Improve point size calculation in toWebCryptoSignature method

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [18.x, 20.x]
+        node-version: [20.x, 22.x]
 
     steps:
       - uses: actions/checkout@v4
@@ -25,21 +25,7 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
-
-      - name: Get yarn cache directory path
-        id: yarn-cache-dir-path
-        run: echo "dir=$(yarn cache dir)" >> $GITHUB_OUTPUT
-
-      - uses: actions/cache@v4
-        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
-        with:
-          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
-          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-yarn-
-
-      - name: Install global dependencies
-        run: npm i yarn -g
+          cache: yarn
 
       - name: Install dependencies
         run: yarn

package.json

@@ -38,27 +38,26 @@
     "shake"
   ],
   "dependencies": {
-    "@peculiar/asn1-schema": "^2.3.8",
+    "@peculiar/asn1-schema": "^2.3.13",
     "@peculiar/json-schema": "^1.1.12",
-    "asn1js": "^3.0.1",
+    "asn1js": "^3.0.5",
     "pvtsutils": "^1.3.5",
-    "tslib": "^2.6.2"
+    "tslib": "^2.7.0"
   },
   "devDependencies": {
-    "@types/mocha": "^10.0.6",
-    "@types/node": "^20.12.12",
+    "@types/mocha": "^10.0.9",
+    "@types/node": "^22.7.5",
     "@typescript-eslint/eslint-plugin": "^7.11.0",
     "@typescript-eslint/parser": "^7.11.0",
-    "coveralls": "^3.1.1",
     "eslint": "^8.57.0",
-    "mocha": "^10.4.0",
-    "nyc": "^15.1.0",
-    "rimraf": "^5.0.7",
-    "rollup": "^4.18.0",
+    "mocha": "^10.7.3",
+    "nyc": "^17.1.0",
+    "rimraf": "^6.0.1",
+    "rollup": "^4.24.0",
     "rollup-plugin-dts": "^6.1.1",
     "rollup-plugin-typescript2": "^0.36.0",
     "ts-node": "^10.9.2",
-    "typescript": "^5.4.5"
+    "typescript": "^5.6.2"
   },
   "author": "PeculiarVentures",
   "license": "MIT",
@@ -91,4 +90,4 @@
       "test/**/*.ts"
     ]
   }
-}
+}

src/asn1/ec_signature.ts

@@ -40,7 +40,16 @@ export class EcDsaSignature {
    * @returns ECDSA signature in X9.62 signature format
    */
   public toWebCryptoSignature(pointSize?: number): ArrayBuffer {
-    pointSize ??= Math.max(this.r.byteLength, this.s.byteLength) * 8;
+    if (!pointSize) {
+      const maxPointLength = Math.max(this.r.byteLength, this.s.byteLength);
+      if (maxPointLength <= 32) {
+        pointSize = 256;
+      } else if (maxPointLength <= 48) {
+        pointSize = 384;
+      } else {
+        pointSize = 521;
+      }
+    }
 
     const signature = EcUtils.encodeSignature(this, pointSize);
 

test/asn1/ec_signature.ts

@@ -44,7 +44,7 @@ context("ASN1", () => {
         asn1: "3081880242011e0ff3c825b1133ef2779bbffd05374b17eeeff37444108a4c480b881ba3f3f426c3344fb1173dcec305f3e49408965092f946e609dfb845efaaaa25a43c679b0c024201a1366cd7b11efe7a41418cf83156bfdac56bb6253fd018a23974fc182948f3a84d5241922f09b8a60c4366f58b2b86461886515bd79872bb55e9840c412db766da",
         webCrypto: "011e0ff3c825b1133ef2779bbffd05374b17eeeff37444108a4c480b881ba3f3f426c3344fb1173dcec305f3e49408965092f946e609dfb845efaaaa25a43c679b0c01a1366cd7b11efe7a41418cf83156bfdac56bb6253fd018a23974fc182948f3a84d5241922f09b8a60c4366f58b2b86461886515bd79872bb55e9840c412db766da",
       },
-    ]
+    ];
 
     context("From WebCrypto to DER", () => {
       vectors.forEach((vector) => {
@@ -66,6 +66,38 @@ context("ASN1", () => {
       });
     });
 
-  });
+    describe("toWebCryptoSignature", () => {
+      it("default point size should be 256", () => {
+        const signature = new EcDsaSignature();
+        signature.r = new ArrayBuffer(32);
+        signature.s = new ArrayBuffer(32);
+        const result = signature.toWebCryptoSignature();
+        assert.strictEqual(result.byteLength, 64);
+      });
 
+      it("default point size should be 384", () => {
+        const signature = new EcDsaSignature();
+        signature.r = new ArrayBuffer(48);
+        signature.s = new ArrayBuffer(48);
+        const result = signature.toWebCryptoSignature();
+        assert.strictEqual(result.byteLength, 96);
+      });
+
+      it("default point size should be 521", () => {
+        const signature = new EcDsaSignature();
+        signature.r = new ArrayBuffer(65);
+        signature.s = new ArrayBuffer(65);
+        const result = signature.toWebCryptoSignature();
+        assert.strictEqual(result.byteLength, 132);
+      });
+
+      it("should be given point size", () => {
+        const signature = new EcDsaSignature();
+        signature.r = new ArrayBuffer(32);
+        signature.s = new ArrayBuffer(32);
+        const result = signature.toWebCryptoSignature(384);
+        assert.strictEqual(result.byteLength, 96);
+      });
+    });
+  });
 });