isolatedM

#!/bin/bash
#: Title		: isolatedM
#: Date			: 2017-11-8
#: Author		: "Andreas O. Bender" <andreasobender@mac.com>
#: Version		: 0.2
#: Description		: control symmetric encryption and authentication on an isolated computer
#: Options		: None
#: Required files	: firstPart.ps, secondPart.ps, messageCounter, keyChoiceAuth
#: Required programs	: QR Journal, gpg, openssl


. ./functionsIsolated


# user has options (1 encrypt) or (2 decrypt) until program is terminated by option (3 quit)

while :
do

printf "\n%s\n"  "1 encrypt"
printf "%s\n"    "2 decrypt"
printf "%s\n\n"  "3 quit"

# read in number of chosen option 1, 2 or 3
read -p "enter option number: " choice

case $choice in
1)
  # user chooses file of plaintext to encrypt
  chooseFile

  # test whether chosen file exists
  if [ -f $chosenFile ]
  then
    # display file chosen for encryption and ask user for permission to authenticate
    cat $chosenFile
    printf "\n"
    read -p "do you want to authenticate this plaintext? - y/n: " permissionAuth

    if [ $permissionAuth = y ] 
    then
      # add message counter and timestamp to plaintext file
      counterTimestamp

      # authenticate file
      inputfile=$chosenFile$fileDate
      authenticateFile

      # encrypt file
      encryptFile

      # encode file as QR code
      fileToEncode=$inputfile.asc
      encodeFile

      # check for creation of QR code
      if [ -f $fileToEncode.ps ]
      then
        # move QR code to directory QRsent
        mv -i $fileToEncode.ps QRsent

        # display QR code on screen
        open QRsent/$fileToEncode.ps
      fi

      # move ciphertext to directory cipherTextSent
      mv -i $inputfile.asc cipherTextSent

    else
      printf "%s\n" "authentication refused, no action taken"
    fi
  else 
    printf "\n%s\n\n" "file does not exist"
  fi
  ;;


2)
  # scan in QR code
  scanQRcode

  startString='\-\-\-\-\-BEGIN PGP MESSAGE-----'
  endString='\-\-\-\-\-END PGP MESSAGE-----'
 
  # check scanned file for presence of startString and endString
  if [ $(grep -c "$startString" "$qrScanData") -eq 1 ] && [ $(grep -c "$endString" "$qrScanData") -eq 1 ]
  then
    # strip xml formatting off scanned file
    stripFile

    # decrypt $scannedFile.asc
    decryptFile

    # check authentication of plaintext
    checkAuthentication
    if [ $? = 0 ]
    then
      printf "\n%s\n" "$scannedFile successfully authenticated"

      # remove files containing new and included hmac
      srm -m newAuthFile
      srm -m includedAuthFile

      # extract second line containing timestamp
      sed "1q;d" $scannedFile > timestamp
      
      # check second line for correctly formatted timestamp
      if [ $(egrep -c '\-'[0-9][0-9]'Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec'[0-3][0-9]'\-'[0-2][0-9].[0-5][0-9].[0-5][0-9] timestamp) -eq 1 ]
      then 
        timestampProcess
      else
        noTimestampProcess
      fi    

      # erase auxiliary files
      srm -m timestamp
    else
      printf "\n%s\n" "authentication failed"

      # remove files containing hmac and plaintext
      srm -m $scannedFile
      srm -m newAuthFile
      srm -m includedAuthFile

    fi

  else

    printf "\n%s\n" "file is not formatted as PGP ciphertext"

    # erase scanned image and text file containing scanned text
    olddir=$(pwd)
    cd "$HOME/Library/Containers/com.joshjacob.qrjournal/Data/Library/Application Support/QRJournal"
    rm *.jpg
    rm QRJournal.storedata
    cd $olddir

  fi 
  ;;


3)
  # quit program
  printf "\n%s\n" "bye"
  exit 0
  ;;
esac

done