From b4709429ed88563982412a5a027b92143c37e268 Mon Sep 17 00:00:00 2001
From: Nakidai <nakidai@disroot.org>
Date: Thu, 31 Jul 2025 17:12:27 +0300
Subject: Add files

---
 common.h | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 common.h

(limited to 'common.h')

diff --git a/common.h b/common.h
new file mode 100644
index 0000000..9bb5912
--- /dev/null
+++ b/common.h
@@ -0,0 +1,74 @@
+/* common (not config, need code patch after change) */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+#include <time.h>
+#include <net/if.h>
+#include <fcntl.h>
+
+#include <linux/if_tun.h>
+
+#include "shorttypes.h"
+#include "sponge-bob.h"
+
+#define ERRDIE(a, b) if ((a) == -1) perror((b)), exit(1)
+
+#define NONCE_SZ 16
+#define HMAC_SZ  16
+
+u8  key[32];
+u32 prng_state[14];
+
+
+static void send_pkt
+(s32 skt, void *buf, u16 sz, struct sockaddr_storage *addr){
+	ssize_t res;
+	u8 *nonce, *tag;
+
+	/* nonce, tag */
+	nonce = (u8*)buf + sz;
+	tag = nonce + NONCE_SZ;
+	duplex257_prng_rand16(prng_state, nonce);
+
+	/* encrypt */
+	duplex257_ae_encrypt(key, nonce, tag, buf, sz);
+	sz += NONCE_SZ + HMAC_SZ;
+
+	/* send */
+	res = sendto(skt, buf, sz, 0,(struct sockaddr*)addr, sizeof(*addr));
+	ERRDIE(res, "sendto");
+	return;
+}
+
+static s32 recv_pkt
+(s32 skt, void *buf, u16 sz, struct sockaddr_storage *addr){
+	socklen_t skl;
+	s32 res;
+	u8 *nonce, *rtag;
+	u8 tag[HMAC_SZ];
+
+	/* recv */
+	skl = sizeof(*addr);
+	res = recvfrom(skt, buf, sz, 0, (struct sockaddr*)addr, &skl);
+	ERRDIE(res, "recvfrom");
+
+	/* nonce, recieved tag */
+	rtag = buf + res - HMAC_SZ;
+	nonce  = rtag - NONCE_SZ;
+
+	/* decrypt */
+	res -= NONCE_SZ + HMAC_SZ;
+	duplex257_ae_decrypt(key, nonce, tag, buf, res);
+	if (0 != memcmp(tag, rtag, HMAC_SZ)) return -1;
+
+	return res;
+}
+
-- 
cgit 1.4.1