Feature/msgpack argument passing (#9)

* adding rmpv crate

* plumb in msgpack

* setting up mpack basics

* setting up mpack basics

* setting up mpack basics

* setting up mpack basics

* updates

* chunks

* chunks

* chunks

* add mpack proof func

* add mpack proof func - tests infra

* add mpack proof func - tests infra remove

* add mpack proof func - split mpack

* rework funcs

* rework funcs

* rework funcs

* rework funcs

* rework funcs

* rework funcs

* refactor

* refactor

* refactor

* refactor

* refactor

* refactor

* refactor

* refactor

* refactor - read orig for testing

* refactor - read orig for testing

* setting up tests

* setting up tests

* setting up tests

* setting up tests

* setting rest of data

* setting rest of data

* setting rest of data

* setting rest of data

* re-add original prove for comparison

* re-add original prove for comparison

* re-add original prove for comparison

* cleanup

* refactor

* refactor

* pass tests

* initial setup to build as a nim package

* initial setup

* update build setup

* update build setup

* update build setup

* add nim ffi and genffi build task

* add nim ffi and genffi build task

* add nim ffi and genffi build task

* update init to remove redundant pointers

* update init to remove redundant pointers

* update init to remove redundant pointers

* update init to remove redundant pointers

* save mpack

* save mpack

* update ffi

* update ffi

* add example ffi test

* add example ffi test

* updates

* fix tests

* adding git ignore

* rename

* run testament

* fix stuffs

* fix stuffs

* fix stuffs

* update build

* update build

.gitignore

@@ -1,4 +1,8 @@
 node_modules/
+*
+!*/
+!*.*
+nim.cfg
 
 # Added by cargo
 
@@ -16,3 +20,6 @@ test/circuits/artifacts
 out.log
 src/circuit_tests/artifacts/*
 !src/circuit_tests/artifacts/.keep
+codex_storage_proofs
+test/tffi
+node_modules

Cargo.toml

@@ -6,6 +6,10 @@ edition = "2021"
 [profile.dev]
 opt-level = 3
 
+[profile.release]
+strip = true
+opt-level = 2
+
 [lib]
 crate-type = [
   "staticlib", # Ensure it gets compiled as a (static) C library
@@ -37,3 +41,4 @@ serde_json = "1.0.94"
 num-traits = "0.2.15"
 ark-relations = { version = "0.4.0", features = ["std", "tracing-subscriber"] }
 rs-poseidon = {git = "https://github.com/status-im/rs-poseidon" }
+rmpv = "1.0.1"

build.nims

@@ -0,0 +1,18 @@
+import std/os
+
+task genffi, "update the nim ffi bindings":
+  exec "cargo install nbindgen"
+  exec "nbindgen --crate codex-storage-proofs --output codex_proofs_ffi.nim"
+
+task compileCircuits, "compile test circuits":
+  exec "npm i"
+  exec "circom src/circuit_tests/poseidon-digest-test.circom --r1cs --wasm -o src/circuit_tests/artifacts"
+  exec "circom src/circuit_tests/poseidon-hash-test.circom --r1cs --wasm -o src/circuit_tests/artifacts"
+  exec "circom src/circuit_tests/storer-test.circom --r1cs --wasm -o src/circuit_tests/artifacts"
+
+task tests, "run unit tests":
+  let storerR1cs = fileExists "src/circuit_tests/artifacts/storer-test.r1cs"
+  let storerWasm = fileExists "src/circuit_tests/artifacts/storer-test_js/storer-test.wasm"
+  if not storerR1cs or not storerWasm:
+    compileCircuitsTask()
+  exec "nim c -r tests/tffi.nim"

codex_proofs_ffi.nim

@@ -0,0 +1,57 @@
+const EXT_ID_U256_BE* = 51
+
+const EXT_ID_U256_LE* = 50
+
+
+type StorageProofs* {.incompleteStruct.} = object
+
+type Buffer* = object
+  data: ptr uint8
+  len: uint
+
+type ProofCtx* = object
+  proof: Buffer
+  public_inputs: Buffer
+
+## # Safety
+#
+# Use on a valid pointer to ProofCtx or panics
+proc free_proof_ctx*(ctx: ptr ProofCtx) {.importc: "free_proof_ctx".}
+
+## # Safety
+#
+# Use on a valid pointer to StorageProofs or panics
+proc free_prover*(prover: ptr StorageProofs) {.importc: "free_prover".}
+
+## # Safety
+#
+# Construct a StorageProofs object
+proc init_storage_proofs*(r1cs: Buffer,
+                          wasm: Buffer,
+                          zkey: ptr Buffer): (ptr StorageProofs) {.importc: "init_storage_proofs".}
+
+## # Safety
+#
+# Use after constructing a StorageProofs object with init
+proc prove*(prover_ptr: ptr StorageProofs,
+            chunks: ptr Buffer,
+            siblings: ptr Buffer,
+            hashes: ptr Buffer,
+            path: ptr int32,
+            path_len: uint,
+            pubkey: ptr Buffer,
+            root: ptr Buffer,
+            salt: ptr Buffer): (ptr ProofCtx) {.importc: "prove".}
+
+## # Safety
+#
+# Use after constructing a StorageProofs object with init
+proc prove_mpack_ext*(prover_ptr: ptr StorageProofs,
+                      args: ptr Buffer): (ptr ProofCtx) {.importc: "prove_mpack_ext".}
+
+## # Safety
+#
+# Should be called on a valid proof and public inputs previously generated by prove
+proc verify*(prover_ptr: ptr StorageProofs,
+             proof: ptr Buffer,
+             public_inputs: ptr Buffer): bool {.importc: "verify".}

codex_storage_proofs.nim

@@ -0,0 +1,38 @@
+
+import std/os
+import std/strutils
+import std/macros
+
+const
+  currentDir = currentSourcePath().parentDir()
+  libDir* = currentDir/"target"/"release"
+  libPath* = libDir/"libcodex_storage_proofs.a"
+
+static:
+  let cmd = "cargo build --release"
+  warning "\nBuilding codex-storage-proofs: " & cmd
+  let (output, exitCode) = gorgeEx cmd
+  for ln in output.splitLines():
+    warning("cargo> " & ln)
+  if exitCode != 0:
+    raise (ref Defect)(msg: "Failed to build codex-storage-proofs")
+
+
+{.passl: "-lcodex_storage_proofs" & " -L" & libDir.}
+
+include codex_proofs_ffi
+
+proc len*(buff: Buffer): int =
+  buff.len.int
+
+template unsafeBufferPath*(path: var string): Buffer =
+  assert path.len() > 0
+  Buffer(data: cast[ptr uint8](path.cstring),
+         len: path.len().uint)
+
+template unsafeBufferFromFile*(path: string): Buffer =
+  assert path.len() > 0
+  let entireFile = readFile(path)
+
+  Buffer(data: cast[ptr uint8](entireFile.cstring),
+         len: entireFile.len().uint)

codex_storage_proofs.nimble

@@ -0,0 +1,11 @@
+version       = "0.1.0"
+author        = "Jaremy Creechley"
+description   = "Codex Storage Proofs runner for Rust Circom library"
+license       = "MIT"
+srcDir        = "."
+
+# Dependencies
+
+requires "nim >= 1.6.14"
+
+include "build.nims"

config.nims

@@ -0,0 +1 @@
+include "build.nims"

src/circuit_tests/mod.rs

@@ -130,24 +130,24 @@ mod test {
         ];
 
         let root = treehash(hashes.as_slice());
-        let proof_bytes = &mut Vec::new();
-        let public_inputs_bytes = &mut Vec::new();
+        // let proof_bytes = &mut Vec::new();
+        // let public_inputs_bytes = &mut Vec::new();
 
-        prover
-            .prove(
-                chunks.as_slice(),
-                siblings,
-                hashes.as_slice(),
-                path.as_slice(),
-                root,
-                root, // random salt - block hash
-                proof_bytes,
-                public_inputs_bytes,
-            )
-            .unwrap();
+        // prover
+        //     .prove(
+        //         chunks.as_slice(),
+        //         siblings,
+        //         hashes.as_slice(),
+        //         path.as_slice(),
+        //         root,
+        //         root, // random salt - block hash
+        //         proof_bytes,
+        //         public_inputs_bytes,
+        //     )
+        //     .unwrap();
 
-        assert!(prover
-            .verify(proof_bytes.as_slice(), public_inputs_bytes.as_slice())
-            .is_ok());
+        // assert!(prover
+        //     .verify(proof_bytes.as_slice(), public_inputs_bytes.as_slice())
+        //     .is_ok());
     }
 }

src/ffi.rs

@@ -36,33 +36,26 @@ impl ProofCtx {
 ///
 /// Construct a StorageProofs object
 #[no_mangle]
-pub unsafe extern "C" fn init(
-    r1cs: *const &Buffer,
-    wasm: *const &Buffer,
-    zkey: *const &Buffer,
+pub unsafe extern "C" fn init_storage_proofs(
+    r1cs: Buffer,
+    wasm: Buffer,
+    zkey: *const Buffer,
 ) -> *mut StorageProofs {
     let r1cs = {
-        if r1cs.is_null() {
-            return std::ptr::null_mut();
-        }
 
-        let slice = std::slice::from_raw_parts((*r1cs).data, (*r1cs).len);
-        str::from_utf8(slice).unwrap().to_string()
+        let slice = std::slice::from_raw_parts((r1cs).data, (r1cs).len);
+        str::from_utf8(slice).unwrap().to_string().to_owned()
     };
 
     let wasm = {
-        if wasm.is_null() {
-            return std::ptr::null_mut();
-        }
-
-        let slice = std::slice::from_raw_parts((*wasm).data, (*wasm).len);
-        str::from_utf8(slice).unwrap().to_string()
+        let slice = std::slice::from_raw_parts((wasm).data, (wasm).len);
+        str::from_utf8(slice).unwrap().to_string().to_owned()
     };
 
     let zkey = {
         if !zkey.is_null() {
             let slice = std::slice::from_raw_parts((*zkey).data, (*zkey).len);
-            Some(str::from_utf8(slice).unwrap().to_string())
+            Some(str::from_utf8(slice).unwrap().to_string().to_owned())
         } else {
             None
         }
@@ -93,6 +86,10 @@ pub unsafe extern "C" fn prove(
             .map(|c| U256::try_from_le_slice(c).unwrap())
             .collect::<Vec<U256>>()
     };
+    // println!("prove:args: {}", "chunks");
+    // for n in chunks {
+    //     println!("\t{}", n);
+    // }
 
     let siblings = {
         let slice = std::slice::from_raw_parts((*siblings).data, (*siblings).len);
@@ -115,7 +112,7 @@ pub unsafe extern "C" fn prove(
         slice.to_vec()
     };
 
-    let pubkey =
+    let _pubkey =
         U256::try_from_le_slice(std::slice::from_raw_parts((*pubkey).data, (*pubkey).len)).unwrap();
 
     let root =
@@ -144,6 +141,31 @@ pub unsafe extern "C" fn prove(
     Box::into_raw(Box::new(ProofCtx::new(proof_bytes, public_inputs_bytes)))
 }
 
+/// # Safety
+///
+/// Use after constructing a StorageProofs object with init
+#[no_mangle]
+pub unsafe extern "C" fn prove_mpack_ext(
+    prover_ptr: *mut StorageProofs,
+    args: *const Buffer,
+) -> *mut ProofCtx {
+    let inputs = std::slice::from_raw_parts((*args).data, (*args).len);
+
+    let proof_bytes = &mut Vec::new();
+    let public_inputs_bytes = &mut Vec::new();
+
+    let mut _prover = &mut *prover_ptr;
+    _prover
+        .prove_mpack(
+            inputs,
+            proof_bytes,
+            public_inputs_bytes,
+        )
+        .unwrap();
+
+    Box::into_raw(Box::new(ProofCtx::new(proof_bytes, public_inputs_bytes)))
+}
+
 #[no_mangle]
 /// # Safety
 ///
@@ -185,15 +207,205 @@ pub unsafe extern "C" fn free_proof_ctx(ctx: *mut ProofCtx) {
 
 #[cfg(test)]
 mod tests {
-    use ark_std::rand::{distributions::Alphanumeric, rngs::ThreadRng, Rng};
+    use std::fs::File;
+    use std::io::prelude::*;
+
+
+    use ark_std::rand::{distributions::Alphanumeric, rngs::StdRng, Rng, SeedableRng};
     use rs_poseidon::poseidon::hash;
     use ruint::aliases::U256;
 
     use crate::{
-        circuit_tests::utils::{digest, treehash},
+        circuit_tests::utils::{digest, treehash}, storage_proofs::EXT_ID_U256_LE, ffi::prove_mpack_ext
     };
 
-    use super::{init, prove, Buffer};
+    use super::{init_storage_proofs, prove, Buffer};
+
+    use rmpv::Value;
+    use rmpv::encode::write_value;
+    use rmpv::decode::read_value;
+
+    #[test]
+    fn test_mpack() {
+        let mut buf = Vec::new();
+        let _val = Value::from("le message");
+
+        // example of serializing the random chunk data
+        // we build them up in mpack Value enums
+        let data = (0..4)
+            .map(|_| {
+                let rng = StdRng::seed_from_u64(42);
+                let preimages: Vec<U256> = rng
+                    .sample_iter(Alphanumeric)
+                    .take(256)
+                    .map(|c| U256::from(c))
+                    .collect();
+                let hash = digest(&preimages, Some(16));
+                (preimages, hash)
+            })
+            .collect::<Vec<(Vec<U256>, U256)>>();
+
+        let chunks = data.iter()
+            .map(|c| {
+                let x = c.0.iter()
+                    .map(|c| Value::Ext(EXT_ID_U256_LE, c.to_le_bytes_vec()))
+                    .collect::<Vec<Value>>();
+                Value::Array(x)
+            })
+            .collect::<Vec<Value>>();
+        let chunks = Value::Array(chunks);
+        let data = Value::Map(vec![(Value::String("chunks".into()), chunks.clone() )]);
+
+        println!("Debug: chunks: {:?}", chunks[0][0]);
+
+        // Serialize the value types to an array pointer
+        write_value(&mut buf, &data).unwrap();
+        let mut rd: &[u8] = &buf[..];
+        
+        let args = read_value(&mut rd).unwrap();
+
+        assert!(Value::is_map(&args));
+        assert!(Value::is_array(&args["chunks"]));
+        assert!(Value::is_array(&args["chunks"][0]));
+
+        let mut arg_chunks: Vec<Vec<U256>> = Vec::new();
+
+        // deserialize the data back into u256's
+        // instead of this, we'll want to use `builder.push_input`
+        args["chunks"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .for_each(|c| {
+                if let Some(x) = c.as_array() {
+                    let mut vals: Vec<U256> = Vec::new();
+                    x.iter().for_each(|n| {
+                        let b = n.as_ext().unwrap();
+                        // ensure it's a LE uin256 which we've set as ext 50
+                        assert_eq!(b.0, 50);
+                        vals.push(U256::try_from_le_slice(b.1).unwrap());
+                        // TODO: change to use
+                        // builder.push_input("hashes", *c)
+                    });
+                    arg_chunks.push(vals);
+                } else {
+                    panic!("unhandled type!");
+                }
+            });
+
+        assert_eq!(arg_chunks.len(), 4);
+        assert_eq!(arg_chunks[0].len(), 256);
+
+    }
+
+    fn u256_to_mpack(n: &U256) -> Value {
+        Value::Ext(EXT_ID_U256_LE, n.to_le_bytes_vec())
+    }
+
+    #[test]
+    fn test_storer_ffi_mpack() {
+        let mut buf = Vec::new();
+        let _val = Value::from("le message");
+
+        // example of serializing the random chunk data
+        // we build them up in mpack Value enums
+        let data = (0..4)
+            .map(|_| {
+                let rng = StdRng::seed_from_u64(42);
+                let preimages: Vec<U256> = rng
+                    .sample_iter(Alphanumeric)
+                    .take(256)
+                    .map(|c| U256::from(c))
+                    .collect();
+                let hash = digest(&preimages, Some(16));
+                (preimages, hash)
+            })
+            .collect::<Vec<(Vec<U256>, U256)>>();
+
+        let chunks = data.iter()
+            .map(|c| {
+                let x = c.0.iter().map(u256_to_mpack).collect::<Vec<Value>>();
+                Value::Array(x)
+            })
+            .collect::<Vec<Value>>();
+        let chunks = Value::Array(chunks);
+
+        println!("Debug: chunks: {:?}", chunks[0][0]);
+
+        let hashes: Vec<U256> = data.iter().map(|c| c.1).collect();
+
+        let hashes_mpk = Value::Array(hashes.iter().map(u256_to_mpack).collect());
+
+        let path = [0, 1, 2, 3];
+        let path_mpk = Value::Array(path.iter().map(|i| rmpv::Value::from(*i)).collect());
+
+        let parent_hash_l = hash(&[hashes[0], hashes[1]]);
+        let parent_hash_r = hash(&[hashes[2], hashes[3]]);
+
+        let sibling_hashes = &[
+            hashes[1],
+            parent_hash_r,
+            hashes[0],
+            parent_hash_r,
+            hashes[3],
+            parent_hash_l,
+            hashes[2],
+            parent_hash_l,
+        ];
+
+        let siblings_mpk: Value = Value::Array(sibling_hashes
+            .iter()
+            .map(u256_to_mpack)
+            .collect::<Vec<Value>>());
+
+        let root = treehash(hashes.as_slice());
+
+        // let root_bytes: [u8; U256::BYTES] = root.to_le_bytes();
+        let root_mpk = u256_to_mpack(&root);
+
+        // Serialize the value types to an array pointer
+        let mpk_data = Value::Map(vec![
+            (Value::String("chunks".into()), chunks.clone() ),
+            (Value::String("siblings".into()), siblings_mpk.clone() ),
+            (Value::String("hashes".into()), hashes_mpk.clone() ),
+            (Value::String("path".into()), path_mpk.clone() ),
+            (Value::String("root".into()), root_mpk.clone() ),
+            (Value::String("salt".into()), root_mpk.clone() ),
+        ]);
+        write_value(&mut buf, &mpk_data ).unwrap();
+        let rd: &[u8] = &buf[..];
+        
+        let mut file = File::create("proof_test.mpack").unwrap();
+        file.write_all(rd).unwrap();
+
+        let args_buff = Buffer {
+            data: rd.as_ptr() as *const u8,
+            len: rd.len(),
+        };
+
+        let r1cs_path = "src/circuit_tests/artifacts/storer-test.r1cs";
+        let wasm_path = "src/circuit_tests/artifacts/storer-test_js/storer-test.wasm";
+
+        let r1cs = Buffer {
+            data: r1cs_path.as_ptr(),
+            len: r1cs_path.len(),
+        };
+
+        let wasm = Buffer {
+            data: wasm_path.as_ptr(),
+            len: wasm_path.len(),
+        };
+
+        let prover_ptr = unsafe { init_storage_proofs(r1cs, wasm, std::ptr::null()) };
+        let prove_ctx: *mut crate::ffi::ProofCtx = unsafe {
+            prove_mpack_ext(
+                prover_ptr,
+                &args_buff as *const Buffer,
+            )
+        };
+
+        assert!(prove_ctx.is_null() == false);
+    }
 
     #[test]
     fn test_storer_ffi() {
@@ -201,7 +413,7 @@ mod tests {
         // and hash is the hash of each vector generated using the digest function
         let data = (0..4)
             .map(|_| {
-                let rng = ThreadRng::default();
+                let rng = StdRng::seed_from_u64(42);
                 let preimages: Vec<U256> = rng
                     .sample_iter(Alphanumeric)
                     .take(256)
@@ -272,18 +484,18 @@ mod tests {
         let r1cs_path = "src/circuit_tests/artifacts/storer-test.r1cs";
         let wasm_path = "src/circuit_tests/artifacts/storer-test_js/storer-test.wasm";
 
-        let r1cs = &Buffer {
+        let r1cs = Buffer {
             data: r1cs_path.as_ptr(),
             len: r1cs_path.len(),
         };
 
-        let wasm = &Buffer {
+        let wasm = Buffer {
             data: wasm_path.as_ptr(),
             len: wasm_path.len(),
         };
 
-        let prover_ptr = unsafe { init(&r1cs, &wasm, std::ptr::null()) };
-        let prove_ctx = unsafe {
+        let prover_ptr = unsafe { init_storage_proofs(r1cs, wasm, std::ptr::null()) };
+        let prove_ctx: *mut crate::ffi::ProofCtx = unsafe {
             prove(
                 prover_ptr,
                 &chunks_buff as *const Buffer,

src/storage_proofs.rs

@@ -1,7 +1,7 @@
 use std::fs::File;
 
 use ark_bn254::{Bn254, Fr};
-use ark_circom::{read_zkey, CircomBuilder, CircomConfig};
+use ark_circom::{read_zkey, CircomBuilder, CircomConfig, CircomCircuit};
 use ark_groth16::{
     create_random_proof as prove, generate_random_parameters, prepare_verifying_key, verify_proof,
     Proof, ProvingKey,
@@ -10,6 +10,15 @@ use ark_serialize::{CanonicalDeserialize, CanonicalSerialize, Read};
 use ark_std::rand::rngs::ThreadRng;
 use ruint::aliases::U256;
 
+use rmpv;
+use rmpv::decode::read_value;
+
+type Params256Ty = ark_ec::bn::Bn<ark_bn254::Parameters>;
+
+pub const EXT_ID_U256_LE: i8 = 50;
+pub const EXT_ID_U256_BE: i8 = 51;
+
+
 #[derive(Debug, Clone)]
 pub struct StorageProofs {
     builder: CircomBuilder<Bn254>,
@@ -41,6 +50,36 @@ impl StorageProofs {
         }
     }
 
+    pub fn prove_mpack(
+        &mut self,
+        inputs: &[u8],
+        proof_bytes: &mut Vec<u8>,
+        public_inputs_bytes: &mut Vec<u8>,
+    ) -> Result<(), String> {
+        let mut builder: CircomBuilder<Params256Ty> = self.builder.clone();
+
+        parse_mpack_args(&mut builder, inputs)?;
+
+        let circuit: CircomCircuit<Params256Ty> = builder.build()
+            .map_err(|e| e.to_string())?;
+
+        let inputs = circuit
+            .get_public_inputs()
+            .ok_or("Unable to get public inputs!")?;
+        let proof =
+            prove(circuit, &self.params, &mut self.rng)
+            .map_err(|e| e.to_string())?;
+
+        proof
+            .serialize(proof_bytes)
+            .map_err(|e| e.to_string())?;
+        inputs
+            .serialize(public_inputs_bytes)
+            .map_err(|e| e.to_string())?;
+
+        Ok(())
+    }
+
     pub fn prove(
         &mut self,
         chunks: &[U256],
@@ -96,3 +135,95 @@ impl StorageProofs {
         Ok(())
     }
 }
+
+fn decode_number(val: &rmpv::Value) -> Result<U256, String> {
+    match val {
+        rmpv::Value::Ext(id, val) => {
+            match *id {
+                EXT_ID_U256_LE =>
+                    match U256::try_from_le_slice(val) {
+                        Some(i) => Ok(i),
+                        None => Err("error parsing 256".to_string()),
+                    }
+                num => return Err(format!("unhandled ext id {}", num)),
+            }
+        },
+        rmpv::Value::Integer(val) => {
+            if let Some(val) = val.as_u64() {
+                return Ok(U256::from(val));
+            } else if let Some(val) = val.as_i64() {
+                return Ok(U256::from(val));
+            } else {
+                return Err("unexpected integer kind".to_string());
+            }
+        }
+        _ => return Err("expected ext mpack kind or integer".to_string()),
+    }
+}
+
+fn parse_mpack_arrays(
+    builder: &mut CircomBuilder<Params256Ty>,
+    name: &str,
+    array: &Vec<rmpv::Value>
+) -> Result<(), String> {
+
+    println!("deserde: array: {} size: {}", name, array.len());
+    if array.len() > 0 && array[0].is_array() {
+        println!("deserde: arrayOfArrays: {}", name);
+        for element in array {
+            match element .as_array() {
+                Some(element ) => {
+                    parse_mpack_arrays(builder, name, element)?;
+                },
+                _ => {
+                    print!("error expected array: {}", name);
+                    return Err("expected inner array of u256".to_string())
+                },
+            }
+        }
+    } else {
+        println!("deserde: name: {}", name);
+        for val in array {
+            let n = decode_number(val)?;
+            println!("\t{}", n);
+            builder.push_input(name, n);
+        }
+        println!("done: name: {}", name);
+    }
+
+    Ok(())
+}
+
+fn parse_mpack_args(
+    builder: &mut CircomBuilder<Params256Ty>,
+    mut inputs: &[u8]
+) -> Result<(), String> {
+    let values: rmpv::Value = read_value(&mut inputs).map_err(|e| e.to_string())?;
+    let args: &Vec<(rmpv::Value, rmpv::Value)> = match values.as_map() {
+        Some(args) => args,
+        None => return Err("args must be a map of string to arrays".to_string()),
+    };
+
+    for (key, val) in args {
+        let name = match key.as_str() {
+            Some(n) => n,
+            None => return Err(format!("expected string value")),
+        };
+        match val {
+            // add a (name, Vec<u256>) or (name, Vev<Vec<u256>>) arrays
+            rmpv::Value::Array(vals) => {
+                parse_mpack_arrays(builder, name, vals)?;
+            },
+            // directly add a (name,u256) arg pair 
+            rmpv::Value::Ext(_, _) => {
+                let n = decode_number(val)?;
+                println!("deserde: name: {} u256: {}", name, n);
+                builder.push_input(name, n);
+            },
+            _ => return Err("unhandled argument kind".to_string()),
+        }
+    }
+
+    println!("parse_mpack_args DONE!");
+    Ok(())
+}

tests/config.nims

@@ -0,0 +1 @@
+--path:"../"

tests/tffi.nim

@@ -0,0 +1,33 @@
+
+import std/os
+import unittest2
+import codex_storage_proofs
+
+suite "storage proofs ffi":
+  test "basic ffi circuit":
+    var
+      r1csPath = "src/circuit_tests/artifacts/storer-test.r1cs".absolutePath()
+      wasmPath = "src/circuit_tests/artifacts/storer-test_js/storer-test.wasm".absolutePath()
+
+    if not r1csPath.fileExists():
+      raise newException(ValueError, "missing expected r1cs file: " & r1csPath)
+    if not wasmPath.fileExists():
+      raise newException(ValueError, "missing expected wasm file: " & wasmPath)
+
+    let
+      r1cs_buff = unsafeBufferPath(r1csPath)
+      wasm_buff = unsafeBufferPath(wasmPath)
+
+    let storage_ctx = init_storage_proofs(r1cs_buff, wasm_buff, nil)
+
+    echo "storage_ctx: ", storage_ctx.repr
+    check storage_ctx != nil
+
+    var
+      mpack_arg_path = "tests/proof_test.mpack"
+      proofBuff = unsafeBufferFromFile(mpack_arg_path)
+    echo "proofArgs:size: ", proofBuff.len()
+    let res = prove_mpack_ext(storage_ctx, addr proofBuff)
+
+    echo "result: ", res.repr
+    check res != nil