feat: Guará 0.1.0 — recuperação de arquivos (núcleo, CLI e interface gráfica)

Núcleo em Rust somente leitura: NTFS, FAT, exFAT, partições MBR/GPT e perdidas,
carving por estrutura, fusão sem duplicatas, confiança por arquivo, imagem
forense, pausar/retomar. CLI `guara`, UI web/Tauri, CI e releases por tag.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
This commit is contained in:
Lucas RayanandClaude Sonnet 5.5 committed 2026-10-18 15:02:19 -03:00
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//! Assinaturas de formatos e validação estrutural para o carving.
//!
//! Cada detector lê a estrutura real do arquivo (cabeçalhos, blocos, rodapés)
//! para determinar o tamanho exato e o nível de confiança, em vez de apenas
//! procurar bytes mágicos.
use crate::source::{read_vec, Source};
use crate::types::{Category, Confidence};
/// Resultado de um detector: arquivo reconhecido a partir de `offset`.
#[derive(Debug, Clone)]
pub struct Hit {
pub len: u64,
pub ext: &'static str,
pub confidence: Confidence,
}
pub fn category_for_ext(ext: &str) -> Category {
match ext.to_ascii_lowercase().as_str() {
"jpg" | "jpeg" | "png" | "gif" | "bmp" | "webp" | "heic" | "avif" | "tif" | "tiff"
| "psd" | "svg" | "ico" | "cr2" | "nef" | "dng" => Category::Image,
"pdf" | "doc" | "docx" | "xls" | "xlsx" | "ppt" | "pptx" | "odt" | "ods" | "odp"
| "txt" | "rtf" | "epub" | "md" | "csv" | "html" | "xml" | "json" => Category::Document,
"mp4" | "mov" | "m4v" | "avi" | "mkv" | "webm" | "wmv" | "flv" | "mpg" | "mpeg" | "3gp" => {
Category::Video
}
"mp3" | "wav" | "flac" | "ogg" | "m4a" | "aac" | "wma" | "opus" => Category::Audio,
"zip" | "rar" | "7z" | "gz" | "tar" | "bz2" | "xz" | "jar" | "apk" => Category::Archive,
"sqlite" | "db" | "sqlite3" | "mdb" | "accdb" => Category::Database,
_ => Category::Other,
}
}
/// Verifica se o início do conteúdo é coerente com a extensão.
/// `None` = extensão sem assinatura conhecida (não dá para julgar).
pub fn matches_ext(ext: &str, head: &[u8]) -> Option<bool> {
let ext = ext.to_ascii_lowercase();
let starts = |m: &[u8]| head.starts_with(m);
let r = match ext.as_str() {
"jpg" | "jpeg" => starts(&[0xFF, 0xD8, 0xFF]),
"png" => starts(&[0x89, b'P', b'N', b'G']),
"gif" => starts(b"GIF8"),
"bmp" => starts(b"BM"),
"pdf" => starts(b"%PDF"),
"zip" | "docx" | "xlsx" | "pptx" | "odt" | "ods" | "odp" | "jar" | "epub" | "apk" => {
starts(b"PK\x03\x04") || starts(b"PK\x05\x06")
}
"doc" | "xls" | "ppt" => starts(&[0xD0, 0xCF, 0x11, 0xE0]),
"7z" => starts(&[b'7', b'z', 0xBC, 0xAF, 0x27, 0x1C]),
"rar" => starts(b"Rar!"),
"gz" => starts(&[0x1F, 0x8B]),
"mp4" | "mov" | "m4v" | "m4a" | "3gp" | "heic" | "avif" => {
head.len() >= 8 && &head[4..8] == b"ftyp"
|| (head.len() >= 8 && matches!(&head[4..8], b"moov" | b"mdat" | b"free" | b"wide"))
}
"avi" | "wav" | "webp" => starts(b"RIFF"),
"mp3" => starts(b"ID3") || (head.len() >= 2 && head[0] == 0xFF && head[1] & 0xE0 == 0xE0),
"flac" => starts(b"fLaC"),
"ogg" | "opus" => starts(b"OggS"),
"mkv" | "webm" => starts(&[0x1A, 0x45, 0xDF, 0xA3]),
"sqlite" | "sqlite3" | "db" => starts(b"SQLite format 3\0"),
"exe" | "dll" => starts(b"MZ"),
_ => return None,
};
Some(r)
}
/// Tabela de primeiros bytes -> detectores candidatos.
/// O carving consulta `candidates(first_byte)` e chama `detect`.
pub fn might_start(b0: u8) -> bool {
matches!(
b0,
0xFF | 0x89
| b'G'
| b'B'
| b'%'
| b'P'
| 0xD0
| b'7'
| b'S'
| b'R'
| b'I'
| b'M'
| 0x00
| b'f'
| 0x1F
)
}
const MAX_HEADER: usize = 64 * 1024;
/// Tenta reconhecer um arquivo que começa em `off`.
/// `head` já contém os primeiros bytes lidos em `off` (pelo menos 16, se existirem).
pub fn detect(src: &dyn Source, off: u64, head: &[u8], max_size: u64) -> Option<Hit> {
if head.len() < 12 {
return None;
}
let h = head;
if h.starts_with(&[0xFF, 0xD8, 0xFF]) {
return jpeg(src, off, max_size);
}
if h.starts_with(&[0x89, b'P', b'N', b'G', 0x0D, 0x0A, 0x1A, 0x0A]) {
return png(src, off, max_size);
}
if h.starts_with(b"GIF87a") || h.starts_with(b"GIF89a") {
return gif(src, off, max_size);
}
if h.starts_with(b"%PDF-") {
return pdf(src, off, max_size);
}
if h.starts_with(b"PK\x03\x04") {
return zip(src, off, max_size);
}
if &h[4..8] == b"ftyp" {
return isobmff(src, off, max_size);
}
if h.starts_with(b"RIFF") {
return riff(h, max_size);
}
if h.starts_with(b"BM") {
return bmp(h, max_size);
}
if h.starts_with(b"SQLite format 3\0") {
return sqlite(h, max_size);
}
if h.starts_with(&[b'7', b'z', 0xBC, 0xAF, 0x27, 0x1C]) {
return sevenz(h, max_size);
}
if h.starts_with(&[0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1]) {
return ole(src, off, max_size);
}
if h.starts_with(b"ID3") {
return mp3(src, off, max_size);
}
if h.starts_with(b"MZ") {
return pe(src, off, max_size);
}
None
}
// ---------------------------------------------------------------- JPEG
fn jpeg(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let head = read_vec(src, off, MAX_HEADER).ok()?;
let mut p = 2usize;
let mut sos_end = None;
let mut saw_sof = false;
while p + 4 <= head.len() {
if head[p] != 0xFF {
return None;
}
let m = head[p + 1];
if m == 0xFF {
p += 1;
continue;
}
if m == 0xD9 {
return Some(Hit {
len: p as u64 + 2,
ext: "jpg",
confidence: Confidence::Medium,
});
}
if (0xD0..=0xD8).contains(&m) || m == 0x01 {
p += 2;
continue;
}
let seg = u16::from_be_bytes([head[p + 2], head[p + 3]]) as usize;
if seg < 2 {
return None;
}
if matches!(m, 0xC0..=0xC3 | 0xC5..=0xC7 | 0xC9..=0xCB | 0xCD..=0xCF) {
saw_sof = true;
}
p += 2 + seg;
if m == 0xDA {
sos_end = Some(p);
break;
}
}
let start = sos_end?;
if !saw_sof {
return None;
}
// Dados entropy-coded: procurar EOI (FF D9) ignorando FF00 e RSTn.
let mut pos = off + start as u64;
let limit = off + max.min(512 * 1024 * 1024);
let mut buf = vec![0u8; 1 << 20];
let mut prev_ff = false;
while pos < limit {
let n = src.read_at(pos, &mut buf).ok()?;
if n == 0 {
break;
}
for (i, &b) in buf[..n].iter().enumerate() {
if prev_ff {
if b == 0xD9 {
return Some(Hit {
len: pos + i as u64 + 1 - off,
ext: "jpg",
confidence: Confidence::High,
});
}
prev_ff = b == 0xFF;
} else {
prev_ff = b == 0xFF;
}
}
pos += n as u64;
}
// Sem EOI: imagem truncada/sobrescrita; ainda útil, mas incerta.
Some(Hit {
len: (pos - off).min(4 * 1024 * 1024),
ext: "jpg",
confidence: Confidence::Low,
})
}
// ---------------------------------------------------------------- PNG
fn png(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let mut p = 8u64;
let mut first = true;
for _ in 0..200_000 {
let c = read_vec(src, off + p, 8).ok()?;
if c.len() < 8 {
break;
}
let len = u32::from_be_bytes([c[0], c[1], c[2], c[3]]) as u64;
let ty = &c[4..8];
if !ty.iter().all(|b| b.is_ascii_alphabetic()) || len > 0x7FFF_FFFF {
break;
}
if first && ty != b"IHDR" {
return None;
}
first = false;
p += 12 + len;
if p > max {
break;
}
if ty == b"IEND" {
return Some(Hit {
len: p,
ext: "png",
confidence: Confidence::High,
});
}
}
if first {
return None;
}
Some(Hit {
len: p.min(max).min(src.size().saturating_sub(off)),
ext: "png",
confidence: Confidence::Low,
})
}
// ---------------------------------------------------------------- GIF
fn gif(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let d = read_vec(src, off, (16usize * 1024 * 1024).min(max as usize)).ok()?;
if d.len() < 13 {
return None;
}
let flags = d[10];
let mut p = 13usize;
if flags & 0x80 != 0 {
p += 3 * (1usize << ((flags & 7) + 1));
}
while p < d.len() {
match d[p] {
0x3B => {
return Some(Hit {
len: p as u64 + 1,
ext: "gif",
confidence: Confidence::High,
})
}
0x21 => {
p += 2;
p = skip_subblocks(&d, p)?;
}
0x2C => {
if p + 10 > d.len() {
break;
}
let f = d[p + 9];
p += 10;
if f & 0x80 != 0 {
p += 3 * (1usize << ((f & 7) + 1));
}
p += 1;
p = skip_subblocks(&d, p)?;
}
_ => return None,
}
}
Some(Hit {
len: d.len() as u64,
ext: "gif",
confidence: Confidence::Low,
})
}
fn skip_subblocks(d: &[u8], mut p: usize) -> Option<usize> {
loop {
let n = *d.get(p)? as usize;
p += 1 + n;
if n == 0 {
return Some(p);
}
}
}
// ---------------------------------------------------------------- BMP
fn bmp(h: &[u8], max: u64) -> Option<Hit> {
if h.len() < 18 {
return None;
}
let size = u32::from_le_bytes([h[2], h[3], h[4], h[5]]) as u64;
let reserved = u32::from_le_bytes([h[6], h[7], h[8], h[9]]);
let dib = u32::from_le_bytes([h[14], h[15], h[16], h[17]]);
if reserved != 0
|| !matches!(dib, 12 | 40 | 52 | 56 | 64 | 108 | 124)
|| size < 26
|| size > max
{
return None;
}
Some(Hit {
len: size,
ext: "bmp",
confidence: Confidence::High,
})
}
// ---------------------------------------------------------------- PDF
fn pdf(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let limit = max.min(1 << 30);
let mut pos = off;
let mut buf = vec![0u8; 1 << 20 | 16];
let mut last_eof: Option<u64> = None;
let mut carry: Vec<u8> = Vec::new();
while pos - off < limit {
let n = src.read_at(pos, &mut buf[..(1 << 20)]).ok()?;
if n == 0 {
break;
}
let mut hay = std::mem::take(&mut carry);
let base = pos - hay.len() as u64;
hay.extend_from_slice(&buf[..n]);
let mut i = 0;
while let Some(f) = find(&hay[i..], b"%%EOF") {
let end = base + (i + f) as u64 + 5;
// Continua se logo após o %%EOF vier uma atualização incremental.
let tail = read_vec(src, end, 32).ok()?;
let rest: Vec<u8> = tail
.iter()
.copied()
.skip_while(|b| b.is_ascii_whitespace())
.collect();
let skipped = tail.len() - rest.len();
last_eof = Some(end + skipped.min(2) as u64 - off);
let more = rest.first().map(|b| b.is_ascii_digit()).unwrap_or(false)
|| rest.starts_with(b"%PDF");
if !more {
let conf = if last_eof.is_some() {
Confidence::High
} else {
Confidence::Low
};
return Some(Hit {
len: last_eof.unwrap(),
ext: "pdf",
confidence: conf,
});
}
i += f + 5;
}
let keep = hay.len().min(8);
carry = hay[hay.len() - keep..].to_vec();
pos += n as u64;
}
last_eof.map(|l| Hit {
len: l,
ext: "pdf",
confidence: Confidence::Medium,
})
}
fn find(hay: &[u8], needle: &[u8]) -> Option<usize> {
hay.windows(needle.len()).position(|w| w == needle)
}
// ---------------------------------------------------------------- ZIP & derivados
fn zip(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let limit = max.min(4 << 30);
let mut pos = off;
let mut buf = vec![0u8; 1 << 20];
let mut carry: Vec<u8> = Vec::new();
while pos - off < limit {
let n = src.read_at(pos, &mut buf).ok()?;
if n == 0 {
break;
}
let mut hay = std::mem::take(&mut carry);
let base = pos - hay.len() as u64;
hay.extend_from_slice(&buf[..n]);
let mut i = 0;
while let Some(f) = find(&hay[i..], b"PK\x05\x06") {
let at = base + (i + f) as u64;
if let Some(hit) = check_eocd(src, off, at) {
return Some(hit);
}
i += f + 4;
}
let keep = hay.len().min(3);
carry = hay[hay.len() - keep..].to_vec();
pos += n as u64;
}
None
}
fn check_eocd(src: &dyn Source, start: u64, at: u64) -> Option<Hit> {
let e = read_vec(src, at, 22).ok()?;
if e.len() < 22 {
return None;
}
let entries = u16::from_le_bytes([e[10], e[11]]) as u64;
let cd_size = u32::from_le_bytes([e[12], e[13], e[14], e[15]]) as u64;
let cd_off = u32::from_le_bytes([e[16], e[17], e[18], e[19]]) as u64;
let comment = u16::from_le_bytes([e[20], e[21]]) as u64;
if entries == 0 || cd_off + cd_size != at - start {
return None;
}
let cd = read_vec(src, start + cd_off, cd_size.min(4 << 20) as usize).ok()?;
let names = zip_names(&cd);
let ext = classify_zip(src, start, &names);
Some(Hit {
len: at - start + 22 + comment,
ext,
confidence: Confidence::High,
})
}
fn zip_names(cd: &[u8]) -> Vec<String> {
let mut out = vec![];
let mut p = 0;
while p + 46 <= cd.len() && &cd[p..p + 4] == b"PK\x01\x02" {
let n = u16::from_le_bytes([cd[p + 28], cd[p + 29]]) as usize;
let m = u16::from_le_bytes([cd[p + 30], cd[p + 31]]) as usize;
let k = u16::from_le_bytes([cd[p + 32], cd[p + 33]]) as usize;
if p + 46 + n > cd.len() {
break;
}
out.push(String::from_utf8_lossy(&cd[p + 46..p + 46 + n]).into_owned());
p += 46 + n + m + k;
if out.len() > 20_000 {
break;
}
}
out
}
fn classify_zip(src: &dyn Source, start: u64, names: &[String]) -> &'static str {
let has = |pre: &str| names.iter().any(|n| n.starts_with(pre));
if has("word/") {
"docx"
} else if has("xl/") {
"xlsx"
} else if has("ppt/") {
"pptx"
} else if names.first().map(|n| n == "mimetype").unwrap_or(false) {
// O primeiro item (sem compressão) traz o tipo MIME logo após o cabeçalho.
let head = read_vec(src, start, 256).unwrap_or_default();
let s = String::from_utf8_lossy(&head);
if s.contains("opendocument.text") {
"odt"
} else if s.contains("opendocument.spreadsheet") {
"ods"
} else if s.contains("opendocument.presentation") {
"odp"
} else if s.contains("epub+zip") {
"epub"
} else {
"zip"
}
} else if names.iter().any(|n| n == "AndroidManifest.xml") {
"apk"
} else if has("META-INF/") {
"jar"
} else {
"zip"
}
}
// ---------------------------------------------------------------- MP4 / MOV / HEIC (ISO BMFF)
fn isobmff(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let head = read_vec(src, off, 32).ok()?;
let brand = head.get(8..12)?.to_vec();
let mut p = 0u64;
let mut saw_moov = false;
let mut saw_mdat = false;
let total = src.size().saturating_sub(off);
for _ in 0..100_000 {
let b = read_vec(src, off + p, 16).ok()?;
if b.len() < 8 {
break;
}
let mut size = u32::from_be_bytes([b[0], b[1], b[2], b[3]]) as u64;
let ty = [b[4], b[5], b[6], b[7]];
let known = matches!(
&ty,
b"ftyp"
| b"moov"
| b"mdat"
| b"free"
| b"skip"
| b"wide"
| b"uuid"
| b"meta"
| b"moof"
| b"mfra"
| b"sidx"
| b"pnot"
| b"styp"
| b"pdin"
| b"junk"
);
if !known {
break;
}
if size == 1 {
if b.len() < 16 {
break;
}
size = u64::from_be_bytes(b[8..16].try_into().unwrap());
} else if size == 0 {
// Até o fim do arquivo: tamanho desconhecido.
size = total - p;
}
if size < 8 || p + size > max {
break;
}
match &ty {
b"moov" | b"moof" => saw_moov = true,
b"mdat" => saw_mdat = true,
_ => {}
}
p += size;
if p >= total {
break;
}
}
if p < 16 || !(saw_moov || saw_mdat) {
return None;
}
let ext = match &brand[..] {
b"qt " => "mov",
b"heic" | b"heix" | b"mif1" | b"msf1" | b"heim" | b"hevc" => "heic",
b"avif" | b"avis" => "avif",
b"M4A " | b"M4B " => "m4a",
b"M4V " => "m4v",
b"3gp4" | b"3gp5" | b"3gp6" | b"3g2a" => "3gp",
_ => "mp4",
};
let conf = if saw_moov && p <= total {
Confidence::High
} else {
Confidence::Low
};
Some(Hit {
len: p.min(total),
ext,
confidence: conf,
})
}
// ---------------------------------------------------------------- RIFF (AVI / WAV / WEBP)
fn riff(h: &[u8], max: u64) -> Option<Hit> {
let size = u32::from_le_bytes([h[4], h[5], h[6], h[7]]) as u64 + 8;
let ext = match &h[8..12] {
b"AVI " => "avi",
b"WAVE" => "wav",
b"WEBP" => "webp",
_ => return None,
};
if size < 16 || size > max {
return None;
}
Some(Hit {
len: size + (size & 1),
ext,
confidence: Confidence::High,
})
}
// ---------------------------------------------------------------- SQLite
fn sqlite(h: &[u8], max: u64) -> Option<Hit> {
if h.len() < 100 {
return None;
}
let ps = u16::from_be_bytes([h[16], h[17]]) as u64;
let ps = if ps == 1 { 65536 } else { ps };
if !(512..=65536).contains(&ps) || !ps.is_power_of_two() {
return None;
}
let pages = u32::from_be_bytes([h[28], h[29], h[30], h[31]]) as u64;
let change = &h[24..28];
let valid_for = &h[92..96];
if pages == 0 {
return None;
}
let len = pages * ps;
if len > max {
return None;
}
let conf = if change == valid_for {
Confidence::High
} else {
Confidence::Medium
};
Some(Hit {
len,
ext: "sqlite",
confidence: conf,
})
}
// ---------------------------------------------------------------- 7z
fn sevenz(h: &[u8], max: u64) -> Option<Hit> {
if h.len() < 32 {
return None;
}
let crc = u32::from_le_bytes([h[8], h[9], h[10], h[11]]);
if crc32(&h[12..32]) != crc {
return None;
}
let next_off = u64::from_le_bytes(h[12..20].try_into().unwrap());
let next_len = u64::from_le_bytes(h[20..28].try_into().unwrap());
let len = 32u64.checked_add(next_off)?.checked_add(next_len)?;
if len > max {
return None;
}
Some(Hit {
len,
ext: "7z",
confidence: Confidence::High,
})
}
pub fn crc32(data: &[u8]) -> u32 {
let mut crc = 0xFFFF_FFFFu32;
for &b in data {
crc ^= b as u32;
for _ in 0..8 {
crc = if crc & 1 != 0 {
(crc >> 1) ^ 0xEDB8_8320
} else {
crc >> 1
};
}
}
!crc
}
// ---------------------------------------------------------------- OLE2 (doc/xls/ppt legado)
fn ole(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let hdr = read_vec(src, off, 512).ok()?;
if hdr.len() < 512 {
return None;
}
let shift = u16::from_le_bytes([hdr[30], hdr[31]]) as u32;
if !(shift == 9 || shift == 12) {
return None;
}
let ssz = 1u64 << shift;
let n_fat = u32::from_le_bytes(hdr[44..48].try_into().unwrap()) as usize;
if n_fat == 0 || n_fat > 109 {
return None;
}
let mut last_used = 0u64;
for i in 0..n_fat {
let sec = u32::from_le_bytes(hdr[76 + i * 4..80 + i * 4].try_into().unwrap()) as u64;
let fat = read_vec(src, off + (sec + 1) * ssz, ssz as usize).ok()?;
for (j, e) in fat.chunks_exact(4).enumerate() {
let v = u32::from_le_bytes(e.try_into().unwrap());
if v != 0xFFFF_FFFF {
last_used = last_used.max(i as u64 * (ssz / 4) + j as u64);
}
}
}
let len = (last_used + 2) * ssz;
if len > max {
return None;
}
let data = read_vec(src, off, len.min(8 << 20) as usize).ok()?;
let u16s = |s: &str| -> Vec<u8> { s.encode_utf16().flat_map(|c| c.to_le_bytes()).collect() };
let ext = if find(&data, &u16s("WordDocument")).is_some() {
"doc"
} else if find(&data, &u16s("Workbook")).is_some() || find(&data, &u16s("Book")).is_some() {
"xls"
} else if find(&data, &u16s("PowerPoint Document")).is_some() {
"ppt"
} else {
"ole"
};
Some(Hit {
len,
ext,
confidence: Confidence::High,
})
}
// ---------------------------------------------------------------- MP3
fn mp3(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let h = read_vec(src, off, 10).ok()?;
if h.len() < 10 || h[3] == 0xFF || h[4] == 0xFF {
return None;
}
let tag = ((h[6] as u64 & 0x7F) << 21)
| ((h[7] as u64 & 0x7F) << 14)
| ((h[8] as u64 & 0x7F) << 7)
| (h[9] as u64 & 0x7F);
let mut p = 10 + tag;
let mut frames = 0u32;
loop {
let f = read_vec(src, off + p, 4).ok()?;
if f.len() < 4 {
break;
}
let Some(len) = mpeg_frame_len(&f) else { break };
p += len;
frames += 1;
if p > max {
break;
}
}
if frames < 20 {
return None;
}
// Possível tag ID3v1 de 128 bytes ao final.
if let Ok(t) = read_vec(src, off + p, 3) {
if t == b"TAG" {
p += 128;
}
}
Some(Hit {
len: p,
ext: "mp3",
confidence: Confidence::Medium,
})
}
fn mpeg_frame_len(h: &[u8]) -> Option<u64> {
if h[0] != 0xFF || h[1] & 0xE0 != 0xE0 {
return None;
}
let ver = (h[1] >> 3) & 3; // 3 = MPEG1, 2 = MPEG2, 0 = 2.5
let layer = (h[1] >> 1) & 3; // 1 = layer III
if ver == 1 || layer != 1 {
return None;
}
let br_idx = (h[2] >> 4) as usize;
let sr_idx = ((h[2] >> 2) & 3) as usize;
if br_idx == 0 || br_idx == 15 || sr_idx == 3 {
return None;
}
const BR1: [u32; 16] = [
0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 0,
];
const BR2: [u32; 16] = [
0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, 0,
];
const SR1: [u32; 3] = [44100, 48000, 32000];
let (br, sr, coef) = if ver == 3 {
(BR1[br_idx], SR1[sr_idx], 144)
} else {
(BR2[br_idx], SR1[sr_idx] / if ver == 2 { 2 } else { 4 }, 72)
};
let pad = ((h[2] >> 1) & 1) as u32;
Some((coef * br * 1000 / sr + pad) as u64)
}
// ---------------------------------------------------------------- PE (exe/dll)
fn pe(src: &dyn Source, off: u64, max: u64) -> Option<Hit> {
let h = read_vec(src, off, 4096).ok()?;
if h.len() < 0x40 {
return None;
}
let lfanew = u32::from_le_bytes(h[0x3C..0x40].try_into().unwrap()) as usize;
if lfanew + 24 > h.len() || &h[lfanew..lfanew + 4] != b"PE\0\0" {
return None;
}
let nsec = u16::from_le_bytes([h[lfanew + 6], h[lfanew + 7]]) as usize;
let opt = u16::from_le_bytes([h[lfanew + 20], h[lfanew + 21]]) as usize;
let mut s = lfanew + 24 + opt;
let mut end = 0u64;
for _ in 0..nsec.min(96) {
if s + 40 > h.len() {
return None;
}
let raw_size = u32::from_le_bytes(h[s + 16..s + 20].try_into().unwrap()) as u64;
let raw_ptr = u32::from_le_bytes(h[s + 20..s + 24].try_into().unwrap()) as u64;
end = end.max(raw_ptr + raw_size);
s += 40;
}
if end < 512 || end > max {
return None;
}
let ext = if u16::from_le_bytes([h[lfanew + 22], h[lfanew + 23]]) & 0x2000 != 0 {
"dll"
} else {
"exe"
};
Some(Hit {
len: end,
ext,
confidence: Confidence::Medium,
})
}