Add signing/verifying Aleo values

sdk/docs/source/examples.rst

@@ -44,6 +44,18 @@ Working with signatures
     >>> restored = aleo.Signature.from_string(serialized)
     >>> assert account.verify(restored, message)
 
+Working with signatures using Aleo values
+***********************
+
+.. doctest::
+
+    >>> account = aleo.Account()
+    >>> message = '5field'
+    >>> signature = account.sign_value(message)
+    >>> serialized = str(signature)
+    >>> restored = aleo.Signature.from_string(serialized)
+    >>> assert account.verify_value(restored, message)
+
 
 Calling a **transfer_public** function
 **************************************

sdk/python/test.py

@@ -49,6 +49,17 @@ def test_signature_verify(self):
         self.assertFalse(signature.verify(address, bad_message))
         self.assertEqual(signature, aleo.Signature.from_string(c_signature))
 
+    def test_signature_verify_value(self):
+        address = aleo.Address.from_string(
+            "aleo184vuwr5u7u0ha5f5k44067dd2uaqewxx6pe5ltha5pv99wvhfqxqv339h4")
+        c_signature = "sign1m9jrzpea7c8gdd0q7fp7pwszy6ar4du5p03aj8798c7pvwur9qqfhakcuf0xqelct6u8qylr0tkqwt46kngtg7capdlj6qeqkqevyqnavkjwgtm3t90lvxdrjjl07td0k4w5sysm7w22lfhfkqgdk690pcu5an22wssu4q6d3754cljxugdnrnccneldp79m3j5drzxs0s4sx2u5zze"
+        signature = aleo.Signature.from_string(c_signature)
+        message = "5field"
+        bad_message = "5u8"
+        self.assertTrue(signature.verify_value(address, message))
+        self.assertFalse(signature.verify_value(address, bad_message))
+        self.assertEqual(signature, aleo.Signature.from_string(c_signature))
+
     def test_account_sanity(self):
         private_key = aleo.PrivateKey.from_string(
             "APrivateKey1zkp3dQx4WASWYQVWKkq14v3RoQDfY2kbLssUj7iifi1VUQ6")
@@ -65,6 +76,14 @@ def test_account_sanity(self):
         self.assertFalse(account.verify(signature, bad_message))
         self.assertTrue(signature.verify(account.address(), message))
 
+        message_value = "5field"
+        bad_message_value = "5u8"
+        signature_value = account.sign_value(message_value)
+
+        self.assertTrue(account.verify_value(signature_value, message_value))
+        self.assertFalse(account.verify_value(signature_value, bad_message_value))
+        self.assertTrue(signature_value.verify_value(account.address(), message_value))
+
     def test_encrypt_decrypt_sk(self):
         private_key = aleo.PrivateKey.from_string(
             "APrivateKey1zkpJYx2NZeJYB74JHpzvQGpKneTP75Dk8dao6paugZXtCz3")

sdk/src/account/mod.rs

@@ -92,11 +92,21 @@ impl Account {
         self.private_key.sign(message)
     }
 
+    /// Returns a signature for the given message (as an aleo value)
+    fn sign_value(&self, value: &str) -> anyhow::Result<Signature> {
+        self.private_key.sign_value(value)
+    }
+
     /// Verifies the signature of the given message.
     fn verify(&self, signature: &Signature, message: &[u8]) -> bool {
         signature.verify(&self.address, message)
     }
 
+    /// Verifies the signature of the given value.
+    fn verify_value(&self, signature: &Signature, value: &str) -> bool {
+        signature.verify_value(&self.address, value)
+    }
+
     /// Decrypts a record ciphertext with a view key
     fn decrypt(&self, record_ciphertext: &RecordCiphertext) -> anyhow::Result<RecordPlaintext> {
         record_ciphertext.decrypt(&self.view_key)

sdk/src/account/private_key.rs

@@ -77,6 +77,11 @@ impl PrivateKey {
         Signature::sign(self, message)
     }
 
+    /// Returns a signature for the given message (as a field) using the private key.
+    pub fn sign_value(&self, value: &str) -> anyhow::Result<Signature> {
+        Signature::sign_value(self, value)
+    }
+
     /// Returns the signature secret key.
     fn sk_sig(&self) -> Scalar {
         self.0.sk_sig().into()

sdk/src/account/signature.rs

@@ -14,7 +14,11 @@
 // You should have received a copy of the GNU General Public License
 // along with the Aleo SDK library. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::{types::SignatureNative, Address, ComputeKey, PrivateKey, Scalar};
+use crate::{
+    types::{SignatureNative, ValueNative},
+    Address, ComputeKey, PrivateKey, Scalar,
+};
+use snarkvm::console::program::ToFields;
 
 use pyo3::prelude::*;
 use rand::{rngs::StdRng, SeedableRng};
@@ -62,12 +66,31 @@ impl Signature {
             .map(Self)
     }
 
+    /// Returns a signature for the given message (as bytes) using the private key.
+    #[staticmethod]
+    pub fn sign_value(private_key: &PrivateKey, value: &str) -> anyhow::Result<Self> {
+        let fields = ValueNative::from_str(value)?.to_fields()?;
+        private_key
+            .deref()
+            .sign(&fields, &mut StdRng::from_entropy())
+            .map(Self)
+    }
+
     /// Verifies (challenge == challenge') && (address == address') where:
     ///     challenge' := HashToScalar(G^response pk_sig^challenge, pk_sig, pr_sig, address, message)
     pub fn verify(&self, address: &Address, message: &[u8]) -> bool {
         self.0.verify_bytes(address, message)
     }
 
+    /// Verifies (challenge == challenge') && (address == address') where:
+    ///     challenge' := HashToScalar(G^response pk_sig^challenge, pk_sig, pr_sig, address, message)
+    pub fn verify_value(&self, address: &Address, value: &str) -> bool {
+        let Ok(fields) = ValueNative::from_str(value).and_then(|v| v.to_fields()) else {
+            return false;
+        };
+        self.0.verify(address, &fields)
+    }
+
     /// Returns a string representation of the signature.
     fn __str__(&self) -> String {
         self.0.to_string()