diff --git a/editor/include/editing.inc.php b/editor/include/editing.inc.php
index b3eccaab..521f29c4 100644
--- a/editor/include/editing.inc.php
+++ b/editor/include/editing.inc.php
@@ -19,7 +19,7 @@ function email_header($header) {
 * @return bool
 */
 function send_mail($email, $subject, $message, $from = "", $files = array()) {
-	$eol = (DIRECTORY_SEPARATOR == "/" ? "\n" : "\r\n"); // PHP_EOL available since PHP 5.0.2
+	$eol = PHP_EOL;
 	$message = str_replace("\n", $eol, wordwrap(str_replace("\r", "", "$message\n")));
 	$boundary = uniqid("boundary");
 	$attachments = "";
diff --git a/plugins/drivers/clickhouse.php b/plugins/drivers/clickhouse.php
index 7ec86fdc..02ed758e 100644
--- a/plugins/drivers/clickhouse.php
+++ b/plugins/drivers/clickhouse.php
@@ -15,7 +15,7 @@ if (isset($_GET["clickhouse"])) {
 				'method' => 'POST',
 				'content' => $this->isQuerySelectLike($query) ? "$query FORMAT JSONCompact" : $query,
 				'header' => 'Content-type: application/x-www-form-urlencoded',
-				'ignore_errors' => 1, // available since PHP 5.2.10
+				'ignore_errors' => 1,
 				'follow_location' => 0,
 				'max_redirects' => 0,
 			))));
diff --git a/plugins/drivers/elastic5.php b/plugins/drivers/elastic5.php
index f3c69130..b0ec3226 100644
--- a/plugins/drivers/elastic5.php
+++ b/plugins/drivers/elastic5.php
@@ -21,7 +21,7 @@ if (isset($_GET["elastic5"])) {
 					'method' => $method,
 					'content' => $content !== null ? json_encode($content) : $content,
 					'header' => $content !== null ? 'Content-Type: application/json' : array(),
-					'ignore_errors' => 1, // available since PHP 5.2.10
+					'ignore_errors' => 1,
 					'follow_location' => 0,
 					'max_redirects' => 0,
 				))));
diff --git a/plugins/drivers/simpledb.php b/plugins/drivers/simpledb.php
index 02d3d4f0..a028bf33 100644
--- a/plugins/drivers/simpledb.php
+++ b/plugins/drivers/simpledb.php
@@ -391,22 +391,6 @@ if (isset($_GET["simpledb"])) {
 	function last_id() {
 	}
 
-	function hmac($algo, $data, $key, $raw_output = false) {
-		// can use hash_hmac() since PHP 5.1.2
-		$blocksize = 64;
-		if (strlen($key) > $blocksize) {
-			$key = pack("H*", $algo($key));
-		}
-		$key = str_pad($key, $blocksize, "\0");
-		$k_ipad = $key ^ str_repeat("\x36", $blocksize);
-		$k_opad = $key ^ str_repeat("\x5C", $blocksize);
-		$return = $algo($k_opad . pack("H*", $algo($k_ipad . $data)));
-		if ($raw_output) {
-			$return = pack("H*", $return);
-		}
-		return $return;
-	}
-
 	function sdb_request($action, $params = array()) {
 		$adminer = adminer();
 		$connection = connection();
@@ -422,11 +406,11 @@ if (isset($_GET["simpledb"])) {
 			$query .= '&' . rawurlencode($key) . '=' . rawurlencode($val);
 		}
 		$query = str_replace('%7E', '~', substr($query, 1));
-		$query .= "&Signature=" . urlencode(base64_encode(hmac('sha1', "POST\n" . preg_replace('~^https?://~', '', $host) . "\n/\n$query", $secret, true)));
+		$query .= "&Signature=" . urlencode(base64_encode(hash_hmac('sha1', "POST\n" . preg_replace('~^https?://~', '', $host) . "\n/\n$query", $secret, true)));
 		$file = @file_get_contents((preg_match('~^https?://~', $host) ? $host : "http://$host"), false, stream_context_create(array('http' => array(
 			'method' => 'POST', // may not fit in URL with GET
 			'content' => $query,
-			'ignore_errors' => 1, // available since PHP 5.2.10
+			'ignore_errors' => 1,
 			'follow_location' => 0,
 			'max_redirects' => 0,
 		))));