Store keypairs as options keyed to user IDs. (#416)

includes/class-signature.php

@@ -4,7 +4,6 @@ namespace Activitypub;
 use WP_Error;
 use DateTime;
 use DateTimeZone;
-use Activitypub\Model\User;
 use Activitypub\Collection\Users;
 
 /**
@@ -23,22 +22,14 @@ class Signature {
 	 *
 	 * @return mixed The public key.
 	 */
-	public static function get_public_key( $user_id, $force = false ) {
+	public static function get_public_key_for( $user_id, $force = false ) {
 		if ( $force ) {
-			self::generate_key_pair( $user_id );
+			self::generate_key_pair_for( $user_id );
 		}
 
-		if ( User::APPLICATION_USER_ID === $user_id ) {
+		$key_pair = self::get_keypair_for( $user_id );
-			$key = \get_option( 'activitypub_magic_sig_public_key' );
-		} else {
-			$key = \get_user_meta( $user_id, 'magic_sig_public_key', true );
-		}
 
-		if ( ! $key ) {
+		return $key_pair['public_key'];
-			return self::get_public_key( $user_id, true );
-		}
-
-		return $key;
 	}
 
 	/**
@@ -49,22 +40,32 @@ class Signature {
 	 *
 	 * @return mixed The private key.
 	 */
-	public static function get_private_key( $user_id, $force = false ) {
+	public static function get_private_key_for( $user_id, $force = false ) {
 		if ( $force ) {
-			self::generate_key_pair( $user_id );
+			self::generate_key_pair_for( $user_id );
 		}
 
-		if ( User::APPLICATION_USER_ID === $user_id ) {
+		$key_pair = self::get_keypair_for( $user_id );
-			$key = \get_option( 'activitypub_magic_sig_private_key' );
+
-		} else {
+		return $key_pair['private_key'];
-			$key = \get_user_meta( $user_id, 'magic_sig_private_key', true );
+	}
+
+	/**
+	 * Return the key pair for a given user.
+	 *
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return array The key pair.
+	 */
+	public static function get_keypair_for( $user_id ) {
+		$option_key = self::get_signature_options_key_for( $user_id );
+		$key_pair = \get_option( $option_key );
+
+		if ( ! $key_pair ) {
+			$key_pair = self::generate_key_pair_for( $user_id );
 		}
 
-		if ( ! $key ) {
+		return $key_pair;
-			return self::get_private_key( $user_id, true );
-		}
-
-		return $key;
 	}
 
 	/**
@@ -72,9 +73,18 @@ class Signature {
 	 *
 	 * @param int $user_id The WordPress User ID.
 	 *
-	 * @return void
+	 * @return array The key pair.
 	 */
-	public static function generate_key_pair() {
+	protected static function generate_key_pair_for( $user_id ) {
+		$option_key = self::get_signature_options_key_for( $user_id );
+		$key_pair = self::check_legacy_key_pair_for( $user_id );
+
+		if ( $key_pair ) {
+			\add_option( $option_key, $key_pair );
+
+			return $key_pair;
+		}
+
 		$config = array(
 			'digest_alg' => 'sha512',
 			'private_key_bits' => 2048,
@@ -88,10 +98,76 @@ class Signature {
 
 		$detail = \openssl_pkey_get_details( $key );
 
-		return array(
+		// check if keys are valid
+		if (
+			empty( $priv_key ) || ! is_string( $priv_key ) ||
+			! isset( $detail['key'] ) || ! is_string( $detail['key'] )
+		) {
+			return array(
+				'private_key' => null,
+				'public_key'  => null,
+			);
+		}
+
+		$key_pair = array(
 			'private_key' => $priv_key,
 			'public_key'  => $detail['key'],
 		);
+
+		// persist keys
+		\add_option( $option_key, $key_pair );
+
+		return $key_pair;
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @param [type] $user_id
+	 * @return void
+	 */
+	protected static function get_signature_options_key_for( $user_id ) {
+		$id = $user_id;
+
+		if ( $user_id > 0 ) {
+			$user = \get_userdata( $user_id );
+			$id = $user->user_login;
+		}
+
+		return 'activitypub_keypair_for_' . $id;
+	}
+
+	/**
+	 * Check if there is a legacy key pair
+	 *
+	 * @param int $user_id The WordPress User ID.
+	 *
+	 * @return array|bool The key pair or false.
+	 */
+	protected static function check_legacy_key_pair_for( $user_id ) {
+		switch ( $user_id ) {
+			case 0:
+				$public_key = \get_option( 'activitypub_blog_user_public_key' );
+				$private_key = \get_option( 'activitypub_blog_user_private_key' );
+				break;
+			case -1:
+				$public_key = \get_option( 'activitypub_application_user_public_key' );
+				$private_key = \get_option( 'activitypub_application_user_private_key' );
+				break;
+			default:
+				$public_key = \get_user_meta( $user_id, 'magic_sig_public_key', true );
+				$private_key = \get_user_meta( $user_id, 'magic_sig_private_key', true );
+				break;
+		}
+
+		if ( ! empty( $public_key ) && is_string( $public_key ) && ! empty( $private_key ) && is_string( $private_key ) ) {
+			return array(
+				'private_key' => $private_key,
+				'public_key'  => $public_key,
+			);
+		}
+
+		return false;
 	}
 
 	/**
@@ -107,7 +183,7 @@ class Signature {
 	 */
 	public static function generate_signature( $user_id, $http_method, $url, $date, $digest = null ) {
 		$user = Users::get_by_id( $user_id );
-		$key  = $user->get__private_key();
+		$key  = self::get_private_key_for( $user->get__id() );
 
 		$url_parts = \wp_parse_url( $url );
 
@@ -136,7 +212,6 @@ class Signature {
 		\openssl_sign( $signed_string, $signature, $key, \OPENSSL_ALGO_SHA256 );
 		$signature = \base64_encode( $signature ); // phpcs:ignore
 
-		$user   = Users::get_by_id( $user_id );
 		$key_id = $user->get_url() . '#main-key';
 
 		if ( ! empty( $digest ) ) {

includes/model/class-application-user.php

@@ -46,46 +46,6 @@ class Application_User extends Blog_User {
 		return $this::get_name();
 	}
 
-	public function get__public_key() {
-		$key = \get_option( 'activitypub_application_user_public_key' );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		$key = \get_option( 'activitypub_application_user_public_key' );
-
-		return $key;
-	}
-
-	/**
-	 * @param int $user_id
-	 *
-	 * @return mixed
-	 */
-	public function get__private_key() {
-		$key = \get_option( 'activitypub_application_user_private_key' );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		return \get_option( 'activitypub_application_user_private_key' );
-	}
-
-	private function generate_key_pair() {
-		$key_pair = Signature::generate_key_pair();
-
-		if ( ! is_wp_error( $key_pair ) ) {
-			\update_option( 'activitypub_application_user_public_key', $key_pair['public_key'] );
-			\update_option( 'activitypub_application_user_private_key', $key_pair['private_key'] );
-		}
-	}
-
 	public function get_followers() {
 		return null;
 	}

includes/model/class-blog-user.php

@@ -187,48 +187,6 @@ class Blog_User extends User {
 		return \gmdate( 'Y-m-d\TH:i:s\Z', $time );
 	}
 
-	public function get__public_key() {
-		$key = \get_option( 'activitypub_blog_user_public_key' );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		$key = \get_option( 'activitypub_blog_user_public_key' );
-
-		return $key;
-	}
-
-	/**
-	 * Get the User-Private-Key.
-	 *
-	 * @param int $user_id
-	 *
-	 * @return mixed
-	 */
-	public function get__private_key() {
-		$key = \get_option( 'activitypub_blog_user_private_key' );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		return \get_option( 'activitypub_blog_user_private_key' );
-	}
-
-	private function generate_key_pair() {
-		$key_pair = Signature::generate_key_pair();
-
-		if ( ! is_wp_error( $key_pair ) ) {
-			\update_option( 'activitypub_blog_user_public_key', $key_pair['public_key'] );
-			\update_option( 'activitypub_blog_user_private_key', $key_pair['private_key'] );
-		}
-	}
-
 	public function get_attachment() {
 		return array();
 	}

includes/model/class-user.php

@@ -159,53 +159,10 @@ class User extends Actor {
 		return array(
 			'id'       => $this->get_id() . '#main-key',
 			'owner'    => $this->get_id(),
-			'publicKeyPem' => $this->get__public_key(),
+			'publicKeyPem' => Signature::get_public_key_for( $this->get__id() ),
 		);
 	}
 
-	/**
-	 * @param int $this->get__id()
-	 *
-	 * @return mixed
-	 */
-	public function get__public_key() {
-		$key = \get_user_meta( $this->get__id(), 'magic_sig_public_key', true );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		return \get_user_meta( $this->get__id(), 'magic_sig_public_key', true );
-	}
-
-	/**
-	 * @param int $this->get__id()
-	 *
-	 * @return mixed
-	 */
-	public function get__private_key() {
-		$key = \get_user_meta( $this->get__id(), 'magic_sig_private_key', true );
-
-		if ( $key ) {
-			return $key;
-		}
-
-		$this->generate_key_pair();
-
-		return \get_user_meta( $this->get__id(), 'magic_sig_private_key', true );
-	}
-
-	private function generate_key_pair() {
-		$key_pair = Signature::generate_key_pair();
-
-		if ( ! is_wp_error( $key_pair ) ) {
-			\update_user_meta( $this->get__id(), 'magic_sig_public_key', $key_pair['public_key'], true );
-			\update_user_meta( $this->get__id(), 'magic_sig_private_key', $key_pair['private_key'], true );
-		}
-	}
-
 	/**
 	 * Returns the Inbox-API-Endpoint.
 	 *

tests/test-class-activitypub-rest-post-signature-verification.php

@@ -45,7 +45,7 @@ class Test_Activitypub_Signature_Verification extends WP_UnitTestCase {
 
 		$user = Activitypub\Collection\Users::get_by_id( 1 );
 
-		$public_key = $user->get__public_key();
+		$public_key = Activitypub\Signature::get_public_key_for( $user->get__id() );
 
 		// signature_verification
 		$verified = \openssl_verify( $signed_data, $signature_block['signature'], $public_key, 'rsa-sha256' ) > 0;
@@ -57,7 +57,7 @@ class Test_Activitypub_Signature_Verification extends WP_UnitTestCase {
 			'pre_get_remote_metadata_by_actor',
 			function( $json, $actor ) {
 				$user = Activitypub\Collection\Users::get_by_id( 1 );
-				$public_key = $user->get__public_key();
+				$public_key = Activitypub\Signature::get_public_key_for( $user->get__id() );
 				// return ActivityPub Profile with signature
 				return array(
 					'id' => $actor,

tests/test-class-activitypub-signature.php

@@ -0,0 +1,110 @@
+<?php
+
+class Test_Activitypub_Signature extends WP_UnitTestCase {
+	public function test_signature_creation() {
+		$user = Activitypub\Collection\Users::get_by_id( 1 );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+		$public_key = Activitypub\Signature::get_public_key_for( $user->get__id() );
+		$private_key = Activitypub\Signature::get_private_key_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+	}
+
+	public function test_signature_legacy() {
+		// check user
+		$user = Activitypub\Collection\Users::get_by_id( 1 );
+
+		$public_key = 'public key ' . $user->get__id();
+		$private_key = 'private key ' . $user->get__id();
+
+		update_user_meta( $user->get__id(), 'magic_sig_public_key', $public_key );
+		update_user_meta( $user->get__id(), 'magic_sig_private_key', $private_key );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+
+		// check application user
+		$user = Activitypub\Collection\Users::get_by_id( -1 );
+
+		$public_key = 'public key ' . $user->get__id();
+		$private_key = 'private key ' . $user->get__id();
+
+		add_option( 'activitypub_application_user_public_key', $public_key );
+		add_option( 'activitypub_application_user_private_key', $private_key );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+
+		// check blog user
+		\define( 'ACTIVITYPUB_DISABLE_BLOG_USER', false );
+		$user = Activitypub\Collection\Users::get_by_id( 0 );
+
+		$public_key = 'public key ' . $user->get__id();
+		$private_key = 'private key ' . $user->get__id();
+
+		add_option( 'activitypub_blog_user_public_key', $public_key );
+		add_option( 'activitypub_blog_user_private_key', $private_key );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+	}
+
+	public function test_signature_consistancy() {
+		// check user
+		$user = Activitypub\Collection\Users::get_by_id( 1 );
+
+		$public_key = 'public key ' . $user->get__id();
+		$private_key = 'private key ' . $user->get__id();
+
+		update_user_meta( $user->get__id(), 'magic_sig_public_key', $public_key );
+		update_user_meta( $user->get__id(), 'magic_sig_private_key', $private_key );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+
+		update_user_meta( $user->get__id(), 'magic_sig_public_key', $public_key . '-update' );
+		update_user_meta( $user->get__id(), 'magic_sig_private_key', $private_key . '-update' );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+	}
+
+	public function test_signature_consistancy2() {
+		$user = Activitypub\Collection\Users::get_by_id( 1 );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+		$public_key = Activitypub\Signature::get_public_key_for( $user->get__id() );
+		$private_key = Activitypub\Signature::get_private_key_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+
+		update_user_meta( $user->get__id(), 'magic_sig_public_key', 'test' );
+		update_user_meta( $user->get__id(), 'magic_sig_private_key', 'test' );
+
+		$key_pair = Activitypub\Signature::get_keypair_for( $user->get__id() );
+
+		$this->assertNotEmpty( $key_pair );
+		$this->assertEquals( $key_pair['public_key'], $public_key );
+		$this->assertEquals( $key_pair['private_key'], $private_key );
+	}
+}