sudo

Cargo.lock

@@ -390,6 +390,7 @@ dependencies = [
  "serde_derive",
  "serde_json",
  "structopt",
+ "sudo",
 ]
 
 [[package]]
@@ -987,6 +988,16 @@ dependencies = [
  "syn 1.0.40",
 ]
 
+[[package]]
+name = "sudo"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a88e74edf206f281aff2820aa2066c781331044c770626dcafe19491f214e05"
+dependencies = [
+ "libc",
+ "log",
+]
+
 [[package]]
 name = "syn"
 version = "0.15.44"

Cargo.toml

@@ -25,6 +25,7 @@ serde_json = "1.0.51"
 serde_derive = "1.0.106"
 serde = "1.0.106"
 pamsm = { version = "0.4.1", features = ["libpam"] }
+sudo = "0.5.0"
 
 [build-dependencies]
 ctap_hmac = { version="0.4.2", features = ["request_multiple"] }

src/lib.rs

@@ -17,6 +17,7 @@ use std::collections::{HashMap, HashSet};
 use std::ffi::CStr;
 use std::path::Path;
 use std::str::FromStr;
+use sudo::{self, RunningAs};
 
 pub mod cli_args;
 pub mod device;
@@ -27,7 +28,12 @@ pub mod util;
 struct PamFido2Luks;
 
 impl PamFido2Luks {
-    fn open(&self, user: String, password: String, args: Vec<String>) -> Fido2LuksResult<()> {
+    fn open(
+        &self,
+        user: String,
+        mut password: impl FnMut() -> PamResult<String>,
+        args: Vec<String>,
+    ) -> Fido2LuksResult<()> {
         let args: HashMap<String, String> = args
             .into_iter()
             .filter_map(|arg| {
@@ -55,11 +61,26 @@ impl PamFido2Luks {
             .get("name")
             .map(|name| name.replace("%user%", user.as_str()));
 
+        let attempts = args
+            .get("attempts")
+            .and_then(|a| a.parse::<usize>().ok())
+            .unwrap_or(3);
+
         if let (Some(device), Some(name)) = (device, name) {
             if !Path::new(&device).exists() || Path::new(&format!("/dev/mapper/{}", name)).exists()
             {
                 return Ok(());
             }
+            // root required to mount luks
+            match sudo::check() {
+                RunningAs::User => {
+                    //err
+                    unimplemented!("no root")
+                }
+                _ => {
+                    sudo::escalate_if_needed().unwrap();
+                }
+            }
             let mut device = LuksDevice::load(device)?;
             let mut additional_credentials: HashSet<String> = HashSet::new();
             if device.is_luks2()? {
@@ -79,22 +100,24 @@ impl PamFido2Luks {
                 .collect();
             let credentials: Vec<&FidoCredential> = credentials.iter().collect();
             if !credentials.is_empty() {
-                let salt = util::sha256(&[password.as_bytes()]);
-                let secret = util::sha256(&[
-                    &salt,
-                    &perform_challenge(
-                        &credentials[..],
+                for _ in 0..attempts {
+                    let salt = util::sha256(&[password().expect("Password").as_bytes()]);
+                    let secret = util::sha256(&[
                         &salt,
-                        Duration::from_secs(15),
-                        pin.map(AsRef::as_ref),
-                    )?
-                    .0[..],
-                ]);
-                device.activate(name.as_str(), &secret[..], None)?;
+                        &perform_challenge(
+                            &credentials[..],
+                            &salt,
+                            Duration::from_secs(15),
+                            pin.map(AsRef::as_ref),
+                        )?
+                        .0[..],
+                    ]);
+                    device.activate(name.as_str(), &secret[..], None)?;
+                }
+                Ok(())
             } else {
                 unimplemented!("custom error")
             }
-            unimplemented!()
         } else {
             unimplemented!("custom error")
         }
@@ -107,12 +130,21 @@ impl PamServiceModule for PamFido2Luks {
             Err(_) => return dbg!(PamError::AUTH_ERR),
             Ok(p) => p.map(|s| s.to_str().map(str::to_string).unwrap()),
         };
-        let password = match pamh.get_authtok(None) {
+        let mut password = match pamh.get_authtok(None) {
             Err(_) => return dbg!(PamError::AUTH_ERR),
             Ok(p) => p.map(|s| s.to_str().map(str::to_string).unwrap()),
         };
-        if let (Some(user), Some(password)) = (user, password) {
-            match PamFido2Luks.open(user, password, args) {
+        if let Some(user) = user {
+            match PamFido2Luks.open(
+                user,
+                move || match password.take() {
+                    Some(pass) => Ok(pass),
+                    None => pamh
+                        .conv(Some("Fido2 salt: "), PamMsgStyle::PROMPT_ECHO_OFF)
+                        .map(|s| s.map(|s| s.to_str().unwrap()).unwrap_or("").to_string()),
+                },
+                args,
+            ) {
                 Ok(_) => PamError::SUCCESS,
                 Err(e) => match e {
                     //TODO: output more detailed error