Data.QRCodes

Module providing several functions for creating QR codes and their signed counterparts

Functions on objects

createQRCode :: ToJSON a => a -> FilePath -> IO ()

Creates a QR code from an object that is part of the ToJSON class

createQRCode userRecord "user-231.png"

createSecureQRCode :: ToJSON a => a -> FilePath -> FilePath -> IO ()

Creates a signed QR code from an object that is part of the ToJSON class

createSecureQRCode' :: ToJSON a => a -> (PublicKey, PrivateKey) -> FilePath -> IO ()

Creates a signed QR code from an object that is part of the ToJSON class

Functions for ByteStrings

byteStringToQR :: ByteString -> FilePath -> IO ()

Creates a QR code from a strict bytestring

byteStringToQRSec :: ByteString -> FilePath -> FilePath -> IO ()

Creates a signed QR code from a strict bytestring and path to keyfile/path. If the keyfile does not already exist it will be generated, otherwise it will be read.

Note that QR codes may only contain a small number of characters, so encrypting can sometimes make an object too big to encode.

byteStringToQRSec (BS.pack "hello") ".key.hk" "qrcode.png"

byteStringToQRSec' :: ByteString -> (PublicKey, PrivateKey) -> FilePath -> IO ()

Create a signed QR code from a strict ByteString and a key

byteStringToQRSec' (BS.pack "Vanessa") (generate 256 0x10001)

functions to read QR codes

readQRString :: FilePath -> IO String

given a filepath, read the QR code as a string in all lowercase

readQRString "picture.jpg"

readQRStrSec :: FilePath -> FilePath -> IO String

given a filepath pointing to a QR code, get the contents & verify signature with the keyfile

readQRStrSec "output.png" ".key.hk"

readQRStrSec' :: FilePath -> (PublicKey, PrivateKey) -> IO String

Read an image containing a QR code, decode and verify the signature using the given key.