parse config file

lib/cluelessh-keys/src/host_keys.rs

@@ -0,0 +1,43 @@
+use std::collections::HashSet;
+
+use thiserror::Error;
+
+use crate::private::PlaintextPrivateKey;
+
+/// A set of host keys, ensuring there are no duplicated algorithms.
+#[derive(Debug, Default)]
+pub struct HostKeySet {
+    algs: HashSet<&'static str>,
+    keys: Vec<PlaintextPrivateKey>,
+}
+
+impl HostKeySet {
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn into_keys(self) -> Vec<PlaintextPrivateKey> {
+        self.keys
+    }
+
+    pub fn insert(&mut self, key: PlaintextPrivateKey) -> Result<(), DuplicateHostKeyAlgorithm> {
+        let alg = key.private_key.algorithm_name();
+
+        let newly_inserted = self.algs.insert(alg);
+        if !newly_inserted {
+            return Err(DuplicateHostKeyAlgorithm { alg });
+        }
+
+        self.keys.push(key);
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, Error)]
+#[error("another host key with algorithm {alg} has already been loaded")]
+pub struct DuplicateHostKeyAlgorithm {
+    alg: &'static str,
+}
+
+// TODO: write tests

lib/cluelessh-keys/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod authorized_keys;
 mod crypto;
+pub mod host_keys;
 pub mod private;
 pub mod public;
 pub mod signature;