From 2bf6e66ffe9f617ec56a4cc4561c533a81d80cdf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= Date: Thu, 2 Jul 2015 15:29:06 +0200 Subject: client: handle agent forward open requests with callbacks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Fabiano Fidêncio Reviewed-by: Aris Adamantiadis --- include/libssh/callbacks.h | 15 +++++++++++++++ include/libssh/libssh.h | 4 +++- src/channels.c | 19 +++++++++++++++++++ src/messages.c | 20 ++++++++++++++++++++ 4 files changed, 57 insertions(+), 1 deletion(-) diff --git a/include/libssh/callbacks.h b/include/libssh/callbacks.h index 6bd8c573..20c540e5 100644 --- a/include/libssh/callbacks.h +++ b/include/libssh/callbacks.h @@ -124,6 +124,18 @@ typedef void (*ssh_global_request_callback) (ssh_session session, typedef ssh_channel (*ssh_channel_open_request_x11_callback) (ssh_session session, const char * originator_address, int originator_port, void *userdata); +/** + * @brief Handles an SSH new channel open "auth-agent" request. This happens when the server + * sends back an "auth-agent" connection attempt. This is a client-side API + * @param session current session handler + * @param userdata Userdata to be passed to the callback function. + * @returns a valid ssh_channel handle if the request is to be allowed + * @returns NULL if the request should not be allowed + * @warning The channel pointer returned by this callback must be closed by the application. + */ +typedef ssh_channel (*ssh_channel_open_request_auth_agent_callback) (ssh_session session, + void *userdata); + /** * The structure to replace libssh functions with appropriate callbacks. */ @@ -154,6 +166,9 @@ struct ssh_callbacks_struct { /** This function will be called when an incoming X11 request is received. */ ssh_channel_open_request_x11_callback channel_open_request_x11_function; + /** This function will be called when an incoming "auth-agent" request is received. + */ + ssh_channel_open_request_auth_agent_callback channel_open_request_auth_agent_function; }; typedef struct ssh_callbacks_struct *ssh_callbacks; diff --git a/include/libssh/libssh.h b/include/libssh/libssh.h index e52317f9..232d7c2b 100644 --- a/include/libssh/libssh.h +++ b/include/libssh/libssh.h @@ -188,7 +188,8 @@ enum ssh_channel_type_e { SSH_CHANNEL_SESSION, SSH_CHANNEL_DIRECT_TCPIP, SSH_CHANNEL_FORWARDED_TCPIP, - SSH_CHANNEL_X11 + SSH_CHANNEL_X11, + SSH_CHANNEL_AUTH_AGENT }; enum ssh_channel_requests_e { @@ -401,6 +402,7 @@ LIBSSH_API int ssh_channel_request_sftp(ssh_channel channel); LIBSSH_API int ssh_channel_request_subsystem(ssh_channel channel, const char *subsystem); LIBSSH_API int ssh_channel_request_x11(ssh_channel channel, int single_connection, const char *protocol, const char *cookie, int screen_number); +LIBSSH_API int ssh_channel_request_auth_agent(ssh_channel channel); LIBSSH_API int ssh_channel_send_eof(ssh_channel channel); LIBSSH_API int ssh_channel_select(ssh_channel *readchans, ssh_channel *writechans, ssh_channel *exceptchans, struct timeval * timeout); diff --git a/src/channels.c b/src/channels.c index 2c841ed3..d8cd1907 100644 --- a/src/channels.c +++ b/src/channels.c @@ -1981,6 +1981,25 @@ ssh_channel ssh_channel_accept_x11(ssh_channel channel, int timeout_ms) { return ssh_channel_accept(channel->session, SSH_CHANNEL_X11, timeout_ms, NULL); } +/** + * @brief Send an "auth-agent-req" channel request over an existing session channel. + * + * This client-side request will enable forwarding the agent over an secure tunnel. + * When the server is ready to open one authentication agent channel, an + * ssh_channel_open_request_auth_agent_callback event will be generated. + * + * @param[in] channel The channel to send signal. + * + * @return SSH_OK on success, SSH_ERROR if an error occurred + */ +int ssh_channel_request_auth_agent(ssh_channel channel) { + if (channel == NULL) { + return SSH_ERROR; + } + + return channel_request(channel, "auth-agent-req@openssh.com", NULL, 0); +} + /** * @internal * diff --git a/src/messages.c b/src/messages.c index d906e696..ec538771 100644 --- a/src/messages.c +++ b/src/messages.c @@ -293,6 +293,21 @@ static int ssh_execute_client_request(ssh_session session, ssh_message msg) ssh_message_reply_default(msg); } + return SSH_OK; + } else if (msg->type == SSH_REQUEST_CHANNEL_OPEN + && msg->channel_request_open.type == SSH_CHANNEL_AUTH_AGENT + && ssh_callbacks_exists(session->common.callbacks, channel_open_request_auth_agent_function)) { + channel = session->common.callbacks->channel_open_request_auth_agent_function (session, + session->common.callbacks->userdata); + + if (channel != NULL) { + rc = ssh_message_channel_request_open_reply_accept_channel(msg, channel); + + return rc; + } else { + ssh_message_reply_default(msg); + } + return SSH_OK; } @@ -1070,6 +1085,11 @@ SSH_PACKET_CALLBACK(ssh_packet_channel_open){ goto end; } + if (strcmp(type_c,"auth-agent@openssh.com") == 0) { + msg->channel_request_open.type = SSH_CHANNEL_AUTH_AGENT; + goto end; + } + msg->channel_request_open.type = SSH_CHANNEL_UNKNOWN; goto end; -- cgit v1.2.3