mount: replace rpassword with rustix::termios

because rpassword unconditionally open()s /dev/tty, it fails with ENXIO
on the console without workarounds like busybox's cttyhack. in contrast,
bcachefs unlock works fine on console, so change the passphrase prompt
logic in mount to be closer to what it is in unlock.

Signed-off-by: Lauri Tirkkonen <[email protected]>
Signed-off-by: Kent Overstreet <[email protected]>

Cargo.toml

@@ -19,12 +19,12 @@ udev = "0.7.0"
 uuid = "1.2.2"
 errno = "0.2"
 either = "1.5"
-rpassword = "7"
 bch_bindgen = { path = "bch_bindgen" }
 byteorder = "1.3"
 strum = { version = "0.26", features = ["derive"] }
 strum_macros = "0.26"
 zeroize = { version = "1", features = ["std", "zeroize_derive"] }
+rustix = { version = "0.38.34", features = ["termios"] }
 
 [dependencies.env_logger]
 version = "0.10"

src/key.rs

@@ -16,6 +16,7 @@ use bch_bindgen::{
 };
 use byteorder::{LittleEndian, ReadBytesExt};
 use log::info;
+use rustix::termios;
 use uuid::Uuid;
 use zeroize::{ZeroizeOnDrop, Zeroizing};
 
@@ -151,9 +152,20 @@ impl Passphrase {
 
     // blocks indefinitely if no input is available on stdin
     pub fn new_from_prompt() -> Result<Self> {
-        let passphrase = Zeroizing::new(rpassword::prompt_password("Enter passphrase: ")?);
+        let old = termios::tcgetattr(stdin())?;
+        let mut new = old.clone();
+        new.local_modes.remove(termios::LocalModes::ECHO);
+        termios::tcsetattr(stdin(), termios::OptionalActions::Flush, &new)?;
 
-        Ok(Self(CString::new(passphrase.trim_end_matches('\n'))?))
+        eprint!("Enter passphrase: ");
+
+        let mut line = Zeroizing::new(String::new());
+        let res = stdin().read_line(&mut line);
+        termios::tcsetattr(stdin(), termios::OptionalActions::Flush, &old)?;
+        eprintln!("");
+        res?;
+
+        Ok(Self(CString::new(line.trim_end_matches('\n'))?))
     }
 
     // blocks indefinitely if no input is available on stdin