pomerium/authenticate/authenticate.go
2019-01-02 12:13:36 -08:00

254 lines
7.7 KiB
Go

package authenticate // import "github.com/pomerium/pomerium/authenticate"
import (
"encoding/base64"
"errors"
"fmt"
"html/template"
"net/url"
"strings"
"time"
"github.com/pomerium/envconfig"
"github.com/pomerium/pomerium/authenticate/providers"
"github.com/pomerium/pomerium/internal/aead"
"github.com/pomerium/pomerium/internal/sessions"
"github.com/pomerium/pomerium/internal/templates"
)
// Options permits the configuration of the authentication service
type Options struct {
// e.g.
Host string `envconfig:"HOST"`
//
ProxyClientID string `envconfig:"PROXY_CLIENT_ID"`
ProxyClientSecret string `envconfig:"PROXY_CLIENT_SECRET"`
// Coarse authorization based on user email domain
EmailDomains []string `envconfig:"SSO_EMAIL_DOMAIN"`
ProxyRootDomains []string `envconfig:"PROXY_ROOT_DOMAIN"`
// Session/Cookie management
CookieName string
CookieSecret string `envconfig:"COOKIE_SECRET"`
CookieDomain string `envconfig:"COOKIE_DOMAIN"`
CookieExpire time.Duration `envconfig:"COOKIE_EXPIRE" default:"168h"`
CookieRefresh time.Duration `envconfig:"COOKIE_REFRESH" default:"1h"`
CookieSecure bool `envconfig:"COOKIE_SECURE" default:"true"`
CookieHTTPOnly bool `envconfig:"COOKIE_HTTP_ONLY" default:"true"`
AuthCodeSecret string `envconfig:"AUTH_CODE_SECRET"`
SessionLifetimeTTL time.Duration `envconfig:"SESSION_LIFETIME_TTL" default:"720h"`
// Authentication provider configuration vars
RedirectURL *url.URL `envconfig:"IDP_REDIRECT_URL" ` // e.g. auth.example.com/oauth/callback
ClientID string `envconfig:"IDP_CLIENT_ID"` // IdP ClientID
ClientSecret string `envconfig:"IDP_CLIENT_SECRET"` // IdP Secret
Provider string `envconfig:"IDP_PROVIDER"` //Provider name e.g. "oidc","okta","google",etc
ProviderURL *url.URL `envconfig:"IDP_PROVIDER_URL"`
Scopes []string `envconfig:"IDP_SCOPE" default:"openid,email,profile"`
// todo(bdd) : can delete?`
ApprovalPrompt string `envconfig:"IDP_APPROVAL_PROMPT" default:"consent"`
RequestLogging bool `envconfig:"REQUEST_LOGGING" default:"true"`
RequestTimeout time.Duration `envconfig:"REQUEST_TIMEOUT" default:"2s"`
}
var defaultOptions = &Options{
EmailDomains: []string{"*"},
CookieName: "_pomerium_authenticate",
CookieSecure: true,
CookieHTTPOnly: true,
CookieExpire: time.Duration(168) * time.Hour,
CookieRefresh: time.Duration(1) * time.Hour,
RequestTimeout: time.Duration(2) * time.Second,
SessionLifetimeTTL: time.Duration(720) * time.Hour,
ApprovalPrompt: "consent",
Scopes: []string{"openid", "email", "profile"},
}
// OptionsFromEnvConfig builds the authentication service's configuration
// options from provided environmental variables
func OptionsFromEnvConfig() (*Options, error) {
o := defaultOptions
if err := envconfig.Process("", o); err != nil {
return nil, err
}
return o, nil
}
// Validate checks to see if configuration values are valid for authentication service.
// The checks do not modify the internal state of the Option structure. Function returns
// on first error found.
func (o *Options) Validate() error {
if o.ProviderURL == nil {
return errors.New("missing setting: identity provider url")
}
if o.RedirectURL == nil {
return errors.New("missing setting: identity provider redirect url")
}
redirectPath := "/oauth2/callback"
if o.RedirectURL.Path != redirectPath {
return fmt.Errorf("setting redirect-url was %s path should be %s", o.RedirectURL.Path, redirectPath)
}
if o.ClientID == "" {
return errors.New("missing setting: client id")
}
if o.ClientSecret == "" {
return errors.New("missing setting: client secret")
}
if len(o.EmailDomains) == 0 {
return errors.New("missing setting email domain")
}
if len(o.ProxyRootDomains) == 0 {
return errors.New("missing setting: proxy root domain")
}
if o.ProxyClientID == "" {
return errors.New("missing setting: proxy client id")
}
if o.ProxyClientSecret == "" {
return errors.New("missing setting: proxy client secret")
}
decodedCookieSecret, err := base64.StdEncoding.DecodeString(o.CookieSecret)
if err != nil {
return fmt.Errorf("authenticate options: cookie secret invalid"+
"must be a base64-encoded, 256 bit key e.g. `head -c32 /dev/urandom | base64`"+
"got %q", err)
}
validCookieSecretLength := false
for _, i := range []int{32, 64} {
if len(decodedCookieSecret) == i {
validCookieSecretLength = true
}
}
if !validCookieSecretLength {
return fmt.Errorf("authenticate options: invalid cookie secret strength want 32 to 64 bytes, got %d bytes", len(decodedCookieSecret))
}
if o.CookieRefresh >= o.CookieExpire {
return fmt.Errorf("cookie_refresh (%s) must be less than cookie_expire (%s)", o.CookieRefresh.String(), o.CookieExpire.String())
}
return nil
}
// Authenticator stores all the information associated with proxying the request.
type Authenticator struct {
Validator func(string) bool
EmailDomains []string
ProxyRootDomains []string
Host string
CookieSecure bool
ProxyClientID string
ProxyClientSecret string
SessionLifetimeTTL time.Duration
decodedCookieSecret []byte
templates *template.Template
// sesion related
csrfStore sessions.CSRFStore
sessionStore sessions.SessionStore
cipher aead.Cipher
redirectURL *url.URL
provider providers.Provider
}
// NewAuthenticator creates a Authenticator struct and applies the optional functions slice to the struct.
func NewAuthenticator(opts *Options, optionFuncs ...func(*Authenticator) error) (*Authenticator, error) {
if opts == nil {
return nil, errors.New("options cannot be nil")
}
if err := opts.Validate(); err != nil {
return nil, err
}
decodedAuthCodeSecret, err := base64.StdEncoding.DecodeString(opts.AuthCodeSecret)
if err != nil {
return nil, err
}
cipher, err := aead.NewMiscreantCipher([]byte(decodedAuthCodeSecret))
if err != nil {
return nil, err
}
decodedCookieSecret, err := base64.StdEncoding.DecodeString(opts.CookieSecret)
if err != nil {
return nil, err
}
cookieStore, err := sessions.NewCookieStore(opts.CookieName,
sessions.CreateMiscreantCookieCipher(decodedCookieSecret),
func(c *sessions.CookieStore) error {
c.CookieDomain = opts.CookieDomain
c.CookieHTTPOnly = opts.CookieHTTPOnly
c.CookieExpire = opts.CookieExpire
c.CookieSecure = opts.CookieSecure
return nil
})
if err != nil {
return nil, err
}
p := &Authenticator{
ProxyClientID: opts.ProxyClientID,
ProxyClientSecret: opts.ProxyClientSecret,
EmailDomains: opts.EmailDomains,
ProxyRootDomains: dotPrependDomains(opts.ProxyRootDomains),
CookieSecure: opts.CookieSecure,
redirectURL: opts.RedirectURL,
templates: templates.New(),
csrfStore: cookieStore,
sessionStore: cookieStore,
cipher: cipher,
}
// p.ServeMux = p.Handler()
p.provider, err = newProvider(opts)
if err != nil {
return nil, err
}
// apply the option functions
for _, optFunc := range optionFuncs {
err := optFunc(p)
if err != nil {
return nil, err
}
}
return p, nil
}
func newProvider(opts *Options) (providers.Provider, error) {
pd := &providers.ProviderData{
RedirectURL: opts.RedirectURL,
ProviderName: opts.Provider,
ClientID: opts.ClientID,
ClientSecret: opts.ClientSecret,
ApprovalPrompt: opts.ApprovalPrompt,
SessionLifetimeTTL: opts.SessionLifetimeTTL,
ProviderURL: opts.ProviderURL,
Scopes: opts.Scopes,
}
np, err := providers.New(opts.Provider, pd)
if err != nil {
return nil, err
}
return providers.NewSingleFlightProvider(np), nil
}
func dotPrependDomains(d []string) []string {
for i := range d {
if d[i] != "" && !strings.HasPrefix(d[i], ".") {
d[i] = fmt.Sprintf(".%s", d[i])
}
}
return d
}