From 0b1149518d46d294690142bbe29e1adeec5ab89b Mon Sep 17 00:00:00 2001
From: Alessandro Mauri <alemauri001@gmail.com>
Date: Sat, 22 Aug 2020 13:35:31 +0200
Subject: [PATCH] more complete version of the prepare script

- dependencies are fetched recursively
- script is more verbose
- increased compression ratio of package
- strip preload of comments before injection
- more I am missing
---
 .gitignore    |  1 +
 posix/preload |  4 ++--
 posix/prepare | 61 ++++++++++++++++++++++++++++++++++-----------------
 3 files changed, 44 insertions(+), 22 deletions(-)

diff --git a/.gitignore b/.gitignore
index f531ce5..7039b0b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 **/pcmi/**
+**/badwolf/**
diff --git a/posix/preload b/posix/preload
index e08451c..a07bd1c 100755
--- a/posix/preload
+++ b/posix/preload
@@ -1,7 +1,7 @@
 #!/bin/sh -e
 
+# TODO: verify checksum before extracting
 # SUM
-
 # TODO: extract self without resolving to $0 because it doesn't resolve links
 tail -c +"$(expr BYTES + 1)" $0 | lz4 -dc | tar -x
 # TODO: remove hardcoded directory
@@ -12,7 +12,7 @@ export ORIGIN="$(pwd)"
 export LD_LIBRARY_PATH="$ORIGIN/lib"
 export PATH="$ORIGIN/bin":$PATH
 
-export LD_DEBUG='libs'
+#export LD_DEBUG='libs'
 
 # TODO: use $0 instead
 # FIXME: uses the system's basename
diff --git a/posix/prepare b/posix/prepare
index d142f59..13f54b5 100755
--- a/posix/prepare
+++ b/posix/prepare
@@ -1,4 +1,4 @@
-#!/bin/sh -ex
+#!/bin/sh -e
 
 # NEEDED: lz4 readelf tar cat awk cut sed sh sort
 
@@ -20,22 +20,38 @@ getlibs ()
 	tmplist=$WORKDIR/tmplist
 
 	touch $LIBLIST
-	
+
+	# Take the executable and get the first level dependencies
 	readelf -d "$1" |
 	grep NEEDED |
 	awk '{print $5}' |
 	sed s/\\[/\ / | sed s/\\]/\ / > $tmplist
 
-	while test -s $tmplist; do
+	# While there are more dependencies
+	while [ "$(cat $tmplist)" ]; do
+		# Add them to the master file
 		cat $LIBLIST $tmplist > $tmpfile
 		mv -f $tmpfile $LIBLIST
-		for f in $tmplist; do
-			readelf -d "$f" |
-			grep NEEDED |
-			awk '{print $5}' |
-			sed s/\\[/\ / | sed s/\\]/\ / > $tmplist
+
+		# Copy them to lib/
+		while read l; do
+			find -L $SYS_LIBDIR -maxdepth 2 -name "$l" -exec cp -n {} $WORKDIR/lib/ \;
+		done < $tmplist
+
+		# Extract their dependencies
+		touch $tmpfile
+		for f in $WORKDIR/lib/*; do
+			if [ "$(grep -F "$(basename "$f")" "$tmplist")" ]; then
+				readelf -d "$f" |
+				grep NEEDED |
+				awk '{print $5}' |
+				sed s/\\[/\ / | sed s/\\]/\ / >> $tmpfile
+			fi
 		done
+		sort -u $tmpfile > $tmplist
 	done
+	sort -u $LIBLIST > $tmpfile
+	mv -f $tmpfile $LIBLIST
 	rm -f $tmplist
 }
 
@@ -76,22 +92,25 @@ mkdir -p $WORKDIR/ext
 touch $WORKDIR/env
 
 # TODO: add usage and error checking
-# FIXME: double sed should be avoided
 DIRNAME="$WORKDIR"/"$(head -1 $WORKDIR/id | awk '{print $1}')"
 
 if test -s $LIBLIST; then
 	rm -f $LIBLIST
 fi
 
+echo "Fetching dependencies and stripping binaries..."
+# TODO: get al binary dependencies from deps file
+# Get all dependencies and strip them
 for b in $WORKDIR/bin/*; do
 	getlibs $b
+	strip $b
+done
+echo "Stripping libraries..."
+for l in $WORKDIR/lib/*; do
+	strip $l
 done
-sort -u $LIBLIST > $tmpfile
-mv -f $tmpfile $LIBLIST
-while read f; do
-	find -L $SYS_LIBDIR -maxdepth 2 -name "$f" -exec cp -n {} $WORKDIR/lib/ \;
-done < $LIBLIST
 
+echo "Compressing destination directory..."
 if test -d $DIRNAME; then
 	rm -rf $DIRNAME
 fi
@@ -106,11 +125,13 @@ cp $WORKDIR/id $DIRNAME/
 
 tar -c -f $DIRNAME.tar -C $WORKDIR "$(basename $DIRNAME)"
 md5sum -b $DIRNAME.tar | cut -d " " -f1 > $SUMFILE
-lz4 --rm $DIRNAME.tar
+lz4 --rm -9 -c $DIRNAME.tar > "$DIRNAME".tar.lz4
 
+echo "Injecting payload..."
 cat "$PRELOAD_SCRIPT" |
 sed s/SUM/"$(cat $SUMFILE)"/ |
-sed s/ID/"$(basename "$DIRNAME")"/ > tpp
+sed s/ID/"$(basename "$DIRNAME")"/ |
+awk '!/^ *#/ && NF' > tpp
 
 size="$(wc -c tpp | cut -d " " -f1)"
 strsize="$(echo "BYTES" | wc -c)"
@@ -119,10 +140,10 @@ normsize="$(expr "$size" - "$(expr "$strsize" - "$numsize")")"
 
 cat tpp |
 sed s/BYTES/"$normsize"/ > tpr
-cat tpr "$DIRNAME".tar.lz4 > "$DIRNAME".it
+cat tpr "$DIRNAME".tar.lz4 > "$DIRNAME".ti
 
+echo "Cleaning up..."
 rm -f tpr tpp
-chmod +x "$DIRNAME".it
+chmod +x "$DIRNAME".ti
 
-rm -rf "$DIRNAME" 
-#"$DIRNAME".tar*
+rm -rf "$DIRNAME" "$DIRNAME".tar*