feat(OCM): Make it possible to have a spec compliant discovery

The current discovery document have non standard elements, which are
required for backwards compatibility with old Nextcloud versions.

There may however be deployments, that are up to date, and do not require
backwards compatibility but instead value spec compliance and adding two
new knobs to LocalOCMDiscoveryEvent can make that happen.

The new knobs are removeVersion which removes the non standard version
field from the discovery and sets the correct apiVersion instead.
Nextcloud prior to version 28 had an equality check for apiVersion and
the hard coded string `1.0-proposal1` which is not at all the version
that Nextcloud actually supports.

Along side this change a new function removePublicKey is also added. The
publicKey in the discovery document is no longer used with the RFC9421
style http-signatures, and only the old legacy signatures use that key,
since version 35 Nextcloud supports RFC9421 signatures, and the legacy
publicKey can now be removed from the discovery if you don't require
backwards compatibility with older Nextcloud versions.

Fixes: #52754

Signed-off-by: Micke Nordin <kano@sunet.se>

Author: mickenordin

lib/private/OCM/Model/OCMProvider.php

@@ -21,6 +21,8 @@
  */
 class OCMProvider implements IOCMProvider {
 	private bool $enabled = false;
+	private bool $removePublicKey = false;
+	private bool $removeVersion = false;
 	private string $apiVersion = '';
 	private string $inviteAcceptDialog = '';
 	private array $capabilities = [];
@@ -326,6 +328,22 @@ private function looksValid(): bool {
 		return ($this->getApiVersion() !== '' && $this->getEndPoint() !== '');
 	}
 
+	/**
+	 * @since 35.0.0
+	 */
+	#[\Override]
+	public function removePublicKey(): void {
+		$this->removePublicKey = true;
+	}
+
+	/**
+	 * @since 35.0.0
+	 */
+	#[\Override]
+	public function removeVersion(): void {
+		$this->removeVersion = true;
+	}
+
 	/**
 	 * @since 28.0.0
 	 */
@@ -346,6 +364,15 @@ public function jsonSerialize(): array {
 			'resourceTypes' => $resourceTypes
 		];
 
+		if ($this->removeVersion) {
+			$response['apiVersion'] = $this->getApiVersion();
+			unset($response['version']);
+		}
+
+		if ($this->removePublicKey) {
+			unset($response['publicKey']);
+		}
+
 		if ($this->capabilities !== []) {
 			$response['capabilities'] = $this->capabilities;
 		}

lib/public/OCM/Events/LocalOCMDiscoveryEvent.php

@@ -54,4 +54,34 @@ public function registerResourceType(string $name, array $shareTypes, array $pro
 			->setProtocols($protocols);
 		$this->provider->addResourceType($resourceType);
 	}
+
+	/**
+	 * Remove the non-standard publicKey field from OCM discovery
+	 *
+	 * @since 35.0.0
+	 */
+	public function removePublicKey(): void {
+		$this->provider->removePublicKey();
+	}
+
+	/**
+	 * Remove the non-standard version field from OCM discovery
+	 *
+	 * @since 35.0.0
+	 */
+	public function removeVersion(): void {
+		$this->provider->removeVersion();
+	}
+
+	/**
+	 * Set the apiVersion
+	 *
+	 * @param string $version
+	 *
+	 * @since 35.0.0
+	 */
+	public function setApiVersion(string $version): void {
+		$this->provider->setApiVersion($version);
+	}
+
 }

lib/public/OCM/IOCMProvider.php

@@ -57,6 +57,20 @@ public function setApiVersion(string $apiVersion): static;
 	 */
 	public function getApiVersion(): string;
 
+	/**
+	 * Remove the non-standard publicKey field from OCM discovery
+	 *
+	 * @since 35.0.0
+	 */
+	public function removePublicKey(): void;
+
+	/**
+	 * Remove the non-standard version field from OCM discovery
+	 *
+	 * @since 35.0.0
+	 */
+	public function removeVersion(): void;
+
 	/**
 	 * configure endpoint
 	 *
@@ -219,7 +233,7 @@ public function import(array $data): static;
 	/**
 	 * @return array{
 	 *     enabled: bool,
-	 *     apiVersion: '1.0-proposal1',
+	 *     apiVersion: string,
 	 *     endPoint: string,
 	 *     publicKey?: array{
 	 *         keyId: string,
@@ -230,7 +244,7 @@ public function import(array $data): static;
 	 *         shareTypes: list<string>,
 	 *         protocols: array<string, string>
 	 *     }>,
-	 *     version: string
+	 *     version?: string
 	 * }
 	 * @since 28.0.0
 	 */