reduced redundant code

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fido2luks"
-version = "0.2.4"
+version = "0.2.7"
 authors = ["shimunn <shimun@shimun.net>"]
 edition = "2018"
 
@@ -14,9 +14,7 @@ categories = ["command-line-utilities"]
 license-file = "LICENSE"
 
 [dependencies]
-ctap_hmac = "0.2.1"
-
-
+ctap_hmac = { version="0.4.2", features = ["request_multiple"] }
 hex = "0.3.2"
 ring = "0.13.5"
 failure = "0.1.5"

README.md

@@ -9,7 +9,7 @@ Note: This has only been tested under Fedora 31 using a Solo Key, Trezor Model T
 ### Prerequisites
 
 ```
-dnf install cargo cryptsetup-devel -y
+dnf install clang cargo cryptsetup-devel -y
 ```
 
 ### Device

src/cli.rs

@@ -4,19 +4,21 @@ use crate::*;
 
 use structopt::StructOpt;
 
-use failure::_core::fmt::{Error, Formatter};
+use ctap::{FidoCredential, FidoErrorKind};
+use failure::_core::fmt::{Display, Error, Formatter};
 use failure::_core::str::FromStr;
 use failure::_core::time::Duration;
 use std::io::Write;
-
 use std::process::exit;
 use std::thread;
 
+use crate::util::sha256;
 use std::time::SystemTime;
-#[derive(Debug, Eq, PartialEq, Clone)]
-pub struct HexEncoded(Vec<u8>);
 
-impl std::fmt::Display for HexEncoded {
+#[derive(Debug, Eq, PartialEq, Clone)]
+pub struct HexEncoded(pub Vec<u8>);
+
+impl Display for HexEncoded {
     fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
         f.write_str(&hex::encode(&self.0))
     }
@@ -30,20 +32,73 @@ impl FromStr for HexEncoded {
     }
 }
 
+#[derive(Debug, Eq, PartialEq, Clone)]
+pub struct CommaSeparated<T: FromStr + Display>(pub Vec<T>);
+
+impl<T: Display + FromStr> Display for CommaSeparated<T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+        for i in &self.0 {
+            f.write_str(&i.to_string())?;
+            f.write_str(",")?;
+        }
+        Ok(())
+    }
+}
+
+impl<T: Display + FromStr> FromStr for CommaSeparated<T> {
+    type Err = <T as FromStr>::Err;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(CommaSeparated(
+            s.split(',')
+                .map(|part| <T as FromStr>::from_str(part))
+                .collect::<Result<Vec<_>, _>>()?,
+        ))
+    }
+}
+
 #[derive(Debug, StructOpt)]
-pub struct Args {
-    /// Request passwords via Stdin instead of using the password helper
-    #[structopt(short = "i", long = "interactive")]
-    pub interactive: bool,
-    #[structopt(subcommand)]
-    pub command: Command,
+pub struct Credentials {
+    /// FIDO credential ids, seperated by ',' generate using fido2luks credential
+    #[structopt(name = "credential-id", env = "FIDO2LUKS_CREDENTIAL_ID")]
+    pub ids: CommaSeparated<HexEncoded>,
+}
+
+#[derive(Debug, StructOpt)]
+pub struct AuthenticatorParameters {
+    /// Request a PIN to unlock the authenticator
+    #[structopt(short = "P", long = "pin")]
+    pub pin: bool,
+
+    /// Await for an authenticator to be connected, timeout after n seconds
+    #[structopt(
+        long = "await-dev",
+        name = "await-dev",
+        env = "FIDO2LUKS_DEVICE_AWAIT",
+        default_value = "15"
+    )]
+    pub await_time: u64,
+}
+
+#[derive(Debug, StructOpt)]
+pub struct LuksParameters {
+    #[structopt(env = "FIDO2LUKS_DEVICE")]
+    device: PathBuf,
+
+    /// Try to unlock the device using a specifc keyslot, ignore all other slots
+    #[structopt(long = "slot", env = "FIDO2LUKS_DEVICE_SLOT")]
+    slot: Option<u32>,
 }
 
 #[derive(Debug, StructOpt, Clone)]
-pub struct SecretGeneration {
-    /// FIDO credential id, generate using fido2luks credential
-    #[structopt(name = "credential-id", env = "FIDO2LUKS_CREDENTIAL_ID")]
-    pub credential_id: HexEncoded,
+pub struct LuksModParameters {
+    /// Number of milliseconds required to derive the volume decryption key
+    /// Defaults to 10ms when using an authenticator or the default by cryptsetup when using a password
+    #[structopt(long = "kdf-time", name = "kdf-time")]
+    kdf_time: Option<u64>,
+}
+
+#[derive(Debug, StructOpt)]
+pub struct SecretParameters {
     /// Salt for secret generation, defaults to 'ask'
     ///
     /// Options:{n}
@@ -64,48 +119,71 @@ pub struct SecretGeneration {
         default_value = "/usr/bin/env systemd-ask-password 'Please enter second factor for LUKS disk encryption!'"
     )]
     pub password_helper: PasswordHelper,
-
-    /// Await for an authenticator to be connected, timeout after n seconds
-    #[structopt(
-        long = "await-dev",
-        name = "await-dev",
-        env = "FIDO2LUKS_DEVICE_AWAIT",
-        default_value = "15"
-    )]
-    pub await_authenticator: u64,
 }
 
-impl SecretGeneration {
-    pub fn patch(&self, args: &Args) -> Self {
-        let mut me = self.clone();
-        if args.interactive {
-            me.password_helper = PasswordHelper::Stdin;
+fn derive_secret(
+    credentials: &[HexEncoded],
+    salt: &[u8; 32],
+    timeout: u64,
+    pin: Option<&str>,
+) -> Fido2LuksResult<[u8; 32]> {
+    let timeout = Duration::from_secs(timeout);
+    let start = SystemTime::now();
+
+    while let Ok(el) = start.elapsed() {
+        if el > timeout {
+            return Err(error::Fido2LuksError::NoAuthenticatorError);
         }
-        me
+        if get_devices()
+            .map(|devices| !devices.is_empty())
+            .unwrap_or(false)
+        {
+            break;
+        }
+        thread::sleep(Duration::from_millis(500));
     }
 
-    pub fn obtain_secret(&self) -> Fido2LuksResult<[u8; 32]> {
-        let salt = self.salt.obtain(&self.password_helper)?;
-        let timeout = Duration::from_secs(self.await_authenticator);
-        let start = SystemTime::now();
+    Ok(sha256(&[
+        &perform_challenge(
+            &credentials
+                .iter()
+                .map(|hex| FidoCredential {
+                    id: hex.0.clone(),
+                    public_key: None,
+                })
+                .collect::<Vec<_>>()
+                .iter()
+                .collect::<Vec<_>>()[..],
+            salt,
+            timeout - start.elapsed().unwrap(),
+            pin,
+        )?[..],
+        salt,
+    ]))
+}
 
-        while let Ok(el) = start.elapsed() {
-            if el > timeout {
-                Err(error::Fido2LuksError::NoAuthenticatorError)?;
-            }
-            if get_devices()
-                .map(|devices| !devices.is_empty())
-                .unwrap_or(false)
-            {
-                break;
-            }
-            thread::sleep(Duration::from_millis(500));
-        }
-        Ok(assemble_secret(
-            &perform_challenge(&self.credential_id.0, &salt)?,
-            &salt,
-        ))
-    }
+fn read_pin() -> Fido2LuksResult<String> {
+    util::read_password("Authenticator PIN", false)
+}
+
+#[derive(Debug, StructOpt)]
+pub struct Args {
+    /// Request passwords via Stdin instead of using the password helper
+    #[structopt(short = "i", long = "interactive")]
+    pub interactive: bool,
+    #[structopt(subcommand)]
+    pub command: Command,
+}
+
+#[derive(Debug, StructOpt, Clone)]
+pub struct OtherSecret {
+    /// Use a keyfile instead of a password
+    #[structopt(short = "d", long = "keyfile", conflicts_with = "fido_device")]
+    keyfile: Option<PathBuf>,
+    /// Use another fido device instead of a password
+    /// Note: this requires for the credential fot the other device to be passed as argument as well
+    #[structopt(short = "f", long = "fido-device", conflicts_with = "keyfile")]
+    fido_device: bool,
 }
 
 #[derive(Debug, StructOpt)]
@@ -116,51 +194,72 @@ pub enum Command {
         #[structopt(short = "b", long = "bin")]
         binary: bool,
         #[structopt(flatten)]
-        secret_gen: SecretGeneration,
+        credentials: Credentials,
+        #[structopt(flatten)]
+        authenticator: AuthenticatorParameters,
+        #[structopt(flatten)]
+        secret: SecretParameters,
     },
     /// Adds a generated key to the specified LUKS device
     #[structopt(name = "add-key")]
     AddKey {
-        #[structopt(env = "FIDO2LUKS_DEVICE")]
-        device: PathBuf,
+        #[structopt(flatten)]
+        luks: LuksParameters,
+        #[structopt(flatten)]
+        credentials: Credentials,
+        #[structopt(flatten)]
+        authenticator: AuthenticatorParameters,
+        #[structopt(flatten)]
+        secret: SecretParameters,
         /// Will wipe all other keys
         #[structopt(short = "e", long = "exclusive")]
         exclusive: bool,
-        /// Use a keyfile instead of typing a previous password
-        #[structopt(short = "d", long = "keyfile")]
-        keyfile: Option<PathBuf>,
         #[structopt(flatten)]
-        secret_gen: SecretGeneration,
+        existing_secret: OtherSecret,
+        #[structopt(flatten)]
+        luks_mod: LuksModParameters,
     },
     /// Replace a previously added key with a password
     #[structopt(name = "replace-key")]
     ReplaceKey {
-        #[structopt(env = "FIDO2LUKS_DEVICE")]
-        device: PathBuf,
+        #[structopt(flatten)]
+        luks: LuksParameters,
+        #[structopt(flatten)]
+        credentials: Credentials,
+        #[structopt(flatten)]
+        authenticator: AuthenticatorParameters,
+        #[structopt(flatten)]
+        secret: SecretParameters,
         /// Add the password and keep the key
         #[structopt(short = "a", long = "add-password")]
         add_password: bool,
-        /// Use a keyfile instead of typing a previous password
-        #[structopt(short = "d", long = "keyfile")]
-        keyfile: Option<PathBuf>,
         #[structopt(flatten)]
-        secret_gen: SecretGeneration,
+        replacement: OtherSecret,
+        #[structopt(flatten)]
+        luks_mod: LuksModParameters,
     },
     /// Open the LUKS device
     #[structopt(name = "open")]
     Open {
-        #[structopt(env = "FIDO2LUKS_DEVICE")]
-        device: PathBuf,
+        #[structopt(flatten)]
+        luks: LuksParameters,
         #[structopt(env = "FIDO2LUKS_MAPPER_NAME")]
         name: String,
+        #[structopt(flatten)]
+        credentials: Credentials,
+        #[structopt(flatten)]
+        authenticator: AuthenticatorParameters,
+        #[structopt(flatten)]
+        secret: SecretParameters,
+
         #[structopt(short = "r", long = "max-retries", default_value = "0")]
         retries: i32,
-        #[structopt(flatten)]
-        secret_gen: SecretGeneration,
     },
     /// Generate a new FIDO credential
     #[structopt(name = "credential")]
     Credential {
+        #[structopt(flatten)]
+        authenticator: AuthenticatorParameters,
         /// Name to be displayed on the authenticator if it has a display
         #[structopt(env = "FIDO2LUKS_CREDENTIAL_NAME")]
         name: Option<String>,
@@ -177,96 +276,209 @@ pub fn parse_cmdline() -> Args {
 pub fn run_cli() -> Fido2LuksResult<()> {
     let mut stdout = io::stdout();
     let args = parse_cmdline();
+    let interactive = args.interactive;
     match &args.command {
-        Command::Credential { name } => {
-            let cred = make_credential_id(name.as_ref().map(|n| n.as_ref()))?;
+        Command::Credential {
+            authenticator,
+            name,
+        } => {
+            let pin_string;
+            let pin = if authenticator.pin {
+                pin_string = read_pin()?;
+                Some(pin_string.as_ref())
+            } else {
+                None
+            };
+            let cred = make_credential_id(name.as_ref().map(|n| n.as_ref()), pin)?;
             println!("{}", hex::encode(&cred.id));
             Ok(())
         }
         Command::PrintSecret {
             binary,
-            ref secret_gen,
+            authenticator,
+            credentials,
+            secret,
         } => {
-            let secret = secret_gen.patch(&args).obtain_secret()?;
-            if *binary {
-                stdout.write(&secret[..])?;
+            let pin_string;
+            let pin = if authenticator.pin {
+                pin_string = read_pin()?;
+                Some(pin_string.as_ref())
             } else {
-                stdout.write(hex::encode(&secret[..]).as_bytes())?;
+                None
+            };
+            let salt = if interactive || secret.password_helper == PasswordHelper::Stdin {
+                util::read_password_hashed("Password", false)
+            } else {
+                secret.salt.obtain(&secret.password_helper)
+            }?;
+            let secret = derive_secret(
+                credentials.ids.0.as_slice(),
+                &salt,
+                authenticator.await_time,
+                pin,
+            )?;
+            if *binary {
+                stdout.write_all(&secret[..])?;
+            } else {
+                stdout.write_all(hex::encode(&secret[..]).as_bytes())?;
             }
             Ok(stdout.flush()?)
         }
         Command::AddKey {
-            device,
-            exclusive,
-            keyfile,
-            ref secret_gen,
-        } => {
-            let secret = secret_gen.patch(&args).obtain_secret()?;
-            let old_secret = if let Some(keyfile) = keyfile.clone() {
-                util::read_keyfile(keyfile.clone())
-            } else {
-                util::read_password("Old password", false).map(|p| p.as_bytes().to_vec())
-            }?;
-            let added_slot = luks::add_key(device.clone(), &secret, &old_secret[..], Some(10))?;
-            if *exclusive {
-                let destroyed = luks::remove_keyslots(&device, &[added_slot])?;
-                println!(
-                    "Added to key to device {}, slot: {}\nRemoved {} old keys",
-                    device.display(),
-                    added_slot,
-                    destroyed
-                );
-            } else {
-                println!(
-                    "Added to key to device {}, slot: {}",
-                    device.display(),
-                    added_slot
-                );
-            }
-            Ok(())
+            luks,
+            authenticator,
+            credentials,
+            secret,
+            luks_mod,
+            existing_secret: other_secret,
+            ..
         }
-        Command::ReplaceKey {
-            device,
-            add_password,
-            keyfile,
-            ref secret_gen,
+        | Command::ReplaceKey {
+            luks,
+            authenticator,
+            credentials,
+            secret,
+            luks_mod,
+            replacement: other_secret,
+            ..
         } => {
-            let secret = secret_gen.patch(&args).obtain_secret()?;
-            let new_secret = if let Some(keyfile) = keyfile.clone() {
-                util::read_keyfile(keyfile.clone())
+            let pin = if authenticator.pin {
+                Some(read_pin()?)
             } else {
-                util::read_password("Password to add", *add_password).map(|p| p.as_bytes().to_vec())
-            }?;
-            let slot = if *add_password {
-                luks::add_key(device, &new_secret[..], &secret, None)
-            } else {
-                luks::replace_key(device, &new_secret[..], &secret, Some(5))
-            }?;
-            println!(
-                "Added to password to device {}, slot: {}",
-                device.display(),
-                slot
-            );
-            Ok(())
+                None
+            };
+            let salt = |q: &str, verify: bool| -> Fido2LuksResult<[u8; 32]> {
+                if interactive || secret.password_helper == PasswordHelper::Stdin {
+                    util::read_password_hashed(q, verify)
+                } else {
+                    secret.salt.obtain(&secret.password_helper)
+                }
+            };
+            let other_secret = |salt_q: &str, verify: bool| -> Fido2LuksResult<Vec<u8>> {
+                match other_secret {
+                    OtherSecret {
+                        keyfile: Some(file),
+                        ..
+                    } => util::read_keyfile(file),
+                    OtherSecret {
+                        fido_device: true, ..
+                    } => Ok(derive_secret(
+                        &credentials.ids.0,
+                        &salt(salt_q, verify)?,
+                        authenticator.await_time,
+                        pin.as_deref(),
+                    )?[..]
+                        .to_vec()),
+                    _ => Ok(util::read_password(salt_q, verify)?.as_bytes().to_vec()),
+                }
+            };
+            let secret = |verify: bool| -> Fido2LuksResult<[u8; 32]> {
+                derive_secret(
+                    &credentials.ids.0,
+                    &salt("Password", verify)?,
+                    authenticator.await_time,
+                    pin.as_deref(),
+                )
+            };
+            // Non overlap
+            match &args.command {
+                Command::AddKey { exclusive, .. } => {
+                    let existing_secret = other_secret("Current password", false)?;
+                    let new_secret = secret(true)?;
+                    let added_slot = luks::add_key(
+                        &luks.device,
+                        &new_secret,
+                        &existing_secret[..],
+                        luks_mod.kdf_time.or(Some(10)),
+                    )?;
+                    if *exclusive {
+                        let destroyed = luks::remove_keyslots(&luks.device, &[added_slot])?;
+                        println!(
+                            "Added to key to device {}, slot: {}\nRemoved {} old keys",
+                            luks.device.display(),
+                            added_slot,
+                            destroyed
+                        );
+                    } else {
+                        println!(
+                            "Added to key to device {}, slot: {}",
+                            luks.device.display(),
+                            added_slot
+                        );
+                    }
+                    Ok(())
+                }
+                Command::ReplaceKey { add_password, .. } => {
+                    let existing_secret = secret(false)?;
+                    let replacement_secret = other_secret("Replacement password", true)?;
+                    let slot = if *add_password {
+                        luks::add_key(
+                            &luks.device,
+                            &replacement_secret[..],
+                            &existing_secret,
+                            luks_mod.kdf_time,
+                        )
+                    } else {
+                        luks::replace_key(
+                            &luks.device,
+                            &replacement_secret[..],
+                            &existing_secret,
+                            luks_mod.kdf_time,
+                        )
+                    }?;
+                    println!(
+                        "Added to password to device {}, slot: {}",
+                        luks.device.display(),
+                        slot
+                    );
+                    Ok(())
+                }
+                _ => unreachable!(),
+            }
         }
         Command::Open {
-            device,
+            luks,
+            authenticator,
+            credentials,
+            secret,
             name,
             retries,
-            ref secret_gen,
         } => {
+            let pin_string;
+            let pin = if authenticator.pin {
+                pin_string = read_pin()?;
+                Some(pin_string.as_ref())
+            } else {
+                None
+            };
+            let salt = |q: &str, verify: bool| -> Fido2LuksResult<[u8; 32]> {
+                if interactive || secret.password_helper == PasswordHelper::Stdin {
+                    util::read_password_hashed(q, verify)
+                } else {
+                    secret.salt.obtain(&secret.password_helper)
+                }
+            };
             let mut retries = *retries;
             loop {
-                let secret = secret_gen.patch(&args).obtain_secret()?;
-                match luks::open_container(&device, &name, &secret) {
-                    Err(e) => match e {
-                        Fido2LuksError::WrongSecret if retries > 0 => {
-                            retries -= 1;
-                            eprintln!("{}", e);
-                            continue;
+                match derive_secret(
+                    &credentials.ids.0,
+                    &salt("Password", false)?,
+                    authenticator.await_time,
+                    pin,
+                )
+                .and_then(|secret| luks::open_container(&luks.device, &name, &secret, luks.slot))
+                {
+                    Err(e) => {
+                        match e {
+                            Fido2LuksError::WrongSecret if retries > 0 => {}
+                            Fido2LuksError::AuthenticatorError { ref cause }
+                                if cause.kind() == FidoErrorKind::Timeout && retries > 0 => {}
+
+                            e => return Err(e),
                         }
-                        e => Err(e)?,
-                    },
+                        retries -= 1;
+                        eprintln!("{}", e);
+                    }
                     res => break res,
                 }
             }

src/config.rs

@@ -24,7 +24,7 @@ impl Default for InputSalt {
 
 impl From<&str> for InputSalt {
     fn from(s: &str) -> Self {
-        let mut parts = s.split(":").into_iter();
+        let mut parts = s.split(':');
         match parts.next() {
             Some("ask") | Some("Ask") => InputSalt::AskPassword,
             Some("file") => InputSalt::File {
@@ -84,9 +84,10 @@ impl InputSalt {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum PasswordHelper {
     Script(String),
+    #[allow(dead_code)]
     Systemd,
     Stdin,
 }
@@ -134,7 +135,7 @@ impl PasswordHelper {
             Systemd => unimplemented!(),
             Stdin => Ok(util::read_password("Password", true)?),
             Script(password_helper) => {
-                let mut helper_parts = password_helper.split(" ");
+                let mut helper_parts = password_helper.split(' ');
 
                 let password = Command::new((&mut helper_parts).next().unwrap())
                     .args(helper_parts)

src/device.rs

@@ -1,91 +1,61 @@
 use crate::error::*;
-use crate::util::sha256;
 
+use crate::util;
 use ctap::{
-    self,
-    extensions::hmac::{FidoHmacCredential, HmacExtension},
-    AuthenticatorOptions, FidoDevice, FidoError, FidoErrorKind, PublicKeyCredentialRpEntity,
-    PublicKeyCredentialUserEntity,
+    self, extensions::hmac::HmacExtension, request_multiple_devices, FidoAssertionRequestBuilder,
+    FidoCredential, FidoCredentialRequestBuilder, FidoDevice, FidoError, FidoErrorKind,
 };
+use std::time::Duration;
 
-const RP_ID: &'static str = "fido2luks";
+const RP_ID: &str = "fido2luks";
 
-fn authenticator_options() -> Option<AuthenticatorOptions> {
-    Some(AuthenticatorOptions {
-        uv: false, //TODO: should get this from config
-        rk: true,
-    })
-}
-
-fn authenticator_rp() -> PublicKeyCredentialRpEntity<'static> {
-    PublicKeyCredentialRpEntity {
-        id: RP_ID,
-        name: None,
-        icon: None,
+pub fn make_credential_id(
+    name: Option<&str>,
+    pin: Option<&str>,
+) -> Fido2LuksResult<FidoCredential> {
+    let mut request = FidoCredentialRequestBuilder::default().rp_id(RP_ID);
+    if let Some(user_name) = name {
+        request = request.user_name(user_name);
     }
-}
-
-fn authenticator_user(name: Option<&str>) -> PublicKeyCredentialUserEntity {
-    PublicKeyCredentialUserEntity {
-        id: &[0u8],
-        name: name.unwrap_or(""),
-        icon: None,
-        display_name: name,
-    }
-}
-
-pub fn make_credential_id(name: Option<&str>) -> Fido2LuksResult<FidoHmacCredential> {
-    let mut errs = Vec::new();
-    match get_devices()? {
-        ref devs if devs.is_empty() => Err(Fido2LuksError::NoAuthenticatorError)?,
-        devs => {
-            for mut dev in devs.into_iter() {
-                match dev
-                    .make_hmac_credential_full(
-                        authenticator_rp(),
-                        authenticator_user(name),
-                        &[0u8; 32],
-                        &[],
-                        authenticator_options(),
-                    )
-                    .map(|cred| cred.into())
-                {
-                    //TODO: make credentials device specific
-                    Ok(cred) => {
-                        return Ok(cred);
-                    }
-                    Err(e) => {
-                        errs.push(e);
-                    }
-                }
-            }
+    let request = request.build().unwrap();
+    let make_credential = |device: &mut FidoDevice| {
+        if let Some(pin) = pin {
+            device.unlock(pin)?;
         }
-    }
-    Err(errs.pop().ok_or(Fido2LuksError::NoAuthenticatorError)?)?
-}
-
-pub fn perform_challenge(credential_id: &[u8], salt: &[u8; 32]) -> Fido2LuksResult<[u8; 32]> {
-    let cred = FidoHmacCredential {
-        id: credential_id.to_vec(),
-        rp_id: RP_ID.to_string(),
+        device.make_hmac_credential(&request)
     };
-    let mut errs = Vec::new();
-    match get_devices()? {
-        ref devs if devs.is_empty() => Err(Fido2LuksError::NoAuthenticatorError)?,
-        devs => {
-            for mut dev in devs.into_iter() {
-                match dev.get_hmac_assertion(&cred, &sha256(&[&salt[..]]), None, None) {
-                    Ok(secret) => {
-                        return Ok(secret.0);
-                    }
-                    Err(e) => {
-                        errs.push(e);
-                    }
-                }
-            }
+    Ok(request_multiple_devices(
+        get_devices()?
+            .iter_mut()
+            .map(|device| (device, &make_credential)),
+        None,
+    )?)
+}
+
+pub fn perform_challenge(
+    credentials: &[&FidoCredential],
+    salt: &[u8; 32],
+    timeout: Duration,
+    pin: Option<&str>,
+) -> Fido2LuksResult<[u8; 32]> {
+    let request = FidoAssertionRequestBuilder::default()
+        .rp_id(RP_ID)
+        .credentials(credentials)
+        .build()
+        .unwrap();
+    let get_assertion = |device: &mut FidoDevice| {
+        if let Some(pin) = pin {
+            device.unlock(pin)?;
         }
-    }
-    Err(errs.pop().ok_or(Fido2LuksError::NoAuthenticatorError)?)?
+        device.get_hmac_assertion(&request, &util::sha256(&[&salt[..]]), None)
+    };
+    let (_, (secret, _)) = request_multiple_devices(
+        get_devices()?
+            .iter_mut()
+            .map(|device| (device, &get_assertion)),
+        Some(timeout),
+    )?;
+    Ok(secret)
 }
 
 pub fn get_devices() -> Fido2LuksResult<Vec<FidoDevice>> {
@@ -94,7 +64,7 @@ pub fn get_devices() -> Fido2LuksResult<Vec<FidoDevice>> {
         match FidoDevice::new(&di) {
             Err(e) => match e.kind() {
                 FidoErrorKind::ParseCtap | FidoErrorKind::DeviceUnsupported => (),
-                err => Err(FidoError::from(err))?,
+                err => return Err(FidoError::from(err).into()),
             },
             Ok(dev) => devices.push(dev),
         }

src/luks.rs

@@ -11,18 +11,18 @@ fn load_device_handle<P: AsRef<Path>>(path: P) -> Fido2LuksResult<CryptDevice> {
         .into_iter()
         .fold(None, |res, format| match res {
             Some(Ok(())) => res,
-            Some(e) => Some(e.or(load(format))),
+            Some(e) => Some(e.or_else(|_| load(format))),
             None => Some(load(format)),
         })
         .unwrap()?;
     Ok(device)
 }
 
-pub fn open_container<P: AsRef<Path>>(path: P, name: &str, secret: &[u8]) -> Fido2LuksResult<()> {
+pub fn open_container<P: AsRef<Path>>(path: P, name: &str, secret: &[u8], slot_hint: Option<u32>) -> Fido2LuksResult<()> {
     let mut device = load_device_handle(path)?;
     device
         .activate_handle()
-        .activate_by_passphrase(Some(name), None, secret, CryptActivateFlags::empty())
+        .activate_by_passphrase(Some(name), slot_hint, secret, CryptActivateFlags::empty())
         .map(|_slot| ())
         .map_err(|_e| Fido2LuksError::WrongSecret)
 }
@@ -34,7 +34,6 @@ pub fn add_key<P: AsRef<Path>>(
     iteration_time: Option<u64>,
 ) -> Fido2LuksResult<u32> {
     let mut device = load_device_handle(path)?;
-    // Set iteration time not sure wether this applies to luks2 as well
     if let Some(millis) = iteration_time {
         device.settings_handle().set_iteration_time(millis)
     }
@@ -46,10 +45,10 @@ pub fn add_key<P: AsRef<Path>>(
 
 pub fn remove_keyslots<P: AsRef<Path>>(path: P, exclude: &[u32]) -> Fido2LuksResult<u32> {
     let mut device = load_device_handle(path)?;
-    let mut slot = 0;
     let mut handle;
     let mut destroyed = 0;
-    loop {
+    //TODO: detect how many keyslots there are instead of trying within a given range
+    for slot in 0..1024 {
         handle = device.keyslot_handle(Some(slot));
         match handle.status()? {
             KeyslotInfo::Inactive => continue,
@@ -59,11 +58,9 @@ pub fn remove_keyslots<P: AsRef<Path>>(path: P, exclude: &[u32]) -> Fido2LuksRes
             }
             _ => (),
         }
-        match handle.status()? {
-            KeyslotInfo::ActiveLast => break,
-            _ => (),
+        if let KeyslotInfo::ActiveLast = handle.status()? {
+            break;
         }
-        slot += 1;
     }
     Ok(destroyed)
 }

src/main.rs

@@ -16,10 +16,6 @@ mod error;
 mod luks;
 mod util;
 
-fn assemble_secret(hmac_result: &[u8], salt: &[u8]) -> [u8; 32] {
-    util::sha256(&[salt, hmac_result])
-}
-
 fn main() -> Fido2LuksResult<()> {
     match run_cli() {
         Err(e) => {
@@ -32,20 +28,3 @@ fn main() -> Fido2LuksResult<()> {
         _ => exit(0),
     }
 }
-
-#[cfg(test)]
-mod test {
-
-    use super::*;
-
-    #[test]
-    fn test_assemble_secret() {
-        assert_eq!(
-            assemble_secret(b"abc", b"def"),
-            [
-                46, 82, 82, 140, 142, 159, 249, 196, 227, 160, 142, 72, 151, 77, 59, 62, 180, 36,
-                33, 47, 241, 94, 17, 232, 133, 103, 247, 32, 152, 253, 43, 19
-            ]
-        )
-    }
-}

src/util.rs

@@ -4,7 +4,7 @@ use std::fs::File;
 use std::io::Read;
 use std::path::PathBuf;
 
-pub fn sha256<'a>(messages: &[&[u8]]) -> [u8; 32] {
+pub fn sha256(messages: &[&[u8]]) -> [u8; 32] {
     let mut digest = digest::Context::new(&digest::SHA256);
     for m in messages.iter() {
         digest.update(m);
@@ -23,12 +23,16 @@ pub fn read_password(q: &str, verify: bool) -> Fido2LuksResult<String> {
         {
             Err(Fido2LuksError::AskPassError {
                 cause: AskPassError::Mismatch,
-            })?
+            })
         }
         pass => Ok(pass),
     }
 }
 
+pub fn read_password_hashed(q: &str, verify: bool) -> Fido2LuksResult<[u8; 32]> {
+    read_password(q, verify).map(|pass| sha256(&[pass.as_bytes()]))
+}
+
 pub fn read_keyfile<P: Into<PathBuf>>(path: P) -> Fido2LuksResult<Vec<u8>> {
     let mut file = File::open(path.into())?;
     let mut key = Vec::new();