Python message signing (#117)

* Python wallet message signing

* message signing example

* .pyi

python/examples/message-signing.py

@@ -0,0 +1,12 @@
+from kaspa import PrivateKey, PublicKey, sign_message, verify_message
+
+if __name__ == "__main__":
+    message = "Hello Kaspa!"
+    private_key = PrivateKey("b7e151628aed2a6abf7158809cf4f3c762e7160f38b4da56a784d9045190cfef")
+    public_key = PublicKey("dff1d77f2a671c5f36183726db2341be58feae1da2deced843240f7b502ba659")
+
+    signature = sign_message(message, private_key)
+    print(f'Signature: {signature}')
+
+    valid_sig = verify_message(message, signature, public_key) 
+    print('Valid sig' if valid_sig else 'Invalid sig')

python/kaspa.pyi

@@ -588,6 +588,11 @@ class Opcodes(Enum):
     OpInvalidOpCode = 0xff
 
 
+def sign_message(message: str, private_key: PrivateKey) -> str: ...
+
+def verify_message(message: str, signature: str, public_key: PublicKey) -> bool: ...
+
+
 class Generator:
 
     def __init__(

python/src/lib.rs

@@ -26,16 +26,18 @@ cfg_if::cfg_if! {
             m.add_class::<kaspa_txscript::python::ScriptBuilder>()?;
             m.add_class::<kaspa_txscript::wasm::opcodes::Opcodes>()?;
 
+            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::message::py_sign_message, m)?)?;
+            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::message::py_verify_message, m)?)?;
+            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::signer::py_sign_transaction, m)?)?;
             m.add_class::<kaspa_wallet_core::python::tx::generator::generator::Generator>()?;
             m.add_class::<kaspa_wallet_core::python::tx::generator::pending::PendingTransaction>()?;
             m.add_class::<kaspa_wallet_core::python::tx::generator::summary::GeneratorSummary>()?;
-            m.add_class::<kaspa_wallet_core::tx::payment::PaymentOutput>()?;
+            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::tx::utils::create_transaction_py, m)?)?;
+            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::tx::utils::create_transactions_py, m)?)?;
             m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::utils::kaspa_to_sompi, m)?)?;
             m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::utils::sompi_to_kaspa, m)?)?;
             m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::utils::sompi_to_kaspa_string_with_suffix, m)?)?;
-            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::tx::utils::create_transaction_py, m)?)?;
-            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::tx::utils::create_transactions_py, m)?)?;
-            m.add_function(wrap_pyfunction!(kaspa_wallet_core::python::signer::py_sign_transaction, m)?)?;
+            m.add_class::<kaspa_wallet_core::tx::payment::PaymentOutput>()?;
 
             m.add_class::<kaspa_wallet_keys::derivation_path::DerivationPath>()?;
             m.add_class::<kaspa_wallet_keys::keypair::Keypair>()?;

wallet/core/src/python/message.rs

@@ -0,0 +1,25 @@
+use crate::imports::*;
+use crate::message::*;
+use kaspa_wallet_keys::privatekey::PrivateKey;
+use kaspa_wallet_keys::publickey::PublicKey;
+
+#[pyfunction]
+#[pyo3(name = "sign_message")]
+pub fn py_sign_message(message: String, private_key: PrivateKey) -> PyResult<String> {
+    let mut privkey_bytes = [0u8; 32];
+    privkey_bytes.copy_from_slice(&private_key.secret_bytes());
+    let pm = PersonalMessage(&message);
+    let sig_vec = sign_message(&pm, &privkey_bytes).map_err(|err| PyException::new_err(format!("{}", err)))?;
+    privkey_bytes.zeroize();
+    Ok(faster_hex::hex_string(sig_vec.as_slice()).into())
+}
+
+#[pyfunction]
+#[pyo3(name = "verify_message")]
+pub fn py_verify_message(message: String, signature: String, public_key: PublicKey) -> PyResult<bool> {
+    let pm = PersonalMessage(&message);
+    let mut signature_bytes = [0u8; 64];
+    faster_hex::hex_decode(signature.as_bytes(), &mut signature_bytes).map_err(|err| PyException::new_err(format!("{}", err)))?;
+
+    Ok(verify_message(&pm, &signature_bytes.to_vec(), &public_key.xonly_public_key).is_ok())
+}

wallet/core/src/python/mod.rs

@@ -1,3 +1,4 @@
+pub mod message;
 pub mod signer;
 pub mod tx;
 pub mod utils;