diff --git a/lib/utils/ens-cache.js b/lib/utils/ens-cache.js index e4204aa94..054fc7163 100644 --- a/lib/utils/ens-cache.js +++ b/lib/utils/ens-cache.js @@ -1,241 +1,332 @@ // @flow import namehash from 'eth-ens-namehash'; import sleep from './sleep.js'; const cacheTimeout = 24 * 60 * 60 * 1000; // one day const failedQueryCacheTimeout = 5 * 60 * 1000; // five minutes const queryTimeout = 10 * 1000; // ten seconds async function throwOnTimeout(identifier: string) { await sleep(queryTimeout); throw new Error(`ENS fetch for ${identifier} timed out`); } export type EthersProvider = { +lookupAddress: (address: string) => Promise, +resolveName: (name: string) => Promise, + +getAvatar: (name: string) => Promise, ... }; type ENSNameQueryCacheEntry = { // We normalize ETH addresses to lowercase characters +normalizedETHAddress: string, +expirationTime: number, // We normalize ENS names using eth-ens-namehash +normalizedENSName: ?string | Promise, }; type ENSAddressQueryCacheEntry = { +normalizedENSName: string, +expirationTime: number, +normalizedETHAddress: ?string | Promise, }; +type ENSAvatarQueryCacheEntry = { + +normalizedETHAddress: string, + +expirationTime: number, + +avatarURI: ?string | Promise, +}; const normalizeETHAddress = (ethAddress: string) => ethAddress.toLowerCase(); // Note: this normalization is a little different than the ETH address // normalization. The difference is that ETH addresses are // case-insensitive, but a normalized ENS name is not the same as its input. // Whereas we use normalizeETHAddress just to dedup inputs, we use this // function to check if an ENS name matches its normalized ENS name, as a way // to prevent homograph attacks. // See https://docs.ens.domains/dapp-developer-guide/resolving-names#reverse-resolution const normalizeENSName = (ensName: string) => namehash.normalize(ensName); // We have a need for querying ENS names from both clients as well as from // keyserver code. On the client side, we could use wagmi's caching behavior, // but that doesn't work for keyserver since it's React-specific. To keep // caching behavior consistent across platforms, we instead introduce this // vanilla JS class that handles querying and caching ENS for all cases. class ENSCache { provider: EthersProvider; - // Maps from normalized ETH address to a cache entry for that address + // Maps from normalized ETH address to a cache entry for its name nameQueryCache: Map = new Map(); - // Maps from normalized ETH name to a cache entry for that name + // Maps from normalized ETH name to a cache entry for its address addressQueryCache: Map = new Map(); + // Maps from normalized ETH address to a cache entry for its avatar + avatarQueryCache: Map = new Map(); constructor(provider: EthersProvider) { this.provider = provider; } // Getting a name for an ETH address is referred to as "reverse resolution". // 1. Since any address can set a reverse resolution to an arbitrary ENS name // (without permission from the owner), this function will also perform a // "forward resolution" to confirm that the owner of the ENS name has // mapped it to this address // 2. We only consider an ENS name valid if it's equal to its normalized // version via eth-ens-namehash. This is to protect against homograph // attacks // If we fail to find an ENS name for an address, fail to confirm a matching // forward resolution, or if the ENS name does not equal its normalized // version, we will return undefined. getNameForAddress(ethAddress: string): Promise { const normalizedETHAddress = normalizeETHAddress(ethAddress); const cacheResult = this.getCachedNameEntryForAddress(normalizedETHAddress); if (cacheResult) { return Promise.resolve(cacheResult.normalizedENSName); } const fetchENSNamePromise = (async () => { // ethers.js handles checking forward resolution (point 1 above) for us let ensName; try { ensName = await Promise.race([ this.provider.lookupAddress(normalizedETHAddress), throwOnTimeout(`${normalizedETHAddress}'s name`), ]); } catch (e) { console.log(e); return null; } if (!ensName) { return undefined; } const normalizedENSName = normalizeENSName(ensName); if (normalizedENSName !== ensName) { return undefined; } return normalizedENSName; })(); this.nameQueryCache.set(normalizedETHAddress, { normalizedETHAddress, expirationTime: Date.now() + queryTimeout * 2, normalizedENSName: fetchENSNamePromise, }); return (async () => { const normalizedENSName = await fetchENSNamePromise; const timeout = normalizedENSName === null ? failedQueryCacheTimeout : cacheTimeout; this.nameQueryCache.set(normalizedETHAddress, { normalizedETHAddress, expirationTime: Date.now() + timeout, normalizedENSName, }); return normalizedENSName; })(); } getCachedNameEntryForAddress(ethAddress: string): ?ENSNameQueryCacheEntry { const normalizedETHAddress = normalizeETHAddress(ethAddress); const cacheResult = this.nameQueryCache.get(normalizedETHAddress); if (!cacheResult) { return undefined; } const { expirationTime } = cacheResult; if (expirationTime <= Date.now()) { this.nameQueryCache.delete(normalizedETHAddress); return undefined; } return cacheResult; } getCachedNameForAddress(ethAddress: string): ?string { const cacheResult = this.getCachedNameEntryForAddress(ethAddress); if (!cacheResult) { return undefined; } const { normalizedENSName } = cacheResult; if (typeof normalizedENSName !== 'string') { return undefined; } return normalizedENSName; } getAddressForName(ensName: string): Promise { const normalizedENSName = normalizeENSName(ensName); if (normalizedENSName !== ensName) { return Promise.resolve(undefined); } const cacheResult = this.getCachedAddressEntryForName(normalizedENSName); if (cacheResult) { return Promise.resolve(cacheResult.normalizedETHAddress); } const fetchETHAddressPromise = (async () => { let ethAddress; try { ethAddress = await Promise.race([ this.provider.resolveName(normalizedENSName), throwOnTimeout(`${normalizedENSName}'s address`), ]); } catch (e) { console.log(e); return null; } if (!ethAddress) { return undefined; } return normalizeETHAddress(ethAddress); })(); this.addressQueryCache.set(normalizedENSName, { normalizedENSName, expirationTime: Date.now() + queryTimeout * 2, normalizedETHAddress: fetchETHAddressPromise, }); return (async () => { const normalizedETHAddress = await fetchETHAddressPromise; const timeout = normalizedETHAddress === null ? failedQueryCacheTimeout : cacheTimeout; this.addressQueryCache.set(normalizedENSName, { normalizedENSName, expirationTime: Date.now() + timeout, normalizedETHAddress, }); return normalizedETHAddress; })(); } getCachedAddressEntryForName(ensName: string): ?ENSAddressQueryCacheEntry { const normalizedENSName = normalizeENSName(ensName); if (normalizedENSName !== ensName) { return undefined; } const cacheResult = this.addressQueryCache.get(normalizedENSName); if (!cacheResult) { return undefined; } const { expirationTime } = cacheResult; if (expirationTime <= Date.now()) { this.addressQueryCache.delete(normalizedENSName); return undefined; } return cacheResult; } getCachedAddressForName(ensName: string): ?string { const cacheResult = this.getCachedAddressEntryForName(ensName); if (!cacheResult) { return undefined; } const { normalizedETHAddress } = cacheResult; if (typeof normalizedETHAddress !== 'string') { return undefined; } return normalizedETHAddress; } + getAvatarURIForAddress(ethAddress: string): Promise { + const normalizedETHAddress = normalizeETHAddress(ethAddress); + + const cacheResult = + this.getCachedAvatarEntryForAddress(normalizedETHAddress); + if (cacheResult) { + return Promise.resolve(cacheResult.avatarURI); + } + + const fetchENSAvatarPromise = (async () => { + const ensName = await this.getNameForAddress(normalizedETHAddress); + if (!ensName) { + return ensName; + } + let ensAvatar; + try { + ensAvatar = await Promise.race([ + this.provider.getAvatar(ensName), + throwOnTimeout(`${normalizedETHAddress}'s avatar`), + ]); + } catch (e) { + console.log(e); + return null; + } + if (!ensAvatar) { + return undefined; + } + return ensAvatar; + })(); + + this.avatarQueryCache.set(normalizedETHAddress, { + normalizedETHAddress, + expirationTime: Date.now() + queryTimeout * 4, + avatarURI: fetchENSAvatarPromise, + }); + + return (async () => { + const avatarURI = await fetchENSAvatarPromise; + const timeout = + avatarURI === null ? failedQueryCacheTimeout : cacheTimeout; + this.avatarQueryCache.set(normalizedETHAddress, { + normalizedETHAddress, + expirationTime: Date.now() + timeout, + avatarURI, + }); + return avatarURI; + })(); + } + + getCachedAvatarEntryForAddress( + ethAddress: string, + ): ?ENSAvatarQueryCacheEntry { + const normalizedETHAddress = normalizeETHAddress(ethAddress); + + const cacheResult = this.avatarQueryCache.get(normalizedETHAddress); + if (!cacheResult) { + return undefined; + } + + const { expirationTime } = cacheResult; + if (expirationTime <= Date.now()) { + this.avatarQueryCache.delete(normalizedETHAddress); + return undefined; + } + + return cacheResult; + } + + getCachedAvatarURIForAddress(ethAddress: string): ?string { + const cacheResult = this.getCachedAvatarEntryForAddress(ethAddress); + if (!cacheResult) { + return undefined; + } + + const { avatarURI } = cacheResult; + if (typeof avatarURI !== 'string') { + return undefined; + } + + return avatarURI; + } + clearCache(): void { this.nameQueryCache = new Map(); this.addressQueryCache = new Map(); + this.avatarQueryCache = new Map(); } } export { ENSCache };