yaad

#!/usr/bin/env bash

# Copyright (c) 2016 Feilong Wang
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


prog="$0"
while [ -h "${prog}" ]; do
    newProg=`/bin/ls -ld "${prog}"`
    echo ${newProg}

    newProg=`expr "${newProg}" : ".* -> \(.*\)$"`
    if expr "x${newProg}" : 'x/' >/dev/null; then
        prog="${newProg}"
    else
        progdir=`dirname "${prog}"`
        prog="${progdir}/${newProg}"
    fi
done
oldwd=`pwd`
progdir=`dirname "${prog}"`
cd "${progdir}"
progdir=`pwd`
prog="${progdir}"/`basename "${prog}"`
cd "${oldwd}"


APKTOOL="${progdir}/apktool/apktool"
SMALITOOL="${progdir}/smali4dex/smali"
BAKSMALITOOL="${progdir}/smali4dex/baksmali"
DEX2JARTOOL="${progdir}/dex2jar/d2j-dex2jar.sh"	
JAR2JAVATOOL="${progdir}/jad/jad"


yaad_usage() {
cat <<EOF

Decompile a android apk, framework jar or a optimized apk/odex.

Usage: yaad [options] <apk|jar|odex>

  -s, --system=<directory>     
                    The directory to look for framework odex files when decomile
                    a odex file. Defaults to the YAADROOT/system directory.

  -h, --help        Print this help and exit

To decompile a odex file, it also needs a few of framework odex files. What
framework odex files needed depend on the optimized apk you are decompiling.
The most used framework odex files are android.policy.odex, bouncycastle.odex,
core.odex, pm.odex, core-junit.odex, ext.odex, services.odex, which you can
pull from /system/framework directory in the device at which your optimized
apk is compiled armed. YAAD will give you tips when needed framework odexs 
not fond.

Output
  All files are saved in the directory named <apk|jar|odex> in current directory.

  src.jar                 Source code formed in jar, open it with jd-gui
  src/                    Source code formed in java
  res/                    Resoures and so on
  AndroidManifest.xml     Android manifest file

Examples
  yaad framework-res.apk
  yaad service.jar
  yaad -s .. Launcher.odex

EOF
}

yaad_dex2code() {
	echo 
	echo "PHASE : Dex2code"
	echo
	local dex=classes.dex
	if [ -n "$1" ]; then
		dex="$1"
	fi

	"$DEX2JARTOOL" "$dex" -o src.jar -ts -f
	
	if [ $? != 0 ]; then
		echo "Decompile to jar FAILED."
		return 1
	fi

	rm -rf tree

	echo "jad $(pwd)/src.jar -> src/"
	unzip -q src.jar -d tree
	"$JAR2JAVATOOL" -o -r -ff -dead -sjava -dsrc tree/**/*.class 2>/dev/null
	local ret=$?
	rm -rf tree
	return "$ret"
}

yaad_reverse_apk() {
	if [ -z "$FILENAME" ]; then
		echo "Error: file name is NULL."
		return 1;
	fi
	
	if [ -e "$FILENAME" ]; then
		rm -rf "$FILENAME"
		if [ $? != 0 ]; then
			echo "Error: delete $FILENAME FAILED."
			return 1
		fi
	fi

	echo
	echo "PHASE : Decompile resources"
	echo

	# Decompile resources
	"$APKTOOL" d -s "$FILEPATH" "$FILENAME"

	if [ $? != 0 ]; then
		echo
		echo "Decompile resources FAILED."
	fi

	if [ ! -e "$FILENAME" ]; then
		# Decompile resoures failed.
		mkdir "$FILENAME"
	fi

	echo
	echo "PHASE : Decompile code"
	echo

	# local oldPos=`pwd`
	cd "$FILENAME"
	# Decompile code 
	unzip -q -o "$FILEPATH" classes.dex

	if [ $? != 0 ]; then
		# May be error or built with user tag.
		# echo "classes.dex not found."

		local pOdexFile=
		for tf in `ls "${FILEPATH%.*}".*`
		do
			# FIXME This should be $FILENAME.odex.
			if expr "$tf" : '.*\.\([oO][dD][eE][xX]\)$' > /dev/null; then
				pOdexFile="$tf"
				break;
			fi
		done
		if [ -r "$pOdexFile" ]; then
			yaad_reverse_odex "$pOdexFile"
			return $?
		fi

		echo
		echo "$FILENAME.odex not found."
		echo "Decompile code FAILED."
		return 1
	else
		local pDexFile=`pwd`/classes.dex
		yaad_dex2code "$pDexFile"
		local ret=$?
		rm classes.dex
		return "$ret"
	fi

	# cd ${oldPos}
	
}

yaad_reverse_odex() {
	echo
	echo "PHASE : Odex2dex"
	echo
	if [ ! -r "$1" ]; then
		echo "$1 not found."
		return 1
	fi

	rm -rf out
	rm classes.dex

	"$BAKSMALITOOL" -d "$SYS_ODEX_DIR" -x "$1"
	if [ $? != 0 ]; then
		echo "Baksmali FAILED."
		echo "Decompile code FAILED"
		return 1
	fi

	"$SMALITOOL" out -o classes.dex
	if [ $? != 0 ]; then
		echo "Smali FAILED."
		echo "Decompile code FAILED"
		return 1;
	fi

	local tmpfile=`pwd`/classes.dex
	yaad_dex2code "$tmpfile"
	local ret=$?

	rm -rf out
	rm classes.dex
	return "$ret";
}

yaad_reverse_jar() {
	if [ ! -e "$FILENAME" ]; then
		# Whatever create direcotry
		mkdir "$FILENAME"
	fi

	echo
	echo "PHASE : Decompile code"
	echo

	# local oldPos=`pwd`
	cd "$FILENAME"
	
	# Decompile code 
	unzip -q -o "$FILEPATH" classes.dex

	if [ $? = 0 ]; then
		local pDexFile=`pwd`/classes.dex
		yaad_dex2code "$pDexFile"
		local ret=$?
		rm classes.dex
		return "$ret"
	fi

	return 1
}

SYS_ODEX_DIR="${progdir}/system"
# SCRIPTNAME="${0##*/}"

TEMP=`getopt -o s:h --long help,system: -n "${0##*/}" -- "$@"`

if [ $? != 0 ] ; then 
#	echo "Error" >&2
	exit 1  
fi

# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

while true ; do
	case "$1" in
		-h|--help) yaad_usage ; exit 0 ;;

		-s|--system) 
			if [ -d "$2" -a -r "$2" ]; then
				# Use absolute path
				oldwd=`pwd`
				cd "$2"
				SYS_ODEX_DIR=`pwd`
				cd "$oldwd"
			else
				SYS_ODEX_DIR=
			fi
			shift 2 ;;

		--) shift ; break ;;

		*) echo "Error: $1 is invalid argument!" ; exit 1 ;;
	esac
done

if [ ! -r "$1" ]; then
	echo "Error: no valid file to decompile."
	exit 1
fi

# Use absolute path
FULLNAME="${1##*/}"
oldwd=`pwd`
cd `dirname "$1"`
export FILEPATH=`pwd`/"$FULLNAME"
export FILENAME="${FULLNAME%.*}"
export SYS_ODEX_DIR
cd "$oldwd"

# Whether it is formed in xx.apk/odex
if expr "$FULLNAME" : '.*\.\([aA][pP][kK]\)$' > /dev/null; then
	yaad_reverse_apk 
elif expr "$FULLNAME" : '.*\.\([jJ][aA][rR]\)$' > /dev/null; then
	yaad_reverse_jar 
elif expr "$FULLNAME" : '.*\.\([oO][dD][eE][xX]\)$' > /dev/null; then
	if [ ! -e "$FILENAME" ]; then
		mkdir "$FILENAME"
	fi
	cd "$FILENAME"
	yaad_reverse_odex "$FILEPATH"
else
	echo "The decompiled file is not supported."
	exit 1
fi
res=$?
echo 
echo "Finished"
echo
exit "$res"