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dex/connector/openshift/openshift.go
2020-02-21 16:53:46 +01:00

256 lines
6.8 KiB
Go

package openshift
import (
"context"
"crypto/tls"
"crypto/x509"
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"strings"
"time"
"github.com/dexidp/dex/connector"
"github.com/dexidp/dex/pkg/groups"
"github.com/dexidp/dex/pkg/log"
"github.com/dexidp/dex/storage/kubernetes/k8sapi"
"golang.org/x/oauth2"
)
// Config holds configuration options for OpenShift login
type Config struct {
Issuer string `json:"issuer"`
ClientID string `json:"clientID"`
ClientSecret string `json:"clientSecret"`
RedirectURI string `json:"redirectURI"`
Groups []string `json:"groups"`
InsecureCA bool `json:"insecureCA"`
RootCA string `json:"rootCA"`
}
var (
_ connector.CallbackConnector = (*openshiftConnector)(nil)
)
type openshiftConnector struct {
apiURL string
redirectURI string
clientID string
clientSecret string
cancel context.CancelFunc
logger log.Logger
httpClient *http.Client
oauth2Config *oauth2.Config
insecureCA bool
rootCA string
groups []string
}
type user struct {
k8sapi.TypeMeta `json:",inline"`
k8sapi.ObjectMeta `json:"metadata,omitempty"`
Identities []string `json:"identities" protobuf:"bytes,3,rep,name=identities"`
FullName string `json:"fullName,omitempty" protobuf:"bytes,2,opt,name=fullName"`
Groups []string `json:"groups" protobuf:"bytes,4,rep,name=groups"`
}
// Open returns a connector which can be used to login users through an upstream
// OpenShift OAuth2 provider.
func (c *Config) Open(id string, logger log.Logger) (conn connector.Connector, err error) {
ctx, cancel := context.WithCancel(context.Background())
wellKnownURL := strings.TrimSuffix(c.Issuer, "/") + "/.well-known/oauth-authorization-server"
req, err := http.NewRequest(http.MethodGet, wellKnownURL, nil)
openshiftConnector := openshiftConnector{
apiURL: c.Issuer,
cancel: cancel,
clientID: c.ClientID,
clientSecret: c.ClientSecret,
insecureCA: c.InsecureCA,
logger: logger,
redirectURI: c.RedirectURI,
rootCA: c.RootCA,
groups: c.Groups,
}
if openshiftConnector.httpClient, err = newHTTPClient(c.InsecureCA, c.RootCA); err != nil {
cancel()
return nil, fmt.Errorf("failed to create HTTP client: %v", err)
}
var metadata struct {
Auth string `json:"authorization_endpoint"`
Token string `json:"token_endpoint"`
}
resp, err := openshiftConnector.httpClient.Do(req.WithContext(ctx))
if err != nil {
cancel()
return nil, fmt.Errorf("failed to query OpenShift endpoint %v", err)
}
defer resp.Body.Close()
if err := json.NewDecoder(resp.Body).Decode(&metadata); err != nil {
cancel()
return nil, fmt.Errorf("discovery through endpoint %s failed to decode body: %v",
wellKnownURL, err)
}
openshiftConnector.oauth2Config = &oauth2.Config{
ClientID: c.ClientID,
ClientSecret: c.ClientSecret,
Endpoint: oauth2.Endpoint{
AuthURL: metadata.Auth, TokenURL: metadata.Token,
},
Scopes: []string{"user:info"},
RedirectURL: c.RedirectURI,
}
return &openshiftConnector, nil
}
func (c *openshiftConnector) Close() error {
c.cancel()
return nil
}
// LoginURL returns the URL to redirect the user to login with.
func (c *openshiftConnector) LoginURL(scopes connector.Scopes, callbackURL, state string) (string, error) {
if c.redirectURI != callbackURL {
return "", fmt.Errorf("expected callback URL %q did not match the URL in the config %q", callbackURL, c.redirectURI)
}
return c.oauth2Config.AuthCodeURL(state), nil
}
type oauth2Error struct {
error string
errorDescription string
}
func (e *oauth2Error) Error() string {
if e.errorDescription == "" {
return e.error
}
return e.error + ": " + e.errorDescription
}
// HandleCallback parses the request and returns the user's identity
func (c *openshiftConnector) HandleCallback(s connector.Scopes, r *http.Request) (identity connector.Identity, err error) {
q := r.URL.Query()
if errType := q.Get("error"); errType != "" {
return identity, &oauth2Error{errType, q.Get("error_description")}
}
ctx := r.Context()
if c.httpClient != nil {
ctx = context.WithValue(r.Context(), oauth2.HTTPClient, c.httpClient)
}
token, err := c.oauth2Config.Exchange(ctx, q.Get("code"))
if err != nil {
return identity, fmt.Errorf("oidc: failed to get token: %v", err)
}
client := c.oauth2Config.Client(ctx, token)
user, err := c.user(ctx, client)
if err != nil {
return identity, fmt.Errorf("openshift: get user: %v", err)
}
if len(c.groups) > 0 {
validGroups := validateAllowedGroups(user.Groups, c.groups)
if !validGroups {
return identity, fmt.Errorf("openshift: user %q is not in any of the required groups", user.Name)
}
}
identity = connector.Identity{
UserID: user.UID,
Username: user.Name,
PreferredUsername: user.Name,
Email: user.Name,
Groups: user.Groups,
}
return identity, nil
}
// user function returns the OpenShift user associated with the authenticated user
func (c *openshiftConnector) user(ctx context.Context, client *http.Client) (u user, err error) {
url := c.apiURL + "/apis/user.openshift.io/v1/users/~"
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return u, fmt.Errorf("new req: %v", err)
}
resp, err := client.Do(req.WithContext(ctx))
if err != nil {
return u, fmt.Errorf("get URL %v", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return u, fmt.Errorf("read body: %v", err)
}
return u, fmt.Errorf("%s: %s", resp.Status, body)
}
if err := json.NewDecoder(resp.Body).Decode(&u); err != nil {
return u, fmt.Errorf("JSON decode: %v", err)
}
return u, err
}
func validateAllowedGroups(userGroups, allowedGroups []string) bool {
matchingGroups := groups.Filter(userGroups, allowedGroups)
return len(matchingGroups) != 0
}
// newHTTPClient returns a new HTTP client
func newHTTPClient(insecureCA bool, rootCA string) (*http.Client, error) {
tlsConfig := tls.Config{}
if insecureCA {
tlsConfig = tls.Config{InsecureSkipVerify: true}
} else if rootCA != "" {
tlsConfig := tls.Config{RootCAs: x509.NewCertPool()}
rootCABytes, err := ioutil.ReadFile(rootCA)
if err != nil {
return nil, fmt.Errorf("failed to read root-ca: %v", err)
}
if !tlsConfig.RootCAs.AppendCertsFromPEM(rootCABytes) {
return nil, fmt.Errorf("no certs found in root CA file %q", rootCA)
}
}
return &http.Client{
Transport: &http.Transport{
TLSClientConfig: &tlsConfig,
Proxy: http.ProxyFromEnvironment,
DialContext: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).DialContext,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
},
}, nil
}