EncryptEverything

What is it?

This is a Chrome extenxion implementing PGP style encryption capabilities. It can be used to encrypt text in any web-based medium and decrypt the result.

Who made it?

This project was a collaboration by Patrick Whitsell ([email protected]), Casey McGinley ([email protected]), and Fernando Maymi ([email protected]). The extension was made as part of their Applied Cryptography (CS-GY 6903) class taught by Prof. Giovanni Di Crescenzo

What external libraries/sources does it use?

• Stanford Javascript Crypto Library (sjcl)
  • used for symmetric encryption of payloads (AES-256 CCM), hashing (SHA256), encoding (hex, base64, etc.) and a few other things
  • https://github.com/bitwiseshiftleft/sjcl
  • Configured with:

./configure --without-all --with-aes --with-ctr --with-sha256 --with-random --with-hmac --with-codecBase64 --with-codecHex --with-bitArray --with-convenience

• JSEncrypt
  • used for asymmetric encryption for the purposes of key exchange and digital signatures (RSA 2048-bit keys)
  • we modified this slightly to allow us to encrypt with a private key
  • https://github.com/travist/jsencrypt
• SweetAlert
  • used for aesthetics
  • https://t4t5.github.io/sweetalert/

How do I load it into Chrome?

• Clone this repo
• Open Chrome
• Go to: Settings --> Extensions
• Make sure the "Developer Mode" box is checked
• Click "Load unpacked extension..."
• Select your local copy of the EncryptEverything repo

But how do I use it?

• First, you'll need a pair of public and private RSA keys, 2048-bit in standard RSA PEM format
  • The best way to do this is with ssh-keygen, standard in most bash environments and availble in Git Bash on Windows
  • First, generate your key pair (see first code block below)
  • When complete, you will get two files, id_rsa and id_rsa.pub
  • id_rsa is your private key and it is already in the correct format
  • id_rsa.pub needs to be converted to PEM format (see 2nd code block below)
  • Alternatively, if you are just looking to test this out and don't care where the keys come from, you can use this online RSA key generator from JSEncrypt
  • http://travistidwell.com/jsencrypt/demo/index.html

Generate keys:

ssh-keygen -t rsa -b 2048

Convert .pub to .pem:

ssh-keygen -f id_rsa.pub -e -m pem > id_rsa.pem

• Now that you have your keys, click the extenstion and hit "Manage"
• Here, you can copy and paste your private key, as well as some identifier for yourself (email works well)
• You will also provide a password when entering your private key, don't forget it
• Now you must enter the public keys
  • If you just wish to test this out on your own keyset, then just add your public key here with the same identifier you used for your private key
  • Otherwise, you must find some friends and get their public keys :)
• Once all the keys are imported, hit "Close"
• You are ready to encrypt!
  • Highlight the text you want to encrypt
  • Open the extension and hit "Encrypt"
  • Select the person you are sending this message to
  • Press "Select"
  • Enter your password to decrypt the private key from storage
  • If successful, the encrypted text is copied to your clipboard and you can paste it where you will
• You can also decrypt if you have some encrypted payload
  • Highlight the encrypted text
  • Press "Decrypt"
  • Provide your password to decrypt your private key
  • If successful, your plaintext message is revealed; pressing "Copy" will add it to your clipboard
• Some final thoughts
  • You will not be able to decrypt the same encrypted payload twice due to our attempts to thwart replay attacks
  • Don't forget your password for your private key; if you do you'll need to enter the private key again
  • If you want to send messages to others you will need to exchange public keys first (we don't provide an infrastructure to do this for you)

What cryptographic primitives/methods does it make use of?

• Asymmetric encryption
  • RSA-2048
  • Confidentiality, key exchange
• Symmetric encryption
  • AES-256 CCM mode (CTR + CBC-MAC)
  • Confidentiality
• Hash
  • SHA256
  • Integrity
• Digital signature
  • SHA256 hash encrypted by 2048-bit RSA private key
  • Integrity, authenticity
• Nonce
  • Timestamp (in milliseconds)
  • Replay detection

What security concerns does it satisfy?

• Confidentiality
• Integrity
• Authenticty
• Replay detection