Add wildcard access control

This commit is contained in:
Philipp Heckel 2022-01-31 11:44:58 -05:00
parent 631ade5430
commit c56814e7da
4 changed files with 56 additions and 24 deletions

View File

@ -1,6 +1,9 @@
package auth
import "errors"
import (
"errors"
"regexp"
)
// Auther is a generic interface to implement password-based authentication and authorization
type Auther interface {
@ -39,12 +42,12 @@ type Manager interface {
ChangeRole(username string, role Role) error
// AllowAccess adds or updates an entry in th access control list for a specific user. It controls
// read/write access to a topic.
AllowAccess(username string, topic string, read bool, write bool) error
// read/write access to a topic. The parameter topicPattern may include wildcards (*).
AllowAccess(username string, topicPattern string, read bool, write bool) error
// ResetAccess removes an access control list entry for a specific username/topic, or (if topic is
// empty) for an entire user.
ResetAccess(username string, topic string) error
// empty) for an entire user. The parameter topicPattern may include wildcards (*).
ResetAccess(username string, topicPattern string) error
// DefaultAccess returns the default read/write access if no access control entry matches
DefaultAccess() (read bool, write bool)
@ -89,11 +92,26 @@ const (
Everyone = "*"
)
var (
allowedUsernameRegex = regexp.MustCompile(`^[-_.@a-zA-Z0-9]+$`) // Does not include Everyone (*)
allowedTopicPatternRegex = regexp.MustCompile(`^[-_*A-Za-z0-9]{1,64}$`) // Adds '*' for wildcards!
)
// AllowedRole returns true if the given role can be used for new users
func AllowedRole(role Role) bool {
return role == RoleUser || role == RoleAdmin
}
// AllowedUsername returns true if the given username is valid
func AllowedUsername(username string) bool {
return allowedUsernameRegex.MatchString(username)
}
// AllowedTopicPattern returns true if the given topic pattern is valid; this includes the wildcard character (*)
func AllowedTopicPattern(username string) bool {
return allowedTopicPatternRegex.MatchString(username)
}
// Error constants used by the package
var (
ErrUnauthenticated = errors.New("unauthenticated")

View File

@ -4,7 +4,7 @@ import (
"database/sql"
_ "github.com/mattn/go-sqlite3" // SQLite driver
"golang.org/x/crypto/bcrypt"
"regexp"
"strings"
)
const (
@ -37,7 +37,7 @@ const (
selectTopicPermsQuery = `
SELECT read, write
FROM access
WHERE user IN ('*', ?) AND topic = ?
WHERE user IN ('*', ?) AND ? LIKE topic
ORDER BY user DESC
`
)
@ -69,10 +69,6 @@ type SQLiteAuth struct {
defaultWrite bool
}
var (
allowedUsernameRegex = regexp.MustCompile(`^[-_.@a-zA-Z0-9]+$`)
)
var _ Auther = (*SQLiteAuth)(nil)
var _ Manager = (*SQLiteAuth)(nil)
@ -161,7 +157,7 @@ func (a *SQLiteAuth) resolvePerms(read, write bool, perm Permission) error {
// AddUser adds a user with the given username, password and role. The password should be hashed
// before it is stored in a persistence layer.
func (a *SQLiteAuth) AddUser(username, password string, role Role) error {
if !allowedUsernameRegex.MatchString(username) || !AllowedRole(role) {
if !AllowedUsername(username) || !AllowedRole(role) {
return ErrInvalidArgument
}
hash, err := bcrypt.GenerateFromPassword([]byte(password), bcryptCost)
@ -177,7 +173,7 @@ func (a *SQLiteAuth) AddUser(username, password string, role Role) error {
// RemoveUser deletes the user with the given username. The function returns nil on success, even
// if the user did not exist in the first place.
func (a *SQLiteAuth) RemoveUser(username string) error {
if !allowedUsernameRegex.MatchString(username) || username == Everyone {
if !AllowedUsername(username) {
return ErrInvalidArgument
}
if _, err := a.db.Exec(deleteUserQuery, username); err != nil {
@ -284,7 +280,7 @@ func (a *SQLiteAuth) readGrants(username string) ([]Grant, error) {
return nil, err
}
grants = append(grants, Grant{
Topic: topic,
Topic: fromSQLWildcard(topic),
Read: read,
Write: write,
})
@ -307,7 +303,7 @@ func (a *SQLiteAuth) ChangePassword(username, password string) error {
// ChangeRole changes a user's role. When a role is changed from RoleUser to RoleAdmin,
// all existing access control entries (Grant) are removed, since they are no longer needed.
func (a *SQLiteAuth) ChangeRole(username string, role Role) error {
if !allowedUsernameRegex.MatchString(username) || !AllowedRole(role) {
if !AllowedUsername(username) || !AllowedRole(role) {
return ErrInvalidArgument
}
if _, err := a.db.Exec(updateUserRoleQuery, string(role), username); err != nil {
@ -322,25 +318,31 @@ func (a *SQLiteAuth) ChangeRole(username string, role Role) error {
}
// AllowAccess adds or updates an entry in th access control list for a specific user. It controls
// read/write access to a topic.
func (a *SQLiteAuth) AllowAccess(username string, topic string, read bool, write bool) error {
if _, err := a.db.Exec(upsertUserAccessQuery, username, topic, read, write); err != nil {
// read/write access to a topic. The parameter topicPattern may include wildcards (*).
func (a *SQLiteAuth) AllowAccess(username string, topicPattern string, read bool, write bool) error {
if (!AllowedUsername(username) && username != Everyone) || !AllowedTopicPattern(topicPattern) {
return ErrInvalidArgument
}
if _, err := a.db.Exec(upsertUserAccessQuery, username, toSQLWildcard(topicPattern), read, write); err != nil {
return err
}
return nil
}
// ResetAccess removes an access control list entry for a specific username/topic, or (if topic is
// empty) for an entire user.
func (a *SQLiteAuth) ResetAccess(username string, topic string) error {
if username == "" && topic == "" {
// empty) for an entire user. The parameter topicPattern may include wildcards (*).
func (a *SQLiteAuth) ResetAccess(username string, topicPattern string) error {
if (!AllowedUsername(username) && username != Everyone) || (!AllowedTopicPattern(topicPattern) && topicPattern != "") {
return ErrInvalidArgument
}
if username == "" && topicPattern == "" {
_, err := a.db.Exec(deleteAllAccessQuery, username)
return err
} else if topic == "" {
} else if topicPattern == "" {
_, err := a.db.Exec(deleteUserAccessQuery, username)
return err
}
_, err := a.db.Exec(deleteTopicAccessQuery, username, topic)
_, err := a.db.Exec(deleteTopicAccessQuery, username, toSQLWildcard(topicPattern))
return err
}
@ -348,3 +350,11 @@ func (a *SQLiteAuth) ResetAccess(username string, topic string) error {
func (a *SQLiteAuth) DefaultAccess() (read bool, write bool) {
return a.defaultRead, a.defaultWrite
}
func toSQLWildcard(s string) string {
return strings.ReplaceAll(s, "*", "%")
}
func fromSQLWildcard(s string) string {
return strings.ReplaceAll(s, "%", "*")
}

View File

@ -19,6 +19,7 @@ func TestSQLiteAuth_FullScenario_Default_DenyAll(t *testing.T) {
require.Nil(t, a.AllowAccess("ben", "everyonewrite", false, false)) // How unfair!
require.Nil(t, a.AllowAccess(auth.Everyone, "announcements", true, false))
require.Nil(t, a.AllowAccess(auth.Everyone, "everyonewrite", true, true))
require.Nil(t, a.AllowAccess(auth.Everyone, "up*", false, true)) // Everyone can write to /up*
phil, err := a.Authenticate("phil", "phil")
require.Nil(t, err)
@ -77,6 +78,8 @@ func TestSQLiteAuth_FullScenario_Default_DenyAll(t *testing.T) {
require.Nil(t, a.Authorize(nil, "announcements", auth.PermissionRead))
require.Nil(t, a.Authorize(nil, "everyonewrite", auth.PermissionRead))
require.Nil(t, a.Authorize(nil, "everyonewrite", auth.PermissionWrite))
require.Nil(t, a.Authorize(nil, "up1234", auth.PermissionWrite)) // Wildcard permission
require.Nil(t, a.Authorize(nil, "up5678", auth.PermissionWrite))
}
func TestSQLiteAuth_AddUser_Invalid(t *testing.T) {

View File

@ -63,6 +63,7 @@ type indexPage struct {
type handleFunc func(http.ResponseWriter, *http.Request, *visitor) error
var (
// If changed, don't forget to update Android App and auth_sqlite.go
topicRegex = regexp.MustCompile(`^[-_A-Za-z0-9]{1,64}$`) // No /!
topicPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}$`) // Regex must match JS & Android app!
jsonPathRegex = regexp.MustCompile(`^/[-_A-Za-z0-9]{1,64}(,[-_A-Za-z0-9]{1,64})*/json$`)
@ -75,7 +76,7 @@ var (
staticRegex = regexp.MustCompile(`^/static/.+`)
docsRegex = regexp.MustCompile(`^/docs(|/.*)$`)
fileRegex = regexp.MustCompile(`^/file/([-_A-Za-z0-9]{1,64})(?:\.[A-Za-z0-9]{1,16})?$`)
disallowedTopics = []string{"docs", "static", "file"}
disallowedTopics = []string{"docs", "static", "file"} // If updated, also update in Android app
attachURLRegex = regexp.MustCompile(`^https?://`)
templateFnMap = template.FuncMap{