feat: Change script_signature type to ComSig (#3016)

applications/tari_app_grpc/Cargo.toml

@@ -11,7 +11,7 @@ edition = "2018"
 tari_common_types = { version = "^0.8", path = "../../base_layer/common_types"}
 tari_core = {  path = "../../base_layer/core"}
 tari_wallet = {  path = "../../base_layer/wallet"}
-tari_crypto = { git = "ssh://git@github.com/tari-project/tari-crypto.git", branch = "main" }
+tari_crypto = { git = "ssh://git@github.com/tari-project/tari-crypto.git", branch = "main" } #switch back to official after merge
 tari_comms = { path = "../../comms"}
 
 chrono = "0.4.6"

applications/tari_app_grpc/proto/types.proto

@@ -102,7 +102,7 @@ message HistoricalBlock {
 }
 
 
-// The NewBlockHeaderTemplate is used for the construction of a new mineable block. It contains all the metadata for the block that the Base Node is able to complete on behalf of a Miner.
+// The NewBlockHeaderTemplate is used for the construction of a new mine-able block. It contains all the metadata for the block that the Base Node is able to complete on behalf of a Miner.
 message NewBlockHeaderTemplate {
     // Version of the block
     uint32 version = 1;
@@ -167,8 +167,8 @@ message TransactionInput {
     // The block height that the UTXO was mined
     uint64 height = 6;
     // A signature with k_s, signing the script, input data, and mined height
-    Signature script_signature = 7;
-    // The offset pubkey, K_O
+    ComSignature script_signature = 7;
+    // The offset public key, K_O
     bytes script_offset_public_key = 8;
 }
 
@@ -186,7 +186,7 @@ message TransactionOutput {
     bytes hash = 4;
     // Tari script serialised script
     bytes script = 5;
-    // Tari script offset pubkey, K_O
+    // Tari script offset public key, K_O
     bytes script_offset_public_key = 6;
     // UTXO signature with the script offset private key, k_O
     Signature sender_metadata_signature = 7;
@@ -227,6 +227,14 @@ message Signature {
     bytes signature = 2;
 }
 
+// Define the explicit ComSignature implementation for the Tari base layer. A different signature scheme can be
+// employed by redefining this type.
+message ComSignature {
+    bytes public_nonce_commitment = 1;
+    bytes signature_u = 2;
+    bytes signature_v = 3;
+}
+
 /// Consensus Constants response
 message ConsensusConstants {
     /// The min height maturity a coinbase utxo must have

applications/tari_app_grpc/src/conversions/com_signature.rs

@@ -0,0 +1,42 @@
+// Copyright 2020. The Tari Project
+//
+// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
+// following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+// disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
+// following disclaimer in the documentation and/or other materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
+// products derived from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+// USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+use std::convert::TryFrom;
+use tari_crypto::tari_utilities::ByteArray;
+
+use crate::tari_rpc as grpc;
+use tari_core::transactions::types::{ComSignature, Commitment, PrivateKey};
+
+impl TryFrom<grpc::ComSignature> for ComSignature {
+    type Error = String;
+
+    fn try_from(sig: grpc::ComSignature) -> Result<Self, Self::Error> {
+        let public_nonce = Commitment::from_bytes(&sig.public_nonce_commitment)
+            .map_err(|_| "Could not get public nonce commitment".to_string())?;
+        let signature_u =
+            PrivateKey::from_bytes(&sig.signature_u).map_err(|_| "Could not get partial signature u".to_string())?;
+        let signature_v =
+            PrivateKey::from_bytes(&sig.signature_v).map_err(|_| "Could not get partial signature v".to_string())?;
+
+        Ok(Self::new(public_nonce, signature_u, signature_v))
+    }
+}

applications/tari_app_grpc/src/conversions/mod.rs

@@ -24,6 +24,7 @@ mod aggregate_body;
 mod block;
 mod block_header;
 mod chain_metadata;
+mod com_signature;
 mod consensus_constants;
 mod historical_block;
 mod new_block_template;
@@ -42,6 +43,7 @@ pub use self::{
     block::*,
     block_header::*,
     chain_metadata::*,
+    com_signature::*,
     consensus_constants::*,
     historical_block::*,
     new_block_template::*,

applications/tari_app_grpc/src/conversions/transaction_input.rs

@@ -79,9 +79,10 @@ impl From<TransactionInput> for grpc::TransactionInput {
             script: input.script.as_bytes(),
             input_data: input.input_data.as_bytes(),
             height: input.height,
-            script_signature: Some(grpc::Signature {
-                public_nonce: Vec::from(input.script_signature.get_public_nonce().as_bytes()),
-                signature: Vec::from(input.script_signature.get_signature().as_bytes()),
+            script_signature: Some(grpc::ComSignature {
+                public_nonce_commitment: Vec::from(input.script_signature.public_nonce().as_bytes()),
+                signature_u: Vec::from(input.script_signature.u().as_bytes()),
+                signature_v: Vec::from(input.script_signature.v().as_bytes()),
             }),
             script_offset_public_key: input.script_offset_public_key.as_bytes().to_vec(),
         }

applications/tari_console_wallet/Cargo.toml

@@ -43,4 +43,3 @@ features = ["transactions", "mempool_proto", "base_node_proto"]
 version = "^0.12"
 default-features = false
 features = ["crossterm"]
-

base_layer/core/src/blocks/genesis_block.rs

@@ -49,7 +49,7 @@ pub fn get_mainnet_genesis_block() -> ChainBlock {
 pub fn get_stibbons_genesis_block() -> ChainBlock {
     // lets get the block
     let mut block = get_stibbons_genesis_block_raw();
-    // Lets load in the stibbons faucet tx's
+    // Lets load in the stibbons faucet transactions
     let mut utxos = Vec::new();
     let file = include_str!("faucets/stibbons_faucet.json");
     // last 2 lines are used for the kernel creation
@@ -88,7 +88,7 @@ pub fn get_stibbons_genesis_block() -> ChainBlock {
 pub fn get_weatherwax_genesis_block() -> ChainBlock {
     // lets get the block
     let mut block = get_weatherwax_genesis_block_raw();
-    // Lets load in the weatherwax faucet tx's
+    // Lets load in the weatherwax faucet transactions
     let mut utxos = Vec::new();
     let file = include_str!("faucets/weatherwax_faucet.json");
     // last 2 lines are used for the kernel creation

base_layer/core/src/proto/transaction.proto

@@ -41,7 +41,7 @@ message TransactionInput {
     // The block height that the UTXO was mined
     uint64 height = 5;
     // A signature with k_s, signing the script, input data, and mined height
-    Signature script_signature = 6;
+    ComSignature script_signature = 6;
     // The offset pubkey, K_O
     bytes script_offset_public_key = 7;
 }

base_layer/core/src/proto/types.proto

@@ -19,6 +19,14 @@ message Signature {
     bytes signature = 2;
 }
 
+// Define the explicit ComSignature implementation for the Tari base layer. A different signature scheme can be
+// employed by redefining this type.
+message ComSignature {
+    bytes public_nonce_commitment = 1;
+    bytes signature_u = 2;
+    bytes signature_v = 3;
+}
+
 // BlindingFactor wrapper
 message BlindingFactor {
     bytes data = 1;

base_layer/core/src/proto/types_impls.rs

@@ -21,7 +21,15 @@
 // USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 use super::types as proto;
-use crate::transactions::types::{BlindingFactor, Commitment, HashOutput, PrivateKey, PublicKey, Signature};
+use crate::transactions::types::{
+    BlindingFactor,
+    ComSignature,
+    Commitment,
+    HashOutput,
+    PrivateKey,
+    PublicKey,
+    Signature,
+};
 use std::convert::TryFrom;
 use tari_crypto::tari_utilities::{ByteArray, ByteArrayError};
 
@@ -65,6 +73,30 @@ impl From<Signature> for proto::Signature {
     }
 }
 
+//---------------------------------- ComSignature --------------------------------------------//
+
+impl TryFrom<proto::ComSignature> for ComSignature {
+    type Error = ByteArrayError;
+
+    fn try_from(sig: proto::ComSignature) -> Result<Self, Self::Error> {
+        let public_nonce = Commitment::from_bytes(&sig.public_nonce_commitment)?;
+        let signature_u = PrivateKey::from_bytes(&sig.signature_u)?;
+        let signature_v = PrivateKey::from_bytes(&sig.signature_v)?;
+
+        Ok(Self::new(public_nonce, signature_u, signature_v))
+    }
+}
+
+impl From<ComSignature> for proto::ComSignature {
+    fn from(sig: ComSignature) -> Self {
+        Self {
+            public_nonce_commitment: sig.public_nonce().to_vec(),
+            signature_u: sig.u().to_vec(),
+            signature_v: sig.v().to_vec(),
+        }
+    }
+}
+
 //---------------------------------- HashOutput --------------------------------------------//
 
 impl From<proto::HashOutput> for HashOutput {

base_layer/core/src/transactions/aggregated_body.rs

@@ -318,7 +318,7 @@ impl AggregateBody {
 
         self.validate_range_proofs(&factories.range_proof)?;
         self.validate_sender_signatures()?;
-        self.validate_script_offset(script_offset_g)
+        self.validate_script_offset(script_offset_g, &factories.commitment)
     }
 
     pub fn dissolve(self) -> (Vec<TransactionInput>, Vec<TransactionOutput>, Vec<TransactionKernel>) {
@@ -378,12 +378,16 @@ impl AggregateBody {
     }
 
     /// this will validate the script offset of the aggregate body.
-    fn validate_script_offset(&self, script_offset: PublicKey) -> Result<(), TransactionError> {
+    fn validate_script_offset(
+        &self,
+        script_offset: PublicKey,
+        factory: &CommitmentFactory,
+    ) -> Result<(), TransactionError> {
         trace!(target: LOG_TARGET, "Checking script offset");
         // lets count up the input script public keys
         let mut input_keys = PublicKey::default();
         for input in &self.inputs {
-            input_keys = input_keys + input.run_and_verify_script()?;
+            input_keys = input_keys + input.run_and_verify_script(factory)?;
         }
 
         // Now lets gather the output public keys and hashes.

base_layer/core/src/transactions/transaction.rs

@@ -30,6 +30,7 @@ use crate::transactions::{
     types::{
         BlindingFactor,
         Challenge,
+        ComSignature,
         Commitment,
         CommitmentFactory,
         CryptoFactories,
@@ -244,18 +245,27 @@ impl UnblindedOutput {
     /// Commits an UnblindedOutput into a Transaction input
     pub fn as_transaction_input(&self, factory: &CommitmentFactory) -> Result<TransactionInput, TransactionError> {
         let commitment = factory.commit(&self.spending_key, &self.value.into());
-        let script_nonce = PrivateKey::random(&mut OsRng);
-        let public_script_nonce = PublicKey::from_secret_key(&script_nonce);
+        let script_nonce_a = PrivateKey::random(&mut OsRng);
+        let script_nonce_b = PrivateKey::random(&mut OsRng);
+        let nonce_commitment = factory.commit(&script_nonce_b, &script_nonce_a);
+
         let e = Challenge::new()
-            .chain(public_script_nonce.as_bytes())
+            .chain(nonce_commitment.as_bytes())
             .chain(self.script.as_bytes().as_slice())
             .chain(self.input_data.as_bytes().as_slice())
-            //.chain(&self.height.to_le_bytes()) //TODO decide if the height should remain in this signature
+            .chain(PublicKey::from_secret_key(&self.script_private_key).as_bytes())
+            .chain(commitment.as_bytes())
             .result()
             .to_vec();
-
-        let script_signature = Signature::sign(self.script_private_key.clone(), script_nonce, &e)
-            .map_err(|_| TransactionError::InvalidSignatureError("Generating script signature".to_string()))?;
+        let script_signature = ComSignature::sign(
+            self.value.into(),
+            self.script_private_key.clone() + self.spending_key.clone(),
+            script_nonce_a,
+            script_nonce_b,
+            &e,
+            factory,
+        )
+        .map_err(|_| TransactionError::InvalidSignatureError("Generating script signature".to_string()))?;
 
         Ok(TransactionInput {
             features: self.features.clone(),
@@ -373,7 +383,7 @@ pub struct TransactionInput {
     /// The block height that the UTXO was mined
     pub height: u64,
     /// A signature with k_s, signing the script, input data, and mined height
-    pub script_signature: Signature,
+    pub script_signature: ComSignature,
     /// The offset pubkey, K_O
     pub script_offset_public_key: PublicKey,
 }
@@ -387,7 +397,7 @@ impl TransactionInput {
         script: TariScript,
         input_data: ExecutionStack,
         height: u64,
-        script_signature: Signature,
+        script_signature: ComSignature,
         script_offset_public_key: PublicKey,
     ) -> TransactionInput {
         TransactionInput {
@@ -428,16 +438,24 @@ impl TransactionInput {
         }
     }
 
-    pub fn validate_script_signature(&self, key: &PublicKey) -> Result<(), TransactionError> {
-        let r = self.script_signature.get_public_nonce();
-        let m = HashDigest::new()
-            .chain(r.as_bytes())
-            .chain(self.script.as_bytes())
-            .chain(self.input_data.as_bytes())
-            //.chain(self.height.to_le_bytes()) //TODO decide if the height should remain in the script signature
+    pub fn validate_script_signature(
+        &self,
+        public_script_key: &PublicKey,
+        factory: &CommitmentFactory,
+    ) -> Result<(), TransactionError> {
+        let nonce_commitment = self.script_signature.public_nonce();
+        let m = Challenge::new()
+            .chain(nonce_commitment.as_bytes())
+            .chain(self.script.as_bytes().as_slice())
+            .chain(self.input_data.as_bytes().as_slice())
+            .chain(public_script_key.as_bytes())
+            .chain(self.commitment.as_bytes())
             .result()
             .to_vec();
-        if self.script_signature.verify_challenge(key, &m) {
+        if self
+            .script_signature
+            .verify_challenge(&(&self.commitment + public_script_key), &m, factory)
+        {
             Ok(())
         } else {
             Err(TransactionError::InvalidSignatureError(
@@ -448,9 +466,9 @@ impl TransactionInput {
 
     /// This will run the script and verify the script signature. If its valid, it will return the resulting public key
     /// from the script.
-    pub fn run_and_verify_script(&self) -> Result<PublicKey, TransactionError> {
+    pub fn run_and_verify_script(&self, factory: &CommitmentFactory) -> Result<PublicKey, TransactionError> {
         let key = self.run_script()?;
-        self.validate_script_signature(&key)?;
+        self.validate_script_signature(&key, factory)?;
         Ok(key)
     }
 }
@@ -1316,7 +1334,7 @@ mod test {
         let script = TariScript::default();
         let input_data = ExecutionStack::default();
         let height = 0;
-        let script_signature = Signature::default();
+        let script_signature = ComSignature::default();
         let offset_pub_key = PublicKey::default();
         let mut input = TransactionInput::new(
             OutputFeatures::default(),

base_layer/core/src/transactions/types.rs

@@ -27,6 +27,7 @@ use tari_crypto::{
     ristretto::{
         dalek_range_proof::DalekRangeProofService,
         pedersen::{PedersenCommitment, PedersenCommitmentFactory},
+        RistrettoComSig,
         RistrettoPublicKey,
         RistrettoSchnorr,
         RistrettoSecretKey,
@@ -36,6 +37,8 @@ use tari_crypto::{
 /// Define the explicit Signature implementation for the Tari base layer. A different signature scheme can be
 /// employed by redefining this type.
 pub type Signature = RistrettoSchnorr;
+/// Define the explicit Commitment Signature implementation for the Tari base layer.
+pub type ComSignature = RistrettoComSig;
 
 /// Define the explicit Commitment implementation for the Tari base layer.
 pub type Commitment = PedersenCommitment;