theikkila-jwks-rsa
v1.2.0
Published
Library to retrieve RSA public keys from a JWKS endpoint
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jwks-rsa
A library to retrieve RSA signing keys from a JWKS (JSON Web Key Set) endpoint.
npm install --save jwks-rsa
Usage
You'll provide the client with the JWKS endpoint which exposes your signing keys. Using the getSigningKey
you can then get the signing key that matches a specific kid
.
const jwksClient = require('jwks-rsa');
const client = jwksClient({
strictSsl: true, // Default value
jwksUri: 'https://sandrino.auth0.com/.well-known/jwks.json'
});
const kid = 'RkI5MjI5OUY5ODc1N0Q4QzM0OUYzNkVGMTJDOUEzQkFCOTU3NjE2Rg';
client.getSigningKey(kid, (err, key) => {
const signingKey = key.publicKey || key.rsaPublicKey;
// Now I can use this to configure my Express or Hapi middleware
});
Integrations are also provided with:
Caching
In order to prevent a call to be made each time a signing key needs to be retrieved you can also configure a cache as follows. If a signing key matching the kid
is found, this will be cached and the next time this kid
is requested the signing key will be served from the cache instead of calling back to the JWKS endpoint.
const jwksClient = require('jwks-rsa');
const client = jwksClient({
cache: true,
cacheMaxEntries: 5, // Default value
cacheMaxAge: ms('10h'), // Default value
jwksUri: 'https://sandrino.auth0.com/.well-known/jwks.json'
});
const kid = 'RkI5MjI5OUY5ODc1N0Q4QzM0OUYzNkVGMTJDOUEzQkFCOTU3NjE2Rg';
client.getSigningKey(kid, (err, key) => {
const signingKey = key.publicKey || key.rsaPublicKey;
// Now I can use this to configure my Express or Hapi middleware
});
Rate Limiting
Even if caching is enabled the library will call the JWKS endpoint if the kid
is not available in the cache, because a key rotation could have taken place. To prevent attackers to send many random kid
s you can also configure rate limiting. This will allow you to limit the number of calls that are made to the JWKS endpoint per minute (because it would be highly unlikely that signing keys are rotated multiple times per minute).
const jwksClient = require('jwks-rsa');
const client = jwksClient({
cache: true,
rateLimit: true,
jwksRequestsPerMinute: 10, // Default value
jwksUri: 'https://sandrino.auth0.com/.well-known/jwks.json'
});
const kid = 'RkI5MjI5OUY5ODc1N0Q4QzM0OUYzNkVGMTJDOUEzQkFCOTU3NjE2Rg';
client.getSigningKey(kid, (err, key) => {
const signingKey = key.publicKey || key.rsaPublicKey;
// Now I can use this to configure my Express or Hapi middleware
});
Running Tests
npm run test
Showing Trace Logs
To show trace logs you can set the following environment variable:
DEBUG=jwks
Output:
jwks Retrieving keys from http://my-authz-server/.well-known/jwks.json +5ms
jwks Keys: +8ms [ { alg: 'RS256',
kty: 'RSA',
use: 'sig',
x5c: [ 'pk1' ],
kid: 'ABC' },
{ alg: 'RS256', kty: 'RSA', use: 'sig', x5c: [], kid: '123' } ]