Add workerSrc to CSP

Fixes #11035

Since the child-src directive is deprecated (we should kill it at some
point) we need to have the proper worker-src available

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

lib/private/Security/CSP/ContentSecurityPolicy.php

@@ -213,4 +213,12 @@ class ContentSecurityPolicy extends \OCP\AppFramework\Http\ContentSecurityPolicy
 		$this->allowedFrameAncestors = $allowedFrameAncestors;
 	}
 
+	public function getAllowedWorkerSrcDomains(): array {
+		return $this->allowedWorkerSrcDomains;
+	}
+
+	public function setAllowedWorkerSrcDomains(array $allowedWorkerSrcDomains) {
+		$this->allowedWorkerSrcDomains = $allowedWorkerSrcDomains;
+	}
+
 }

lib/public/AppFramework/Http/ContentSecurityPolicy.php

@@ -91,4 +91,7 @@ class ContentSecurityPolicy extends EmptyContentSecurityPolicy {
 
 	/** @var array Domains which can embed this Nextcloud instance */
 	protected $allowedFrameAncestors = [];
+
+	/** @var array Domains from which web-workers can be loaded */
+	protected $allowedWorkerSrcDomains = [];
 }

lib/public/AppFramework/Http/EmptyContentSecurityPolicy.php

@@ -73,6 +73,8 @@ class EmptyContentSecurityPolicy {
 	protected $allowedChildSrcDomains = null;
 	/** @var array Domains which can embed this Nextcloud instance */
 	protected $allowedFrameAncestors = null;
+	/** @var array Domains from which web-workers can be loaded */
+	protected $allowedWorkerSrcDomains = null;
 
 	/**
 	 * Whether inline JavaScript snippets are allowed or forbidden
@@ -355,6 +357,30 @@ class EmptyContentSecurityPolicy {
 		return $this;
 	}
 
+	/**
+	 * Domain from which workers can be loaded
+	 *
+	 * @param string $domain
+	 * @return $this
+	 * @since 15.0.0
+	 */
+	public function addAllowedWorkerSrcDomain(string $domain) {
+		$this->allowedWorkerSrcDomains[] = $domain;
+		return $this;
+	}
+
+	/**
+	 * Remove domain from which workers can be loaded
+	 *
+	 * @param string $domain
+	 * @return $this
+	 * @since 15.0.0
+	 */
+	public function disallowWorkerSrcDomain(string $domain) {
+		$this->allowedWorkerSrcDomains = array_diff($this->allowedWorkerSrcDomains, [$domain]);
+		return $this;
+	}
+
 	/**
 	 * Get the generated Content-Security-Policy as a string
 	 * @return string
@@ -439,6 +465,11 @@ class EmptyContentSecurityPolicy {
 			$policy .= ';';
 		}
 
+		if (!empty($this->allowedWorkerSrcDomains)) {
+			$policy .= 'worker-src ' . implode(' ', $this->allowedWorkerSrcDomains);
+			$policy .= ';';
+		}
+
 		return rtrim($policy, ';');
 	}
 }