[PATCH] Hash IP for API rate limit
The hash uses the start of a fixed window as an HMAC key. Therefore the windows stored in the DB also use this so that there can only be one active window for each IP. Signed-off-by: Florian Pritz <bluewind@xinu.at> --- schema/aur-schema.sql | 2 +- upgrading/4.7.0.txt | 2 +- web/lib/aurjson.class.php | 12 +++++++----- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/schema/aur-schema.sql b/schema/aur-schema.sql index 79de3f2..45f8993 100644 --- a/schema/aur-schema.sql +++ b/schema/aur-schema.sql @@ -403,7 +403,7 @@ CREATE TABLE AcceptedTerms ( -- Rate limits for API -- CREATE TABLE `ApiRateLimit` ( - IP VARCHAR(45) NOT NULL, + IP VARCHAR(255) NOT NULL, Requests INT(11) NOT NULL, WindowStart BIGINT(20) NOT NULL, PRIMARY KEY (`ip`) diff --git a/upgrading/4.7.0.txt b/upgrading/4.7.0.txt index 820e454..fcdbb4d 100644 --- a/upgrading/4.7.0.txt +++ b/upgrading/4.7.0.txt @@ -2,7 +2,7 @@ --- CREATE TABLE `ApiRateLimit` ( - IP VARCHAR(45) NOT NULL, + IP VARCHAR(255) NOT NULL, Requests INT(11) NOT NULL, WindowStart BIGINT(20) NOT NULL, PRIMARY KEY (`ip`) diff --git a/web/lib/aurjson.class.php b/web/lib/aurjson.class.php index c51e9c2..168c6b7 100644 --- a/web/lib/aurjson.class.php +++ b/web/lib/aurjson.class.php @@ -153,6 +153,9 @@ private function check_ratelimit($ip) { } $window_length = config_get("ratelimit", "window_length"); + $hmac_key = floor(time() / ($window_length)); + $ip = hash_hmac("sha256", $ip, $hmac_key); + $this->update_ratelimit($ip); $stmt = $this->dbh->prepare(" SELECT Requests FROM ApiRateLimit @@ -181,14 +184,13 @@ private function check_ratelimit($ip) { private function update_ratelimit($ip) { $window_length = config_get("ratelimit", "window_length"); $db_backend = config_get("database", "backend"); - $time = time(); + $window_start = floor(time() / ($window_length)); // Clean up old windows - $deletion_time = $time - $window_length; $stmt = $this->dbh->prepare(" DELETE FROM ApiRateLimit WHERE WindowStart < :time"); - $stmt->bindParam(":time", $deletion_time); + $stmt->bindParam(":time", $window_start); $stmt->execute(); if ($db_backend == "mysql") { @@ -198,7 +200,7 @@ private function update_ratelimit($ip) { VALUES (:ip, 1, :window_start) ON DUPLICATE KEY UPDATE Requests=Requests+1"); $stmt->bindParam(":ip", $ip); - $stmt->bindParam(":window_start", $time); + $stmt->bindParam(":window_start", $window_start); $stmt->execute(); } elseif ($db_backend == "sqlite") { $stmt = $this->dbh->prepare(" @@ -206,7 +208,7 @@ private function update_ratelimit($ip) { (IP, Requests, WindowStart) VALUES (:ip, 0, :window_start);"); $stmt->bindParam(":ip", $ip); - $stmt->bindParam(":window_start", $time); + $stmt->bindParam(":window_start", $window_start); $stmt->execute(); $stmt = $this->dbh->prepare(" -- 2.17.0
participants (1)
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Florian Pritz