fix(crypto): reject long form signature lengths

Co-authored-by: Air1 <erwann@ark.io>
ArkEcosystem · Dec 3, 2020 · 8f8976d · 8f8976d
1 parent 72f99b9
commit 8f8976d
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Showing 2 changed files with 48 additions and 2 deletions.
diff --git a/__tests__/unit/crypto/blocks/block.test.ts b/__tests__/unit/crypto/blocks/block.test.ts
@@ -488,6 +488,48 @@ describe("Block", () => {
             expect(blockInvalidR.verification.errors).toEqual(["Failed to verify block signature"]);
         });
 
+        it("should fail to verify a block with long form signature", () => {
+            const block = BlockFactory.fromData({
+                id: "62b348a7aba2c60506929eec1311eaecb48ef232d4b154db2ede3f5e53700be9",
+                version: 0,
+                timestamp: 102041016,
+                height: 5470549,
+                reward: Utils.BigNumber.make("200000000"),
+                previousBlock: "2d270cae7e2bd9da27f6160b521859820f2c90315672e1774733bdd6415abb86",
+                numberOfTransactions: 0,
+                totalAmount: Utils.BigNumber.ZERO,
+                totalFee: Utils.BigNumber.ZERO,
+                payloadLength: 0,
+                payloadHash: "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+                generatorPublicKey: "026a423b3323de175dd82788c7eab57850c6a37ea6a470308ebadd7007baf8ceb3",
+                blockSignature:
+                    "3045022100c92d7d0c3ea2ba72576f6494a81fc498d0420286896f806a7ead443d0b5d89720220501610f0d5498d028fd27676ea2597a5cb80cf5896e77fe2fa61623d31ff290c",
+            });
+
+            expect(block.verification.verified).toBeTrue();
+            expect(block.verification.errors).toEqual([]);
+
+            const blockLongFormSig = BlockFactory.fromData({
+                id: "62b348a7aba2c60506929eec1311eaecb48ef232d4b154db2ede3f5e53700be9",
+                version: 0,
+                timestamp: 102041016,
+                height: 5470549,
+                reward: Utils.BigNumber.make("200000000"),
+                previousBlock: "2d270cae7e2bd9da27f6160b521859820f2c90315672e1774733bdd6415abb86",
+                numberOfTransactions: 0,
+                totalAmount: Utils.BigNumber.ZERO,
+                totalFee: Utils.BigNumber.ZERO,
+                payloadLength: 0,
+                payloadHash: "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+                generatorPublicKey: "026a423b3323de175dd82788c7eab57850c6a37ea6a470308ebadd7007baf8ceb3",
+                blockSignature:
+                    "30820045022100c92d7d0c3ea2ba72576f6494a81fc498d0420286896f806a7ead443d0b5d89720220501610f0d5498d028fd27676ea2597a5cb80cf5896e77fe2fa61623d31ff290c0239111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111",
+            });
+
+            expect(blockLongFormSig.verification.verified).toBeFalse();
+            expect(blockLongFormSig.verification.errors).toEqual(["Failed to verify block signature"]);
+        });
+
         it("should construct the block (header only)", () => {
             const block = BlockFactory.fromHex(dummyBlock2.serialized);
             const actual = block.toJson();

diff --git a/packages/crypto/src/crypto/hash.ts b/packages/crypto/src/crypto/hash.ts
@@ -19,14 +19,18 @@ export class Hash {
         const signatureLength = bufferSignature.readUInt8(1);
         const rLength = bufferSignature.readUInt8(3);
         const sLength = bufferSignature.readUInt8(4 + rLength + 1);
-        if (bufferSignature.length !== 4 + rLength + 2 + sLength || signatureLength !== 2 + rLength + 2 + sLength) {
+        if (
+            bufferSignature.length !== 4 + rLength + 2 + sLength ||
+            signatureLength !== 2 + rLength + 2 + sLength ||
+            signatureLength > 127
+        ) {
             return false;
         }
 
         // check that first byte is positive, if it is then the whole R / S will be positive as required
         const rFirstByte = bufferSignature.readInt8(4);
         const sFirstByte = bufferSignature.readInt8(4 + rLength + 2);
-        if (rFirstByte < 0 || sFirstByte < 0) {
+        if (rFirstByte < 0 || sFirstByte < 0 || rFirstByte > 127 || sFirstByte > 127) {
             return false;
         }