我目前正在开发一个 C++ IMAP 库，这样我就可以改进一些公认的生锈的 C++ 技能。我想让这个库尽可能便携，这样我就可以跨操作系统使用它，如果我觉得疯狂，甚至可以在移动设备上使用它。为此，我做了一些研究并决定使用 Boost 的 Asio 库。
我能够让 Boost 自行在我的项目中构建和运行。我对 google.com 做了一个简单的 HTTP GET。不幸的是，我需要能够使用 TLS 进行通信，并且在尝试使用 Asio 的 SSL 功能时遇到了问题。
我使用默认设置从源代码构建了 Boost 和 OpenSSL(所以一切都在/usr/local 中)。我也在使用 CMAKE 来构建我的项目。下面是我的 CMAKE 文件:
cmake_minimum_required(VERSION 3.2)
project(IMAP)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
message(WARNING "Starting CMAKE...")
set(SOURCE_FILES main.cpp)
add_executable(IMAP ${SOURCE_FILES})
find_package(Boost COMPONENTS system thread regex REQUIRED)
message(WARNING "Boost_INCLUDE_DIR: ${Boost_INCLUDE_DIR}")
message(WARNING "Boost_LIBRARIES: ${Boost_LIBRARIES}")
message(WARNING "Boost_VERSION: ${Boost_VERSION}")
include_directories(${Boost_INCLUDE_DIR})
target_link_libraries(IMAP ${Boost_LIBRARIES})
find_package(OpenSSL REQUIRED)
message(WARNING "OpenSSL_VERSION: ${OPENSSL_VERSION}")
message(WARNING "OpenSSL_INCLUDE_DIR: ${OPENSSL_INCLUDE_DIR}")
message(WARNING "OpenSSL_LIBRARIES: ${OPENSSL_LIBRARIES}")
include_directories(${OPENSSL_INCLUDE_DIR})
target_link_libraries(IMAP ${OPENSSL_LIBRARIES})
这是我的 CMAKE 消息的输出:
Warning:Starting CMAKE...
Warning:Boost_INCLUDE_DIR: /usr/local/include
Warning:Boost_LIBRARIES: /usr/local/lib/libboost_system.dylib;/usr/local/lib/libboost_thread.dylib;/usr/local/lib/libboost_regex.dylib;/usr/local/lib/libboost_chrono.dylib;/usr/local/lib/libboost_date_time.dylib;/usr/local/lib/libboost_atomic.dylib
Warning:Boost_VERSION: 106100
Warning:OpenSSL_VERSION: 1.1.0
Warning:OpenSSL_INCLUDE_DIR: /usr/local/include
Warning:OpenSSL_LIBRARIES: /usr/local/lib/libssl.dylib;/usr/local/lib/libcrypto.dylib
当我尝试构建项目时，我收到以下一堆错误:
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:43:23: error: expected unqualified-id
mutexes_.resize(::CRYPTO_num_locks());
^
/usr/local/include/openssl/crypto.h:218:41: note: expanded from macro 'CRYPTO_num_locks'
# define CRYPTO_num_locks() (0)
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:46:66: error: expected unqualified-id
::CRYPTO_set_locking_callback(&do_init::openssl_locking_func);
^
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:47:56: error: expected unqualified-id
::CRYPTO_set_id_callback(&do_init::openssl_id_func);
^
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:64:32: error: expected unqualified-id
::CRYPTO_set_id_callback(0);
^
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:65:37: error: expected unqualified-id
::CRYPTO_set_locking_callback(0);
^
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:66:7: error: expected unqualified-id
::ERR_free_strings();
^
/usr/local/include/openssl/err.h:241:29: note: expanded from macro 'ERR_free_strings'
# define ERR_free_strings() while(0) continue
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:68:7: warning: 'ERR_remove_thread_state' is deprecated [-Wdeprecated-declarations]
::ERR_remove_thread_state(NULL);
^
/usr/local/include/openssl/err.h:244:25: note: 'ERR_remove_thread_state' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(void ERR_remove_thread_state(void *))
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:72:7: error: expected unqualified-id
::EVP_cleanup();
^
/usr/local/include/openssl/evp.h:865:25: note: expanded from macro 'EVP_cleanup'
# define EVP_cleanup() while(0) continue
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:73:7: error: expected unqualified-id
::CRYPTO_cleanup_all_ex_data();
^
/usr/local/include/openssl/crypto.h:206:39: note: expanded from macro 'CRYPTO_cleanup_all_ex_data'
# define CRYPTO_cleanup_all_ex_data() while(0) continue
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:76:7: error: expected unqualified-id
::ENGINE_cleanup();
^
/usr/local/include/openssl/engine.h:508:27: note: expanded from macro 'ENGINE_cleanup'
# define ENGINE_cleanup() while(0) continue
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:29:
In file included from /usr/local/include/boost/asio/ssl/detail/openssl_init.hpp:100:
/usr/local/include/boost/asio/ssl/detail/impl/openssl_init.ipp:106:16: error: use of undeclared identifier 'CRYPTO_LOCK'
if (mode & CRYPTO_LOCK)
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:83:31: error: no member named 'SSLv2_method' in the global namespace
handle_ = ::SSL_CTX_new(::SSLv2_method());
~~^
/usr/local/include/boost/asio/ssl/impl/context.ipp:86:31: error: no member named 'SSLv2_client_method' in the global namespace
handle_ = ::SSL_CTX_new(::SSLv2_client_method());
~~^
/usr/local/include/boost/asio/ssl/impl/context.ipp:89:31: error: no member named 'SSLv2_server_method' in the global namespace
handle_ = ::SSL_CTX_new(::SSLv2_server_method());
~~^
/usr/local/include/boost/asio/ssl/impl/context.ipp:111:31: warning: 'TLSv1_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_method());
^
/usr/local/include/openssl/ssl.h:1556:45: note: 'TLSv1_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_method(void)) /* TLSv1.0 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:114:31: warning: 'TLSv1_client_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_client_method());
^
/usr/local/include/openssl/ssl.h:1558:45: note: 'TLSv1_client_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_client_method(void)) /* TLSv1.0 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:117:31: warning: 'TLSv1_server_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_server_method());
^
/usr/local/include/openssl/ssl.h:1557:45: note: 'TLSv1_server_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_server_method(void)) /* TLSv1.0 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:130:31: warning: 'TLSv1_1_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_1_method());
^
/usr/local/include/openssl/ssl.h:1562:45: note: 'TLSv1_1_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_method(void)) /* TLSv1.1 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:133:31: warning: 'TLSv1_1_client_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_1_client_method());
^
/usr/local/include/openssl/ssl.h:1564:45: note: 'TLSv1_1_client_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_client_method(void)) /* TLSv1.1 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:136:31: warning: 'TLSv1_1_server_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_1_server_method());
^
/usr/local/include/openssl/ssl.h:1563:45: note: 'TLSv1_1_server_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_1_server_method(void)) /* TLSv1.1 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:148:31: warning: 'TLSv1_2_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_2_method());
^
/usr/local/include/openssl/ssl.h:1568:45: note: 'TLSv1_2_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_method(void)) /* TLSv1.2 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:151:31: warning: 'TLSv1_2_client_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_2_client_method());
^
/usr/local/include/openssl/ssl.h:1570:45: note: 'TLSv1_2_client_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_client_method(void)) /* TLSv1.2 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:154:31: warning: 'TLSv1_2_server_method' is deprecated [-Wdeprecated-declarations]
handle_ = ::SSL_CTX_new(::TLSv1_2_server_method());
^
/usr/local/include/openssl/ssl.h:1569:45: note: 'TLSv1_2_server_method' has been explicitly marked deprecated here
DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_server_method(void)) /* TLSv1.2 */
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:208:16: error: member access into incomplete type 'SSL_CTX' (aka 'ssl_ctx_st')
if (handle_->default_passwd_callback_userdata)
^
/usr/local/include/openssl/ossl_typ.h:144:16: note: forward declaration of 'ssl_ctx_st'
typedef struct ssl_ctx_st SSL_CTX;
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:212:20: error: member access into incomplete type 'SSL_CTX' (aka 'ssl_ctx_st')
handle_->default_passwd_callback_userdata);
^
/usr/local/include/openssl/ossl_typ.h:144:16: note: forward declaration of 'ssl_ctx_st'
typedef struct ssl_ctx_st SSL_CTX;
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:212:22: error: expected ')'
handle_->default_passwd_callback_userdata);
^
/usr/local/include/boost/asio/ssl/impl/context.ipp:211:53: note: to match this '('
static_cast<detail::password_callback_base*>(
^
/usr/local/include/boost/asio/ssl/impl/context.ipp:214:14: error: member access into incomplete type 'SSL_CTX' (aka 'ssl_ctx_st')
handle_->default_passwd_callback_userdata = 0;
^
/usr/local/include/openssl/ossl_typ.h:144:16: note: forward declaration of 'ssl_ctx_st'
typedef struct ssl_ctx_st SSL_CTX;
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:551:18: error: member access into incomplete type 'SSL_CTX' (aka 'ssl_ctx_st')
handle_->default_passwd_callback,
^
/usr/local/include/openssl/ossl_typ.h:144:16: note: forward declaration of 'ssl_ctx_st'
typedef struct ssl_ctx_st SSL_CTX;
^
In file included from /path/to/my/code/JMail/IMAP/main.cpp:4:
In file included from /path/to/my/code/JMail/IMAP/IMAPClient.h:6:
In file included from /path/to/my/code/JMail/IMAP/TLSSocket.h:9:
In file included from /usr/local/include/boost/asio/ssl.hpp:19:
In file included from /usr/local/include/boost/asio/ssl/context.hpp:786:
/usr/local/include/boost/asio/ssl/impl/context.ipp:552:18: error: member access into incomplete type 'SSL_CTX' (aka 'ssl_ctx_st')
handle_->default_passwd_callback_userdata) };
^
/usr/local/include/openssl/ossl_typ.h:144:16: note: forward declaration of 'ssl_ctx_st'
typedef struct ssl_ctx_st SSL_CTX;
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
10 warnings and 20 errors generated.
被引用的 TLSSocket 类基本上只是 Boost Asio SSL 示例的包装器:
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>
void TLSSocket::connect() {
boost::asio::io_service io_service;
boost::asio::ip::tcp::resolver resolver(io_service);
boost::asio::ip::tcp::resolver::query query(this->address, this->port);
boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve(query);
boost::asio::ssl::context ctx(boost::asio::ssl::context::tlsv1);
mSocket = new boost::asio::ssl::stream<boost::asio::ip::tcp::socket>(io_service, ctx);
mSocket->set_verify_mode(boost::asio::ssl::verify_peer);
mSocket->set_verify_callback(boost::bind(&TLSSocket::on_verify_certificate, this, _1, _2));
boost::asio::async_connect(mSocket->lowest_layer(), iterator,
boost::bind(&TLSSocket::on_connect, this, boost::asio::placeholders::error));
io_service.run();
}
void TLSSocket::disconnect() {
mSocket->lowest_layer().cancel();
}
TLSSocket::TLSSocket(std::string address, std::string port) {
this->address = address;
this->port = port;
mSocket = nullptr;
}
void *TLSSocket::send(IMAPRequest *request) {
boost::asio::streambuf requestBuff;
std::ostream request_stream(&requestBuff);
request_stream << request->getTag() << " " << request->getCommand() << " " << request->getContent() << "\r\n";
boost::asio::write(*mSocket, requestBuff);
for (; ;) {
boost::array<char, 128> buffer;
boost::system::error_code error;
size_t len = mSocket->read_some(boost::asio::buffer(buffer), error);
if (error == boost::asio::error::eof)
break;
else if (error)
throw boost::system::system_error(error);
std::cout.write(buffer.data(), len);
}
}
void TLSSocket::on_connect(const boost::system::error_code& error){
if(!error) {
try {
mSocket->async_handshake(boost::asio::ssl::stream_base::handshake_type ::client,
boost::bind(&TLSSocket::on_handshake, this, boost::asio::placeholders::error));
} catch (std::exception ex){
std::cout << "Handshaking error: " << ex.what() << "\n";
}
} else {
std::cout << "Connect error: " << error.message() << "\n";
}
}
void TLSSocket::on_handshake(const boost::system::error_code& error){
if(!error){
} else {
std::cout << "Handshaking error: " << error.message() << "\n";
}
}
bool TLSSocket::on_verify_certificate(bool verified, boost::asio::ssl::verify_context &ctx) {
char subject_name[256];
X509* cert = X509_STORE_CTX_get_current_cert(ctx.native_handle());
X509_NAME_oneline(X509_get_subject_name(cert), subject_name, 256);
std::cout << "Verifying " << subject_name << "\n";
return verified;
}
在我看来它甚至没有进入编译的链接阶段，它只是试图为我的 main.cpp 制作 .o 文件。如果我在我的 IDE 中打开它提示的文件之一，IDE 会突出显示语法错误，但我很困惑为什么。
我是不是把 include 的顺序放错了？我的 CMAKE 文件有问题吗？我是否错误地构建了 OpenSSL 或 Boost？
如有任何帮助，我们将不胜感激。我断断续续地研究了几个星期，大部分时间都花在了构建上(我猜是 C++ 第一课 :))。
最佳答案
在我看来，Boost 尚未更新为与 OpenSSL 1.1.0 一起使用。 OpenSSL 1.0.2 和 1.1.0 之间有许多 API 更改，它们不完全源兼容。我建议您使用 1.0.2，直到 Boost 更新为可以使用新的 OpenSSL 版本(无论如何仍处于测试阶段)。
关于c++ - boost Asio 和 OpenSSL 1.1.0，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37517730/