cli: Improve passphrase handling

Reduce redundancy in passphrase functions and give better error message
when not using a TTY.

radicle-cli/src/commands/auth.rs

@@ -171,12 +171,12 @@ pub fn authenticate(options: Options, profile: &Profile) -> anyhow::Result<()> {
                 term::success!("Radicle key already in ssh-agent");
                 return Ok(());
             }
-
-            let validator = term::io::PassphraseValidator::new(profile.keystore.clone());
-            let passphrase = if options.stdin {
+            let passphrase = if let Some(phrase) = profile::env::passphrase() {
+                phrase
+            } else if options.stdin {
                 term::passphrase_stdin()?
             } else {
-                term::passphrase(RAD_PASSPHRASE, validator)?
+                term::io::passphrase(term::io::PassphraseValidator::new(profile.keystore.clone()))?
             };
             register(&mut agent, profile, passphrase)?;
 
@@ -191,7 +191,7 @@ pub fn authenticate(options: Options, profile: &Profile) -> anyhow::Result<()> {
     // Try RAD_PASSPHRASE fallback.
     if let Some(passphrase) = profile::env::passphrase() {
         ssh::keystore::MemorySigner::load(&profile.keystore, Some(passphrase))
-            .map_err(|_| anyhow!("RAD_PASSPHRASE failed"))?;
+            .map_err(|_| anyhow!("`{RAD_PASSPHRASE}` is invalid"))?;
         return Ok(());
     };
 

radicle-cli/src/commands/node/control.rs

@@ -31,7 +31,11 @@ pub fn start(
         // Ask passphrase here, otherwise it'll be a fatal error when running the daemon
         // without `RAD_PASSPHRASE`.
         let validator = term::io::PassphraseValidator::new(profile.keystore.clone());
-        let Ok(passphrase) = term::io::passphrase(profile::env::RAD_PASSPHRASE, validator) else {
+        let passphrase = if let Some(phrase) = profile::env::passphrase() {
+            phrase
+        } else if let Ok(phrase) = term::io::passphrase(validator) {
+            phrase
+        } else {
             anyhow::bail!("your radicle passphrase is required to start your node");
         };
         Some((profile::env::RAD_PASSPHRASE, passphrase))

radicle-cli/src/terminal/io.rs

@@ -39,13 +39,22 @@ impl inquire::validator::StringValidator for PassphraseValidator {
     }
 }
 
-/// Get the signer. First we try getting it from ssh-agent, otherwise we prompt the user.
+/// Get the signer. First we try getting it from ssh-agent, otherwise we prompt the user,
+/// if we're connected to a TTY.
 pub fn signer(profile: &Profile) -> anyhow::Result<Box<dyn Signer>> {
     if let Ok(signer) = profile.signer() {
         return Ok(signer);
     }
     let validator = PassphraseValidator::new(profile.keystore.clone());
-    let passphrase = passphrase(RAD_PASSPHRASE, validator)?;
+    let passphrase = match passphrase(validator) {
+        Ok(p) => p,
+        Err(inquire::InquireError::NotTTY) => {
+            return Err(anyhow::anyhow!(
+                "running in non-interactive mode, please set `{RAD_PASSPHRASE}` to unseal your key",
+            ));
+        }
+        Err(e) => return Err(e.into()),
+    };
     let spinner = spinner("Unsealing key...");
     let signer = MemorySigner::load(&profile.keystore, Some(passphrase))?;
 

radicle-term/src/io.rs

@@ -214,22 +214,17 @@ where
     Ok(value)
 }
 
-pub fn passphrase<K: AsRef<OsStr>, V: validator::StringValidator + 'static>(
-    var: K,
+pub fn passphrase<V: validator::StringValidator + 'static>(
     validate: V,
 ) -> Result<Passphrase, inquire::InquireError> {
-    if let Ok(p) = env::var(var) {
-        Ok(Passphrase::from(p))
-    } else {
-        Ok(Passphrase::from(
-            Password::new("Passphrase:")
-                .with_render_config(*CONFIG)
-                .with_display_mode(inquire::PasswordDisplayMode::Masked)
-                .without_confirmation()
-                .with_validator(validate)
-                .prompt()?,
-        ))
-    }
+    Ok(Passphrase::from(
+        Password::new("Passphrase:")
+            .with_render_config(*CONFIG)
+            .with_display_mode(inquire::PasswordDisplayMode::Masked)
+            .without_confirmation()
+            .with_validator(validate)
+            .prompt()?,
+    ))
 }
 
 pub fn passphrase_confirm<K: AsRef<OsStr>>(