add nix flake

* obvious password promt

* prompt interaction with FIDO device

.gitignore

@@ -5,4 +5,6 @@
 fido2luks.bash
 fido2luks.elv
 fido2luks.fish
-fido2luks.zsh
+fido2luks.zsh
+result
+result-*

Cargo.lock

@@ -377,7 +377,7 @@ dependencies = [
 
 [[package]]
 name = "fido2luks"
-version = "0.2.15"
+version = "0.2.16"
 dependencies = [
  "ctap_hmac",
  "failure",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fido2luks"
-version = "0.2.15"
+version = "0.2.16"
 authors = ["shimunn <shimun@shimun.net>"]
 edition = "2018"
 
@@ -48,6 +48,7 @@ extended-description = "Decrypt your LUKS partition using a FIDO2 compatible aut
 assets = [
     ["target/release/fido2luks", "usr/bin/", "755"],
     ["fido2luks.bash", "usr/share/bash-completion/completions/fido2luks", "644"],
+    ["pam_mount/fido2luksmounthelper.sh", "usr/bin/", "755"],
     ["initramfs-tools/keyscript.sh", "/lib/cryptsetup/scripts/fido2luks", "755" ],
     ["initramfs-tools/hook/fido2luks.sh", "etc/initramfs-tools/hooks/", "755" ],
     ["initramfs-tools/fido2luks.conf", "etc/", "644"],

PKGBUILD

@@ -21,5 +21,6 @@ build() {
 
 package() {
     install -Dm 755 target/release/${pkgname} -t "${pkgdir}/usr/bin"
+    install -Dm 755 ../pam_mount/fido2luksmounthelper.sh -t "${pkgdir}/usr/bin"
     install -Dm 644 ../fido2luks.bash "${pkgdir}/usr/share/bash-completion/completions/fido2luks"
 }

README.md

@@ -2,7 +2,7 @@
 
 This will allow you to unlock your LUKS encrypted disk with an FIDO2 compatible key.
 
-Note: This has only been tested under Fedora 31, [Ubuntu 20.04](initramfs-tools/), [NixOS](https://nixos.org/nixos/manual/#sec-luks-file-systems-fido2) using a Solo Key, Trezor Model T
+Note: This has only been tested under Fedora 31, [Ubuntu 20.04](initramfs-tools/), [NixOS](https://nixos.org/nixos/manual/#sec-luks-file-systems-fido2) using a Solo Key, Trezor Model T, YubiKey(fw >= [5.2.3](https://support.yubico.com/hc/en-us/articles/360016649319-YubiKey-5-2-3-Enhancements-to-FIDO-2-Support))
 
 ## Setup
 

flake.lock

@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "naersk": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1612192764,
+        "narHash": "sha256-7EnLtZQWP6511G1ZPA7FmJlqAr3hWsAYb24tvTvJ/ec=",
+        "owner": "nmattia",
+        "repo": "naersk",
+        "rev": "6e149bfd726a8ebefa415f2d713ba6d942435abd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nmattia",
+        "repo": "naersk",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1611910458,
+        "narHash": "sha256-//j54S14v9lp3YKizS1WZW3WKwLjGTzvwhHfUAaRBPQ=",
+        "path": "/nix/store/z5g10k571cc5q9yvr0bafzswp0ggawjw-source",
+        "rev": "6e7f25001fe6874f7ae271891f709bbf50a22c45",
+        "type": "path"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "naersk": "naersk",
+        "nixpkgs": "nixpkgs",
+        "utils": "utils"
+      }
+    },
+    "utils": {
+      "locked": {
+        "lastModified": 1610051610,
+        "narHash": "sha256-U9rPz/usA1/Aohhk7Cmc2gBrEEKRzcW4nwPWMPwja4Y=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "3982c9903e93927c2164caa727cd3f6a0e6d14cc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,61 @@
+{
+  description = "Decrypt your LUKS partition using a FIDO2 compatible authenticator";
+
+  inputs = {
+    utils.url = "github:numtide/flake-utils";
+    naersk = {
+      url = "github:nmattia/naersk";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, utils, naersk }:
+    let
+      root = ./.;
+      pname = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package.name;
+      forPkgs = pkgs:
+        let
+          naersk-lib = naersk.lib."${pkgs.system}";
+          buildInputs = with pkgs; [ cryptsetup ];
+          LIBCLANG_PATH = "${pkgs.clang.cc.lib}/lib";
+          nativeBuildInputs = with pkgs; [
+            pkgconfig
+            clang
+          ];
+        in
+        rec {
+          # `nix build`
+          packages.${pname} = naersk-lib.buildPackage {
+            inherit pname root buildInputs nativeBuildInputs LIBCLANG_PATH;
+          };
+          defaultPackage = packages.${pname};
+
+          # `nix run`
+          apps.${pname} = utils.lib.mkApp {
+            drv = packages.${pname};
+          };
+          defaultApp = apps.${pname};
+
+          # `nix flake check`
+          checks = {
+            fmt = with pkgs; runCommandLocal "${pname}-fmt" { buildInputs = [ cargo rustfmt nixpkgs-fmt ]; } ''
+              cd ${root}
+              cargo fmt -- --check
+              nixpkgs-fmt --check *.nix
+              touch $out
+            '';
+          };
+
+          # `nix develop`
+          devShell = pkgs.mkShell {
+            nativeBuildInputs = with pkgs; [ rustc cargo rustfmt nixpkgs-fmt ] ++ nativeBuildInputs;
+            inherit buildInputs LIBCLANG_PATH;
+          };
+        };
+      forSystem = system: forPkgs nixpkgs.legacyPackages."${system}";
+    in
+    (utils.lib.eachSystem [ "aarch64-linux" "i686-linux" "x86_64-linux" ] forSystem) // {
+      overlay = final: prev: (forPkgs final).packages;
+    };
+
+}

pam_mount/fido2luksmounthelper.sh

@@ -0,0 +1,220 @@
+#!/bin/bash
+#
+# This is a rather minimal example Argbash potential
+# Example taken from http://argbash.readthedocs.io/en/stable/example.html
+#
+# ARG_POSITIONAL_SINGLE([operation],[Operation to perform (mount|umount)],[])
+# ARG_OPTIONAL_SINGLE([credentials-type],[c],[Type of the credentials to use (external|embedded)])
+# ARG_OPTIONAL_SINGLE([device],[d],[Name of the device to create])
+# ARG_OPTIONAL_SINGLE([mount-point],[m],[Path of the mount point to use])
+# ARG_OPTIONAL_BOOLEAN([ask-pin],[a],[Ask for a pin],[off])
+# ARG_OPTIONAL_SINGLE([salt],[s],[Salt to use],[""])
+# ARG_HELP([Unlocks/Locks a LUKS volume and mount/unmount it in the given mount point.])
+# ARGBASH_GO()
+# needed because of Argbash --> m4_ignore([
+### START OF CODE GENERATED BY Argbash v2.9.0 one line above ###
+# Argbash is a bash code generator used to get arguments parsing right.
+# Argbash is FREE SOFTWARE, see https://argbash.io for more info
+# Generated online by https://argbash.io/generate
+
+
+die()
+{
+	local _ret="${2:-1}"
+	test "${_PRINT_HELP:-no}" = yes && print_help >&2
+	echo "$1" >&2
+	exit "${_ret}"
+}
+
+
+begins_with_short_option()
+{
+	local first_option all_short_options='cdmash'
+	first_option="${1:0:1}"
+	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
+}
+
+# THE DEFAULTS INITIALIZATION - POSITIONALS
+_positionals=()
+# THE DEFAULTS INITIALIZATION - OPTIONALS
+_arg_credentials_type=
+_arg_device=
+_arg_mount_point=
+_arg_ask_pin="off"
+_arg_salt=""
+
+
+print_help()
+{
+	printf '%s\n' "Unlocks/Locks a LUKS volume and mount/unmount it in the given mount point."
+	printf 'Usage: %s [-c|--credentials-type <arg>] [-d|--device <arg>] [-m|--mount-point <arg>] [-a|--(no-)ask-pin] [-s|--salt <arg>] [-h|--help] <operation>\n' "$0"
+	printf '\t%s\n' "<operation>: Operation to perform (mount|umount)"
+	printf '\t%s\n' "-c, --credentials-type: Type of the credentials to use (external|embedded) (no default)"
+	printf '\t%s\n' "-d, --device: Name of the device to create (no default)"
+	printf '\t%s\n' "-m, --mount-point: Path of the mount point to use (no default)"
+	printf '\t%s\n' "-a, --ask-pin, --no-ask-pin: Ask for a pin (off by default)"
+	printf '\t%s\n' "-s, --salt: Salt to use (default: '""')"
+	printf '\t%s\n' "-h, --help: Prints help"
+}
+
+
+parse_commandline()
+{
+	_positionals_count=0
+	while test $# -gt 0
+	do
+		_key="$1"
+		case "$_key" in
+			-c|--credentials-type)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_credentials_type="$2"
+				shift
+				;;
+			--credentials-type=*)
+				_arg_credentials_type="${_key##--credentials-type=}"
+				;;
+			-c*)
+				_arg_credentials_type="${_key##-c}"
+				;;
+			-d|--device)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_device="$2"
+				shift
+				;;
+			--device=*)
+				_arg_device="${_key##--device=}"
+				;;
+			-d*)
+				_arg_device="${_key##-d}"
+				;;
+			-m|--mount-point)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_mount_point="$2"
+				shift
+				;;
+			--mount-point=*)
+				_arg_mount_point="${_key##--mount-point=}"
+				;;
+			-m*)
+				_arg_mount_point="${_key##-m}"
+				;;
+			-a|--no-ask-pin|--ask-pin)
+				_arg_ask_pin="on"
+				test "${1:0:5}" = "--no-" && _arg_ask_pin="off"
+				;;
+			-a*)
+				_arg_ask_pin="on"
+				_next="${_key##-a}"
+				if test -n "$_next" -a "$_next" != "$_key"
+				then
+					{ begins_with_short_option "$_next" && shift && set -- "-a" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
+				fi
+				;;
+			-s|--salt)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_salt="$2"
+				shift
+				;;
+			--salt=*)
+				_arg_salt="${_key##--salt=}"
+				;;
+			-s*)
+				_arg_salt="${_key##-s}"
+				;;
+			-h|--help)
+				print_help
+				exit 0
+				;;
+			-h*)
+				print_help
+				exit 0
+				;;
+			*)
+				_last_positional="$1"
+				_positionals+=("$_last_positional")
+				_positionals_count=$((_positionals_count + 1))
+				;;
+		esac
+		shift
+	done
+}
+
+
+handle_passed_args_count()
+{
+	local _required_args_string="'operation'"
+	test "${_positionals_count}" -ge 1 || _PRINT_HELP=yes die "FATAL ERROR: Not enough positional arguments - we require exactly 1 (namely: $_required_args_string), but got only ${_positionals_count}." 1
+	test "${_positionals_count}" -le 1 || _PRINT_HELP=yes die "FATAL ERROR: There were spurious positional arguments --- we expect exactly 1 (namely: $_required_args_string), but got ${_positionals_count} (the last one was: '${_last_positional}')." 1
+}
+
+
+assign_positional_args()
+{
+	local _positional_name _shift_for=$1
+	_positional_names="_arg_operation "
+
+	shift "$_shift_for"
+	for _positional_name in ${_positional_names}
+	do
+		test $# -gt 0 || break
+		eval "$_positional_name=\${1}" || die "Error during argument parsing, possibly an Argbash bug." 1
+		shift
+	done
+}
+
+parse_commandline "$@"
+handle_passed_args_count
+assign_positional_args 1 "${_positionals[@]}"
+
+# OTHER STUFF GENERATED BY Argbash
+
+### END OF CODE GENERATED BY Argbash (sortof) ### ])
+# [ <-- needed because of Argbash
+
+if [ -z ${_arg_mount_point} ]; then
+  die "Missing '--mount-point' argument"
+fi
+
+if [ -z ${_arg_device} ]; then
+  die "Missing '--device' argument"
+fi
+
+ASK_PIN=${_arg_ask_pin}
+OPERATION=${_arg_operation}
+DEVICE=${_arg_device}
+DEVICE_NAME=$(sed "s|/|_|g" <<< ${DEVICE})
+MOUNT_POINT=${_arg_mount_point}
+CREDENTIALS_TYPE=${_arg_credentials_type}
+SALT=${_arg_salt}
+CONF_FILE_PATH="/etc/fido2luksmounthelper.conf"
+
+if [ "${OPERATION}" == "mount" ]; then
+	if [ "${CREDENTIALS_TYPE}" == "external" ]; then
+    if  [ -f ${CONF_FILE_PATH} ]; then
+			if [ "${ASK_PIN}" == "on" ]; then
+				read PASSWORD
+			fi
+			CREDENTIALS=$(<${CONF_FILE_PATH})
+		else
+			die "The configuration file '${CONF_FILE_PATH}' is missing. Please create it or use embedded credentials."
+		fi
+		printf ${PASSWORD} | fido2luks open --salt string:${SALT} --pin --pin-source /dev/stdin ${DEVICE} ${DEVICE_NAME} ${CREDENTIALS}
+	elif [ "${CREDENTIALS_TYPE}" == "embedded" ]; then
+		if [ "${ASK_PIN}" == "on" ]; then
+			read PASSWORD
+		fi
+		printf ${PASSWORD} | fido2luks open-token --salt string:${SALT} --pin --pin-source /dev/stdin ${DEVICE} ${DEVICE_NAME}
+	else
+		die "Given credential-type '${CREDENTIALS_TYPE}' is invalid. It must be 'external' or 'embedded'"
+	fi 
+	mount /dev/mapper/${DEVICE_NAME} ${MOUNT_POINT}
+elif [ "${OPERATION}" == "umount" ]; then
+  umount ${MOUNT_POINT}
+  cryptsetup luksClose ${DEVICE_NAME}
+else
+  die "Given operation '${OPERATION}' is invalid. It must be 'mount' or 'unmount'"
+fi
+
+exit 0
+
+# ] <-- needed because of Argbash

src/cli.rs

@@ -71,6 +71,12 @@ pub fn parse_cmdline() -> Args {
     Args::from_args()
 }
 
+pub fn prompt_interaction(interactive: bool) {
+    if interactive {
+        println!("Authorize using your FIDO device");
+    }
+}
+
 pub fn run_cli() -> Fido2LuksResult<()> {
     let mut stdout = io::stdout();
     let args = parse_cmdline();
@@ -109,6 +115,7 @@ pub fn run_cli() -> Fido2LuksResult<()> {
             } else {
                 secret.salt.obtain_sha256(&secret.password_helper)
             }?;
+            prompt_interaction(interactive);
             let (secret, _cred) = derive_secret(
                 credentials.ids.0.as_slice(),
                 &salt,
@@ -164,23 +171,27 @@ pub fn run_cli() -> Fido2LuksResult<()> {
                     } => Ok((util::read_keyfile(file)?, None)),
                     OtherSecret {
                         fido_device: true, ..
-                    } => Ok(derive_secret(
+                    } => {
-                        &credentials.ids.0,
+                        prompt_interaction(interactive);
-                        &salt(salt_q, verify)?,
+                        Ok(derive_secret(
-                        authenticator.await_time,
+                            &credentials.ids.0,
-                        pin.as_deref(),
+                            &salt(salt_q, verify)?,
-                    )
+                            authenticator.await_time,
-                    .map(|(secret, cred)| (secret[..].to_vec(), Some(cred)))?),
+                            pin.as_deref(),
+                        )
+                        .map(|(secret, cred)| (secret[..].to_vec(), Some(cred)))?)
+                    }
                     _ => Ok((
                         util::read_password(salt_q, verify)?.as_bytes().to_vec(),
                         None,
                     )),
                 }
             };
-            let secret = |verify: bool| -> Fido2LuksResult<([u8; 32], FidoCredential)> {
+            let secret = |q: &str, verify: bool| -> Fido2LuksResult<([u8; 32], FidoCredential)> {
+                prompt_interaction(interactive);
                 derive_secret(
                     &credentials.ids.0,
-                    &salt("Password", verify)?,
+                    &salt(q, verify)?,
                     authenticator.await_time,
                     pin.as_deref(),
                 )
@@ -190,7 +201,7 @@ pub fn run_cli() -> Fido2LuksResult<()> {
             match &args.command {
                 Command::AddKey { exclusive, .. } => {
                     let (existing_secret, _) = other_secret("Current password", false)?;
-                    let (new_secret, cred) = secret(true)?;
+                    let (new_secret, cred) = secret("Password to be added", true)?;
                     let added_slot = luks_dev.add_key(
                         &new_secret,
                         &existing_secret[..],
@@ -215,7 +226,7 @@ pub fn run_cli() -> Fido2LuksResult<()> {
                     Ok(())
                 }
                 Command::ReplaceKey { add_password, .. } => {
-                    let (existing_secret, _) = secret(false)?;
+                    let (existing_secret, _) = secret("Current password", false)?;
                     let (replacement_secret, cred) = other_secret("Replacement password", true)?;
                     let slot = if *add_password {
                         luks_dev.add_key(
@@ -274,6 +285,7 @@ pub fn run_cli() -> Fido2LuksResult<()> {
 
             // Cow shouldn't be necessary
             let secret = |credentials: Cow<'_, Vec<HexEncoded>>| {
+                prompt_interaction(interactive);
                 derive_secret(
                     credentials.as_ref(),
                     &salt("Password", false)?,