feat: generate deterministic secrets (#249)

* feat: generate deterministic secrets

* fix: wasm build

* chore: cleanup

* feat: convert hex keyset-id to int

* chore: cleanup

* chore: store keysets in db (WIP)

* chore: use upsert for adding/updating keysets

* feat: store seed in db

* chore: use deterministic secrets for mint and split

* fix: tests

moksha-core/src/dhke.rs

@@ -89,6 +89,7 @@ impl Dhke {
             .ok_or(MokshaCoreError::NoValidPointFound)
     }
 
+    // FIXME: use SecretKey instead of &[u8] for blinding factor
     pub fn step1_alice(
         &self,
         secret_msg: impl Into<String>,

moksha-core/src/primitives.rs

@@ -136,6 +136,16 @@ pub enum CurrencyUnit {
     Usd,
 }
 
+impl From<String> for CurrencyUnit {
+    fn from(unit: String) -> Self {
+        match unit.to_lowercase().as_str() {
+            "sat" => Self::Sat,
+            "usd" => Self::Usd,
+            _ => panic!("Unknown currency unit: {}", unit),
+        }
+    }
+}
+
 impl Display for CurrencyUnit {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {

moksha-wallet/Cargo.toml

@@ -24,6 +24,10 @@ async-trait = "0.1.77"
 lightning-invoice = "0.29.0"
 url = "2.5.0"
 dirs = "5.0.1"
+bip32 = { version = "0.5.1", features = ["secp256k1", "std"] }
+bip39 = "2.0.0"
+hex = "0.4.3"
+rand = "0.8.5"
 
 [target.'cfg(target_family = "wasm")'.dependencies]
 gloo-net = { version = "0.5.0" }

moksha-wallet/migrations/20230530061910_init.sql

@@ -9,8 +9,12 @@ CREATE TABLE IF NOT EXISTS proofs (
 );
 
 CREATE TABLE IF NOT EXISTS keysets (
-                id TEXT NOT NULL,
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
                 mint_url TEXT NOT NULL,
+                keyset_id TEXT NOT NULL,
+                currency_unit TEXT NOT NULL,
                 active BOOL DEFAULT TRUE,
-                UNIQUE (id, mint_url)
+                last_index INTEGER,
+                public_keys JSON CHECK (json_valid(public_keys)),
+                UNIQUE (keyset_id, mint_url)
 );

moksha-wallet/migrations/20240329082342_deterministic_secrets.sql

@@ -0,0 +1,6 @@
+-- Add migration script here
+CREATE TABLE seed (
+    id INTEGER PRIMARY KEY CHECK (id = 1),
+    seed_words TEXT NOT NULL
+    -- other columns
+);

moksha-wallet/src/error.rs

@@ -42,6 +42,7 @@ pub enum MokshaWalletError {
     #[cfg(not(target_arch = "wasm32"))]
     #[error("Sqlite Error {0}")]
     Sqlite(#[from] sqlx::sqlite::SqliteError),
+
     #[error("Utf8 Error {0}")]
     Utf8(#[from] FromUtf8Error),
 
@@ -62,4 +63,19 @@ pub enum MokshaWalletError {
 
     #[error("Unsupported version: Only mints with /v1 api are supported")]
     UnsupportedApiVersion,
+
+    #[error("Bip32Error {0}")]
+    Bip32(#[from] bip32::Error),
+
+    #[error("Bip39Error {0}")]
+    Bip39(#[from] bip39::Error),
+
+    #[error("Secp256k1 {0}")]
+    Secp256k1(#[from] secp256k1::Error),
+
+    #[error("Primarykey not set for keyset")]
+    IdNotSet,
+
+    #[error("Found multiple seeds in the database. This is not supported.")]
+    MultipleSeeds,
 }

moksha-wallet/src/lib.rs

@@ -4,4 +4,5 @@ pub mod config_path;
 pub mod error;
 pub mod http;
 pub mod localstore;
+pub mod secret;
 pub mod wallet;