fixed #687 - PKCS8 key encryption not working (#688)

Author: Eugeny

russh/src/keys/format/pkcs8.rs

@@ -123,7 +123,7 @@ pub fn encode_pkcs8_encrypted(
 
     use rand_core::Rng;
     let mut rng = safe_rng();
-    let mut salt = [0; 64];
+    let mut salt = [0; 32];
     rng.fill_bytes(&mut salt);
     let mut iv = [0; 16];
     rng.fill_bytes(&mut iv);

russh/src/keys/format/tests.rs

@@ -1,3 +1,7 @@
+use ssh_key::{Algorithm, PrivateKey};
+
+use crate::keys::pkcs8::{decode_pkcs8, encode_pkcs8_encrypted};
+
 use super::decode_secret_key;
 
 #[test]
@@ -10,3 +14,13 @@ lpQg5vf23Fc9fFrQ9AnQKrb1dgTkoxQ=
 -----END EC PRIVATE KEY-----"#;
     decode_secret_key(key, None).unwrap();
 }
+
+#[test]
+fn test_pkcs8_roundtrip() {
+    let password = b"SomePassword";
+    let original_key = PrivateKey::random(&mut rand::rng(), Algorithm::Ed25519).unwrap();
+
+    let encrypted = encode_pkcs8_encrypted(password, 10, &original_key).unwrap();
+    let decrypted = decode_pkcs8(&encrypted, Some(password)).unwrap();
+    assert_eq!(decrypted, original_key);
+}