JWK 
Package jwk implements JWK as described in RFC7517. If you are looking to use JWT wit JWKs, look no further than github.com/lestrrat-go/jwx.
- Parse and work with RSA/EC/Symmetric/OKP JWK types
- Convert to and from JSON
- Convert to and from raw key types (e.g. *rsa.PrivateKey)
- Ability to keep a JWKS fresh using *jwk.AutoRefresh
Supported key types:
| kty | Curve | Go Key Type |
|---|---|---|
| RSA | N/A | rsa.PrivateKey / rsa.PublicKey (2) |
| EC | P-256 P-384 P-521 secp256k1 (1) |
ecdsa.PrivateKey / ecdsa.PublicKey (2) |
| oct | N/A | []byte |
| OKP | Ed25519 (1) | ed25519.PrivateKey / ed25519.PublicKey (2) |
| X25519 (1) | (jwx/)x25519.PrivateKey / x25519.PublicKey (2) |
- Note 1: Experimental
- Note 2: Either value or pointers accepted (e.g. rsa.PrivateKey or *rsa.PrivateKey)
Documentation
Please read the API reference, or the how-to style documentation on how to use JWK can be found in the docs directory.
Auto-Refresh a key during a long-running process
package examples_test
import (
"context"
"fmt"
"time"
"github.com/lestrrat-go/httprc/v3"
"github.com/lestrrat-go/jwx/v3/jwk"
)
func Example_jwk_cache() {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
const googleCerts = `https://www.googleapis.com/oauth2/v3/certs`
// First, set up the `jwk.Cache` object. You need to pass it a
// `context.Context` object to control the lifecycle of the background fetching goroutine.
c, err := jwk.NewCache(ctx, httprc.NewClient())
if err != nil {
fmt.Printf("failed to create cache: %s\n", err)
return
}
// Tell *jwk.Cache that we only want to refresh this JWKS periodically.
if err := c.Register(ctx, googleCerts); err != nil {
fmt.Printf("failed to register google JWKS: %s\n", err)
return
}
// Pretend that this is your program's main loop
MAIN:
for {
select {
case <-ctx.Done():
break MAIN
default:
}
keyset, err := c.Lookup(ctx, googleCerts)
if err != nil {
fmt.Printf("failed to fetch google JWKS: %s\n", err)
return
}
_ = keyset
// The returned `keyset` will always be "reasonably" new.
//
// By "reasonably" we mean that we cannot guarantee that the keys will be refreshed
// immediately after it has been rotated in the remote source. But it should be close\
// enough, and should you need to forcefully refresh the token using the `(jwk.Cache).Refresh()` method.
//
// If refetching the keyset fails, a cached version will be returned from the previous
// successful sync
// Do interesting stuff with the keyset... but here, we just
// sleep for a bit
time.Sleep(time.Second)
// Because we're a dummy program, we just cancel the loop now.
// If this were a real program, you presumably loop forever
cancel()
}
// OUTPUT:
}
source: examples/jwk_cache_example_test.go
Parse and use a JWK key:
package examples_test
import (
"context"
"fmt"
"log"
"github.com/lestrrat-go/jwx/v3/internal/json"
"github.com/lestrrat-go/jwx/v3/jwk"
)
func Example_jwk_usage() {
// Use jwk.Cache if you intend to keep reuse the JWKS over and over
set, err := jwk.Fetch(context.Background(), "https://www.googleapis.com/oauth2/v3/certs")
if err != nil {
log.Printf("failed to parse JWK: %s", err)
return
}
// Key sets can be serialized back to JSON
{
jsonbuf, err := json.Marshal(set)
if err != nil {
log.Printf("failed to marshal key set into JSON: %s", err)
return
}
log.Printf("%s", jsonbuf)
}
for i := 0; i < set.Len(); i++ {
var rawkey any // This is where we would like to store the raw key, like *rsa.PrivateKey or *ecdsa.PrivateKey
key, ok := set.Key(i) // This retrieves the corresponding jwk.Key
if !ok {
log.Printf("failed to get key at index %d", i)
return
}
// jws and jwe operations can be performed using jwk.Key, but you could also
// covert it to their "raw" forms, such as *rsa.PrivateKey or *ecdsa.PrivateKey
if err := jwk.Export(key, &rawkey); err != nil {
log.Printf("failed to create public key: %s", err)
return
}
_ = rawkey
// You can create jwk.Key from a raw key, too
fromRawKey, err := jwk.Import(rawkey)
if err != nil {
log.Printf("failed to acquire raw key from jwk.Key: %s", err)
return
}
// Keys can be serialized back to JSON
jsonbuf, err := json.Marshal(key)
if err != nil {
log.Printf("failed to marshal key into JSON: %s", err)
return
}
fromJSONKey, err := jwk.Parse(jsonbuf)
if err != nil {
log.Printf("failed to parse json: %s", err)
return
}
_ = fromJSONKey
_ = fromRawKey
}
// OUTPUT:
}
//nolint:govet
func Example_jwk_marshal_json() {
// JWKs that inherently involve randomness such as RSA and EC keys are
// not used in this example, because they may produce different results
// depending on the environment.
//
// (In fact, even if you use a static source of randomness, tests may fail
// because of internal changes in the Go runtime).
raw := []byte("01234567890123456789012345678901234567890123456789ABCDEF")
// This would create a symmetric key
key, err := jwk.Import(raw)
if err != nil {
fmt.Printf("failed to create symmetric key: %s\n", err)
return
}
if _, ok := key.(jwk.SymmetricKey); !ok {
fmt.Printf("expected jwk.SymmetricKey, got %T\n", key)
return
}
key.Set(jwk.KeyIDKey, "mykey")
buf, err := json.MarshalIndent(key, "", " ")
if err != nil {
fmt.Printf("failed to marshal key into JSON: %s\n", err)
return
}
fmt.Printf("%s\n", buf)
// OUTPUT:
// {
// "k": "MDEyMzQ1Njc4OTAxMjM0NTY3ODkwMTIzNDU2Nzg5MDEyMzQ1Njc4OTAxMjM0NTY3ODlBQkNERUY",
// "kid": "mykey",
// "kty": "oct"
// }
}
source: examples/jwk_example_test.go