Zip-align exported APK

1 files changed, 100 insertions, 12 deletions

diff --git a/platform/android/export/export.cpp b/platform/android/export/export.cpp
index 069edb7975..b35e3a8055 100644
--- a/platform/android/export/export.cpp
+++ b/platform/android/export/export.cpp
@@ -9,6 +9,7 @@
 #include "os/file_access.h"
 #include "os/os.h"
 #include "platform/android/logo.h"
+#include <string.h>
 
 
 static const char* android_perms[]={
@@ -1069,7 +1070,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 
 	String src_apk;
 
-	EditorProgress ep("export","Exporting for Android",104);
+	EditorProgress ep("export","Exporting for Android",105);
 
 	if (p_debug)
 		src_apk=custom_debug_package;
@@ -1109,7 +1110,8 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 	zlib_filefunc_def io2=io;
 	FileAccess *dst_f=NULL;
 	io2.opaque=&dst_f;
-	zipFile	apk=zipOpen2(p_path.utf8().get_data(),APPEND_STATUS_CREATE,NULL,&io2);
+	String unaligned_path=EditorSettings::get_singleton()->get_settings_path()+"/tmp/tmpexport-unaligned.apk";
+	zipFile	unaligned_apk=zipOpen2(unaligned_path.utf8().get_data(),APPEND_STATUS_CREATE,NULL,&io2);
 
 
 	while(ret==UNZ_OK) {
@@ -1192,7 +1194,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 			// Respect decision on compression made by AAPT for the export template
 			const bool uncompressed = info.compression_method == 0;
 
-			zipOpenNewFileInZip(apk,
+			zipOpenNewFileInZip(unaligned_apk,
 				file.utf8().get_data(),
 				NULL,
 				NULL,
@@ -1203,8 +1205,8 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 				uncompressed ? 0 : Z_DEFLATED,
 				Z_DEFAULT_COMPRESSION);
 
-			zipWriteInFileInZip(apk,data.ptr(),data.size());
-			zipCloseFileInZip(apk);
+			zipWriteInFileInZip(unaligned_apk,data.ptr(),data.size());
+			zipCloseFileInZip(unaligned_apk);
 		}
 
 		ret = unzGoToNextFile(pkg);
@@ -1261,7 +1263,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 
 			APKExportData ed;
 			ed.ep=&ep;
-			ed.apk=apk;
+			ed.apk=unaligned_apk;
 
 			err = export_project_files(save_apk_file,&ed,false);
 		}
@@ -1290,7 +1292,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 			print_line(itos(i)+" param: "+cl[i]);
 		}
 
-		zipOpenNewFileInZip(apk,
+		zipOpenNewFileInZip(unaligned_apk,
 			"assets/_cl_",
 			NULL,
 			NULL,
@@ -1301,12 +1303,12 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 			0, // No compress (little size gain and potentially slower startup)
 			Z_DEFAULT_COMPRESSION);
 
-		zipWriteInFileInZip(apk,clf.ptr(),clf.size());
-		zipCloseFileInZip(apk);
+		zipWriteInFileInZip(unaligned_apk,clf.ptr(),clf.size());
+		zipCloseFileInZip(unaligned_apk);
 
 	}
 
-	zipClose(apk,NULL);
+	zipClose(unaligned_apk,NULL);
 	unzClose(pkg);
 
 	if (err) {
@@ -1363,7 +1365,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 		args.push_back(keystore);
 		args.push_back("-storepass");
 		args.push_back(password);
-		args.push_back(p_path);
+		args.push_back(unaligned_path);
 		args.push_back(user);
 		int retval;
 		int err = OS::get_singleton()->execute(jarsigner,args,true,NULL,NULL,&retval);
@@ -1376,7 +1378,7 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 
 		args.clear();
 		args.push_back("-verify");
-		args.push_back(p_path);
+		args.push_back(unaligned_path);
 		args.push_back("-verbose");
 
 		err = OS::get_singleton()->execute(jarsigner,args,true,NULL,NULL,&retval);
@@ -1386,6 +1388,92 @@ Error EditorExportPlatformAndroid::export_project(const String& p_path, bool p_d
 		}
 
 	}
+
+
+
+	// Let's zip-align (must be done after signing)
+
+	static const int ZIP_ALIGNMENT = 4;
+
+	ep.step("Aligning APK..",105);
+
+	unzFile tmp_unaligned = unzOpen2(unaligned_path.utf8().get_data(), &io);
+	if (!tmp_unaligned) {
+
+		EditorNode::add_io_error("Could not find temp unaligned APK.");
+		return ERR_FILE_NOT_FOUND;
+	}
+
+	ERR_FAIL_COND_V(!tmp_unaligned, ERR_CANT_OPEN);
+	ret = unzGoToFirstFile(tmp_unaligned);
+
+	io2=io;
+	dst_f=NULL;
+	io2.opaque=&dst_f;
+	zipFile	final_apk=zipOpen2(p_path.utf8().get_data(),APPEND_STATUS_CREATE,NULL,&io2);
+
+	// Take files from the unaligned APK and write them out to the aligned one
+	// in raw mode, i.e. not uncompressing and recompressing, aligning them as needed,
+	// following what is done in https://github.com/android/platform_build/blob/master/tools/zipalign/ZipAlign.cpp
+	int bias = 0;
+	while(ret==UNZ_OK) {
+
+		unz_file_info info;
+		memset(&info, 0, sizeof(info));
+
+		char fname[16384];
+		char extra[16384];
+		ret = unzGetCurrentFileInfo(tmp_unaligned,&info,fname,16384,extra,16384-ZIP_ALIGNMENT,NULL,0);
+
+		String file=fname;
+
+		Vector<uint8_t> data;
+		data.resize(info.compressed_size);
+
+		// read
+		int method, level;
+		unzOpenCurrentFile2(tmp_unaligned, &method, &level, 1); // raw read
+		long file_offset = unzGetCurrentFileZStreamPos64(tmp_unaligned);
+		unzReadCurrentFile(tmp_unaligned,data.ptr(),data.size());
+		unzCloseCurrentFile(tmp_unaligned);
+
+		// align
+		int padding = 0;
+		if (!info.compression_method) {
+			// Uncompressed file => Align
+			long new_offset = file_offset + bias;
+            padding = (ZIP_ALIGNMENT - (new_offset % ZIP_ALIGNMENT)) % ZIP_ALIGNMENT;
+		}
+
+		memset(extra + info.size_file_extra, 0, padding);
+
+		// write
+		zipOpenNewFileInZip2(final_apk,
+			file.utf8().get_data(),
+			NULL,
+			extra,
+			info.size_file_extra + padding,
+			NULL,
+			0,
+			NULL,
+			method,
+			level,
+			1); // raw write
+		zipWriteInFileInZip(final_apk,data.ptr(),data.size());
+		zipCloseFileInZipRaw(final_apk,info.uncompressed_size,info.crc);
+
+		bias += padding;
+
+		ret = unzGoToNextFile(tmp_unaligned);
+	}
+
+	zipClose(final_apk,NULL);
+	unzClose(tmp_unaligned);
+
+	if (err) {
+		return err;
+	}
+
 	return OK;
 
 }