X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fcrypto.h;h=9fc4156c82a3aaf0e65dedefb453d3ece318242c;hb=6debc6c79ba385d35f646e0958f84ace5b8f4b4d;hp=cd3654fec4849805c004e86eb6fd68c7729c5b6e;hpb=0acdce222ff21c84cafc82c137e3d1e107a66fd9;p=tinc

diff --git a/src/crypto.h b/src/crypto.h
index cd3654fe..9fc4156c 100644
--- a/src/crypto.h
+++ b/src/crypto.h
@@ -1,3 +1,8 @@
+#ifndef TINC_CRYPTO_H
+#define TINC_CRYPTO_H
+
+#include "system.h"
+
 /*
     crypto.h -- header for crypto.c
     Copyright (C) 2007-2013 Guus Sliepen <guus@tinc-vpn.org>
@@ -17,11 +22,23 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#ifndef __TINC_CRYPTO_H__
-#define __TINC_CRYPTO_H__
+extern void crypto_init(void);
+extern void crypto_exit(void);
+extern uint64_t xoshiro(void);
+extern void prng_init(void);
+extern void prng_randomize(void *buf, size_t buflen);
+extern void randomize(void *buf, size_t buflen);
+
+static inline uint32_t prng(uint32_t limit) {
+	uint64_t bins = UINT64_MAX / limit;
+	uint64_t reject_after = bins * limit;
+	uint64_t value;
+
+	do {
+		value = xoshiro();
+	} while(value >= reject_after);
 
-extern void crypto_init();
-extern void crypto_exit();
-extern void randomize(void *, size_t);
+	return value / bins;
+}
 
 #endif