Move help into a function

This commit is contained in:
maride 2022-05-13 23:24:22 +02:00
parent d7a696587b
commit 2413c84586

65
barf.sh
View File

@ -19,6 +19,32 @@ BARFPATH="$(dirname $(realpath $0))/src"
CHUNKSIZE=1
PERSISTENT="False"
# show the help and exit
function show_help {
echo "Usage: ./barf.sh <options ...> ./path/to/your/binary"
echo ""
echo " BASIC OPTIONS"
echo " -p | --positive-addr 0x123456 a location to be counted as good hit"
echo " -n | --negative-addr 0x234567 a location to be counted as bad hit"
echo " -w | --win-addr 0x345678 a location reached if your input is correct"
echo " -l | --lose-addr 0x456789 a location reached if your input is incorrect"
echo ""
echo " PERSISTENT MODE OPTIONS"
echo " -x | --persistent enable the experimental (!) persistent mode"
echo " -s | --start-addr 0x56789A a location directly after your input is fed into the target"
echo " -e | --end-addr 0x6789AB a location where the to-be-fuzzed logic is done"
echo " --buff-addr 0x789ABC the location where user input is stored"
echo ""
echo " MISC OPTIONS"
echo " -b | --prefix CTF{ a known prefix, e.g. the prefix of your flag"
echo " -a | --suffix } a known suffix, e.g. the suffix of your flag"
echo " -c | --chunksize 2 amount of characters to try at once (default: 1)"
echo " -h | --help a great and useful help message, you should try it!"
echo ""
echo "See https://github.com/maride/barf for more information and examples!"
exit 1
}
# getopt is kind-of unstable across distributions and versions, so we implement it on our own
# hat-tip to https://stackoverflow.com/questions/192249/how-do-i-parse-command-line-arguments-in-bash
while [[ $# -gt 0 ]]; do
@ -80,16 +106,22 @@ while [[ $# -gt 0 ]]; do
esac
done
# see if the user needs our help
if [ "$SHOWHELP" == 1 ]; then
show_help
fi
# check if we have all arguments we need
if [ "$POSITIVEADDR" == "" ] && [ "$NEGATIVEADDR" == "" ] || [ "$TARGETFILE" == "" ] ; then
# nope, missing some args
SHOWHELP=1
echo "Missing -p and -n or a target"
show_help
fi
# check if the arguments are valid
if [ ! "$TARGETFILE" == "" ] && [ ! -e "$TARGETFILE" ]; then
echo "The file $TARGETFILE does not exist."
SHOWHELP=1
show_help
fi
# check if the persistent mode can be used
@ -99,34 +131,7 @@ if [[ "$PERSISTENT" == "1" && ("$STARTADDR" == "" || "$ENDADDR" == "" || "$BUFFA
echo "Set --start-addr to an address before your input reaches the program (e.g. before fgets())"
echo "Set --end-addr to an address after the program has checked if the input is good or not (e.g. somewhere after gets('Yay!') and gets('Nay!'))"
echo "Set --buffer-addr to the address where user input is stored (e.g. the address of b in case of fgets(b, 16, stdin)"
SHOWHELP=1
fi
# see if the user needs our help
if [ "$SHOWHELP" == 1 ]; then
echo "Usage: ./barf.sh <options ...> ./path/to/your/binary"
echo ""
echo " BASIC OPTIONS"
echo " -p | --positive-addr 0x123456 a location to be counted as good hit"
echo " -n | --negative-addr 0x234567 a location to be counted as bad hit"
echo " -w | --win-addr 0x345678 a location reached if your input is correct"
echo " -l | --lose-addr 0x456789 a location reached if your input is incorrect"
echo ""
echo " PERSISTENT MODE OPTIONS"
echo " -x | --persistent enable the experimental (!) persistent mode"
echo " -s | --start-addr 0x56789A a location directly after your input is fed into the target"
echo " -e | --end-addr 0x6789AB a location where the to-be-fuzzed logic is done"
echo " --buff-addr 0x789ABC the location where user input is stored"
echo ""
echo " MISC OPTIONS"
echo " -b | --prefix CTF{ a known prefix, e.g. the prefix of your flag"
echo " -a | --suffix } a known suffix, e.g. the suffix of your flag"
echo " -c | --chunksize 2 amount of characters to try at once (default: 1)"
echo " -h | --help a great and useful help message, you should try it!"
echo ""
echo "See https://github.com/maride/barf for more information and examples!"
exit 1
show_help
fi
# ready for take-off