feat: expose .well-known

.ebextensions/01env-file-aws-ssm.config

@@ -46,6 +46,7 @@ files:
         aws ssm get-parameter --name "${ENV_TYPE}-verified-fields" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
         aws ssm get-parameter --name "${ENV_TYPE}-webhook-verified-content" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
         aws ssm get-parameter --name "${ENV_TYPE}-wogaa" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
+        aws ssm get-parameter --name "${ENV_TYPE}/formsg-sdk/jwks" --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
         aws ssm get-parameter --name "${ENV_SITE_NAME}-sgid" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
         aws ssm get-parameter --name "${ENV_SITE_NAME}-payment" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env
         aws ssm get-parameter --name "${ENV_SITE_NAME}-cron-payment" --with-decryption --region $AWS_REGION | jq -r '.Parameter.Value' >> $TARGET_DIR/.env

src/app/config/features/formsg-sdk-jwks.config.ts

@@ -0,0 +1,17 @@
+import convict, { Schema } from 'convict'
+
+type FormSgSdkJwks = {
+  publicJwks: string
+}
+
+const formSgSdkJwksSchema: Schema<FormSgSdkJwks> = {
+  publicJwks: {
+    doc: 'JSON Web Key Set for FormSG SDK',
+    form: '*',
+    default: null, // required field
+    env: 'FORMSG_SDK_PUBLIC_JWKS',
+  },
+}
+export const formSgSdkJwksConfig = convict(formSgSdkJwksSchema)
+  .validate({ allowed: 'strict' })
+  .getProperties()

src/app/loaders/express/index.ts

@@ -12,6 +12,7 @@ import * as IntranetMiddleware from '../../modules/intranet/intranet.middleware'
 import { MYINFO_ROUTER_PREFIX } from '../../modules/myinfo/myinfo.constants'
 import { MyInfoRouter } from '../../modules/myinfo/myinfo.routes'
 import { SgidRouter } from '../../modules/sgid/sgid.routes'
+import { WellKnownRouter } from '../../routes/./.well-known'
 import { ApiRouter } from '../../routes/api'
 import { LegacyRedirectRouter } from '../../routes/legacy-redirect'
 import { SpOidcJwksRouter } from '../../routes/singpass'
@@ -123,6 +124,8 @@ const loadExpressApp = async (connection: Connection) => {
   app.use('/sgid', SgidRouter)
   app.use(MYINFO_ROUTER_PREFIX, MyInfoRouter)
 
+  app.use('/.well-known', WellKnownRouter)
+
   // Legacy frontend routes which may still be in use
   app.use(LegacyRedirectRouter)
 
@@ -135,10 +138,7 @@ const loadExpressApp = async (connection: Connection) => {
 
   // If requests for known static asset patterns were not served by
   // the static handlers above, middleware should try to fetch from s3 static bucket or else return 404s
-  app.get(
-    /^\/(public|static|\.well-known)\//,
-    catchNonExistentStaticRoutesMiddleware,
-  )
+  app.get(/^\/(public|static)\//, catchNonExistentStaticRoutesMiddleware)
 
   // Requests for root files (e.g. /robots.txt or /favicon.ico) that were
   // not served statically above will also return 404

src/app/routes/.well-known/index.ts

@@ -0,0 +1,14 @@
+import express, { Router } from 'express'
+
+import { formSgSdkJwksConfig } from '../../config/features/formsg-sdk-jwks.config'
+
+export const WellKnownRouter = Router()
+
+/**
+ * Returns the FormSG's public json web key set (JWKS) for communication with FormSG SDK
+ * @route GET /.well-known/formsg/jwks.json
+ * @returns 200
+ */
+WellKnownRouter.get('/formsg/jwks.json', (req, res) => {
+  return res.send(formSgSdkJwksConfig.publicJwks)
+})