From 060a747d622a587c507a2a98cbfc381701d431e1 Mon Sep 17 00:00:00 2001
From: HappyZ <zhuyanzi@gmail.com>
Date: Sun, 19 Aug 2018 01:07:57 -0700
Subject: [PATCH] add bash to pack pkg - missing private key

---
 fw_updater_packer_unpacker/repacker_pkg.sh | 102 +++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100755 fw_updater_packer_unpacker/repacker_pkg.sh

diff --git a/fw_updater_packer_unpacker/repacker_pkg.sh b/fw_updater_packer_unpacker/repacker_pkg.sh
new file mode 100755
index 0000000..9548c9a
--- /dev/null
+++ b/fw_updater_packer_unpacker/repacker_pkg.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+
+# Repacker for DPT pkg
+# HappyZ
+# Thanks to anonymous contributer somewhere on earth
+
+# PKG FILE FORMAT
+# byte 1--4:          DPUP - file recognizer
+# byte 5--8:          data offset location A
+# byte 9--12:         total data content size D
+# byte 13--16:        nothing
+# byte 17--20:        sigfile size B
+# byte 21--(20+B):    sigfile data
+# byte (21+(-B%16)%16)--(25+(-B%16)%16):  encrypted data aes key size (BE) C
+# byte (+1)--(+C):    encrypted data aes key bytes
+# byte (+1)--(+32):   initial vector  --- up till now bytes shall equal to A
+# byte (A+1)--(A+D):  encrypted data
+# byte (+1)--(+4):    animation header size E
+# byte (+1)--(+4):    animation data size F
+# byte (+1)--(+4):    animation sigfile size G
+# byte (+1)--(+(-G%16)%16): animation sigfile --- here bytes shall be A+D+E
+# byte (A+D+E+1)--(A+D+E+F): animation data
+
+# zipped data format
+# FwUpdater
+# |- boot.img
+# |- boot.img.md5
+# |- system.img
+# |- system.img.md5
+# |- eufwupdater.sh
+# |- ...
+
+# we do not care about animation
+
+# params
+INDIR=$1  # inputer folder
+TMPDIR=$INDIR
+PKGFILE=$1/repacked.pkg  # output pkg file
+SHA256KEY="./key.pub"
+SIGKEY="./key.private_sig"  # unfortunately we do not have this
+DATAKEY_D="./key.private"
+
+
+
+# predefined outputs
+SIGFILE="$INDIR/signature"
+AESFILE="$INDIR/aes.key"
+IVFILE="$INDIR/init_vector"
+SIGFILE_ANIM="$INDIR/signature_animation"
+
+# check if input folder exists
+if [[ ! -d $INDIR ]]; then
+  echo "! Err: input folder does not exist"
+  exit 0
+fi
+
+echo "* zip data.."
+cd $INDIR && tar -czf repacked_pkg.tar.gz FwUpdater/ && cd ..
+
+echo "* encrypt zipped tar"
+openssl enc -e -aes-256-cbc -K `cat $AESFILE` -iv `cat $IVFILE` -in $INDIR/repacked_pkg.tar.gz -out $TMPDIR/tmp.step1
+OFFSET_DATA=0
+DATA_SIZE=$(wc -c < $TMPDIR/tmp.step1)
+
+echo "* add 32-byte initial vector"
+cat $IVFILE $TMPDIR/tmp.step1 > $TMPDIR/tmp.step2
+OFFSET_DATA=$((OFFSET_DATA + 32))
+
+echo "* encrypt the aes key with our private $DATAKEY_D"
+openssl rsautl -encrypt -inkey $DATAKEY_D -in $AESFILE -out $TMPDIR/tmp.step3.1
+DATAKEY_E_SIZE=$(wc -c < $TMPDIR/tmp.step3.1)
+cat $TMPDIR/tmp.step3.1 $TMPDIR/tmp.step2 > $TMPDIR/tmp.step3.2
+printf "%.8x" $((DATAKEY_E_SIZE)) | sed -E 's/(..)(..)(..)(..)/\4\3\2\1/' | xxd -r -p | cat - $TMPDIR/tmp.step3.2 > $TMPDIR/tmp.step3
+OFFSET_DATA=$((OFFSET_DATA + DATAKEY_E_SIZE + 4))
+
+echo "* sign w/ private key $SIGKEY"
+openssl dgst -sha256 -sign $SIGKEY -out $TMPDIR/tmp.step4.1 $TMPDIR/tmp.step1
+openssl dgst -sha256 -verify $SHA256KEY -signature $TMPDIR/tmp.step4.1 $TMPDIR/tmp.step1
+if [ $? -ne 0 ]; then
+  echo "! Err: failed to verify sha256 - highly likely $SIGKEY is wrong"
+  exit 0
+fi
+SIG_SIZE=$(wc -c < $TMPDIR/tmp.step4.1)
+if [ $(((-(SIG_SIZE % 16)) % 16)) -gt 0 ]; then
+  echo "! Err: not supported for SIG_SIZE not mutiple of 16"
+  exit -1
+fi
+cat $TMPDIR/tmp.step4.1 $TMPDIR/tmp.step3 > $TMPDIR/tmp.step4.2
+printf "%.8x" $((SIG_SIZE)) | sed -E 's/(..)(..)(..)(..)/\4\3\2\1/' | xxd -r -p | cat - $TMPDIR/tmp.step4.2 > $TMPDIR/tmp.step4
+OFFSET_DATA=$((OFFSET_DATA + SIG_SIZE + 4))
+
+echo "* assign data block size and offset"
+printf "%.8x" 0 | sed -E 's/(..)(..)(..)(..)/\4\3\2\1/' | xxd -r -p | cat - $TMPDIR/tmp.step4 > $TMPDIR/tmp.step5.1
+printf "%.8x" $((DATA_SIZE)) | sed -E 's/(..)(..)(..)(..)/\4\3\2\1/' | xxd -r -p | cat - $TMPDIR/tmp.step5.1 > $TMPDIR/tmp.step5.2
+OFFSET_DATA=$((OFFSET_DATA + 4 + 4 + 4 + 4))
+
+echo "OFFSET_DATA: $OFFSET_DATA, DATA_SIZE: $DATA_SIZE"
+
+printf "%.8x" $((OFFSET_DATA)) | sed -E 's/(..)(..)(..)(..)/\4\3\2\1/' | xxd -r -p | cat - $TMPDIR/tmp.step5.2 > $TMPDIR/tmp.step5
+
+echo "* add file header"
+printf "DPUP" | cat - $TMPDIR/tmp.step5 > $PKGFILE