Support multiple LDAP OU's, smAccountName support (#9139)

Fixes #8532

cmd/config-current.go

@@ -273,9 +273,19 @@ func validateConfig(s config.Config) error {
 		return err
 	}
 
-	if _, err := xldap.Lookup(s[config.IdentityLDAPSubSys][config.Default],
+	{
-		globalRootCAs); err != nil {
+		cfg, err := xldap.Lookup(s[config.IdentityLDAPSubSys][config.Default],
-		return err
+			globalRootCAs)
+		if err != nil {
+			return err
+		}
+		if cfg.Enabled {
+			conn, cerr := cfg.Connect()
+			if cerr != nil {
+				return cerr
+			}
+			conn.Close()
+		}
 	}
 
 	if _, err := opa.LookupConfig(s[config.PolicyOPASubSys][config.Default],

cmd/config/identity/ldap/config.go

@@ -21,7 +21,8 @@ import (
 	"crypto/x509"
 	"errors"
 	"fmt"
-	"regexp"
+	"net"
+	"strings"
 	"time"
 
 	"github.com/minio/minio/cmd/config"
@@ -44,11 +45,15 @@ type Config struct {
 	STSExpiryDuration string `json:"stsExpiryDuration"`
 
 	// Format string for usernames
-	UsernameFormat string `json:"usernameFormat"`
+	UsernameFormat        string   `json:"usernameFormat"`
+	UsernameFormats       []string `json:"-"`
+	UsernameSearchFilter  string   `json:"-"`
+	UsernameSearchBaseDNS []string `json:"-"`
 
-	GroupSearchBaseDN  string `json:"groupSearchBaseDN"`
+	GroupSearchBaseDN  string   `json:"groupSearchBaseDN"`
-	GroupSearchFilter  string `json:"groupSearchFilter"`
+	GroupSearchBaseDNS []string `json:"-"`
-	GroupNameAttribute string `json:"groupNameAttribute"`
+	GroupSearchFilter  string   `json:"groupSearchFilter"`
+	GroupNameAttribute string   `json:"groupNameAttribute"`
 
 	stsExpiryDuration time.Duration // contains converted value
 	tlsSkipVerify     bool          // allows skipping TLS verification
@@ -58,23 +63,27 @@ type Config struct {
 
 // LDAP keys and envs.
 const (
-	ServerAddr         = "server_addr"
+	ServerAddr           = "server_addr"
-	STSExpiry          = "sts_expiry"
+	STSExpiry            = "sts_expiry"
-	UsernameFormat     = "username_format"
+	UsernameFormat       = "username_format"
-	GroupSearchFilter  = "group_search_filter"
+	UsernameSearchFilter = "username_search_filter"
-	GroupNameAttribute = "group_name_attribute"
+	UsernameSearchBaseDN = "username_search_base_dn"
-	GroupSearchBaseDN  = "group_search_base_dn"
+	GroupSearchFilter    = "group_search_filter"
-	TLSSkipVerify      = "tls_skip_verify"
+	GroupNameAttribute   = "group_name_attribute"
-	ServerInsecure     = "server_insecure"
+	GroupSearchBaseDN    = "group_search_base_dn"
-
+	TLSSkipVerify        = "tls_skip_verify"
-	EnvServerAddr         = "MINIO_IDENTITY_LDAP_SERVER_ADDR"
+	ServerInsecure       = "server_insecure"
-	EnvSTSExpiry          = "MINIO_IDENTITY_LDAP_STS_EXPIRY"
+
-	EnvTLSSkipVerify      = "MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY"
+	EnvServerAddr           = "MINIO_IDENTITY_LDAP_SERVER_ADDR"
-	EnvServerInsecure     = "MINIO_IDENTITY_LDAP_SERVER_INSECURE"
+	EnvSTSExpiry            = "MINIO_IDENTITY_LDAP_STS_EXPIRY"
-	EnvUsernameFormat     = "MINIO_IDENTITY_LDAP_USERNAME_FORMAT"
+	EnvTLSSkipVerify        = "MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY"
-	EnvGroupSearchFilter  = "MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER"
+	EnvServerInsecure       = "MINIO_IDENTITY_LDAP_SERVER_INSECURE"
-	EnvGroupNameAttribute = "MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE"
+	EnvUsernameFormat       = "MINIO_IDENTITY_LDAP_USERNAME_FORMAT"
-	EnvGroupSearchBaseDN  = "MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN"
+	EnvUsernameSearchFilter = "MINIO_IDENTITY_LDAP_USERNAME_SEARCH_FILTER"
+	EnvUsernameSearchBaseDN = "MINIO_IDENTITY_LDAP_USERNAME_SEARCH_BASE_DN"
+	EnvGroupSearchFilter    = "MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER"
+	EnvGroupNameAttribute   = "MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE"
+	EnvGroupSearchBaseDN    = "MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN"
 )
 
 // DefaultKVS - default config for LDAP config
@@ -85,11 +94,15 @@ var (
 			Value: "",
 		},
 		config.KV{
-			Key:   STSExpiry,
+			Key:   UsernameFormat,
-			Value: "1h",
+			Value: "",
 		},
 		config.KV{
-			Key:   UsernameFormat,
+			Key:   UsernameSearchFilter,
+			Value: "",
+		},
+		config.KV{
+			Key:   UsernameSearchBaseDN,
 			Value: "",
 		},
 		config.KV{
@@ -104,6 +117,10 @@ var (
 			Key:   GroupSearchBaseDN,
 			Value: "",
 		},
+		config.KV{
+			Key:   STSExpiry,
+			Value: "1h",
+		},
 		config.KV{
 			Key:   TLSSkipVerify,
 			Value: config.EnableOff,
@@ -115,16 +132,131 @@ var (
 	}
 )
 
+const (
+	dnDelimiter = ";"
+)
+
+func getGroups(conn *ldap.Conn, sreq *ldap.SearchRequest) ([]string, error) {
+	var groups []string
+	sres, err := conn.Search(sreq)
+	if err != 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.Attributes[0].Values...)
+	}
+	return groups, nil
+}
+
+func (l *Config) bind(conn *ldap.Conn, username, password string) ([]string, error) {
+	var bindDNS = make([]string, len(l.UsernameFormats))
+	for i, usernameFormat := range l.UsernameFormats {
+		bindDN := fmt.Sprintf(usernameFormat, username)
+		// Bind with user credentials to validate the password
+		if err := conn.Bind(bindDN, password); err != nil {
+			return nil, err
+		}
+		bindDNS[i] = bindDN
+	}
+	return bindDNS, nil
+}
+
+var standardAttributes = []string{
+	"givenName",
+	"sn",
+	"cn",
+	"memberOf",
+	"email",
+}
+
+// Bind - binds to ldap, searches LDAP and returns list of groups.
+func (l *Config) Bind(username, password string) ([]string, error) {
+	conn, err := l.Connect()
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	bindDNS, err := l.bind(conn, username, password)
+	if err != nil {
+		return nil, err
+	}
+
+	var groups []string
+	if l.UsernameSearchFilter != "" {
+		for _, userSearchBase := range l.UsernameSearchBaseDNS {
+			filter := strings.Replace(l.UsernameSearchFilter, "%s",
+				ldap.EscapeFilter(username), -1)
+
+			searchRequest := ldap.NewSearchRequest(
+				userSearchBase,
+				ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
+				filter,
+				standardAttributes,
+				nil,
+			)
+
+			groups, err = getGroups(conn, searchRequest)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	if l.GroupSearchFilter != "" {
+		for _, groupSearchBase := range l.GroupSearchBaseDNS {
+			var filters []string
+			if l.GroupNameAttribute == "" {
+				filters = []string{strings.Replace(l.GroupSearchFilter, "%s",
+					ldap.EscapeFilter(username), -1)}
+			} else {
+				// With group name attribute specified, make sure to
+				// include search queries for CN distinguished name
+				for _, bindDN := range bindDNS {
+					filters = append(filters, strings.Replace(l.GroupSearchFilter, "%s",
+						ldap.EscapeFilter(bindDN), -1))
+				}
+			}
+			for _, filter := range filters {
+				searchRequest := ldap.NewSearchRequest(
+					groupSearchBase,
+					ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
+					filter,
+					standardAttributes,
+					nil,
+				)
+
+				var newGroups []string
+				newGroups, err = getGroups(conn, searchRequest)
+				if err != nil {
+					return nil, err
+				}
+
+				groups = append(groups, newGroups...)
+			}
+		}
+	}
+
+	return groups, nil
+}
+
 // Connect connect to ldap server.
 func (l *Config) Connect() (ldapConn *ldap.Conn, err error) {
 	if l == nil {
-		// Happens when LDAP is not configured.
+		return nil, errors.New("LDAP is not configured")
-		return
+	}
+
+	if _, _, err = net.SplitHostPort(l.ServerAddr); 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)
 	}
+
 	return ldap.DialTLS("tcp", l.ServerAddr, &tls.Config{
 		InsecureSkipVerify: l.tlsSkipVerify,
 		RootCAs:            l.rootCAs,
@@ -178,102 +310,44 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
 		}
 	}
 	if v := env.Get(EnvUsernameFormat, kvs.Get(UsernameFormat)); v != "" {
-		subs, err := NewSubstituter("username", "test")
+		if !strings.Contains(v, "%s") {
-		if err != nil {
+			return l, errors.New("LDAP username format doesn't have '%s' substitution")
-			return l, err
-		}
-		if _, err := subs.Substitute(v); err != nil {
-			return l, err
 		}
-		l.UsernameFormat = v
+		l.UsernameFormats = strings.Split(v, dnDelimiter)
 	} else {
 		return l, fmt.Errorf("'%s' cannot be empty and must have a value", UsernameFormat)
 	}
 
+	if v := env.Get(EnvUsernameSearchFilter, kvs.Get(UsernameSearchFilter)); v != "" {
+		if !strings.Contains(v, "%s") {
+			return l, errors.New("LDAP username search filter doesn't have '%s' substitution")
+		}
+		l.UsernameSearchFilter = v
+	}
+
+	if v := env.Get(EnvUsernameSearchBaseDN, kvs.Get(UsernameSearchBaseDN)); v != "" {
+		l.UsernameSearchBaseDNS = strings.Split(v, dnDelimiter)
+	}
+
 	grpSearchFilter := env.Get(EnvGroupSearchFilter, kvs.Get(GroupSearchFilter))
 	grpSearchNameAttr := env.Get(EnvGroupNameAttribute, kvs.Get(GroupNameAttribute))
 	grpSearchBaseDN := env.Get(EnvGroupSearchBaseDN, kvs.Get(GroupSearchBaseDN))
 
 	// Either all group params must be set or none must be set.
-	allNotSet := grpSearchFilter == "" && grpSearchNameAttr == "" && grpSearchBaseDN == ""
+	var allSet bool
-	allSet := grpSearchFilter != "" && grpSearchNameAttr != "" && grpSearchBaseDN != ""
+	if grpSearchFilter != "" {
-	if !allNotSet && !allSet {
+		if grpSearchNameAttr == "" || grpSearchBaseDN == "" {
-		return l, errors.New("All group related parameters must be set")
+			return l, errors.New("All group related parameters must be set")
+		}
+		allSet = true
 	}
 
 	if allSet {
-		subs, err := NewSubstituter("username", "test", "usernamedn", "test2")
-		if err != nil {
-			return l, err
-		}
-		if _, err := subs.Substitute(grpSearchFilter); err != nil {
-			return l, fmt.Errorf("Only username and usernamedn may be substituted in the group search filter string: %s", err)
-		}
 		l.GroupSearchFilter = grpSearchFilter
 		l.GroupNameAttribute = grpSearchNameAttr
-		subs, err = NewSubstituter("username", "test", "usernamedn", "test2")
+		l.GroupSearchBaseDNS = strings.Split(grpSearchBaseDN, dnDelimiter)
-		if err != nil {
-			return l, err
-		}
-		if _, err := subs.Substitute(grpSearchBaseDN); err != nil {
-			return l, fmt.Errorf("Only username and usernamedn may be substituted in the base DN string: %s", err)
-		}
-		l.GroupSearchBaseDN = grpSearchBaseDN
 	}
 
 	l.rootCAs = rootCAs
 	return l, nil
 }
-
-// Substituter - This type is to allow restricted runtime
-// substitutions of variables in LDAP configuration items during
-// runtime.
-type Substituter struct {
-	vals map[string]string
-}
-
-// NewSubstituter - sets up the substituter for usage, for e.g.:
-//
-//  subber := NewSubstituter("username", "john")
-func NewSubstituter(v ...string) (Substituter, error) {
-	if len(v)%2 != 0 {
-		return Substituter{}, errors.New("Need an even number of arguments")
-	}
-	vals := make(map[string]string)
-	for i := 0; i < len(v); i += 2 {
-		vals[v[i]] = v[i+1]
-	}
-	return Substituter{vals: vals}, nil
-}
-
-// Substitute - performs substitution on the given string `t`. Returns
-// an error if there are any variables in the input that do not have
-// values in the substituter. E.g.:
-//
-// subber.Substitute("uid=${username},cn=users,dc=example,dc=com")
-//
-// or
-//
-// subber.Substitute("uid={username},cn=users,dc=example,dc=com")
-//
-// returns "uid=john,cn=users,dc=example,dc=com"
-//
-// whereas:
-//
-// subber.Substitute("uid=${usernamedn}")
-//
-// returns an error.
-func (s *Substituter) Substitute(t string) (string, error) {
-	for k, v := range s.vals {
-		reDollar := regexp.MustCompile(fmt.Sprintf(`\$\{%s\}`, k))
-		t = reDollar.ReplaceAllLiteralString(t, v)
-		reFlower := regexp.MustCompile(fmt.Sprintf(`\{%s\}`, k))
-		t = reFlower.ReplaceAllLiteralString(t, v)
-	}
-	// Check if all requested substitutions have been made.
-	re := regexp.MustCompile(`\{.*\}`)
-	if re.MatchString(t) {
-		return "", errors.New("unsupported substitution requested")
-	}
-	return t, nil
-}

cmd/config/identity/ldap/config_test.go

@@ -1,93 +0,0 @@
-/*
- * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ldap
-
-import (
-	"testing"
-)
-
-func TestSubstituter(t *testing.T) {
-	tests := []struct {
-		KV               []string
-		SubstitutableStr string
-		SubstitutedStr   string
-		ErrExpected      bool
-	}{
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "uid=${username},cn=users,dc=example,dc=com",
-			SubstitutedStr:   "uid=john,cn=users,dc=example,dc=com",
-			ErrExpected:      false,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "uid={username},cn=users,dc=example,dc=com",
-			SubstitutedStr:   "uid=john,cn=users,dc=example,dc=com",
-			ErrExpected:      false,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "(&(objectclass=group)(member=${username}))",
-			SubstitutedStr:   "(&(objectclass=group)(member=john))",
-			ErrExpected:      false,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "(&(objectclass=group)(member={username}))",
-			SubstitutedStr:   "(&(objectclass=group)(member=john))",
-			ErrExpected:      false,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "uid=${{username}},cn=users,dc=example,dc=com",
-			ErrExpected:      true,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "uid=${usernamedn},cn=users,dc=example,dc=com",
-			ErrExpected:      true,
-		},
-		{
-			KV:               []string{"username"},
-			SubstitutableStr: "uid=${usernamedn},cn=users,dc=example,dc=com",
-			ErrExpected:      true,
-		},
-		{
-			KV:               []string{"username", "john"},
-			SubstitutableStr: "(&(objectclass=user)(sAMAccountName={username})(memberOf=CN=myorg,OU=Rialto,OU=Application Managed,OU=Groups,DC=amr,DC=corp,DC=myorg,DC=com))",
-			SubstitutedStr:   "(&(objectclass=user)(sAMAccountName=john)(memberOf=CN=myorg,OU=Rialto,OU=Application Managed,OU=Groups,DC=amr,DC=corp,DC=myorg,DC=com))",
-			ErrExpected:      false,
-		},
-	}
-
-	for _, test := range tests {
-		test := test
-		t.Run(test.SubstitutableStr, func(t *testing.T) {
-			subber, err := NewSubstituter(test.KV...)
-			if err != nil && !test.ErrExpected {
-				t.Errorf("Unexpected failure %s", err)
-			}
-			gotStr, err := subber.Substitute(test.SubstitutableStr)
-			if err != nil && !test.ErrExpected {
-				t.Errorf("Unexpected failure %s", err)
-			}
-			if gotStr != test.SubstitutedStr {
-				t.Errorf("Expected %s, got %s", test.SubstitutedStr, gotStr)
-			}
-		})
-	}
-}

cmd/config/identity/ldap/help.go

@@ -28,24 +28,33 @@ var (
 		},
 		config.HelpKV{
 			Key:         UsernameFormat,
-			Description: `username bind DNs e.g. "uid=%s,cn=accounts,dc=myldapserver,dc=com"`,
+			Description: `";" separated list of username bind DNs e.g. "uid=%s,cn=accounts,dc=myldapserver,dc=com"`,
+			Type:        "list",
+		},
+		config.HelpKV{
+			Key:         UsernameSearchFilter,
+			Description: `user search filter, for example "(cn=%s)" or "(sAMAccountName=%s)" or "(uid=%s)"`,
 			Type:        "string",
 		},
 		config.HelpKV{
 			Key:         GroupSearchFilter,
 			Description: `search filter for groups e.g. "(&(objectclass=groupOfNames)(memberUid=%s))"`,
-			Optional:    true,
 			Type:        "string",
 		},
 		config.HelpKV{
-			Key:         GroupNameAttribute,
+			Key:         GroupSearchBaseDN,
-			Description: `search attribute for group name e.g. "cn"`,
+			Description: `";" separated list of group search base DNs e.g. "dc=myldapserver,dc=com"`,
+			Type:        "list",
+		},
+		config.HelpKV{
+			Key:         UsernameSearchBaseDN,
+			Description: `";" separated list of username search DNs`,
+			Type:        "list",
 			Optional:    true,
-			Type:        "string",
 		},
 		config.HelpKV{
-			Key:         GroupSearchBaseDN,
+			Key:         GroupNameAttribute,
-			Description: `group search base DNs e.g. "dc=myldapserver,dc=com"`,
+			Description: `search attribute for group name e.g. "cn"`,
 			Optional:    true,
 			Type:        "string",
 		},
@@ -63,7 +72,7 @@ var (
 		},
 		config.HelpKV{
 			Key:         ServerInsecure,
-			Description: `allow plain text connection to AD/LDAP server, defaults to "off" (TLS)`,
+			Description: `allow plain text connection to AD/LDAP server, defaults to "off"`,
 			Optional:    true,
 			Type:        "on|off",
 		},

cmd/iam.go

@@ -369,6 +369,10 @@ func (sys *IAMSys) Init(objAPI ObjectLayer) error {
 		return errServerNotInitialized
 	}
 
+	if globalLDAPConfig.Enabled {
+		sys.EnableLDAPSys()
+	}
+
 	sys.Lock()
 	if globalEtcdClient == nil {
 		sys.store = newIAMObjectStore()
@@ -1791,22 +1795,18 @@ func (sys *IAMSys) removeGroupFromMembershipsMap(group string) {
 	}
 }
 
+// EnableLDAPSys - enable ldap system users type.
+func (sys *IAMSys) EnableLDAPSys() {
+	sys.Lock()
+	defer sys.Unlock()
+
+	sys.usersSysType = LDAPUsersSysType
+}
+
 // NewIAMSys - creates new config system object.
 func NewIAMSys() *IAMSys {
-	// Check global server configuration to determine the type of
-	// users system configured.
-
-	// The default users system
-	var utype UsersSysType
-	switch {
-	case globalLDAPConfig.Enabled:
-		utype = LDAPUsersSysType
-	default:
-		utype = MinIOUsersSysType
-	}
-
 	return &IAMSys{
-		usersSysType:            utype,
+		usersSysType:            MinIOUsersSysType,
 		iamUsersMap:             make(map[string]auth.Credentials),
 		iamPolicyDocsMap:        make(map[string]iampolicy.Policy),
 		iamUserPolicyMap:        make(map[string]MappedPolicy),

cmd/sts-handlers.go

@@ -24,14 +24,12 @@ import (
 	"net/http"
 
 	"github.com/gorilla/mux"
-	xldap "github.com/minio/minio/cmd/config/identity/ldap"
 	"github.com/minio/minio/cmd/config/identity/openid"
 	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/auth"
 	iampolicy "github.com/minio/minio/pkg/iam/policy"
 	"github.com/minio/minio/pkg/wildcard"
-	ldap "gopkg.in/ldap.v3"
 )
 
 const (
@@ -477,61 +475,13 @@ func (sts *stsAPIHandlers) AssumeRoleWithLDAPIdentity(w http.ResponseWriter, r *
 		}
 	}
 
-	ldapConn, err := globalLDAPConfig.Connect()
+	groups, err := globalLDAPConfig.Bind(ldapUsername, ldapPassword)
 	if err != nil {
-		writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, fmt.Errorf("LDAP server connection failure: %w", err))
+		err = fmt.Errorf("LDAP server connection failure: %w", err)
-		return
-	}
-	if ldapConn == nil {
-		writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, fmt.Errorf("LDAP server not configured: %w", err))
-		return
-	}
-
-	// Close ldap connection to avoid leaks.
-	defer ldapConn.Close()
-
-	usernameSubs, _ := xldap.NewSubstituter("username", ldapUsername)
-	// We ignore error below as we already validated the username
-	// format string at startup.
-	usernameDN, _ := usernameSubs.Substitute(globalLDAPConfig.UsernameFormat)
-	// Bind with user credentials to validate the password
-	if err = ldapConn.Bind(usernameDN, ldapPassword); err != nil {
-		err = fmt.Errorf("LDAP authentication failure: %w", err)
 		writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, err)
 		return
 	}
 
-	groups := []string{}
-	if globalLDAPConfig.GroupSearchFilter != "" {
-		// Verified user credentials. Now we find the groups they are
-		// a member of.
-		searchSubs, _ := xldap.NewSubstituter(
-			"username", ldapUsername,
-			"usernamedn", usernameDN,
-		)
-		// We ignore error below as we already validated the search string
-		// at startup.
-		groupSearchFilter, _ := searchSubs.Substitute(globalLDAPConfig.GroupSearchFilter)
-		baseDN, _ := searchSubs.Substitute(globalLDAPConfig.GroupSearchBaseDN)
-		searchRequest := ldap.NewSearchRequest(
-			baseDN,
-			ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
-			groupSearchFilter,
-			[]string{globalLDAPConfig.GroupNameAttribute},
-			nil,
-		)
-
-		sr, err := ldapConn.Search(searchRequest)
-		if err != nil {
-			writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, fmt.Errorf("LDAP search failure: %w", err))
-			return
-		}
-		for _, entry := range sr.Entries {
-			// We only queried one attribute, so we only look up
-			// the first one.
-			groups = append(groups, entry.Attributes[0].Values...)
-		}
-	}
 	expiryDur := globalLDAPConfig.GetExpiryDuration()
 	m := map[string]interface{}{
 		expClaim:   UTCNow().Add(expiryDur).Unix(),

docs/sts/ldap.md

@@ -38,45 +38,45 @@ LDAP configuration is designed to be simple for the MinIO administrator. The ful
 
 MinIO can be configured to find the groups of a user from AD/LDAP by specifying the **MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER** and **MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE** environment variables. When a user logs in via the STS API, the MinIO server queries the AD/LDAP server with the given search filter and extracts the given attribute from the search results. These values represent the groups that the user is a member of. On each access MinIO applies the IAM policies attached to these groups in MinIO.
 
+MinIO sends LDAP credentials to LDAP server for validation. So we _strongly recommend_ to use MinIO with AD/LDAP server over TLS _only_. Using plain-text connection between MinIO and LDAP server means _credentials can be compromised_ by anyone listening to network traffic.
+
 LDAP is configured via the following environment variables:
 
-| Variable                                     | Required?               | Purpose                                                                 |
+```
-|----------------------------------------------|-------------------------|-------------------------------------------------------------------------|
+$ mc admin config set myminio/ identity_ldap  --env
-| **MINIO_IDENTITY_LDAP_SERVER_ADDR**          | **YES**                 | AD/LDAP server address                                                  |
+KEY:
-| **MINIO_IDENTITY_LDAP_USERNAME_FORMAT**      | **YES**                 | Format of full username DN                                              |
+identity_ldap  enable LDAP SSO support
-| **MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN** | **NO**                  | Base DN in AD/LDAP hierarchy to use in search requests                  |
+
-| **MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER**  | **NO**                  | Search filter to find groups of a user                                  |
+ARGS:
-| **MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE** | **NO**                  | Attribute of search results to use as group name                        |
+MINIO_IDENTITY_LDAP_SERVER_ADDR*             (address)   AD/LDAP server address e.g. "myldapserver.com:636"
-| **MINIO_IDENTITY_LDAP_STS_EXPIRY**           | **NO** (default: "1h")  | STS credentials validity duration                                       |
+MINIO_IDENTITY_LDAP_USERNAME_FORMAT*         (list)      ";" separated list of username bind DNs e.g. "uid=%s,cn=accounts,dc=myldapserver,dc=com"
-| **MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY**      | **NO** (default: "off") | Set this to 'on', to disable client verification of server certificates |
+MINIO_IDENTITY_LDAP_USERNAME_SEARCH_FILTER*  (string)    user search filter, for example "(cn=%s)" or "(sAMAccountName=%s)" or "(uid=%s)"
-| **MINIO_IDENTITY_LDAP_SERVER_INSECURE**      | **NO** (default: "off") | Set this to 'on', to allow plain text connection to LDAP/AD Server (only for testing) |
+MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER*     (string)    search filter for groups e.g. "(&(objectclass=groupOfNames)(memberUid=%s))"
+MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN*    (list)      ";" separated list of group search base DNs e.g. "dc=myldapserver,dc=com"
+MINIO_IDENTITY_LDAP_USERNAME_SEARCH_BASE_DN  (list)      ";" separated list of username search DNs
+MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE     (string)    search attribute for group name e.g. "cn"
+MINIO_IDENTITY_LDAP_STS_EXPIRY               (duration)  temporary credentials validity duration in s,m,h,d. Default is "1h"
+MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY          (on|off)    trust server TLS without verification, defaults to "off" (verify)
+MINIO_IDENTITY_LDAP_SERVER_INSECURE          (on|off)    allow plain text connection to AD/LDAP server, defaults to "off"
+MINIO_IDENTITY_LDAP_COMMENT                  (sentence)  optionally add a comment to this setting
+```
 
 MinIO sends LDAP credentials to LDAP server for validation. So we _strongly recommend_ to use MinIO with AD/LDAP server over TLS _only_. Using plain-text connection between MinIO and LDAP server means _credentials can be compromised_ by anyone listening to network traffic.
 
 If a self-signed certificate is being used, the certificate can be added to MinIO's certificates directory, so it can be trusted by the server. An example setup for development or experimentation:
 
-``` shell
+```shell
 export MINIO_IDENTITY_LDAP_SERVER_ADDR=myldapserver.com:636
-export MINIO_IDENTITY_LDAP_USERNAME_FORMAT="uid={username},cn=accounts,dc=myldapserver,dc=com"
+export MINIO_IDENTITY_LDAP_USERNAME_FORMAT="uid=%s,cn=accounts,dc=myldapserver,dc=com"
 export MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN="dc=myldapserver,dc=com"
-export MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER="(&(objectclass=groupOfNames)(member={usernamedn})$)"
+export MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER="(&(objectclass=groupOfNames)(memberUid=%s)$)"
-export MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE="cn"
+export MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE=cn
 export MINIO_IDENTITY_LDAP_STS_EXPIRY=60h
-export MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY="on"
+export MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY=on
 ```
 
 ### Variable substitution in AD/LDAP configuration strings
-
+`%s` is replaced with *username* automatically for construction bind_dn, search_filter and group_search_filter.
-In the configuration values described above, some values support runtime substitutions. The substitution syntax is simply `${variable}` - this substring is replaced with the (string) value of `variable`. The following substitutions will be available:
-
-| Variable     | Example Runtime Value                          | Description                                                                                                                                  |
-|--------------|------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
-| *username*   | "james"                                        | The AD/LDAP username of a user.                                                                                                                 |
-| *usernamedn* | "uid=james,cn=accounts,dc=myldapserver,dc=com" | The AD/LDAP username DN of a user. This is constructed from the AD/LDAP user DN format string provided to the server and the actual AD/LDAP username. |
-
-The **MINIO_IDENTITY_LDAP_USERNAME_FORMAT** environment variable supports substitution of the *username* variable only.
-
-The **MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER** and **MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN** environment variables support substitution of the *username* and *usernamedn* variables only.
 
 ### Notes on configuring with Microsoft Active Directory (AD)
 
@@ -102,19 +102,19 @@ member: CN=John,CN=Users,DC=minioad,DC=local
 ...
 ```
 
-The lines with "..." represent skipped content not shown here from brevity. Based on the output above, we see that the username format variable looks like `cn={username},cn=users,dc=minioad,dc=local`.
+The lines with "..." represent skipped content not shown here from brevity. Based on the output above, we see that the username format variable looks like `cn=%s,cn=users,dc=minioad,dc=local`.
 
-The group search filter looks like `(&(objectclass=group)(member={usernamedn}))` and the group name attribute is clearly `cn`.
+The group search filter looks like `(&(objectclass=group)(memberUid=%s))` and the group name attribute is clearly `cn`.
 
 Thus the key configuration parameters look like:
 
 ```
 MINIO_IDENTITY_LDAP_SERVER_ADDR='my.ldap-active-dir-server.com:636'
-MINIO_IDENTITY_LDAP_USERNAME_FORMAT='cn={username},cn=users,dc=minioad,dc=local'
+MINIO_IDENTITY_LDAP_USERNAME_FORMAT='cn=%s,ou=Users,ou=BUS1,ou=LOB,dc=somedomain,dc=com'
 MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN='dc=minioad,dc=local'
-MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER='(&(objectclass=group)(member={usernamedn}))'
+MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER='(&(objectclass=group)(member=%s))'
 MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE='cn'
-MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY="on"
+MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY=on
 ```
 
 ## Managing User/Group Access Policy
@@ -212,13 +212,15 @@ http://minio.cluster:9000?Action=AssumeRoleWithLDAPIdentity&LDAPUsername=foouser
 ```
 
 ## Testing
+
+With multiple OU heirarchies for users, and multiple group search base DN's.
 ```
 $ export MINIO_ACCESS_KEY=minio
 $ export MINIO_SECRET_KEY=minio123
 $ export MINIO_IDENTITY_LDAP_SERVER_ADDR='my.ldap-active-dir-server.com:636'
-$ export MINIO_IDENTITY_LDAP_USERNAME_FORMAT='cn={username},cn=users,dc=minioad,dc=local'
+$ export MINIO_IDENTITY_LDAP_USERNAME_FORMAT='cn=%s,ou=Users,ou=BUS1,ou=LOB,dc=somedomain,dc=com;cn=%s,ou=Users,ou=BUS2,ou=LOB,dc=somedomain,dc=com'
-$ export MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN='dc=minioad,dc=local'
+$ export MINIO_IDENTITY_LDAP_GROUP_SEARCH_BASE_DN='dc=minioad,dc=local;dc=somedomain,dc=com'
-$ export MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER='(&(objectclass=group)(member={usernamedn}))'
+$ export MINIO_IDENTITY_LDAP_GROUP_SEARCH_FILTER='(&(objectclass=group)(member=%s))'
 $ export MINIO_IDENTITY_LDAP_GROUP_NAME_ATTRIBUTE='cn'
 $ minio server ~/test
 ```