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authentik/outpost/pkg/ldap/instance_bind.go

187 lines
5.9 KiB
Go

package ldap
import (
"context"
"errors"
"fmt"
"net"
"net/http"
"net/http/cookiejar"
"net/url"
"strings"
"time"
goldap "github.com/go-ldap/ldap/v3"
"github.com/nmcclain/ldap"
"goauthentik.io/outpost/api"
"goauthentik.io/outpost/pkg"
"goauthentik.io/outpost/pkg/ak"
)
const ContextUserKey = "ak_user"
func (pi *ProviderInstance) getUsername(dn string) (string, error) {
if !strings.HasSuffix(strings.ToLower(dn), strings.ToLower(pi.BaseDN)) {
return "", errors.New("invalid base DN")
}
dns, err := goldap.ParseDN(dn)
if err != nil {
return "", err
}
for _, part := range dns.RDNs {
for _, attribute := range part.Attributes {
if strings.ToLower(attribute.Type) == "cn" {
return attribute.Value, nil
}
}
}
return "", errors.New("failed to find cn")
}
func (pi *ProviderInstance) Bind(username string, bindDN, bindPW string, conn net.Conn) (ldap.LDAPResultCode, error) {
jar, err := cookiejar.New(nil)
if err != nil {
pi.log.WithError(err).Warning("Failed to create cookiejar")
return ldap.LDAPResultOperationsError, nil
}
host, _, err := net.SplitHostPort(conn.RemoteAddr().String())
if err != nil {
pi.log.WithError(err).Warning("Failed to get remote IP")
return ldap.LDAPResultOperationsError, nil
}
// Create new http client that also sets the correct ip
config := api.NewConfiguration()
// Carry over the bearer authentication, so that failed login attempts are attributed to the outpost
config.DefaultHeader = pi.s.ac.Client.GetConfig().DefaultHeader
config.Host = pi.s.ac.Client.GetConfig().Host
config.Scheme = pi.s.ac.Client.GetConfig().Scheme
config.HTTPClient = &http.Client{
Jar: jar,
Transport: newTransport(ak.SetUserAgent(ak.GetTLSTransport(), pkg.UserAgent()), map[string]string{
"X-authentik-remote-ip": host,
}),
}
// create the API client, with the transport
apiClient := api.NewAPIClient(config)
params := url.Values{}
params.Add("goauthentik.io/outpost/ldap", "true")
passed, err := pi.solveFlowChallenge(username, bindPW, apiClient, params.Encode(), 1)
if err != nil {
pi.log.WithField("bindDN", bindDN).WithError(err).Warning("failed to solve challenge")
return ldap.LDAPResultOperationsError, nil
}
if !passed {
return ldap.LDAPResultInvalidCredentials, nil
}
r, err := pi.s.ac.Client.CoreApi.CoreApplicationsCheckAccessRetrieve(context.Background(), pi.appSlug).Execute()
if r.StatusCode == 403 {
pi.log.WithField("bindDN", bindDN).Info("Access denied for user")
return ldap.LDAPResultInsufficientAccessRights, nil
}
if err != nil {
pi.log.WithField("bindDN", bindDN).WithError(err).Warning("failed to check access")
return ldap.LDAPResultOperationsError, nil
}
pi.log.WithField("bindDN", bindDN).Info("User has access")
// Get user info to store in context
userInfo, _, err := pi.s.ac.Client.CoreApi.CoreUsersMeRetrieve(context.Background()).Execute()
if err != nil {
pi.log.WithField("bindDN", bindDN).WithError(err).Warning("failed to get user info")
return ldap.LDAPResultOperationsError, nil
}
pi.boundUsersMutex.Lock()
pi.boundUsers[bindDN] = UserFlags{
UserInfo: userInfo.User,
CanSearch: pi.SearchAccessCheck(userInfo.User),
}
defer pi.boundUsersMutex.Unlock()
pi.delayDeleteUserInfo(username)
return ldap.LDAPResultSuccess, nil
}
// SearchAccessCheck Check if the current user is allowed to search
func (pi *ProviderInstance) SearchAccessCheck(user api.User) bool {
for _, group := range user.Groups {
for _, allowedGroup := range pi.searchAllowedGroups {
pi.log.WithField("userGroup", group.Pk).WithField("allowedGroup", allowedGroup).Trace("Checking search access")
if group.Pk == allowedGroup.String() {
pi.log.WithField("group", group.Name).Info("Allowed access to search")
return true
}
}
}
return false
}
func (pi *ProviderInstance) delayDeleteUserInfo(dn string) {
ticker := time.NewTicker(30 * time.Second)
quit := make(chan struct{})
go func() {
for {
select {
case <-ticker.C:
pi.boundUsersMutex.Lock()
delete(pi.boundUsers, dn)
pi.boundUsersMutex.Unlock()
close(quit)
case <-quit:
ticker.Stop()
return
}
}
}()
}
func (pi *ProviderInstance) solveFlowChallenge(bindDN string, password string, client *api.APIClient, urlParams string, depth int) (bool, error) {
req := client.FlowsApi.FlowsExecutorGet(context.Background(), pi.flowSlug)
req.Query(urlParams)
challenge, _, err := req.Execute()
if err != nil {
pi.log.WithError(err).Warning("Failed to get challenge")
return false, err
}
pi.log.WithField("component", challenge.Component).WithField("type", challenge.Type).Debug("Got challenge")
responseReq := client.FlowsApi.FlowsExecutorSolve(context.Background(), pi.flowSlug)
responseReq.Query(urlParams)
switch *challenge.Component {
case "ak-stage-identification":
responseReq.RequestBody(map[string]interface{}{
"uid_field": bindDN,
})
case "ak-stage-password":
responseReq.RequestBody(map[string]interface{}{
"password": password,
})
case "ak-stage-access-denied":
return false, errors.New("got ak-stage-access-denied")
default:
return false, fmt.Errorf("unsupported challenge type: %s", *challenge.Component)
}
response, _, err := responseReq.Execute()
pi.log.WithField("component", response.Component).WithField("type", response.Type).Debug("Got response")
switch *response.Component {
case "ak-stage-access-denied":
return false, errors.New("got ak-stage-access-denied")
}
if response.Type == "redirect" {
return true, nil
}
if err != nil {
pi.log.WithError(err).Warning("Failed to submit challenge")
return false, err
}
if len(*response.ResponseErrors) > 0 {
for key, errs := range *response.ResponseErrors {
for _, err := range errs {
pi.log.WithField("key", key).WithField("code", err.Code).Debug(err.String)
return false, nil
}
}
}
if depth >= 10 {
return false, errors.New("exceeded stage recursion depth")
}
return pi.solveFlowChallenge(bindDN, password, client, urlParams, depth+1)
}