1 files changed, 51 insertions, 0 deletions
diff --git a/extract_decoded_executable/rng.h b/extract_decoded_executable/rng.h
new file mode 100644
index 0000000..93fd317
--- /dev/null
+++ b/extract_decoded_executable/rng.h
@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+struct rngstate{
+	uint64_t state[16];
+	int idx;
+};
+
+static struct rngstate global_rng_state;
+
+void init_rng(){
+	uint64_t seed_val = (uint64_t)SEED_VAL;
+	size_t c_idx = 0;
+	for ( ; c_idx < 16; c_idx++ ){
+		seed_val = seed_val * 0x13371337;
+		seed_val = seed_val ^ (seed_val >> 16);
+		global_rng_state.state[c_idx] = seed_val;
+	}
+	return;
+}
+
+uint64_t get_rng_output(){
+	int c_idx = global_rng_state.idx;
+	const uint64_t next_state = global_rng_state.state[c_idx++];
+	uint64_t use_state = global_rng_state.state[c_idx &= 15];
+	use_state ^= use_state << 31;
+	use_state ^= use_state >> 16;
+	use_state ^= next_state ^ (next_state >> 31);
+	global_rng_state.state[c_idx] = use_state;
+	global_rng_state.idx = c_idx;
+	return use_state * 0x1337;
+}
+
+unsigned int get_random_int( unsigned int min, unsigned int max ){
+	if ( min >= max )
+		return min;
+	uint64_t nmax = 0xffffffffffffffff;
+	uint64_t ncount = (max - min) + 1;
+	uint64_t upper_limit = nmax - (nmax % ncount);
+	uint64_t rand_int = get_rng_output();
+	if ( rand_int > upper_limit ){
+		while ( rand_int > upper_limit )
+			rand_int = get_rng_output();
+	}
+	return (unsigned int)(rand_int % max) + min;
+}