Add Windows support

.github/workflows/main.yml

@@ -62,3 +62,15 @@ jobs:
       run: |
         cmake -Dmake_tests=ON .
         make
+
+  build-windows:
+    name: Build for Windows using CMake
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build tinydtls
+      run: |
+        cmake -G "Unix Makefiles" .
+        make
+

.gitignore

@@ -51,6 +51,7 @@ dtls_config.h
 *.cooja
 *.econotag
 *.eval-adf7xxxmb4z
+*.exe
 *.exp5438
 *.iris
 *.mbxxx
@@ -70,3 +71,23 @@ dtls_config.h
 CMakeCache.txt
 cmake_install.cmake
 CMakeFiles
+
+# Windows build files
+*.dll
+
+# Visual Studio Build Files
+*.VC.db*
+.vs
+*.obj
+*.tlog
+*.log
+*.recipe
+*.vcxproj
+*.sln
+*.pdb
+*.vcxproj.user
+*.vcxproj.filters
+*.vcxproj.FileListAbsolute.txt
+tinydtls.dir
+Debug
+Release

CMakeLists.txt

@@ -31,7 +31,7 @@ option(make_tests "Make test programs and examples" OFF)
 if(NOT PLATFORM)
    # PLATFORM seems to be not used
    set(PLATFORM "posix" CACHE STRING "Choose platform." FORCE)
-   set_property(CACHE PLATFORM PROPERTY STRINGS "contiki" "espidf" "posix" "riot" "zephyr")
+   set_property(CACHE PLATFORM PROPERTY STRINGS "contiki" "espidf" "posix" "riot" "zephyr" "windows")
 endif()
 
 set(PACKAGE_NAME "tinydtls")
@@ -64,8 +64,11 @@ target_sources(tinydtls PRIVATE
 target_include_directories(tinydtls PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_BINARY_DIR})
 target_compile_definitions(tinydtls PUBLIC DTLSv12 WITH_SHA256 SHA2_USE_INTTYPES_H DTLS_CHECK_CONTENTTYPE)
 
-if(NOT ZEPHYR_BASE)
-   target_compile_options(tinydtls PRIVATE -fPIC -pedantic -std=c99 -Wall -Wextra -Wformat-security -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wunused)
+if(CMAKE_GENERATOR MATCHES "Visual Studio")
+    option(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS "Export all symbols when compiling to a .dll" ON)
+    target_compile_options(tinydtls PRIVATE -Wall)
+elseif(NOT ZEPHYR_BASE)
+    target_compile_options(tinydtls PRIVATE -fPIC -pedantic -std=c99 -Wall -Wextra -Wformat-security -Winline -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wpointer-arith -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wunused)
 endif()
 
 set_target_properties(tinydtls PROPERTIES VERSION ${PACKAGE_VERSION} SOVERSION ${SOVERSION})

README.md

@@ -18,6 +18,12 @@ C99. The following components are available:
 
 # BUILDING
 
+tinydtls supports multiple platforms, including both Real-time
+and general-purpose Operating Systems. Below you find build instructions for
+all supported environments.
+
+## POSIX-oriented Operating Systems
+
 When using the code from the git
 [repository](https://github.com/eclipse/tinydtls) at GitHub, invoke
 
@@ -68,6 +74,39 @@ Available options:
 | DTLS_ECC | enable/disable ECDHE_ECDSA cipher suites | ON |
 | DTLS_PSK | enable/disable PSK cipher suites | ON |
 
+## Windows
+
+Using CMake, you can also build on and for Windows using either GCC or Visual
+Studio.
+Note, however, that the `make_tests` option is currently not supported when
+compiling with Visual Studio, as parts of the tests rely on POSIX APIs.
+
+For Visual Studio, you can apply the CMake instructions outlined above from the
+command line or use the CMake GUI application.
+
+In order to be able to use GCC, you need to specify a different generator than
+the default.
+For instance, you can use the `Unix Makefiles` generator, which creates a
+Makefile for controlling the build process using GCC.
+The example below leads to the output of a shared library file
+`libtinydtls.dll`.
+
+```
+cmake -G "Unix Makefiles" -DBUILD_SHARED_LIBS=ON .
+make
+```
+
+Using MinGW64, you can also cross compile from a POSIX-oriented
+platform for Windows using Autotools by providing a corresponding `--host`
+argument:
+
+```
+./autogen.sh
+./configure --host x86_64-w64-mingw32
+make
+mv libtinydtls.so libtinydtls.dll # Apply Windows file extension
+```
+
 # License
 
 Copyright (c) 2011–2022 Olaf Bergmann (TZI) and others.

dtls.c

@@ -213,7 +213,7 @@ static inline void free_context(dtls_context_t *context) {
 }
 #endif /* RIOT_VERSION */
 
-#ifdef WITH_POSIX
+#if defined(WITH_POSIX) || defined(IS_WINDOWS)
 
 static inline dtls_context_t *
 malloc_context(void) {
@@ -1610,9 +1610,11 @@ dtls_0_send_hello_verify_request(dtls_context_t *ctx,
 			     dtls_ephemeral_peer_t *ephemeral_peer,
 			     uint8 *data, size_t data_length)
 {
-  uint8 buf[DTLS_RH_LENGTH + DTLS_HS_LENGTH + data_length];
+  uint8 buf[DTLS_RH_LENGTH + DTLS_HS_LENGTH + DTLS_HV_LENGTH + DTLS_COOKIE_LENGTH];
   uint8 *p = dtls_set_record_header(DTLS_CT_HANDSHAKE, 0, &(ephemeral_peer->rseq), buf);
 
+  assert(data_length == DTLS_HV_LENGTH + DTLS_COOKIE_LENGTH);
+
   /* Signal DTLS version 1.0 in the record layer of ClientHello and
    * HelloVerifyRequest handshake messages according to Section 4.2.1
    * of RFC 6347.

dtls.h

@@ -341,8 +341,16 @@ void dtls_check_retransmit(dtls_context_t *context, clock_time_t *next);
 #define DTLS_CT_HANDSHAKE          22
 #define DTLS_CT_APPLICATION_DATA   23
 
+#ifdef __GNUC__
+#define PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__))
+#elif defined(_MSC_VER)
+#define PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop))
+#else
+#error "Structure packing is not available for the used compiler."
+#endif
+
 /** Generic header structure of the DTLS record layer. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint8 content_type;		/**< content type of the included message */
   uint16 version;		/**< Protocol version */
   uint16 epoch;		        /**< counter for cipher state changes */
@@ -371,7 +379,7 @@ typedef struct __attribute__((__packed__)) {
 #define DTLS_HT_NO_OPTIONAL_MESSAGE        -1
 
 /** Header structure for the DTLS handshake protocol. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint8 msg_type; /**< Type of handshake message  (one of DTLS_HT_) */
   uint24 length;  /**< length of this message */
   uint16 message_seq; 	/**< Message sequence number */
@@ -381,7 +389,7 @@ typedef struct __attribute__((__packed__)) {
 } dtls_handshake_header_t;
 
 /** Structure of the Client Hello message. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint16 version;	  /**< Client version */
   uint32 gmt_random;	  /**< GMT time of the random byte creation */
   unsigned char random[28];	/**< Client random bytes */
@@ -392,7 +400,7 @@ typedef struct __attribute__((__packed__)) {
 } dtls_client_hello_t;
 
 /** Structure of the Hello Verify Request. */
-typedef struct __attribute__((__packed__)) {
+PACK(typedef struct) {
   uint16 version;		/**< Server version */
   uint8 cookie_length;	/**< Length of the included cookie */
   uint8 cookie[];		/**< up to 32 bytes making up the cookie */

dtls_debug.c

@@ -222,12 +222,13 @@ dsrv_print_addr(const session_t *addr, char *buf, size_t len) {
 
 #endif /* WITH_CONTIKI */
 
-#ifdef RIOT_VERSION
+#if defined(RIOT_VERSION) || defined(IS_WINDOWS)
   /* FIXME: Switch to RIOT own DEBUG lines */
+  /* TODO: Check if inet_ntop can be used on Windows */
   (void) addr;
   (void) buf;
   (void) len;
-#endif /* RIOT_VERSION */
+#endif /* RIOT_VERSION || IS_WINDOWS */
 
 #ifdef WITH_POSIX
   /* TODO: output addresses manually */
@@ -240,7 +241,7 @@ dsrv_print_addr(const session_t *addr, char *buf, size_t len) {
 
 #endif /* NDEBUG */
 
-#ifndef WITH_CONTIKI
+#if !defined(WITH_CONTIKI) && !defined(_MSC_VER)
 void
 dsrv_log(log_t level, const char *format, ...) {
   static char timebuf[32];

dtls_debug.h

@@ -78,11 +78,11 @@ void dtls_set_log_level(log_t level);
  * level is below or equal to the log level that set by
  * set_log_level(). */
 #ifdef HAVE_VPRINTF
-#if (defined(__GNUC__))
+#if (defined(__GNUC__) && !defined(__MINGW32__))
 void dsrv_log(log_t level, const char *format, ...) __attribute__ ((format(printf, 2, 3)));
-#else /* !__GNUC__ */
+#else /* !__GNUC__ && !__MINGW32__ */
 void dsrv_log(log_t level, const char *format, ...);
-#endif /* !__GNUC__ */
+#endif /* !__GNUC__ && !__MINGW32__ */
 #else
 #define dsrv_log(level, format, ...) PRINTF(format, ##__VA_ARGS__)
 #endif

dtls_mutex.h

@@ -42,10 +42,12 @@ typedef int dtls_mutex_t;
 #define dtls_mutex_trylock(a) *(a) = 1
 #define dtls_mutex_unlock(a) *(a) = 0
 
-#elif defined(WITH_ZEPHYR)
+#elif defined(WITH_ZEPHYR) || defined(IS_WINDOWS)
 
 /* zephyr supports mutex, but this port doesn't use it */
 
+// TODO: Add Windows compatible mutex definitions
+
 typedef int dtls_mutex_t;
 #define DTLS_MUTEX_INITIALIZER 0
 #define dtls_mutex_lock(a) *(a) = 1
@@ -53,7 +55,7 @@ typedef int dtls_mutex_t;
 #define dtls_mutex_unlock(a) *(a) = 0
 
 
-#else /* ! RIOT_VERSION && ! WITH_CONTIKI && ! WITH_ZEPHYR */
+#else /* ! RIOT_VERSION && ! WITH_CONTIKI && ! WITH_ZEPHYR && ! IS_WINDOWS */
 
 #include <pthread.h>
 
@@ -63,6 +65,6 @@ typedef pthread_mutex_t dtls_mutex_t;
 #define dtls_mutex_trylock(a) pthread_mutex_trylock(a)
 #define dtls_mutex_unlock(a) pthread_mutex_unlock(a)
 
-#endif /* ! RIOT_VERSION && ! WITH_CONTIKI */
+#endif /* ! RIOT_VERSION && ! WITH_CONTIKI && ! IS_WINDOWS */
 
 #endif /* _DTLS_MUTEX_H_ */

dtls_prng.c

@@ -30,6 +30,9 @@
 #elif defined (WITH_ZEPHYR)
 #include "platform-specific/dtls_prng_zephyr.c"
 
+#elif defined (IS_WINDOWS)
+#include "platform-specific/dtls_prng_win.c"
+
 #elif defined (WITH_POSIX)
 #include "platform-specific/dtls_prng_posix.c"
 

dtls_time.c

@@ -22,6 +22,11 @@
 #include "tinydtls.h"
 #include "dtls_time.h"
 
+#ifdef _MSC_VER
+#include <time.h>
+#include <windows.h>
+#endif
+
 #ifdef WITH_CONTIKI
 clock_time_t dtls_clock_offset;
 
@@ -64,7 +69,7 @@ dtls_ticks(dtls_tick_t *t) {
   *t = k_uptime_get();
 }
 
-#elif defined(WITH_POSIX)
+#elif defined(WITH_POSIX) || defined(IS_WINDOWS)
 
 time_t dtls_clock_offset;
 
@@ -88,6 +93,11 @@ void dtls_ticks(dtls_tick_t *t) {
   gettimeofday(&tv, NULL);
   *t = (tv.tv_sec - dtls_clock_offset) * DTLS_TICKS_PER_SECOND 
     + (tv.tv_usec * DTLS_TICKS_PER_SECOND / 1000000);
+#elif defined(_MSC_VER)
+  SYSTEMTIME current_time;
+  GetSystemTime(&current_time);
+  *t = (current_time.wSecond - dtls_clock_offset) * DTLS_TICKS_PER_SECOND 
+    + (current_time.wMilliseconds * DTLS_TICKS_PER_SECOND / 1000);
 #else
 #error "clock not implemented"
 #endif

ecc/ecc.c

@@ -39,6 +39,7 @@
 //big number functions
 #include "ecc.h"
 #include <string.h>
+#include <assert.h>
 
 static uint32_t add( const uint32_t *x, const uint32_t *y, uint32_t *result, uint8_t length){
 	uint64_t d = 0; //carry
@@ -157,7 +158,8 @@ static int fieldSub(const uint32_t *x, const uint32_t *y, const uint32_t *modulu
 //finite Field multiplication
 //32bit * 32bit = 64bit
 static int fieldMult(const uint32_t *x, const uint32_t *y, uint32_t *result, uint8_t length){
-	uint32_t temp[length * 2];
+	uint32_t temp[(arrayLength + 1) * 2];
+	assert(length <= arrayLength + 1);
 	setZero(temp, length * 2);
 	setZero(result, length * 2);
 	uint8_t k, n;

platform-specific/dtls_prng_win.c

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2022 Jan Romann and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
+ *
+ * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ *******************************************************************************/
+
+#include "tinydtls.h"
+#include "dtls_prng.h"
+#include "dtls_debug.h"
+
+#define _CRT_RAND_S
+
+#include <stdlib.h>
+
+#if defined(__MINGW32__)
+/** Missing function declaration for rand_s under MingW. */
+__declspec(dllimport) int __cdecl rand_s(unsigned int*);
+#endif
+
+/**
+ * Fills @p buf with @p len random bytes. Returns a non-zero
+ * value on error.
+ */
+int
+dtls_prng(unsigned char *buf, size_t len) {
+  errno_t err;
+  unsigned int number;
+  size_t klen = len;
+  while (len--) {
+    err = rand_s(&number);
+    if (err != 0) {
+      dtls_emerg("PRNG failed\n");
+      return err;
+    }
+    *buf++ = number & 0xFF;
+  }
+  return klen;
+}
+
+void
+dtls_prng_init(unsigned seed) {
+  srand(seed);
+}

session.h

@@ -1,6 +1,6 @@
 /*******************************************************************************
  *
- * Copyright (c) 2011-2019 Olaf Bergmann (TZI) and others.
+ * Copyright (c) 2011-2022 Olaf Bergmann (TZI) and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
@@ -64,7 +64,11 @@ typedef struct {
 #undef read
 typedef unsigned char uint8_t;
 
-#else /* ! WITH_ZEPHYR && ! WITH_LWIP */
+#elif defined(IS_WINDOWS)
+#include <winsock2.h>
+#include <ws2tcpip.h>
+
+#else /* ! WITH_ZEPHYR && ! WITH_LWIP && ! IS_WINDOWS */
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>

sha2/sha2.h

@@ -48,6 +48,16 @@ extern "C" {
 #include <sys/types.h>
 #include "tinydtls.h"
 
+#ifdef IS_WINDOWS
+#include <stdint.h>
+
+typedef uint8_t u_int8_t;
+typedef uint16_t u_int16_t;
+typedef uint32_t u_int32_t;
+typedef uint64_t u_int64_t;
+
+#endif
+
 #ifdef SHA2_USE_INTTYPES_H
 
 #include <inttypes.h>

tests/dtls-server.c

@@ -7,19 +7,27 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
-#include <netinet/in.h>
 #include <sys/types.h>
-#include <sys/socket.h>
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif /* HAVE_SYS_TIME_H */
-#include <netdb.h>
 #include <signal.h>
 
 #include "tinydtls.h" 
 #include "dtls.h" 
 #include "dtls_debug.h"
 
+#ifdef IS_WINDOWS
+#include <winsock2.h>
+#pragma comment(lib, "Ws2_32.lib")
+#define MSG_DONTWAIT 0
+#define MSG_TRUNC 0
+#else /* ! IS_WINDOWS */
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#endif /* ! IS_WINDOWS */
+
 #define DEFAULT_PORT 20220
 
 static dtls_context_t *the_context = NULL;
@@ -277,7 +285,9 @@ main(int argc, char **argv) {
   int on = 1;
   int off = 0;
   struct sockaddr_in6 listen_addr;
+#ifndef IS_WINDOWS
   struct sigaction sa;
+#endif /* ! IS_WINDOWS */
   uint16_t port = htons(DEFAULT_PORT);
 
   memset(&listen_addr, 0, sizeof(struct sockaddr_in6));
@@ -357,6 +367,7 @@ main(int argc, char **argv) {
 
   dtls_init();
 
+#ifndef IS_WINDOWS
   memset (&sa, 0, sizeof(sa));
   sigemptyset(&sa.sa_mask);
   sa.sa_handler = dtls_handle_signal;
@@ -366,6 +377,7 @@ main(int argc, char **argv) {
   /* So we do not exit on a SIGPIPE */
   sa.sa_handler = SIG_IGN;
   sigaction (SIGPIPE, &sa, NULL);
+#endif /* ! IS_WINDOWS */
 
   the_context = dtls_new_context(&fd);
 

tinydtls.h

@@ -32,12 +32,18 @@
 #include "platform-specific/platform.h"
 #endif /* CONTIKI */
 
+#if defined(_WIN32) || defined(_WIN64)
+#define IS_WINDOWS 1
+#endif
+
 #ifndef CONTIKI
 #ifndef RIOT_VERSION
+#ifndef IS_WINDOWS
 #ifndef WITH_POSIX
 /* TODO: To remove in a future */
 #define WITH_POSIX 1
 #endif /* WITH_POSIX */
+#endif /* IS_WINDOWS */
 #include "dtls_config.h"
 #endif /* RIOT_VERSION */
 #endif /* CONTIKI */