ContainerImage.Pinniped/internal/oidc/dynamiccodec/codec.go

59 lines
1.8 KiB
Go

// Copyright 2020 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
// Package dynamiccodec provides a type that can encode information using a just-in-time signing and
// (optionally) encryption secret.
package dynamiccodec
import (
"time"
"github.com/gorilla/securecookie"
"go.pinniped.dev/internal/oidc"
)
var _ oidc.Codec = &Codec{}
// KeyFunc returns a single key: a symmetric key.
type KeyFunc func() []byte
// Codec can dynamically encode and decode information by using a KeyFunc to get its keys
// just-in-time.
type Codec struct {
lifespan time.Duration
signingKeyFunc KeyFunc
encryptionKeyFunc KeyFunc
}
// New creates a new Codec that will use the provided keyFuncs for its key source, and
// use the securecookie.JSONEncoder. The securecookie.JSONEncoder is used because the default
// securecookie.GobEncoder is less compact and more difficult to make forward compatible.
//
// The returned Codec will make ensure that the encoded values will only be valid for the provided
// lifespan.
func New(lifespan time.Duration, signingKeyFunc, encryptionKeyFunc KeyFunc) *Codec {
return &Codec{
lifespan: lifespan,
signingKeyFunc: signingKeyFunc,
encryptionKeyFunc: encryptionKeyFunc,
}
}
// Encode implements oidc.Encode().
func (c *Codec) Encode(name string, value interface{}) (string, error) {
return c.delegate().Encode(name, value)
}
// Decode implements oidc.Decode().
func (c *Codec) Decode(name string, value string, into interface{}) error {
return c.delegate().Decode(name, value, into)
}
func (c *Codec) delegate() *securecookie.SecureCookie {
codec := securecookie.New(c.signingKeyFunc(), c.encryptionKeyFunc())
codec.MaxAge(int(c.lifespan.Seconds()))
codec.SetSerializer(securecookie.JSONEncoder{})
return codec
}