feat(security): release v0.7.0 with comprehensive security hardening (S-01 to S-11)

src/recovery.rs

@@ -6,8 +6,8 @@ use anyhow::{bail, Context, Result};
 use serde::{Deserialize, Serialize};
 
 use crate::crypto::{
-    derive_kek, generate_dummy_slot, mnemonic_to_dek, wrap_slot0_payload,
-    wrap_slot1_payload, KdfParams, FORMAT_VERSION,
+    decrypt_chunk, derive_kek, generate_dummy_slot, mnemonic_to_dek, validate_password,
+    wrap_slot0_payload, wrap_slot1_payload, KdfParams, FORMAT_VERSION,
 };
 use crate::storage::{ContainerMeta, Database, SlotMeta};
 
@@ -222,6 +222,30 @@ pub fn restore_header_backup(container_path: &Path, backup_path: &Path) -> Resul
     Ok(())
 }
 
+/// Ermittelt automatisch, ob ein Notfallschlüssel zu Slot 0 (Standard/Decoy) oder Slot 1 (Hidden Vault) gehört (S-05).
+pub fn detect_recovery_key_slot(db: &Database, dek: &[u8; 32], version: u32) -> Result<u32> {
+    if let Ok(Some(carrier_id)) = db.find_carrier_node_id() {
+        if let Ok(Some(chunk0)) = db.read_chunk(carrier_id, 0) {
+            let is_dek0 = decrypt_chunk(
+                dek,
+                carrier_id,
+                0,
+                &chunk0.ciphertext,
+                &chunk0.nonce,
+                &chunk0.tag,
+                version,
+            )
+            .is_ok();
+            if is_dek0 {
+                return Ok(0);
+            } else {
+                return Ok(1);
+            }
+        }
+    }
+    Ok(0)
+}
+
 /// Rekonstruiert einen Slot des Container-Headers mithilfe des 24-Wort BIP-39 Notfallschlüssels
 /// und initialisiert ein neues Master-Passwort für den entsprechenden Slot (0 = Decoy, 1 = Hidden Vault).
 pub fn restore_slot_from_recovery_key(
@@ -229,14 +253,13 @@ pub fn restore_slot_from_recovery_key(
     recovery_key: &str,
     new_password: &str,
     target_slot_id: u32,
+    dek_0: Option<&[u8; 32]>,
 ) -> Result<()> {
     if !container_path.exists() {
         bail!("Containerdatei '{}' existiert nicht.", container_path.display());
     }
 
-    if new_password.trim().is_empty() {
-        bail!("Das neue Master-Passwort darf nicht leer sein.");
-    }
+    validate_password(new_password)?;
 
     // 1. DEK aus 24-Wort-Phrase dekodieren & validieren
     let dek = mnemonic_to_dek(recovery_key)
@@ -258,9 +281,11 @@ pub fn restore_slot_from_recovery_key(
     let mut existing_slots = db.read_slots().unwrap_or_default();
 
     let new_slot = if target_slot_id == 1 {
-        // Für Slot 1 wird DEK_0 benötigt (z. B. aus vorhandenem Slot 0)
-        let dek_0_bytes = [0u8; 32];
-        let (wrapped, nonce, tag) = wrap_slot1_payload(&kek, &dek, &dek_0_bytes, carrier_node_id)?;
+        // Für Slot 1 wird der echte DEK_0 benötigt (S-05)
+        let dek_0_bytes = dek_0.ok_or_else(|| {
+            anyhow::anyhow!("Für die Wiederherstellung von Slot 1 (Hidden Vault) wird der DEK von Slot 0 (Standard-Vault) benötigt.")
+        })?;
+        let (wrapped, nonce, tag) = wrap_slot1_payload(&kek, &dek, dek_0_bytes, carrier_node_id)?;
         SlotMeta {
             slot_id: 1,
             version: FORMAT_VERSION,
@@ -333,7 +358,7 @@ pub fn restore_header_from_recovery_key(
     recovery_key: &str,
     new_password: &str,
 ) -> Result<()> {
-    restore_slot_from_recovery_key(container_path, recovery_key, new_password, 0)
+    restore_slot_from_recovery_key(container_path, recovery_key, new_password, 0, None)
 }
 
 #[cfg(test)]
@@ -358,8 +383,8 @@ mod tests {
         let password = "SuperSecretPassword2026!";
         let salt = generate_salt();
         let kdf_params = KdfParams {
-            memory_cost: 1024,
-            time_cost: 1,
+            memory_cost: crate::crypto::MIN_MEMORY_COST_KIB,
+            time_cost: crate::crypto::MIN_TIME_COST,
             parallelism: 1,
         };
         let kek = derive_kek(password, &salt, &kdf_params).unwrap();
@@ -413,8 +438,8 @@ mod tests {
 
         let salt = generate_salt();
         let kdf_params = KdfParams {
-            memory_cost: 1024,
-            time_cost: 1,
+            memory_cost: crate::crypto::MIN_MEMORY_COST_KIB,
+            time_cost: crate::crypto::MIN_TIME_COST,
             parallelism: 1,
         };
         let kek = derive_kek(old_password, &salt, &kdf_params).unwrap();