dex/vendor/github.com/coreos/go-oidc/oidc.go
2016-12-01 13:16:14 -08:00

299 lines
7.9 KiB
Go

// Package oidc implements OpenID Connect client logic for the golang.org/x/oauth2 package.
package oidc
import (
"encoding/json"
"errors"
"fmt"
"io/ioutil"
"net/http"
"strings"
"time"
"golang.org/x/net/context"
"golang.org/x/net/context/ctxhttp"
"golang.org/x/oauth2"
jose "gopkg.in/square/go-jose.v2"
)
const (
// ScopeOpenID is the mandatory scope for all OpenID Connect OAuth2 requests.
ScopeOpenID = "openid"
// ScopeOfflineAccess is an optional scope defined by OpenID Connect for requesting
// OAuth2 refresh tokens.
//
// Support for this scope differs between OpenID Connect providers. For instance
// Google rejects it, favoring appending "access_type=offline" as part of the
// authorization request instead.
//
// See: https://openid.net/specs/openid-connect-core-1_0.html#OfflineAccess
ScopeOfflineAccess = "offline_access"
)
// ClientContext returns a new Context that carries the provided HTTP client.
//
// This method sets the same context key used by the golang.org/x/oauth2 package,
// so the returned context works for that package too.
//
// myClient := &http.Client{}
// ctx := oidc.ClientContext(parentContext, myClient)
//
// // This will use the custom client
// provider, err := oidc.NewProvider(ctx, "https://accounts.example.com")
//
func ClientContext(ctx context.Context, client *http.Client) context.Context {
return context.WithValue(ctx, oauth2.HTTPClient, client)
}
func clientFromContext(ctx context.Context) *http.Client {
if client, ok := ctx.Value(oauth2.HTTPClient).(*http.Client); ok {
return client
}
return http.DefaultClient
}
// Provider represents an OpenID Connect server's configuration.
type Provider struct {
issuer string
authURL string
tokenURL string
userInfoURL string
// Raw claims returned by the server.
rawClaims []byte
remoteKeySet *remoteKeySet
}
type cachedKeys struct {
keys []jose.JSONWebKey
expiry time.Time
}
type providerJSON struct {
Issuer string `json:"issuer"`
AuthURL string `json:"authorization_endpoint"`
TokenURL string `json:"token_endpoint"`
JWKSURL string `json:"jwks_uri"`
UserInfoURL string `json:"userinfo_endpoint"`
}
// NewProvider uses the OpenID Connect discovery mechanism to construct a Provider.
//
// The issuer is the URL identifier for the service. For example: "https://accounts.google.com"
// or "https://login.salesforce.com".
func NewProvider(ctx context.Context, issuer string) (*Provider, error) {
wellKnown := strings.TrimSuffix(issuer, "/") + "/.well-known/openid-configuration"
resp, err := ctxhttp.Get(ctx, clientFromContext(ctx), wellKnown)
if err != nil {
return nil, err
}
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%s: %s", resp.Status, body)
}
defer resp.Body.Close()
var p providerJSON
if err := json.Unmarshal(body, &p); err != nil {
return nil, fmt.Errorf("oidc: failed to decode provider discovery object: %v", err)
}
if p.Issuer != issuer {
return nil, fmt.Errorf("oidc: issuer did not match the issuer returned by provider, expected %q got %q", issuer, p.Issuer)
}
return &Provider{
issuer: p.Issuer,
authURL: p.AuthURL,
tokenURL: p.TokenURL,
userInfoURL: p.UserInfoURL,
rawClaims: body,
remoteKeySet: newRemoteKeySet(ctx, p.JWKSURL, time.Now),
}, nil
}
// Claims unmarshals raw fields returned by the server during discovery.
//
// var claims struct {
// ScopesSupported []string `json:"scopes_supported"`
// ClaimsSupported []string `json:"claims_supported"`
// }
//
// if err := provider.Claims(&claims); err != nil {
// // handle unmarshaling error
// }
//
// For a list of fields defined by the OpenID Connect spec see:
// https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
func (p *Provider) Claims(v interface{}) error {
if p.rawClaims == nil {
return errors.New("oidc: claims not set")
}
return json.Unmarshal(p.rawClaims, v)
}
// Endpoint returns the OAuth2 auth and token endpoints for the given provider.
func (p *Provider) Endpoint() oauth2.Endpoint {
return oauth2.Endpoint{AuthURL: p.authURL, TokenURL: p.tokenURL}
}
// UserInfo represents the OpenID Connect userinfo claims.
type UserInfo struct {
Subject string `json:"sub"`
Profile string `json:"profile"`
Email string `json:"email"`
EmailVerified bool `json:"email_verified"`
claims []byte
}
// Claims unmarshals the raw JSON object claims into the provided object.
func (u *UserInfo) Claims(v interface{}) error {
if u.claims == nil {
return errors.New("oidc: claims not set")
}
return json.Unmarshal(u.claims, v)
}
// UserInfo uses the token source to query the provider's user info endpoint.
func (p *Provider) UserInfo(ctx context.Context, tokenSource oauth2.TokenSource) (*UserInfo, error) {
if p.userInfoURL == "" {
return nil, errors.New("oidc: user info endpoint is not supported by this provider")
}
req, err := http.NewRequest("GET", p.userInfoURL, nil)
if err != nil {
return nil, fmt.Errorf("oidc: create GET request: %v", err)
}
token, err := tokenSource.Token()
if err != nil {
return nil, fmt.Errorf("oidc: get access token: %v", err)
}
token.SetAuthHeader(req)
resp, err := ctxhttp.Do(ctx, clientFromContext(ctx), req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
if resp.StatusCode != http.StatusOK {
return nil, fmt.Errorf("%s: %s", resp.Status, body)
}
var userInfo UserInfo
if err := json.Unmarshal(body, &userInfo); err != nil {
return nil, fmt.Errorf("oidc: failed to decode userinfo: %v", err)
}
userInfo.claims = body
return &userInfo, nil
}
// IDToken is an OpenID Connect extension that provides a predictable representation
// of an authorization event.
//
// The ID Token only holds fields OpenID Connect requires. To access additional
// claims returned by the server, use the Claims method.
type IDToken struct {
// The URL of the server which issued this token. This will always be the same
// as the URL used for initial discovery.
Issuer string
// The client, or set of clients, that this token is issued for.
Audience []string
// A unique string which identifies the end user.
Subject string
IssuedAt time.Time
Expiry time.Time
Nonce string
// Raw payload of the id_token.
claims []byte
}
// Claims unmarshals the raw JSON payload of the ID Token into a provided struct.
//
// idToken, err := idTokenVerifier.Verify(rawIDToken)
// if err != nil {
// // handle error
// }
// var claims struct {
// Email string `json:"email"`
// EmailVerified bool `json:"email_verified"`
// }
// if err := idToken.Claims(&claims); err != nil {
// // handle error
// }
//
func (i *IDToken) Claims(v interface{}) error {
if i.claims == nil {
return errors.New("oidc: claims not set")
}
return json.Unmarshal(i.claims, v)
}
type idToken struct {
Issuer string `json:"iss"`
Subject string `json:"sub"`
Audience audience `json:"aud"`
Expiry jsonTime `json:"exp"`
IssuedAt jsonTime `json:"iat"`
Nonce string `json:"nonce"`
}
type audience []string
func (a *audience) UnmarshalJSON(b []byte) error {
var s string
if json.Unmarshal(b, &s) == nil {
*a = audience{s}
return nil
}
var auds []string
if err := json.Unmarshal(b, &auds); err != nil {
return err
}
*a = audience(auds)
return nil
}
func (a audience) MarshalJSON() ([]byte, error) {
if len(a) == 1 {
return json.Marshal(a[0])
}
return json.Marshal([]string(a))
}
type jsonTime time.Time
func (j *jsonTime) UnmarshalJSON(b []byte) error {
var n json.Number
if err := json.Unmarshal(b, &n); err != nil {
return err
}
var unix int64
if t, err := n.Int64(); err == nil {
unix = t
} else {
f, err := n.Float64()
if err != nil {
return err
}
unix = int64(f)
}
*j = jsonTime(time.Unix(unix, 0))
return nil
}
func (j jsonTime) MarshalJSON() ([]byte, error) {
return json.Marshal(time.Time(j).Unix())
}