From 7aa7794e3e944895c0b1b4635669affc93800968 Mon Sep 17 00:00:00 2001
From: Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
Date: Tue, 6 Mar 2018 22:03:53 +0100
Subject: [PATCH] work in progress on ssl implementation

---
 examples/libev.cpp           |  2 +-
 src/linux_tcp/function.h     |  5 +-
 src/linux_tcp/library.h      | 64 --------------------------
 src/linux_tcp/openssl.cpp    | 89 +++++++++++++++++++++++++++---------
 src/linux_tcp/openssl.h      |  3 ++
 src/linux_tcp/sslconnected.h | 16 ++++++-
 src/linux_tcp/sslcontext.h   |  4 +-
 src/linux_tcp/sslhandshake.h | 14 +++---
 src/linux_tcp/sslshutdown.h  |  4 +-
 src/linux_tcp/sslwrapper.h   |  4 +-
 src/linux_tcp/tcpconnected.h |  2 +-
 src/linux_tcp/tcpinbuffer.h  | 13 +++++-
 src/linux_tcp/tcpoutbuffer.h |  5 +-
 src/linux_tcp/tcpresolver.h  |  2 +-
 14 files changed, 118 insertions(+), 109 deletions(-)
 delete mode 100644 src/linux_tcp/library.h

diff --git a/examples/libev.cpp b/examples/libev.cpp
index 4d909f6..9ee0e2a 100644
--- a/examples/libev.cpp
+++ b/examples/libev.cpp
@@ -66,7 +66,7 @@ int main()
     MyHandler handler(loop);
 
     // init the SSL library
-//    SSL_library_init();
+    SSL_library_init();
 
     // make a connection
     AMQP::Address address("amqps://guest:guest@localhost/");
diff --git a/src/linux_tcp/function.h b/src/linux_tcp/function.h
index b243643..fa1250d 100644
--- a/src/linux_tcp/function.h
+++ b/src/linux_tcp/function.h
@@ -119,11 +119,10 @@ private:
 public:
     /**
      *  Constructor
-     *  @param  library     The library to load the function from
      *  @param  name        Name of the function
      */
-    Function(void *library, const char *name) :
-        _method(dlsym(library, name)) {}
+    Function(const char *name) :
+        _method(dlsym(RTLD_DEFAULT, name)) {}
 
     /**
      *  Destructor
diff --git a/src/linux_tcp/library.h b/src/linux_tcp/library.h
deleted file mode 100644
index 7330eda..0000000
--- a/src/linux_tcp/library.h
+++ /dev/null
@@ -1,64 +0,0 @@
-/**
- *  Library.h
- * 
- *  The Library class is a wrapper around dlopen()
- * 
- *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
- *  @copyright 2018 Copernica BV
- */
-
-/**
- *  Include guard
- */
-#pragma once
-
-/**
- *  Begin of namespace
- */
-namespace AMQP {
-
-/**
- *  Class definition
- */
-class Library
-{
-private:
-    /**
-     *  The library handle
-     *  @var void *
-     */
-    void *_handle;
-    
-public:
-    /**
-     *  Constructor
-     */
-    Library() : _handle(dlopen(nullptr, RTLD_NOW)) {}
-    
-    /**
-     *  No copying
-     *  @param  that
-     */
-    Library(const Library &that) = delete;
-    
-    /**
-     *  Destructor
-     */
-    virtual ~Library()
-    {
-        // close library
-        if (_handle) dlclose(_handle);
-    }
-    
-    /**
-     *  Cast to the handle
-     *  @return void *
-     */
-    operator void * () { return _handle; }
-};
-    
-/**
- *  End of namespace
- */
-}
-
diff --git a/src/linux_tcp/openssl.cpp b/src/linux_tcp/openssl.cpp
index 8e9139d..39bff69 100644
--- a/src/linux_tcp/openssl.cpp
+++ b/src/linux_tcp/openssl.cpp
@@ -11,7 +11,6 @@
  */
 #include "openssl.h"
 #include "function.h"
-#include "library.h"
 
 /**
  *  Begin of namespace
@@ -19,16 +18,35 @@
 namespace AMQP { namespace OpenSSL {
 
 /**
- *  Get the library handle
- *  @return void *
+ *  Is the openssl library loaded?
+ *  @return bool
  */
-static void *library()
+bool valid()
 {
-    // create on instance
-    static Library instance;
+    // create a function
+    static Function<decltype(::SSL_CTX_new)> func("SSL_CTX_new");
+
+    // we need a library
+    return func;
+}
+
+/**
+ *  Get the SSL_METHOD for outgoing connections
+ *  @return SSL_METHOD *
+ */
+const SSL_METHOD *TLS_client_method()
+{
+    // create a function that loads the method
+    static Function<decltype(TLS_client_method)> func("TLS_client_method");
     
-    // return the instance (it has a cast-to-void-ptr operator)
-    return instance;
+    // call the openssl function
+    if (func) return func();
+    
+    // older openssl libraries do not have this function, so we try to load an other function
+    static Function<decltype(TLS_client_method)> old("SSLv23_client_method");
+    
+    // call the old one
+    return old();
 }
 
 /**
@@ -39,7 +57,7 @@ static void *library()
 SSL_CTX *SSL_CTX_new(const SSL_METHOD *method) 
 {
     // create a function
-    static Function<decltype(::SSL_CTX_new)> func(library(), "SSL_CTX_new");
+    static Function<decltype(::SSL_CTX_new)> func("SSL_CTX_new");
     
     // call the openssl function
     return func(method);
@@ -55,7 +73,7 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *method)
 int SSL_read(SSL *ssl, void *buf, int num)
 {
     // create a function
-    static Function<decltype(::SSL_read)> func(library(), "SSL_read");
+    static Function<decltype(::SSL_read)> func("SSL_read");
     
     // call the openssl function
     return func(ssl, buf, num);
@@ -71,7 +89,7 @@ int SSL_read(SSL *ssl, void *buf, int num)
 int SSL_write(SSL *ssl, const void *buf, int num)
 {
     // create a function
-    static Function<decltype(::SSL_write)> func(library(), "SSL_write");
+    static Function<decltype(::SSL_write)> func("SSL_write");
     
     // call the openssl function
     return func(ssl, buf, num);
@@ -86,12 +104,24 @@ int SSL_write(SSL *ssl, const void *buf, int num)
 int SSL_set_fd(SSL *ssl, int fd) 
 {
     // create a function
-    static Function<decltype(::SSL_set_fd)> func(library(), "SSL_set_fd");
+    static Function<decltype(::SSL_set_fd)> func("SSL_set_fd");
     
     // call the openssl function
     return func(ssl, fd);
 }
 
+/**
+ *  Free an allocated ssl context
+ *  @param  ctx
+ */
+void SSL_CTX_free(SSL_CTX *ctx)
+{
+    // create a function
+    static Function<decltype(::SSL_CTX_free)> func("SSL_CTX_free");
+    
+    // call the openssl function
+    return func(ctx);
+}
 
 /**
  *  Free an allocated SSL structure
@@ -101,7 +131,7 @@ int SSL_set_fd(SSL *ssl, int fd)
 void SSL_free(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_free)> func(library(), "SSL_free");
+    static Function<decltype(::SSL_free)> func("SSL_free");
     
     // call the openssl function
     return func(ssl);
@@ -115,7 +145,7 @@ void SSL_free(SSL *ssl)
 SSL *SSL_new(SSL_CTX *ctx)
 {
     // create a function
-    static Function<decltype(::SSL_new)> func(library(), "SSL_new");
+    static Function<decltype(::SSL_new)> func("SSL_new");
     
     // call the openssl function
     return func(ctx);
@@ -129,7 +159,7 @@ SSL *SSL_new(SSL_CTX *ctx)
 int SSL_up_ref(SSL *ssl)
 {
     // create a function
-    static Function<decltype(SSL_up_ref)> func(library(), "SSL_up_ref");
+    static Function<decltype(SSL_up_ref)> func("SSL_up_ref");
     
     // call the openssl function if it exists
     if (func) return func(ssl);
@@ -147,7 +177,7 @@ int SSL_up_ref(SSL *ssl)
 int SSL_shutdown(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_shutdown)> func(library(), "SSL_shutdown");
+    static Function<decltype(::SSL_shutdown)> func("SSL_shutdown");
     
     // call the openssl function
     return func(ssl);
@@ -160,7 +190,7 @@ int SSL_shutdown(SSL *ssl)
 void SSL_set_connect_state(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_set_connect_state)> func(library(), "SSL_set_connect_state");
+    static Function<decltype(::SSL_set_connect_state)> func("SSL_set_connect_state");
     
     // call the openssl function
     func(ssl);
@@ -175,7 +205,7 @@ void SSL_set_connect_state(SSL *ssl)
 int SSL_do_handshake(SSL *ssl)
 {
     // create a function
-    static Function<decltype(::SSL_do_handshake)> func(library(), "SSL_do_handshake");
+    static Function<decltype(::SSL_do_handshake)> func("SSL_do_handshake");
     
     // call the openssl function
     return func(ssl);
@@ -183,18 +213,35 @@ int SSL_do_handshake(SSL *ssl)
 
 /**
  *  Obtain result code for TLS/SSL I/O operation
- *  @param ssl      SSL object
- *  @param ret      the returned diagnostic value of SSL calls
+ *  @param  ssl     SSL object
+ *  @param  ret     the returned diagnostic value of SSL calls
  *  @return int     returns error values
  */
 int SSL_get_error(const SSL *ssl, int ret)
 {
     // create a function
-    static Function<decltype(::SSL_get_error)> func(library(), "SSL_get_error");
+    static Function<decltype(::SSL_get_error)> func("SSL_get_error");
     
     // call the openssl function
     return func(ssl, ret);
 }
+
+/**
+ *  Internal handling function for a ssl context
+ *  @param  ssl     ssl context
+ *  @param  cmd     command 
+ *  @param  larg    first arg
+ *  @param  parg    second arg
+ *  @return long
+ */
+long SSL_ctrl(SSL *ssl, int cmd, long larg, void *parg)
+{
+    // create a function
+    static Function<decltype(::SSL_ctrl)> func("SSL_ctrl");
+    
+    // call the openssl function
+    return func(ssl, cmd, larg, parg);
+}
     
 /**
  *  End of namespace
diff --git a/src/linux_tcp/openssl.h b/src/linux_tcp/openssl.h
index 9a21dc9..387654d 100644
--- a/src/linux_tcp/openssl.h
+++ b/src/linux_tcp/openssl.h
@@ -33,6 +33,7 @@ bool valid();
 /**
  *  List of all wrapper methods that are in use inside AMQP-CPP
  */
+const SSL_METHOD *TLS_client_method();
 SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
 SSL     *SSL_new(SSL_CTX *ctx);
 int      SSL_do_handshake(SSL *ssl);
@@ -43,7 +44,9 @@ int      SSL_set_fd(SSL *ssl, int fd);
 int      SSL_get_error(const SSL *ssl, int ret);
 int      SSL_up_ref(SSL *ssl);
 void     SSL_set_connect_state(SSL *ssl);
+void     SSL_CTX_free(SSL_CTX *ctx);
 void     SSL_free(SSL *ssl);
+long     SSL_ctrl(SSL *ssl, int cmd, long larg, void *parg);
 
 /**
  *  End of namespace
diff --git a/src/linux_tcp/sslconnected.h b/src/linux_tcp/sslconnected.h
index 1ad708b..b6e5d21 100644
--- a/src/linux_tcp/sslconnected.h
+++ b/src/linux_tcp/sslconnected.h
@@ -148,7 +148,7 @@ private:
     TcpState *repeat(int result)
     {
         // error was returned, so we must investigate what is going on
-        auto error = SSL_get_error(_ssl, result);
+        auto error = OpenSSL::SSL_get_error(_ssl, result);
                         
         // check the error
         switch (error) {
@@ -286,6 +286,20 @@ public:
         }
     }
 
+    /**
+     *  Flush the connection, sent all buffered data to the socket
+     *  @return TcpState    new tcp state
+     */
+    virtual TcpState *flush() override
+    {
+        // create an object to wait for the filedescriptor to becomes active
+        Wait wait(_socket);
+        
+        // @todo implementation
+        
+        return this;
+    }
+
     /**
      *  Send data over the connection
      *  @param  buffer      buffer to send
diff --git a/src/linux_tcp/sslcontext.h b/src/linux_tcp/sslcontext.h
index a53c04d..2c2d8b3 100644
--- a/src/linux_tcp/sslcontext.h
+++ b/src/linux_tcp/sslcontext.h
@@ -35,7 +35,7 @@ public:
      *  @param  method
      *  @throws std::runtime_error
      */
-    SslContext(const SSL_METHOD *method) : _ctx(SSL_CTX_new(method)) 
+    SslContext(const SSL_METHOD *method) : _ctx(OpenSSL::SSL_CTX_new(method)) 
     {
         // report error
         if (_ctx == nullptr) throw std::runtime_error("failed to construct ssl context");
@@ -69,7 +69,7 @@ public:
     virtual ~SslContext()
     {
         // free resource (this updates the refcount -1, and may destruct it)
-        SSL_CTX_free(_ctx);
+        OpenSSL::SSL_CTX_free(_ctx);
     }
     
     /**
diff --git a/src/linux_tcp/sslhandshake.h b/src/linux_tcp/sslhandshake.h
index fb8af3b..4095664 100644
--- a/src/linux_tcp/sslhandshake.h
+++ b/src/linux_tcp/sslhandshake.h
@@ -111,18 +111,18 @@ public:
      */
     SslHandshake(TcpConnection *connection, int socket, const std::string &hostname, TcpOutBuffer &&buffer, TcpHandler *handler) : 
         TcpState(connection, handler),
-        _ssl(SslContext(SSLv23_client_method())),
+        _ssl(SslContext(OpenSSL::TLS_client_method())),
         _socket(socket),
         _out(std::move(buffer))
     {       
         // we will be using the ssl context as a client
-        SSL_set_connect_state(_ssl);
+        OpenSSL::SSL_set_connect_state(_ssl);
         
         // associate domain name with the connection
-        SSL_set_tlsext_host_name(_ssl, hostname.data());
+        OpenSSL::SSL_ctrl(_ssl, SSL_CTRL_SET_TLSEXT_HOSTNAME, TLSEXT_NAMETYPE_host_name, (void *)hostname.data());
         
         // associate the ssl context with the socket filedescriptor
-        if (SSL_set_fd(_ssl, socket) == 0) throw std::runtime_error("failed to associate filedescriptor with ssl socket");
+        if (OpenSSL::SSL_set_fd(_ssl, socket) == 0) throw std::runtime_error("failed to associate filedescriptor with ssl socket");
         
         // we are going to wait until the socket becomes writable before we start the handshake
         _handler->monitor(_connection, _socket, writable);
@@ -164,7 +164,7 @@ public:
         if (result == 1) return nextstate(new SslConnected(_connection, _socket, _ssl, std::move(_out), _handler));
         
         // error was returned, so we must investigate what is going on
-        auto error = SSL_get_error(_ssl, result);
+        auto error = OpenSSL::SSL_get_error(_ssl, result);
                             
         // check the error
         switch (error) {
@@ -198,13 +198,13 @@ public:
         while (true)
         {
             // start the ssl handshake
-            int result = SSL_do_handshake(_ssl);
+            int result = OpenSSL::SSL_do_handshake(_ssl);
         
             // if the connection succeeds, we can move to the ssl-connected state
             if (result == 1) return nextstate(new SslConnected(_connection, _socket, _ssl, std::move(_out), _handler));
         
             // error was returned, so we must investigate what is going on
-            auto error = SSL_get_error(_ssl, result);
+            auto error = OpenSSL::SSL_get_error(_ssl, result);
             
             // check the error
             switch (error) 
diff --git a/src/linux_tcp/sslshutdown.h b/src/linux_tcp/sslshutdown.h
index 4a0315e..2361155 100644
--- a/src/linux_tcp/sslshutdown.h
+++ b/src/linux_tcp/sslshutdown.h
@@ -70,7 +70,7 @@ private:
     TcpState *repeat(int result)
     {
         // error was returned, so we must investigate what is going on
-        auto error = SSL_get_error(_ssl, result);
+        auto error = OpenSSL::SSL_get_error(_ssl, result);
                         
         // check the error
         switch (error) {
@@ -145,7 +145,7 @@ public:
         Monitor monitor(this);
 
         // close the connection
-        auto result = SSL_shutdown(_ssl);
+        auto result = OpenSSL::SSL_shutdown(_ssl);
             
         // if this is a success, we can proceed with the event loop
         if (result > 0) return proceed();
diff --git a/src/linux_tcp/sslwrapper.h b/src/linux_tcp/sslwrapper.h
index 5c88810..6aa5edd 100644
--- a/src/linux_tcp/sslwrapper.h
+++ b/src/linux_tcp/sslwrapper.h
@@ -34,7 +34,7 @@ public:
      *  Constructor
      *  @param  ctx
      */
-    SslWrapper(SSL_CTX *ctx) : _ssl(SSL_new(ctx)) 
+    SslWrapper(SSL_CTX *ctx) : _ssl(OpenSSL::SSL_new(ctx)) 
     {
         // report error
         if (_ssl == nullptr) throw std::runtime_error("failed to construct ssl structure");
@@ -68,7 +68,7 @@ public:
     virtual ~SslWrapper()
     {
         // destruct object
-        SSL_free(_ssl);
+        OpenSSL::SSL_free(_ssl);
     }
     
     /**
diff --git a/src/linux_tcp/tcpconnected.h b/src/linux_tcp/tcpconnected.h
index 670b3db..4aeb8e8 100644
--- a/src/linux_tcp/tcpconnected.h
+++ b/src/linux_tcp/tcpconnected.h
@@ -225,7 +225,7 @@ public:
         // create an object to wait for the filedescriptor to becomes active
         Wait wait(_socket);
 
-        // keep running until the out buffer is empty
+        // keep running until the out buffer is not empty
         while (_out)
         {
             // poll the socket, is it already writable?
diff --git a/src/linux_tcp/tcpinbuffer.h b/src/linux_tcp/tcpinbuffer.h
index bd020e3..79b708f 100644
--- a/src/linux_tcp/tcpinbuffer.h
+++ b/src/linux_tcp/tcpinbuffer.h
@@ -121,8 +121,17 @@ public:
      */
     ssize_t receivefrom(SSL *ssl, uint32_t expected)
     {
-        // @todo implementation
-        return 0;
+        // number of bytes to that still fit in the buffer
+        size_t bytes = expected - _size;
+        
+        // read data
+        auto result = OpenSSL::SSL_read(ssl, (void *)(_data + _size), bytes);
+        
+        // update total buffer size on success
+        if (result > 0) _size += result;
+        
+        // done
+        return result;
     }
     
     /**
diff --git a/src/linux_tcp/tcpoutbuffer.h b/src/linux_tcp/tcpoutbuffer.h
index 8d18526..31dbd27 100644
--- a/src/linux_tcp/tcpoutbuffer.h
+++ b/src/linux_tcp/tcpoutbuffer.h
@@ -18,7 +18,8 @@
  */
 #include <sys/ioctl.h>
 #include <sys/uio.h>
-#include <openssl/ssl.h>
+#include "openssl.h"
+
 /**
  *  FIONREAD on Solaris is defined elsewhere
  */
@@ -284,7 +285,7 @@ public:
         if (buffers == 0) return 0;
         
         // send the data
-        auto result = SSL_write(ssl, buffer[0].iov_base, buffer[0].iov_len);
+        auto result = OpenSSL::SSL_write(ssl, buffer[0].iov_base, buffer[0].iov_len);
         
         // on success we shrink the buffer
         if (result > 0) shrink(result);
diff --git a/src/linux_tcp/tcpresolver.h b/src/linux_tcp/tcpresolver.h
index be45c4f..ee24e2d 100644
--- a/src/linux_tcp/tcpresolver.h
+++ b/src/linux_tcp/tcpresolver.h
@@ -93,7 +93,7 @@ private:
         try
         {
             // check if we support openssl in the first place
-            if (!OpenSSL::valid()) throw std::runtime_error("Secure connection cannot be established: the application has no access to openssl");
+            if (!OpenSSL::valid()) throw std::runtime_error("Secure connection cannot be established: libssl.so cannot be loaded");
             
             // get address info
             AddressInfo addresses(_hostname.data(), _port);