From 8e12083c9d3a1ef6ae964ff117545e859cdf5f51 Mon Sep 17 00:00:00 2001
From: Dmitriy Ryajov <dryajov@gmail.com>
Date: Mon, 12 Feb 2024 13:17:15 -0600
Subject: [PATCH] hookup groth16 verifier types

---
 codex/slots/proofs/backends/circomcompat.nim | 27 +++-----
 codex/slots/proofs/backends/converters.nim   | 70 ++++++++++++++++++++
 codex/slots/proofs/prover.nim                | 20 +++---
 3 files changed, 90 insertions(+), 27 deletions(-)
 create mode 100644 codex/slots/proofs/backends/converters.nim

diff --git a/codex/slots/proofs/backends/circomcompat.nim b/codex/slots/proofs/backends/circomcompat.nim
index 780921ca..43e4213a 100644
--- a/codex/slots/proofs/backends/circomcompat.nim
+++ b/codex/slots/proofs/backends/circomcompat.nim
@@ -20,8 +20,11 @@ import ../../types
 import ../../../stores
 import ../../../merkletree
 import ../../../codextypes
+import ../../../contracts
 
-export circomcompat
+import ./converters
+
+export circomcompat, converters
 
 type
   CircomCompat* = object
@@ -35,13 +38,6 @@ type
     zKeyPath      : string  # path to the zkey file
     backendCfg    : ptr CircomBn254Cfg
 
-  CircomG1* = G1
-  CircomG2* = G2
-
-  CircomProof*  = Proof
-  CircomKey*    = VerifyingKey
-  CircomInputs* = Inputs
-
 proc release*(self: CircomCompat) =
   ## Release the backend
   ##
@@ -64,7 +60,7 @@ proc getVerifyingKey*(
 
 proc prove*[H](
   self: CircomCompat,
-  input: ProofInput[H]): ?!CircomProof =
+  input: ProofInputs[H]): ?!CircomProof =
   ## Encode buffers using a backend
   ##
 
@@ -175,20 +171,19 @@ proc prove*[H](
 
   success proof
 
-proc verify*(
+proc verify*[H](
   self: CircomCompat,
   proof: CircomProof,
-  inputs: CircomInputs,
-  vkp: CircomKey): ?!bool =
+  inputs: ProofInputs[H]): ?!bool =
   ## Verify a proof using a backend
   ##
 
   var
-    proofPtr : ptr Proof = unsafeAddr proof
-    inputsPtr: ptr Inputs = unsafeAddr inputs
-    vpkPtr: ptr CircomKey = unsafeAddr vkp
+    proofPtr = unsafeAddr proof
+    inputs = inputs.toCircomInputs()
+    vkpPtr = ? self.getVerifyingKey()
 
-  let res = verifyCircuit(proofPtr, inputsPtr, vpkPtr)
+  let res = verifyCircuit(proofPtr, inputs.addr, vkpPtr)
   if res == ERR_OK:
     success true
   elif res == ERR_FAILED_TO_VERIFY_PROOF:
diff --git a/codex/slots/proofs/backends/converters.nim b/codex/slots/proofs/backends/converters.nim
new file mode 100644
index 00000000..be5695c3
--- /dev/null
+++ b/codex/slots/proofs/backends/converters.nim
@@ -0,0 +1,70 @@
+## Nim-Codex
+## Copyright (c) 2024 Status Research & Development GmbH
+## Licensed under either of
+##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+## at your option.
+## This file may not be copied, modified, or distributed except according to
+## those terms.
+
+{.push raises: [].}
+
+import pkg/circomcompat
+
+import ../../../contracts
+
+import ../../types
+
+type
+  CircomG1* = G1
+  CircomG2* = G2
+
+  CircomProof*  = Proof
+  CircomKey*    = VerifyingKey
+  CircomInputs* = Inputs
+
+proc toCircomInputs*[H](inputs: ProofInputs[H]): CircomInputs =
+  var
+    slotIndex = inputs.slotIndex.toF.toBytes.toArray32
+    datasetRoot = inputs.datasetRoot.toBytes.toArray32
+    entropy = inputs.entropy.toBytes.toArray32
+
+    elms = [
+      entropy,
+      datasetRoot,
+      slotIndex
+    ]
+
+  let inputsPtr = allocShared0(32 * elms.len)
+  copyMem(inputsPtr, addr elms[0], elms.len * 32)
+
+  CircomInputs(
+    elms: cast[ptr array[32, byte]](inputsPtr),
+    len: elms.len.uint)
+
+proc releaseCircomInputs*(inputs: var CircomInputs) =
+  if not inputs.elms.isNil:
+    deallocShared(inputs.elms)
+    inputs.elms = nil
+
+func toG1*(g: CircomG1): G1Point =
+  G1Point(
+    x: UInt256.fromBytesLE(g.x),
+    y: UInt256.fromBytesLE(g.y))
+
+func toG2*(g: CircomG2): G2Point =
+  G2Point(
+    x: [
+      UInt256.fromBytesLE(g.x[0]),
+      UInt256.fromBytesLE(g.x[1])
+    ],
+    y: [
+      UInt256.fromBytesLE(g.y[0]),
+      UInt256.fromBytesLE(g.y[1])
+    ])
+
+func toGroth16Proof*(proof: CircomProof): Groth16Proof =
+  Groth16Proof(
+    a: proof.a.toG1,
+    b: proof.b.toG2,
+    c: proof.c.toG1)
diff --git a/codex/slots/proofs/prover.nim b/codex/slots/proofs/prover.nim
index 764dcf8e..6288baec 100644
--- a/codex/slots/proofs/prover.nim
+++ b/codex/slots/proofs/prover.nim
@@ -31,14 +31,13 @@ import ../types
 export backends
 
 type
-  AnyProof* = CircomProof
-  AnyInputs* = CircomInputs
-  AnyKeys* = CircomKey
-  AnyHash* = Poseidon2Hash
   AnyBackend* = CircomCompat
-  AnyBuilder* = Poseidon2Builder
-  AnySampler* = Poseidon2Sampler
+  AnyProof* = CircomProof
 
+  AnySampler* = Poseidon2Sampler
+  AnyBuilder* = Poseidon2Builder
+
+  AnyProofInputs* = ProofInputs[Poseidon2Hash]
   Prover* = ref object of RootObj
     backend: AnyBackend
     store: BlockStore
@@ -48,7 +47,7 @@ proc prove*(
   self: Prover,
   slotIdx: int,
   manifest: Manifest,
-  challenge: ProofChallenge): Future[?!AnyProof] {.async.} =
+  challenge: ProofChallenge): Future[?!(AnyProofInputs, AnyProof)] {.async.} =
   ## Prove a statement using backend.
   ## Returns a future that resolves to a proof.
 
@@ -76,17 +75,16 @@ proc prove*(
     error "Unable to prove slot", err = err.msg
     return failure(err)
 
-  success proof
+  success (proofInput, proof)
 
 proc verify*(
   self: Prover,
   proof: AnyProof,
-  inputs: AnyInputs,
-  vpk: AnyKeys): Future[?!bool] {.async.} =
+  inputs: AnyProofInputs): Future[?!bool] {.async.} =
   ## Prove a statement using backend.
   ## Returns a future that resolves to a proof.
 
-  self.backend.verify(proof, inputs, vpk)
+  self.backend.verify(proof, inputs)
 
 proc new*(
   _: type Prover,