CommonPatcher: don't do anything if ROM is pre-patched

ChangeLog.md

@@ -16,9 +16,6 @@
 
 ### General Changes
 
-* CommonInstaller
-  * when detecting system properties also look if /vendor/build.prop exists
-
 * CommonAddon
   * sync GApps removal list with CommonInstaller
 
@@ -28,6 +25,7 @@
 * Full, microG packages
   * if the ROM is pre-patched with FAKE_PACKAGE_SIGNATURE include that permission from the default permission files
      * solves incompatibility with LineageOS for microG @Vavun
+     * function to detect whether ROM is pre-patched @ale5000
   * if the ROM includes a SetupWizard (mostly on stock), properly disable it (in Magisk Mode)
      * solves incompatibility with stock ROM SetupWizard and microg @DoR3M3
      * for System Mode installation, check the Issues section of the README on how to solve this
@@ -36,11 +34,14 @@
   * improved version of the `external_sd` init script @Vavun
 
 * CommonInstaller, CommonPatcher
+  * when detecting system properties also look if /vendor/build.prop exists
   * support both /data/adb/magisk and /data/magisk
   * remove old code regarding Magisk
 
 * CommonPatcher
   * when creating a backup of `services.jar` append `ro.build.flavor` and `ro.build.id`
+  * if the ROM is pre-patched with FAKE_PACKAGE_SIGNATURE don't do anything
+     * function to detect whether ROM is pre-patched @ale5000 
   * re-add UnifiedNlp patch by Tom Vincent
 
 * Uninstaller

CommonInstaller

@@ -706,7 +706,7 @@ gapps_destroy_artifacts () {
 }
 
 ##########################################################################################
-# Magisk Mode Installation
+# by @ale5000
 ##########################################################################################
 
 search_fake_package_signature () {

patcher/CommonPatcher

@@ -140,12 +140,11 @@ detect_bootmode () {
 }
 
 grep_prop() {
-	REGEX="${1}"
-	shift
-	FILES="${@}"
-	[ -z "${@}" ] && FILES='/system/build.prop'
-	sed -n "s/^${REGEX}=//p" ${FILES} | \
-		head -n 1
+	[ -f /vendor/build.prop ] && \
+		FILES="/system/build.prop /vendor/build.prop" || \
+		FILES="/system/build.prop"
+
+	sed -n "s/^${1}=//p" ${FILES} | head -n 1
 }
 
 grep_cmdline() {
@@ -257,16 +256,16 @@ detect_sdk () {
 	[ "${SDK_VERSION}" -lt 16 ] && \
 		error "Android versions before Jelly Bean are not supported"
 
-       if [ "${SDK_VERSION}" -gt 25 ]; then
-              BAKSMALI="${BASEDIR}/baksmali_26.dex"
-              SMALI="${BASEDIR}/smali_26.dex"
-       elif [ "${SDK_VERSION}" -gt 23 ]; then
-              BAKSMALI="${BASEDIR}/baksmali_25.dex"
-              SMALI="${BASEDIR}/smali_25.dex"
-       else
-              BAKSMALI="${BASEDIR}/baksmali_23.dex"
-              SMALI="${BASEDIR}/smali_23.dex"
-       fi
+	if [ "${SDK_VERSION}" -gt 25 ]; then
+		BAKSMALI="${BASEDIR}/baksmali_26.dex"
+		SMALI="${BASEDIR}/smali_26.dex"
+	elif [ "${SDK_VERSION}" -gt 23 ]; then
+		BAKSMALI="${BASEDIR}/baksmali_25.dex"
+		SMALI="${BASEDIR}/smali_25.dex"
+	else
+		BAKSMALI="${BASEDIR}/baksmali_23.dex"
+		SMALI="${BASEDIR}/smali_23.dex"
+	fi
 
 	PATCH_CORE="${BASEDIR}/core_services.jar.dex"
 	PATCH_UNLP="${BASEDIR}/unifiednlp_services.jar.dex"
@@ -282,6 +281,25 @@ detect_sdk () {
 	[ "${SDK_VERSION}" -gt 21 ] && DEX_OPTS="--multi-dex-threaded"
 }
 
+##########################################################################################
+# by @ale5000
+##########################################################################################
+
+search_fake_package_signature () {
+	PERMISSION=android.permission.FAKE_PACKAGE_SIGNATURE
+	PERMISSION_OD=$(echo -n "${PERMISSION}" | od -A n -t x1 | tr -d '\n' | sed -e 's/^ //g;s/ /00/g')
+	HAS_FAKESIGN=false
+
+	FW_RES_DIR="${TMPDIR}/framework-res"
+	mkdir -p "${FW_RES_DIR}"
+	unzip -o /system/framework/framework-res.apk -d "${FW_RES_DIR}"
+
+	grep -qF "${PERMISSION}" "${FW_RES_DIR}/AndroidManifest.xml" && HAS_FAKESIGN=true
+	od -A n -t x1 "${FW_RES_DIR}/AndroidManifest.xml" | tr -d ' \n' | grep -qF "${PERMISSION_OD}" && HAS_FAKESIGN=true
+
+	${HAS_FAKESIGN} && return 0 || return 1
+}
+
 ##########################################################################################
 # Magisk Functions
 ##########################################################################################

patcher/META-INF/com/google/android/update-binary

@@ -39,6 +39,8 @@ elif [ -f /data/adb/NanoDroid_Patched ]; then
 	ui_print " !! /data/adb/NanoDroid_Patched exists"
 	ui_print " !! if you want to force patching, then"
 	error    " remove this file and try again"
+elif search_fake_package_signature; then
+	error    " ROM has native signature spoofing already!"
 fi
 
 setup_patcher