Let's get random: Under the hood of PHP 7's CSPRNG - ZendCon & OpenEnterprise 2018

Talk given at ZendCon & OpenEnterprise 2018

Randomness is really important in many cryptographic contexts. Unfortunately, true randomness is a non-trivial achievement for computers. In fact, using weak sources of randomness can leave your application open to myriad vulnerabilities. Enter a good cryptographically secure pseudorandom number generator (CSPRNG).

We’ll discuss the importance of using good sources of randomness, the CSPRNG options we had in PHP 5, and how the new-goodness CSPRNG functions in PHP 7 work under the hood.

Transcript

1. Random Under the hood of PHP 7’s Let’s get CSPRNG Sammy Kaye Powers Las Vegas, NV - 2018
2. joind.in/talk/0e3b7 @SammyK #zcoe18 Slides Get the joind.in/talk/0e3b7
3. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG? What is the PHP 7
4. joind.in/talk/0e3b7 @SammyK #zcoe18 random_int() random_bytes()
5. joind.in/talk/0e3b7 @SammyK #zcoe18 ext/standard/random.c
6. joind.in/talk/0e3b7 @SammyK #zcoe18 The end
7. joind.in/talk/0e3b7 @SammyK #zcoe18 Random? What is
8. Red Yellow White Red Yellow White Red Yellow White Period: 3
9. Jingle all the way, Oh what fun it is to ride In a one-horse open sleigh Predictable seed Jingle bells, jingle bells
10. 74, 105, 110, 103, 108, 101, 32, 97, 108, 108, 32, 116, 104, 101, 32, 119, 97, 121, 44 Random, right?
11. ASCII
12. 74, 105, 110, 103, 108, 101, 32, chr() J, i, n, g, l, e, ,
13. 97, 108, 108, 32, What’s the next word? a, l, l, ,
14. 116, 104, 101, 32, t, h, e, ,
15. 74, 105, 110, 103, 108, 101, 32, 97, 108, 108, 32, Random, right? 116, 104, 101, 32, nope!
16. Felt? Remember how we
17. 74, 105, 110, 103, 108, 101, 32, 97, 108, 108, 32, 116, 104, 101, 32, 119, 97, 121, 44 What’s the meaning? ASCII codes! Ah, right. Carry on then. Deterministic
18. joind.in/talk/0e3b7 @SammyK #zcoe18 Why did we think
19. joind.in/talk/0e3b7 @SammyK #zcoe18 •Think of a two-digit number •Between one and one hundred •Both digits odd •Both digits different
20. joind.in/talk/0e3b7 @SammyK #zcoe18 Are you thinking of… 37
21. joind.in/talk/0e3b7 @SammyK #zcoe18 Humans are bad at being random
22. joind.in/talk/0e3b7 @SammyK #zcoe18 Environment Can we use our to make better random numbers?
23. joind.in/talk/0e3b7 @SammyK #zcoe18 Time? Maybe the
24. joind.in/talk/0e3b7 @SammyK #zcoe18 12:00, 12:01, 12:02, 12:03, 12:04, 12:05, 12:06, 12:07, 12:08, 12:09, 12:10, 12:11, 12:12, 12:13, 12:14, 12:15, 12:16, 12:17, 12:18, 12:19, 12:20, 12:21, 12:22, 12:23, 12:24, 12:25, 12:26, 12:27, 12:28, 12:29, 12:30, 12:31, 12:32, 12:33, 12:34, 12:35, 12:36, 12:37, 12:38, 12:39, 12:40, 12:41, 12:42, 12:43, 12:44, 12:45, 12:46, 12:47, 12:48, 12:49, 12:50, 12:51, 12:52, 12:53, 12:54, 12:55, 12:56, 12:57, 12:58, 12:59, 1:00, 1:01, 1:02, 1:03, 1:04, 1:05, 1:06, 1:07, 1:08, 1:09, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, 1:50, 1:51, 1:52, 1:53, 1:54, 1:55, 1:56, 1:57, 1:58, 1:59, 2:00, 2:01, 2:02, 2:03, 2:04, 2:05, 2:06, 2:07, 2:08, 2:09, 2:10, 2:11, 2:12, 2:13, 2:14, 2:15, 2:16, 2:17, 2:18, 2:19, 2:20, 2:21, 2:22, 2:23, 2:24, 2:25, 2:26, 2:27, 2:28, 2:29, 2:30, 2:31, 2:32, 2:33, 2:34, 2:35, 2:36, 2:37, 2:38, 2:39, 2:40, 2:41, 2:42, 2:43, 2:44, 2:45, 2:46, 2:47, 2:48, 2:49, 2:50, 2:51, 2:52, 2:53, 2:54, 2:55, 2:56, 2:57, 2:58, 2:59, 3:00, 3:01, 3:02, 3:03, 3:04, 3:05, 3:06, 3:07, 3:08, 3:09, 3:10, 3:11, 3:12, 3:13, 3:14, 3:15, 3:16, 3:17, 3:18, 3:19, 3:20, 3:21, 3:22, 3:23, 3:24, 3:25, 3:26, 3:27, 3:28, 3:29, 3:30, 3:31, 3:32, 3:33, 3:34, 3:35, 3:36, 3:37, 3:38, 3:39, 3:40, 3:41, 3:42, 3:43, 3:44, 3:45, 3:46, 3:47, 3:48, 3:49, 3:50, 3:51, 3:52, 3:53, 3:54, 3:55, 3:56, 3:57, 3:58, 3:59, 4:00, 4:01, 4:02, 4:03, 4:04, 4:05, 4:06, 4:07, 4:08, 4:09, 4:10, 4:11, 4:12, 4:13, 4:14, 4:15, 4:16, 4:17, 4:18, 4:19, 4:20, 4:21, 4:22, 4:23, 4:24, 4:25, 4:26, 4:27, 4:28, 4:29, 4:30, 4:31, 4:32, 4:33, 4:34, 4:35, 4:36, 4:37, 4:38, 4:39, 4:40, 4:41, 4:42, 4:43, 4:44, 4:45, 4:46, 4:47, 4:48, 4:49, 4:50, 4:51, 4:52, 4:53, 4:54, 4:55, 4:56, 4:57, 4:58, 4:59, 5:00, 5:01, 5:02, 5:03, 5:04, 5:05, 5:06, 5:07, 5:08, 5:09, 5:10, 5:11, 5:12, 5:13, 5:14, 5:15, 5:16, 5:17, 5:18, 5:19, 5:20, 5:21, 5:22, 5:23, 5:24, 5:25, 5:26, 5:27, 5:28, 5:29, 5:30, 5:31, 5:32, 5:33, 5:34, 5:35, 5:36, 5:37, 5:38, 5:39, 5:40, 5:41, 5:42, 5:43, 5:44, 5:45, 5:46, 5:47, 5:48, 5:49, 5:50, 5:51, 5:52, 5:53, 5:54, 5:55, 5:56, 5:57, 5:58, 5:59, 6:00, 6:01, 6:02, 6:03, 6:04, 6:05, 6:06, 6:07, 6:08, 6:09, 6:10, 6:11, 6:12, 6:13, 6:14, 6:15, 6:16, 6:17, 6:18, 6:19, 6:20, 6:21, 6:22, 6:23, 6:24, 6:25, 6:26, 6:27, 6:28, 6:29, 6:30, 6:31, 6:32, 6:33, 6:34, 6:35, 6:36, 6:37, 6:38, 6:39, 6:40, 6:41, 6:42, 6:43, 6:44, 6:45, 6:46, 6:47, 6:48, 6:49, 6:50, 6:51, 6:52, 6:53, 6:54, 6:55, 6:56, 6:57, 6:58, 6:59, 7:00, 7:01, 7:02, 7:03, 7:04, 7:05, 7:06, 7:07, 7:08, 7:09, 7:10, 7:11, 7:12, 7:13, 7:14, 7:15, 7:16, 7:17, 7:18, 7:19, 7:20, 7:21, 7:22, 7:23, 7:24, 7:25, 7:26, 7:27, 7:28, 7:29, 7:30, 7:31, 7:32, 7:33, 7:34, 7:35, 7:36, 7:37, 7:38, 7:39, 7:40, 7:41, 7:42, 7:43, 7:44, 7:45, 7:46, 7:47, 7:48, 7:49, 7:50, 7:51, 7:52, 7:53, 7:54, 7:55, 7:56, 7:57, 7:58, 7:59, 8:00, 8:01, 8:02, 8:03, 8:04, 8:05, 8:06, 8:07, 8:08, 8:09, 8:10, 8:11, 8:12, 8:13, 8:14, 8:15, 8:16, 8:17, 8:18, 8:19, 8:20, 8:21, 8:22, 8:23, 8:24, 8:25, 8:26, 8:27, 8:28, 8:29, 8:30, 8:31, 8:32, 8:33, 8:34, 8:35, 8:36, 8:37, 8:38, 8:39, 8:40, 8:41, 8:42, 8:43, 8:44, 8:45, 8:46, 8:47, 8:48, 8:49, 8:50, 8:51, 8:52, 8:53, 8:54, 8:55, 8:56, 8:57, 8:58, 8:59, 9:00, 9:01, 9:02, 9:03, 9:04, 9:05, 9:06, 9:07, 9:08, 9:09, 9:10, 9:11, 9:12, 9:13, 9:14, 9:15, 9:16, 9:17, 9:18, 9:19, 9:20, 9:21, 9:22, 9:23, 9:24, 9:25, 9:26, 9:27, 9:28, 9:29, 9:30, 9:31, 9:32, 9:33, 9:34, 9:35, 9:36, 9:37, 9:38, 9:39, 9:40, 9:41, 9:42, 9:43, 9:44, 9:45, 9:46, 9:47, 9:48, 9:49, 9:50, 9:51, 9:52, 9:53, 9:54, 9:55, 9:56, 9:57, 9:58, 9:59, 10:00, 10:01, 10:02, 10:03, 10:04, 10:05, 10:06, 10:07, 10:08, 10:09, 10:10, 10:11, 10:12, 10:13, 10:14, 10:15, 10:16, 10:17, 10:18, 10:19, 10:20, 10:21, 10:22, 10:23, 10:24, 10:25, 10:26, 10:27, 10:28, 10:29, 10:30, 10:31, 10:32, 10:33, 10:34, 10:35, 10:36, 10:37, 10:38, 10:39, 10:40, 10:41, 10:42, 10:43, 10:44, 10:45, 10:46, 10:47, 10:48, 10:49, 10:50, 10:51, 10:52, 10:53, 10:54, 10:55, 10:56, 10:57, 10:58, 10:59, 11:00, 11:01, 11:02, 11:03, 11:04, 11:05, 11:06, 11:07, 11:08, 11:09, 11:10, 11:11, 11:12, 11:13, 11:14, 11:15, 11:16, 11:17, 11:18, 11:19, 11:20, 11:21, 11:22, 11:23, 11:24, 11:25, 11:26, 11:27, 11:28, 11:29, 11:30, 11:31, 11:32, 11:33, 11:34, 11:35, 11:36, 11:37, 11:38, 11:39, 11:40, 11:41, 11:42, 11:43, 11:44, 11:45, 11:46, 11:47, 11:48, 11:49, 11:50, 11:51, 11:52, 11:53, 11:54, 11:55, 11:56, 11:57, 11:58, 11:59 720
25. joind.in/talk/0e3b7 @SammyK #zcoe18 12:00, 12:01, 12:02, 12:03, 12:04, 12:05, 12:06, 12:07, 12:08, 12:09, 12:10, 12:11, 12:12, 12:13, 12:14, 12:15, 12:16, 12:17, 12:18, 12:19, 12:20, 12:21, 12:22, 12:23, 12:24, 12:25, 12:26, 12:27, 12:28, 12:29, 12:30, 12:31, 12:32, 12:33, 12:34, 12:35, 12:36, 12:37, 12:38, 12:39, 12:40, 12:41, 12:42, 12:43, 12:44, 12:45, 12:46, 12:47, 12:48, 12:49, 12:50, 12:51, 12:52, 12:53, 12:54, 12:55, 12:56, 12:57, 12:58, 12:59, 1:00, 1:01, 1:02, 1:03, 1:04, 1:05, 1:06, 1:07, 1:08, 1:09, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, 1:50, 1:51, 1:52, 1:53, 1:54, 1:55, 1:56, 1:57, 1:58, 1:59, 2:00, 2:01, 2:02, 2:03, 2:04, 2:05, 2:06, 2:07, 2:08, 2:09, 2:10, 2:11, 2:12, 2:13, 2:14, 2:15, 2:16, 2:17, 2:18, 2:19, 2:20, 2:21, 2:22, 2:23, 2:24, 2:25, 2:26, 2:27, 2:28, 2:29, 2:30, 2:31, 2:32, 2:33, 2:34, 2:35, 2:36, 2:37, 2:38, 2:39, 2:40, 2:41, 2:42, 2:43, 2:44, 2:45, 2:46, 2:47, 2:48, 2:49, 2:50, 2:51, 2:52, 2:53, 2:54, 2:55, 2:56, 2:57, 2:58, 2:59, 3:00, 3:01, 3:02, 3:03, 3:04, 3:05, 3:06, 3:07, 3:08, 3:09, 3:10, 3:11, 3:12, 3:13, 3:14, 3:15, 3:16, 3:17, 3:18, 3:19, 3:20, 3:21, 3:22, 3:23, 3:24, 3:25, 3:26, 3:27, 3:28, 3:29, 3:30, 3:31, 3:32, 3:33, 3:34, 3:35, 3:36, 3:37, 3:38, 3:39, 3:40, 3:41, 3:42, 3:43, 3:44, 3:45, 3:46, 3:47, 3:48, 3:49, 3:50, 3:51, 3:52, 3:53, 3:54, 3:55, 3:56, 3:57, 3:58, 3:59, 4:00, 4:01, 4:02, 4:03, 4:04, 4:05, 4:06, 4:07, 4:08, 4:09, 4:10, 4:11, 4:12, 4:13, 4:14, 4:15, 4:16, 4:17, 4:18, 4:19, 4:20, 4:21, 4:22, 4:23, 4:24, 4:25, 4:26, 4:27, 4:28, 4:29, 4:30, 4:31, 4:32, 4:33, 4:34, 4:35, 4:36, 4:37, 4:38, 4:39, 4:40, 4:41, 4:42, 4:43, 4:44, 4:45, 4:46, 4:47, 4:48, 4:49, 4:50, 4:51, 4:52, 4:53, 4:54, 4:55, 4:56, 4:57, 4:58, 4:59, 5:00, 5:01, 5:02, 5:03, 5:04, 5:05, 5:06, 5:07, 5:08, 5:09, 5:10, 5:11, 5:12, 5:13, 5:14, 5:15, 5:16, 5:17, 5:18, 5:19, 5:20, 5:21, 5:22, 5:23, 5:24, 5:25, 5:26, 5:27, 5:28, 5:29, 5:30, 5:31, 5:32, 5:33, 5:34, 5:35, 5:36, 5:37, 5:38, 5:39, 5:40, 5:41, 5:42, 5:43, 5:44, 5:45, 5:46, 5:47, 5:48, 5:49, 5:50, 5:51, 5:52, 5:53, 5:54, 5:55, 5:56, 5:57, 5:58, 5:59, 6:00, 6:01, 6:02, 6:03, 6:04, 6:05, 6:06, 6:07, 6:08, 6:09, 6:10, 6:11, 6:12, 6:13, 6:14, 6:15, 6:16, 6:17, 6:18, 6:19, 6:20, 6:21, 6:22, 6:23, 6:24, 6:25, 6:26, 6:27, 6:28, 6:29, 6:30, 6:31, 6:32, 6:33, 6:34, 6:35, 6:36, 6:37, 6:38, 6:39, 6:40, 6:41, 6:42, 6:43, 6:44, 6:45, 6:46, 6:47, 6:48, 6:49, 6:50, 6:51, 6:52, 6:53, 6:54, 6:55, 6:56, 6:57, 6:58, 6:59, 7:00, 7:01, 7:02, 7:03, 7:04, 7:05, 7:06, 7:07, 7:08, 7:09, 7:10, 7:11, 7:12, 7:13, 7:14, 7:15, 7:16, 7:17, 7:18, 7:19, 7:20, 7:21, 7:22, 7:23, 7:24, 7:25, 7:26, 7:27, 7:28, 7:29, 7:30, 7:31, 7:32, 7:33, 7:34, 7:35, 7:36, 7:37, 7:38, 7:39, 7:40, 7:41, 7:42, 7:43, 7:44, 7:45, 7:46, 7:47, 7:48, 7:49, 7:50, 7:51, 7:52, 7:53, 7:54, 7:55, 7:56, 7:57, 7:58, 7:59, 8:00, 8:01, 8:02, 8:03, 8:04, 8:05, 8:06, 8:07, 8:08, 8:09, 8:10, 8:11, 8:12, 8:13, 8:14, 8:15, 8:16, 8:17, 8:18, 8:19, 8:20, 8:21, 8:22, 8:23, 8:24, 8:25, 8:26, 8:27, 8:28, 8:29, 8:30, 8:31, 8:32, 8:33, 8:34, 8:35, 8:36, 8:37, 8:38, 8:39, 8:40, 8:41, 8:42, 8:43, 8:44, 8:45, 8:46, 8:47, 8:48, 8:49, 8:50, 8:51, 8:52, 8:53, 8:54, 8:55, 8:56, 8:57, 8:58, 8:59, 9:00, 9:01, 9:02, 9:03, 9:04, 9:05, 9:06, 9:07, 9:08, 9:09, 9:10, 9:11, 9:12, 9:13, 9:14, 9:15, 9:16, 9:17, 9:18, 9:19, 9:20, 9:21, 9:22, 9:23, 9:24, 9:25, 9:26, 9:27, 9:28, 9:29, 9:30, 9:31, 9:32, 9:33, 9:34, 9:35, 9:36, 9:37, 9:38, 9:39, 9:40, 9:41, 9:42, 9:43, 9:44, 9:45, 9:46, 9:47, 9:48, 9:49, 9:50, 9:51, 9:52, 9:53, 9:54, 9:55, 9:56, 9:57, 9:58, 9:59, 10:00, 10:01, 10:02, 10:03, 10:04, 10:05, 10:06, 10:07, 10:08, 10:09, 10:10, 10:11, 10:12, 10:13, 10:14, 10:15, 10:16, 10:17, 10:18, 10:19, 10:20, 10:21, 10:22, 10:23, 10:24, 10:25, 10:26, 10:27, 10:28, 10:29, 10:30, 10:31, 10:32, 10:33, 10:34, 10:35, 10:36, 10:37, 10:38, 10:39, 10:40, 10:41, 10:42, 10:43, 10:44, 10:45, 10:46, 10:47, 10:48, 10:49, 10:50, 10:51, 10:52, 10:53, 10:54, 10:55, 10:56, 10:57, 10:58, 10:59, 11:00, 11:01, 11:02, 11:03, 11:04, 11:05, 11:06, 11:07, 11:08, 11:09, 11:10, 11:11, 11:12, 11:13, 11:14, 11:15, 11:16, 11:17, 11:18, 11:19, 11:20, 11:21, 11:22, 11:23, 11:24, 11:25, 11:26, 11:27, 11:28, 11:29, 11:30, 11:31, 11:32, 11:33, 11:34, 11:35, 11:36, 11:37, 11:38, 11:39, 11:40, 11:41, 11:42, 11:43, 11:44, 11:45, 11:46, 11:47, 11:48, 11:49, 11:50, 11:51, 11:52, 11:53, 11:54, 11:55, 11:56, 11:57, 11:58, 11:59 BUT!
26. joind.in/talk/0e3b7 @SammyK #zcoe18 12:00, 12:01, 12:02, 12:03, 12:04, 12:05, 12:06, 12:07, 12:08, 12:09, 12:10, 12:11, 12:12, 12:13, 12:14, 12:15, 12:16, 12:17, 12:18, 12:19, 12:20, 12:21, 12:22, 12:23, 12:24, 12:25, 12:26, 12:27, 12:28, 12:29, 12:30, 12:31, 12:32, 12:33, 12:34, 12:35, 12:36, 12:37, 12:38, 12:39, 12:40, 12:41, 12:42, 12:43, 12:44, 12:45, 12:46, 12:47, 12:48, 12:49, 12:50, 12:51, 12:52, 12:53, 12:54, 12:55, 12:56, 12:57, 12:58, 12:59, 1:00, 1:01, 1:02, 1:03, 1:04, 1:05, 1:06, 1:07, 1:08, 1:09, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, 1:50, 1:51, 1:52, 1:53, 1:54, 1:55, 1:56, 1:57, 1:58, 1:59, 2:00, 2:01, 2:02, 2:03, 2:04, 2:05, 2:06, 2:07, 2:08, 2:09, 2:10, 2:11, 2:12, 2:13, 2:14, 2:15, 2:16, 2:17, 2:18, 2:19, 2:20, 2:21, 2:22, 2:23, 2:24, 2:25, 2:26, 2:27, 2:28, 2:29, 2:30, 2:31, 2:32, 2:33, 2:34, 2:35, 2:36, 2:37, 2:38, 2:39, 2:40, 2:41, 2:42, 2:43, 2:44, 2:45, 2:46, 2:47, 2:48, 2:49, 2:50, 2:51, 2:52, 2:53, 2:54, 2:55, 2:56, 2:57, 2:58, 2:59, 3:00, 3:01, 3:02, 3:03, 3:04, 3:05, 3:06, 3:07, 3:08, 3:09, 3:10, 3:11, 3:12, 3:13, 3:14, 3:15, 3:16, 3:17, 3:18, 3:19, 3:20, 3:21, 3:22, 3:23, 3:24, 3:25, 3:26, 3:27, 3:28, 3:29, 3:30, 3:31, 3:32, 3:33, 3:34, 3:35, 3:36, 3:37, 3:38, 3:39, 3:40, 3:41, 3:42, 3:43, 3:44, 3:45, 3:46, 3:47, 3:48, 3:49, 3:50, 3:51, 3:52, 3:53, 3:54, 3:55, 3:56, 3:57, 3:58, 3:59, 4:00, 4:01, 4:02, 4:03, 4:04, 4:05, 4:06, 4:07, 4:08, 4:09, 4:10, 4:11, 4:12, 4:13, 4:14, 4:15, 4:16, 4:17, 4:18, 4:19, 4:20, 4:21, 4:22, 4:23, 4:24, 4:25, 4:26, 4:27, 4:28, 4:29, 4:30, 4:31, 4:32, 4:33, 4:34, 4:35, 4:36, 4:37, 4:38, 4:39, 4:40, 4:41, 4:42, 4:43, 4:44, 4:45, 4:46, 4:47, 4:48, 4:49, 4:50, 4:51, 4:52, 4:53, 4:54, 4:55, 4:56, 4:57, 4:58, 4:59, 5:00, 5:01, 5:02, 5:03, 5:04, 5:05, 5:06, 5:07, 5:08, 5:09, 5:10, 5:11, 5:12, 5:13, 5:14, 5:15, 5:16, 5:17, 5:18, 5:19, 5:20, 5:21, 5:22, 5:23, 5:24, 5:25, 5:26, 5:27, 5:28, 5:29, 5:30, 5:31, 5:32, 5:33, 5:34, 5:35, 5:36, 5:37, 5:38, 5:39, 5:40, 5:41, 5:42, 5:43, 5:44, 5:45, 5:46, 5:47, 5:48, 5:49, 5:50, 5:51, 5:52, 5:53, 5:54, 5:55, 5:56, 5:57, 5:58, 5:59, 6:00, 6:01, 6:02, 6:03, 6:04, 6:05, 6:06, 6:07, 6:08, 6:09, 6:10, 6:11, 6:12, 6:13, 6:14, 6:15, 6:16, 6:17, 6:18, 6:19, 6:20, 6:21, 6:22, 6:23, 6:24, 6:25, 6:26, 6:27, 6:28, 6:29, 6:30, 6:31, 6:32, 6:33, 6:34, 6:35, 6:36, 6:37, 6:38, 6:39, 6:40, 6:41, 6:42, 6:43, 6:44, 6:45, 6:46, 6:47, 6:48, 6:49, 6:50, 6:51, 6:52, 6:53, 6:54, 6:55, 6:56, 6:57, 6:58, 6:59, 7:00, 7:01, 7:02, 7:03, 7:04, 7:05, 7:06, 7:07, 7:08, 7:09, 7:10, 7:11, 7:12, 7:13, 7:14, 7:15, 7:16, 7:17, 7:18, 7:19, 7:20, 7:21, 7:22, 7:23, 7:24, 7:25, 7:26, 7:27, 7:28, 7:29, 7:30, 7:31, 7:32, 7:33, 7:34, 7:35, 7:36, 7:37, 7:38, 7:39, 7:40, 7:41, 7:42, 7:43, 7:44, 7:45, 7:46, 7:47, 7:48, 7:49, 7:50, 7:51, 7:52, 7:53, 7:54, 7:55, 7:56, 7:57, 7:58, 7:59, 8:00, 8:01, 8:02, 8:03, 8:04, 8:05, 8:06, 8:07, 8:08, 8:09, 8:10, 8:11, 8:12, 8:13, 8:14, 8:15, 8:16, 8:17, 8:18, 8:19, 8:20, 8:21, 8:22, 8:23, 8:24, 8:25, 8:26, 8:27, 8:28, 8:29, 8:30, 8:31, 8:32, 8:33, 8:34, 8:35, 8:36, 8:37, 8:38, 8:39, 8:40, 8:41, 8:42, 8:43, 8:44, 8:45, 8:46, 8:47, 8:48, 8:49, 8:50, 8:51, 8:52, 8:53, 8:54, 8:55, 8:56, 8:57, 8:58, 8:59, 9:00, 9:01, 9:02, 9:03, 9:04, 9:05, 9:06, 9:07, 9:08, 9:09, 9:10, 9:11, 9:12, 9:13, 9:14, 9:15, 9:16, 9:17, 9:18, 9:19, 9:20, 9:21, 9:22, 9:23, 9:24, 9:25, 9:26, 9:27, 9:28, 9:29, 9:30, 9:31, 9:32, 9:33, 9:34, 9:35, 9:36, 9:37, 9:38, 9:39, 9:40, 9:41, 9:42, 9:43, 9:44, 9:45, 9:46, 9:47, 9:48, 9:49, 9:50, 9:51, 9:52, 9:53, 9:54, 9:55, 9:56, 9:57, 9:58, 9:59, 10:00, 10:01, 10:02, 10:03, 10:04, 10:05, 10:06, 10:07, 10:08, 10:09, 10:10, 10:11, 10:12, 10:13, 10:14, 10:15, 10:16, 10:17, 10:18, 10:19, 10:20, 10:21, 10:22, 10:23, 10:24, 10:25, 10:26, 10:27, 10:28, 10:29, 10:30, 10:31, 10:32, 10:33, 10:34, 10:35, 10:36, 10:37, 10:38, 10:39, 10:40, 10:41, 10:42, 10:43, 10:44, 10:45, 10:46, 10:47, 10:48, 10:49, 10:50, 10:51, 10:52, 10:53, 10:54, 10:55, 10:56, 10:57, 10:58, 10:59, 11:00, 11:01, 11:02, 11:03, 11:04, 11:05, 11:06, 11:07, 11:08, 11:09, 11:10, 11:11, 11:12, 11:13, 11:14, 11:15, 11:16, 11:17, 11:18, 11:19, 11:20, 11:21, 11:22, 11:23, 11:24, 11:25, 11:26, 11:27, 11:28, 11:29, 11:30, 11:31, 11:32, 11:33, 11:34, 11:35, 11:36, 11:37, 11:38, 11:39, 11:40, 11:41, 11:42, 11:43, 11:44, 11:45, 11:46, 11:47, 11:48, 11:49, 11:50, 11:51, 11:52, 11:53, 11:54, 11:55, 11:56, 11:57, 11:58, 11:59 • Session started at 4:00 pm PDT • That was on slide #23 • If you timed my rehearsals…
27. joind.in/talk/0e3b7 @SammyK #zcoe18 11 random? What makes a number
28. joind.in/talk/0e3b7 @SammyK #zcoe18 2, 4, 6, 8, __ 10
29. joind.in/talk/0e3b7 @SammyK #zcoe18 1337, 42, 0, _ ?
30. joind.in/talk/0e3b7 @SammyK #zcoe18 1337, 42, 0, 1337, 42, 0, 1337, __ 42
31. joind.in/talk/0e3b7 @SammyK #zcoe18 Random? What is isn’t Deterministic
32. joind.in/talk/0e3b7 @SammyK #zcoe18 “True” Random Measurement of atmospheric noise Count of the number of electrons coming off of a radioactive material
34. joind.in/talk/0e3b7 @SammyK #zcoe18 Can I haz random number?
35. joind.in/talk/0e3b7 @SammyK #zcoe18
36. joind.in/talk/0e3b7 @SammyK #zcoe18
37. joind.in/talk/0e3b7 @SammyK #zcoe18 *sigh* Take this. 42
38. joind.in/talk/0e3b7 @SammyK #zcoe18
39. joind.in/talk/0e3b7 @SammyK #zcoe18 0
40. joind.in/talk/0e3b7 @SammyK #zcoe18 2,4,8, 7,5,1 ?
41. joind.in/talk/0e3b7 @SammyK #zcoe18 Number Generator …or “PRNG” for short Pseudorandom
42. joind.in/talk/0e3b7 @SammyK #zcoe18 Pseudorandom? How’s that different than just random? Deterministic
43. joind.in/talk/0e3b7 @SammyK #zcoe18 2,4,8, 7,5,1 Generator Linear Congruential
44. joind.in/talk/0e3b7 @SammyK #zcoe18 Generator Linear Congruential
45. joind.in/talk/0e3b7 @SammyK #zcoe18
46. joind.in/talk/0e3b7 @SammyK #zcoe18 The modulus The multiplier The increment The seed
47. joind.in/talk/0e3b7 @SammyK #zcoe18
48. joind.in/talk/0e3b7 @SammyK #zcoe18
49. joind.in/talk/0e3b7 @SammyK #zcoe18 2,4,8, 7,5,
50. joind.in/talk/0e3b7 @SammyK #zcoe18 2,4,8, 7,5, Deterministic
51. joind.in/talk/0e3b7 @SammyK #zcoe18 https://xkcd.com/221/
52. joind.in/talk/0e3b7 @SammyK #zcoe18
53. joind.in/talk/0e3b7 @SammyK #zcoe18
54. joind.in/talk/0e3b7 @SammyK #zcoe18 8,7,5, 1,2,
55. joind.in/talk/0e3b7 @SammyK #zcoe18 1,2,4, 8,7, BUT!
56. joind.in/talk/0e3b7 @SammyK #zcoe18
57. 5,1,2,4,8,7,5, 1,2,4,8,7,5,1, 2,4,8,7,5,1,2, 4,8,7,5,1,2,4, 8,7,5,1,2,4,8, 7,5,1,2,4, Predictable Period: 6
58. joind.in/talk/0e3b7 @SammyK #zcoe18 LCG lcg_value() PHP has a combined
59. joind.in/talk/0e3b7 @SammyK #zcoe18 PRNG? Is there a better
60. joind.in/talk/0e3b7 @SammyK #zcoe18 Twister Mersenne mt_rand()
61. joind.in/talk/0e3b7 @SammyK #zcoe18
62. mt_rand() 724937621,955931554,1407935661,821438740,109344 9922,603009103,1540988686,1028238631,798475733, 1057939018,671583233,1853117923,98760648,112245 3373,534404057,900958085,1712824654,476385742,2 9956470,362833620,424798798,746223917,942003531 ,320462445,673296853,1351199651,141566289,16454 09515,995047403,1216151582,1115999460,175322091 7,1312071810,1553254094,1622498991,2080099801,1 704834715,1537620663,1357630828,1317892558, 219,937-1
63. joind.in/talk/0e3b7 @SammyK #zcoe18
64. mt_rand(0,99) 83,9,64,28,62,48,83,47,46,53,37,26,21,91,61,32,58,1,89,60,65,97,42,56,6,47,76,1 2,98,11,36,61,62,60,43,67,6,16,73,15,39,38,56,19,66,56,98,72,91,24,57,94,8,26,7 3,55,17,14,84,89,39,11,13,48,71,98,89,63,9,95,74,9,81,85,97,24,14,14,77,22,96,4 3,61,91,61,58,19,71,8,49,18,92,38,34,9,36,91,59,14,4,58,59,29,74,52,41,36,67,82 ,67,11,0,58,51,37,4,45,56,35,50,78,91,27,39,80,27,28,95,2,82,51,72,27,41,43,74, 7,82,59,89,72,9,22,61,75,27,64,16,77,57,31,29,59,47,14,67,89,33,94,33,94,22,11, 62,9,13,61,45,78,29,3,11,99,91,52,79,63,64,43,99,53,22,16,10,53,57,15,84,16,30, 17,10,3,35,0,45,83,11,70,66,37,14,59,41,46,52,53,53,62,56,41,82,40,99,8,92,96,2 2,22,43,35,60,45,77,26,96,45,51,62,77,64,23,52,17,17,97,93,57,43,56,45,62,42,24 ,62,1,59,38,70,13,34,32,48,47,1,42,48,18,2,59,47,53,10,3,66,68,93,4,53,85,20,77 ,63,43,45,16,15,77,73,89,11,64,76,30,46,91,1,85,96,19,63,70,62,35,58,95,63,38,7 8,83,8,97,22,2,28,51,25,29,98,62,74,59,95,79,74,66,47,35,83,56,49,25,32,25,46,1 3,69,77,30,94,24,31,68,23,64,47,28,33,65,69,16,0,98,37,85,93,60,24,10,54,50,42, 64,11,9,13,15,84,3,23,73,83,83,72,9,2,28,23,90,73,2,47,45,93,4,32,25,75,61,98,7 3,79,66,23,20,83,11,45,67,40,39,45,0,65,40,78,74,8,79,86,38,10,87,60,99,30,35,5 0,16,29,24,19,29,16,40,57,87,26,90,1,63,63,34,44,8,36,25,38,50,10,15,17,14,40,6 ,53,88,18,36,46,69,2,13,0,83,59,92,59,34,34,24,40,99,41,6,79,65,98,9,36,31,8,4, 89,98,91,80,42,10,26,72,40,50,39,25,33,45,24,70,54,89,91,53,23,12,20,40,21,25,5 5,48,11,3,84,42,5,7,21,58,85,18,52,92,94,69,20,49,3,8,55,57,4,38,52,37,64,55,82 ,98,5,75,84,35,14,99,74,23,41,69,55,53,22,52,6,68,35,38,73,52,22,52,86,79,15,38 ,3,20,99,36,23,77,33,80,16,97,54,88,11,77,77,99,70,26,5,75,87,4,23,8,50,79,61,5 5,80,25,58,79,25,56,9,81,6,42,27,90,58,6,62,74,25,79,81,61,23,54,92,53,16,66,22 ,49,77,97,84,25,49,32,49,65,51,1,93,63,68,69,67,10,44,99,44,42,89,35,24, 624 = busted
65. echo mt_rand(0,99); 11
66. echo mt_rand(0,99); 9
67. echo mt_rand(0,99); 60
68. mt_srand(10); echo mt_rand(0,99); 21
69. mt_srand(10); echo mt_rand(0,99); 21
70. mt_srand(10); echo mt_rand(0,99); 21
72. joind.in/talk/0e3b7 @SammyK #zcoe18 Good randomness can be Deterministic (e.g. games)
73. joind.in/talk/0e3b7 @SammyK #zcoe18
74. joind.in/talk/0e3b7 @SammyK #zcoe18
75. joind.in/talk/0e3b7 @SammyK #zcoe18
76. joind.in/talk/0e3b7 @SammyK #zcoe18 AKA “Seed”
77. joind.in/talk/0e3b7 @SammyK #zcoe18
78. joind.in/talk/0e3b7 @SammyK #zcoe18
79. joind.in/talk/0e3b7 @SammyK #zcoe18 deterministic randomness is contexts In cryptographic really, really, really, really objectively…
80. joind.in/talk/0e3b7 @SammyK #zcoe18 BAD
81. joind.in/talk/0e3b7 @SammyK #zcoe18 CSRF Take for example Tokens
82. joind.in/talk/0e3b7 @SammyK #zcoe18 Cross-site request forgery (CSRF) tokens help prevent unauthorized requests on a user’s behalf.
83. joind.in/talk/0e3b7 @SammyK #zcoe18 A CSRF token must be unique and unpredictable. *don’t do this
84. joind.in/talk/0e3b7 @SammyK #zcoe18
85. joind.in/talk/0e3b7 @SammyK #zcoe18
86. joind.in/talk/0e3b7 @SammyK #zcoe18
87. joind.in/talk/0e3b7 @SammyK #zcoe18 I’ll just let PHP seed mt_rand() for me. Bad idea jeans *Old SNL skit reference
88. joind.in/talk/0e3b7 @SammyK #zcoe18
89. joind.in/talk/0e3b7 @SammyK #zcoe18 What about rand() you ask?
90. joind.in/talk/0e3b7 @SammyK #zcoe18 Nope
91. joind.in/talk/0e3b7 @SammyK #zcoe18 rand() mt_rand() …in PHP 7.0 & below
92. joind.in/talk/0e3b7 @SammyK #zcoe18 rand() Uses the system PRNG (unreliable & inconsistent) Is a PRNG (totes predictable) Uniform distribution issues
93. joind.in/talk/0e3b7 @SammyK #zcoe18 Uniform Distribution
94. joind.in/talk/0e3b7 @SammyK #zcoe18 0 0.05 0.1 0.15 0.2 1 2 3 4 5 6
95. joind.in/talk/0e3b7 @SammyK #zcoe18 0 0.1 0.2 0.3 0.4 1 2 3 4 5 6
96. joind.in/talk/0e3b7 @SammyK #zcoe18 Uniform Distribution == True Random
97. joind.in/talk/0e3b7 @SammyK #zcoe18 mt_rand() Implements the MT algorithm incorrectly Is a PRNG (totes predictable) Has a modulo bias
98. joind.in/talk/0e3b7 @SammyK #zcoe18 Modulo Bias
99. joind.in/talk/0e3b7 @SammyK #zcoe18 6 % 3 = 0 8 % 3 = 2 Modulo Operator
100. joind.in/talk/0e3b7 @SammyK #zcoe18 Random # between 0 & 1 n % 2 = 0 or 1 Use mod 2
101. joind.in/talk/0e3b7 @SammyK #zcoe18 rand_src() = 1, 2, or 3 2 % 2 = 0 3 % 2 = 1 1 is more likely 1 % 2 = 1
102. joind.in/talk/0e3b7 @SammyK #zcoe18 rand() mt_rand() …in PHP 7.1 & above
103. joind.in/talk/0e3b7 @SammyK #zcoe18 mt_rand() Fixes bug in MT algorithm implementation Is a PRNG (totes predictable)
104. joind.in/talk/0e3b7 @SammyK #zcoe18 They’re totes samezies! rand() mt_rand() ===
105. joind.in/talk/0e3b7 @SammyK #zcoe18
106. joind.in/talk/0e3b7 @SammyK #zcoe18 rand() mt_rand() Both suffer from modulo bias &
107. joind.in/talk/0e3b7 @SammyK #zcoe18 Seeds aren’t impossible to predict
108. joind.in/talk/0e3b7 @SammyK #zcoe18 Entropy *Could be it’s own talk
109. joind.in/talk/0e3b7 @SammyK #zcoe18 A measure of how accurately we’re able to predict the next value in a sequence.* * oversimplification
110. joind.in/talk/0e3b7 @SammyK #zcoe18 High entropy harder to predict Low entropy easier to predict
111. joind.in/talk/0e3b7 @SammyK #zcoe18 High entropy harder to predict Good for random number generation
112. joind.in/talk/0e3b7 @SammyK #zcoe18 Cryptographically Pseudorandom Secure Number Generator
113. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG or…
114. joind.in/talk/0e3b7 @SammyK #zcoe18 “See Spring” or…
115. Unicorn Magical
116. Uses seeds that are really really really really ridiculously hard to guess
117. joind.in/talk/0e3b7 @SammyK #zcoe18 High Entropy wee!
118. joind.in/talk/0e3b7 @SammyK #zcoe18 impossible It’s values are to predict in practice 42 82 Suitable for use in cryptographic contexts.
119. mythical Where can we find this creature?
120. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG options in 5.x
121. joind.in/talk/0e3b7 @SammyK #zcoe18 openssl_random_pseudo_bytes() mcrypt_create_iv() /dev/urandom
122. joind.in/talk/0e3b7 @SammyK #zcoe18 openssl_random_pseudo_bytes() mcrypt_create_iv() /dev/urandom
123. joind.in/talk/0e3b7 @SammyK #zcoe18
124. joind.in/talk/0e3b7 @SammyK #zcoe18 TAKE_ to_live TAKE_ to_lie
125. joind.in/talk/0e3b7 @SammyK #zcoe18 TAKE_ to_lie 5.6.11
126. joind.in/talk/0e3b7 @SammyK #zcoe18 5.6.12 TAKE_ to_live
127. Fails open
128. joind.in/talk/0e3b7 @SammyK #zcoe18 FALSE Can return
129. joind.in/talk/0e3b7 @SammyK #zcoe18 empty string Can be
130. joind.in/talk/0e3b7 @SammyK #zcoe18 Still not done!
131. joind.in/talk/0e3b7 @SammyK #zcoe18 WRONG Easy to get
132. joind.in/talk/0e3b7 @SammyK #zcoe18 Worse It gets
133. joind.in/talk/0e3b7 @SammyK #zcoe18 Since the UNIX fork() system call duplicates the entire process state, a random number generator which does not take this issue into account will produce the same sequence of random numbers in both the parent and the child […], leading to cryptographic disaster… https://wiki.openssl.org/index.php/Random_fork-safety
134. joind.in/talk/0e3b7 @SammyK #zcoe18 OpenSSL’s be like 42 CSPRNG 82 82
135. joind.in/talk/0e3b7 @SammyK #zcoe18 OpenSSL cannot fix the fork-safety problem because its not in a position to do so. However, there are [solutions] available and they are listed below. https://wiki.openssl.org/index.php/Random_fork-safety
136. joind.in/talk/0e3b7 @SammyK #zcoe18 Don't use RAND_bytes https://wiki.openssl.org/index.php/Random_fork-safety
137. joind.in/talk/0e3b7 @SammyK #zcoe18 Instead, you can read directly from /dev/random, /dev/urandom or /dev/srandom; or use CryptGenRandom on Windows systems. https://wiki.openssl.org/index.php/Random_fork-safety
138. joind.in/talk/0e3b7 @SammyK #zcoe18 Status update! v1.1.1 (2018-09-11)
139. joind.in/talk/0e3b7 @SammyK #zcoe18 mcrypt_create_iv() /dev/urandom openssl_random_pseudo_bytes()
140. Fails open
141. joind.in/talk/0e3b7 @SammyK #zcoe18
142. joind.in/talk/0e3b7 @SammyK #zcoe18
143. joind.in/talk/0e3b7 @SammyK #zcoe18
144. joind.in/talk/0e3b7 @SammyK #zcoe18 /dev/urandom openssl_random_pseudo_bytes() mcrypt_create_iv()
145. joind.in/talk/0e3b7 @SammyK #zcoe18 open_basedir=/foo/dir
146. joind.in/talk/0e3b7 @SammyK #zcoe18 openssl_random_pseudo_bytes() mcrypt_create_iv() /dev/urandom
147. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG New goodness 7
148. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG random_int() random_bytes()
149. random_int(0,99) 6,17,6,9,17,53,58,98,46,44,62,9,76,65,46,21,42,5,65,34,11,96,85,7,46,89,98,9,9, 80,8,76,87,18,24,68,16,61,27,39,30,32,4,83,83,23,96,27,13,47,6,99,16,40,2,75,27 ,3,79,68,75,60,50,70,63,17,75,29,79,57,9,48,18,86,95,25,40,52,20,86,6,48,94,27, 76,14,9,27,62,14,68,58,12,18,63,19,84,47,7,13,63,28,66,55,2,75,44,92,11,85,51,1 7,42,57,22,4,53,7,3,76,48,55,95,7,45,33,87,36,11,17,66,6,46,87,57,48,22,31,65,5 ,26,10,47,82,97,74,25,32,63,60,29,53,13,24,56,54,52,86,67,4,94,35,48,73,35,45,2 4,74,74,83,49,70,41,49,20,60,29,49,30,35,38,63,4,86,72,97,26,22,36,95,59,94,24, 89,73,46,14,73,51,93,93,39,13,80,9,30,24,20,30,63,20,64,97,29,7,2,82,96,42,61,5 3,28,49,12,90,71,58,72,63,49,32,69,76,50,62,88,31,26,72,79,19,15,3,39,27,80,16, 65,62,53,82,59,23,85,95,41,68,86,3,92,76,91,88,12,20,96,14,35,50,94,24,23,44,55 ,78,65,81,7,1,86,32,58,46,97,43,78,9,51,1,6,79,73,49,13,40,21,90,14,9,70,95,88, 37,85,14,7,29,42,55,81,46,39,41,45,81,11,93,26,89,4,98,35,30,36,74,97,18,85,97, 23,52,64,88,20,89,12,25,19,21,21,50,60,50,43,84,1,52,5,19,2,86,38,51,48,30,55,9 0,93,97,52,84,29,58,96,78,37,24,14,72,81,9,82,26,83,83,17,35,15,9,87,95,51,71,4 8,9,45,13,61,98,3,18,96,99,28,74,47,58,71,89,68,57,51,86,90,38,21,72,72,30,22,1 3,88,25,48,45,62,59,81,32,10,54,82,60,90,17,98,41,73,98,60,22,99,66,32,41,82,62 ,91,3,85,91,21,17,98,19,48,50,24,67,3,14,62,55,35,99,95,83,76,12,51,77,61,24,24 ,60,15,31,47,24,27,97,98,70,6,24,25,20,23,67,72,55,47,19,53,50,38,22,76,37,63,8 2,67,52,3,75,84,84,71,49,79,26,89,11,77,55,92,32,81,38,23,54,9,40,80,75,20,7,58 ,37,72,75,59,46,32,41,82,90,72,59,5,42,2,94,44,44,4,15,37,29,24,10,51,18,8,42,5 6,9,68,31,99,7,77,59,8,74,80,11,15,93,81,5,72,44,49,39,25,4,18,98,0,93,42,78,36 ,57,47,16,49,2,85,6,31,17,81,10,54,40,95,68,31,80,29,41,86,32,9,58,96,62,79,25, 6,45,56,54,0,61,74,90,12,34,11,56,3,41,39,84,32,30,42,81,36,43,5,
150. joind.in/talk/0e3b7 @SammyK #zcoe18 bin2hex(random_bytes(16)) f7f5289027cb6c5116d 2d3cc78e5819c
151. Fails Closed
152. joind.in/talk/0e3b7 @SammyK #zcoe18 You’re not strong until you’re crypto-strong!
153. CSPRNG under the hood
155. joind.in/talk/0e3b7 @SammyK #zcoe18 On Windows: CryptGenRandom On BSD: arc4random_buf() On Linux: getrandom(2) syscall Read directly from /dev/urandom
156. joind.in/talk/0e3b7 @SammyK #zcoe18 /dev/urandom So what is this thing?
157. /dev/urandom Gathers environmental noise from the system like… …device drivers, inter-keyboard timings, inter-interrupt timings from some interrupts, and other events which are both (a) non-deterministic and (b) hard for an outside observer to measure. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/random.c
158. joind.in/talk/0e3b7 @SammyK #zcoe18 CSPRNG random_bytes() random_int() 7 /dev/urandom Powered by
159. joind.in/talk/0e3b7 @SammyK #zcoe18 Still on 5.x? paragonie/random_compat Polyfill for PHP 7 CSPRNG
160. joind.in/talk/0e3b7 @SammyK #zcoe18 http://php.net/supported-versions.php 5.6 EOL in 75 days
161. joind.in/talk/0e3b7 @SammyK #zcoe18 http://php.net/supported-versions.php 7.0 EOL in 47 days
162. joind.in/talk/0e3b7 @SammyK #zcoe18 FAQ’s
163. joind.in/talk/0e3b7 @SammyK #zcoe18 Benchmarks* * are lies
164. joind.in/talk/0e3b7 @SammyK #zcoe18 If random_bytes() random_int() are… …why not update mt_rand()
165. joind.in/talk/0e3b7 @SammyK #zcoe18
166. joind.in/talk/0e3b7 @SammyK #zcoe18
167. joind.in/talk/0e3b7 @SammyK #zcoe18 TL;DR Never use LCG, MT, or any other PRNG in cryptographic contexts Only use a CSPRNG like /dev/urandom for crypto Use random_bytes() & random_int() in PHP (or install paragonie/random_compat)
168. joind.in/talk/0e3b7 @SammyK #zcoe18 More Resources
169. joind.in/talk/0e3b7 @SammyK #zcoe18 Recommendation for the Entropy Sources Used for Random Bit Generation Final Draft - NIST SP 800-90B https://csrc.nist.gov/publications/detail/sp/800-90b/final
170. joind.in/talk/0e3b7 @SammyK #zcoe18 New & improved man pages for /dev/urandom http://man7.org/linux/man-pages/man7/random.7.html
171. joind.in/talk/0e3b7 @SammyK #zcoe18 Myths about /dev/urandom Thomas Hühn https://www.2uo.de/myths-about-urandom/ With pretty pictures!
172. joind.in/talk/0e3b7 @SammyK #zcoe18 Cracking Random Number Generators Three-part blog post series James Roper https://jazzy.id.au/2010/09/20/cracking_random_number_generators_part_1.html
173. joind.in/talk/0e3b7 @SammyK #zcoe18 How I Met Your Girlfriend DEF CON 18 Samy Kamkar https://www.youtube.com/watch?v=fWk_rMQiDGc
174. joind.in/talk/0e3b7 @SammyK #zcoe18 Weak RNG in PHP session ID generation leads to session hijacking Andreas Bogk http://seclists.org/fulldisclosure/2010/Mar/519
175. joind.in/talk/0e3b7 @SammyK #zcoe18 Sammy Kaye Powers Thanks! /talk/0e3b7 @SammyK SammyK.me Host of @PHPRoundtable