feat: add jwks support (#407)

migrations/multitenant/0006-add-jwks-column.sql

@@ -0,0 +1 @@
+ALTER TABLE tenants ADD COLUMN IF NOT EXISTS jwks jsonb DEFAULT NULL;

package.json

@@ -51,7 +51,7 @@
     "fs-extra": "^10.0.1",
     "fs-xattr": "^0.3.1",
     "ioredis": "^5.2.4",
-    "jsonwebtoken": "^9.0.0",
+    "jsonwebtoken": "^9.0.2",
     "knex": "^2.4.2",
     "md5-file": "^5.0.0",
     "pg": "^8.10.0",
@@ -69,7 +69,7 @@
     "@types/fs-extra": "^9.0.13",
     "@types/jest": "^29.2.1",
     "@types/js-yaml": "^4.0.5",
-    "@types/jsonwebtoken": "^8.5.8",
+    "@types/jsonwebtoken": "^9.0.5",
     "@types/mustache": "^4.2.2",
     "@types/node": "^18.14.6",
     "@types/pg": "^8.6.4",

src/auth/jwt.ts

@@ -1,7 +1,15 @@
+import * as crypto from 'crypto'
 import jwt from 'jsonwebtoken'
+
+import { getJwtSecret as getJwtSecretForTenant } from '../database/tenant'
 import { getConfig } from '../config'
 
-const { jwtAlgorithm } = getConfig()
+const { isMultitenant, jwtSecret, jwtAlgorithm, jwtJWKS } = getConfig()
+
+const JWT_HMAC_ALGOS: jwt.Algorithm[] = ['HS256', 'HS384', 'HS512']
+const JWT_RSA_ALGOS: jwt.Algorithm[] = ['RS256', 'RS384', 'RS512']
+const JWT_ECC_ALGOS: jwt.Algorithm[] = ['ES256', 'ES384', 'ES512']
+const JWT_ED_ALGOS: jwt.Algorithm[] = ['EdDSA'] as unknown as jwt.Algorithm[] // types for EdDSA not yet updated
 
 interface jwtInterface {
   sub?: string
@@ -20,17 +28,128 @@ export type SignedUploadToken = {
   exp: number
 }
 
+export function findJWKFromHeader(
+  header: jwt.JwtHeader,
+  secret: string,
+  jwks: { keys: { kid?: string; kty: string }[] } | null
+) {
+  if (!jwks || !jwks.keys) {
+    return secret
+  }
+
+  if (JWT_HMAC_ALGOS.indexOf(header.alg as jwt.Algorithm) > -1) {
+    // JWT is using HS, find the proper key
+
+    if (!header.kid && header.alg === jwtAlgorithm) {
+      // jwt is probably signed with the static secret
+      return secret
+    }
+
+    // find the first key without a kid or with the matching kid and the "oct" type
+    const jwk = jwks.keys.find(
+      (key) => (!key.kid || key.kid === header.kid) && key.kty === 'oct' && (key as any).k
+    )
+
+    if (!jwk) {
+      // jwt is probably signed with the static secret
+      return secret
+    }
+
+    return Buffer.from((jwk as any).k, 'base64')
+  }
+
+  // jwt is using an asymmetric algorithm
+  let kty = 'RSA'
+
+  if (JWT_ECC_ALGOS.indexOf(header.alg as jwt.Algorithm) > -1) {
+    kty = 'EC'
+  } else if (JWT_ED_ALGOS.indexOf(header.alg as jwt.Algorithm) > -1) {
+    kty = 'OKP'
+  }
+
+  // find the first key with a matching kid (or no kid if none is specified in the JWT header) and the correct key type
+  const jwk = jwks.keys.find((key) => {
+    return ((!key.kid && !header.kid) || key.kid === header.kid) && key.kty === kty
+  })
+
+  if (!jwk) {
+    // couldn't find a matching JWK, try to use the secret
+    return secret
+  }
+
+  return crypto.createPublicKey({
+    format: 'jwk',
+    key: jwk,
+  })
+}
+
+function getJWTVerificationKey(
+  secret: string,
+  jwks: { keys: { kid?: string; kty: string }[] } | null
+): jwt.GetPublicKeyOrSecret {
+  return (header: jwt.JwtHeader, callback: jwt.SigningKeyCallback) => {
+    let result: any = null
+
+    try {
+      result = findJWKFromHeader(header, secret, jwks)
+    } catch (e: any) {
+      callback(e)
+      return
+    }
+
+    callback(null, result)
+  }
+}
+
+export function getJWTAlgorithms(
+  secret: string,
+  jwks: { keys: { kid?: string; kty: string }[] } | null
+) {
+  let algorithms: jwt.Algorithm[]
+
+  if (jwks && jwks.keys && jwks.keys.length) {
+    const hasRSA = jwks.keys.find((key) => key.kty === 'RSA')
+    const hasECC = jwks.keys.find((key) => key.kty === 'EC')
+    const hasED = jwks.keys.find(
+      (key) => key.kty === 'OKP' && ((key as any).crv === 'Ed25519' || (key as any).crv === 'Ed448')
+    )
+    const hasHS = jwks.keys.find((key) => key.kty === 'oct' && (key as any).k)
+
+    algorithms = [
+      jwtAlgorithm as jwt.Algorithm,
+      ...(hasRSA ? JWT_RSA_ALGOS : []),
+      ...(hasECC ? JWT_ECC_ALGOS : []),
+      ...(hasED ? JWT_ED_ALGOS : []),
+      ...(hasHS ? JWT_HMAC_ALGOS : []),
+    ]
+  } else {
+    algorithms = [jwtAlgorithm as jwt.Algorithm]
+  }
+
+  return algorithms
+}
+
 /**
  * Verifies if a JWT is valid
  * @param token
  * @param secret
+ * @param jwks
  */
-export function verifyJWT<T>(token: string, secret: string): Promise<jwt.JwtPayload & T> {
+export function verifyJWT<T>(
+  token: string,
+  secret: string,
+  jwks?: { keys: { kid?: string; kty: string }[] } | null
+): Promise<jwt.JwtPayload & T> {
   return new Promise((resolve, reject) => {
-    jwt.verify(token, secret, { algorithms: [jwtAlgorithm as jwt.Algorithm] }, (err, decoded) => {
-      if (err) return reject(err)
-      resolve(decoded as jwt.JwtPayload & T)
-    })
+    jwt.verify(
+      token,
+      getJWTVerificationKey(secret, jwks || null),
+      { algorithms: getJWTAlgorithms(secret, jwks || null) },
+      (err, decoded) => {
+        if (err) return reject(err)
+        resolve(decoded as jwt.JwtPayload & T)
+      }
+    )
   })
 }
 
@@ -62,13 +181,13 @@ export function signJWT(
  * Extract the owner (user) from the provided JWT
  * @param token
  * @param secret
+ * @param jwks
  */
-export async function getOwner(token: string, secret: string): Promise<string | undefined> {
-  const decodedJWT = await verifyJWT(token, secret)
+export async function getOwner(
+  token: string,
+  secret: string,
+  jwks: { keys: { kid?: string; kty: string }[] } | null
+): Promise<string | undefined> {
+  const decodedJWT = await verifyJWT(token, secret, jwks)
   return (decodedJWT as jwtInterface)?.sub
 }
-
-export async function getRole(token: string, secret: string): Promise<string | undefined> {
-  const decodedJWT = await verifyJWT(token, secret)
-  return (decodedJWT as jwtInterface)?.role
-}