Add extra LDAP configuration validation (#14535)

- The result now contains suggestions on fixing common configuration issues.
- These suggestions will subsequently be exposed in console/mc
This commit is contained in:
Aditya Manthramurthy 2022-03-16 19:57:36 -07:00 committed by GitHub
parent 7b81967a3c
commit ce97313fda
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 805 additions and 357 deletions

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@ -110,7 +110,7 @@ export MINIO_IDENTITY_LDAP_SERVER_ADDR=myldapserver.com:636
export MINIO_IDENTITY_LDAP_LOOKUP_BIND_DN='cn=admin,dc=min,dc=io'
export MINIO_IDENTITY_LDAP_LOOKUP_BIND_PASSWORD=admin
export MINIO_IDENTITY_LDAP_USER_DN_SEARCH_BASE_DN='ou=hwengg,dc=min,dc=io'
export MINIO_IDENTITY_LDAP_USER_DN_SEARCH_FILTER='(uid=%s,cn=accounts,dc=min,dc=io)'
export MINIO_IDENTITY_LDAP_USER_DN_SEARCH_FILTER='(uid=%s)'
export MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY=on
```

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@ -0,0 +1,271 @@
// Copyright (c) 2015-2022 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package ldap
import (
"fmt"
"strings"
)
// Result - type for high-level names for the validation status of the config.
type Result string
// Constant values for Result type.
const (
ConfigOk Result = "Config OK"
ConnectivityError Result = "LDAP Server Connection Error"
LookupBindError Result = "LDAP Lookup Bind Error"
UserSearchParamsMisconfigured Result = "User Search Parameters Misconfigured"
GroupSearchParamsMisconfigured Result = "Group Search Parameters Misconfigured"
UserDNLookupError Result = "User DN Lookup Error"
GroupMembershipsLookupError Result = "Group Memberships Lookup Error"
)
// Validation returns feedback on the configuration. The `Suggestion` field
// needs to be "printed" for friendly display (it can contain escaped newlines
// `\n`).
type Validation struct {
Result Result
Detail string
Suggestion string
ErrCause error
}
// Error instance for Validation.
func (v Validation) Error() string {
if v.Result == ConfigOk {
return ""
}
return fmt.Sprintf("%s: %s", string(v.Result), v.Detail)
}
// IsOk - returns if the validation succeeded.
func (v Validation) IsOk() bool {
return v.Result == ConfigOk
}
// UserLookupResult returns the DN found for the test user and their group
// memberships.
type UserLookupResult struct {
DN string
GroupDNMemberships []string
}
// Validate validates the LDAP configuration. It can be called with any subset
// of configuration parameters provided by the user - it will return
// information on what needs to be done to fix the problem if any.
//
// This function updates the UserDNSearchBaseDistNames and
// GroupSearchBaseDistNames fields of the Config - however this an idempotent
// operation. This is done to support configuration validation in Console/mc and
// for tests.
func (l *Config) Validate() Validation {
if !l.Enabled {
return Validation{Result: ConfigOk, Detail: "Config is not enabled"}
}
if l.ServerAddr == "" {
return Validation{
Result: ConnectivityError,
Detail: "Address is empty",
Suggestion: "Set a server address.",
}
}
conn, err := l.Connect()
if err != nil {
return Validation{
Result: ConnectivityError,
Detail: fmt.Sprintf("Could not connect to LDAP server: %v", err),
ErrCause: err,
Suggestion: `Check:
(1) server address
(2) TLS parameters, and
(3) LDAP server's TLS certificate is trusted by MinIO (when using TLS - highly recommended)`,
}
}
defer conn.Close()
if l.LookupBindDN == "" {
return Validation{
Result: LookupBindError,
Detail: "Lookup Bind UserDN not specified",
Suggestion: "Specify LDAP service account credentials for performing lookups.",
}
}
if err := l.lookupBind(conn); err != nil {
return Validation{
Result: LookupBindError,
ErrCause: err,
Detail: fmt.Sprintf("Error connecting as LDAP Lookup Bind user: %v", err),
Suggestion: "Check LDAP Lookup Bind user credentials and if user is allowed to login",
}
}
// Validate User Lookup parameters
if l.UserDNSearchBaseDistName == "" {
return Validation{
Result: UserSearchParamsMisconfigured,
Detail: "UserDN search base is empty",
Suggestion: "Set the UserDN search base to the DN of the directory subtree where users are present",
}
}
l.UserDNSearchBaseDistNames = strings.Split(l.UserDNSearchBaseDistName, dnDelimiter)
if l.UserDNSearchFilter == "" {
return Validation{
Result: UserSearchParamsMisconfigured,
Detail: "UserDN search filter is empty",
Suggestion: `Set the UserDN search filter template:
Use "%s" - it will be replaced by the login user name and sent to the LDAP server.
For example: "(uid=%s)"`,
}
}
if strings.Contains(l.UserDNSearchFilter, "%d") {
return Validation{
Result: UserSearchParamsMisconfigured,
Detail: "User DN search filter contains `%d`",
Suggestion: `User DN search filter is a template where "%s" is replaced by the login username.
"%d" is not supported here.
Please provide a search filter containing "%s"`,
}
}
if !strings.Contains(l.UserDNSearchFilter, "%s") {
return Validation{
Result: UserSearchParamsMisconfigured,
Detail: "User DN search filter does not contain `%s`",
Suggestion: `During login, the user's DN is looked up using the search filter template:
"%s" gets replaced by the given username - it must be used.
Enter an LDAP search filter containing "%s"`,
}
}
// If group lookup is not configured, it's ok.
if l.GroupSearchBaseDistName != "" || l.GroupSearchFilter != "" {
// Validate Group Search parameters as they are given.
if l.GroupSearchBaseDistName == "" {
return Validation{
Result: GroupSearchParamsMisconfigured,
Detail: "Group Search Base DN is required.",
Suggestion: `Since you entered a value for the Group Search Filter - enter a value for the Group Search Base DN too:
Enter this value as the DN of the subtree where groups will be found.`,
}
}
l.GroupSearchBaseDistNames = strings.Split(l.GroupSearchBaseDistName, dnDelimiter)
if l.GroupSearchFilter == "" {
return Validation{
Result: GroupSearchParamsMisconfigured,
Detail: "Group Search Filter is required.",
Suggestion: `Since you entered a value for the Group Search Base DN - enter a value for the Group Search Filter too. This is a template where, before the query is sent to the server:
"%s" is replaced with the login username;
"%d" is replaced with the DN of the login user.
For example: "(&(objectclass=groupOfNames)(memberUid=%s))"`,
}
}
if !strings.Contains(l.GroupSearchFilter, "%d") && !strings.Contains(l.GroupSearchFilter, "%s") {
return Validation{
Result: GroupSearchParamsMisconfigured,
Detail: `GroupSearchFilter must contain at least one of "%s" or "%d"`,
Suggestion: `During group membership lookup the group search filter template is used:
"%s" gets replaced by the given username, and
"%d" gets replaced by the user's DN.
Either one is needed to find only groups that the user is a member of.
Enter an LDAP search filter template using at least one of these.`,
}
}
}
return Validation{
Result: ConfigOk,
}
}
// ValidateLookup takes a test username and performs user and group lookup (if
// configured) and returns the result. It is to validate the LDAP configuration.
// The lookup is performed without requiring the password for the test user -
// and so can be used to test any LDAP user intending to use MinIO.
func (l *Config) ValidateLookup(testUsername string) (*UserLookupResult, Validation) {
if testUsername == "" {
return nil, Validation{
Result: UserDNLookupError,
Detail: "Provided username is empty",
}
}
if r := l.Validate(); !r.IsOk() {
return nil, r
}
conn, err := l.Connect()
if err != nil {
return nil, Validation{
Result: ConnectivityError,
Detail: fmt.Sprintf("Could not connect to LDAP server: %v", err),
ErrCause: err,
Suggestion: `Check:
(1) server address
(2) TLS parameters, and
(3) LDAP server's TLS certificate is trusted by MinIO (when using TLS - highly recommended)`,
}
}
defer conn.Close()
if err := l.lookupBind(conn); err != nil {
return nil, Validation{
Result: LookupBindError,
ErrCause: err,
Detail: fmt.Sprintf("Error connecting as LDAP Lookup Bind user: %v", err),
Suggestion: "Check LDAP Lookup Bind user credentials and if user is allowed to login",
}
}
// Lookup the given username.
dn, err := l.lookupUserDN(conn, testUsername)
if err != nil {
return nil, Validation{
Result: UserDNLookupError,
Detail: fmt.Sprintf("Got an error when looking up user (%s) DN: %v", testUsername, err),
ErrCause: err,
Suggestion: `Check if this is a temporary error and try again.
Perhaps there is an error in the user search filter or user search base DN.`,
}
}
// Lookup groups.
groups, err := l.searchForUserGroups(conn, testUsername, dn)
if err != nil {
return nil, Validation{
Result: GroupMembershipsLookupError,
Detail: fmt.Sprintf("Got an error when looking up groups for user(=>%s, dn=>%s): %v", testUsername, dn, err),
ErrCause: err,
Suggestion: `Check if this is a temporary error and try again.
Perhaps there is an error in the group search filter or group search base DN.`,
}
}
return &UserLookupResult{
DN: dn,
GroupDNMemberships: groups,
}, Validation{
Result: ConfigOk,
Detail: "User lookup done.",
}
}

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@ -0,0 +1,189 @@
// Copyright (c) 2015-2022 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package ldap
import (
"fmt"
"os"
"testing"
"github.com/minio/minio-go/v7/pkg/set"
)
const (
EnvTestLDAPServer = "LDAP_TEST_SERVER"
)
func TestConfigValidator(t *testing.T) {
ldapServer := os.Getenv(EnvTestLDAPServer)
if ldapServer == "" {
t.Skip()
}
testCases := []struct {
cfg Config
expectedResult Result
}{
{
cfg: func() Config {
v := Config{Enabled: true}
return v
}(),
expectedResult: ConnectivityError,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
return v
}(),
expectedResult: ConnectivityError,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
return v
}(),
expectedResult: LookupBindError,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin1"
return v
}(),
expectedResult: LookupBindError,
},
{ // Case 4
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
return v
}(),
expectedResult: UserSearchParamsMisconfigured,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
v.UserDNSearchFilter = "(uid=x)"
v.UserDNSearchBaseDistName = "dc=min,dc=io"
return v
}(),
expectedResult: UserSearchParamsMisconfigured,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
v.UserDNSearchFilter = "(uid=%s)"
v.UserDNSearchBaseDistName = "dc=min,dc=io"
return v
}(),
expectedResult: ConfigOk,
},
{ // Case 7
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
v.UserDNSearchFilter = "(uid=%s)"
v.UserDNSearchBaseDistName = "dc=min,dc=io"
v.GroupSearchBaseDistName = "ou=swengg,dc=min,dc=io"
v.GroupSearchFilter = "(&(objectclass=groupofnames)(member=x))"
return v
}(),
expectedResult: GroupSearchParamsMisconfigured,
},
{
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
v.UserDNSearchFilter = "(uid=%s)"
v.UserDNSearchBaseDistName = "dc=min,dc=io"
v.GroupSearchFilter = "(&(objectclass=groupofnames)(member=x))"
return v
}(),
expectedResult: GroupSearchParamsMisconfigured,
},
{ // Case 9
cfg: func() Config {
v := Config{Enabled: true}
v.ServerAddr = ldapServer
v.serverInsecure = true
v.LookupBindDN = "cn=admin,dc=min,dc=io"
v.LookupBindPassword = "admin"
v.UserDNSearchFilter = "(uid=%s)"
v.UserDNSearchBaseDistName = "dc=min,dc=io"
v.GroupSearchBaseDistName = "ou=swengg,dc=min,dc=io"
v.GroupSearchFilter = "(&(objectclass=groupofnames)(member=%d))"
return v
}(),
expectedResult: ConfigOk,
},
}
expectedDN := "uid=dillon,ou=people,ou=swengg,dc=min,dc=io"
expectedGroups := set.CreateStringSet(
"cn=projecta,ou=groups,ou=swengg,dc=min,dc=io",
"cn=projectb,ou=groups,ou=swengg,dc=min,dc=io",
)
for i, test := range testCases {
result := test.cfg.Validate()
if result.Result != test.expectedResult {
fmt.Printf("Result: %#v\n", result)
t.Fatalf("Case %d: Got `%s` expected `%s`", i, result.Result, string(test.expectedResult))
}
if result.IsOk() {
lookupResult, validationResult := test.cfg.ValidateLookup("dillon")
if !validationResult.IsOk() {
t.Fatalf("Case %d: Got unexpected validation failure: %#v\n", i, validationResult)
}
if lookupResult.DN != expectedDN {
t.Fatalf("Case %d: Got unexpected DN: %v", i, lookupResult.DN)
}
if test.cfg.GroupSearchFilter == "" {
continue
}
if !set.CreateStringSet(lookupResult.GroupDNMemberships...).Equals(expectedGroups) {
t.Fatalf("Case %d: Got unexpected groups: %v", i, lookupResult.GroupDNMemberships)
}
}
}
}

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@ -18,18 +18,9 @@
package ldap
import (
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"net"
"strconv"
"strings"
"time"
ldap "github.com/go-ldap/ldap/v3"
"github.com/minio/minio-go/v7/pkg/set"
"github.com/minio/minio/internal/auth"
"github.com/minio/minio/internal/config"
"github.com/minio/pkg/env"
)
@ -52,12 +43,12 @@ type Config struct {
// User DN search parameters
UserDNSearchBaseDistName string `json:"userDNSearchBaseDN"`
UserDNSearchBaseDistNames []string `json:"-"`
UserDNSearchBaseDistNames []string `json:"-"` // Generated field
UserDNSearchFilter string `json:"userDNSearchFilter"`
// Group search parameters
GroupSearchBaseDistName string `json:"groupSearchBaseDN"`
GroupSearchBaseDistNames []string `json:"-"`
GroupSearchBaseDistNames []string `json:"-"` // Generated field
GroupSearchFilter string `json:"groupSearchFilter"`
// Lookup bind LDAP service account
@ -151,318 +142,6 @@ var (
}
)
func getGroups(conn *ldap.Conn, sreq *ldap.SearchRequest) ([]string, error) {
var groups []string
sres, err := conn.Search(sreq)
if err != nil {
// Check if there is no matching result and return empty slice.
// Ref: https://ldap.com/ldap-result-code-reference/
if ldap.IsErrorWithCode(err, 32) {
return nil, nil
}
return nil, err
}
for _, entry := range sres.Entries {
// We only queried one attribute,
// so we only look up the first one.
groups = append(groups, entry.DN)
}
return groups, nil
}
func (l *Config) lookupBind(conn *ldap.Conn) error {
var err error
if l.LookupBindPassword == "" {
err = conn.UnauthenticatedBind(l.LookupBindDN)
} else {
err = conn.Bind(l.LookupBindDN, l.LookupBindPassword)
}
if ldap.IsErrorWithCode(err, 49) {
return fmt.Errorf("LDAP Lookup Bind user invalid credentials error: %w", err)
}
return err
}
// lookupUserDN searches for the DN of the user given their username. conn is
// assumed to be using the lookup bind service account. It is required that the
// search result in at most one result.
func (l *Config) lookupUserDN(conn *ldap.Conn, username string) (string, error) {
filter := strings.ReplaceAll(l.UserDNSearchFilter, "%s", ldap.EscapeFilter(username))
var foundDistNames []string
for _, userSearchBase := range l.UserDNSearchBaseDistNames {
searchRequest := ldap.NewSearchRequest(
userSearchBase,
ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
filter,
[]string{}, // only need DN, so no pass no attributes here
nil,
)
searchResult, err := conn.Search(searchRequest)
if err != nil {
return "", err
}
for _, entry := range searchResult.Entries {
foundDistNames = append(foundDistNames, entry.DN)
}
}
if len(foundDistNames) == 0 {
return "", fmt.Errorf("User DN for %s not found", username)
}
if len(foundDistNames) != 1 {
return "", fmt.Errorf("Multiple DNs for %s found - please fix the search filter", username)
}
return foundDistNames[0], nil
}
func (l *Config) searchForUserGroups(conn *ldap.Conn, username, bindDN string) ([]string, error) {
// User groups lookup.
var groups []string
if l.GroupSearchFilter != "" {
for _, groupSearchBase := range l.GroupSearchBaseDistNames {
filter := strings.ReplaceAll(l.GroupSearchFilter, "%s", ldap.EscapeFilter(username))
filter = strings.ReplaceAll(filter, "%d", ldap.EscapeFilter(bindDN))
searchRequest := ldap.NewSearchRequest(
groupSearchBase,
ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
filter,
nil,
nil,
)
var newGroups []string
newGroups, err := getGroups(conn, searchRequest)
if err != nil {
errRet := fmt.Errorf("Error finding groups of %s: %w", bindDN, err)
return nil, errRet
}
groups = append(groups, newGroups...)
}
}
return groups, nil
}
// LookupUserDN searches for the full DN and groups of a given username
func (l *Config) LookupUserDN(username string) (string, []string, error) {
conn, err := l.Connect()
if err != nil {
return "", nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// Lookup user DN
bindDN, err := l.lookupUserDN(conn, username)
if err != nil {
errRet := fmt.Errorf("Unable to find user DN: %w", err)
return "", nil, errRet
}
groups, err := l.searchForUserGroups(conn, username, bindDN)
if err != nil {
return "", nil, err
}
return bindDN, groups, nil
}
// Bind - binds to ldap, searches LDAP and returns the distinguished name of the
// user and the list of groups.
func (l *Config) Bind(username, password string) (string, []string, error) {
conn, err := l.Connect()
if err != nil {
return "", nil, err
}
defer conn.Close()
var bindDN string
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// Lookup user DN
bindDN, err = l.lookupUserDN(conn, username)
if err != nil {
errRet := fmt.Errorf("Unable to find user DN: %w", err)
return "", nil, errRet
}
// Authenticate the user credentials.
err = conn.Bind(bindDN, password)
if err != nil {
errRet := fmt.Errorf("LDAP auth failed for DN %s: %w", bindDN, err)
return "", nil, errRet
}
// Bind to the lookup user account again to perform group search.
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// User groups lookup.
groups, err := l.searchForUserGroups(conn, username, bindDN)
if err != nil {
return "", nil, err
}
return bindDN, groups, nil
}
// Connect connect to ldap server.
func (l *Config) Connect() (ldapConn *ldap.Conn, err error) {
if l == nil {
return nil, errors.New("LDAP is not configured")
}
_, _, err = net.SplitHostPort(l.ServerAddr)
if err != nil {
// User default LDAP port if none specified "636"
l.ServerAddr = net.JoinHostPort(l.ServerAddr, "636")
}
if l.serverInsecure {
return ldap.Dial("tcp", l.ServerAddr)
}
tlsConfig := &tls.Config{
InsecureSkipVerify: l.tlsSkipVerify,
RootCAs: l.rootCAs,
}
if l.serverStartTLS {
conn, err := ldap.Dial("tcp", l.ServerAddr)
if err != nil {
return nil, err
}
err = conn.StartTLS(tlsConfig)
return conn, err
}
return ldap.DialTLS("tcp", l.ServerAddr, tlsConfig)
}
// GetExpiryDuration - return parsed expiry duration.
func (l Config) GetExpiryDuration(dsecs string) (time.Duration, error) {
if dsecs == "" {
return l.stsExpiryDuration, nil
}
d, err := strconv.Atoi(dsecs)
if err != nil {
return 0, auth.ErrInvalidDuration
}
dur := time.Duration(d) * time.Second
if dur < minLDAPExpiry || dur > maxLDAPExpiry {
return 0, auth.ErrInvalidDuration
}
return dur, nil
}
func (l Config) testConnection() error {
conn, err := l.Connect()
if err != nil {
return fmt.Errorf("Error creating connection to LDAP server: %w", err)
}
defer conn.Close()
if err = l.lookupBind(conn); err != nil {
return fmt.Errorf("Error connecting as LDAP Lookup Bind user: %w", err)
}
return nil
}
// IsLDAPUserDN determines if the given string could be a user DN from LDAP.
func (l Config) IsLDAPUserDN(user string) bool {
for _, baseDN := range l.UserDNSearchBaseDistNames {
if strings.HasSuffix(user, ","+baseDN) {
return true
}
}
return false
}
// GetNonEligibleUserDistNames - find user accounts (DNs) that are no longer
// present in the LDAP server or do not meet filter criteria anymore
func (l *Config) GetNonEligibleUserDistNames(userDistNames []string) ([]string, error) {
conn, err := l.Connect()
if err != nil {
return nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return nil, err
}
// Evaluate the filter again with generic wildcard instead of specific values
filter := strings.ReplaceAll(l.UserDNSearchFilter, "%s", "*")
nonExistentUsers := []string{}
for _, dn := range userDistNames {
searchRequest := ldap.NewSearchRequest(
dn,
ldap.ScopeBaseObject, ldap.NeverDerefAliases, 0, 0, false,
filter,
[]string{}, // only need DN, so pass no attributes here
nil,
)
searchResult, err := conn.Search(searchRequest)
if err != nil {
// Object does not exist error?
if ldap.IsErrorWithCode(err, 32) {
nonExistentUsers = append(nonExistentUsers, dn)
continue
}
return nil, err
}
if len(searchResult.Entries) == 0 {
// DN was not found - this means this user account is
// expired.
nonExistentUsers = append(nonExistentUsers, dn)
}
}
return nonExistentUsers, nil
}
// LookupGroupMemberships - for each DN finds the set of LDAP groups they are a
// member of.
func (l *Config) LookupGroupMemberships(userDistNames []string, userDNToUsernameMap map[string]string) (map[string]set.StringSet, error) {
conn, err := l.Connect()
if err != nil {
return nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return nil, err
}
res := make(map[string]set.StringSet, len(userDistNames))
for _, userDistName := range userDistNames {
username := userDNToUsernameMap[userDistName]
groups, err := l.searchForUserGroups(conn, username, userDistName)
if err != nil {
return nil, err
}
res[userDistName] = set.CreateStringSet(groups...)
}
return res, nil
}
// Enabled returns if LDAP config is enabled.
func Enabled(kvs config.KVS) bool {
return kvs.Get(ServerAddr) != ""
@ -480,6 +159,7 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
if err = config.CheckValidKeys(config.IdentityLDAPSubSys, kvs, DefaultKVS); err != nil {
return l, err
}
ldapServer := env.Get(EnvServerAddr, kvs.Get(ServerAddr))
if ldapServer == "" {
return l, nil
@ -510,44 +190,21 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
}
// Lookup bind user configuration
lookupBindDN := env.Get(EnvLookupBindDN, kvs.Get(LookupBindDN))
if lookupBindDN == "" {
return l, errors.New("Lookup Bind DN is required")
}
lookupBindPassword := env.Get(EnvLookupBindPassword, kvs.Get(LookupBindPassword))
if lookupBindDN != "" {
l.LookupBindDN = lookupBindDN
l.LookupBindPassword = lookupBindPassword
}
// Test connection to LDAP server.
if err := l.testConnection(); err != nil {
return l, fmt.Errorf("Connection test for LDAP server failed: %w", err)
}
l.LookupBindDN = env.Get(EnvLookupBindDN, kvs.Get(LookupBindDN))
l.LookupBindPassword = env.Get(EnvLookupBindPassword, kvs.Get(LookupBindPassword))
// User DN search configuration
userDNSearchBaseDN := env.Get(EnvUserDNSearchBaseDN, kvs.Get(UserDNSearchBaseDN))
userDNSearchFilter := env.Get(EnvUserDNSearchFilter, kvs.Get(UserDNSearchFilter))
if userDNSearchFilter == "" || userDNSearchBaseDN == "" {
return l, errors.New("UserDN search base DN and UserDN search filter are both required")
}
l.UserDNSearchBaseDistName = userDNSearchBaseDN
l.UserDNSearchBaseDistNames = strings.Split(userDNSearchBaseDN, dnDelimiter)
l.UserDNSearchFilter = userDNSearchFilter
l.UserDNSearchFilter = env.Get(EnvUserDNSearchFilter, kvs.Get(UserDNSearchFilter))
l.UserDNSearchBaseDistName = env.Get(EnvUserDNSearchBaseDN, kvs.Get(UserDNSearchBaseDN))
// Group search params configuration
grpSearchFilter := env.Get(EnvGroupSearchFilter, kvs.Get(GroupSearchFilter))
grpSearchBaseDN := env.Get(EnvGroupSearchBaseDN, kvs.Get(GroupSearchBaseDN))
l.GroupSearchFilter = env.Get(EnvGroupSearchFilter, kvs.Get(GroupSearchFilter))
l.GroupSearchBaseDistName = env.Get(EnvGroupSearchBaseDN, kvs.Get(GroupSearchBaseDN))
// Either all group params must be set or none must be set.
if (grpSearchFilter != "" && grpSearchBaseDN == "") || (grpSearchFilter == "" && grpSearchBaseDN != "") {
return l, errors.New("All group related parameters must be set")
}
if grpSearchFilter != "" {
l.GroupSearchFilter = grpSearchFilter
l.GroupSearchBaseDistName = grpSearchBaseDN
l.GroupSearchBaseDistNames = strings.Split(l.GroupSearchBaseDistName, dnDelimiter)
// Validate and test configuration.
valResult := l.Validate()
if !valResult.IsOk() {
return l, valResult
}
return l, nil

View File

@ -0,0 +1,331 @@
// Copyright (c) 2015-2022 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package ldap
import (
"crypto/tls"
"errors"
"fmt"
"net"
"strconv"
"strings"
"time"
ldap "github.com/go-ldap/ldap/v3"
"github.com/minio/minio-go/v7/pkg/set"
"github.com/minio/minio/internal/auth"
)
func getGroups(conn *ldap.Conn, sreq *ldap.SearchRequest) ([]string, error) {
var groups []string
sres, err := conn.Search(sreq)
if err != nil {
// Check if there is no matching result and return empty slice.
// Ref: https://ldap.com/ldap-result-code-reference/
if ldap.IsErrorWithCode(err, 32) {
return nil, nil
}
return nil, err
}
for _, entry := range sres.Entries {
// We only queried one attribute,
// so we only look up the first one.
groups = append(groups, entry.DN)
}
return groups, nil
}
func (l *Config) lookupBind(conn *ldap.Conn) error {
var err error
if l.LookupBindPassword == "" {
err = conn.UnauthenticatedBind(l.LookupBindDN)
} else {
err = conn.Bind(l.LookupBindDN, l.LookupBindPassword)
}
if ldap.IsErrorWithCode(err, 49) {
return fmt.Errorf("LDAP Lookup Bind user invalid credentials error: %w", err)
}
return err
}
// lookupUserDN searches for the DN of the user given their username. conn is
// assumed to be using the lookup bind service account. It is required that the
// search result in at most one result.
func (l *Config) lookupUserDN(conn *ldap.Conn, username string) (string, error) {
filter := strings.ReplaceAll(l.UserDNSearchFilter, "%s", ldap.EscapeFilter(username))
var foundDistNames []string
for _, userSearchBase := range l.UserDNSearchBaseDistNames {
searchRequest := ldap.NewSearchRequest(
userSearchBase,
ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
filter,
[]string{}, // only need DN, so no pass no attributes here
nil,
)
searchResult, err := conn.Search(searchRequest)
if err != nil {
return "", err
}
for _, entry := range searchResult.Entries {
foundDistNames = append(foundDistNames, entry.DN)
}
}
if len(foundDistNames) == 0 {
return "", fmt.Errorf("User DN for %s not found", username)
}
if len(foundDistNames) != 1 {
return "", fmt.Errorf("Multiple DNs for %s found - please fix the search filter", username)
}
return foundDistNames[0], nil
}
func (l *Config) searchForUserGroups(conn *ldap.Conn, username, bindDN string) ([]string, error) {
// User groups lookup.
var groups []string
if l.GroupSearchFilter != "" {
for _, groupSearchBase := range l.GroupSearchBaseDistNames {
filter := strings.ReplaceAll(l.GroupSearchFilter, "%s", ldap.EscapeFilter(username))
filter = strings.ReplaceAll(filter, "%d", ldap.EscapeFilter(bindDN))
searchRequest := ldap.NewSearchRequest(
groupSearchBase,
ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
filter,
nil,
nil,
)
var newGroups []string
newGroups, err := getGroups(conn, searchRequest)
if err != nil {
errRet := fmt.Errorf("Error finding groups of %s: %w", bindDN, err)
return nil, errRet
}
groups = append(groups, newGroups...)
}
}
return groups, nil
}
// LookupUserDN searches for the full DN and groups of a given username
func (l *Config) LookupUserDN(username string) (string, []string, error) {
conn, err := l.Connect()
if err != nil {
return "", nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// Lookup user DN
bindDN, err := l.lookupUserDN(conn, username)
if err != nil {
errRet := fmt.Errorf("Unable to find user DN: %w", err)
return "", nil, errRet
}
groups, err := l.searchForUserGroups(conn, username, bindDN)
if err != nil {
return "", nil, err
}
return bindDN, groups, nil
}
// Bind - binds to ldap, searches LDAP and returns the distinguished name of the
// user and the list of groups.
func (l *Config) Bind(username, password string) (string, []string, error) {
conn, err := l.Connect()
if err != nil {
return "", nil, err
}
defer conn.Close()
var bindDN string
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// Lookup user DN
bindDN, err = l.lookupUserDN(conn, username)
if err != nil {
errRet := fmt.Errorf("Unable to find user DN: %w", err)
return "", nil, errRet
}
// Authenticate the user credentials.
err = conn.Bind(bindDN, password)
if err != nil {
errRet := fmt.Errorf("LDAP auth failed for DN %s: %w", bindDN, err)
return "", nil, errRet
}
// Bind to the lookup user account again to perform group search.
if err = l.lookupBind(conn); err != nil {
return "", nil, err
}
// User groups lookup.
groups, err := l.searchForUserGroups(conn, username, bindDN)
if err != nil {
return "", nil, err
}
return bindDN, groups, nil
}
// Connect connect to ldap server.
func (l *Config) Connect() (ldapConn *ldap.Conn, err error) {
if l == nil {
return nil, errors.New("LDAP is not configured")
}
_, _, err = net.SplitHostPort(l.ServerAddr)
if err != nil {
// User default LDAP port if none specified "636"
l.ServerAddr = net.JoinHostPort(l.ServerAddr, "636")
}
if l.serverInsecure {
return ldap.Dial("tcp", l.ServerAddr)
}
tlsConfig := &tls.Config{
InsecureSkipVerify: l.tlsSkipVerify,
RootCAs: l.rootCAs,
}
if l.serverStartTLS {
conn, err := ldap.Dial("tcp", l.ServerAddr)
if err != nil {
return nil, err
}
err = conn.StartTLS(tlsConfig)
return conn, err
}
return ldap.DialTLS("tcp", l.ServerAddr, tlsConfig)
}
// GetExpiryDuration - return parsed expiry duration.
func (l Config) GetExpiryDuration(dsecs string) (time.Duration, error) {
if dsecs == "" {
return l.stsExpiryDuration, nil
}
d, err := strconv.Atoi(dsecs)
if err != nil {
return 0, auth.ErrInvalidDuration
}
dur := time.Duration(d) * time.Second
if dur < minLDAPExpiry || dur > maxLDAPExpiry {
return 0, auth.ErrInvalidDuration
}
return dur, nil
}
// IsLDAPUserDN determines if the given string could be a user DN from LDAP.
func (l Config) IsLDAPUserDN(user string) bool {
for _, baseDN := range l.UserDNSearchBaseDistNames {
if strings.HasSuffix(user, ","+baseDN) {
return true
}
}
return false
}
// GetNonEligibleUserDistNames - find user accounts (DNs) that are no longer
// present in the LDAP server or do not meet filter criteria anymore
func (l *Config) GetNonEligibleUserDistNames(userDistNames []string) ([]string, error) {
conn, err := l.Connect()
if err != nil {
return nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return nil, err
}
// Evaluate the filter again with generic wildcard instead of specific values
filter := strings.ReplaceAll(l.UserDNSearchFilter, "%s", "*")
nonExistentUsers := []string{}
for _, dn := range userDistNames {
searchRequest := ldap.NewSearchRequest(
dn,
ldap.ScopeBaseObject, ldap.NeverDerefAliases, 0, 0, false,
filter,
[]string{}, // only need DN, so pass no attributes here
nil,
)
searchResult, err := conn.Search(searchRequest)
if err != nil {
// Object does not exist error?
if ldap.IsErrorWithCode(err, 32) {
nonExistentUsers = append(nonExistentUsers, dn)
continue
}
return nil, err
}
if len(searchResult.Entries) == 0 {
// DN was not found - this means this user account is
// expired.
nonExistentUsers = append(nonExistentUsers, dn)
}
}
return nonExistentUsers, nil
}
// LookupGroupMemberships - for each DN finds the set of LDAP groups they are a
// member of.
func (l *Config) LookupGroupMemberships(userDistNames []string, userDNToUsernameMap map[string]string) (map[string]set.StringSet, error) {
conn, err := l.Connect()
if err != nil {
return nil, err
}
defer conn.Close()
// Bind to the lookup user account
if err = l.lookupBind(conn); err != nil {
return nil, err
}
res := make(map[string]set.StringSet, len(userDistNames))
for _, userDistName := range userDistNames {
username := userDNToUsernameMap[userDistName]
groups, err := l.searchForUserGroups(conn, username, userDistName)
if err != nil {
return nil, err
}
res[userDistName] = set.CreateStringSet(groups...)
}
return res, nil
}