feat(frontend,devOps): Split backend (#2043)

# Motivation
Here we wish to make the frontend make all its signing API calls to the
signing canister.

# Changes
- Create a signing agent.
- Move all signing API calls from the backend agent to the signer agent.

# Tests
- Existing CI should pass.

src/frontend/src/eth/services/send.services.ts

@@ -19,7 +19,7 @@ import {
 	toCkErc20HelperContractAddress,
 	toCkEthHelperContractAddress
 } from '$icp-eth/utils/cketh.utils';
-import { signTransaction } from '$lib/api/backend.api';
+import { signTransaction } from '$lib/api/signer.api';
 import { DEFAULT_ETHEREUM_NETWORK } from '$lib/constants/networks.constants';
 import { ProgressStepsSend } from '$lib/enums/progress-steps';
 import { i18n } from '$lib/stores/i18n.store';

src/frontend/src/eth/services/wallet-connect.services.ts

@@ -7,7 +7,7 @@ import {
 	getSignParamsMessageTypedDataV4Hash
 } from '$eth/utils/wallet-connect.utils';
 import { assertCkEthMinterInfoLoaded } from '$icp-eth/services/cketh.services';
-import { signMessage as signMessageApi, signPrehash } from '$lib/api/backend.api';
+import { signMessage as signMessageApi, signPrehash } from '$lib/api/signer.api';
 import {
 	TRACK_COUNT_WC_ETH_SEND_ERROR,
 	TRACK_COUNT_WC_ETH_SEND_SUCCESS,

src/frontend/src/lib/actors/actors.ic.ts

@@ -1,7 +1,10 @@
 import type { _SERVICE as BackendActor } from '$declarations/backend/backend.did';
 import { idlFactory as idlCertifiedFactoryBackend } from '$declarations/backend/backend.factory.certified.did';
 import { idlFactory as idlFactoryBackend } from '$declarations/backend/backend.factory.did';
-import { BACKEND_CANISTER_ID } from '$lib/constants/app.constants';
+import type { _SERVICE as SignerActor } from '$declarations/signer/signer.did';
+import { idlFactory as idlCertifiedFactorySigner } from '$declarations/signer/signer.factory.certified.did';
+import { idlFactory as idlFactorySigner } from '$declarations/signer/signer.factory.did';
+import { BACKEND_CANISTER_ID, SIGNER_CANISTER_ID } from '$lib/constants/app.constants';
 import { i18n } from '$lib/stores/i18n.store';
 import type { OptionIdentity } from '$lib/types/identity';
 import { Actor, type ActorMethod, type ActorSubclass, type Identity } from '@dfinity/agent';
@@ -11,7 +14,7 @@ import { assertNonNullish, isNullish } from '@dfinity/utils';
 import { get } from 'svelte/store';
 import { getAgent } from './agents.ic';
 
-let actors: { backend?: BackendActor } | undefined | null = undefined;
+let actors: { backend?: BackendActor; signer?: SignerActor } | undefined | null = undefined;
 
 export const getBackendActor = async ({
 	identity,
@@ -42,6 +45,36 @@ export const getBackendActor = async ({
 	return backend;
 };
 
+export const getSignerActor = async ({
+	identity,
+	certified = true
+}: {
+	identity: OptionIdentity;
+	certified?: boolean;
+}): Promise<SignerActor> => {
+	// TODO: Delete this dependency once the signer has been stripped down.
+	assertNonNullish(identity, get(i18n).auth.error.no_internet_identity);
+
+	const { signer } = actors ?? { signer: undefined };
+
+	if (isNullish(signer)) {
+		const actor = await createActor<SignerActor>({
+			canisterId: SIGNER_CANISTER_ID,
+			idlFactory: certified ? idlCertifiedFactorySigner : idlFactorySigner,
+			identity
+		});
+
+		actors = {
+			...(actors ?? {}),
+			signer: actor
+		};
+
+		return actor;
+	}
+
+	return signer;
+};
+
 export const clearActors = () => (actors = null);
 
 const createActor = async <T = Record<string, ActorMethod>>({

src/frontend/src/lib/api/backend.api.ts

@@ -1,69 +1,17 @@
 import type {
 	AddUserCredentialError,
-	BitcoinNetwork,
 	CredentialSpec,
 	CustomToken,
 	GetUserProfileError,
-	SignRequest,
 	UserProfile,
 	UserToken
 } from '$declarations/backend/backend.did';
 import { getBackendActor } from '$lib/actors/actors.ic';
-import type { EthAddress } from '$lib/types/address';
 import type { OptionIdentity } from '$lib/types/identity';
 import type { Identity } from '@dfinity/agent';
 import type { Principal } from '@dfinity/principal';
 import { toNullable, type QueryParams } from '@dfinity/utils';
 
-export const getBtcAddress = async ({
-	identity,
-	network
-}: {
-	identity: OptionIdentity;
-	network: BitcoinNetwork;
-}): Promise<EthAddress> => {
-	const { caller_btc_address } = await getBackendActor({ identity });
-	return caller_btc_address(network);
-};
-
-export const getEthAddress = async (identity: OptionIdentity): Promise<EthAddress> => {
-	const { caller_eth_address } = await getBackendActor({ identity });
-	return caller_eth_address();
-};
-
-export const signTransaction = async ({
-	transaction,
-	identity
-}: {
-	transaction: SignRequest;
-	identity: OptionIdentity;
-}): Promise<string> => {
-	const { sign_transaction } = await getBackendActor({ identity });
-	return sign_transaction(transaction);
-};
-
-export const signMessage = async ({
-	message,
-	identity
-}: {
-	message: string;
-	identity: OptionIdentity;
-}): Promise<string> => {
-	const { personal_sign } = await getBackendActor({ identity });
-	return personal_sign(message);
-};
-
-export const signPrehash = async ({
-	hash,
-	identity
-}: {
-	hash: string;
-	identity: OptionIdentity;
-}): Promise<string> => {
-	const { sign_prehash } = await getBackendActor({ identity });
-	return sign_prehash(hash);
-};
-
 export const listUserTokens = async ({
 	identity,
 	certified = true

src/frontend/src/lib/api/signer.api.ts

@@ -0,0 +1,53 @@
+import type { BitcoinNetwork, SignRequest } from '$declarations/signer/signer.did';
+import { getBackendActor } from '$lib/actors/actors.ic';
+import type { EthAddress } from '$lib/types/address';
+import type { OptionIdentity } from '$lib/types/identity';
+
+export const getBtcAddress = async ({
+	identity,
+	network
+}: {
+	identity: OptionIdentity;
+	network: BitcoinNetwork;
+}): Promise<EthAddress> => {
+	const { caller_btc_address } = await getBackendActor({ identity });
+	return caller_btc_address(network);
+};
+
+export const getEthAddress = async (identity: OptionIdentity): Promise<EthAddress> => {
+	const { caller_eth_address } = await getBackendActor({ identity });
+	return caller_eth_address();
+};
+
+export const signTransaction = async ({
+	transaction,
+	identity
+}: {
+	transaction: SignRequest;
+	identity: OptionIdentity;
+}): Promise<string> => {
+	const { sign_transaction } = await getBackendActor({ identity });
+	return sign_transaction(transaction);
+};
+
+export const signMessage = async ({
+	message,
+	identity
+}: {
+	message: string;
+	identity: OptionIdentity;
+}): Promise<string> => {
+	const { personal_sign } = await getBackendActor({ identity });
+	return personal_sign(message);
+};
+
+export const signPrehash = async ({
+	hash,
+	identity
+}: {
+	hash: string;
+	identity: OptionIdentity;
+}): Promise<string> => {
+	const { sign_prehash } = await getBackendActor({ identity });
+	return sign_prehash(hash);
+};

src/frontend/src/lib/constants/app.constants.ts

@@ -43,6 +43,12 @@ export const BACKEND_CANISTER_ID = LOCAL
 		? import.meta.env.VITE_STAGING_BACKEND_CANISTER_ID
 		: import.meta.env.VITE_IC_BACKEND_CANISTER_ID;
 
+export const SIGNER_CANISTER_ID = LOCAL
+	? import.meta.env.VITE_LOCAL_SIGNER_CANISTER_ID
+	: STAGING
+		? import.meta.env.VITE_STAGING_SIGNER_CANISTER_ID
+		: import.meta.env.VITE_IC_SIGNER_CANISTER_ID;
+
 // How long the delegation identity should remain valid?
 // e.g. BigInt(60 * 60 * 1000 * 1000 * 1000) = 1 hour in nanoseconds
 export const AUTH_MAX_TIME_TO_LIVE = BigInt(60 * 60 * 1000 * 1000 * 1000);

src/frontend/src/lib/services/address.services.ts

@@ -1,6 +1,5 @@
 import { BTC_MAINNET_TOKEN_ID } from '$env/tokens.btc.env';
 import { ETHEREUM_TOKEN_ID } from '$env/tokens.env';
-import { getBtcAddress, getEthAddress } from '$lib/api/backend.api';
 import {
 	getIdbBtcAddressMainnet,
 	getIdbEthAddress,
@@ -9,6 +8,7 @@ import {
 	updateIdbBtcAddressMainnetLastUsage,
 	updateIdbEthAddressLastUsage
 } from '$lib/api/idb.api';
+import { getBtcAddress, getEthAddress } from '$lib/api/signer.api';
 import { addressStore } from '$lib/stores/address.store';
 import { authStore } from '$lib/stores/auth.store';
 import { i18n } from '$lib/stores/i18n.store';