From 5d6f77a33b3539e6eddb713c091cac26fccd31d9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Lapeyre?= Date: Fri, 20 May 2022 00:07:23 +0200 Subject: [PATCH] Fix handling of username_as_alias during LDAP authentication There is a bug that was introduced in the LDAP authentication method by https://github.com/hashicorp/vault/pull/11000. It was thought to be backward compatible but has broken a number of users. Later a new parameter `username_as_alias` was introduced in https://github.com/hashicorp/vault/pull/14324 to make it possible for operators to restore the previous behavior. The way it is currently working is not completely backward compatible thought because when username_as_alias is set, a call to GetUserAliasAttributeValue() will first be made, then this value is completely discarded in pathLogin() and replaced by the username as expected. This is an issue because it makes useless calls to the LDAP server and will break backward compatibility if one of the constraints in GetUserAliasAttributeValue() is not respected, even though the resulting value will be discarded anyway. In order to maintain backward compatibility here we have to only call GetUserAliasAttributeValue() if necessary. Since this change of behavior was introduced in 1.9, this fix will need to be backported to the 1.9, 1.10 and 1.11 branches. --- builtin/credential/ldap/backend.go | 17 ++++++++++------- builtin/credential/ldap/path_login.go | 8 ++------ 2 files changed, 12 insertions(+), 13 deletions(-) diff --git a/builtin/credential/ldap/backend.go b/builtin/credential/ldap/backend.go index 37ba20ae6c09e..94562723fa9b5 100644 --- a/builtin/credential/ldap/backend.go +++ b/builtin/credential/ldap/backend.go @@ -56,7 +56,7 @@ type backend struct { *framework.Backend } -func (b *backend) Login(ctx context.Context, req *logical.Request, username string, password string) (string, []string, *logical.Response, []string, error) { +func (b *backend) Login(ctx context.Context, req *logical.Request, username string, password string, usernameAsAlias bool) (string, []string, *logical.Response, []string, error) { cfg, err := b.Config(ctx, req) if err != nil { return "", nil, nil, nil, err @@ -195,12 +195,15 @@ func (b *backend) Login(ctx context.Context, req *logical.Request, username stri // Policies from each group may overlap policies = strutil.RemoveDuplicates(policies, true) - entityAliasAttribute, err := ldapClient.GetUserAliasAttributeValue(cfg.ConfigEntry, c, username) - if err != nil { - return "", nil, logical.ErrorResponse(err.Error()), nil, nil - } - if entityAliasAttribute == "" { - return "", nil, logical.ErrorResponse("missing entity alias attribute value"), nil, nil + entityAliasAttribute := username + if !usernameAsAlias { + entityAliasAttribute, err = ldapClient.GetUserAliasAttributeValue(cfg.ConfigEntry, c, username) + if err != nil { + return "", nil, logical.ErrorResponse(err.Error()), nil, nil + } + if entityAliasAttribute == "" { + return "", nil, logical.ErrorResponse("missing entity alias attribute value"), nil, nil + } } return entityAliasAttribute, policies, ldapResponse, allGroups, nil diff --git a/builtin/credential/ldap/path_login.go b/builtin/credential/ldap/path_login.go index 49c0cfe9d8fb1..67303911e5a17 100644 --- a/builtin/credential/ldap/path_login.go +++ b/builtin/credential/ldap/path_login.go @@ -73,7 +73,7 @@ func (b *backend) pathLogin(ctx context.Context, req *logical.Request, d *framew username := d.Get("username").(string) password := d.Get("password").(string) - effectiveUsername, policies, resp, groupNames, err := b.Login(ctx, req, username, password) + effectiveUsername, policies, resp, groupNames, err := b.Login(ctx, req, username, password, cfg.UsernameAsAlias) // Handle an internal error if err != nil { return nil, err @@ -103,10 +103,6 @@ func (b *backend) pathLogin(ctx context.Context, req *logical.Request, d *framew }, } - if cfg.UsernameAsAlias { - auth.Alias.Name = username - } - cfg.PopulateTokenAuth(auth) // Add in configured policies from mappings @@ -139,7 +135,7 @@ func (b *backend) pathLoginRenew(ctx context.Context, req *logical.Request, d *f username := req.Auth.Metadata["username"] password := req.Auth.InternalData["password"].(string) - _, loginPolicies, resp, groupNames, err := b.Login(ctx, req, username, password) + _, loginPolicies, resp, groupNames, err := b.Login(ctx, req, username, password, cfg.UsernameAsAlias) if err != nil || (resp != nil && resp.IsError()) { return resp, err }