bofcrypt.sh

#!/bin/bash

PUBLICKEY=$1
INPUTFILE=$2

#generate session key that is used to encrypt the file
#256 bits = 32 bytes = 64 characters in hex
SESSIONKEY=$(openssl rand -hex 32)
#use dummy sessionkey for debugging purposes
#SESSIONKEY="0000000000000000000000000000000000000000000000000000000000000000"

#initialization vector 16 bytes = 32 characters in hex
IV=$(openssl rand -hex 16)
#use dummy initializationvector for debugging purposes
#IV="00000000000000000000000000000000"

#encrypt the file using the generated session key
#key and iv need to be in hex format 
#also add the raw initialization vector in front
echo "${IV}" | xxd -r -p > OUT_BUFFER_RAW
openssl enc -aes-256-cbc -K "${SESSIONKEY}" -iv "${IV}" -in "${INPUTFILE}" >> OUT_BUFFER_RAW
#  use -nosalt for debugging purposes
#openssl enc -aes-256-cbc -nosalt -K $SESSIONKEY -iv $IV -in $INPUTFILE >> OUT_BUFFER_RAW

base64 --wrap=0 OUT_BUFFER_RAW > OUT_BUFFER

#encrypt the raw session key using the recipients public key
echo "${SESSIONKEY}" | xxd -r -p | openssl rsautl -encrypt -inkey "${PUBLICKEY}" -pubin > SESSION_KEY_RAW
base64 --wrap=0 SESSION_KEY_RAW > SESSION_KEY

#output to xml with binary values base64 encoded
cat  << EOF
<?xml version="1.0" encoding="utf-8"?>
<ENCRYPTED_REPORT xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <TITLE>BOFCRYPTNXT</TITLE>
  <VERSION>2.0</VERSION>
  <SESSION_KEY>$(<SESSION_KEY)</SESSION_KEY>
  <OUT_BUFFER>$(<OUT_BUFFER)</OUT_BUFFER>
</ENCRYPTED_REPORT>
<!-- https://github.com/dgm9704/bofcrypt -->
EOF