Generate a single receiving address for burner/gift card without cloud

libzkbob-rs-wasm/src/keys.rs

@@ -1,10 +1,33 @@
-use libzkbob_rs::libzeropool::fawkes_crypto::ff_uint::Uint;
-use libzkbob_rs::keys::reduce_sk as reduce_sk_native;
+use libzkbob_rs::{address::format_address, keys::reduce_sk as reduce_sk_native};
+use libzkbob_rs::libzeropool::{
+    constants,
+    fawkes_crypto::{ff_uint::Uint, rand::Rng},
+    native::{boundednum::BoundedNum, key::derive_key_p_d},
+    POOL_PARAMS,
+};
 use wasm_bindgen::prelude::*;
 
-use crate::Fs;
+use crate::{Fs, PoolParams};
 
 #[wasm_bindgen(js_name = reduceSpendingKey)]
 pub fn reduce_sk(seed: &[u8]) -> Vec<u8> {
     reduce_sk_native::<Fs>(seed).to_uint().0.to_little_endian()
 }
+
+#[wasm_bindgen(js_name = genBurnerAddress)]
+pub fn gen_burner_address(pool_id: u64, seed: &[u8]) -> Result<String, JsValue> {
+    if pool_id >= 1 << 24 {
+        return Err(js_err!("PoolID should be less than {}", 1 << 24));
+    }
+    let mut rng = libzkbob_rs::random::CustomRng;
+
+    let sk = reduce_sk_native::<Fs>(seed);
+
+    let keys = libzkbob_rs::keys::Keys::derive(sk, &*POOL_PARAMS);
+
+    let d: BoundedNum<_, { constants::DIVERSIFIER_SIZE_BITS }> = rng.gen();
+
+    let pk_d = derive_key_p_d(d.to_num(), keys.eta, &*POOL_PARAMS);
+
+    Ok(format_address::<PoolParams>(d, pk_d.x))
+}