(|(a, b)| a | b)
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.collect();
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let mask = self
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.mask
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.iter()
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.zip(
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rhs.mask
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.iter()
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.chain(std::iter::repeat(&0).take(self.test.len() - rhs.test.len())),
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)
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.map(|(a, b)| a | b)
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.collect();
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FlattenedFileSignature { test, mask }
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}
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}
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#[derive(Debug, Clone, PartialEq, serde::Serialize)]
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pub struct MIMEAssociation {
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pub mime: Option<String>,
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pub ext: Vec<String>,
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pub safe: bool,
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pub signatures: Vec<FlattenedFileSignature>,
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}
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impl MIMEAssociation {
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fn codegen(&self) -> impl ToTokens {
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let mime = self.mime.as_deref().unwrap_or("");
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let ext = self.ext.first().map(|s| s.as_str()).unwrap_or("");
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let safe = self.safe;
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let signatures = self.signatures.iter().map(|s| s.codegen());
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quote::quote! {
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MIMEAssociation {
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mime: #mime,
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ext: #ext,
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safe: #safe,
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signatures: &[#(#signatures),*],
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}
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}
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}
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fn build_vec(lines: Vec<MagicFileLine>) -> Vec<MIMEAssociation> {
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let mut stack = Vec::new();
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let mut out: Vec<MIMEAssociation> = Vec::new();
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for line in lines {
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match line {
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MagicFileLine::Magic { ty, offset, indent } => match ty {
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MagicType::Belong { test, mask } => {
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stack.truncate(indent as usize);
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stack.push(FileSignature { offset, test, mask });
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}
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MagicType::String { test } => {
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stack.truncate(indent as usize);
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stack.push(FileSignature {
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offset,
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test,
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mask: None,
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});
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}
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_ => {}
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},
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MagicFileLine::AssignAttr { attr, value } => match attr.as_str() {
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"mime" if !stack.is_empty() => {
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let mime = value;
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let flattened = stack.iter().map(|sig| sig.clone().into()).fold(
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FlattenedFileSignature {
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test: Vec::new(),
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mask: Vec::new(),
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},
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|a, b| a & b,
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);
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if flattened.test.len() > 64 {
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eprintln!("Signature too long: {:?}", flattened.test.len());
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continue;
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}
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if let Some(existing) = out
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.iter_mut()
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.find(|m| m.mime.as_deref().map(|m| m == mime).unwrap_or(false))
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{
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existing.signatures.push(flattened);
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} else {
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out.push(MIMEAssociation {
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mime: Some(mime),
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safe: false,
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ext: vec![],
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signatures: vec![flattened],
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});
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}
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}
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"ext" if !stack.is_empty() => {
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let ext = value;
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let flattened = stack.iter().map(|sig| sig.clone().into()).fold(
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FlattenedFileSignature {
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test: Vec::new(),
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mask: Vec::new(),
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},
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|a, b| a & b,
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);
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if flattened.test.len() > 64 {
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eprintln!("Signature too long: {:?}", flattened.test.len());
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continue;
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}
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if let Some(existing) =
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out.iter_mut().find(|m| m.signatures.contains(&flattened))
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{
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existing
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.ext
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.extend(ext.split('/').map(|s| format!(".{}", s)))
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} else {
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out.push(MIMEAssociation {
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mime: None,
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safe: false,
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ext: ext.split('/').map(|s| format!(".{}", s)).collect(),
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signatures: vec![flattened],
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});
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}
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}
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_ => {}
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},
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_ => {}
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}
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}
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out.iter_mut().for_each(|m| {
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m.ext.sort();
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m.ext.dedup();
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m.signatures.sort_by(|a, b| a.test.cmp(&b.test));
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m.signatures.dedup();
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});
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out.dedup();
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out
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}
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}
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const BASE_DIR: &str = "submodules/file/magic/Magdir/";
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fn main() {
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let signatures = static_signatures()
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.into_iter()
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.chain(FILES_TO_PARSE.iter().flat_map(|file| {
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println!("cargo:rerun-if-changed={}", file);
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eprintln!("Using file: {}", file);
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let path = format!("{}{}", BASE_DIR, file);
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let content = std::fs::read(&path)
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.map(|v| String::from_utf8_lossy(&v).to_string())
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.unwrap();
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let lines = content
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.lines()
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.filter(|line| !line.is_empty())
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.map(|line| {
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parse_magic_line().parse(line).unwrap_or_else(|e| {
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eprintln!("Failed to parse line: {:?}", line);
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eprintln!("Error: {:?}", e);
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MagicFileLine::Unknown
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})
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})
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.collect::<Vec<_>>();
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MIMEAssociation::build_vec(lines)
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.into_iter()
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.map(|mut m| {
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if m.mime
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.as_ref()
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.map(|m| UNSAFE_WHITELISTED.iter().any(|u| m.contains(u)))
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.unwrap_or(false)
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{
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m.safe = false;
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return m;
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}
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if m.ext
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.iter()
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.any(|ext| UNSAFE_WHITELISTED.iter().any(|u| ext.contains(u)))
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{
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m.safe = false;
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return m;
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}
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if m.mime
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.as_ref()
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.map(|m| SAFE_WHITELISTED.iter().any(|w| m.contains(w)))
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.unwrap_or(false)
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{
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m.safe = true;
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}
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if m.ext
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.iter()
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.any(|ext| SAFE_WHITELISTED.iter().any(|w| ext.contains(w)))
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{
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m.safe = true;
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}
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if m.safe {
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m.ext
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.retain(|ext| SAFE_EXTENSIONS.iter().any(|s| ext.contains(s)));
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}
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m
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})
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.filter(|m| {
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if let Some(incoming) = &m.mime {
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let mime = incoming.to_lowercase();
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if BLACKLISTED.iter().any(|b| mime.contains(b)) {
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return false;
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}
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if SAFE_WHITELISTED.iter().any(|w| mime.contains(w))
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|| UNSAFE_WHITELISTED.iter().any(|u| mime.contains(u))
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{
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return true;
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}
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}
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if m.ext
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.iter()
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.any(|ext| BLACKLISTED.iter().any(|b| ext.contains(b)))
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{
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return false;
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}
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if let Some(incoming) = &m.mime {
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let mime = incoming.to_lowercase();
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if SAFE_WHITELISTED.iter().all(|w| mime.contains(w))
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|| UNSAFE_WHITELISTED.iter().any(|u| mime.contains(u))
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{
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return true;
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}
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}
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if m.ext.iter().any(|ext| {
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SAFE_WHITELISTED.iter().any(|w| ext.contains(w))
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|| UNSAFE_WHITELISTED.iter().any(|u| ext.contains(u))
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}) {
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return true;
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}
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false
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})
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}))
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.collect::<Vec<_>>();
|
|
|
|
let max_size = signatures
|
|
.iter()
|
|
.map(|s| s.signatures.iter().map(|s| s.test.len()).max().unwrap())
|
|
.max()
|
|
.unwrap();
|
|
|
|
if max_size > 128 {
|
|
panic!("Max signature size is too large: {}", max_size);
|
|
}
|
|
|
|
std::fs::write(env::var("OUT_DIR").unwrap() + "/magic.rs", {
|
|
let signatures = signatures.iter().map(|s| s.codegen());
|
|
|
|
quote::quote! {
|
|
/// Maximum size of a signature
|
|
pub const SNIFF_SIZE: usize = #max_size;
|
|
#[allow(clippy::all)]
|
|
const MAGICS: &[MIMEAssociation] = &[#(#signatures),*];
|
|
}
|
|
.into_token_stream()
|
|
.to_string()
|
|
})
|
|
.unwrap();
|
|
}
|