From cc18a545a87ca616f05114d174690e5cc9614669 Mon Sep 17 00:00:00 2001
From: Igor Tolmachev <me@igorek.dev>
Date: Tue, 16 Jul 2024 17:24:33 +0900
Subject: Optimize encryption

- Add archive for testing encryption of compressed files
- Implement incorrect password check
- Use custom crc32 function
---
 src/zip/file/info.rs | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

(limited to 'src/zip/file/info.rs')

diff --git a/src/zip/file/info.rs b/src/zip/file/info.rs
index f5d4d8a..599dcc3 100644
--- a/src/zip/file/info.rs
+++ b/src/zip/file/info.rs
@@ -2,7 +2,7 @@ use crate::driver::ArchiveFileInfo;
 use crate::zip::{ZipError, ZipResult};
 use chrono::{DateTime, Local};
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum CompressionMethod {
     Store,
     Deflate,
@@ -28,18 +28,22 @@ impl CompressionMethod {
     }
 }
 
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum EncryptionMethod {
     None,
-    Weak,
+    Weak(u8),
     Unsupported,
 }
 
 impl EncryptionMethod {
-    pub(crate) fn from_bit_flag(bit_flag: BitFlag) -> EncryptionMethod {
+    pub(crate) fn from_bif_flag(bit_flag: BitFlag, crc: u32, dos_time: u16) -> EncryptionMethod {
         match (bit_flag.is_encrypted(), bit_flag.is_strong_encryption()) {
             (false, false) => EncryptionMethod::None,
-            (true, false) => EncryptionMethod::Weak,
+            (true, false) => EncryptionMethod::Weak(if bit_flag.is_has_data_descriptor() {
+                (dos_time >> 8) as u8 // Info-ZIP modification
+            } else {
+                (crc >> 24) as u8
+            }),
             (true, true) => EncryptionMethod::Unsupported,
             _ => panic!("impossible"),
         }
@@ -52,7 +56,7 @@ pub struct BitFlag {
 }
 
 pub mod bit {
-    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
+    #[derive(Debug, PartialEq, Eq, Clone)]
     pub enum DeflateMode {
         Normal,
         Maximum,
-- 
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