Fix support for multiple LDAP user formats (#11276)

Fixes support for using multiple base DNs for user search in the LDAP directory
allowing users from different subtrees in the LDAP hierarchy to request
credentials.

- The username in the produced credentials is now the full DN of the LDAP user
to disambiguate users in different base DNs.
master
Aditya Manthramurthy 4 years ago committed by GitHub
parent 0dadfd1b3d
commit 3163a660aa
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  1. 157
      cmd/config/identity/ldap/config.go
  2. 2
      cmd/config/identity/ldap/legacy.go
  3. 8
      cmd/sts-handlers.go
  4. 2
      docs/sts/ldap.md

@ -45,15 +45,13 @@ type Config struct {
STSExpiryDuration string `json:"stsExpiryDuration"`
// Format string for usernames
UsernameFormat string `json:"usernameFormat"`
UsernameFormats []string `json:"-"`
UsernameSearchFilter string `json:"-"`
UsernameSearchBaseDNS []string `json:"-"`
UsernameFormat string `json:"usernameFormat"`
UsernameFormats []string `json:"-"`
GroupSearchBaseDN string `json:"groupSearchBaseDN"`
GroupSearchBaseDNS []string `json:"-"`
GroupSearchFilter string `json:"groupSearchFilter"`
GroupNameAttribute string `json:"groupNameAttribute"`
GroupSearchBaseDistName string `json:"groupSearchBaseDN"`
GroupSearchBaseDistNames []string `json:"-"`
GroupSearchFilter string `json:"groupSearchFilter"`
GroupNameAttribute string `json:"groupNameAttribute"`
stsExpiryDuration time.Duration // contains converted value
tlsSkipVerify bool // allows skipping TLS verification
@ -76,17 +74,15 @@ const (
ServerInsecure = "server_insecure"
ServerStartTLS = "server_starttls"
EnvServerAddr = "MINIO_IDENTITY_LDAP_SERVER_ADDR"
EnvSTSExpiry = "MINIO_IDENTITY_LDAP_STS_EXPIRY"
EnvTLSSkipVerify = "MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY"
EnvServerInsecure = "MINIO_IDENTITY_LDAP_SERVER_INSECURE"
EnvServerStartTLS = "MINIO_IDENTITY_LDAP_SERVER_STARTTLS"
EnvUsernameFormat = "MINIO_IDENTITY_LDAP_USERNAME_FORMAT"
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"
EnvServerAddr = "MINIO_IDENTITY_LDAP_SERVER_ADDR"
EnvSTSExpiry = "MINIO_IDENTITY_LDAP_STS_EXPIRY"
EnvTLSSkipVerify = "MINIO_IDENTITY_LDAP_TLS_SKIP_VERIFY"
EnvServerInsecure = "MINIO_IDENTITY_LDAP_SERVER_INSECURE"
EnvServerStartTLS = "MINIO_IDENTITY_LDAP_SERVER_STARTTLS"
EnvUsernameFormat = "MINIO_IDENTITY_LDAP_USERNAME_FORMAT"
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
@ -157,96 +153,82 @@ func getGroups(conn *ldap.Conn, sreq *ldap.SearchRequest) ([]string, error) {
return groups, nil
}
func (l *Config) bind(conn *ldap.Conn, username, password string) ([]string, error) {
var bindDNS = make([]string, len(l.UsernameFormats))
// bind - Iterates over all given username formats and expects that only one
// will succeed if the credentials are valid. The succeeding bindDN is returned
// or an error.
//
// In the rare case that multiple username formats succeed, implying that two
// (or more) distinct users in the LDAP directory have the same username and
// password, we return an error as we cannot identify the account intended by
// the user.
func (l *Config) bind(conn *ldap.Conn, username, password string) (string, error) {
var bindDistNames []string
var errs = make([]error, len(l.UsernameFormats))
var successCount = 0
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
errs[i] = conn.Bind(bindDN, password)
if errs[i] == nil {
bindDistNames = append(bindDistNames, bindDN)
successCount++
}
bindDNS[i] = bindDN
}
return bindDNS, nil
}
var standardAttributes = []string{
"givenName",
"sn",
"cn",
"memberOf",
"email",
if successCount == 0 {
var errStrings []string = []string{"All username formats failed with: "}
for _, err := range errs {
if err != nil {
errStrings = append(errStrings, err.Error())
}
}
outErr := strings.Join(errStrings, "; ")
return "", errors.New(outErr)
}
if successCount > 1 {
successDistNames := strings.Join(bindDistNames, ", ")
errMsg := fmt.Sprintf("Multiple username formats succeeded - ambiguous user login (succeeded for: %s)", successDistNames)
return "", errors.New(errMsg)
}
return bindDistNames[0], nil
}
// Bind - binds to ldap, searches LDAP and returns list of groups.
func (l *Config) Bind(username, password string) ([]string, error) {
// 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
return "", nil, err
}
defer conn.Close()
bindDNS, err := l.bind(conn, username, password)
bindDN, err := l.bind(conn, username, password)
if err != nil {
return nil, err
return "", nil, err
}
var groups []string
if l.UsernameSearchFilter != "" {
for _, userSearchBase := range l.UsernameSearchBaseDNS {
filter := strings.Replace(l.UsernameSearchFilter, "%s",
ldap.EscapeFilter(username), -1)
if l.GroupSearchFilter != "" {
for _, groupSearchBase := range l.GroupSearchBaseDistNames {
filter := strings.Replace(l.GroupSearchFilter, "%s", ldap.EscapeFilter(bindDN), -1)
searchRequest := ldap.NewSearchRequest(
userSearchBase,
groupSearchBase,
ldap.ScopeWholeSubtree, ldap.NeverDerefAliases, 0, 0, false,
filter,
standardAttributes,
[]string{l.GroupNameAttribute},
nil,
)
groups, err = getGroups(conn, searchRequest)
var newGroups []string
newGroups, err = getGroups(conn, searchRequest)
if err != nil {
return nil, err
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...)
}
groups = append(groups, newGroups...)
}
}
return groups, nil
return bindDN, groups, nil
}
// Connect connect to ldap server.
@ -343,17 +325,6 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
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))
@ -370,7 +341,7 @@ func Lookup(kvs config.KVS, rootCAs *x509.CertPool) (l Config, err error) {
if allSet {
l.GroupSearchFilter = grpSearchFilter
l.GroupNameAttribute = grpSearchNameAttr
l.GroupSearchBaseDNS = strings.Split(grpSearchBaseDN, dnDelimiter)
l.GroupSearchBaseDistNames = strings.Split(l.GroupSearchBaseDistName, dnDelimiter)
}
l.rootCAs = rootCAs

@ -47,7 +47,7 @@ func SetIdentityLDAP(s config.Config, ldapArgs Config) {
},
config.KV{
Key: GroupSearchBaseDN,
Value: ldapArgs.GroupSearchBaseDN,
Value: ldapArgs.GroupSearchBaseDistName,
},
}
}

@ -490,9 +490,9 @@ func (sts *stsAPIHandlers) AssumeRoleWithLDAPIdentity(w http.ResponseWriter, r *
}
}
groups, err := globalLDAPConfig.Bind(ldapUsername, ldapPassword)
ldapUserDN, groups, err := globalLDAPConfig.Bind(ldapUsername, ldapPassword)
if err != nil {
err = fmt.Errorf("LDAP server connection failure: %w", err)
err = fmt.Errorf("LDAP server error: %w", err)
writeSTSErrorResponse(ctx, w, true, ErrSTSInvalidParameterValue, err)
return
}
@ -500,7 +500,7 @@ func (sts *stsAPIHandlers) AssumeRoleWithLDAPIdentity(w http.ResponseWriter, r *
expiryDur := globalLDAPConfig.GetExpiryDuration()
m := map[string]interface{}{
expClaim: UTCNow().Add(expiryDur).Unix(),
ldapUser: ldapUsername,
ldapUser: ldapUserDN,
}
if len(sessionPolicyStr) > 0 {
@ -516,7 +516,7 @@ func (sts *stsAPIHandlers) AssumeRoleWithLDAPIdentity(w http.ResponseWriter, r *
// Set the parent of the temporary access key, this is useful
// in obtaining service accounts by this cred.
cred.ParentUser = ldapUsername
cred.ParentUser = ldapUserDN
// Set this value to LDAP groups, LDAP user can be part
// of large number of groups

@ -47,10 +47,8 @@ identity_ldap enable LDAP SSO support
ARGS:
MINIO_IDENTITY_LDAP_SERVER_ADDR* (address) AD/LDAP server address e.g. "myldapserver.com:636"
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_USERNAME_SEARCH_FILTER* (string) user search filter, for example "(cn=%s)" or "(sAMAccountName=%s)" or "(uid=%s)"
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)

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