Ethereum keypair signing & verification (#664)

* Ethereum keypair signing & verification

* Verify against hashes expanded

* Adjust via flags

* ss58 encoding for 33-byte publicKey

* ecdsa types stores address as raw publicKey

* Adjust for hash lengths

* Adjust expand/compress specs

packages/util-crypto/src/address/checkChecksum.ts

@@ -5,7 +5,7 @@
 import sshash from './sshash';
 
 export default function checkChecksum (decoded: Uint8Array): [boolean, number] {
-  const isPublicKey = decoded.length === 35;
+  const isPublicKey = [35, 36].includes(decoded.length);
 
   // non-publicKeys has 1 byte checksums, else default to 2
   const length = decoded.length - (isPublicKey ? 2 : 1);

packages/util-crypto/src/address/decode.spec.ts

@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { stringToU8a, u8aToHex } from '@polkadot/util';
+import { stringToU8a, u8aToHex, hexToU8a } from '@polkadot/util';
 
 import testingPairs, { TestKeyringMap } from '../../../keyring/src/testingPairs';
 import decode from './decode';
@@ -74,6 +74,14 @@ describe('decodeAddress', (): void => {
     ).toEqual(new Uint8Array([42, 44, 10, 0, 0, 0, 0, 0]));
   });
 
+  it('decodes a 33-byte address', (): void => {
+    expect(
+      decode('KWCv1L3QX9LDPwY4VzvLmarEmXjVJidUzZcinvVnmxAJJCBou')
+    ).toEqual(
+      hexToU8a('0x03b9dc646dd71118e5f7fda681ad9eca36eb3ee96f344f582fbe7b5bcdebb13077')
+    );
+  });
+
   it.skip('allows invalid prefix (in list)', (): void => {
     expect(
       (): Uint8Array => decode('6GfvWUvHvU8otbZ7sFhXH4eYeMcKdUkL61P3nFy52efEPVUx')

packages/util-crypto/src/address/defaults.ts

@@ -5,9 +5,9 @@
 import { allowedSS58 } from './ss58';
 
 const defaults = {
-  allowedDecodedLengths: [1, 2, 4, 8, 32],
+  allowedDecodedLengths: [1, 2, 4, 8, 32, 33],
   // publicKey has prefix + 2 checksum bytes, short only prefix + 1 checksum byte
-  allowedEncodedLengths: [3, 4, 6, 10, 35],
+  allowedEncodedLengths: [3, 4, 6, 10, 35, 36],
   allowedPrefix: allowedSS58,
   prefix: 42
 };

packages/util-crypto/src/address/encode.spec.ts

@@ -67,11 +67,17 @@ describe('encode', (): void => {
     ).toEqual('as7QnGMf');
   });
 
-  it('enodes a 8-byte address', (): void => {
+  it('encodes a 8-byte address', (): void => {
     expect(
       encode(
         new Uint8Array([42, 44, 10, 0, 0, 0, 0, 0]), 68
       )
     ).toEqual('4q7qY5RBG7Z4wv');
   });
+
+  it('encodes an 33-byte address', (): void => {
+    expect(
+      encode('0x03b9dc646dd71118e5f7fda681ad9eca36eb3ee96f344f582fbe7b5bcdebb13077')
+    ).toEqual('KWCv1L3QX9LDPwY4VzvLmarEmXjVJidUzZcinvVnmxAJJCBou');
+  });
 });

packages/util-crypto/src/address/encode.ts

@@ -19,7 +19,7 @@ export default function encode (_key: Uint8Array | string, ss58Format: Prefix =
 
   assert(defaults.allowedDecodedLengths.includes(key.length), `Expected a valid key to convert, with length ${defaults.allowedDecodedLengths.join(', ')}`);
 
-  const isPublicKey = key.length === 32;
+  const isPublicKey = [32, 33].includes(key.length);
   const input = u8aConcat(new Uint8Array([ss58Format]), key);
   const hash = sshash(input);