[fix] #166: Hash email address

Signed-off-by: Sam H. Smith <sam.henning.smith@protonmail.com>

examples/sign_email.py

@@ -12,8 +12,11 @@
 }
 """)
 
+# Hash the user's email address:
+hashed_email = iroha.hash(b"email@address")
+
 # Sign the user's email address:
-signature = key_pair.sign(b"email@address")
+signature = key_pair.sign(bytes(hashed_email))
 
 # Retrieve the encoded Hex string of the user's `signature`
 print(f"Encoded signature:\n{bytes(signature).hex()}")

src/data_model/crypto.rs

@@ -3,7 +3,9 @@ use pyo3::{
     prelude::*,
 };
 
-use iroha_crypto::{Algorithm, KeyGenConfiguration, KeyPair, PrivateKey, PublicKey, Signature};
+use iroha_crypto::{
+    Algorithm, Hash, KeyGenConfiguration, KeyPair, PrivateKey, PublicKey, Signature,
+};
 
 use super::PyMirror;
 
@@ -132,6 +134,11 @@ impl PySignature {
     }
 }
 
+#[pyfunction]
+fn hash(bytes: &[u8]) -> [u8; Hash::LENGTH] {
+    Hash::new(bytes).into()
+}
+
 #[pyclass(name = "KeyGenConfiguration")]
 #[derive(Clone, derive_more::From, derive_more::Into, derive_more::Deref)]
 pub struct PyKeyGenConfiguration(pub KeyGenConfiguration);
@@ -179,5 +186,6 @@ pub fn register_items(_py: Python<'_>, module: &PyModule) -> PyResult<()> {
     module.add_class::<PyPublicKey>()?;
     module.add_class::<PyKeyPair>()?;
     module.add_class::<PyKeyGenConfiguration>()?;
+    module.add_wrapped(wrap_pyfunction!(hash))?;
     Ok(())
 }