Added vpk imports checking. Request by yifanlu.

Makefile

@@ -1,7 +1,7 @@
 TITLE_ID = VITASHELL
 TARGET   = VitaShell
 OBJS     = main.o init.o io_process.o makezip.o package_installer.o network_update.o context_menu.o archive.o photo.o audioplayer.o file.o text.o hex.o sfo.o \
-		   uncommon_dialog.o message_dialog.o ime_dialog.o config.o theme.o language.o utils.o sha1.o list_dialog.o UI2.o touch_shell.o \
+		   uncommon_dialog.o message_dialog.o ime_dialog.o config.o theme.o language.o utils.o elf.o sha1.o list_dialog.o UI2.o touch_shell.o \
 		   minizip/zip.o minizip/unzip.o minizip/ioapi.o bm.o audio/vita_audio.o audio/player.o audio/id3.o \
 		   audio/oggplayer.o audio/mp3player.o audio/mp3xing.o audio/lrcparse.o \
 		   libmad/bit.o libmad/decoder.o libmad/fixed.o libmad/frame.o \

archive.c

@@ -27,6 +27,8 @@ static int archive_path_start = 0;
 static unzFile uf = NULL;
 static FileList archive_list;
 
+int checkForUnsafeImports(void *buffer);
+
 int archiveCheckFilesForUnsafeFself() {
 	if (!uf)
 		return -1;
@@ -45,14 +47,38 @@ int archiveCheckFilesForUnsafeFself() {
 
 			// SCE magic
 			if (magic == 0x00454353) {
-				char buffer[0x84];
-				archiveFileRead(ARCHIVE_FD, buffer, sizeof(buffer));
+				char sce_header[0x84];
+				archiveFileRead(ARCHIVE_FD, sce_header, sizeof(sce_header));
 
-				uint64_t authid = *(uint64_t *)(buffer + 0x7C);
+				// Check authid flag
+				uint64_t authid = *(uint64_t *)(sce_header + 0x7C);
 				if (authid == 0x2F00000000000001 || authid == 0x2F00000000000003) {
 					archiveFileClose(ARCHIVE_FD);
 					return 1; // Unsafe
 				}
+
+				// Until here we have read 0x88 bytes
+				// ELF header starts at header_len, so let's seek to there
+				uint64_t header_len = *(uint64_t *)(sce_header + 0xC);
+
+				int i;
+				for (i = 0; i < header_len - 0x88; i += sizeof(uint32_t)) {
+					uint32_t dummy = 0;
+					archiveFileRead(ARCHIVE_FD, &dummy, sizeof(uint32_t));
+				}
+
+				// Check imports
+				char *buffer = malloc(archive_entry->size);
+				if (buffer) {
+					int size = archiveFileRead(ARCHIVE_FD, buffer, archive_entry->size);
+					int unsafe = checkForUnsafeImports(buffer);
+					free(buffer);
+
+					if (unsafe) {
+						archiveFileClose(ARCHIVE_FD);
+						return 1; // Unsafe
+					}
+				}
 			}
 
 			archiveFileClose(ARCHIVE_FD);

elf.c

@@ -0,0 +1,109 @@
+/*
+	VitaShell
+	Copyright (C) 2015-2016, TheFloW
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "main.h"
+#include "elf.h"
+
+typedef struct {
+	uint16_t size;
+	uint16_t lib_version;
+	uint16_t attribute;
+	uint16_t num_functions;
+	uint16_t num_vars;
+	uint16_t num_tls_vars;
+	uint32_t reserved1;
+	uint32_t module_nid;
+	char *lib_name;
+	uint32_t reserved2;
+	uint32_t func_nid_table;
+	uint32_t func_entry_table;
+	uint32_t var_nid_table;
+	uint32_t var_entry_table;
+	uint32_t tls_nid_table;
+	uint32_t tls_entry_table;
+} SceImportsTable2xx;
+
+typedef struct {
+	uint16_t size;
+	uint16_t lib_version;
+	uint16_t attribute;
+	uint16_t num_functions;
+	uint16_t num_vars;
+	uint16_t unknown1;
+	uint32_t module_nid;
+	char *lib_name;
+	uint32_t func_nid_table;
+	uint32_t func_entry_table;
+	uint32_t var_nid_table;
+	uint32_t var_entry_table;
+} SceImportsTable3xx;
+
+void convertToImportsTable3xx(SceImportsTable2xx *import_2xx, SceImportsTable3xx *import_3xx) {
+	memset(import_3xx, 0, sizeof(SceImportsTable3xx));
+
+	if (import_2xx->size == sizeof(SceImportsTable2xx)) {
+		import_3xx->size = import_2xx->size;
+		import_3xx->lib_version = import_2xx->lib_version;
+		import_3xx->attribute = import_2xx->attribute;
+		import_3xx->num_functions = import_2xx->num_functions;
+		import_3xx->num_vars = import_2xx->num_vars;
+		import_3xx->module_nid = import_2xx->module_nid;
+		import_3xx->lib_name = import_2xx->lib_name;
+		import_3xx->func_nid_table = import_2xx->func_nid_table;
+		import_3xx->func_entry_table = import_2xx->func_entry_table;
+		import_3xx->var_nid_table = import_2xx->var_nid_table;
+		import_3xx->var_entry_table = import_2xx->var_entry_table;
+	} else if (import_2xx->size == sizeof(SceImportsTable3xx)) {
+		memcpy(import_3xx, import_2xx, sizeof(SceImportsTable3xx));
+	}
+}
+
+int checkForUnsafeImports(void *buffer) {
+	Elf32_Ehdr *ehdr = (Elf32_Ehdr *)buffer;
+	Elf32_Phdr *phdr = (Elf32_Phdr *)((uint32_t)buffer + ehdr->e_phoff);
+
+	if (ehdr->e_ident[EI_MAG0] != ELFMAG0 ||
+	    ehdr->e_ident[EI_MAG1] != ELFMAG1 ||
+	    ehdr->e_ident[EI_MAG2] != ELFMAG2 ||
+	    ehdr->e_ident[EI_MAG3] != ELFMAG3) {
+		return -1;
+	}
+
+	uint32_t segment = ehdr->e_entry >> 30;
+	uint32_t offset = ehdr->e_entry & 0x3FFFFFFF;
+
+	uint32_t text_addr = (uint32_t)buffer + phdr[segment].p_offset;
+
+	SceModuleInfo *mod_info = (SceModuleInfo *)(text_addr + offset);
+
+	uint32_t i = mod_info->impTop;
+	while (i < mod_info->impBtm) {
+		SceImportsTable3xx import;
+		convertToImportsTable3xx((void *)text_addr + i, &import);
+
+		char *libname = (char *)(text_addr + import.lib_name - phdr[segment].p_vaddr);
+
+		if (strcmp(libname, "ScePromoterUtil") == 0 || strcmp(libname, "SceShellSvc") == 0) {
+			return 1; // Unsafe
+		}
+
+		i += import.size;
+	}
+
+	return 0; // Safe
+}