feat: implement kyc verifier contract

Cargo.toml

@@ -10,6 +10,7 @@ members = [
     "src/batch",
     "src/utils",
     "src/flash_loan",
+    "src/kyc"
     "src/staking"
 ]
 resolver = "2"

src/kyc/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "kyc-verifier"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+path = "lib.rs"
+doctest = false
+
+[dependencies]
+soroban-sdk = "22.0.0"
+
+[dev-dependencies]
+soroban-sdk = { version = "22.0.0", features = ["testutils"] }

src/kyc/lib.rs

@@ -0,0 +1,57 @@
+#![no_std]
+use soroban_sdk::{contract, contractimpl, contracttype, symbol_short, Address, Env, Bytes, BytesN};
+
+#[contracttype]
+pub enum DataKey {
+    Admin,
+    VerifierPubKey,
+    UserKyc(Address), // ExpiresAt (u64)
+}
+
+#[contract]
+pub struct KycVerifier;
+
+#[contractimpl]
+impl KycVerifier {
+    pub fn initialize(env: Env, admin: Address, verifier_pubkey: BytesN<32>) {
+        if env.storage().instance().has(&DataKey::Admin) {
+            panic!("already initialized");
+        }
+        admin.require_auth();
+        env.storage().instance().set(&DataKey::Admin, &admin);
+        env.storage().instance().set(&DataKey::VerifierPubKey, &verifier_pubkey);
+    }
+
+    pub fn set_kyc_status(env: Env, user: Address, signature: BytesN<64>, expires_at: u64) {
+        // KYC provider signs: user_addr + expires_at
+        let current_time = env.ledger().timestamp();
+        assert!(expires_at > current_time, "proof expired");
+
+        let mut data = Bytes::new(&env);
+        data.append(&user.to_xdr(&env));
+        data.append(&(expires_at as u128).to_be_bytes().as_slice().into()); // Example message data
+
+        // In real cases, we'd hash the data or use a specific format.
+        // For simplicity, let's verify ed25519 signature.
+        let pubkey: BytesN<32> = env.storage().instance().get(&DataKey::VerifierPubKey).unwrap();
+
+        env.crypto().ed25519_verify(&pubkey, &data, &signature);
+
+        env.storage().persistent().set(&DataKey::UserKyc(user.clone()), &expires_at);
+        env.events().publish((symbol_short!("kyc_set"), user), expires_at);
+    }
+
+    pub fn is_kyc_valid(env: Env, user: Address) -> bool {
+        let current_time = env.ledger().timestamp();
+        match env.storage().persistent().get::<_, u64>(&DataKey::UserKyc(user)) {
+            Some(expiry) => expiry > current_time,
+            None => false,
+        }
+    }
+
+    pub fn update_verifier(env: Env, new_pubkey: BytesN<32>) {
+        let admin: Address = env.storage().instance().get(&DataKey::Admin).unwrap();
+        admin.require_auth();
+        env.storage().instance().set(&DataKey::VerifierPubKey, &new_pubkey);
+    }
+}