From b2aa636bfee0c4a7f607eaad06803cd7c42d8214 Mon Sep 17 00:00:00 2001
From: Benedict <benedict@0xb8000.de>
Date: Thu, 11 Aug 2016 18:56:21 +0200
Subject: set3, challenge 22 completed

---
 lib/lib3.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'lib/lib3.c')

diff --git a/lib/lib3.c b/lib/lib3.c
index 43f3ec6..adea72e 100644
--- a/lib/lib3.c
+++ b/lib/lib3.c
@@ -129,3 +129,35 @@ int mt_19937()
 
 	return (y & 0xFFFFFFFF);
 }
+
+int mt_19937_timestamp_orcale()
+{
+	sleep(random_number_between(40,1000));
+
+	unsigned int seed = time(NULL);
+	printf("timestamp orcale seed: %u\n", seed);
+	mt_19937_seed(seed);
+
+	sleep(random_number_between(40,1000));
+
+	return  mt_19937();
+}
+/***
+  * is there a more clever way to do this than brute force?
+  *
+  **/
+void mt_19937_brute_force_timestamp()
+{
+	unsigned int start = time(NULL);
+	int rnd = mt_19937_timestamp_orcale();
+	unsigned int stop = time(NULL);
+	unsigned int i;
+	// try every seed between start and stop
+	for(i=start;start<=stop;i++) {
+		mt_19937_seed(i);
+		if (rnd == mt_19937()) {
+			printf("found seed: %u\n", i);
+			break;
+		}
+	}
+}
-- 
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