Add {dn} as an available matcher in LDAP groups filter

Sometimes, LDAP organization is such that groups membership cannot be computed
with username only. User DN is required to retrieve groups.

e.g. user Joe has a username joe and a cn of Joe Blogs, resulting in a dn of
cn=Joe Blogs,ou=users,dc=example,dc=com which is needed to retrieve groups
but cannot be computed from joe only.

Issue was reported in issue #146

config.template.yml

@@ -33,8 +33,9 @@ ldap:
 
   # The groups filter used for retrieving groups of a given user.
   # {0} is a matcher replaced by username.
-  # 'member=cn={0},<additional_users_dn>,<base_dn>' by default.
-  groups_filter: (&(member=cn={0},ou=users,dc=example,dc=com)(objectclass=groupOfNames))
+  # {dn} is a matcher replaced by user DN.
+  # 'member={dn}' by default.
+  groups_filter: (&(member={dn})(objectclass=groupOfNames))
 
   # The attribute holding the name of the group
   group_name_attribute: cn

config.test.yml

@@ -33,8 +33,9 @@ ldap:
 
   # The groups filter used for retrieving groups of a given user.
   # {0} is a matcher replaced by username.
-  # 'member=cn={0},<additional_users_dn>,<base_dn>' by default.
-  groups_filter: (&(member=cn={0},ou=users,dc=example,dc=com)(objectclass=groupOfNames))
+  # {dn} is a matcher replaced by user DN.
+  # 'member={dn}' by default.
+  groups_filter: (&(member={dn})(objectclass=groupOfNames))
 
   # The attribute holding the name of the group
   group_name_attribute: cn

server/src/lib/configuration/ConfigurationParser.ts

@@ -29,10 +29,7 @@ function ensure_key_existence(config: object, path: string): void {
 
 function adaptLdapConfiguration(userConfig: UserLdapConfiguration): LdapConfiguration {
   const DEFAULT_USERS_FILTER = "cn={0}";
-  const DEFAULT_GROUPS_FILTER =
-    userConfig.additional_users_dn
-      ? Util.format("member=cn={0},%s,%s", userConfig.additional_groups_dn, userConfig.base_dn)
-      : Util.format("member=cn={0},%s", userConfig.base_dn);
+  const DEFAULT_GROUPS_FILTER = "member={dn}";
   const DEFAULT_GROUP_NAME_ATTRIBUTE = "cn";
   const DEFAULT_MAIL_ATTRIBUTE = "mail";
 

server/src/lib/ldap/Client.ts

@@ -47,18 +47,34 @@ export class Client implements IClient {
       });
   }
 
+  private createGroupsFilter(userGroupsFilter: string, username: string): BluebirdPromise<string> {
+    if (userGroupsFilter.indexOf("{0}") > 0) {
+      return BluebirdPromise.resolve(userGroupsFilter.replace("{0}", username));
+    }
+    else if (userGroupsFilter.indexOf("{dn}") > 0) {
+      return this.searchUserDn(username)
+        .then(function (userDN: string) {
+          return BluebirdPromise.resolve(userGroupsFilter.replace("{dn}", userDN));
+        });
+    }
+    return BluebirdPromise.resolve(userGroupsFilter);
+  }
+
   searchGroups(username: string): BluebirdPromise<string[]> {
     const that = this;
-    const filter = that.options.groups_filter.replace("{0}", username);
-    const query = {
-      scope: "sub",
-      attributes: [that.options.group_name_attribute],
-      filter: filter
-    };
-    return this.ldapClient.searchAsync(that.options.groups_dn, query)
+    return this.createGroupsFilter(this.options.groups_filter, username)
+      .then(function (groupsFilter: string) {
+        that.logger.debug("Computed groups filter is %s", groupsFilter);
+        const query = {
+          scope: "sub",
+          attributes: [that.options.group_name_attribute],
+          filter: groupsFilter
+        };
+        return that.ldapClient.searchAsync(that.options.groups_dn, query);
+      })
       .then(function (docs: { cn: string }[]) {
         const groups = docs.map((doc: any) => { return doc.cn; });
-        that.logger.debug("LDAP: groups of user %s are %s", username, groups);
+        that.logger.debug("LDAP: groups of user %s are [%s]", username, groups.join(","));
         return BluebirdPromise.resolve(groups);
       });
   }
@@ -66,6 +82,7 @@ export class Client implements IClient {
   searchUserDn(username: string): BluebirdPromise<string> {
     const that = this;
     const filter = this.options.users_filter.replace("{0}", username);
+    this.logger.debug("Computed users filter is %s", filter);
     const query = {
       scope: "sub",
       sizeLimit: 1,

server/src/lib/routes/verify/get.ts

@@ -45,7 +45,7 @@ function verify_filter(req: express.Request, res: express.Response): BluebirdPro
 
       const isAllowed = accessController.isAccessAllowed(domain, path, username, groups);
       if (!isAllowed) return BluebirdPromise.reject(
-        new exceptions.DomainAccessDenied(Util.format("User '%s' does not have access to '%'",
+        new exceptions.DomainAccessDenied(Util.format("User '%s' does not have access to '%s'",
           username, domain)));
 
       if (authenticationMethod == "two_factor" && !authSession.second_factor)

server/test/configuration/LdapConfigurationAdaptation.test.ts

@@ -56,7 +56,7 @@ describe("test ldap configuration adaptation", function () {
       users_dn: "dc=example,dc=com",
       users_filter: "cn={0}",
       groups_dn: "dc=example,dc=com",
-      groups_filter: "member=cn={0},dc=example,dc=com",
+      groups_filter: "member={dn}",
       group_name_attribute: "cn",
       mail_attribute: "mail",
       user: "admin",

server/test/ldap/Client.test.ts

@@ -31,9 +31,9 @@ describe("test authelia ldap client", function () {
     const ldapClient = new LdapClientStub();
 
     factory.createStub.returns(ldapClient);
-    ldapClient.searchAsyncStub.returns(BluebirdPromise.resolve([
-      "group1"
-    ]));
+    ldapClient.searchAsyncStub.returns(BluebirdPromise.resolve([{
+      cn: "group1"
+    }]));
     const client = new Client(ADMIN_USER_DN, ADMIN_PASSWORD, options, factory, Dovehash, Winston);
 
     return client.searchGroups("user1")
@@ -42,4 +42,49 @@ describe("test authelia ldap client", function () {
           "member=cn=user1,ou=users,dc=example,dc=com");
       });
   });
+
+  it("should replace {dn} by user DN when searching for groups in LDAP", function () {
+    const USER_DN = "cn=user1,ou=users,dc=example,dc=com";
+    const options: LdapConfiguration = {
+      url: "ldap://ldap",
+      users_dn: "ou=users,dc=example,dc=com",
+      users_filter: "cn={0}",
+      groups_dn: "ou=groups,dc=example,dc=com",
+      groups_filter: "member={dn}",
+      group_name_attribute: "cn",
+      mail_attribute: "mail",
+      user: "cn=admin,dc=example,dc=com",
+      password: "password"
+    };
+    const factory = new LdapClientFactoryStub();
+    const ldapClient = new LdapClientStub();
+
+    factory.createStub.returns(ldapClient);
+
+    // Retrieve user DN
+    ldapClient.searchAsyncStub.withArgs("ou=users,dc=example,dc=com", {
+      scope: "sub",
+      sizeLimit: 1,
+      attributes: ["dn"],
+      filter: "cn=user1"
+    }).returns(BluebirdPromise.resolve([{
+      dn: USER_DN
+    }]));
+
+    // Retrieve groups
+    ldapClient.searchAsyncStub.withArgs("ou=groups,dc=example,dc=com", {
+      scope: "sub",
+      attributes: ["cn"],
+      filter: "member=" + USER_DN
+    }).returns(BluebirdPromise.resolve([{
+      cn: "group1"
+    }]));
+
+    const client = new Client(ADMIN_USER_DN, ADMIN_PASSWORD, options, factory, Dovehash, Winston);
+
+    return client.searchGroups("user1")
+      .then(function (groups: string[]) {
+        Assert.deepEqual(groups, ["group1"]);
+      });
+  });
 });