Add traditional PKWARE decryption.

    - Compression and encryption may not work together
    - Password check is not yet implemented
    - Unoptimized crc32 function

1 files changed, 34 insertions, 13 deletions

diff --git a/src/zip/file/info.rs b/src/zip/file/info.rs
index 4e1b293..f5d4d8a 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, Clone)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub enum CompressionMethod {
     Store,
     Deflate,
@@ -10,31 +10,49 @@ pub enum CompressionMethod {
     Lzma,
     Zstd,
     Xz,
-    Unsupported,
+    Unsupported(u16),
 }
 
 impl CompressionMethod {
     pub(crate) fn from_struct_id(id: u16) -> ZipResult<Self> {
-        match id {
-            0 => Ok(Self::Store),
-            8 => Ok(Self::Deflate),
-            12 => Ok(Self::BZip2),
-            14 => Ok(Self::Lzma),
-            93 => Ok(Self::Zstd),
-            95 => Ok(Self::Xz),
-            1..=7 | 9..=11 | 13 | 15..=20 | 94 | 96..=99 => Ok(Self::Unsupported),
-            21..=92 | 100.. => Err(ZipError::InvalidCompressionMethod.into()),
+        Ok(match id {
+            0 => Self::Store,
+            8 => Self::Deflate,
+            12 => Self::BZip2,
+            14 => Self::Lzma,
+            93 => Self::Zstd,
+            95 => Self::Xz,
+            1..=7 | 9..=11 | 13 | 15..=20 | 94 | 96..=99 => Self::Unsupported(id),
+            21..=92 | 100.. => return Err(ZipError::InvalidCompressionMethod(id).into()),
+        })
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum EncryptionMethod {
+    None,
+    Weak,
+    Unsupported,
+}
+
+impl EncryptionMethod {
+    pub(crate) fn from_bit_flag(bit_flag: BitFlag) -> EncryptionMethod {
+        match (bit_flag.is_encrypted(), bit_flag.is_strong_encryption()) {
+            (false, false) => EncryptionMethod::None,
+            (true, false) => EncryptionMethod::Weak,
+            (true, true) => EncryptionMethod::Unsupported,
+            _ => panic!("impossible"),
         }
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub struct BitFlag {
     flag: u16,
 }
 
 pub mod bit {
-    #[derive(Debug, PartialEq, Eq)]
+    #[derive(Debug, PartialEq, Eq, Clone, Copy)]
     pub enum DeflateMode {
         Normal,
         Maximum,
@@ -123,6 +141,7 @@ impl BitFlag {
 #[derive(Debug, Clone)]
 pub struct ZipFileInfo {
     pub compression_method: CompressionMethod,
+    pub encryption_method: EncryptionMethod,
     pub bit_flag: BitFlag,
     pub mtime: DateTime<Local>,
     pub atime: Option<DateTime<Local>>,
@@ -138,6 +157,7 @@ pub struct ZipFileInfo {
 impl ZipFileInfo {
     pub fn new(
         compression_method: CompressionMethod,
+        encryption_method: EncryptionMethod,
         bit_flag: BitFlag,
         mtime: DateTime<Local>,
         atime: Option<DateTime<Local>>,
@@ -151,6 +171,7 @@ impl ZipFileInfo {
     ) -> Self {
         Self {
             compression_method,
+            encryption_method,
             bit_flag,
             mtime,
             atime,