From d7e905f7ebac34ace015764f1dc9037a508b131e Mon Sep 17 00:00:00 2001
From: jane400 <libpaket@j4ne.de>
Date: Wed, 2 Oct 2024 17:45:00 +0200
Subject: [PATCH] feat: libpaket: use secrecy on packstation credentials

---
 libpaket/src/locker/crypto.rs   | 60 +++++++++++++++++++--------------
 libpaket/src/locker/regtoken.rs | 13 ++++---
 2 files changed, 43 insertions(+), 30 deletions(-)

diff --git a/libpaket/src/locker/crypto.rs b/libpaket/src/locker/crypto.rs
index 85f8e94..384491d 100644
--- a/libpaket/src/locker/crypto.rs
+++ b/libpaket/src/locker/crypto.rs
@@ -1,41 +1,53 @@
 use base64::{engine::general_purpose, Engine as _};
-use rand::prelude::*;
-use uuid::Uuid;
-use ed25519_dalek::SigningKey;
 use ed25519_dalek::Signer;
+use ed25519_dalek::SigningKey;
+use rand::prelude::*;
+use secrecy::zeroize::Zeroize;
+use secrecy::ExposeSecret;
+use secrecy::SecretBox;
+use uuid::Uuid;
 
-
+#[derive(Debug)]
 pub struct CustomerKeySeed {
     pub postnumber: String,
-    pub seed: Seed,
+    pub seed: SecretBox<Seed>,
     pub uuid: Uuid,
     pub device_id: Option<String>,
 }
 
-pub struct Seed {
-    bytes: Vec<u8>,
+impl Zeroize for CustomerKeySeed {
+    fn zeroize(&mut self) {
+        self.postnumber.zeroize();
+        self.seed.zeroize();
+        self.uuid.into_bytes().zeroize();
+        self.device_id.zeroize();
+    }
+}
+
+pub struct Seed(Vec<u8>);
+impl Zeroize for Seed {
+    fn zeroize(&mut self) {
+        self.0.zeroize();
+    }
+}
+
+impl From<Vec<u8>> for Seed {
+    fn from(value: Vec<u8>) -> Self {
+        assert_eq!(value.len(), 32);
+        Seed(value)
+    }
 }
 
 impl Seed {
-    pub(self) fn from_bytes(bytes: Vec<u8>) -> Self {
-        assert_eq!(bytes.len(), 32);
-        Seed {
-            bytes: bytes
-        }
-    }
-
     pub fn random() -> Self {
         let mut rng = rand::thread_rng();
-
         let mut bytes: Vec<u8> = vec![0; 32];
-
         rng.fill_bytes(bytes.as_mut_slice());
-
-        Seed { bytes: bytes }
+        Seed (bytes)
     }
 
     pub fn as_bytes(&self) -> &[u8; 32] {
-        (&self.bytes[..]).try_into().unwrap()
+        (&self.0[..]).try_into().unwrap()
     }
 }
 
@@ -43,7 +55,7 @@ impl CustomerKeySeed {
     pub fn new(postnumber: String) -> Self {
         CustomerKeySeed {
             postnumber,
-            seed: Seed::random(),
+            seed: SecretBox::new(Box::new(Seed::random())),
             uuid: uuid::Uuid::new_v4(),
             device_id: None,
         }
@@ -52,7 +64,7 @@ impl CustomerKeySeed {
     pub fn from(postnumber: &String, seed: Vec<u8>, uuid: &Uuid, device_id: String) -> Self {
         CustomerKeySeed {
             postnumber: postnumber.clone(),
-            seed: Seed::from_bytes(seed),
+            seed: SecretBox::new(Box::new(Seed::from(seed))),
             uuid: uuid.clone(),
             device_id: Some(device_id),
         }
@@ -65,17 +77,15 @@ impl CustomerKeySeed {
     }
 
     pub(crate) fn sign(&self, message: &[u8]) -> String {
-        let signing_key = SigningKey::from_bytes(self.seed.as_bytes());
-
+        let signing_key = SigningKey::from_bytes(self.seed.expose_secret().as_bytes());
         let signature = signing_key.sign(message);
-
         let sig_str = general_purpose::STANDARD.encode(signature.to_bytes());
 
         format!("{}.{}", self.uuid.to_string(), sig_str)
     }
 
     pub(crate) fn get_public_key(&self) -> String {
-        let signing_key = SigningKey::from_bytes(self.seed.as_bytes());
+        let signing_key = SigningKey::from_bytes(self.seed.expose_secret().as_bytes());
         let public_bytes = signing_key.verifying_key().to_bytes();
         let public_str = general_purpose::STANDARD.encode(public_bytes);
 
diff --git a/libpaket/src/locker/regtoken.rs b/libpaket/src/locker/regtoken.rs
index a79e25c..dc5afe3 100644
--- a/libpaket/src/locker/regtoken.rs
+++ b/libpaket/src/locker/regtoken.rs
@@ -4,8 +4,11 @@ use sha2::Sha256;
 
 use crate::{LibraryResult, LibraryError};
 
-pub struct RegToken {
-    token: Vec<u8>,
+pub struct RegToken(Vec<u8>);
+impl secrecy::zeroize::Zeroize for RegToken {
+    fn zeroize(&mut self) {
+        self.0.zeroize();
+    }
 }
 
 impl RegToken {
@@ -32,15 +35,15 @@ impl RegToken {
             token.extend(vec![0; 32 - token.len()].iter())
         }
 
-        Ok(RegToken { token })
+        Ok(RegToken(token))
     }
 
     pub fn customer_password(&self) -> String {
-        general_purpose::STANDARD.encode(&self.token[32..])
+        general_purpose::STANDARD.encode(&self.0[32..])
     }
 
     pub fn hmac(&self) -> SimpleHmac<Sha256> {
-        let mac = SimpleHmac::<Sha256>::new_from_slice(&self.token[0..32])
+        let mac = SimpleHmac::<Sha256>::new_from_slice(&self.0[0..32])
             .expect("HMAC can take key of any size");
 
         mac