Merge pull request #6 from tkey/feat/soft-nonce

feat: soft nonce implementation

.github/workflows/backward.yml

@@ -26,12 +26,12 @@ jobs:
     steps:
       - name: checkout tkey repo
         uses: actions/checkout@v3
-        with:
-          path: tkey
+        # with:
+        #   path: tkey
 
-      - name: switch path
-        run: |
-          cd ./tkey
+      # - name: switch path
+      #   run: |
+      #     cd ./tkey
 
       - name: Set up node
         uses: actions/setup-node@v3
@@ -54,7 +54,7 @@ jobs:
         run: |
           cd ./backward-compatibility-tests
           npm i
-          for filename in ../tkey/packages/* ; do
+          for filename in ../packages/* ; do
             echo "installing $filename" || continue
             # ... install packed packages
             packagename="`ls ${filename}| grep tkey`"
@@ -63,5 +63,4 @@ jobs:
 
       - name: Running comp tests
         run: |
-          cd ./backward-compatibility-tests
           npm test

karmaBaseConfig.js

@@ -24,9 +24,9 @@ const localBrowserConfig = (webpackConfig, karmaConfig, packageConfig) => {
     frameworks: ["mocha", "webpack"],
 
     webpack: {
-      module: webpackConfig[1].module,
-      resolve: webpackConfig[1].resolve,
-      plugins: webpackConfig[1].plugins,
+      module: webpackConfig[0].module,
+      resolve: webpackConfig[0].resolve,
+      plugins: webpackConfig[0].plugins,
     },
 
     plugins: ["karma-mocha-reporter", "karma-webkit-launcher", "karma-chrome-launcher", "karma-firefox-launcher", "karma-mocha", "karma-webpack"],

packages/common-types/package.json

@@ -53,7 +53,6 @@
     "ts-custom-error": "^3.3.1"
   },
   "devDependencies": {
-    "@types/bn.js": "^5.1.2",
     "@types/elliptic": "^6.4.15"
   },
   "bugs": {

packages/common-types/src/baseTypes/aggregateTypes.ts

@@ -196,6 +196,7 @@ export interface ShareRequestArgs {
 
 export type TkeyStoreItemType = {
   id: string;
+  value?: string;
 };
 
 export type ISeedPhraseStore = TkeyStoreItemType & {

packages/common-types/src/utils.ts

@@ -104,3 +104,7 @@ export function generateID(): string {
   // after the decimal.
   return `${Math.random().toString(36).substr(2, 9)}`;
 }
+
+export function generateSalt() {
+  return generatePrivate().toString("hex").padStart(64, "0");
+}

packages/core/package.json

@@ -44,7 +44,6 @@
     "json-stable-stringify": "^1.0.2"
   },
   "devDependencies": {
-    "@types/bn.js": "^5.1.2",
     "@types/elliptic": "^6.4.15",
     "@types/json-stable-stringify": "^1.0.34"
   },

packages/core/src/core.ts

@@ -11,6 +11,7 @@ import {
   FromJSONConstructor,
   GenerateNewShareResult,
   generatePrivateExcludingIndexes,
+  generateSalt,
   getPubKeyECC,
   getPubKeyPoint,
   hexPoint,
@@ -52,6 +53,7 @@ import {
   toPrivKeyECC,
 } from "@tkey-mpc/common-types";
 import { generatePrivate } from "@toruslabs/eccrypto";
+import { keccak256 } from "@toruslabs/torus.js";
 import BN from "bn.js";
 import stringify from "json-stable-stringify";
 
@@ -66,8 +68,8 @@ import {
   lagrangeInterpolation,
 } from "./lagrangeInterpolatePolynomial";
 import Metadata from "./metadata";
-
 // TODO: handle errors for get and set with retries
+export const TSS_MODULE = "tssModule";
 
 class ThresholdKey implements ITKey {
   modules: ModuleMap;
@@ -98,6 +100,8 @@ class ThresholdKey implements ITKey {
 
   _shareSerializationMiddleware: ShareSerializationMiddleware;
 
+  _accountSalt: string;
+
   storeDeviceShare: (deviceShareStore: ShareStore, customDeviceInfo?: StringifiedType) => Promise<void>;
 
   haveWriteMetadataLock: string;
@@ -300,6 +304,11 @@ class ThresholdKey implements ITKey {
         });
         if (useTSS) {
           const { factorEncs, factorPubs, tssPolyCommits } = await this._initializeNewTSSKey(this.tssTag, deviceTSSShare, factorPub, deviceTSSIndex);
+          const accountSalt = generateSalt();
+          await this._setTKeyStoreItem(TSS_MODULE, {
+            id: "accountSalt",
+            value: accountSalt,
+          });
           this.metadata.addTSSData({ tssTag: this.tssTag, tssNonce: 0, tssPolyCommits, factorPubs, factorEncs });
         }
         return this.getKeyDetails();
@@ -385,7 +394,7 @@ class ThresholdKey implements ITKey {
    * getTSSShare accepts a factorKey and returns the TSS share based on the factor encrypted TSS shares in the metadata
    * @param factorKey - factor key
    */
-  async getTSSShare(factorKey: BN, opts?: { threshold: number }): Promise<{ tssIndex: number; tssShare: BN }> {
+  async getTSSShare(factorKey: BN, opts?: { threshold: number; accountIndex?: number }): Promise<{ tssIndex: number; tssShare: BN }> {
     if (!this.privKey) throw CoreError.default("tss share cannot be returned until you've reconstructed tkey");
     const factorPub = getPubKeyPoint(factorKey);
     const factorEncs = this.getFactorEncs(factorPub);
@@ -407,6 +416,7 @@ class ThresholdKey implements ITKey {
 
     const userDec = tssShareBNs[0];
 
+    const { threshold, accountIndex } = opts || {};
     if (type === "direct") {
       const tssSharePub = ecCurve.g.mul(userDec);
       const tssCommitA0 = ecCurve.keyFromPublic({ x: tssCommits[0].x.toString(16, 64), y: tssCommits[0].y.toString(16, 64) }).getPublic();
@@ -416,6 +426,11 @@ class ThresholdKey implements ITKey {
         _tssSharePub = _tssSharePub.add(tssCommitA1);
       }
       if (tssSharePub.getX().cmp(_tssSharePub.getX()) === 0 && tssSharePub.getY().cmp(_tssSharePub.getY()) === 0) {
+        if (accountIndex && accountIndex > 0) {
+          const nonce = this.computeAccountNonce(accountIndex);
+          const derivedShare = userDec.add(nonce).umod(ecCurve.n);
+          return { tssIndex, tssShare: derivedShare };
+        }
         return { tssIndex, tssShare: userDec };
       }
       throw new Error("user decryption does not match tss commitments...");
@@ -425,8 +440,6 @@ class ThresholdKey implements ITKey {
     const serverDecs = tssShareBNs.slice(1); // 5 elems
     const serverIndexes = new Array(serverDecs.length).fill(null).map((_, i) => i + 1);
 
-    const { threshold } = opts || {};
-
     const combis = kCombinations(serverDecs.length, threshold || Math.ceil(serverDecs.length / 2));
     for (let i = 0; i < combis.length; i++) {
       const combi = combis[i];
@@ -446,6 +459,11 @@ class ThresholdKey implements ITKey {
         _tssSharePub = _tssSharePub.add(tssCommitA1);
       }
       if (tssSharePub.getX().cmp(_tssSharePub.getX()) === 0 && tssSharePub.getY().cmp(_tssSharePub.getY()) === 0) {
+        if (accountIndex && accountIndex > 0) {
+          const nonce = this.computeAccountNonce(accountIndex);
+          const derivedShare = tssShare.add(nonce).umod(ecCurve.n);
+          return { tssIndex, tssShare: derivedShare };
+        }
         return { tssIndex, tssShare };
       }
     }
@@ -461,8 +479,17 @@ class ThresholdKey implements ITKey {
     return tssPolyCommits;
   }
 
-  getTSSPub(): Point {
-    return this.getTSSCommits()[0];
+  getTSSPub(accountIndex?: number): Point {
+    const tssCommits = this.getTSSCommits();
+    if (accountIndex && accountIndex > 0) {
+      const nonce = this.computeAccountNonce(accountIndex);
+      // we need to add the pub key nonce to the tssPub
+      const noncePub = ecCurve.keyFromPrivate(nonce.toString("hex")).getPublic();
+      const pubKeyPoint = ecCurve.keyFromPublic({ x: tssCommits[0].x.toString("hex"), y: tssCommits[0].y.toString("hex") }).getPublic();
+      const devicePubKeyPoint = pubKeyPoint.add(noncePub);
+      return new Point(devicePubKeyPoint.getX().toString("hex"), devicePubKeyPoint.getY().toString("hex"));
+    }
+    return tssCommits[0];
   }
 
   /**
@@ -593,6 +620,23 @@ class ThresholdKey implements ITKey {
         })
       );
     }
+
+    // only valid for use Tss
+    // assign account salt from tKey store if it exists
+    if (Object.keys(this.metadata.tssPolyCommits).length > 0) {
+      const accountSalt = await this.getTKeyStoreItem(TSS_MODULE, "accountSalt");
+      if (accountSalt && accountSalt?.value) {
+        this._accountSalt = accountSalt.value;
+      } else {
+        const newSalt = generateSalt();
+        await this._setTKeyStoreItem(TSS_MODULE, {
+          id: "accountSalt",
+          value: newSalt,
+        });
+        this._accountSalt = newSalt;
+      }
+    }
+
     return { privKey, ...returnObject };
   }
 
@@ -876,14 +920,18 @@ class ThresholdKey implements ITKey {
           serverEncs: refreshResponse.serverFactorEncs,
         };
       }
+      const accountSalt = generateSalt();
       this.metadata.addTSSData({
         tssTag: this.tssTag,
         tssNonce: newTssNonce,
         tssPolyCommits: newTSSCommits,
         factorPubs,
         factorEncs,
       });
-      await this._syncShareMetadata();
+      await this._setTKeyStoreItem(TSS_MODULE, {
+        id: "accountSalt",
+        value: accountSalt,
+      });
     } catch (error) {
       this.tssTag = oldTag;
       throw error;
@@ -1638,13 +1686,13 @@ class ThresholdKey implements ITKey {
 
     // read errors for what each means
     if (latestMetadata.nonce > this.lastFetchedCloudMetadata.nonce) {
-      throw CoreError.acquireLockFailed(`unable to acquire write access for metadata due to 
+      throw CoreError.acquireLockFailed(`unable to acquire write access for metadata due to
       lastFetchedCloudMetadata (${this.lastFetchedCloudMetadata.nonce})
            being lower than last written metadata nonce (${latestMetadata.nonce}). perhaps update metadata SDK (create new tKey and init)`);
     } else if (latestMetadata.nonce < this.lastFetchedCloudMetadata.nonce) {
-      throw CoreError.acquireLockFailed(`unable to acquire write access for metadata due to 
+      throw CoreError.acquireLockFailed(`unable to acquire write access for metadata due to
       lastFetchedCloudMetadata (${this.lastFetchedCloudMetadata.nonce})
-      being higher than last written metadata nonce (${latestMetadata.nonce}). this should never happen as it 
+      being higher than last written metadata nonce (${latestMetadata.nonce}). this should never happen as it
       should only ever be updated by getting metadata)`);
     }
 
@@ -1933,6 +1981,16 @@ class ThresholdKey implements ITKey {
     this.lastFetchedCloudMetadata = undefined;
   }
 
+  computeAccountNonce(index: number) {
+    // generation should occur during tkey.init, fails if accountSalt is absent
+    if (!this._accountSalt) {
+      throw CoreError.accountSaltUndefined();
+    }
+    let accountHash = keccak256(Buffer.from(`${index}${this._accountSalt}`));
+    if (accountHash.length === 66) accountHash = accountHash.slice(2);
+    return index && index > 0 ? new BN(accountHash, "hex").umod(ecCurve.curve.n) : new BN(0);
+  }
+
   getApi(): ITKeyApi {
     return {
       getMetadata: this.getMetadata.bind(this),