Files
opencloud/glauth/pkg/server/glauth/handler.go
Jörn Friedrich Dreyer 033feb46a7 glauth: Reenable configuring backends
Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>
2020-09-24 12:09:43 +02:00

463 lines
15 KiB
Go

package glauth
import (
"context"
"errors"
"fmt"
"net"
"strconv"
"strings"
"github.com/glauth/glauth/pkg/config"
"github.com/glauth/glauth/pkg/handler"
"github.com/glauth/glauth/pkg/stats"
ber "github.com/nmcclain/asn1-ber"
"github.com/nmcclain/ldap"
accounts "github.com/owncloud/ocis/accounts/pkg/proto/v0"
"github.com/owncloud/ocis/ocis-pkg/log"
)
type queryType string
const (
usersQuery queryType = "users"
groupsQuery queryType = "groups"
)
type ocisHandler struct {
as accounts.AccountsService
gs accounts.GroupsService
log log.Logger
cfg *config.Config
}
func (h ocisHandler) Bind(bindDN, bindSimplePw string, conn net.Conn) (ldap.LDAPResultCode, error) {
bindDN = strings.ToLower(bindDN)
baseDN := strings.ToLower("," + h.cfg.Backend.BaseDN)
h.log.Debug().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Interface("src", conn.RemoteAddr()).
Msg("Bind request")
stats.Frontend.Add("bind_reqs", 1)
// parse the bindDN - ensure that the bindDN ends with the BaseDN
if !strings.HasSuffix(bindDN, baseDN) {
h.log.Error().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Interface("src", conn.RemoteAddr()).
Msg("BindDN not part of our BaseDN")
return ldap.LDAPResultInvalidCredentials, nil
}
parts := strings.Split(strings.TrimSuffix(bindDN, baseDN), ",")
if len(parts) > 2 {
h.log.Error().
Str("binddn", bindDN).
Int("numparts", len(parts)).
Interface("src", conn.RemoteAddr()).
Msg("BindDN should have only one or two parts")
return ldap.LDAPResultInvalidCredentials, nil
}
userName := strings.TrimPrefix(parts[0], "cn=")
// check password
res, err := h.as.ListAccounts(context.TODO(), &accounts.ListAccountsRequest{
//Query: fmt.Sprintf("username eq '%s'", username),
// TODO this allows lookung up users when you know the username using basic auth
// adding the password to the query is an option but sending the sover the wira a la scim seems ugly
// but to set passwords our accounts need it anyway
Query: fmt.Sprintf("login eq '%s' and password eq '%s'", userName, bindSimplePw),
})
if err != nil || len(res.Accounts) == 0 {
h.log.Error().
Str("username", userName).
Str("binddn", bindDN).
Interface("src", conn.RemoteAddr()).
Msg("Login failed")
return ldap.LDAPResultInvalidCredentials, nil
}
stats.Frontend.Add("bind_successes", 1)
h.log.Debug().
Str("binddn", bindDN).
Interface("src", conn.RemoteAddr()).
Msg("Bind success")
return ldap.LDAPResultSuccess, nil
}
func (h ocisHandler) Search(bindDN string, searchReq ldap.SearchRequest, conn net.Conn) (ldap.ServerSearchResult, error) {
bindDN = strings.ToLower(bindDN)
baseDN := strings.ToLower("," + h.cfg.Backend.BaseDN)
searchBaseDN := strings.ToLower(searchReq.BaseDN)
h.log.Debug().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Interface("src", conn.RemoteAddr()).
Msg("Search request")
stats.Frontend.Add("search_reqs", 1)
// validate the user is authenticated and has appropriate access
if len(bindDN) < 1 {
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultInsufficientAccessRights,
}, fmt.Errorf("search error: Anonymous BindDN not allowed %s", bindDN)
}
if !strings.HasSuffix(bindDN, baseDN) {
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultInsufficientAccessRights,
}, fmt.Errorf("search error: BindDN %s not in our BaseDN %s", bindDN, h.cfg.Backend.BaseDN)
}
if !strings.HasSuffix(searchBaseDN, h.cfg.Backend.BaseDN) {
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultInsufficientAccessRights,
}, fmt.Errorf("search error: search BaseDN %s is not in our BaseDN %s", searchBaseDN, h.cfg.Backend.BaseDN)
}
var qtype queryType = ""
query := ""
var code ldap.LDAPResultCode
var err error
if searchReq.Filter == "(&)" { // see Absolute True and False Filters in https://tools.ietf.org/html/rfc4526#section-2
query = ""
} else {
var cf *ber.Packet
cf, err = ldap.CompileFilter(searchReq.Filter)
if err != nil {
h.log.Debug().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Interface("src", conn.RemoteAddr()).
Msg("could not compile filter")
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultOperationsError,
}, fmt.Errorf("Search Error: error parsing filter: %s", searchReq.Filter)
}
qtype, query, code, err = parseFilter(cf)
if err != nil {
return ldap.ServerSearchResult{
ResultCode: code,
}, fmt.Errorf("Search Error: error parsing filter: %s", searchReq.Filter)
}
// check if the searchBaseDN already has a username and add it to the query
parts := strings.Split(strings.TrimSuffix(searchBaseDN, baseDN), ",")
if len(parts) > 0 && strings.HasPrefix(parts[0], "cn=") {
if len(query) > 0 {
query += " AND "
}
query += fmt.Sprintf("on_premises_sam_account_name eq '%s'", escapeValue(strings.TrimPrefix(parts[0], "cn=")))
}
}
entries := []*ldap.Entry{}
h.log.Debug().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Str("qtype", string(qtype)).
Str("query", query).
Msg("parsed query")
switch qtype {
case usersQuery:
accounts, err := h.as.ListAccounts(context.TODO(), &accounts.ListAccountsRequest{
Query: query,
})
if err != nil {
h.log.Error().
Err(err).
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Str("query", query).
Interface("src", conn.RemoteAddr()).
Msg("Could not list accounts")
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultOperationsError,
}, errors.New("search error: error listing users")
}
entries = append(entries, h.mapAccounts(accounts.Accounts)...)
case groupsQuery:
groups, err := h.gs.ListGroups(context.TODO(), &accounts.ListGroupsRequest{
Query: query,
})
if err != nil {
h.log.Error().
Err(err).
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Str("query", query).
Interface("src", conn.RemoteAddr()).
Msg("Could not list groups")
return ldap.ServerSearchResult{
ResultCode: ldap.LDAPResultOperationsError,
}, errors.New("search error: error listing groups")
}
entries = append(entries, h.mapGroups(groups.Groups)...)
}
stats.Frontend.Add("search_successes", 1)
h.log.Debug().
Str("binddn", bindDN).
Str("basedn", h.cfg.Backend.BaseDN).
Str("filter", searchReq.Filter).
Interface("src", conn.RemoteAddr()).
Msg("AP: Search OK")
return ldap.ServerSearchResult{
Entries: entries,
Referrals: []string{},
Controls: []ldap.Control{},
ResultCode: ldap.LDAPResultSuccess,
}, nil
}
func attribute(name string, values ...string) *ldap.EntryAttribute {
return &ldap.EntryAttribute{
Name: name,
Values: values,
}
}
func (h ocisHandler) mapAccounts(accounts []*accounts.Account) []*ldap.Entry {
var entries []*ldap.Entry
for i := range accounts {
attrs := []*ldap.EntryAttribute{
attribute("objectClass", "posixAccount", "inetOrgPerson", "organizationalPerson", "Person", "top"),
attribute("cn", accounts[i].PreferredName),
attribute("uid", accounts[i].PreferredName),
attribute("sn", accounts[i].PreferredName),
attribute("homeDirectory", ""),
attribute("ownCloudUUID", accounts[i].Id), // see https://github.com/butonic/owncloud-ldap-schema/blob/master/owncloud.schema#L28-L34
}
if accounts[i].DisplayName != "" {
attrs = append(attrs, attribute("displayName", accounts[i].DisplayName))
}
if accounts[i].Mail != "" {
attrs = append(attrs, attribute("mail", accounts[i].Mail))
}
if accounts[i].UidNumber != 0 { // TODO no root?
attrs = append(attrs, attribute("uidnumber", strconv.FormatInt(accounts[i].UidNumber, 10)))
}
if accounts[i].GidNumber != 0 {
attrs = append(attrs, attribute("gidnumber", strconv.FormatInt(accounts[i].GidNumber, 10)))
}
if accounts[i].Description != "" {
attrs = append(attrs, attribute("description", accounts[i].Description))
}
dn := fmt.Sprintf("%s=%s,%s=%s,%s",
h.cfg.Backend.NameFormat,
accounts[i].PreferredName,
h.cfg.Backend.GroupFormat,
"users",
h.cfg.Backend.BaseDN,
)
entries = append(entries, &ldap.Entry{DN: dn, Attributes: attrs})
}
return entries
}
func (h ocisHandler) mapGroups(groups []*accounts.Group) []*ldap.Entry {
var entries []*ldap.Entry
for i := range groups {
attrs := []*ldap.EntryAttribute{
attribute("objectClass", "posixGroup", "groupOfNames", "top"),
attribute("cn", groups[i].OnPremisesSamAccountName),
attribute("ownCloudUUID", groups[i].Id), // see https://github.com/butonic/owncloud-ldap-schema/blob/master/owncloud.schema#L28-L34
}
if groups[i].DisplayName != "" {
attrs = append(attrs, attribute("displayName", groups[i].DisplayName))
}
if groups[i].GidNumber != 0 {
attrs = append(attrs, attribute("gidnumber", strconv.FormatInt(groups[i].GidNumber, 10)))
}
if groups[i].Description != "" {
attrs = append(attrs, attribute("description", groups[i].Description))
}
dn := fmt.Sprintf("%s=%s,%s=%s,%s",
h.cfg.Backend.NameFormat,
groups[i].OnPremisesSamAccountName,
h.cfg.Backend.GroupFormat,
"groups",
h.cfg.Backend.BaseDN,
)
memberUids := make([]string, len(groups[i].Members))
for j := range groups[i].Members {
memberUids[j] = groups[i].Members[j].PreferredName
}
attrs = append(attrs, attribute("memberuid", memberUids...))
entries = append(entries, &ldap.Entry{DN: dn, Attributes: attrs})
}
return entries
}
// LDAP filters might ask for groups and users at the same time, eg.
// (|
// (&(objectClass=posixaccount)(cn=einstein))
// (&(objectClass=posixgroup)(cn=users))
// )
// (&(objectClass=posixaccount)(objectClass=posixgroup))
// qtype is one of
// "" not determined
// "users"
// "groups"
func parseFilter(f *ber.Packet) (queryType, string, ldap.LDAPResultCode, error) {
var qtype queryType
var q string
var code ldap.LDAPResultCode
var err error
switch ldap.FilterMap[f.Tag] {
case "Equality Match":
if len(f.Children) != 2 {
return "", "", ldap.LDAPResultOperationsError, errors.New("equality match must have exactly two children")
}
attribute := strings.ToLower(f.Children[0].Value.(string))
value := f.Children[1].Value.(string)
// replace attributes
switch attribute {
case "objectclass":
switch strings.ToLower(value) {
case "posixaccount", "shadowaccount", "users", "person", "inetorgperson", "organizationalperson":
qtype = usersQuery
case "posixgroup", "groups":
qtype = groupsQuery
default:
qtype = ""
}
case "ownclouduuid":
q = fmt.Sprintf("id eq '%s'", escapeValue(value))
case "cn", "uid":
// on_premises_sam_account_name is indexed using the lowercase analyzer in ocis-accounts
// TODO use "tolower(on_premises_sam_account_name) eq '%s'" to be clear about the case insensitive comparison
q = fmt.Sprintf("on_premises_sam_account_name eq '%s'", escapeValue(value))
case "mail":
q = fmt.Sprintf("mail eq '%s'", escapeValue(value))
case "displayname":
q = fmt.Sprintf("display_name eq '%s'", escapeValue(value))
case "uidnumber":
if i, err := strconv.ParseUint(value, 10, 64); err != nil {
code = ldap.LDAPResultInvalidAttributeSyntax
} else {
q = fmt.Sprintf("uid_number eq %d", i)
}
case "gidnumber":
if i, err := strconv.ParseUint(value, 10, 64); err != nil {
code = ldap.LDAPResultInvalidAttributeSyntax
} else {
q = fmt.Sprintf("gid_number eq %d", i)
}
case "description":
q = fmt.Sprintf("description eq '%s'", escapeValue(value))
default:
code = ldap.LDAPResultUndefinedAttributeType
err = fmt.Errorf("unrecognized assertion type '%s' in filter item", attribute)
}
return qtype, q, code, err
case "Substrings":
if len(f.Children) != 2 {
return "", "", ldap.LDAPResultOperationsError, errors.New("substrings filter must have exactly two children")
}
attribute := strings.ToLower(f.Children[0].Value.(string))
if len(f.Children[1].Children) != 1 {
return "", "", ldap.LDAPResultUnwillingToPerform, fmt.Errorf("substrings filter only supports prefix match")
}
value := f.Children[1].Children[0].Value.(string)
// replace attributes
switch attribute {
case "objectclass":
switch strings.ToLower(value) {
case "posixaccount", "shadowaccount", "users", "person", "inetorgperson", "organizationalperson":
qtype = usersQuery
case "posixgroup", "groups":
qtype = groupsQuery
default:
qtype = ""
}
case "ownclouduuid":
q = fmt.Sprintf("startswith(id,'%s')", escapeValue(value))
case "cn", "uid":
// on_premises_sam_account_name is indexed using the lowercase analyzer in ocis-accounts
// TODO use "tolower(on_premises_sam_account_name) eq '%s'" to be clear about the case insensitive comparison
q = fmt.Sprintf("startswith(on_premises_sam_account_name,'%s')", escapeValue(value))
case "mail":
q = fmt.Sprintf("startswith(mail,'%s')", escapeValue(value))
case "displayname":
q = fmt.Sprintf("startswith(display_name,'%s')", escapeValue(value))
case "description":
q = fmt.Sprintf("startswith(description,'%s')", escapeValue(value))
default:
code = ldap.LDAPResultUndefinedAttributeType
err = fmt.Errorf("unrecognized assertion type '%s' in filter item", attribute)
}
return qtype, q, code, err
case "And", "Or":
subQueries := []string{}
for i := range f.Children {
var subQuery string
var qt queryType
qt, subQuery, code, err = parseFilter(f.Children[i])
if err != nil {
return "", "", code, err
}
if qtype == "" {
qtype = qt
} else if qt != "" && qt != qtype {
return "", "", ldap.LDAPResultUnwillingToPerform, fmt.Errorf("mixing user and group filters not supported")
}
if subQuery != "" {
subQueries = append(subQueries, subQuery)
}
}
return qtype, strings.Join(subQueries, " "+strings.ToLower(ldap.FilterMap[f.Tag])+" "), ldap.LDAPResultSuccess, nil
case "Not":
if len(f.Children) != 1 {
return "", "", ldap.LDAPResultOperationsError, errors.New("not filter match must have exactly one child")
}
qtype, subQuery, code, err := parseFilter(f.Children[0])
if err != nil {
return "", "", code, err
}
if subQuery != "" {
q = fmt.Sprintf("not %s", subQuery)
}
return qtype, q, code, nil
}
return qtype, q, ldap.LDAPResultUnwillingToPerform, fmt.Errorf("%s filter not implemented", ldap.FilterMap[f.Tag])
}
// escapeValue escapes all special characters in the value
func escapeValue(value string) string {
return strings.ReplaceAll(value, "'", "''")
}
func (h ocisHandler) Close(boundDN string, conn net.Conn) error {
stats.Frontend.Add("closes", 1)
return nil
}
// NewOCISHandler implements a glauth backend with ocis-accounts as the datasource
func NewOCISHandler(opts ...Option) handler.Handler {
options := newOptions(opts...)
handler := ocisHandler{
log: options.Logger,
cfg: options.Config,
as: options.AccountsService,
gs: options.GroupsService,
}
return handler
}