From 4b8a38c7f8c9a5fec71cd5057c570513f8844740 Mon Sep 17 00:00:00 2001
From: Sasha <oleksandr@status.im>
Date: Fri, 16 Feb 2024 00:29:21 +0100
Subject: [PATCH] decouple proof related stuff

---
 src/index.ts |  9 ++-----
 src/proof.ts | 67 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/rln.ts   | 70 +++-------------------------------------------------
 3 files changed, 73 insertions(+), 73 deletions(-)
 create mode 100644 src/proof.ts

diff --git a/src/index.ts b/src/index.ts
index 923ab4c..d5b2751 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -7,12 +7,8 @@ import {
 import { RLNContract } from "./contract/index.js";
 import { createRLN } from "./create.js";
 import { Keystore } from "./keystore/index.js";
-import {
-  IdentityCredential,
-  Proof,
-  ProofMetadata,
-  RLNInstance,
-} from "./rln.js";
+import { Proof } from "./proof.js";
+import { IdentityCredential, RLNInstance } from "./rln.js";
 import { MerkleRootTracker } from "./root_tracker.js";
 import { extractMetaMaskSigner } from "./utils/index.js";
 
@@ -22,7 +18,6 @@ export {
   RLNInstance,
   IdentityCredential,
   Proof,
-  ProofMetadata,
   RLNEncoder,
   RLNDecoder,
   MerkleRootTracker,
diff --git a/src/proof.ts b/src/proof.ts
new file mode 100644
index 0000000..0aea21e
--- /dev/null
+++ b/src/proof.ts
@@ -0,0 +1,67 @@
+import type { IRateLimitProof } from "@waku/interfaces";
+
+import { concatenate, poseidonHash } from "./utils/index.js";
+
+const proofOffset = 128;
+const rootOffset = proofOffset + 32;
+const epochOffset = rootOffset + 32;
+const shareXOffset = epochOffset + 32;
+const shareYOffset = shareXOffset + 32;
+const nullifierOffset = shareYOffset + 32;
+const rlnIdentifierOffset = nullifierOffset + 32;
+
+class ProofMetadata {
+  constructor(
+    public readonly nullifier: Uint8Array,
+    public readonly shareX: Uint8Array,
+    public readonly shareY: Uint8Array,
+    public readonly externalNullifier: Uint8Array
+  ) {}
+}
+
+export class Proof implements IRateLimitProof {
+  readonly proof: Uint8Array;
+  readonly merkleRoot: Uint8Array;
+  readonly epoch: Uint8Array;
+  readonly shareX: Uint8Array;
+  readonly shareY: Uint8Array;
+  readonly nullifier: Uint8Array;
+  readonly rlnIdentifier: Uint8Array;
+
+  constructor(proofBytes: Uint8Array) {
+    if (proofBytes.length < rlnIdentifierOffset) throw "invalid proof";
+    // parse the proof as proof<128> | share_y<32> | nullifier<32> | root<32> | epoch<32> | share_x<32> | rln_identifier<32>
+    this.proof = proofBytes.subarray(0, proofOffset);
+    this.merkleRoot = proofBytes.subarray(proofOffset, rootOffset);
+    this.epoch = proofBytes.subarray(rootOffset, epochOffset);
+    this.shareX = proofBytes.subarray(epochOffset, shareXOffset);
+    this.shareY = proofBytes.subarray(shareXOffset, shareYOffset);
+    this.nullifier = proofBytes.subarray(shareYOffset, nullifierOffset);
+    this.rlnIdentifier = proofBytes.subarray(
+      nullifierOffset,
+      rlnIdentifierOffset
+    );
+  }
+
+  extractMetadata(): ProofMetadata {
+    const externalNullifier = poseidonHash(this.epoch, this.rlnIdentifier);
+    return new ProofMetadata(
+      this.nullifier,
+      this.shareX,
+      this.shareY,
+      externalNullifier
+    );
+  }
+}
+
+export function proofToBytes(p: IRateLimitProof): Uint8Array {
+  return concatenate(
+    p.proof,
+    p.merkleRoot,
+    p.epoch,
+    p.shareX,
+    p.shareY,
+    p.nullifier,
+    p.rlnIdentifier
+  );
+}
diff --git a/src/rln.ts b/src/rln.ts
index f33af94..d50977a 100644
--- a/src/rln.ts
+++ b/src/rln.ts
@@ -1,8 +1,8 @@
 import { createDecoder, createEncoder } from "@waku/core";
-import type { IRateLimitProof } from "@waku/interfaces";
 import type {
   ContentTopic,
   IDecodedMessage,
+  IRateLimitProof,
   EncoderOptions as WakuEncoderOptions,
 } from "@waku/interfaces";
 import init from "@waku/zerokit-rln-wasm";
@@ -20,13 +20,14 @@ import type {
   EncryptedCredentials,
 } from "./keystore/index.js";
 import { KeystoreEntity, Password } from "./keystore/types.js";
+import { Proof, proofToBytes } from "./proof.js";
 import verificationKey from "./resources/verification_key.js";
 import {
   buildBigIntFromUint8Array,
-  poseidonHash,
+  concatenate,
+  extractMetaMaskSigner,
   writeUIntLE,
 } from "./utils/index.js";
-import { concatenate, extractMetaMaskSigner } from "./utils/index.js";
 import * as wc from "./witness_calculator.js";
 import { WitnessCalculator } from "./witness_calculator.js";
 
@@ -88,69 +89,6 @@ export class IdentityCredential {
   }
 }
 
-const proofOffset = 128;
-const rootOffset = proofOffset + 32;
-const epochOffset = rootOffset + 32;
-const shareXOffset = epochOffset + 32;
-const shareYOffset = shareXOffset + 32;
-const nullifierOffset = shareYOffset + 32;
-const rlnIdentifierOffset = nullifierOffset + 32;
-
-export class ProofMetadata {
-  constructor(
-    public readonly nullifier: Uint8Array,
-    public readonly shareX: Uint8Array,
-    public readonly shareY: Uint8Array,
-    public readonly externalNullifier: Uint8Array
-  ) {}
-}
-export class Proof implements IRateLimitProof {
-  readonly proof: Uint8Array;
-  readonly merkleRoot: Uint8Array;
-  readonly epoch: Uint8Array;
-  readonly shareX: Uint8Array;
-  readonly shareY: Uint8Array;
-  readonly nullifier: Uint8Array;
-  readonly rlnIdentifier: Uint8Array;
-
-  constructor(proofBytes: Uint8Array) {
-    if (proofBytes.length < rlnIdentifierOffset) throw "invalid proof";
-    // parse the proof as proof<128> | share_y<32> | nullifier<32> | root<32> | epoch<32> | share_x<32> | rln_identifier<32>
-    this.proof = proofBytes.subarray(0, proofOffset);
-    this.merkleRoot = proofBytes.subarray(proofOffset, rootOffset);
-    this.epoch = proofBytes.subarray(rootOffset, epochOffset);
-    this.shareX = proofBytes.subarray(epochOffset, shareXOffset);
-    this.shareY = proofBytes.subarray(shareXOffset, shareYOffset);
-    this.nullifier = proofBytes.subarray(shareYOffset, nullifierOffset);
-    this.rlnIdentifier = proofBytes.subarray(
-      nullifierOffset,
-      rlnIdentifierOffset
-    );
-  }
-
-  extractMetadata(): ProofMetadata {
-    const externalNullifier = poseidonHash(this.epoch, this.rlnIdentifier);
-    return new ProofMetadata(
-      this.nullifier,
-      this.shareX,
-      this.shareY,
-      externalNullifier
-    );
-  }
-}
-
-export function proofToBytes(p: IRateLimitProof): Uint8Array {
-  return concatenate(
-    p.proof,
-    p.merkleRoot,
-    p.epoch,
-    p.shareX,
-    p.shareY,
-    p.nullifier,
-    p.rlnIdentifier
-  );
-}
-
 type StartRLNOptions = {
   /**
    * If not set - will extract MetaMask account and get signer from it.