From e7d5a6073c232d9084eaaac609e7873d6bb788c1 Mon Sep 17 00:00:00 2001
From: Trong Huu Nguyen <trong.huu.nguyen@nav.no>
Date: Sat, 16 Oct 2021 10:28:49 +0200
Subject: [PATCH] refactor: add jwks pkg for generating jwk sets

---
 pkg/jwks/jwks.go | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 pkg/jwks/jwks.go

diff --git a/pkg/jwks/jwks.go b/pkg/jwks/jwks.go
new file mode 100644
index 0000000..c285417
--- /dev/null
+++ b/pkg/jwks/jwks.go
@@ -0,0 +1,49 @@
+package jwks
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+
+	"github.com/lestrrat-go/jwx/jwa"
+	"github.com/lestrrat-go/jwx/jwk"
+)
+
+type Pair struct {
+	Private jwk.Set
+	Public  jwk.Set
+}
+
+func NewJwksPair() (*Pair, error) {
+	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		return nil, err
+	}
+
+	key, err := jwk.New(privateKey)
+	if err != nil {
+		return nil, err
+	}
+
+	err = jwk.AssignKeyID(key)
+	if err != nil {
+		return nil, err
+	}
+
+	err = key.Set(jwk.AlgorithmKey, jwa.RS256)
+	if err != nil {
+		return nil, err
+	}
+
+	privateKeys := jwk.NewSet()
+	privateKeys.Add(key)
+
+	publicKeys, err := jwk.PublicSetOf(privateKeys)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Pair{
+		Private: privateKeys,
+		Public:  publicKeys,
+	}, nil
+}