dex/connector/connector_ldap.go
Frode Nordahl 4d970d5fc4 connector: add LDAP connector
Authentication is performed by binding to the configured LDAP server using
the user supplied credentials. Successfull bind equals authenticated user.

Optionally the connector can be configured to search before authentication.
The entryDN found will be used to bind to the LDAP server.

This feature must be enabled to get supplementary information from the
directory (ID, Name, Email). This feature can also be used to limit access
to the service.

Example use case: Allow your users to log in with e-mail address instead of
the identification string in your DNs (typically username).

To make re-use of HTTP form handling code from the Local connector possible:
- Implemented IdentityProvider interface
- Moved the re-used functions to login_local.go

Fixes #119
2016-02-11 18:30:16 +01:00

339 lines
8.6 KiB
Go

package connector
import (
"crypto/tls"
"crypto/x509"
"fmt"
"html/template"
"io/ioutil"
"net/http"
"net/url"
"path"
"strings"
"time"
"github.com/coreos/dex/pkg/log"
"github.com/coreos/go-oidc/oidc"
"gopkg.in/ldap.v2"
)
const (
LDAPConnectorType = "ldap"
LDAPLoginPageTemplateName = "ldap-login.html"
)
func init() {
RegisterConnectorConfigType(LDAPConnectorType, func() ConnectorConfig { return &LDAPConnectorConfig{} })
}
type LDAPConnectorConfig struct {
ID string `json:"id"`
ServerHost string `json:"serverHost"`
ServerPort uint16 `json:"serverPort"`
Timeout time.Duration `json:"timeout"`
UseTLS bool `json:"useTLS"`
UseSSL bool `json:"useSSL"`
CertFile string `json:"certFile"`
KeyFile string `json:"keyFile"`
CaFile string `json:"caFile"`
SkipCertVerification bool `json:"skipCertVerification"`
BaseDN string `json:"baseDN"`
NameAttribute string `json:"nameAttribute"`
EmailAttribute string `json:"emailAttribute"`
SearchBeforeAuth bool `json:"searchBeforeAuth"`
SearchFilter string `json:"searchFilter"`
SearchScope string `json:"searchScope"`
SearchBindDN string `json:"searchBindDN"`
SearchBindPw string `json:"searchBindPw"`
BindTemplate string `json:"bindTemplate"`
TrustedEmailProvider bool `json:"trustedEmailProvider"`
}
func (cfg *LDAPConnectorConfig) ConnectorID() string {
return cfg.ID
}
func (cfg *LDAPConnectorConfig) ConnectorType() string {
return LDAPConnectorType
}
type LDAPConnector struct {
id string
idp *LDAPIdentityProvider
namespace url.URL
trustedEmailProvider bool
loginFunc oidc.LoginFunc
loginTpl *template.Template
}
func (cfg *LDAPConnectorConfig) Connector(ns url.URL, lf oidc.LoginFunc, tpls *template.Template) (Connector, error) {
ns.Path = path.Join(ns.Path, httpPathCallback)
tpl := tpls.Lookup(LDAPLoginPageTemplateName)
if tpl == nil {
return nil, fmt.Errorf("unable to find necessary HTML template")
}
if cfg.UseTLS && cfg.UseSSL {
return nil, fmt.Errorf("Invalid configuration. useTLS and useSSL are mutual exclusive.")
}
if len(cfg.CertFile) > 0 && len(cfg.KeyFile) == 0 {
return nil, fmt.Errorf("Invalid configuration. Both certFile and keyFile must be specified.")
}
var nameAttribute, emailAttribute, bindTemplate string
if len(cfg.NameAttribute) > 0 {
nameAttribute = cfg.NameAttribute
} else {
nameAttribute = "cn"
}
if len(cfg.EmailAttribute) > 0 {
emailAttribute = cfg.EmailAttribute
} else {
emailAttribute = "mail"
}
if len(cfg.BindTemplate) > 0 {
if cfg.SearchBeforeAuth {
log.Warningf("bindTemplate not used when searchBeforeAuth specified.")
}
bindTemplate = cfg.BindTemplate
} else {
bindTemplate = "uid=%u,%b"
}
var searchScope int
if len(cfg.SearchScope) > 0 {
switch {
case strings.EqualFold(cfg.SearchScope, "BASE"):
searchScope = ldap.ScopeBaseObject
case strings.EqualFold(cfg.SearchScope, "ONE"):
searchScope = ldap.ScopeSingleLevel
case strings.EqualFold(cfg.SearchScope, "SUB"):
searchScope = ldap.ScopeWholeSubtree
default:
return nil, fmt.Errorf("Invalid value for searchScope: '%v'. Must be one of 'base', 'one' or 'sub'.", cfg.SearchScope)
}
} else {
searchScope = ldap.ScopeSingleLevel
}
if cfg.Timeout != 0 {
ldap.DefaultTimeout = cfg.Timeout * time.Millisecond
}
tlsConfig := &tls.Config{
ServerName: cfg.ServerHost,
InsecureSkipVerify: cfg.SkipCertVerification,
}
if (cfg.UseTLS || cfg.UseSSL) && len(cfg.CaFile) > 0 {
buf, err := ioutil.ReadFile(cfg.CaFile)
if err != nil {
return nil, err
}
rootCertPool := x509.NewCertPool()
ok := rootCertPool.AppendCertsFromPEM(buf)
if ok {
tlsConfig.RootCAs = rootCertPool
} else {
return nil, fmt.Errorf("%v: Unable to parse certificate data.", cfg.CaFile)
}
}
if (cfg.UseTLS || cfg.UseSSL) && len(cfg.CertFile) > 0 && len(cfg.KeyFile) > 0 {
cert, err := tls.LoadX509KeyPair(cfg.CertFile, cfg.KeyFile)
if err != nil {
return nil, err
}
tlsConfig.Certificates = []tls.Certificate{cert}
}
idp := &LDAPIdentityProvider{
serverHost: cfg.ServerHost,
serverPort: cfg.ServerPort,
useTLS: cfg.UseTLS,
useSSL: cfg.UseSSL,
baseDN: cfg.BaseDN,
nameAttribute: nameAttribute,
emailAttribute: emailAttribute,
searchBeforeAuth: cfg.SearchBeforeAuth,
searchFilter: cfg.SearchFilter,
searchScope: searchScope,
searchBindDN: cfg.SearchBindDN,
searchBindPw: cfg.SearchBindPw,
bindTemplate: bindTemplate,
tlsConfig: tlsConfig,
}
idpc := &LDAPConnector{
id: cfg.ID,
idp: idp,
namespace: ns,
trustedEmailProvider: cfg.TrustedEmailProvider,
loginFunc: lf,
loginTpl: tpl,
}
return idpc, nil
}
func (c *LDAPConnector) ID() string {
return c.id
}
func (c *LDAPConnector) Healthy() error {
ldapConn, err := c.idp.LDAPConnect()
if err == nil {
ldapConn.Close()
}
return err
}
func (c *LDAPConnector) LoginURL(sessionKey, prompt string) (string, error) {
q := url.Values{}
q.Set("session_key", sessionKey)
q.Set("prompt", prompt)
enc := q.Encode()
return path.Join(c.namespace.Path, "login") + "?" + enc, nil
}
func (c *LDAPConnector) Register(mux *http.ServeMux, errorURL url.URL) {
route := path.Join(c.namespace.Path, "login")
mux.Handle(route, handleLoginFunc(c.loginFunc, c.loginTpl, c.idp, route, errorURL))
}
func (c *LDAPConnector) Sync() chan struct{} {
return make(chan struct{})
}
func (c *LDAPConnector) TrustedEmailProvider() bool {
return c.trustedEmailProvider
}
type LDAPIdentityProvider struct {
serverHost string
serverPort uint16
useTLS bool
useSSL bool
baseDN string
nameAttribute string
emailAttribute string
searchBeforeAuth bool
searchFilter string
searchScope int
searchBindDN string
searchBindPw string
bindTemplate string
tlsConfig *tls.Config
}
func (m *LDAPIdentityProvider) LDAPConnect() (*ldap.Conn, error) {
var err error
var ldapConn *ldap.Conn
log.Debugf("LDAPConnect()")
if m.useSSL {
ldapConn, err = ldap.DialTLS("tcp", fmt.Sprintf("%s:%d", m.serverHost, m.serverPort), m.tlsConfig)
if err != nil {
return nil, err
}
} else {
ldapConn, err = ldap.Dial("tcp", fmt.Sprintf("%s:%d", m.serverHost, m.serverPort))
if err != nil {
return nil, err
}
if m.useTLS {
err = ldapConn.StartTLS(m.tlsConfig)
if err != nil {
return nil, err
}
}
}
return ldapConn, err
}
func (m *LDAPIdentityProvider) ParseString(template, username string) string {
result := template
result = strings.Replace(result, "%u", username, -1)
result = strings.Replace(result, "%b", m.baseDN, -1)
return result
}
func (m *LDAPIdentityProvider) Identity(username, password string) (*oidc.Identity, error) {
var err error
var bindDN, ldapUid, ldapName, ldapEmail string
var ldapConn *ldap.Conn
ldapConn, err = m.LDAPConnect()
if err != nil {
return nil, err
}
defer ldapConn.Close()
if m.searchBeforeAuth {
err = ldapConn.Bind(m.searchBindDN, m.searchBindPw)
if err != nil {
return nil, err
}
filter := m.ParseString(m.searchFilter, username)
attributes := []string{
"entryDN",
m.nameAttribute,
m.emailAttribute,
}
s := ldap.NewSearchRequest(m.baseDN, m.searchScope, ldap.NeverDerefAliases, 0, 0, false, filter, attributes, nil)
sr, err := ldapConn.Search(s)
if err != nil {
return nil, err
}
if len(sr.Entries) == 0 {
err = fmt.Errorf("Search returned no match. filter='%v' base='%v'", filter, m.baseDN)
return nil, err
}
bindDN = sr.Entries[0].GetAttributeValue("entryDN")
ldapName = sr.Entries[0].GetAttributeValue(m.nameAttribute)
ldapEmail = sr.Entries[0].GetAttributeValue(m.emailAttribute)
// drop to anonymous bind, prepare for bind as user
err = ldapConn.Bind("", "")
if err != nil {
// unsupported or disallowed, reconnect
log.Warningf("Re-connecting to LDAP Server after failure to bind anonymously: %v", err)
ldapConn.Close()
ldapConn, err = m.LDAPConnect()
if err != nil {
return nil, err
}
}
} else {
bindDN = m.ParseString(m.bindTemplate, username)
}
// authenticate user
err = ldapConn.Bind(bindDN, password)
if err != nil {
return nil, err
}
ldapUid = bindDN
return &oidc.Identity{
ID: ldapUid,
Name: ldapName,
Email: ldapEmail,
}, nil
}