Merge pull request #17 from Zeegomo/port-kedqr

port kedqr to catalyst-toolbox

Cargo.toml

@@ -38,6 +38,11 @@ serde_yaml = "0.8.17"
 sscanf = "0.1"
 thiserror = "1.0"
 url = "2.2"
+hex = "0.4"
+image = "0.23.12"
+qrcode = "0.12"
+quircs = "0.10.0"
+symmetric-cipher = { git = "https://github.com/input-output-hk/chain-wallet-libs.git", branch = "master" }
 
 [dev-dependencies]
 rand_chacha = "0.3"

src/bin/cli/kedqr/mod.rs

@@ -0,0 +1,71 @@
+use catalyst_toolbox::kedqr::{KeyQrCode, QrPin};
+use chain_crypto::bech32::Bech32;
+use chain_crypto::{Ed25519Extended, SecretKey};
+use std::{
+    error::Error,
+    fs::OpenOptions,
+    io::{BufRead, BufReader},
+    path::PathBuf,
+};
+use structopt::StructOpt;
+
+/// QCode CLI toolkit
+#[derive(Debug, PartialEq, StructOpt)]
+#[structopt(rename_all = "kebab-case")]
+pub struct QrCodeCmd {
+    /// Path to file containing ed25519extended bech32 value.
+    #[structopt(short, long, parse(from_os_str))]
+    input: PathBuf,
+    /// Path to file to save qr code output, if not provided console output will be attempted.
+    #[structopt(short, long, parse(from_os_str))]
+    output: Option<PathBuf>,
+    /// Pin code. 4-digit number is used on Catalyst.
+    #[structopt(short, long, parse(try_from_str))]
+    pin: QrPin,
+}
+
+impl QrCodeCmd {
+    pub fn exec(self) -> Result<(), Box<dyn Error>> {
+        let QrCodeCmd { input, output, pin } = self;
+        // open input key and parse it
+        let key_file = OpenOptions::new()
+            .create(false)
+            .read(true)
+            .write(false)
+            .append(false)
+            .open(&input)
+            .expect("Could not open input file.");
+
+        let mut reader = BufReader::new(key_file);
+        let mut key_str = String::new();
+        let _key_len = reader
+            .read_line(&mut key_str)
+            .expect("Could not read input file.");
+        let sk = key_str.trim_end().to_string();
+
+        let secret_key: SecretKey<Ed25519Extended> =
+            SecretKey::try_from_bech32_str(&sk).expect("Malformed secret key.");
+        // use parsed pin from args
+        let pwd = pin.password;
+        // generate qrcode with key and parsed pin
+        let qr = KeyQrCode::generate(secret_key, &pwd);
+        // process output
+        match output {
+            Some(path) => {
+                // save qr code to file, or print to stdout if it fails
+                let img = qr.to_img();
+                if let Err(e) = img.save(path) {
+                    println!("Error: {}", e);
+                    println!();
+                    println!("{}", qr);
+                }
+            }
+            None => {
+                // prints qr code to stdout when no path is specified
+                println!();
+                println!("{}", qr);
+            }
+        }
+        Ok(())
+    }
+}

src/bin/cli/mod.rs

@@ -1,3 +1,4 @@
+mod kedqr;
 mod logs;
 mod notifications;
 mod recovery;
@@ -34,6 +35,8 @@ pub enum CatalystCommand {
     Recover(recovery::Recover),
     /// Download, compare and get stats from sentry and persistent fragment logs
     Logs(logs::Logs),
+    /// Generate qr codes
+    QrCode(kedqr::QrCodeCmd),
 }
 
 impl Cli {
@@ -60,6 +63,7 @@ impl CatalystCommand {
             PushNotification(notifications) => notifications.exec()?,
             Recover(recover) => recover.exec()?,
             Logs(logs) => logs.exec()?,
+            QrCode(kedqr) => kedqr.exec()?,
         };
         Ok(())
     }

src/kedqr/mod.rs

@@ -0,0 +1,206 @@
+use chain_crypto::{Ed25519Extended, SecretKey, SecretKeyError};
+use image::{DynamicImage, ImageBuffer, Luma};
+use qrcode::{
+    render::{svg, unicode},
+    EcLevel, QrCode,
+};
+use std::fmt;
+use std::fs::File;
+use std::io::{self, prelude::*};
+use std::path::Path;
+use std::str::FromStr;
+use symmetric_cipher::{decrypt, encrypt, Error as SymmetricCipherError};
+use thiserror::Error;
+
+pub const PIN_LENGTH: usize = 4;
+
+pub struct KeyQrCode {
+    inner: QrCode,
+}
+
+#[derive(Error, Debug)]
+pub enum KeyQrCodeError {
+    #[error("encryption-decryption protocol error")]
+    SymmetricCipher(#[from] SymmetricCipherError),
+    #[error("io error")]
+    Io(#[from] io::Error),
+    #[error("invalid secret key")]
+    SecretKey(#[from] SecretKeyError),
+    #[error("couldn't decode QR code")]
+    QrDecodeError(#[from] QrDecodeError),
+    #[error("failed to decode hex")]
+    HexDecodeError(#[from] hex::FromHexError),
+}
+
+#[derive(Error, Debug)]
+pub enum QrDecodeError {
+    #[error("couldn't decode QR code")]
+    DecodeError(#[from] quircs::DecodeError),
+    #[error("couldn't extract QR code")]
+    ExtractError(#[from] quircs::ExtractError),
+    #[error("QR code payload is not valid uf8")]
+    NonUtf8Payload,
+}
+
+impl KeyQrCode {
+    pub fn generate(key: SecretKey<Ed25519Extended>, password: &[u8]) -> Self {
+        let secret = key.leak_secret();
+        let rng = rand::thread_rng();
+        // this won't fail because we already know it's an ed25519extended key,
+        // so it is safe to unwrap
+        let enc = encrypt(password, secret.as_ref(), rng).unwrap();
+        // Using binary would make the QR codes more compact and probably less
+        // prone to scanning errors.
+        let enc_hex = hex::encode(enc);
+        let inner = QrCode::with_error_correction_level(&enc_hex, EcLevel::H).unwrap();
+
+        KeyQrCode { inner }
+    }
+
+    pub fn write_svg(&self, path: impl AsRef<Path>) -> Result<(), KeyQrCodeError> {
+        let mut out = File::create(path)?;
+        let svg_file = self
+            .inner
+            .render()
+            .quiet_zone(true)
+            .dark_color(svg::Color("#000000"))
+            .light_color(svg::Color("#ffffff"))
+            .build();
+        out.write_all(svg_file.as_bytes())?;
+        out.flush()?;
+        Ok(())
+    }
+
+    pub fn to_img(&self) -> ImageBuffer<Luma<u8>, Vec<u8>> {
+        let qr = &self.inner;
+        let img = qr.render::<Luma<u8>>().build();
+        img
+    }
+
+    pub fn decode(
+        img: DynamicImage,
+        password: &[u8],
+    ) -> Result<Vec<SecretKey<Ed25519Extended>>, KeyQrCodeError> {
+        let mut decoder = quircs::Quirc::default();
+
+        let img = img.into_luma8();
+
+        let codes = decoder.identify(img.width() as usize, img.height() as usize, &img);
+
+        codes
+            .map(|code| -> Result<_, KeyQrCodeError> {
+                let decoded = code
+                    .map_err(QrDecodeError::ExtractError)
+                    .and_then(|c| c.decode().map_err(QrDecodeError::DecodeError))?;
+
+                // TODO: I actually don't know if this can fail
+                let h = std::str::from_utf8(&decoded.payload)
+                    .map_err(|_| QrDecodeError::NonUtf8Payload)?;
+                let encrypted_bytes = hex::decode(h)?;
+                let key = decrypt(password, &encrypted_bytes)?;
+                Ok(SecretKey::from_binary(&key)?)
+            })
+            .collect()
+    }
+}
+
+impl fmt::Display for KeyQrCode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let qr_img = self
+            .inner
+            .render::<unicode::Dense1x2>()
+            .quiet_zone(true)
+            .dark_color(unicode::Dense1x2::Light)
+            .light_color(unicode::Dense1x2::Dark)
+            .build();
+        write!(f, "{}", qr_img)
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub struct QrPin {
+    pub password: [u8; 4],
+}
+
+#[derive(Error, Debug)]
+
+pub enum BadPinError {
+    #[error("The PIN must consist of {PIN_LENGTH} digits, found {0}")]
+    InvalidLength(usize),
+    #[error("Invalid digit {0}")]
+    InvalidDigit(char),
+}
+
+impl FromStr for QrPin {
+    type Err = BadPinError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        if s.chars().count() != PIN_LENGTH {
+            return Err(BadPinError::InvalidLength(s.len()));
+        }
+
+        let mut pwd = [0u8; 4];
+        for (i, digit) in s.chars().enumerate() {
+            pwd[i] = digit.to_digit(10).ok_or(BadPinError::InvalidDigit(digit))? as u8;
+        }
+        Ok(QrPin { password: pwd })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_pin_successfully() {
+        for (pin, pwd) in &[
+            ("0000", [0, 0, 0, 0]),
+            ("1123", [1, 1, 2, 3]),
+            ("0002", [0, 0, 0, 2]),
+        ] {
+            let qr_pin = QrPin::from_str(pin).unwrap();
+            assert_eq!(qr_pin, QrPin { password: *pwd })
+        }
+    }
+    #[test]
+    fn pins_that_do_not_satisfy_length_reqs_return_error() {
+        for bad_pin in &["", "1", "11", "111", "11111"] {
+            let qr_pin = QrPin::from_str(bad_pin);
+            assert!(qr_pin.is_err(),)
+        }
+    }
+
+    #[test]
+    fn pins_that_do_not_satisfy_content_reqs_return_error() {
+        for bad_pin in &["    ", " 111", "llll", "000u"] {
+            let qr_pin = QrPin::from_str(bad_pin);
+            assert!(qr_pin.is_err(),)
+        }
+    }
+
+    // TODO: Improve into an integration test using a temporary directory.
+    // Leaving here as an example.
+    #[test]
+    fn generate_svg() {
+        const PASSWORD: &[u8] = &[1, 2, 3, 4];
+        let sk = SecretKey::generate(rand::thread_rng());
+        let qr = KeyQrCode::generate(sk, PASSWORD);
+        qr.write_svg("qr-code.svg").unwrap();
+    }
+
+    #[test]
+    fn encode_decode() {
+        const PASSWORD: &[u8] = &[1, 2, 3, 4];
+        let sk = SecretKey::generate(rand::thread_rng());
+        let qr = KeyQrCode::generate(sk.clone(), PASSWORD);
+        let img = qr.to_img();
+        // img.save("qr.png").unwrap();
+        assert_eq!(
+            sk.leak_secret().as_ref(),
+            KeyQrCode::decode(DynamicImage::ImageLuma8(img), PASSWORD).unwrap()[0]
+                .clone()
+                .leak_secret()
+                .as_ref()
+        );
+    }
+}

src/lib.rs

@@ -1,3 +1,4 @@
+pub mod kedqr;
 pub mod logs;
 pub mod notifications;
 pub mod recovery;