allow another fido device to be used as previous secret

error.rs: typo

.drone.yml

@@ -12,3 +12,23 @@ steps:
    commands:
     - apt update && apt install -y libcryptsetup-dev libkeyutils-dev
     - cargo test
+
+ - name: build
+   image: rust:1.37.0
+   commands:
+    - apt update && apt install -y libcryptsetup-dev libkeyutils-dev
+    - cargo install -f --path . --root .
+   when:
+    event: tag
+ - name: publish
+   image: plugins/github-release
+   settings:
+     api_key:
+      from_secret: github_release
+     files:
+      - bin/fido2luks
+     checksum:
+      - md5
+      - sha256
+   when:
+    event: tag    

Cargo.toml

@@ -1,20 +1,26 @@
 [package]
 name = "fido2luks"
-version = "0.1.0"
+version = "0.2.6"
 authors = ["shimunn <shimun@shimun.net>"]
 edition = "2018"
 
-[dependencies]
+description = "Decrypt your LUKS partition using a FIDO2 compatible authenticator"
-ctap = { git = "https://github.com/shimunn/ctap.git", branch = "hmac_ext" }
+documentation = "https://github.com/shimunn/fido2luks/blob/master/README.md"
-#cryptsetup-rs = "0.2.0"
+homepage = "https://github.com/shimunn/fido2luks"
-cryptsetup-rs = { git = "https://github.com/shimunn/cryptsetup-rs.git", branch = "destroy" }
+repository = "https://github.com/shimunn/fido2luks"
-libcryptsetup-sys = { git = "https://github.com/shimunn/cryptsetup-rs.git", branch = "destroy" }
+readme = "README.md"
+keywords = ["luks", "fido2", "u2f"]
+categories = ["command-line-utilities"]
+license-file = "LICENSE"
 
+[dependencies]
+ctap_hmac = { version="0.4.1", features = ["request_multiple"] }
 hex = "0.3.2"
-rust-crypto = "0.2.36"
+ring = "0.13.5"
 failure = "0.1.5"
 rpassword = "4.0.1"
 structopt = "0.3.2"
+libcryptsetup-rs = { git = "https://github.com/shimunn/libcryptsetup-rs.git", branch = "crypt_load_ptr_null" }
 
 [profile.release]
 lto = true

README.md

@@ -1,8 +1,8 @@
-# fido2luks
+# fido2luks [![Crates.io Version](https://img.shields.io/crates/v/fido2luks.svg)](https://crates.io/crates/fido2luks)
 
-This will allow you to unlock your luks encrypted disk with an fido2 compatable key
+This will allow you to unlock your luks encrypted disk with an fido2 compatible key
 
-Note: This has only been tested under Fedora 30 using a Solo Key
+Note: This has only been tested under Fedora 31 using a Solo Key, Trezor Model T
 
 ## Setup
 
@@ -17,18 +17,22 @@ dnf install cargo cryptsetup-devel -y
 ```
 git clone https://github.com/shimunn/fido2luks.git && cd fido2luks
 
-#Alternativly cargo build --release && sudo cp target/release/fido2luks /usr/bin/
+# Alternativly cargo build --release && sudo cp target/release/fido2luks /usr/bin/
-CARGO_INSTALL_ROOT=/usr sudo -E cargo install -f --path .
+sudo -E cargo install -f --path . --root /usr
 
-echo FIDO2LUKS_CREDENTIAL_ID=$(fido2luks credential) >> fido2luks.conf
+# Copy template
+cp dracut/96luks-2fa/fido2luks.conf /etc/
+# Name is optional but useful if your authenticator has a display
+echo FIDO2LUKS_CREDENTIAL_ID=$(fido2luks credential [NAME]) >> /etc/fido2luks.conf
 
+# Load config into env
 set -a
-. fido2luks.conf
+. /etc/fido2luks.conf
 
-#Repeat for each luks volume
+# Repeat for each luks volume
-sudo -E fido2luks -i addkey /dev/disk/by-uuid/<DISK_UUID>
+sudo -E fido2luks -i add-key /dev/disk/by-uuid/<DISK_UUID>
 
-#Test(only works if the luks container isn't active)
+# Test(only works if the luks container isn't active)
 sudo -E fido2luks -i open /dev/disk/by-uuid/<DISK_UUID> luks-<DISK_UUID>
 
 ```
@@ -43,21 +47,59 @@ sudo make install
 
 ### Grub
 
-Add `rd.luks.2fa=<CREDENTIAL_ID>:<DISK_UUID>` to `GRUB_CMDLINE_LINUX`
+Add `rd.luks.2fa=<CREDENTIAL_ID>:<DISK_UUID>` to `GRUB_CMDLINE_LINUX` in /etc/default/grub
 
-Note: This is only required for your root disk, systemd will try to unlock all other luks partions using the same key if you added it using `fido2luks addkey`
+Note: This is only required for your root disk, systemd will try to unlock all other LUKS partions using the same key if you added it using `fido2luks add-key`
 
 ```
 grub2-mkconfig > /boot/grub2/grub.cfg
 ```
 
+I'd also recommend to copy the executable onto /boot so that it is accessible in case you have to access your disk from a rescue system
+
+```
+mkdir /boot/fido2luks/
+cp /usr/bin/fido2luks /boot/fido2luks/
+cp /etc/fido2luks.conf /boot/fido2luks/
+```
+
 ## Test
 
-Just reboot and see if it works, if thats the case you should remove your old less secure password from your luks header:
+Just reboot and see if it works, if that's the case you should remove your old less secure password from your LUKS header:
 
 ```
-#Recommend in case you lose your authenticator, store this backupfile somewhere safe
+# Recommend in case you lose your authenticator, store this backupfile somewhere safe
 cryptsetup luksHeaderBackup /dev/disk/by-uuid/<DISK_UUID> --header-backup-file luks_backup_<DISK_UUID>
-#There is no turning back if you mess this up, make sure you made a backup
+# There is no turning back if you mess this up, make sure you made a backup
 fido2luks -i add-key --exclusive /dev/disk/by-uuid/<DISK_UUID>
 ```
+
+## Addtional settings
+
+### Password less
+
+Remove your previous secret as described in the next section, in case you've already added one.
+
+Open `/etc/fido2luks.conf` and replace `FIDO2LUKS_SALT=Ask` with `FIDO2LUKS_SALT=string:<YOUR_RANDOM_STRING>`
+but be warned that this password will be included to into your initramfs.
+
+Import the new config into env:
+
+```
+set -a
+. /etc/fido2luks.conf
+```
+
+Then add the new secret to each device and update dracut afterwards `dracut -f`
+
+## Removal
+
+Remove `rd.luks.2fa` from `GRUB_CMDLINE_LINUX` in /etc/default/grub
+
+```
+set -a
+. fido2luks.conf
+sudo -E fido2luks -i replace-key /dev/disk/by-uuid/<DISK_UUID>
+
+sudo rm -rf /usr/lib/dracut/modules.d/96luks-2fa /etc/dracut.conf.d/luks-2fa.conf /etc/fido2luks.conf
+```

dracut/96luks-2fa/fido2luks.conf

@@ -0,0 +1,3 @@
+FIDO2LUKS_SALT=Ask
+FIDO2LUKS_PASSWORD_HELPER=/usr/bin/systemd-ask-password Please enter second factor for LUKS disk encryption
+

dracut/96luks-2fa/luks-2fa-generator.sh

@@ -1,16 +1,15 @@
 #!/bin/bash
 
-NORMAL_DIR="/tmp//run/systemd/system"
+NORMAL_DIR="/run/systemd/system"
 LUKS_2FA_WANTS="/etc/systemd/system/luks-2fa.target.wants"
 
 CRYPTSETUP="/usr/lib/systemd/systemd-cryptsetup"
 FIDO2LUKS="/usr/bin/fido2luks"
-XXD="/usr/bin/xxd"
 MOUNT=$(command -v mount)
 UMOUNT=$(command -v umount)
 
 TIMEOUT=120
-CON_MSG="Please connect your authenicator"
+CON_MSG="Please connect your authenticator"
 
 generate_service () {
         local credential_id=$1 target_uuid=$2 timeout=$3 sd_dir=${4:-$NORMAL_DIR}
@@ -20,6 +19,10 @@ generate_service () {
 
         local crypto_target_service="systemd-cryptsetup@luks\x2d${sd_target_uuid}.service"
         local sd_service="${sd_dir}/luks-2fa@luks\x2d${sd_target_uuid}.service"
+        local fido2luks_args="--bin"
+        if [ ! -z "$timeout" ]; then
+          fido2luks_args="$fido2luks_args --await-dev ${timeout}"
+        fi
         {
                 printf -- "[Unit]"
                 printf -- "\nDescription=%s" "2fa for luks"
@@ -28,19 +31,15 @@ generate_service () {
                 printf -- "\nBefore=%s umount.target luks-2fa.target" "$crypto_target_service"
                 printf -- "\nConflicts=umount.target"
                 printf -- "\nDefaultDependencies=no"
-                printf -- "\nJobTimeoutSec=%s" "$timeout"
+                [ ! -z "$timeout" ] && printf -- "\nJobTimeoutSec=%s" "$timeout"
-
                 printf -- "\n\n[Service]"
                 printf -- "\nType=oneshot"
                 printf -- "\nRemainAfterExit=yes"
-                printf -- "\nEnvironment=FIDO2LUKS_CREDENTIAL_ID='%s'" "$credential_id"
+                printf -- "\nEnvironmentFile=%s" "/etc/fido2luks.conf"
-                printf -- "\nEnvironment=FIDO2LUKS_SALT='%s'" "Ask"
+                [ ! -z "$credential_id" ] && printf -- "\nEnvironment=FIDO2LUKS_CREDENTIAL_ID='%s'" "$credential_id"
-                printf -- "\nEnvironment=FIDO2LUKS_PASSWORD_HELPER='%s'" "/usr/bin/systemd-ask-password \"Disk 2fa password\""
                 printf -- "\nKeyringMode=%s" "shared"
-		printf -- "\nExecStartPre=-/usr/bin/plymouth display-message --text ${CON_MSG}"
+		            printf -- "\nExecStartPre=-/usr/bin/plymouth display-message --text \"${CON_MSG}\""
-		printf -- "\nExecStartPre=-/bin/bash -c \"while ! ${FIDO2LUKS} connected; do /usr/bin/sleep 1; done\""
+                printf -- "\nExecStart=/bin/bash -c \"${FIDO2LUKS} print-secret $fido2luks_args | ${CRYPTSETUP} attach 'luks-%s' '/dev/disk/by-uuid/%s' '/dev/stdin'\"" "$target_uuid" "$target_uuid"
-		printf -- "\nExecStartPre=-/usr/bin/plymouth hide-message --text ${CON_MSG}"
-                printf -- "\nExecStart=/bin/bash -c \"${FIDO2LUKS} print-secret --bin | ${CRYPTSETUP} attach 'luks-%s' '/dev/disk/by-uuid/%s' '/dev/stdin'\"" "$target_uuid" "$target_uuid"
                 printf -- "\nExecStop=${CRYPTSETUP} detach 'luks-%s'" "$target_uuid"
         } > "$sd_service"
 
@@ -50,7 +49,7 @@ generate_service () {
                 printf -- "\nConditionPathExists=!/dev/mapper/luks-%s" "$target_uuid"
         } > "${sd_dir}/${crypto_target_service}.d/drop-in.conf"
 
-       # ln -sf "$sd_service" "${LUKS_2FA_WANTS}/"
+        ln -sf "$sd_service" "${LUKS_2FA_WANTS}/"
 }
 
 parse_cmdline () {
@@ -81,5 +80,4 @@ generate_from_cmdline () {
         done
 }
 
-#generate_from_cmdline
+generate_from_cmdline
-generate_service CRED UUID $timeout

dracut/96luks-2fa/module-setup.sh

@@ -18,6 +18,7 @@ depends () {
 install () {
         inst "$moddir/luks-2fa-generator.sh" "/etc/systemd/system-generators/luks-2fa-generator.sh"
         inst_simple "/usr/bin/fido2luks" "/usr/bin/fido2luks"
+        inst_simple "/etc/fido2luks.conf" "/etc/fido2luks.conf"
         inst "$systemdutildir/systemd-cryptsetup"
         mkdir -p "$initdir/luks-2fa"
 

dracut/Makefile

@@ -15,6 +15,7 @@ help:
 install:
 	cp ${MODULE_CONF_D}/${MODULE_CONF} ${DRACUT_CONF_D}/
 	cp -r ${MODULE_DIR} ${DRACUT_MODULES_D}/
+	cp ${MODULE_DIR}/fido2luks.conf /etc/fido2luks.conf
 	dracut -fv
 clean:
 	rm ${DRACUT_CONF_D}/${MODULE_CONF}

src/cli.rs

@@ -1,69 +1,57 @@
 use crate::error::*;
+use crate::luks;
 use crate::*;
 
-use cryptsetup_rs as luks;
-use cryptsetup_rs::api::{CryptDeviceHandle, CryptDeviceOpenBuilder, Luks1Params};
-use cryptsetup_rs::{CryptDevice, Luks1CryptDevice};
-
-use libcryptsetup_sys::crypt_keyslot_info;
 use structopt::StructOpt;
 
-use std::fs::File;
+use ctap::{FidoCredential, FidoErrorKind};
-use std::io::{Read, Write};
+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;
 
-pub fn add_key_to_luks(device: PathBuf, secret: &[u8; 32], exclusive: bool) -> Fido2LuksResult<u8> {
+use std::time::SystemTime;
-    fn offer_format(
+#[derive(Debug, Eq, PartialEq, Clone)]
-        _dev: CryptDeviceOpenBuilder,
+pub struct HexEncoded(pub Vec<u8>);
-    ) -> Fido2LuksResult<CryptDeviceHandle<Luks1Params>> {
-        unimplemented!()
-    }
-    let dev =
-        || -> luks::device::Result<CryptDeviceOpenBuilder> { luks::open(&device.canonicalize()?) };
 
-    let prev_key_info = rpassword::read_password_from_tty(Some(
+impl Display for HexEncoded {
-        "Please enter your current password or path to a keyfile in order to add a new key: ",
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
-    ))?;
+        f.write_str(&hex::encode(&self.0))
-
-    let prev_key = match prev_key_info.as_ref() {
-        "" => None,
-        keyfile if PathBuf::from(keyfile).exists() => {
-            let mut f = File::open(keyfile)?;
-            let mut key = Vec::new();
-            f.read_to_end(&mut key)?;
-            Some(key)
     }
-        password => Some(Vec::from(password.as_bytes())),
-    };
-
-    let mut handle = match dev()?.luks1() {
-        Ok(handle) => handle,
-        Err(luks::device::Error::BlkidError(_)) => offer_format(dev()?)?,
-        Err(luks::device::Error::CryptsetupError(errno)) => {
-            //if i32::from(errno) == 555
-            dbg!(errno);
-            offer_format(dev()?)?
-        } //TODO: find correct errorno and offer to format as luks
-        err => err?,
-    };
-    handle.set_iteration_time(50);
-    let slot = handle.add_keyslot(secret, prev_key.as_ref().map(|b| b.as_slice()), None)?;
-    if exclusive {
-        for old_slot in 0..8u8 {
-            if old_slot != slot
-                && (handle.keyslot_status(old_slot.into()) == crypt_keyslot_info::CRYPT_SLOT_ACTIVE
-                    || handle.keyslot_status(old_slot.into())
-                        == crypt_keyslot_info::CRYPT_SLOT_ACTIVE_LAST)
-            {
-                handle.destroy_keyslot(old_slot)?;
-            }
-        }
-    }
-    Ok(slot)
 }
 
-pub fn authenticator_connected() -> Fido2LuksResult<bool> {
+impl FromStr for HexEncoded {
-    Ok(!device::get_devices()?.is_empty())
+    type Err = hex::FromHexError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(HexEncoded(hex::decode(s)?))
+    }
+}
+
+#[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)]
@@ -77,19 +65,38 @@ pub struct Args {
 
 #[derive(Debug, StructOpt, Clone)]
 pub struct SecretGeneration {
-    /// FIDO credential id, generate using fido2luks credential
+    /// FIDO credential ids, seperated by ',' generate using fido2luks credential
     #[structopt(name = "credential-id", env = "FIDO2LUKS_CREDENTIAL_ID")]
-    pub credential_id: String,
+    pub credential_ids: CommaSeparated<HexEncoded>,
-    /// Salt for secret generation, defaults to Password
+    /// Salt for secret generation, defaults to 'ask'
-    #[structopt(name = "salt", env = "FIDO2LUKS_SALT", default_value = "Ask")]
+    ///
+    /// Options:{n}
+    ///  - ask              : Prompt user using password helper{n}
+    ///  - file:<PATH>      : Will read <FILE>{n}
+    ///  - string:<STRING>  : Will use <STRING>, which will be handled like a password provided to the 'ask' option{n}
+    #[structopt(
+        name = "salt",
+        long = "salt",
+        env = "FIDO2LUKS_SALT",
+        default_value = "ask"
+    )]
     pub salt: InputSalt,
     /// Script used to obtain passwords, overridden by --interactive flag
     #[structopt(
         name = "password-helper",
         env = "FIDO2LUKS_PASSWORD_HELPER",
-        default_value = "/usr/bin/systemd-ask-password 'Please enter second factor for LUKS disk encryption!'"
+        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 {
@@ -103,13 +110,73 @@ impl SecretGeneration {
 
     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();
+
+        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));
+        }
+        let credentials = &self
+            .credential_ids
+            .0
+            .iter()
+            .map(|HexEncoded(id)| FidoCredential {
+                id: id.to_vec(),
+                public_key: None,
+            })
+            .collect::<Vec<_>>();
+        let credentials = credentials.iter().collect::<Vec<_>>();
         Ok(assemble_secret(
-            &perform_challenge(&self.credential_id, &salt)?,
+            &perform_challenge(&credentials[..], &salt, timeout - start.elapsed().unwrap())?,
             &salt,
         ))
     }
 }
 
+#[derive(Debug, StructOpt, Clone)]
+pub struct LuksSettings {
+    /// 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, 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,
+}
+
+impl OtherSecret {
+    pub fn obtain(
+        &self,
+        secret_gen: &SecretGeneration,
+        verify_password: bool,
+        password_question: &str,
+    ) -> Fido2LuksResult<Vec<u8>> {
+        match &self.keyfile {
+            Some(keyfile) => util::read_keyfile(keyfile.clone()),
+            None if self.fido_device => Ok(Vec::from(&secret_gen.obtain_secret()?[..])),
+            None => util::read_password(password_question, verify_password)
+                .map(|p| p.as_bytes().to_vec()),
+        }
+    }
+}
+
 #[derive(Debug, StructOpt)]
 pub enum Command {
     #[structopt(name = "print-secret")]
@@ -129,7 +196,26 @@ pub enum Command {
         #[structopt(short = "e", long = "exclusive")]
         exclusive: bool,
         #[structopt(flatten)]
+        existing_secret: OtherSecret,
+        #[structopt(flatten)]
         secret_gen: SecretGeneration,
+        #[structopt(flatten)]
+        luks_settings: LuksSettings,
+    },
+    /// Replace a previously added key with a password
+    #[structopt(name = "replace-key")]
+    ReplaceKey {
+        #[structopt(env = "FIDO2LUKS_DEVICE")]
+        device: PathBuf,
+        /// Add the password and keep the key
+        #[structopt(short = "a", long = "add-password")]
+        add_password: bool,
+        #[structopt(flatten)]
+        replacement: OtherSecret,
+        #[structopt(flatten)]
+        secret_gen: SecretGeneration,
+        #[structopt(flatten)]
+        luks_settings: LuksSettings,
     },
     /// Open the LUKS device
     #[structopt(name = "open")]
@@ -138,12 +224,18 @@ pub enum Command {
         device: PathBuf,
         #[structopt(env = "FIDO2LUKS_MAPPER_NAME")]
         name: String,
+        #[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,
+    Credential {
+        /// Name to be displayed on the authenticator if it has a display
+        #[structopt(env = "FIDO2LUKS_CREDENTIAL_NAME")]
+        name: Option<String>,
+    },
     /// Check if an authenticator is connected
     #[structopt(name = "connected")]
     Connected,
@@ -157,8 +249,8 @@ pub fn run_cli() -> Fido2LuksResult<()> {
     let mut stdout = io::stdout();
     let args = parse_cmdline();
     match &args.command {
-        Command::Credential => {
+        Command::Credential { name } => {
-            let cred = make_credential_id()?;
+            let cred = make_credential_id(name.as_ref().map(|n| n.as_ref()))?;
             println!("{}", hex::encode(&cred.id));
             Ok(())
         }
@@ -177,13 +269,54 @@ pub fn run_cli() -> Fido2LuksResult<()> {
         Command::AddKey {
             device,
             exclusive,
+            existing_secret,
             ref secret_gen,
+            luks_settings,
         } => {
-            let secret = secret_gen.patch(&args).obtain_secret()?;
+            let secret_gen = secret_gen.patch(&args);
-            let slot = add_key_to_luks(device.clone(), &secret, *exclusive)?;
+            let old_secret = existing_secret.obtain(&secret_gen, false, "Existing password")?;
+            let secret = secret_gen.obtain_secret()?;
+            let added_slot = luks::add_key(
+                device.clone(),
+                &secret,
+                &old_secret[..],
+                luks_settings.kdf_time.or(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(())
+        }
+        Command::ReplaceKey {
+            device,
+            add_password,
+            replacement,
+            ref secret_gen,
+            luks_settings,
+        } => {
+            let secret_gen = secret_gen.patch(&args);
+            let secret = secret_gen.patch(&args).obtain_secret()?;
+            let new_secret = replacement.obtain(&secret_gen, true, "Replacement password")?;
+            let slot = if *add_password {
+                luks::add_key(device, &new_secret[..], &secret, luks_settings.kdf_time)
+            } else {
+                luks::replace_key(device, &new_secret[..], &secret, luks_settings.kdf_time)
+            }?;
+            println!(
+                "Added to password to device {}, slot: {}",
+                device.display(),
                 slot
             );
             Ok(())
@@ -191,10 +324,33 @@ pub fn run_cli() -> Fido2LuksResult<()> {
         Command::Open {
             device,
             name,
+            retries,
             ref secret_gen,
         } => {
-            let secret = secret_gen.patch(&args).obtain_secret()?;
+            let mut retries = *retries;
-            open_container(&device, &name, &secret)
+            loop {
+                match secret_gen
+                    .patch(&args)
+                    .obtain_secret()
+                    .and_then(|secret| luks::open_container(&device, &name, &secret))
+                {
+                    Err(e) => {
+                        match e {
+                            Fido2LuksError::WrongSecret if retries > 0 => (),
+                            Fido2LuksError::AuthenticatorError { ref cause }
+                                if cause.kind() == FidoErrorKind::Timeout && retries > 0 =>
+                            {
+                                ()
+                            }
+
+                            e => break Err(e)?,
+                        }
+                        retries -= 1;
+                        eprintln!("{}", e);
+                    }
+                    res => break res,
+                }
+            }
         }
         Command::Connected => match get_devices() {
             Ok(ref devs) if !devs.is_empty() => {

src/config.rs

@@ -1,7 +1,6 @@
 use crate::error::*;
 use crate::*;
-use crypto::digest::Digest;
+use ring::digest;
-use crypto::sha2::Sha256;
 
 use std::fmt;
 use std::fs::File;
@@ -10,11 +9,11 @@ use std::path::PathBuf;
 use std::process::Command;
 use std::str::FromStr;
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum InputSalt {
     AskPassword,
+    String(String),
     File { path: PathBuf },
-    Both { path: PathBuf },
 }
 
 impl Default for InputSalt {
@@ -25,10 +24,14 @@ impl Default for InputSalt {
 
 impl From<&str> for InputSalt {
     fn from(s: &str) -> Self {
-        if PathBuf::from(s).exists() && s != "Ask" {
+        let mut parts = s.split(":").into_iter();
-            InputSalt::File { path: s.into() }
+        match parts.next() {
-        } else {
+            Some("ask") | Some("Ask") => InputSalt::AskPassword,
-            InputSalt::AskPassword
+            Some("file") => InputSalt::File {
+                path: parts.collect::<Vec<_>>().join(":").into(),
+            },
+            Some("string") => InputSalt::String(parts.collect::<Vec<_>>().join(":")),
+            _ => Self::default(),
         }
     }
 }
@@ -45,15 +48,15 @@ impl fmt::Display for InputSalt {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         f.write_str(&match self {
             InputSalt::AskPassword => "ask".to_string(),
-            InputSalt::File { path } => path.display().to_string(),
+            InputSalt::String(s) => ["string", s].join(":"),
-            InputSalt::Both { path } => ["ask", path.display().to_string().as_str()].join(" + "),
+            InputSalt::File { path } => ["file", path.display().to_string().as_str()].join(":"),
         })
     }
 }
 
 impl InputSalt {
     pub fn obtain(&self, password_helper: &PasswordHelper) -> Fido2LuksResult<[u8; 32]> {
-        let mut digest = Sha256::new();
+        let mut digest = digest::Context::new(&digest::SHA256);
         match self {
             InputSalt::File { path } => {
                 let mut do_io = || {
@@ -61,7 +64,7 @@ impl InputSalt {
                     let mut buf = [0u8; 512];
                     loop {
                         let red = reader.read(&mut buf)?;
-                        digest.input(&buf[0..red]);
+                        digest.update(&buf[0..red]);
                         if red == 0 {
                             break;
                         }
@@ -71,15 +74,12 @@ impl InputSalt {
                 do_io().map_err(|cause| Fido2LuksError::KeyfileError { cause })?;
             }
             InputSalt::AskPassword => {
-                digest.input(password_helper.obtain()?.as_bytes());
+                digest.update(password_helper.obtain()?.as_bytes());
-            }
-            InputSalt::Both { path } => {
-                digest.input(&InputSalt::AskPassword.obtain(password_helper)?);
-                digest.input(&InputSalt::File { path: path.clone() }.obtain(password_helper)?)
             }
+            InputSalt::String(s) => digest.update(s.as_bytes()),
         }
         let mut salt = [0u8; 32];
-        digest.result(&mut salt);
+        salt.as_mut().copy_from_slice(digest.finish().as_ref());
         Ok(salt)
     }
 }
@@ -94,7 +94,7 @@ pub enum PasswordHelper {
 impl Default for PasswordHelper {
     fn default() -> Self {
         PasswordHelper::Script(
-            "/usr/bin/systemd-ask-password 'Please enter second factor for LUKS disk encryption!'"
+            "/usr/bin/env systemd-ask-password 'Please enter second factor for LUKS disk encryption!'"
                 .into(),
         )
     }
@@ -132,23 +132,7 @@ impl PasswordHelper {
         use PasswordHelper::*;
         match self {
             Systemd => unimplemented!(),
-            Stdin => Ok(rpassword::read_password_from_tty(Some("Password: "))
+            Stdin => Ok(util::read_password("Password", true)?),
-                .map_err(|e| Fido2LuksError::AskPassError {
-                    cause: AskPassError::IO(e),
-                })
-                .and_then(|pass| {
-                    match rpassword::read_password_from_tty(Some("Password again: ")).map_err(|e| {
-                        Fido2LuksError::AskPassError {
-                            cause: AskPassError::IO(e),
-                        }
-                    }) {
-                        Ok(ref pass2) if &pass == pass2 => Ok(pass),
-                        Ok(_) => Err(Fido2LuksError::AskPassError {
-                            cause: error::AskPassError::Mismatch,
-                        }),
-                        e => e,
-                    }
-                })?),
             Script(password_helper) => {
                 let mut helper_parts = password_helper.split(" ");
 
@@ -164,3 +148,38 @@ impl PasswordHelper {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+
+    use super::*;
+
+    #[test]
+    fn input_salt_from_str() {
+        assert_eq!(
+            "file:/tmp/abc".parse::<InputSalt>().unwrap(),
+            InputSalt::File {
+                path: "/tmp/abc".into()
+            }
+        );
+        assert_eq!(
+            "string:abc".parse::<InputSalt>().unwrap(),
+            InputSalt::String("abc".into())
+        );
+        assert_eq!("ask".parse::<InputSalt>().unwrap(), InputSalt::AskPassword);
+        assert_eq!("lol".parse::<InputSalt>().unwrap(), InputSalt::default());
+    }
+
+    #[test]
+    fn input_salt_obtain() {
+        assert_eq!(
+            InputSalt::String("abc".into())
+                .obtain(&PasswordHelper::Stdin)
+                .unwrap(),
+            [
+                186, 120, 22, 191, 143, 1, 207, 234, 65, 65, 64, 222, 93, 174, 34, 35, 176, 3, 97,
+                163, 150, 23, 122, 156, 180, 16, 255, 97, 242, 0, 21, 173
+            ]
+        )
+    }
+}

src/device.rs

@@ -1,51 +1,46 @@
 use crate::error::*;
 
-use ctap;
+use ctap::{
-use ctap::extensions::hmac::{FidoHmacCredential, HmacExtension};
+    self, extensions::hmac::HmacExtension, request_multiple_devices, FidoAssertionRequestBuilder,
-use ctap::{FidoDevice, FidoError, FidoErrorKind};
+    FidoCredential, FidoCredentialRequestBuilder, FidoDevice, FidoError, FidoErrorKind,
+};
+use std::time::Duration;
 
-pub fn make_credential_id() -> Fido2LuksResult<FidoHmacCredential> {
+const RP_ID: &'static str = "fido2luks";
-    let mut errs = Vec::new();
+
-    match get_devices()? {
+pub fn make_credential_id(name: Option<&str>) -> Fido2LuksResult<FidoCredential> {
-        ref devs if devs.is_empty() => Err(Fido2LuksError::NoAuthenticatorError)?,
+    let mut request = FidoCredentialRequestBuilder::default().rp_id(RP_ID);
-        devs => {
+    if let Some(user_name) = name {
-            for mut dev in devs.into_iter() {
+        request = request.user_name(user_name);
-                match dev.make_hmac_credential() {
-                    Ok(cred) => {
-                        return Ok(cred);
     }
-                    Err(e) => {
+    let request = request.build().unwrap();
-                        errs.push(e);
+    let make_credential = |device: &mut FidoDevice| device.make_hmac_credential(&request);
-                    }
+    Ok(request_multiple_devices(
-                }
+        get_devices()?
-            }
+            .iter_mut()
-        }
+            .map(|device| (device, &make_credential)),
-    }
+        None,
-    Err(errs.pop().ok_or(Fido2LuksError::NoAuthenticatorError)?)?
+    )?)
 }
 
-pub fn perform_challenge(credential_id: &str, salt: &[u8; 32]) -> Fido2LuksResult<[u8; 32]> {
+pub fn perform_challenge(
-    let cred = FidoHmacCredential {
+    credentials: &[&FidoCredential],
-        id: hex::decode(credential_id).unwrap(),
+    salt: &[u8; 32],
-        rp_id: "hmac".to_string(),
+    timeout: Duration,
-    };
+) -> Fido2LuksResult<[u8; 32]> {
-    let mut errs = Vec::new();
+    let request = FidoAssertionRequestBuilder::default()
-    match get_devices()? {
+        .rp_id(RP_ID)
-        ref devs if devs.is_empty() => Err(Fido2LuksError::NoAuthenticatorError)?,
+        .credentials(credentials)
-        devs => {
+        .build()
-            for mut dev in devs.into_iter() {
+        .unwrap();
-                match dev.hmac_challange(&cred, &salt[..]) {
+    let get_assertion = |device: &mut FidoDevice| device.get_hmac_assertion(&request, &salt, None);
-                    Ok(secret) => {
+    let (_, (secret, _)) = request_multiple_devices(
-                        return Ok(secret);
+        get_devices()?
-                    }
+            .iter_mut()
-                    Err(e) => {
+            .map(|device| (device, &get_assertion)),
-                        errs.push(e);
+        Some(timeout),
-                    }
+    )?;
-                }
+    Ok(secret)
-            }
-        }
-    }
-    Err(errs.pop().ok_or(Fido2LuksError::NoAuthenticatorError)?)?
 }
 
 pub fn get_devices() -> Fido2LuksResult<Vec<FidoDevice>> {

src/error.rs

@@ -11,18 +11,33 @@ pub enum Fido2LuksError {
     KeyfileError { cause: io::Error },
     #[fail(display = "authenticator error: {}", cause)]
     AuthenticatorError { cause: ctap::FidoError },
-    #[fail(display = "no authenticator found, please ensure you device is plugged in")]
+    #[fail(display = "no authenticator found, please ensure your device is plugged in")]
     NoAuthenticatorError,
     #[fail(display = "luks err")]
-    LuksError { cause: cryptsetup_rs::device::Error },
+    LuksError {
-    #[fail(display = "no authenticator found, please ensure you device is plugged in")]
+        cause: libcryptsetup_rs::LibcryptErr,
+    },
+    #[fail(display = "no authenticator found, please ensure your device is plugged in")]
     IoError { cause: io::Error },
-    #[fail(display = "failed to parse config, please check formatting and contents")]
+    #[fail(display = "supplied secret isn't valid for this device")]
     WrongSecret,
     #[fail(display = "not an utf8 string")]
     StringEncodingError { cause: FromUtf8Error },
 }
 
+impl Fido2LuksError {
+    pub fn exit_code(&self) -> i32 {
+        use Fido2LuksError::*;
+        match self {
+            AskPassError { .. } | KeyfileError { .. } => 2,
+            AuthenticatorError { .. } => 3,
+            NoAuthenticatorError => 4,
+            WrongSecret => 5,
+            _ => 1,
+        }
+    }
+}
+
 #[derive(Debug, Fail)]
 pub enum AskPassError {
     #[fail(display = "unable to retrieve password: {}", _0)]
@@ -31,6 +46,7 @@ pub enum AskPassError {
     Mismatch,
 }
 
+use libcryptsetup_rs::LibcryptErr;
 use std::string::FromUtf8Error;
 use Fido2LuksError::*;
 
@@ -40,12 +56,16 @@ impl From<FidoError> for Fido2LuksError {
     }
 }
 
-impl From<cryptsetup_rs::device::Error> for Fido2LuksError {
+impl From<LibcryptErr> for Fido2LuksError {
-    fn from(e: cryptsetup_rs::device::Error) -> Self {
+    fn from(e: LibcryptErr) -> Self {
-        LuksError { cause: e }
+        match e {
+            LibcryptErr::IOError(e) if e.raw_os_error().iter().any(|code| code == &1i32) => {
+                WrongSecret
+            }
+            _ => LuksError { cause: e },
+        }
     }
 }
-
 impl From<io::Error> for Fido2LuksError {
     fn from(e: io::Error) -> Self {
         IoError { cause: e }

src/luks.rs

@@ -0,0 +1,73 @@
+use crate::error::*;
+
+use libcryptsetup_rs::{CryptActivateFlags, CryptDevice, CryptInit, KeyslotInfo};
+use std::path::Path;
+
+fn load_device_handle<P: AsRef<Path>>(path: P) -> Fido2LuksResult<CryptDevice> {
+    let mut device = CryptInit::init(path.as_ref())?;
+    Ok(device.context_handle().load::<()>(None, None).map(|_| device)?)
+}
+
+pub fn open_container<P: AsRef<Path>>(path: P, name: &str, secret: &[u8]) -> Fido2LuksResult<()> {
+    let mut device = load_device_handle(path)?;
+    device
+        .activate_handle()
+        .activate_by_passphrase(Some(name), None, secret, CryptActivateFlags::empty())
+        .map(|_slot| ())
+        .map_err(|_e| Fido2LuksError::WrongSecret)
+}
+
+pub fn add_key<P: AsRef<Path>>(
+    path: P,
+    secret: &[u8],
+    old_secret: &[u8],
+    iteration_time: Option<u64>,
+) -> Fido2LuksResult<u32> {
+    let mut device = load_device_handle(path)?;
+    if let Some(millis) = iteration_time {
+        device.settings_handle().set_iteration_time(millis)
+    }
+    let slot = device
+        .keyslot_handle()
+        .add_by_passphrase(None,old_secret, secret)?;
+    Ok(slot)
+}
+
+pub fn remove_keyslots<P: AsRef<Path>>(path: P, exclude: &[u32]) -> Fido2LuksResult<u32> {
+    let mut device = load_device_handle(path)?;
+    let mut handle = device.keyslot_handle();
+    let mut destroyed = 0;
+    //TODO: detect how many keyslots there are instead of trying within a given range
+    for slot in 0..1024 {
+
+        match handle.status(slot)? {
+            KeyslotInfo::Inactive => continue,
+            KeyslotInfo::Active if !exclude.contains(&slot) => {
+                handle.destroy(slot)?;
+                destroyed += 1;
+            }
+            _ => (),
+        }
+        match handle.status(slot)? {
+            KeyslotInfo::ActiveLast => break,
+            _ => (),
+        }
+    }
+    Ok(destroyed)
+}
+
+pub fn replace_key<P: AsRef<Path>>(
+    path: P,
+    secret: &[u8],
+    old_secret: &[u8],
+    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)
+    }
+    Ok(device
+        .keyslot_handle()
+        .change_by_passphrase(None, None, old_secret, secret)? as u32)
+}

src/main.rs

@@ -1,39 +1,51 @@
 #[macro_use]
 extern crate failure;
+extern crate ctap_hmac as ctap;
 use crate::cli::*;
 use crate::config::*;
 use crate::device::*;
 use crate::error::*;
-use crypto::digest::Digest;
+use std::io;
-use crypto::sha2::Sha256;
-use cryptsetup_rs as luks;
-
-use cryptsetup_rs::Luks1CryptDevice;
-use ctap;
-
-use std::io::{self};
 use std::path::PathBuf;
+use std::process::exit;
 
 mod cli;
 mod config;
 mod device;
 mod error;
-
+mod luks;
-fn open_container(device: &PathBuf, name: &str, secret: &[u8; 32]) -> Fido2LuksResult<()> {
+mod util;
-    let mut handle = luks::open(device.canonicalize()?)?.luks1()?;
-    let _slot = handle.activate(name, &secret[..])?;
-    Ok(())
-}
 
 fn assemble_secret(hmac_result: &[u8], salt: &[u8]) -> [u8; 32] {
-    let mut digest = Sha256::new();
+    util::sha256(&[salt, hmac_result])
-    digest.input(salt);
-    digest.input(hmac_result);
-    let mut secret = [0u8; 32];
-    digest.result(&mut secret);
-    secret
 }
 
 fn main() -> Fido2LuksResult<()> {
-    run_cli()
+    match run_cli() {
+        Err(e) => {
+            #[cfg(debug_assertions)]
+            eprintln!("{:?}", e);
+            #[cfg(not(debug_assertions))]
+            eprintln!("{}", e);
+            exit(e.exit_code())
+        }
+        _ => 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

@@ -0,0 +1,37 @@
+use crate::error::*;
+use ring::digest;
+use std::fs::File;
+use std::io::Read;
+use std::path::PathBuf;
+
+pub fn sha256<'a>(messages: &[&[u8]]) -> [u8; 32] {
+    let mut digest = digest::Context::new(&digest::SHA256);
+    for m in messages.iter() {
+        digest.update(m);
+    }
+    let mut secret = [0u8; 32];
+    secret.as_mut().copy_from_slice(digest.finish().as_ref());
+    secret
+}
+
+pub fn read_password(q: &str, verify: bool) -> Fido2LuksResult<String> {
+    match rpassword::read_password_from_tty(Some(&[q, ": "].join("")))? {
+        ref pass
+            if verify
+                && &rpassword::read_password_from_tty(Some(&[q, "(again): "].join(" ")))?
+                    != pass =>
+        {
+            Err(Fido2LuksError::AskPassError {
+                cause: AskPassError::Mismatch,
+            })?
+        }
+        pass => Ok(pass),
+    }
+}
+
+pub fn read_keyfile<P: Into<PathBuf>>(path: P) -> Fido2LuksResult<Vec<u8>> {
+    let mut file = File::open(path.into())?;
+    let mut key = Vec::new();
+    file.read_to_end(&mut key)?;
+    Ok(key)
+}