From fb9ee4f66a562c829e2a4c18951b3d77e6651e32 Mon Sep 17 00:00:00 2001
From: Tom French <15848336+TomAFrench@users.noreply.github.com>
Date: Tue, 19 Sep 2023 15:21:14 +0100
Subject: [PATCH] chore: encapsulate abstraction leaks from `bb` into new crate
 (#2747)

---
 Cargo.lock                                    | 49 ++++++++++++-------
 Cargo.toml                                    |  4 +-
 tooling/acvm_backend_barretenberg/.gitignore  |  1 -
 .../CHANGELOG.md                              |  0
 .../Cargo.toml                                |  5 +-
 .../src/cli/contract.rs                       |  0
 .../src/cli/gates.rs                          |  0
 .../src/cli/info.rs                           |  0
 .../src/cli/mod.rs                            |  0
 .../src/cli/prove.rs                          |  0
 .../src/cli/verify.rs                         |  0
 .../src/cli/write_vk.rs                       |  0
 .../src/download.rs                           |  0
 .../src/lib.rs                                |  8 ++-
 .../src/proof_system.rs                       | 43 +++-------------
 .../src/smart_contract.rs                     | 13 +----
 .../test-binaries/mock_backend/Cargo.lock     |  0
 .../test-binaries/mock_backend/Cargo.toml     |  0
 .../mock_backend/src/contract_cmd.rs          |  6 +--
 .../mock_backend/src/gates_cmd.rs             |  0
 .../mock_backend/src/info_cmd.rs              |  0
 .../test-binaries/mock_backend/src/main.rs    |  0
 .../mock_backend/src/prove_cmd.rs             |  0
 .../mock_backend/src/verify_cmd.rs            |  0
 .../mock_backend/src/write_vk_cmd.rs          |  0
 tooling/bb_abstraction_leaks/Cargo.toml       | 17 +++++++
 .../build.rs                                  |  0
 .../src/contract.sol                          |  0
 tooling/bb_abstraction_leaks/src/lib.rs       | 34 +++++++++++++
 tooling/nargo_cli/Cargo.toml                  |  3 +-
 tooling/nargo_cli/src/backends.rs             |  4 +-
 .../src/cli/backend_cmd/install_cmd.rs        |  2 +-
 .../nargo_cli/src/cli/backend_cmd/ls_cmd.rs   |  2 +-
 .../src/cli/backend_cmd/uninstall_cmd.rs      |  2 +-
 .../nargo_cli/src/cli/codegen_verifier_cmd.rs |  8 ++-
 tooling/nargo_cli/src/cli/compile_cmd.rs      |  2 +-
 tooling/nargo_cli/src/cli/info_cmd.rs         |  2 +-
 tooling/nargo_cli/src/errors.rs               |  2 +-
 tooling/nargo_cli/tests/execute.rs            |  5 +-
 39 files changed, 122 insertions(+), 90 deletions(-)
 delete mode 100644 tooling/acvm_backend_barretenberg/.gitignore
 rename tooling/{acvm_backend_barretenberg => backend_interface}/CHANGELOG.md (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/Cargo.toml (78%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/contract.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/gates.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/info.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/mod.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/prove.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/verify.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/cli/write_vk.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/download.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/lib.rs (94%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/proof_system.rs (74%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/src/smart_contract.rs (79%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/Cargo.lock (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/Cargo.toml (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/contract_cmd.rs (72%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/gates_cmd.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/info_cmd.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/main.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/prove_cmd.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/verify_cmd.rs (100%)
 rename tooling/{acvm_backend_barretenberg => backend_interface}/test-binaries/mock_backend/src/write_vk_cmd.rs (100%)
 create mode 100644 tooling/bb_abstraction_leaks/Cargo.toml
 rename tooling/{acvm_backend_barretenberg => bb_abstraction_leaks}/build.rs (100%)
 rename tooling/{acvm_backend_barretenberg => bb_abstraction_leaks}/src/contract.sol (100%)
 create mode 100644 tooling/bb_abstraction_leaks/src/lib.rs

diff --git a/Cargo.lock b/Cargo.lock
index 8cccc14d393..646d422f686 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -46,24 +46,6 @@ dependencies = [
  "thiserror",
 ]
 
-[[package]]
-name = "acvm-backend-barretenberg"
-version = "0.11.0"
-dependencies = [
- "acvm",
- "build-target",
- "const_format",
- "dirs",
- "flate2",
- "reqwest",
- "serde",
- "serde_json",
- "tar",
- "tempfile",
- "test-binary",
- "thiserror",
-]
-
 [[package]]
 name = "acvm_blackbox_solver"
 version = "0.26.1"
@@ -402,6 +384,25 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "backend-interface"
+version = "0.11.0"
+dependencies = [
+ "acvm",
+ "bb_abstraction_leaks",
+ "build-target",
+ "const_format",
+ "dirs",
+ "flate2",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "tar",
+ "tempfile",
+ "test-binary",
+ "thiserror",
+]
+
 [[package]]
 name = "backtrace"
 version = "0.3.68"
@@ -435,6 +436,15 @@ version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8c3c1a368f70d6cf7302d78f8f7093da241fb8e8807c05cc9e51a125895a6d5b"
 
+[[package]]
+name = "bb_abstraction_leaks"
+version = "0.11.0"
+dependencies = [
+ "acvm",
+ "build-target",
+ "const_format",
+]
+
 [[package]]
 name = "bincode"
 version = "1.3.3"
@@ -2186,10 +2196,11 @@ name = "nargo_cli"
 version = "0.12.0"
 dependencies = [
  "acvm",
- "acvm-backend-barretenberg",
  "assert_cmd",
  "assert_fs",
  "async-lsp",
+ "backend-interface",
+ "bb_abstraction_leaks",
  "build-data",
  "clap",
  "color-eyre",
diff --git a/Cargo.toml b/Cargo.toml
index dac1c15e0a5..2879823163e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,8 @@ members = [
     "compiler/utils/arena",
     "compiler/utils/iter-extended",
     # Crates related to tooling built ontop of the Noir compiler
-    "tooling/acvm_backend_barretenberg",
+    "tooling/backend_interface",
+    "tooling/bb_abstraction_leaks",
     "tooling/nargo",
     "tooling/nargo_cli",
     "tooling/nargo_toml",
@@ -41,6 +42,7 @@ nargo_cli = { path = "tooling/nargo_cli" }
 nargo_toml = { path = "tooling/nargo_toml" }
 noir_lsp = { path = "tooling/lsp" }
 noirc_abi = { path = "tooling/noirc_abi" }
+bb_abstraction_leaks = { path = "tooling/bb_abstraction_leaks" }
 noirc_driver = { path = "compiler/noirc_driver" }
 noirc_errors = { path = "compiler/noirc_errors" }
 noirc_evaluator = { path = "compiler/noirc_evaluator" }
diff --git a/tooling/acvm_backend_barretenberg/.gitignore b/tooling/acvm_backend_barretenberg/.gitignore
deleted file mode 100644
index 106a4f552a0..00000000000
--- a/tooling/acvm_backend_barretenberg/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-!src/witness.tr
diff --git a/tooling/acvm_backend_barretenberg/CHANGELOG.md b/tooling/backend_interface/CHANGELOG.md
similarity index 100%
rename from tooling/acvm_backend_barretenberg/CHANGELOG.md
rename to tooling/backend_interface/CHANGELOG.md
diff --git a/tooling/acvm_backend_barretenberg/Cargo.toml b/tooling/backend_interface/Cargo.toml
similarity index 78%
rename from tooling/acvm_backend_barretenberg/Cargo.toml
rename to tooling/backend_interface/Cargo.toml
index a86fa90b0be..127770c5722 100644
--- a/tooling/acvm_backend_barretenberg/Cargo.toml
+++ b/tooling/backend_interface/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
-name = "acvm-backend-barretenberg"
-description = "An ACVM backend which allows proving/verifying ACIR circuits against Aztec Lab's Barretenberg library."
+name = "backend-interface"
+description = "The definition of the backend CLI interface which Nargo uses for proving/verifying ACIR circuits."
 version = "0.11.0"
 authors.workspace = true
 edition.workspace = true
@@ -15,6 +15,7 @@ dirs.workspace = true
 thiserror.workspace = true
 serde.workspace = true
 serde_json.workspace = true
+bb_abstraction_leaks.workspace = true
 
 tempfile = "3.6.0"
 
diff --git a/tooling/acvm_backend_barretenberg/src/cli/contract.rs b/tooling/backend_interface/src/cli/contract.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/contract.rs
rename to tooling/backend_interface/src/cli/contract.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/gates.rs b/tooling/backend_interface/src/cli/gates.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/gates.rs
rename to tooling/backend_interface/src/cli/gates.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/info.rs b/tooling/backend_interface/src/cli/info.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/info.rs
rename to tooling/backend_interface/src/cli/info.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/mod.rs b/tooling/backend_interface/src/cli/mod.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/mod.rs
rename to tooling/backend_interface/src/cli/mod.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/prove.rs b/tooling/backend_interface/src/cli/prove.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/prove.rs
rename to tooling/backend_interface/src/cli/prove.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/verify.rs b/tooling/backend_interface/src/cli/verify.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/verify.rs
rename to tooling/backend_interface/src/cli/verify.rs
diff --git a/tooling/acvm_backend_barretenberg/src/cli/write_vk.rs b/tooling/backend_interface/src/cli/write_vk.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/cli/write_vk.rs
rename to tooling/backend_interface/src/cli/write_vk.rs
diff --git a/tooling/acvm_backend_barretenberg/src/download.rs b/tooling/backend_interface/src/download.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/download.rs
rename to tooling/backend_interface/src/download.rs
diff --git a/tooling/acvm_backend_barretenberg/src/lib.rs b/tooling/backend_interface/src/lib.rs
similarity index 94%
rename from tooling/acvm_backend_barretenberg/src/lib.rs
rename to tooling/backend_interface/src/lib.rs
index b79ca514043..6d18b6b6ead 100644
--- a/tooling/acvm_backend_barretenberg/src/lib.rs
+++ b/tooling/backend_interface/src/lib.rs
@@ -9,10 +9,10 @@ mod proof_system;
 mod smart_contract;
 
 use acvm::acir::circuit::Opcode;
+use bb_abstraction_leaks::ACVM_BACKEND_BARRETENBERG;
 pub use download::download_backend;
 
 const BACKENDS_DIR: &str = ".nargo/backends";
-pub const ACVM_BACKEND_BARRETENBERG: &str = "acvm-backend-barretenberg";
 
 pub fn backends_directory() -> PathBuf {
     let home_directory = dirs::home_dir().unwrap();
@@ -65,6 +65,10 @@ impl Backend {
         Backend { name, binary_path }
     }
 
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
     fn binary_path(&self) -> &PathBuf {
         &self.binary_path
     }
@@ -77,7 +81,7 @@ impl Backend {
             if self.name == ACVM_BACKEND_BARRETENBERG {
                 // If we're trying to use barretenberg, automatically go and install it.
                 let bb_url = std::env::var("BB_BINARY_URL")
-                    .unwrap_or_else(|_| env!("BB_BINARY_URL").to_string());
+                    .unwrap_or_else(|_| bb_abstraction_leaks::BB_DOWNLOAD_URL.to_owned());
                 download_backend(&bb_url, binary_path)?;
                 return Ok(binary_path);
             }
diff --git a/tooling/acvm_backend_barretenberg/src/proof_system.rs b/tooling/backend_interface/src/proof_system.rs
similarity index 74%
rename from tooling/acvm_backend_barretenberg/src/proof_system.rs
rename to tooling/backend_interface/src/proof_system.rs
index b681883fdad..ffdb7531ed1 100644
--- a/tooling/acvm_backend_barretenberg/src/proof_system.rs
+++ b/tooling/backend_interface/src/proof_system.rs
@@ -63,15 +63,10 @@ impl Backend {
         }
         .run(binary_path)?;
 
-        // Barretenberg return the proof prepended with the public inputs.
-        //
-        // This is not how the API expects the proof to be formatted,
-        // so we remove the public inputs from the proof.
-        //
-        // TODO: As noted in the verification procedure, this is an abstraction leak
-        // TODO: and will need modifications to barretenberg
-        let proof =
-            remove_public_inputs(circuit.public_inputs().0.len(), &proof_with_public_inputs);
+        let proof = bb_abstraction_leaks::remove_public_inputs(
+            circuit.public_inputs().0.len(),
+            &proof_with_public_inputs,
+        );
         Ok(proof)
     }
 
@@ -92,12 +87,10 @@ impl Backend {
         let flattened_public_inputs: Vec<FieldElement> =
             public_inputs.into_iter().map(|(_, el)| el).collect();
 
-        // Barretenberg expects the proof to be prepended with the public inputs.
-        //
-        // TODO: This is an abstraction leak and barretenberg's API should accept the public inputs
-        // TODO: separately and then prepend them internally
-        let proof_with_public_inputs =
-            prepend_public_inputs(proof.to_vec(), flattened_public_inputs.to_vec());
+        let proof_with_public_inputs = bb_abstraction_leaks::prepend_public_inputs(
+            proof.to_vec(),
+            flattened_public_inputs.to_vec(),
+        );
 
         // Create a temporary file for the proof
         let proof_path = temp_directory.join("proof").with_extension("proof");
@@ -139,26 +132,6 @@ pub(super) fn write_to_file(bytes: &[u8], path: &Path) -> String {
     }
 }
 
-/// Removes the public inputs which are prepended to a proof by Barretenberg.
-fn remove_public_inputs(num_pub_inputs: usize, proof: &[u8]) -> Vec<u8> {
-    // Barretenberg prepends the public inputs onto the proof so we need to remove
-    // the first `num_pub_inputs` field elements.
-    let num_bytes_to_remove = num_pub_inputs * (FieldElement::max_num_bytes() as usize);
-    proof[num_bytes_to_remove..].to_vec()
-}
-
-/// Prepends a set of public inputs to a proof.
-fn prepend_public_inputs(proof: Vec<u8>, public_inputs: Vec<FieldElement>) -> Vec<u8> {
-    if public_inputs.is_empty() {
-        return proof;
-    }
-
-    let public_inputs_bytes =
-        public_inputs.into_iter().flat_map(|assignment| assignment.to_be_bytes());
-
-    public_inputs_bytes.chain(proof).collect()
-}
-
 // TODO: See nargo/src/artifacts/mod.rs
 // TODO: This method should live in ACVM and be the default method for serializing/deserializing circuits
 pub(super) fn serialize_circuit(circuit: &Circuit) -> Vec<u8> {
diff --git a/tooling/acvm_backend_barretenberg/src/smart_contract.rs b/tooling/backend_interface/src/smart_contract.rs
similarity index 79%
rename from tooling/acvm_backend_barretenberg/src/smart_contract.rs
rename to tooling/backend_interface/src/smart_contract.rs
index e5018c69bd9..5f56557cad4 100644
--- a/tooling/acvm_backend_barretenberg/src/smart_contract.rs
+++ b/tooling/backend_interface/src/smart_contract.rs
@@ -6,9 +6,6 @@ use crate::{
 use acvm::acir::circuit::Circuit;
 use tempfile::tempdir;
 
-/// Embed the Solidity verifier file
-const ULTRA_VERIFIER_CONTRACT: &str = include_str!("contract.sol");
-
 impl Backend {
     pub fn eth_contract(&self, circuit: &Circuit) -> Result<String, BackendError> {
         let binary_path = self.assert_binary_exists()?;
@@ -32,11 +29,7 @@ impl Backend {
         }
         .run(binary_path)?;
 
-        let verification_key_library =
-            ContractCommand { crs_path: self.crs_directory(), vk_path }.run(binary_path)?;
-
-        drop(temp_directory);
-        Ok(format!("{verification_key_library}{ULTRA_VERIFIER_CONTRACT}"))
+        ContractCommand { crs_path: self.crs_directory(), vk_path }.run(binary_path)
     }
 }
 
@@ -67,9 +60,7 @@ mod tests {
 
         let contract = get_mock_backend()?.eth_contract(&circuit)?;
 
-        assert!(contract.contains("contract BaseUltraVerifier"));
-        assert!(contract.contains("contract UltraVerifier"));
-        assert!(contract.contains("library UltraVerificationKey"));
+        assert!(contract.contains("contract VerifierContract"));
 
         Ok(())
     }
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/Cargo.lock b/tooling/backend_interface/test-binaries/mock_backend/Cargo.lock
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/Cargo.lock
rename to tooling/backend_interface/test-binaries/mock_backend/Cargo.lock
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/Cargo.toml b/tooling/backend_interface/test-binaries/mock_backend/Cargo.toml
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/Cargo.toml
rename to tooling/backend_interface/test-binaries/mock_backend/Cargo.toml
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/contract_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/contract_cmd.rs
similarity index 72%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/contract_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/contract_cmd.rs
index fb8daf784f1..7ee41121d61 100644
--- a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/contract_cmd.rs
+++ b/tooling/backend_interface/test-binaries/mock_backend/src/contract_cmd.rs
@@ -17,9 +17,5 @@ pub(crate) struct ContractCommand {
 pub(crate) fn run(args: ContractCommand) {
     assert!(args.vk_path.is_file(), "Could not find vk file at provided path");
 
-    std::io::stdout()
-        .write_all(
-            b"contract BaseUltraVerifier contract UltraVerifier library UltraVerificationKey",
-        )
-        .unwrap();
+    std::io::stdout().write_all(b"contract VerifierContract {}").unwrap();
 }
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/gates_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/gates_cmd.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/gates_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/gates_cmd.rs
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/info_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/info_cmd.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/info_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/info_cmd.rs
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/main.rs b/tooling/backend_interface/test-binaries/mock_backend/src/main.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/main.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/main.rs
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/prove_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/prove_cmd.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/prove_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/prove_cmd.rs
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/verify_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/verify_cmd.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/verify_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/verify_cmd.rs
diff --git a/tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/write_vk_cmd.rs b/tooling/backend_interface/test-binaries/mock_backend/src/write_vk_cmd.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/test-binaries/mock_backend/src/write_vk_cmd.rs
rename to tooling/backend_interface/test-binaries/mock_backend/src/write_vk_cmd.rs
diff --git a/tooling/bb_abstraction_leaks/Cargo.toml b/tooling/bb_abstraction_leaks/Cargo.toml
new file mode 100644
index 00000000000..86164ba11c3
--- /dev/null
+++ b/tooling/bb_abstraction_leaks/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "bb_abstraction_leaks"
+description = "A crate which encapsulates knowledge about Barretenberg which is currently leaking into Nargo"
+version = "0.11.0"
+authors.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+acvm.workspace = true
+
+[build-dependencies]
+build-target = "0.4.0"
+const_format = "0.2.30"
diff --git a/tooling/acvm_backend_barretenberg/build.rs b/tooling/bb_abstraction_leaks/build.rs
similarity index 100%
rename from tooling/acvm_backend_barretenberg/build.rs
rename to tooling/bb_abstraction_leaks/build.rs
diff --git a/tooling/acvm_backend_barretenberg/src/contract.sol b/tooling/bb_abstraction_leaks/src/contract.sol
similarity index 100%
rename from tooling/acvm_backend_barretenberg/src/contract.sol
rename to tooling/bb_abstraction_leaks/src/contract.sol
diff --git a/tooling/bb_abstraction_leaks/src/lib.rs b/tooling/bb_abstraction_leaks/src/lib.rs
new file mode 100644
index 00000000000..799e14c36f0
--- /dev/null
+++ b/tooling/bb_abstraction_leaks/src/lib.rs
@@ -0,0 +1,34 @@
+#![warn(unused_crate_dependencies, unused_extern_crates)]
+#![warn(unreachable_pub)]
+
+use acvm::FieldElement;
+
+pub const ACVM_BACKEND_BARRETENBERG: &str = "acvm-backend-barretenberg";
+pub const BB_DOWNLOAD_URL: &str = env!("BB_BINARY_URL");
+
+/// Embed the Solidity verifier file
+const ULTRA_VERIFIER_CONTRACT: &str = include_str!("contract.sol");
+
+pub fn complete_barretenberg_verifier_contract(contract: String) -> String {
+    format!("{contract}{ULTRA_VERIFIER_CONTRACT}")
+}
+
+/// Removes the public inputs which are prepended to a proof by Barretenberg.
+pub fn remove_public_inputs(num_pub_inputs: usize, proof: &[u8]) -> Vec<u8> {
+    // Barretenberg prepends the public inputs onto the proof so we need to remove
+    // the first `num_pub_inputs` field elements.
+    let num_bytes_to_remove = num_pub_inputs * (FieldElement::max_num_bytes() as usize);
+    proof[num_bytes_to_remove..].to_vec()
+}
+
+/// Prepends a set of public inputs to a proof.
+pub fn prepend_public_inputs(proof: Vec<u8>, public_inputs: Vec<FieldElement>) -> Vec<u8> {
+    if public_inputs.is_empty() {
+        return proof;
+    }
+
+    let public_inputs_bytes =
+        public_inputs.into_iter().flat_map(|assignment| assignment.to_be_bytes());
+
+    public_inputs_bytes.chain(proof).collect()
+}
diff --git a/tooling/nargo_cli/Cargo.toml b/tooling/nargo_cli/Cargo.toml
index 0b85c66b6fa..e14d43b9fc3 100644
--- a/tooling/nargo_cli/Cargo.toml
+++ b/tooling/nargo_cli/Cargo.toml
@@ -50,7 +50,8 @@ color-eyre = "0.6.2"
 tokio = { version = "1.0", features = ["io-std"] }
 
 # Backends
-acvm-backend-barretenberg = { path = "../acvm_backend_barretenberg" }
+backend-interface = { path = "../backend_interface" }
+bb_abstraction_leaks.workspace = true
 
 [target.'cfg(not(unix))'.dependencies]
 tokio-util = { version = "0.7.8", features = ["compat"] }
diff --git a/tooling/nargo_cli/src/backends.rs b/tooling/nargo_cli/src/backends.rs
index 8ca8305e180..8b1da2cd118 100644
--- a/tooling/nargo_cli/src/backends.rs
+++ b/tooling/nargo_cli/src/backends.rs
@@ -1,7 +1,7 @@
 use std::path::PathBuf;
 
-use acvm_backend_barretenberg::backends_directory;
-pub(crate) use acvm_backend_barretenberg::Backend;
+use backend_interface::backends_directory;
+pub(crate) use backend_interface::Backend;
 
 fn active_backend_file_path() -> PathBuf {
     backends_directory().join(".selected_backend")
diff --git a/tooling/nargo_cli/src/cli/backend_cmd/install_cmd.rs b/tooling/nargo_cli/src/cli/backend_cmd/install_cmd.rs
index 99bca29d3b7..974db9ff7f5 100644
--- a/tooling/nargo_cli/src/cli/backend_cmd/install_cmd.rs
+++ b/tooling/nargo_cli/src/cli/backend_cmd/install_cmd.rs
@@ -1,6 +1,6 @@
 use clap::Args;
 
-use acvm_backend_barretenberg::{backends_directory, download_backend};
+use backend_interface::{backends_directory, download_backend};
 
 use crate::errors::{BackendError, CliError};
 
diff --git a/tooling/nargo_cli/src/cli/backend_cmd/ls_cmd.rs b/tooling/nargo_cli/src/cli/backend_cmd/ls_cmd.rs
index 38ff6d3b744..da37b104d65 100644
--- a/tooling/nargo_cli/src/cli/backend_cmd/ls_cmd.rs
+++ b/tooling/nargo_cli/src/cli/backend_cmd/ls_cmd.rs
@@ -1,4 +1,4 @@
-use acvm_backend_barretenberg::backends_directory;
+use backend_interface::backends_directory;
 use clap::Args;
 
 use crate::errors::CliError;
diff --git a/tooling/nargo_cli/src/cli/backend_cmd/uninstall_cmd.rs b/tooling/nargo_cli/src/cli/backend_cmd/uninstall_cmd.rs
index 469f099de28..7497f1bc2f6 100644
--- a/tooling/nargo_cli/src/cli/backend_cmd/uninstall_cmd.rs
+++ b/tooling/nargo_cli/src/cli/backend_cmd/uninstall_cmd.rs
@@ -1,6 +1,6 @@
 use clap::Args;
 
-use acvm_backend_barretenberg::backends_directory;
+use backend_interface::backends_directory;
 
 use crate::{
     backends::{
diff --git a/tooling/nargo_cli/src/cli/codegen_verifier_cmd.rs b/tooling/nargo_cli/src/cli/codegen_verifier_cmd.rs
index 5ad451f6a6a..30b865063d3 100644
--- a/tooling/nargo_cli/src/cli/codegen_verifier_cmd.rs
+++ b/tooling/nargo_cli/src/cli/codegen_verifier_cmd.rs
@@ -10,6 +10,7 @@ use crate::errors::CliError;
 
 use acvm::acir::circuit::Opcode;
 use acvm::Language;
+use bb_abstraction_leaks::ACVM_BACKEND_BARRETENBERG;
 use clap::Args;
 use nargo::artifacts::program::PreprocessedProgram;
 use nargo::package::Package;
@@ -91,7 +92,12 @@ fn smart_contract_for_package(
         }
     };
 
-    let smart_contract_string = backend.eth_contract(&preprocessed_program.bytecode)?;
+    let mut smart_contract_string = backend.eth_contract(&preprocessed_program.bytecode)?;
+
+    if backend.name() == ACVM_BACKEND_BARRETENBERG {
+        smart_contract_string =
+            bb_abstraction_leaks::complete_barretenberg_verifier_contract(smart_contract_string);
+    }
 
     Ok(smart_contract_string)
 }
diff --git a/tooling/nargo_cli/src/cli/compile_cmd.rs b/tooling/nargo_cli/src/cli/compile_cmd.rs
index fb8a91c8811..3ccd99558a7 100644
--- a/tooling/nargo_cli/src/cli/compile_cmd.rs
+++ b/tooling/nargo_cli/src/cli/compile_cmd.rs
@@ -2,7 +2,7 @@ use std::path::Path;
 
 use acvm::acir::circuit::Opcode;
 use acvm::Language;
-use acvm_backend_barretenberg::BackendOpcodeSupport;
+use backend_interface::BackendOpcodeSupport;
 use fm::FileManager;
 use iter_extended::vecmap;
 use nargo::artifacts::contract::PreprocessedContract;
diff --git a/tooling/nargo_cli/src/cli/info_cmd.rs b/tooling/nargo_cli/src/cli/info_cmd.rs
index 39708a26bd8..8018308ee54 100644
--- a/tooling/nargo_cli/src/cli/info_cmd.rs
+++ b/tooling/nargo_cli/src/cli/info_cmd.rs
@@ -1,5 +1,5 @@
 use acvm::Language;
-use acvm_backend_barretenberg::BackendError;
+use backend_interface::BackendError;
 use clap::Args;
 use iter_extended::vecmap;
 use nargo::package::Package;
diff --git a/tooling/nargo_cli/src/errors.rs b/tooling/nargo_cli/src/errors.rs
index 205f68f624e..49fa02d281d 100644
--- a/tooling/nargo_cli/src/errors.rs
+++ b/tooling/nargo_cli/src/errors.rs
@@ -70,7 +70,7 @@ pub(crate) enum CliError {
 
     /// Error related to communication with backend.
     #[error(transparent)]
-    BackendCommunicationError(#[from] acvm_backend_barretenberg::BackendError),
+    BackendCommunicationError(#[from] backend_interface::BackendError),
 }
 
 #[derive(Debug, thiserror::Error)]
diff --git a/tooling/nargo_cli/tests/execute.rs b/tooling/nargo_cli/tests/execute.rs
index 9e02951573d..e2bef43b571 100644
--- a/tooling/nargo_cli/tests/execute.rs
+++ b/tooling/nargo_cli/tests/execute.rs
@@ -12,10 +12,7 @@ mod tests {
 
     use super::*;
 
-    test_binary::build_test_binary_once!(
-        mock_backend,
-        "../acvm_backend_barretenberg/test-binaries"
-    );
+    test_binary::build_test_binary_once!(mock_backend, "../backend_interface/test-binaries");
 
     // include tests generated by `build.rs`
     include!(concat!(env!("OUT_DIR"), "/execute.rs"));