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Diffstat (limited to 'src/network/tcp_socket_handler.hpp')
| -rw-r--r-- | src/network/tcp_socket_handler.hpp | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/src/network/tcp_socket_handler.hpp b/src/network/tcp_socket_handler.hpp new file mode 100644 index 0000000..f68698e --- /dev/null +++ b/src/network/tcp_socket_handler.hpp @@ -0,0 +1,238 @@ +#pragma once + +#include "biboumi.h" + +#include <network/socket_handler.hpp> +#include <network/resolver.hpp> + +#include <network/credentials_manager.hpp> + +#include <sys/types.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> + +#include <chrono> +#include <vector> +#include <memory> +#include <string> +#include <list> + +#ifdef BOTAN_FOUND + +# include <botan/types.h> +# include <botan/botan.h> +# include <botan/tls_session_manager.h> +# include <network/tls_policy.hpp> + +# if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,32) +# define BOTAN_TLS_CALLBACKS_OVERRIDE override final +# else +# define BOTAN_TLS_CALLBACKS_OVERRIDE +# endif +#endif + +/** + * Does all the read/write, buffering etc. With optional tls. + * But doesn’t do any connect() or accept() or anything else. + */ +class TCPSocketHandler: public SocketHandler +#ifdef BOTAN_FOUND +# if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,32) + ,public Botan::TLS::Callbacks +# endif +#endif +{ +protected: + ~TCPSocketHandler(); +public: + explicit TCPSocketHandler(std::shared_ptr<Poller>& poller); + TCPSocketHandler(const TCPSocketHandler&) = delete; + TCPSocketHandler(TCPSocketHandler&&) = delete; + TCPSocketHandler& operator=(const TCPSocketHandler&) = delete; + TCPSocketHandler& operator=(TCPSocketHandler&&) = delete; + + /** + * Reads raw data from the socket. And pass it to parse_in_buffer() + * If we are using TLS on this connection, we call tls_recv() + */ + void on_recv() override final; + /** + * Write as much data from out_buf as possible, in the socket. + */ + void on_send() override final; + /** + * Add the given data to out_buf and tell our poller that we want to be + * notified when a send event is ready. + * + * This can be overriden if we want to modify the data before sending + * it. For example if we want to encrypt it. + */ + void send_data(std::string&& data); + /** + * Watch the socket for send events, if our out buffer is not empty. + */ + void send_pending_data(); + /** + * Close the connection, remove us from the poller + */ + virtual void close(); + /** + * Handle/consume (some of) the data received so far. The data to handle + * may be in the in_buf buffer, or somewhere else, depending on what + * get_receive_buffer() returned. If some data is used from in_buf, it + * should be truncated, only the unused data should be left untouched. + * + * The size argument is the size of the last chunk of data that was added to the buffer. + * + * The function should call consume_in_buffer, with the size that was consumed by the + * “parsing”, and thus to be removed from the input buffer. + */ + virtual void parse_in_buffer(const size_t size) = 0; +#ifdef BOTAN_FOUND + /** + * Tell whether the credential manager should cancel the connection when the + * certificate is invalid. + */ + virtual bool abort_on_invalid_cert() const + { + return true; + } +#endif + bool is_using_tls() const; + +private: + /** + * Reads from the socket into the provided buffer. If an error occurs + * (read returns <= 0), the handling of the error is done here (close the + * connection, log a message, etc). + * + * Returns the value returned by ::recv(), so the buffer should not be + * used if it’s not positive. + */ + ssize_t do_recv(void* recv_buf, const size_t buf_size); + /** + * Reads data from the socket and calls parse_in_buffer with it. + */ + void plain_recv(); + /** + * Mark the given data as ready to be sent, as-is, on the socket, as soon + * as we can. + */ + void raw_send(std::string&& data); + + protected: + virtual bool is_connecting() const = 0; +#ifdef BOTAN_FOUND + /** + * Create the TLS::Client object, with all the callbacks etc. This must be + * called only when we know we are able to send TLS-encrypted data over + * the socket. + */ + void start_tls(const std::string& address, const std::string& port); + private: + /** + * An additional step to pass the data into our tls object to decrypt it + * before passing it to parse_in_buffer. + */ + void tls_recv(); + /** + * Pass the data to the tls object in order to encrypt it. The tls object + * will then call raw_send as a callback whenever data as been encrypted + * and can be sent on the socket. + */ + void tls_send(std::string&& data); + /** + * Called by the tls object that some data has been decrypt. We call + * parse_in_buffer() to handle that unencrypted data. + */ + void tls_record_received(uint64_t rec_no, const Botan::byte* data, size_t size) BOTAN_TLS_CALLBACKS_OVERRIDE; + /** + * Called by the tls object to indicate that some data has been encrypted + * and is now ready to be sent on the socket as is. + */ + void tls_emit_data(const Botan::byte* data, size_t size) BOTAN_TLS_CALLBACKS_OVERRIDE; + /** + * Called by the tls object to indicate that a TLS alert has been + * received. We don’t use it, we just log some message, at the moment. + */ + void tls_alert(Botan::TLS::Alert alert) BOTAN_TLS_CALLBACKS_OVERRIDE; + /** + * Called by the tls object at the end of the TLS handshake. We don't do + * anything here appart from logging the TLS session information. + */ + bool tls_session_established(const Botan::TLS::Session& session) BOTAN_TLS_CALLBACKS_OVERRIDE; + +#if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(1,11,34) + void tls_verify_cert_chain(const std::vector<Botan::X509_Certificate>& cert_chain, + const std::vector<std::shared_ptr<const Botan::OCSP::Response>>& ocsp_responses, + const std::vector<Botan::Certificate_Store*>& trusted_roots, + Botan::Usage_Type usage, + const std::string& hostname, + const Botan::TLS::Policy& policy) BOTAN_TLS_CALLBACKS_OVERRIDE; +#endif + /** + * Called whenever the tls session goes from inactive to active. This + * means that the handshake has just been successfully done, and we can + * now proceed to send any available data into our tls object. + */ + void on_tls_activated(); +#endif // BOTAN_FOUND + /** + * Where data is added, when we want to send something to the client. + */ + std::vector<std::string> out_buf; +protected: + /** + * Whether we are using TLS on this connection or not. + */ + bool use_tls; + /** + * Where data read from the socket is added until we can extract a full + * and meaningful “message” from it. + * + * TODO: something more efficient than a string. + */ + std::string in_buf; + /** + * Remove the given “size” first bytes from our in_buf. + */ + void consume_in_buffer(const std::size_t size); + /** + * Provide a buffer in which data can be directly received. This can be + * used to avoid copying data into in_buf before using it. If no buffer + * needs to be provided, nullptr is returned (the default implementation + * does that), in that case our internal in_buf will be used to save the + * data until it can be used by parse_in_buffer(). + */ + virtual void* get_receive_buffer(const size_t size) const; + /** + * Called when we detect a disconnection from the remote host. + */ + virtual void on_connection_close(const std::string&) {} + virtual void on_connection_failed(const std::string&) {} + +#ifdef BOTAN_FOUND +protected: + BasicCredentialsManager credential_manager; +private: + BiboumiTLSPolicy policy; + /** + * We use a unique_ptr because we may not want to create the object at + * all. The Botan::TLS::Client object generates a handshake message and + * calls the output_fn callback with it as soon as it is created. + * Therefore, we do not want to create it if we do not intend to send any + * TLS-encrypted message. We create the object only when needed (for + * example after we have negociated a TLS session using a STARTTLS + * message, or stuf like that). + * + * See start_tls for the method where this object is created. + */ + std::unique_ptr<Botan::TLS::Client> tls; + /** + * An additional buffer to keep data that the user wants to send, but + * cannot because the handshake is not done. + */ + std::vector<Botan::byte> pre_buf; +#endif // BOTAN_FOUND +}; |