Possible fix of travis build.

Telegram/SourceFiles/_other/packer.h

@@ -17,6 +17,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include <zlib.h>
 
+extern "C" {
 #include <openssl/bn.h>
 #include <openssl/rsa.h>
 #include <openssl/pem.h>
@@ -24,6 +25,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <openssl/err.h>
 #include <openssl/aes.h>
 #include <openssl/evp.h>
+} // extern "C"
 
 #ifdef Q_OS_WIN // use Lzma SDK for win
 #include <LzmaLib.h>
@@ -34,6 +36,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <string>
 #include <iostream>
 #include <exception>
+
 using std::string;
 using std::wstring;
 using std::cout;

Telegram/SourceFiles/base/openssl_help.h

@@ -7,12 +7,15 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
+#include "base/bytes.h"
+
+extern "C" {
 #include <openssl/bn.h>
 #include <openssl/sha.h>
 #include <openssl/rand.h>
 #include <openssl/aes.h>
 #include <openssl/crypto.h>
-#include "base/bytes.h"
+} // extern "C"
 
 namespace openssl {
 

Telegram/SourceFiles/core/update_checker.cpp

@@ -18,10 +18,12 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "core/click_handler_types.h"
 #include "settings/settings_widget.h"
 
+extern "C" {
 #include <openssl/rsa.h>
 #include <openssl/pem.h>
 #include <openssl/bio.h>
 #include <openssl/err.h>
+} // extern "C"
 
 #ifdef Q_OS_WIN // use Lzma SDK for win
 #include <LzmaLib.h>

Telegram/SourceFiles/core/utils.cpp

@@ -11,6 +11,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "application.h"
 #include "platform/platform_specific.h"
 
+extern "C" {
 #include <openssl/crypto.h>
 #include <openssl/sha.h>
 #include <openssl/err.h>
@@ -19,8 +20,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <openssl/conf.h>
 #include <openssl/ssl.h>
 #include <openssl/rand.h>
-
-extern "C" {
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 } // extern "C"

Telegram/SourceFiles/mtproto/auth_key.cpp

@@ -7,8 +7,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #include "mtproto/auth_key.h"
 
+extern "C" {
 #include <openssl/aes.h>
 #include <openssl/modes.h>
+} // extern "C"
 
 namespace MTP {
 

Telegram/SourceFiles/mtproto/connection.cpp

@@ -18,12 +18,15 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lang/lang_keys.h"
 #include "base/openssl_help.h"
 #include "base/qthelp_url.h"
+
+extern "C" {
 #include <openssl/bn.h>
 #include <openssl/err.h>
 #include <openssl/aes.h>
 #include <openssl/sha.h>
 #include <openssl/md5.h>
 #include <openssl/rand.h>
+} // extern "C"
 
 namespace MTP {
 namespace internal {

Telegram/SourceFiles/mtproto/connection_tcp.cpp

@@ -10,7 +10,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/bytes.h"
 #include "base/openssl_help.h"
 #include "base/qthelp_url.h"
+
+extern "C" {
 #include <openssl/aes.h>
+} // extern "C"
 
 namespace MTP {
 namespace internal {

Telegram/SourceFiles/mtproto/rsa_public_key.cpp

@@ -8,10 +8,13 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mtproto/rsa_public_key.h"
 
 #include "base/openssl_help.h"
+
+extern "C" {
 #include <openssl/rsa.h>
 #include <openssl/pem.h>
 #include <openssl/bio.h>
 #include <openssl/err.h>
+} // extern "C"
 
 namespace MTP {
 namespace internal {

Telegram/SourceFiles/mtproto/special_config_request.cpp

@@ -11,7 +11,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mtproto/dc_options.h"
 #include "mtproto/auth_key.h"
 #include "base/openssl_help.h"
+
+extern "C" {
 #include <openssl/aes.h>
+} // extern "C"
 
 namespace MTP {
 namespace {

Telegram/SourceFiles/storage/localstorage.cpp

@@ -30,7 +30,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_session.h"
 #include "history/history.h"
 
+extern "C" {
 #include <openssl/evp.h>
+} // extern "C"
 
 namespace Local {
 namespace {