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use core::convert::TryInto;
use super::compare_bytes;
#[allow(clippy::upper_case_acronyms)]
#[derive(Debug, Eq, PartialEq)]
enum DocType {
DOC,
DOCX,
XLS,
XLSX,
PPT,
PPTX,
OOXML,
}
pub fn is_doc(buf: &[u8]) -> bool {
ole2(buf) == Some(DocType::DOC)
}
pub fn is_docx(buf: &[u8]) -> bool {
msooxml(buf) == Some(DocType::DOCX)
}
pub fn is_xls(buf: &[u8]) -> bool {
ole2(buf) == Some(DocType::XLS)
}
pub fn is_xlsx(buf: &[u8]) -> bool {
msooxml(buf) == Some(DocType::XLSX)
}
pub fn is_ppt(buf: &[u8]) -> bool {
ole2(buf) == Some(DocType::PPT)
}
pub fn is_pptx(buf: &[u8]) -> bool {
msooxml(buf) == Some(DocType::PPTX)
}
fn msooxml(buf: &[u8]) -> Option<DocType> {
let signature = [b'P', b'K', 0x03, 0x04];
if !compare_bytes(buf, &signature, 0) {
return None;
}
let v = check_msooml(buf, 0x1E);
if v.is_some() {
return v;
}
if !compare_bytes(buf, b"[Content_Types].xml", 0x1E)
&& !compare_bytes(buf, b"_rels/.rels", 0x1E)
&& !compare_bytes(buf, b"docProps", 0x1E)
{
return None;
}
let mut start_offset = match u32::from_le_bytes(buf[18..22].try_into().unwrap()).checked_add(49)
{
Some(int) => int as usize,
None => return None,
};
let idx = search(buf, start_offset, 6000)?;
start_offset += idx + 4 + 26;
let idx = search(buf, start_offset, 6000)?;
start_offset += idx + 4 + 26;
check_msooml(buf, start_offset)?;
start_offset += 26;
let idx = search(buf, start_offset, 6000);
match idx {
Some(idx) => start_offset += idx + 4 + 26,
None => return Some(DocType::OOXML),
};
let typo = check_msooml(buf, start_offset);
if typo.is_some() {
return typo;
}
Some(DocType::OOXML)
}
#[cfg(feature = "std")]
fn ole2(buf: &[u8]) -> Option<DocType> {
use std::io::Cursor;
if !compare_bytes(buf, &[0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1], 0) {
return None;
}
if let Ok(file) = cfb::CompoundFile::open(Cursor::new(buf)) {
return match file.root_entry().clsid().to_string().as_str() {
"00020810-0000-0000-c000-000000000046" | "00020820-0000-0000-c000-000000000046" => {
Some(DocType::XLS)
}
"00020906-0000-0000-c000-000000000046" => Some(DocType::DOC),
"64818d10-4f9b-11cf-86ea-00aa00b929e8" => Some(DocType::PPT),
_ => None,
};
}
None
}
#[cfg(not(feature = "std"))]
fn ole2(buf: &[u8]) -> Option<DocType> {
if !compare_bytes(buf, &[0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1], 0) {
return None;
}
Some(DocType::DOC)
}
fn check_msooml(buf: &[u8], offset: usize) -> Option<DocType> {
if compare_bytes(buf, &[b'w', b'o', b'r', b'd', b'/'], offset) {
Some(DocType::DOCX)
} else if compare_bytes(buf, &[b'p', b'p', b't', b'/'], offset) {
Some(DocType::PPTX)
} else if compare_bytes(buf, &[b'x', b'l', b'/'], offset) {
Some(DocType::XLSX)
} else {
None
}
}
fn search(buf: &[u8], start: usize, range: usize) -> Option<usize> {
let length = buf.len();
let mut end = start + range;
let signature: &[_] = &[b'P', b'K', 0x03, 0x04];
if end > length {
end = length;
}
if start >= end {
return None;
}
buf[start..end]
.windows(signature.len())
.position(|window| window == signature)
}