Add experimental caching of keys

package.json

@@ -8,6 +8,7 @@
     "ajv": "^8.6.3",
     "bent": "^7.3.12",
     "body-parser": "^1.19.0",
+    "cache": "^3.0.0",
     "dialog-polyfill": "^0.5.6",
     "doipjs": "^0.16.3",
     "dotenv": "^8.2.0",

server/keys.js

@@ -31,6 +31,10 @@ import got from 'got'
 import * as doipjs from 'doipjs'
 import { readKey, readCleartextMessage, verify } from 'openpgp'
 import { computeWKDLocalPart } from './utils.js'
+import { createHash } from 'crypto'
+import cache from 'cache'
+
+let c = process.env.ENABLE_EXPERIMENTAL_CACHE ? new cache(60 * 1000) : null
 
 const fetchWKD = (id) => {
     return new Promise(async (resolve, reject) => {
@@ -52,6 +56,13 @@ const fetchWKD = (id) => {
         const urlDirect = `https://${domain}/.well-known/openpgpkey/hu/${localEncoded}`
         let plaintext
         
+        const hash = createHash('md5').update(id).digest('hex')
+
+        if (c && c.get(hash)) {
+            plaintext = c.get(hash)
+        }
+
+        if (!plaintext) {
             try {
                 plaintext = await got(urlAdvanced).then((response) => {
                     if (response.statusCode === 200) {
@@ -80,6 +91,11 @@ const fetchWKD = (id) => {
                 reject(new Error(`No public keys could be fetched using WKD`))
             }
 
+            if (c) {
+                c.put(hash, plaintext)
+            }
+        }
+
         try {
             output.publicKey = await readKey({
                 binaryKey: plaintext
@@ -112,17 +128,27 @@ const fetchHKP = (id, keyserverDomain) => {
             query = `0x${id}`
         }
 
+        const hash = createHash('md5').update(`${id}__${keyserverDomain}`).digest('hex')
+
+        if (c && c.get(hash)) {
+            output = c.get(hash)
+        } else {
             try {
                 output.publicKey = await doipjs.keys.fetchHKP(id, keyserverDomain)
                 output.fetchURL = `https://${keyserverDomain}/pks/lookup?op=get&options=mr&search=${query}`
             } catch(error) {
                 reject(new Error(`No public keys could be fetched using HKP`))
             }
+        }
 
         if (!output.publicKey) {
             reject(new Error(`No public keys could be fetched using HKP`))
         }
 
+        if (c) {
+            c.put(hash, output)
+        }
+
         resolve(output)
     })
 }

template.env

@@ -33,3 +33,7 @@
 #KX_HIGHLIGHTS_3_NAME=
 #KX_HIGHLIGHTS_3_DESCRIPTION=
 #KX_HIGHLIGHTS_3_FINGERPRINT=
+
+# Enable caching of keys (experimental)
+# Opt-in; to disable, omit the environment variable
+#ENABLE_EXPERIMENTAL_CACHE=

yarn.lock

@@ -1272,6 +1272,13 @@ bytesish@^0.4.1:
   resolved "https://registry.npmjs.org/bytesish/-/bytesish-0.4.4.tgz"
   integrity sha512-i4uu6M4zuMUiyfZN4RU2+i9+peJh//pXhd9x1oSe1LBkZ3LEbCoygu8W0bXTukU1Jme2txKuotpCZRaC3FLxcQ==
 
+cache@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/cache/-/cache-3.0.0.tgz#1c5857e874f7064be641114a605c7e2ae8a80880"
+  integrity sha512-sNoM5jithfalxIceo/uFFm5bOlGjux2y8jEvjNb0F/cACWQaMmWuEPTLl6GzLHdFcNsbWBBdqkBd9NyefZ5UQQ==
+  dependencies:
+    ds "^1.4.2"
+
 cacheable-lookup@^5.0.3:
   version "5.0.4"
   resolved "https://registry.npmjs.org/cacheable-lookup/-/cacheable-lookup-5.0.4.tgz"
@@ -1816,6 +1823,11 @@ dotenv@^8.2.0:
   resolved "https://registry.npmjs.org/dotenv/-/dotenv-8.2.0.tgz"
   integrity sha512-8sJ78ElpbDJBHNeBzUbUVLsqKdccaa/BXF1uPTw3GrvQTBgrQrtObr2mUrE38vzYd8cEv+m/JBfDLioYcfXoaw==
 
+ds@^1.4.2:
+  version "1.4.2"
+  resolved "https://registry.yarnpkg.com/ds/-/ds-1.4.2.tgz#0857aa213790a4fb3abb365b9cec0e9ba8569393"
+  integrity sha512-d5nMCjfod+srvE/1Bnt/u+L++6N8KJx3ZAi95AGp0g6RtfuGDNlGciWL/iiwKHsFVBVnA3/HEFUq5SW1NgTQ3Q==
+
 duplexer@^0.1.2:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/duplexer/-/duplexer-0.1.2.tgz#3abe43aef3835f8ae077d136ddce0f276b0400e6"