Rework configuration file format.

The "users" entry is now a dictionary mapping user names to passwords and permissions. In order to allow for wildcards, there is a new type of password, the wildcard password, and an extra array called "fallback-users". The field "allow-anonymous" no longer exists, this is now the default behaviour. The field "allow-subgroups" has been renamed to "auto-subgroups". We provide backwards compatibility for group definition files, but not for the config.json file, where the old "admin" array is simply ignored.
2024-01-02 18:36:09 +01:00 · 2024-01-02 18:36:09 +01:00 · d887a216f0
parent eb54f2a9bb
commit d887a216f0
10 changed files with 571 additions and 204 deletions
--- a/106
+++ b/106
@ -66,14 +66,15 @@ The server may be configured in the JSON file `data/config.json`.  This
 file may look as follows:

    {
-        "admin":[{"username":"root","password":"secret"}],
+        "users":{"root": {"password":"secret", "permissions": "admin"}},
        "canonicalHost": "galene.example.org"
    }

 The fields are as follows:

- `admin` defines the users allowed to look at the `/stats.html` file; it
-  has the same syntax as user definitions in groups (see below).
+- `users` defines the users allowed to administer the server, and has the
+  same syntax as user definitions in groups (see below), except that the
+  only meaningful permission is `"admin"`;
 - `publicServer`: if true, then cross-origin access to the server is
  allowed.  This is safe if the server is on the public Internet, but not
  necessarily so if it is on a private network.
@ -100,38 +101,45 @@ a file `groups/teaching/networking.json` defines a group called
 A typical group definition file looks like this:

    {
-        "op":[{"username":"jch","password":"1234"}],
+        "users":{
+            "jch": {"password":"1234", "permissions": "op"}
+        },
        "allow-recording": true,
-        "allow-subgroups": true
+        "auto-subgroups": true
    }

 This defines a group with the operator (administrator) username *jch* and
 password *1234*.  The `allow-recording` entry says that the operator is
-allowed to record videos to disk, and the `allow-subgroups` entry says
+allowed to record videos to disk, and the `auto-subgroups` entry says
 that subgroups will be created automatically.  This particular group does
 not allow password login for ordinary users, and is suitable if you use
 invitations (see *Stateful Tokens* below) for ordinary users.

-In order to allow password login for ordinary users, add a list of users
-as the entry `presenter`:
+In order to allow password login for ordinary users, add password entries
+with the permission `present`:

    {
-        "op": [{"username":"jch","password":"1234"}],
-        "presenter": [{"username":"john", "password": "secret"}]
+        "users":{
+            "jch":  {"password":"1234", "permissions": "op"}
+            "john": {"password": "secret", "permissions": "present"}
+        }
    }

 If the group is to be publicly accessible, you may allow logins with any
-username and an empty password:
+username using the `fallback-users` entry::

    {
-        "op": [{"username":"jch","password":"1234"}],
-        "presenter": [{}],
+        "users":{
+            "jch": {"password":"1234", "permissions": "op"}
+        },
+        "fallback-users": [
+            {"password": {"type": "wildcard"}, "permissions": "present"}
+        ],
        "public": true
    }

-The empty dictionary `{}` is a wildcard entry: it matches any username and
-any password.  Setting `public` causes the group to be displayed in the
-list of public groups on the landing page
+The password `{"type": "wildcard"}` indicates that any password will be
+accepted.


 ## Reference
@ -141,10 +149,12 @@ entries between `{' and `}').  All fields are optional, but unless you
 specify at least one user definition (`op`, `presenter`, or `other`),
 nobody will be able to join the group.  The following fields are allowed:

- - `op`, `presenter`, `other`: each of these is an array of user
-   definitions (see *Authorisation* below) and specifies the users allowed
-   to connect respectively with operator privileges, with presenter
-   privileges, and as passive listeners;
+ - `users`: is a dictionary that maps user names to dictionaries with
+   entries `password` and `permissions`; `permissions` should be one of
+   `op`, `present` or `passive`;
+ - `fallback-users` is an array of dictionaries with entries `password`
+   and `permissions` that will be used for usernames with no matching
+   entry in the `users` dictionary;
 - `authKeys`, `authServer` and `authPortal`: see *Authorisation* below;
 - `public`: if true, then the group is listed on the landing page;
 - `displayName`: a human-friendly version of the group name;
@ -163,7 +173,7 @@ nobody will be able to join the group.  The following fields are allowed:
 - `unrestricted-tokens`: if true, then ordinary users (without the "op"
   privilege) are allowed to create tokens;
 - `allow-anonymous`: if true, then users may connect with an empty username;
- - `allow-subgroups`: if true, then subgroups of the form `group/subgroup`
+ - `auto-subgroups`: if true, then subgroups of the form `group/subgroup`
   are automatically created when first accessed;
 - `autolock`: if true, the group will start locked and become locked
   whenever there are no clients with operator privileges;
@ -202,33 +212,34 @@ even Unix passwords).
 ### Password authorisation

 When password authorisation is used, authorised usernames and password are
-defined directly in the group configuration file, in the `op`, `presenter`
-and `other` arrays.  Each member of the array is a dictionary, that may
-contain the fields `username` and `password`:
+defined directly in the group configuration file, in the `users` and
+`fallback-users` entries.  The `users` entry is a dictionary that maps
+user names to user descriptions; the `fallback-users` is a list of user
+descriptions that are used with usernames that don't appear in `users`.

- - if `username` is present, then the entry only matches clients that
-   specify this exact username; otherwise, any username matches;
- - if `password` is present, then the entry only matches clients that
-   specify this exact password; otherwise, any password matches.
+Every user description is a dictionary with fields `password` and
+`permissions`.  The `password` field may be a literal password string, or
+a dictionary describing a hashed password or a wildcard.  The
+`permissions` field should be one of `op`, `present` or `passive`.  (An
+array of Galene's internal permissions is also allowed, but this is not
+recommended, since internal permissions may vary from version to version).

-For example, the entry
+For fexample, the entry

-    {"username": "jch", "password": "1234"}
+    "users": {"jch": {"password": "1234", "permissions": "op"}}
    
-specifies username *jch* with password *1234*, while
+specifies that user "jch" may login as operator with password "1234", while

-    {"password": "1234"}
+    "fallback-users": [{"password": "1234", "permissions": "present"}]
    
-allows any username with password *1234*, and
+allows any username with password *1234*.  Finally,

-    {}
+    "fallback-users": [
+        {"password": {"type": "wildcard"}, "permissions": "present"}
+    ]
    
 allows any username with any password.

-By default, empty usernames are forbidden; set the `allow-anonymous`
-option to allow empty usernames.  By default, recording is forbidden;
-specify the `allow-recording` option to allow operators to record.
-

 ### Hashed passwords

@ -236,17 +247,20 @@ If you don't wish to store cleartext passwords on the server, you may
 generate hashed passwords with the `galene-password-generator` utility.  A
 user entry with a hashed password looks like this:

-    {
-        "username": "jch",
-        "password": {
-            "type": "pbkdf2",
-            "hash": "sha-256",
-            "key": "f591c35604e6aef572851d9c3543c812566b032b6dc083c81edd15cc24449913",
-            "salt": "92bff2ace56fe38f",
-            "iterations": 4096
+    "users": {
+        "jch": {
+            "password": {
+                "type": "pbkdf2",
+                "hash": "sha-256",
+                "key": "f591c35604e6aef572851d9c3543c812566b032b6dc083c81edd15cc24449913",
+                "salt": "92bff2ace56fe38f",
+                "iterations": 4096
+            },
+            "permissions": "op"
        }
    }

+
 ### Stateful tokens

 Stateful tokens allow to temporarily grant access to a user.  In order to
--- a/galene-password-generator/galene-password-generator.go
+++ b/galene-password-generator/galene-password-generator.go
@ -24,8 +24,11 @@ func main() {
 	var length int
 	var saltLen int
 	var username string
+	var permissions string
 	flag.StringVar(&username, "user", "",
 		"generate entry for given `username`")
+	flag.StringVar(&permissions, "permissions", "present",
+		"`permissions` for user entry")
 	flag.StringVar(&algorithm, "hash", "pbkdf2",
 		"hashing `algorithm`")
 	flag.IntVar(&iterations, "iterations", 4096,
@ -82,9 +85,14 @@ func main() {

 		e := json.NewEncoder(os.Stdout)
 		if username != "" {
-			creds := group.ClientPattern{
-				Username: username,
-				Password: &p,
+			perms, err := group.NewPermissions(permissions)
+			if err != nil {
+				log.Fatalf("NewPermissions: %v", err)
+			}
+			creds := make(map[string]group.UserDescription)
+			creds[username] = group.UserDescription{
+				Password:    p,
+				Permissions: perms,
 			}
 			err = e.Encode(creds)
 		} else {
--- a/group/client.go
+++ b/group/client.go
@ -27,7 +27,11 @@ type Password RawPassword
 func (p Password) Match(pw string) (bool, error) {
 	switch p.Type {
 	case "":
+		return false, errors.New("missing password")
+	case "plain":
 		return p.Key == pw, nil
+	case "wildcard":
+		return true, nil
 	case "pbkdf2":
 		key, err := hex.DecodeString(p.Key)
 		if err != nil {
@ -64,6 +68,7 @@ func (p *Password) UnmarshalJSON(b []byte) error {
 	err := json.Unmarshal(b, &k)
 	if err == nil {
 		*p = Password{
+			Type: "plain",
 			Key: k,
 		}
 		return nil
@ -77,7 +82,7 @@ func (p *Password) UnmarshalJSON(b []byte) error {
 }

 func (p Password) MarshalJSON() ([]byte, error) {
-	if p.Type == "" && p.Hash == "" && p.Salt == "" && p.Iterations == 0 {
+	if p.Type == "plain" && p.Hash == "" && p.Salt == "" && p.Iterations == 0 {
 		return json.Marshal(p.Key)
 	}
 	return json.Marshal(RawPassword(p))
--- a/group/client_test.go
+++ b/group/client_test.go
@ -7,8 +7,13 @@ import (
 	"testing"
 )

-var pw1 = Password{}
-var pw2 = Password{Key: "pass"}
+var pw1 = Password{
+	Type: "plain",
+}
+var pw2 = Password{
+	Type: "plain",
+	Key: "pass",
+}
 var pw3 = Password{
 	Type:       "pbkdf2",
 	Hash:       "sha-256",
@ -20,11 +25,15 @@ var pw4 = Password{
 	Type: "bcrypt",
 	Key: "$2a$10$afOr2f33onT/nDFFyT3mbOq5FMSw1wWXfyTXQTBMbKvZpBkoD3Qwu",
 }
-var pw5 = Password{
+var pw5 = Password{}
+var pw6 = Password{
 	Type: "bad",
 }

 func TestGood(t *testing.T) {
+	if match, err := pw1.Match(""); err != nil || !match {
+		t.Errorf("pw2 doesn't match (%v)", err)
+	}
 	if match, err := pw2.Match("pass"); err != nil || !match {
 		t.Errorf("pw2 doesn't match (%v)", err)
 	}
@ -37,9 +46,6 @@ func TestGood(t *testing.T) {
 }

 func TestBad(t *testing.T) {
-	if match, err := pw1.Match("bad"); err != nil || match {
-		t.Errorf("pw1 matches")
-	}
 	if match, err := pw2.Match("bad"); err != nil || match {
 		t.Errorf("pw2 matches")
 	}
@ -49,8 +55,14 @@ func TestBad(t *testing.T) {
 	if match, err := pw4.Match("bad"); err != nil || match {
 		t.Errorf("pw4 matches")
 	}
+	if match, err := pw5.Match(""); err == nil || match {
+		t.Errorf("pw5 matches")
+	}
 	if match, err := pw5.Match("bad"); err == nil || match {
-		t.Errorf("pw4 matches")
+		t.Errorf("pw5 matches")
+	}
+	if match, err := pw6.Match("bad"); err == nil || match {
+		t.Errorf("pw6 matches")
 	}
 }

@ -71,7 +83,7 @@ func TestJSON(t *testing.T) {
 		var pw2 Password
 		err = json.Unmarshal(j, &pw2)
 		if err != nil {
-			t.Fatalf("Unmarshal: %v", err)
+			t.Errorf("Unmarshal: %v", err)
 		} else if !reflect.DeepEqual(pw, pw2) {
 			t.Errorf("Expected %v, got %v", pw, pw2)
 		}
--- a/group/description.go
+++ b/group/description.go
@ -2,6 +2,8 @@ package group

 import (
 	"encoding/json"
+	"errors"
+	"log"
 	"os"
 	"path"
 	"path/filepath"
@ -9,6 +11,106 @@ import (
 	"time"
 )

+type Permissions struct {
+	// non-empty for a named permissions set
+	name string
+	// only used when unnamed
+	permissions []string
+}
+
+var permissionsMap = map[string][]string{
+	"op":      []string{"op", "present", "token"},
+	"present": []string{"present"},
+	"observe": []string{},
+	"admin":   []string{"admin"},
+}
+
+func NewPermissions(name string) (Permissions, error) {
+	_, ok := permissionsMap[name]
+	if !ok {
+		return Permissions{}, errors.New("unknown permission")
+	}
+	return Permissions{
+		name: name,
+	}, nil
+}
+
+func (p Permissions) Permissions(desc *Description) []string {
+	if p.name == "" {
+		return p.permissions
+	}
+
+	perms := permissionsMap[p.name]
+
+	op := false
+	present := false
+	token := false
+	record := false
+	for _, p := range perms {
+		switch p {
+		case "op":
+			op = true
+		case "present":
+			present = true
+		case "token":
+			token = true
+		case "record":
+			record = true
+		}
+	}
+
+	if desc != nil && desc.AllowRecording {
+		if op && !record {
+			// copy the slice
+			perms = append([]string{"record"}, perms...)
+		}
+	}
+
+	if desc != nil && desc.UnrestrictedTokens {
+		if present && !token {
+			perms = append([]string{"token"}, perms...)
+		}
+	}
+
+	return perms
+}
+
+func (p *Permissions) UnmarshalJSON(b []byte) error {
+	var a []string
+	err := json.Unmarshal(b, &a)
+	if err == nil {
+		*p = Permissions{
+			permissions: a,
+		}
+		return nil
+	}
+	var s string
+	err = json.Unmarshal(b, &s)
+	if err == nil {
+		_, ok := permissionsMap[s]
+		if !ok {
+			return errors.New("Unknown permission " + s)
+		}
+		*p = Permissions{
+			name: s,
+		}
+		return nil
+	}
+	return err
+}
+
+func (p Permissions) MarshalJSON() ([]byte, error) {
+	if p.name != "" {
+		return json.Marshal(p.name)
+	}
+	return json.Marshal(p.permissions)
+}
+
+type UserDescription struct {
+	Password    Password    `json:"password"`
+	Permissions Permissions `json:"permissions"`
+}
+
 // Description represents a group description together with some metadata
 // about the JSON file it was deserialised from.
 type Description struct {
@ -47,14 +149,11 @@ type Description struct {
 	MaxHistoryAge int `json:"max-history-age,omitempty"`

 	// Time after which joining is no longer allowed
-	Expires *time.Time `json:"expires"`
+	Expires *time.Time `json:"expires,omitempty"`

 	// Time before which joining is not allowed
 	NotBefore *time.Time `json:"not-before,omitempty"`

-	// Whether users are allowed to log in with an empty username.
-	AllowAnonymous bool `json:"allow-anonymous,omitempty"`
-
 	// Whether recording is allowed.
 	AllowRecording bool `json:"allow-recording,omitempty"`

@ -62,7 +161,7 @@ type Description struct {
 	UnrestrictedTokens bool `json:"unrestricted-tokens,omitempty"`

 	// Whether subgroups are created on the fly.
-	AllowSubgroups bool `json:"allow-subgroups,omitempty"`
+	AutoSubgroups bool `json:"auto-subgroups,omitempty"`

 	// Whether to lock the group when the last op logs out.
 	Autolock bool `json:"autolock,omitempty"`
@ -70,14 +169,11 @@ type Description struct {
 	// Whether to kick all users when the last op logs out.
 	Autokick bool `json:"autokick,omitempty"`

-	// A list of logins for ops.
-	Op []ClientPattern `json:"op,omitempty"`
+	// Users allowed to login
+	Users map[string]UserDescription `json:"users,omitempty"`

-	// A list of logins for presenters.
-	Presenter []ClientPattern `json:"presenter,omitempty"`
-
-	// A list of logins for non-presenting users.
-	Other []ClientPattern `json:"other,omitempty"`
+	// Credentials for users with arbitrary username
+	FallbackUsers []UserDescription `json:"fallback-users,omitempty"`

 	// The (public) keys used for token authentication.
 	AuthKeys []map[string]interface{} `json:"authKeys,omitempty"`
@ -91,6 +187,13 @@ type Description struct {
 	// Codec preferences.  If empty, a suitable default is chosen in
 	// the APIFromNames function.
 	Codecs []string `json:"codecs,omitempty"`
+
+	// Obsolete fields
+	Op             []ClientPattern `json:"op,omitempty"`
+	Presenter      []ClientPattern `json:"presenter,omitempty"`
+	Other          []ClientPattern `json:"other,omitempty"`
+	AllowSubgroups bool            `json:"allow-subgroups,omitempty"`
+	AllowAnonymous bool            `json:"allow-anonymous,omitempty"`
 }

 const DefaultMaxHistoryAge = 4 * time.Hour
@ -181,7 +284,7 @@ func readDescription(name string) (*Description, error) {
 		return nil, err
 	}
 	if isParent {
-		if !desc.AllowSubgroups {
+		if !desc.AutoSubgroups {
 			return nil, os.ErrNotExist
 		}
 		desc.Public = false
@ -192,5 +295,78 @@ func readDescription(name string) (*Description, error) {
 	desc.fileSize = fi.Size()
 	desc.modTime = fi.ModTime()

+	err = upgradeDescription(&desc)
+	if err != nil {
+		return nil, err
+	}
+
 	return &desc, nil
 }
+
+func upgradeDescription(desc *Description) error {
+	if desc.AllowAnonymous {
+		log.Printf(
+			"%v: field allow-anonymous is obsolete, ignored",
+			desc.FileName,
+		)
+		desc.AllowAnonymous = false
+	}
+
+	if desc.AllowSubgroups {
+		desc.AutoSubgroups = true
+		desc.AllowSubgroups = false
+	}
+
+	upgradePassword := func(pw *Password) Password {
+		if pw == nil {
+			return Password{
+				Type: "wildcard",
+			}
+		}
+		return *pw
+	}
+
+	upgradeUser := func(u ClientPattern, p string) UserDescription {
+		return UserDescription{
+			Password: upgradePassword(u.Password),
+			Permissions: Permissions{
+				name: p,
+			},
+		}
+	}
+
+	upgradeUsers := func(ps []ClientPattern, p string) {
+		if desc.Users == nil {
+			desc.Users = make(map[string]UserDescription)
+		}
+		for _, u := range ps {
+			if u.Username == "" {
+				desc.FallbackUsers = append(desc.FallbackUsers,
+					upgradeUser(u, p))
+				continue
+			}
+			_, found := desc.Users[u.Username]
+			if found {
+				log.Printf("%v: duplicate user %v, ignored",
+					desc.FileName, u.Username)
+				continue
+			}
+			desc.Users[u.Username] = upgradeUser(u, p)
+		}
+	}
+
+	if desc.Op != nil {
+		upgradeUsers(desc.Op, "op")
+		desc.Op = nil
+	}
+	if desc.Presenter != nil {
+		upgradeUsers(desc.Presenter, "present")
+		desc.Presenter = nil
+	}
+	if desc.Other != nil {
+		upgradeUsers(desc.Other, "observe")
+		desc.Other = nil
+	}
+
+	return nil
+}
--- a/group/description_test.go
+++ b/group/description_test.go
@ -0,0 +1,97 @@
+package group
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+var descJSON = `
+{
+    "max-history-age": 10,
+    "allow-subgroups": true,
+    "users": {
+        "jch": {"password": "topsecret", "permissions": "op"},
+        "john": {"password": "secret", "permissions": "present"},
+        "james": {"password": "secret2", "permissions": "observe"},
+        "peter": {"password": "secret4"}
+    },
+    "fallback-users": [
+        {"permissions": "observe", "password": {"type":"wildcard"}}
+    ]
+}`
+
+func TestDescriptionJSON(t *testing.T) {
+	var d Description
+	err := json.Unmarshal([]byte(descJSON), &d)
+	if err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	dd, err := json.Marshal(d)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+
+	var ddd Description
+	err = json.Unmarshal([]byte(dd), &ddd)
+	if err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	if !reflect.DeepEqual(d, ddd) {
+		t.Errorf("Got %v, expected %v", ddd, d)
+	}
+}
+
+var obsoleteJSON = `
+{
+   "op": [{"username": "jch","password": "topsecret"}],
+   "max-history-age": 10,
+   "allow-subgroups": true,
+   "presenter": [
+       {"username": "john", "password": "secret"}
+   ],
+   "other": [
+       {"username": "james", "password": "secret2"},
+       {"username": "peter", "password": "secret4"},
+       {}
+   ]
+}`
+
+func TestUpgradeDescription(t *testing.T) {
+	var d1 Description
+	err := json.Unmarshal([]byte(descJSON), &d1)
+	if err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	var d2 Description
+	err = json.Unmarshal([]byte(obsoleteJSON), &d2)
+	if err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	err = upgradeDescription(&d2)
+	if err != nil {
+		t.Fatalf("upgradeDescription: %v", err)
+	}
+
+	if d2.Op != nil || d2.Presenter != nil || d2.Other != nil {
+		t.Errorf("legacy field is not nil")
+	}
+
+	if len(d1.Users) != len(d2.Users) {
+		t.Errorf("length not equal: %v != %v",
+			len(d1.Users), len(d2.Users))
+	}
+
+	for k, v1 := range d1.Users {
+		v2 := d2.Users[k]
+		if !reflect.DeepEqual(v1.Password, v2.Password) ||
+			!permissionsEqual(
+				v1.Permissions.Permissions(&d1),
+				v2.Permissions.Permissions(&d2),
+			) {
+			t.Errorf("%v not equal: %v != %v", k, v1, v2)
+		}
+	}
+}
--- a/group/group.go
+++ b/group/group.go
@ -847,43 +847,6 @@ func (g *Group) GetChatHistory() []ChatHistoryEntry {
 	return h
 }

-func matchClient(creds ClientCredentials, users []ClientPattern) (bool, bool) {
-	if creds.Username == nil {
-		return false, false
-	}
-	username := *creds.Username
-
-	matched := false
-	for _, u := range users {
-		if u.Username == username {
-			matched = true
-			if u.Password == nil {
-				return true, true
-			}
-			m, _ := u.Password.Match(creds.Password)
-			if m {
-				return true, true
-			}
-		}
-	}
-	if matched {
-		return true, false
-	}
-
-	for _, u := range users {
-		if u.Username == "" {
-			if u.Password == nil {
-				return true, true
-			}
-			m, _ := u.Password.Match(creds.Password)
-			if m {
-				return true, true
-			}
-		}
-	}
-	return false, false
-}
-
 // Configuration represents the contents of the data/config.json file.
 type Configuration struct {
 	// The modtime and size of the file.  These are used to detect
@ -891,10 +854,13 @@ type Configuration struct {
 	modTime  time.Time `json:"-"`
 	fileSize int64     `json:"-"`

-	PublicServer  bool            `json:"publicServer"`
-	CanonicalHost string          `json:"canonicalHost"`
-	ProxyURL      string          `json:"proxyURL"`
-	Admin         []ClientPattern `json:"admin"`
+	PublicServer  bool   `json:"publicServer"`
+	CanonicalHost string `json:"canonicalHost"`
+	ProxyURL      string `json:"proxyURL"`
+	Users         map[string]UserDescription
+
+	// obsolete fields
+	Admin []ClientPattern `json:"admin"`
 }

 func (conf Configuration) Zero() bool {
@ -945,52 +911,56 @@ func GetConfiguration() (*Configuration, error) {
 	if err != nil {
 		return nil, err
 	}
+	if conf.Admin != nil {
+		log.Printf("%v: field \"admin\" is obsolete, ignored", filename)
+		conf.Admin = nil
+	}
 	configuration.configuration = &conf
 	return configuration.configuration, nil
 }

 // called locked
-func (g *Group) getPasswordPermission(creds ClientCredentials) ([]string, error) {
+func (g *Group) getPasswordPermission(creds ClientCredentials) (Permissions, error) {
 	desc := g.description

 	if creds.Username == nil {
-		return nil, errors.New("username not provided")
+		return Permissions{}, errors.New("username not provided")
 	}
-	if !desc.AllowAnonymous && *creds.Username == "" {
-		return nil, ErrAnonymousNotAuthorised
-	}
-	if found, good := matchClient(creds, desc.Op); found {
-		if good {
-			p := []string{"op", "present", "token"}
-			if desc.AllowRecording {
-				p = append(p, "record")
+	if desc.Users != nil {
+		if c, found := desc.Users[*creds.Username]; found {
+			ok, err := c.Password.Match(creds.Password)
+			if err != nil {
+				return Permissions{}, err
 			}
-			return p, nil
-		}
-		return nil, &NotAuthorisedError{}
-	}
-	if found, good := matchClient(creds, desc.Presenter); found {
-		if good {
-			p := []string{"present"}
-			if desc.UnrestrictedTokens {
-				p = append(p, "token")
+			if ok {
+				return c.Permissions, nil
+			} else {
+				return Permissions{}, &NotAuthorisedError{}
 			}
-			return p, nil
 		}
-		return nil, &NotAuthorisedError{}
 	}
-	if found, good := matchClient(creds, desc.Other); found {
-		if good {
-			p := []string{}
-			if desc.UnrestrictedTokens {
-				p = append(p, "token")
-			}
-			return p, nil
-		}
-		return nil, &NotAuthorisedError{}

+	for _, c := range desc.FallbackUsers {
+		if c.Password.Type == "wildcard" {
+			continue
+		}
+		ok, _ := c.Password.Match(creds.Password)
+		if ok {
+			return c.Permissions, nil
+		}
 	}
-	return nil, &NotAuthorisedError{}
+
+	for _, c := range desc.FallbackUsers {
+		if c.Password.Type != "wildcard" {
+			continue
+		}
+		ok, _ := c.Password.Match(creds.Password)
+		if ok {
+			return c.Permissions, nil
+		}
+	}
+
+	return Permissions{}, &NotAuthorisedError{}
 }

 // Return true if there is a user entry with the given username.
@ -1003,21 +973,12 @@ func (g *Group) UserExists(username string) bool {

 // called locked
 func (g *Group) userExists(username string) bool {
-	if username == "" {
+	desc := g.description
+	if desc.Users == nil {
 		return false
 	}
-
-	desc := g.description
-	for _, ps := range [][]ClientPattern{
-		desc.Op, desc.Presenter, desc.Other,
-	} {
-		for _, p := range ps {
-			if p.Username == username {
-				return true
-			}
-		}
-	}
-	return false
+	_, found := desc.Users[username]
+	return found
 }

 // called locked
@ -1049,11 +1010,11 @@ func (g *Group) getPermission(creds ClientCredentials) (string, []string, error)
 		}
 	} else if creds.Username != nil {
 		username = *creds.Username
-		var err error
-		perms, err = g.getPasswordPermission(creds)
+		ps, err := g.getPasswordPermission(creds)
 		if err != nil {
 			return "", nil, err
 		}
+		perms = ps.Permissions(desc)
 	} else {
 		return "", nil, errors.New("neither username nor token provided")
 	}
--- a/group/group_test.go
+++ b/group/group_test.go
@ -4,9 +4,9 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"reflect"
 	"testing"
 	"time"
+	"sort"
 )

 func TestGroup(t *testing.T) {
@ -70,50 +70,35 @@ func TestChatHistory(t *testing.T) {
 	}
 }

-var descJSON = `
-{
-    "op": [{"username": "jch","password": "topsecret"}],
-    "max-history-age": 10,
-    "allow-subgroups": true,
-    "presenter": [
-        {"username": "john", "password": "secret"},
-        {"username": "john", "password": "secret2"}
-    ],
-    "other": [
-        {"username": "james", "password": "secret3"},
-        {"username": "peter", "password": "secret4"},
-        {}
-    ]
-
-}`
-
-func TestDescriptionJSON(t *testing.T) {
-	var d Description
-	err := json.Unmarshal([]byte(descJSON), &d)
-	if err != nil {
-		t.Fatalf("unmarshal: %v", err)
+func permissionsEqual(a, b []string) bool {
+	// nil case
+	if len(a) == 0 && len(b) == 0 {
+		return true
 	}
-
-	dd, err := json.Marshal(d)
-	if err != nil {
-		t.Fatalf("marshal: %v", err)
+	if len(a) != len(b) {
+		return false
 	}
-
-	var ddd Description
-	err = json.Unmarshal([]byte(dd), &ddd)
-	if err != nil {
-		t.Fatalf("unmarshal: %v", err)
-	}
-
-	if !reflect.DeepEqual(d, ddd) {
-		t.Errorf("Got %v, expected %v", ddd, d)
+	aa := append([]string(nil), a...)
+	sort.Slice(aa, func(i, j int) bool {
+		return aa[i] < aa[j]
+	})
+	bb := append([]string(nil), b...)
+	sort.Slice(bb, func(i, j int) bool {
+		return bb[i] < bb[j]
+	})
+	for i := range aa {
+		if aa[i] != bb[i] {
+			return false
+		}
 	}
+	return true
 }

 var jch = "jch"
 var john = "john"
 var james = "james"
 var paul = "paul"
+var peter = "peter"

 var badClients = []ClientCredentials{
 	{Username: &jch, Password: "foo"},
@ -136,17 +121,17 @@ var goodClients = []credPerm{
 		[]string{"present"},
 	},
 	{
-		ClientCredentials{Username: &john, Password: "secret2"},
-		[]string{"present"},
-	},
-	{
-		ClientCredentials{Username: &james, Password: "secret3"},
+		ClientCredentials{Username: &james, Password: "secret2"},
 		[]string{},
 	},
 	{
 		ClientCredentials{Username: &paul, Password: "secret3"},
 		[]string{},
 	},
+	{
+		ClientCredentials{Username: &peter, Password: "secret4"},
+		[]string{},
+	},
 }

 func TestPermissions(t *testing.T) {
@ -172,7 +157,7 @@ func TestPermissions(t *testing.T) {
 			if err != nil {
 				t.Errorf("GetPermission %v: %v", cp.c, err)
 			} else if u != *cp.c.Username ||
-				!reflect.DeepEqual(p, cp.p) {
+				!permissionsEqual(p, cp.p) {
 				t.Errorf("%v: got %v %v, expected %v",
 					cp.c, u, p, cp.p)
 			}
@ -181,6 +166,55 @@ func TestPermissions(t *testing.T) {

 }

+func TestExtraPermissions(t *testing.T) {
+	j := `
+{
+    "users": {
+        "jch": {"password": "topsecret", "permissions": "op"},
+        "john": {"password": "secret", "permissions": "present"},
+        "james": {"password": "secret2", "permissions": "observe"}
+    }
+}`
+
+	var d Description
+	err := json.Unmarshal([]byte(j), &d)
+	if err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+
+	doit := func(u string, p []string) {
+		pu := d.Users[u].Permissions.Permissions(&d)
+		if !permissionsEqual(pu, p) {
+			t.Errorf("%v: expected %v, got %v", u, p, pu)
+		}
+	}
+
+	doit("jch", []string{"op", "token", "present"})
+	doit("john", []string{"present"})
+	doit("james", []string{})
+
+	d.AllowRecording = true
+	d.UnrestrictedTokens = false
+
+	doit("jch", []string{"op", "record", "token", "present"})
+	doit("john", []string{"present"})
+	doit("james", []string{})
+
+	d.AllowRecording = false
+	d.UnrestrictedTokens = true
+
+	doit("jch", []string{"op", "token", "present"})
+	doit("john", []string{"token", "present"})
+	doit("james", []string{})
+
+	d.AllowRecording = true
+	d.UnrestrictedTokens = true
+
+	doit("jch", []string{"op", "record", "token", "present"})
+	doit("john", []string{"token", "present"})
+	doit("james", []string{})
+}
+
 func TestUsernameTaken(t *testing.T) {
 	var g Group
 	err := json.Unmarshal([]byte(descJSON), &g.description)
--- a/webserver/webserver.go
+++ b/webserver/webserver.go
@ -466,13 +466,24 @@ func adminMatch(username, password string) (bool, error) {
 		return false, err
 	}

-	for _, cred := range conf.Admin {
-		if cred.Username == "" || cred.Username == username {
-			if ok, _ := cred.Password.Match(password); ok {
+	u, found := conf.Users[username]
+	if found {
+		ok, err := u.Password.Match(password)
+		if err != nil {
+			return false, err
+		}
+		if !ok {
+			return false, nil
+		}
+		perms := u.Permissions.Permissions(nil)
+		for _, p := range perms {
+			if p == "admin" {
 				return true, nil
 			}
 		}
+		return false, nil
 	}
+
 	return false, nil
 }

--- a/webserver/webserver_test.go
+++ b/webserver/webserver_test.go
@ -8,8 +8,9 @@ import (
 	"path/filepath"
 	"testing"

-	"github.com/jech/galene/group"
 	"github.com/pion/webrtc/v3"
+
+	"github.com/jech/galene/group"
 )

 func TestParseGroupName(t *testing.T) {
@ -190,6 +191,54 @@ func TestFormatICEServer(t *testing.T) {
 	}
 }

+func TestMatchAdmin(t *testing.T) {
+	d := t.TempDir()
+	group.DataDirectory = d
+
+	filename := filepath.Join(d, "config.json")
+	f, err := os.Create(filename)
+	if err != nil {
+		t.Fatalf("Create %v: %v", filename, err)
+	}
+	f.Write([]byte(`{
+	    "users": {
+		"root": {"password": "pwd", "permissions": "admin"},
+		"notroot": {"password": "pwd"}
+	    }
+	}`))
+	f.Close()
+
+	ok, err := adminMatch("jch", "pwd")
+	if ok || err != nil {
+		t.Errorf("jch: %v %v", ok, err)
+	}
+
+	ok, err = adminMatch("root", "pwd")
+	if !ok || err != nil {
+		t.Errorf("root: %v %v", ok, err)
+	}
+
+	ok, err = adminMatch("root", "notpwd")
+	if ok || err != nil {
+		t.Errorf("root: %v %v", ok, err)
+	}
+
+	ok, err = adminMatch("root", "")
+	if ok || err != nil {
+		t.Errorf("root: %v %v", ok, err)
+	}
+
+	ok, err = adminMatch("notroot", "pwd")
+	if ok || err != nil {
+		t.Errorf("notroot: %v %v", ok, err)
+	}
+
+	ok, err = adminMatch("notroot", "notpwd")
+	if ok || err != nil {
+		t.Errorf("notroot: %v %v", ok, err)
+	}
+}
+
 func TestObfuscate(t *testing.T) {
 	id := newId()
 	obfuscated, err := obfuscate(id)