Improve openssl_random_pseudo_bytes()

SammyK · SammyK · commit db44309d0c06 · 2018-11-19T18:14:53.000-05:00
CSPRNG implementations should always fail closed. Now
openssl_random_pseudo_bytes() will fail closed by throwing an
`\Exception` in fail conditions.
diff --git a/ext/openssl/openssl.c b/ext/openssl/openssl.c
@@ -28,6 +28,7 @@
 #include "php.h"
 #include "php_ini.h"
 #include "php_openssl.h"
+#include "zend_exceptions.h"
 
 /* PHP Includes */
 #include "ext/standard/file.h"
@@ -6861,7 +6862,8 @@ PHP_FUNCTION(openssl_random_pseudo_bytes)
 		|| ZEND_LONG_INT_OVFL(buffer_length)
 #endif
 			) {
-		RETURN_FALSE;
+		zend_throw_exception(zend_ce_error, "Length must be greater than 0", 0);
+		return;
 	}
 	buffer = zend_string_alloc(buffer_length, 0);
 
@@ -6872,7 +6874,8 @@ PHP_FUNCTION(openssl_random_pseudo_bytes)
 		if (zstrong_result_returned) {
 			ZVAL_FALSE(zstrong_result_returned);
 		}
-		RETURN_FALSE;
+		zend_throw_exception(zend_ce_exception, "Error reading from source device", 0);
+		return;
 	}
 #else
 
@@ -6884,7 +6887,8 @@ PHP_FUNCTION(openssl_random_pseudo_bytes)
 		if (zstrong_result_returned) {
 			ZVAL_FALSE(zstrong_result_returned);
 		}
-		RETURN_FALSE;
+		zend_throw_exception(zend_ce_exception, "Error reading from source device", 0);
+		return;
 	} else {
 		php_openssl_store_errors();
 	}
diff --git a/ext/openssl/tests/openssl_random_pseudo_bytes_basic.phpt b/ext/openssl/tests/openssl_random_pseudo_bytes_basic.phpt
@@ -4,13 +4,11 @@ openssl_random_pseudo_bytes() tests
 <?php if (!extension_loaded("openssl")) print "skip"; ?>
 --FILE--
 <?php
-for ($i = 0; $i < 10; $i++) {
-    var_dump(bin2hex(openssl_random_pseudo_bytes($i, $strong)));
+for ($i = 1; $i < 10; $i++) {
+    var_dump(bin2hex(openssl_random_pseudo_bytes($i)));
 }
-
 ?>
 --EXPECTF--
-string(0) ""
 string(2) "%s"
 string(4) "%s"
 string(6) "%s"
diff --git a/ext/openssl/tests/openssl_random_pseudo_bytes_error.phpt b/ext/openssl/tests/openssl_random_pseudo_bytes_error.phpt
@@ -0,0 +1,14 @@
+--TEST--
+Test error operation of openssl_random_pseudo_bytes()
+--SKIPIF--
+<?php if (!extension_loaded("openssl")) print "skip"; ?>
+--FILE--
+<?php
+try {
+    openssl_random_pseudo_bytes(0);
+} catch (Error $e) {
+    echo $e->getMessage().PHP_EOL;
+}
+?>
+--EXPECTF--
+Length must be greater than 0
