Merge pull request #11334 from annando/guid-style

Use a nicer GUID style format

src/Model/Item.php

@@ -1773,7 +1773,10 @@ class Item
 	}
 
 	/**
-	 * Creates an unique guid out of a given uri
+	 * Creates an unique guid out of a given uri.
+	 * This function is used for messages outside the fediverse (Connector posts, feeds, Mails, ...)
+	 * Posts that are created on this system are using System::createUUID.
+	 * Received ActivityPub posts are using Processor::getGUIDByURL.
 	 *
 	 * @param string $uri uri of an item entry
 	 * @param string $host hostname for the GUID prefix
@@ -1785,19 +1788,14 @@ class Item
 		// We have to avoid that different routines could accidentally create the same value
 		$parsed = parse_url($uri);
 
-		// We use a hash of the hostname as prefix for the guid
-		$guid_prefix = hash("crc32", $host);
-
 		// Remove the scheme to make sure that "https" and "http" doesn't make a difference
 		unset($parsed["scheme"]);
 
 		// Glue it together to be able to make a hash from it
 		$host_id = implode("/", $parsed);
 
-		// We could use any hash algorithm since it isn't a security issue
-		$host_hash = hash("ripemd128", $host_id);
-
-		return $guid_prefix.$host_hash;
+		// Use a mixture of several hashes to provide some GUID like experience
+		return hash("crc32", $host) . '-'. hash('joaat', $host_id) . '-'. hash('fnv164', $host_id);
 	}
 
 	/**

src/Protocol/ActivityPub/Processor.php

@@ -553,7 +553,7 @@ class Processor
 	}
 
 	/**
-	 * Generate a GUID out of an URL
+	 * Generate a GUID out of an URL of an ActivityPub post.
 	 *
 	 * @param string $url message URL
 	 * @return string with GUID