1 files changed, 75 insertions(+), 0 deletions(-)

A partial_enc/simulacro_2.sh

@@ 0,0 1,75 @@
+#!/bin/bash
+
+#position in where to change the contents
+pos=$1
+
+#binary file
+bfile=$2
+
+# saving the hex info in a tmp file to manipulate the contents
+xxd $bfile > tmp
+
+# read the desired line and save it
+line=$(head -n $pos tmp | tail -1)
+#echo "$line"
+
+rm tmp
+
+#keeping only the hex value
+tmp_hex=${line#*:}
+tmp_hex=${tmp_hex:0:40}
+
+#echo "DEBUG $tmp_hex"
+
+#encrypting
+echo "$tmp_hex" | xxd -r -p | openssl enc -e -base64 -aes-128-ctr -nopad -nosalt -k test > tmp 
+
+#echo "#################"
+
+#cleaning so to leave the warnings aside and keeping the content of the encryption
+
+#strings tmp | tail -1
+
+enc_hex=$(strings tmp | tail -1)
+rm tmp
+
+#echo "DEBUG $final"
+
+# encrypted to hex
+
+# string to hex
+enc_s2=$(echo $enc_hex | od -A n -t x1)
+#formatting
+# delete spaces
+enc_s2=${enc_s2//" "}
+
+# add spaces aech 4 characters
+count=0
+nstr=""
+
+for i in $(seq 1 ${#enc_s2})
+do 
+        if [ $count -eq 4 ]; then 
+                nstr="${nstr} "
+                count=0; 
+        else 
+                nstr="${nstr}${enc_s2:i-1:1}" 
+                count=$(($count + 1))
+        fi 
+done
+
+#injecting 
+
+# position where to inject
+npos=$(($pos*32))
+
+echo -e "the position where to inject the encrypted: $nstr is\n $npos"
+
+read -p"continue? Y/N " DUMMY
+
+dd conv=notrunc obs=1 if=<(xxd -r -p -o 1 -s +$npos <(echo $nstr)) of=$bfile
+
+echo "Done!"
+
+
+