ext/standard: Make php_escape_shell_cmd() take a zend_string* instead of char*

This saves on an expensive strlen() computation

Author: Girgias

UPGRADING.INTERNALS

@@ -246,6 +246,9 @@ PHP 8.4 INTERNALS UPGRADE NOTES
  g. ext/standard
    - Added the php_base64_encode_ex() API with flag parameters, value can be
      PHP_BASE64_NO_PADDING to encode without the padding character '='.
+   - The php_escape_shell_cmd() now takes a zend_string* instead of a char*
+     Moreover, providing it with a binary safe string is the responsibility of
+     the caller now.
 
 ========================
 4. OpCode changes

ext/mbstring/mbstring.c

@@ -4654,9 +4654,9 @@ PHP_FUNCTION(mb_send_mail)
 
 	zend_string *force_extra_parameters = zend_ini_str_ex("mail.force_extra_parameters", strlen("mail.force_extra_parameters"), false, NULL);
 	if (force_extra_parameters) {
-		extra_cmd = php_escape_shell_cmd(ZSTR_VAL(force_extra_parameters));
+		extra_cmd = php_escape_shell_cmd(force_extra_parameters);
 	} else if (extra_cmd) {
-		extra_cmd = php_escape_shell_cmd(ZSTR_VAL(extra_cmd));
+		extra_cmd = php_escape_shell_cmd(extra_cmd);
 	}
 
 	RETVAL_BOOL(php_mail(to_r, ZSTR_VAL(subject), message, ZSTR_VAL(str_headers), extra_cmd ? ZSTR_VAL(extra_cmd) : NULL));

ext/standard/exec.c

@@ -279,16 +279,20 @@ PHP_FUNCTION(passthru)
 
    *NOT* safe for binary strings
 */
-PHPAPI zend_string *php_escape_shell_cmd(const char *str)
+PHPAPI zend_string *php_escape_shell_cmd(const zend_string *unescaped_cmd)
 {
 	size_t x, y;
-	size_t l = strlen(str);
-	uint64_t estimate = (2 * (uint64_t)l) + 1;
 	zend_string *cmd;
 #ifndef PHP_WIN32
 	char *p = NULL;
 #endif
 
+	ZEND_ASSERT(ZSTR_LEN(unescaped_cmd) == strlen(ZSTR_VAL(unescaped_cmd)) && "Must be a binary safe string");
+	size_t l = ZSTR_LEN(unescaped_cmd);
+	const char *str = ZSTR_VAL(unescaped_cmd);
+
+	uint64_t estimate = (2 * (uint64_t)l) + 1;
+
 	/* max command line length - two single quotes - \0 byte length */
 	if (l > cmd_max_len - 2 - 1) {
 		php_error_docref(NULL, E_ERROR, "Command exceeds the allowed length of %zu bytes", cmd_max_len);
@@ -471,18 +475,13 @@ PHPAPI zend_string *php_escape_shell_arg(const char *str)
 /* {{{ Escape shell metacharacters */
 PHP_FUNCTION(escapeshellcmd)
 {
-	char *command;
-	size_t command_len;
+	zend_string *command;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
-		Z_PARAM_STRING(command, command_len)
+		Z_PARAM_PATH_STR(command)
 	ZEND_PARSE_PARAMETERS_END();
 
-	if (command_len) {
-		if (command_len != strlen(command)) {
-			zend_argument_value_error(1, "must not contain any null bytes");
-			RETURN_THROWS();
-		}
+	if (ZSTR_LEN(command)) {
 		RETVAL_STR(php_escape_shell_cmd(command));
 	} else {
 		RETVAL_EMPTY_STRING();

ext/standard/exec.h

@@ -20,7 +20,7 @@
 PHP_MINIT_FUNCTION(proc_open);
 PHP_MINIT_FUNCTION(exec);
 
-PHPAPI zend_string *php_escape_shell_cmd(const char *str);
+PHPAPI zend_string *php_escape_shell_cmd(const zend_string *unescaped_cmd);
 PHPAPI zend_string *php_escape_shell_arg(const char *str);
 PHPAPI int php_exec(int type, const char *cmd, zval *array, zval *return_value);
 

ext/standard/mail.c

@@ -313,9 +313,9 @@ PHP_FUNCTION(mail)
 
 	zend_string *force_extra_parameters = zend_ini_str_ex("mail.force_extra_parameters", strlen("mail.force_extra_parameters"), false, NULL);
 	if (force_extra_parameters) {
-		extra_cmd = php_escape_shell_cmd(ZSTR_VAL(force_extra_parameters));
+		extra_cmd = php_escape_shell_cmd(force_extra_parameters);
 	} else if (extra_cmd) {
-		extra_cmd = php_escape_shell_cmd(ZSTR_VAL(extra_cmd));
+		extra_cmd = php_escape_shell_cmd(extra_cmd);
 	}
 
 	if (php_mail(to_r, subject_r, message, headers_str && ZSTR_LEN(headers_str) ? ZSTR_VAL(headers_str) : NULL, extra_cmd ? ZSTR_VAL(extra_cmd) : NULL)) {