ETH address conversion + storing parachain in URL

Fixes #459

I'm still thinking on how to properly test ethereum drips, will follow
up on that.

client/src/lib/components/NetworkInput.svelte

@@ -1,4 +1,6 @@
 <script lang="ts">
+  import { goto } from "$app/navigation";
+  import { page } from "$app/stores";
   import { testnet } from "$lib/utils/stores";
 
   import { getChainName } from "../utils/networkData";
@@ -31,6 +33,13 @@
       elem?.blur();
     }
     network = chain;
+    if (chain === -1) {
+      $page.url.searchParams.delete("parachain");
+    } else {
+      $page.url.searchParams.set("parachain", chain.toString());
+    }
+
+    goto(`?${$page.url.searchParams.toString()}`);
   }
 </script>
 

client/src/lib/utils/stores.ts

@@ -1,12 +1,10 @@
-import { derived, writable } from "svelte/store";
+import { writable } from "svelte/store";
 
 import { type NetworkData, Paseo } from "./networkData";
 
 // Defaults to Paseo, being updated in Faucet.svelte
 export const testnet = writable<NetworkData>(Paseo);
 
-export const testnetName = derived(testnet, ($net) => $net.networkName);
-
 interface FaucetOperation {
   success: boolean;
   hash: string;

package.json

@@ -52,6 +52,7 @@
   },
   "dependencies": {
     "@eng-automation/js": "^2.1.0",
+    "@noble/hashes": "^1.5.0",
     "@polkadot-api/descriptors": "portal:.papi/descriptors",
     "@polkadot-labs/hdkd": "^0.0.6",
     "@polkadot-labs/hdkd-helpers": "^0.0.6",

src/bot/index.ts

@@ -5,7 +5,7 @@ import { convertAmountToBn, convertBnAmountToNumber, formatAmount } from "#src/d
 import { isDripSuccessResponse } from "#src/guards";
 import { logger } from "#src/logger";
 import { getNetworkData } from "#src/papi/index";
-import { isAccountPrivileged } from "#src/utils";
+import { ethAddressToSS58, isAccountPrivileged } from "#src/utils";
 import * as mSDK from "matrix-js-sdk";
 import { AccountId } from "polkadot-api";
 
@@ -129,10 +129,15 @@ bot.on(mSDK.RoomEvent.Timeline, (event: mSDK.MatrixEvent) => {
     }
 
     const arg0_processed = arg0.trim().split(":");
-    const address = arg0_processed[0];
+    let address = arg0_processed[0];
     const parachain_id = arg0_processed[1] ? arg0_processed[1] : "";
     logger.debug(`Processed receiver to address ${address} and parachain id ${parachain_id}`);
 
+    if (address.startsWith("0x")) {
+      address = ethAddressToSS58(address, networkData.data.ethToSS58FillPrefix);
+      logger.debug(`Converted ETH address to ${address}`);
+    }
+
     try {
       AccountId().enc(address);
     } catch (e) {

src/faucet.e2e.ts

@@ -225,4 +225,6 @@ describe("Faucet E2E", () => {
       "Requester has reached their daily quota. Only request once per day",
     );
   });
+
+  test.todo("Faucet drips to ethereum address");
 });

src/papi/chains/e2e.ts

@@ -24,6 +24,7 @@ export const networkData: NetworkData = {
   networkName: "Rococo",
   rpcEndpoint: "ws://host.docker.internal:9933/",
   matrixWhitelistPatterns: parityWhitelist,
+  ethToSS58FillPrefix: 0xee,
 };
 
 export const networkApi: NetworkApi = {

src/papi/chains/index.ts

@@ -52,6 +52,8 @@ export interface NetworkData {
   dripAmount: string;
   balanceCap: number;
   matrixWhitelistPatterns: RegExp[];
+  // Should be 0xEE for all our currenly supported chains, but could be different for other chains
+  ethToSS58FillPrefix: number;
 }
 
 export function getNetworkData(networkName: string): { data: NetworkData; api: NetworkApi } {

src/papi/chains/paseo.ts

@@ -33,6 +33,7 @@ const networkData: NetworkData = {
     /^@purpletentacle:matrix\.org$/,
     /^@carlosala:matrix\.org$/,
   ],
+  ethToSS58FillPrefix: 0xee,
 };
 
 export const networkApi: NetworkApi = {

src/papi/chains/versi.ts

@@ -24,6 +24,7 @@ const networkData: NetworkData = {
   networkName: "Versi",
   rpcEndpoint: "wss://versi-rpc-node-0.parity-versi.parity.io/",
   matrixWhitelistPatterns: parityWhitelist,
+  ethToSS58FillPrefix: 0xee,
 };
 
 const networkApi: NetworkApi = {

src/papi/chains/westend.ts

@@ -28,6 +28,7 @@ const networkData: NetworkData = {
   networkName: "Westend",
   rpcEndpoint: "wss://westend-rpc.polkadot.io/",
   matrixWhitelistPatterns: parityWhitelist,
+  ethToSS58FillPrefix: 0xee,
 };
 
 export const networkApi: NetworkApi = {

src/server/routes/actions.ts

@@ -4,6 +4,7 @@ import polkadotActions from "#src/dripper/polkadot/PolkadotActions";
 import { convertAmountToBn, formatAmount } from "#src/dripper/polkadot/utils";
 import { logger } from "#src/logger";
 import { getNetworkData } from "#src/papi/index";
+import { ethAddressToSS58 } from "#src/utils";
 import cors from "cors";
 import express, { NextFunction, Request, Response } from "express";
 
@@ -54,10 +55,19 @@ const addressMiddleware = (
 type PartialDrip<T extends FaucetRequestType | BotRequestType> = Partial<T> & Pick<T, "address">;
 
 router.post<unknown, DripResponse, PartialDrip<FaucetRequestType>>("/drip/web", addressMiddleware, async (req, res) => {
-  const { address, parachain_id, recaptcha } = req.body;
+  const { parachain_id, recaptcha } = req.body;
   if (!recaptcha) {
     return missingParameterError(res, "recaptcha");
   }
+
+  let { address } = req.body;
+
+  logger.debug(`Dripping to ${address}, parachain id ${parachain_id}`);
+  if (address.startsWith("0x")) {
+    address = ethAddressToSS58(address, networkData.data.ethToSS58FillPrefix);
+    logger.debug(`Converted ETH address to ${address}`);
+  }
+
   try {
     const dripResult = await dripRequestHandler.handleRequest({
       external: true,

src/utils.ts

@@ -1,9 +1,21 @@
+import { concatBytes, hexToBytes } from "@noble/hashes/utils";
 import { config } from "#src/config";
 import { getNetworkData } from "#src/papi/index";
+import { AccountId } from "polkadot-api";
 
 export function isAccountPrivileged(sender: string): boolean {
   const networkName = config.Get("NETWORK");
   const networkData = getNetworkData(networkName);
 
   return networkData.data.matrixWhitelistPatterns.some((pattern) => pattern.test(sender));
 }
+
+// copypaste from https://github.com/paritytech/revive-remix/blob/2eca8b351f96734ffc94adc63b94f3587bd8d67d/libs/remix-ui/helper/src/lib/remix-ui-helper.ts#L93
+export function ethAddressToSS58(address: string, prefix: number): string {
+  // Remove '0x' prefix
+  const ethAddress = address.slice(2);
+  const ethAddressBytes = hexToBytes(ethAddress);
+  // Pad the address to 32 bytes with `0xEE`
+  const paddedAddress = concatBytes(ethAddressBytes, new Uint8Array(32 - ethAddressBytes.length).fill(prefix));
+  return AccountId().dec(paddedAddress);
+}

yarn.lock

@@ -5090,6 +5090,7 @@ __metadata:
     "@eng-automation/js": "npm:^2.1.0"
     "@eng-automation/js-style": "npm:^3.1.0"
     "@eng-automation/testing": "npm:^1.5.1"
+    "@noble/hashes": "npm:^1.5.0"
     "@polkadot-api/descriptors": "portal:.papi/descriptors"
     "@polkadot-labs/hdkd": "npm:^0.0.6"
     "@polkadot-labs/hdkd-helpers": "npm:^0.0.6"