Merge pull request #30 from bojand/dex_dey

feat: add dex and dey support

README.md

@@ -195,6 +195,8 @@ assert_eq!(kind.extension(), "foo");
 - **bc** - `application/llvm`
 - **mach** - `application/x-mach-binary`
 - **class** - `application/java`
+- **dex** - `application/vnd.android.dex`
+- **dey** - `application/vnd.android.dey`
 
 ## Known Issues
 

src/map.rs

@@ -68,6 +68,18 @@ matcher_map!(
         "mach",
         matchers::app::is_mach
     ),
+    (
+        MatcherType::APP,
+        "application/vnd.android.dex",
+        "dex",
+        matchers::app::is_dex
+    ),
+    (
+        MatcherType::APP,
+        "application/vnd.android.dey",
+        "dey",
+        matchers::app::is_dey
+    ),
     // Image
     (
         MatcherType::IMAGE,

src/matchers/app.rs

@@ -69,3 +69,23 @@ pub fn is_mach(buf: &[u8]) -> bool {
         _ => false,
     }
 }
+
+/// Returns whether a buffer is a Dalvik Executable (DEX).
+pub fn is_dex(buf: &[u8]) -> bool {
+    // https://source.android.com/devices/tech/dalvik/dex-format#dex-file-magic
+
+    buf.len() > 36
+    // magic
+    && buf[0] == 0x64 && buf[1] == 0x65 && buf[2] == 0x78 && buf[3] == 0x0A
+    // file sise
+    && buf[36] == 0x70
+}
+
+/// Returns whether a buffer is a Dey Optimized Dalvik Executable (ODEX).
+pub fn is_dey(buf: &[u8]) -> bool {
+    buf.len() > 100
+    // magic
+    && buf[0] == 0x64 && buf[1] == 0x65 && buf[2] == 0x79 && buf[3] == 0x0A
+    // file sise
+    && is_dex(&buf[40..100])
+}

tests/app.rs

@@ -43,3 +43,7 @@ test_format!(
 );
 
 test_format!(APP, "application/wasm", "wasm", wasm, "sample.wasm");
+
+test_format!(APP, "application/vnd.android.dex", "dex", dex, "sample.dex");
+
+test_format!(APP, "application/vnd.android.dey", "dey", dey, "sample.dey");