picsoritdidnthappen

#!/bin/bash
# -----------------------------------------------------------
# script that generates and encrypts/compresses random files
# then stores encrypted file in image and audio files using 
# steghide. file is encrypted with long, random, password; 
# but embedded into host file protected by dictionary word.
# easy to extract, hard to crack, all for nothing (random).
# *note*: point $wordlist at a dictionary file or whatever
#
# usage: picsoritdidnthappen ~/pictures/Lulz
# -----------------------------------------------------------

wordlist="/usr/share/dict/american-english-insane"

# -----------------------------------------------------------
# select a random word from $wordlist to use as passphrase
# for encrypting embedded file into cover file
# -----------------------------------------------------------
pass_pls () {
    num_words=$(wc -l "${wordlist}" | cut -d ' ' -f 1)
    guest_word=$(($RANDOM % $num_words))
    guest_pass=$(sed -n "${guest_word} p" "${wordlist}")
    echo "${guest_pass/\'/}"
}


do_a_stego () {
    # -----------------------------------------------------------
    # set guest file to same filename as host file sans extension
    # if no extension in host file, append underscore to guest
    # -----------------------------------------------------------
    hostfile="${1}"
    guestfile="${hostfile%.*}"
    if [[ ${hostfile} == ${guestfile} ]]; then
        guestfile="${guestfile}_"
    fi

    # -----------------------------------------------------------
    # determine file size and generate file
    # -----------------------------------------------------------
    hfilesize=$(stat -c%s "${hostfile}")
    gfilesize=$(($hfilesize / 8))
    gfilesize=$(($RANDOM % $gfilesize))
    ((++filesize))
    dd if=/dev/urandom of="${guestfile}" bs="${filesize}" count=1 status=noxfer conv=noerror,notruc 2> /dev/null

    # -----------------------------------------------------------
    # decide format and compress/encrypt accordingly
    # -----------------------------------------------------------
    random_pass=$(dd if=/dev/urandom bs=128 count=1 status=noxfer 2> /dev/null | sha512sum - | cut -f 1 -d ' ')
    extension=$(($RANDOM % 3))
    case "${extension}" in
        0)
            tempfile="${guestfile}.gpg"
            gpg -q --yes -o "${tempfile}" --passphrase "${random_pass}" -c "${guestfile}" &> /dev/null 
            ;;
        1)
            tempfile="${guestfile}.rar"
            rar a -o+ -hp"${random_pass}" "${tempfile}" "${guestfile}" &> /dev/null 
            ;;
        2)
            tempfile="${guestfile}.7z"
            7za a -y -mhe=on -p"${random_pass}" "${tempfile}" "${guestfile}" &> /dev/null 
            ;;
    esac

    # -----------------------------------------------------------
    # get (dictionary) password and embed encrypted guest file
    # -----------------------------------------------------------
    guest_pass=$(pass_pls)
    steghide embed -ef "${tempfile}" -cf "${hostfile}" -p "${guest_pass}" -z 1 -N -q
    shred -n 1 -zu "${guestfile}" "${tempfile}" 2> /dev/null
}


main () {
    find "${1}" -type f \( -iname "*.bmp" -o -iname "*.jpg" -o -iname "*.wav" -o -iname "*.au" \) | while read filename; do
        do_a_stego "${filename}"
    done
}



# -----------------------------------------------------------
# check for command-line arguments
# -----------------------------------------------------------
if [[ -z "${1}" || -z "${2}" ]]; then
    echo "Usage: $0 <directory> <iterations>"
    exit 9001
fi

main "${1}" 
exit 0