pkg repacking/unpacking minor changes

fw_updater_packer_unpacker/README.md

@@ -0,0 +1,27 @@
+# Official Version
+
+Only support unpacking since we don't have the encryption key to repack it.
+
+Usage:
+```
+chmod +x official_pkg_unpacker_pkg.sh
+./official_pkg_unpacker_pkg.sh <file/path/to/official/pkg> <output/folder/path>
+```
+
+# Unofficial Version
+
+With modified diagnosis mode, it shall support unofficial pkg.
+
+Unpacker is the same as official one, except we disabled verification.
+
+The repacker follows a reversed procedure, but we simply use the data encryption key.
+
+Usage:
+```
+chmod +x unofficial_pkg_unpacker_pkg.sh
+chmod +x unofficial_pkg_repacker_pkg.sh
+
+
+./unofficial_pkg_unpacker_pkg.sh <file/path/to/official/pkg> <output/folder/path>
+./unofficial_pkg_repacker_pkg.sh <previous/output/folder/path>
+```

fw_updater_packer_unpacker/unofficial_pkg_repacker.sh

@@ -37,7 +37,7 @@ INDIR=$1  # input folder
 TMPDIR=$INDIR
 PKGFILE=$1/repacked.pkg  # output pkg file
 SHA256KEY="./key.pub"
-SIGKEY="./key.private_sig"  # unfortunately we do not have this
+SIGKEY="./key.private"  # we use data encryption key (ignored anyway)
 DATAKEY_D="./key.private"
 
 
@@ -76,10 +76,10 @@ 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
+# 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"

fw_updater_packer_unpacker/unofficial_pkg_unpacker.sh

@@ -0,0 +1,125 @@
+#!/bin/sh
+
+# Unpacker 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
+# |- ...
+
+
+# params
+PKGFILE=$1  # pkg file
+OUTDIR=$2  # output folder
+SHA256KEY="./key.pub"
+DATAKEY_D="./key.private"
+
+# predefined outputs
+SIGFILE="$OUTDIR/signature"
+AESFILE="$OUTDIR/aes.key"
+IVFILE="$OUTDIR/init_vector"
+SIGFILE_ANIM="$OUTDIR/signature_animation"
+
+# commands
+ODUMP="od -A n -t d4 -v"
+
+
+# check if output folder does not exist, make one
+if [[ ! -d $OUTDIR ]]; then
+  mkdir $OUTDIR;
+fi
+if [[ ! -d $OUTDIR ]]; then  # check again
+  echo "! Err: looks like we cannot create this folder"
+  exit 0
+fi
+
+echo "* file header check.."
+if [ $(head -c 4 $PKGFILE) != "DPUP" ]; then
+  echo "! Err: this seems to be an invalid pkg"
+  exit 0
+fi
+
+echo "* getting data block size"
+OFFSET_DATA=`dd if=$PKGFILE bs=4 skip=1 count=1 2>/dev/null | $ODUMP`
+DATA_SIZE=`dd if=$PKGFILE bs=4 skip=2 count=1 2>/dev/null | $ODUMP`
+
+echo "* extract signature.."
+SIG_SIZE=`dd if=$PKGFILE bs=4 skip=4 count=1 2>/dev/null | $ODUMP`
+dd if=$PKGFILE of=$SIGFILE bs=1 skip=20 count=$((SIG_SIZE)) 2>/dev/null
+
+echo "* verify data with signature.."
+dd if=$PKGFILE bs=$((OFFSET_DATA)) skip=1 2>/dev/null | head -c $((DATA_SIZE)) | openssl dgst -sha256 -verify $SHA256KEY -signature $SIGFILE 1>/dev/null
+# if [ $? -ne 0 ]; then
+#   echo "! Err: failed to verify data with provided signature"
+#   exit 0
+# fi
+
+echo "* get encrypted data aes key.."
+OFFSET_DATAKEY_E=$((20 + SIG_SIZE + ((-(SIG_SIZE % 16)) % 16)))
+DATAKEY_E_SIZE=`dd if=$PKGFILE bs=1 skip=$OFFSET_DATAKEY_E count=4 2>/dev/null | $ODUMP`
+OFFSET_DATAKEY_E=$((OFFSET_DATAKEY_E + 4))
+echo "** decrypt it via $DATAKEY_D"
+dd if=$PKGFILE bs=1 skip=$OFFSET_DATAKEY_E count=$((DATAKEY_E_SIZE)) 2>/dev/null | openssl rsautl -decrypt -inkey $DATAKEY_D > $AESFILE
+
+echo "* extract 32-byte initial vector.."
+OFFSET_IV=$((OFFSET_DATAKEY_E + DATAKEY_E_SIZE))
+dd if=$PKGFILE of=$IVFILE bs=1 skip=$OFFSET_IV count=32 2>/dev/null
+
+echo "* decrypt data to zipped tar.."
+dd if=$PKGFILE bs=$((OFFSET_DATA)) skip=1 2>/dev/null | head -c $((DATA_SIZE)) | openssl enc -d -aes-256-cbc -K `cat $AESFILE` -iv `cat $IVFILE` > $OUTDIR/decrypted_pkg.tar.gz
+
+echo "* unzip data.."
+tar -xzf $OUTDIR/decrypted_pkg.tar.gz -C $OUTDIR
+
+echo "* checking if animation data followed by.."
+OFFSET_ANIM_HEADER=$((OFFSET_DATA + DATA_SIZE))
+ANIM_HEADER_SIZE=`dd if=$PKGFILE bs=1 skip=$OFFSET_ANIM_HEADER count=4 2>/dev/null | $ODUMP`
+if [ -z "$ANIM_HEADER_SIZE" ]; then
+  ANIM_HEADER_SIZE=0
+fi
+if [[ $((ANIM_HEADER_SIZE)) -gt 0 ]]; then
+  echo "** found animation block, getting animation data size.."
+  ANIM_DATA_SIZE=`dd if=$PKGFILE bs=1 skip=$((OFFSET_ANIM_HEADER + 4)) count=4 2>/dev/null | $ODUMP`
+
+  echo "** get animation signature.."
+  ANIM_SIG_SIZE=`dd if=$PKGFILE bs=1 skip=$((OFFSET_ANIM_HEADER + 8)) count=4 2>/dev/null | $ODUMP`
+  dd if=$PKGFILE of=$SIGFILE_ANIM bs=1 skip=$((OFFSET_ANIM_HEADER + 12)) count=$(($ANIM_SIG_SIZE)) 2>/dev/null
+
+  echo "** verify animation data with signature.."
+  OFFSET_ANIM_DATA=$((OFFSET_ANIM_HEADER + ANIM_HEADER_SIZE))
+  dd if=$PKGFILE bs=$((OFFSET_ANIM_DATA)) skip=1 2>/dev/null | head -c $((ANIM_DATA_SIZE)) | openssl dgst -sha256 -verify $SHA256KEY -signature $SIGFILE_ANIM
+  if [ $? -ne 0 ]; then
+    echo "! Err: failed to verify animation data with provided signature"
+    exit 0
+  fi
+
+  echo "** dump animation data to zipped tar.."
+  dd if=$PKGFILE bs=$((OFFSET_ANIM_DATA)) skip=1 2>/dev/null > $OUTDIR/decrypted_animation_pkg.tar.gz
+
+  echo "** unzip the tar.."
+  tar -xzf $OUTDIR/decrypted_animation_pkg.tar.gz -C $OUTDIR
+fi
+