packet.h - security/openssh-library - Rivoreo Source Code Repositories

 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
  * Interface for the packet protocol functions.
  *
  * As far as I am concerned, the code I have written for this software
  * can be used freely for any purpose.  Any derived versions of this
  * software must be clearly marked as such, and if the derived work is
  * incompatible with the protocol description in the RFC file, it must be
  * called by a name other than "ssh" or "Secure Shell".
  */

 /* RCSID("$OpenBSD: packet.h,v 1.19 2001/01/13 18:32:50 markus Exp $"); */

 #ifndef PACKET_H
 #define PACKET_H

 #include <openssl/bn.h>

 /*
  * Sets the socket used for communication.  Disables encryption until
  * packet_set_encryption_key is called.  It is permissible that fd_in and
  * fd_out are the same descriptor; in that case it is assumed to be a socket.
  */
 void    packet_set_connection(int fd_in, int fd_out);

 /* Puts the connection file descriptors into non-blocking mode. */
 void    packet_set_nonblocking(void);

 /* Returns the file descriptor used for input. */
 int     packet_get_connection_in(void);

 /* Returns the file descriptor used for output. */
 int     packet_get_connection_out(void);

 /*
  * Closes the connection (both descriptors) and clears and frees internal
  * data structures.
  */
 void    packet_close(void);

 /*
  * Causes any further packets to be encrypted using the given key.  The same
  * key is used for both sending and reception.  However, both directions are
  * encrypted independently of each other.  Cipher types are defined in ssh.h.
  */
 void
 packet_set_encryption_key(const u_char *key, u_int keylen,
     int cipher_type);

 /*
  * Sets remote side protocol flags for the current connection.  This can be
  * called at any time.
  */
 void    packet_set_protocol_flags(u_int flags);

 /* Returns the remote protocol flags set earlier by the above function. */
 u_int packet_get_protocol_flags(void);

 /* Enables compression in both directions starting from the next packet. */
 void    packet_start_compression(int level);

 /*
  * Informs that the current session is interactive.  Sets IP flags for
  * optimal performance in interactive use.
  */
 void    packet_set_interactive(int interactive);

 /* Returns true if the current connection is interactive. */
 int     packet_is_interactive(void);

 /* Starts constructing a packet to send. */
 void    packet_start(int type);

 /* Appends a character to the packet data. */
 void    packet_put_char(int ch);

 /* Appends an integer to the packet data. */
 void    packet_put_int(u_int value);

 /* Appends an arbitrary precision integer to packet data. */
 void    packet_put_bignum(BIGNUM * value);
 void    packet_put_bignum2(BIGNUM * value);

 /* Appends a string to packet data. */
 void    packet_put_string(const char *buf, u_int len);
 void    packet_put_cstring(const char *str);
 void    packet_put_raw(const char *buf, u_int len);

 /*
  * Finalizes and sends the packet.  If the encryption key has been set,
  * encrypts the packet before sending.
  */
 void    packet_send(void);

 /* Waits until a packet has been received, and returns its type. */
 int     packet_read(int *payload_len_ptr);

 /*
  * Waits until a packet has been received, verifies that its type matches
  * that given, and gives a fatal error and exits if there is a mismatch.
  */
 void    packet_read_expect(int *payload_len_ptr, int type);

 /*
  * Checks if a full packet is available in the data received so far via
  * packet_process_incoming.  If so, reads the packet; otherwise returns
  * SSH_MSG_NONE.  This does not wait for data from the connection.
  * SSH_MSG_DISCONNECT is handled specially here.  Also, SSH_MSG_IGNORE
  * messages are skipped by this function and are never returned to higher
  * levels.
  */
 int     packet_read_poll(int *packet_len_ptr);

 /*
  * Buffers the given amount of input characters.  This is intended to be used
  * together with packet_read_poll.
  */
 void    packet_process_incoming(const char *buf, u_int len);

 /* Returns a character (0-255) from the packet data. */
 u_int packet_get_char(void);

 /* Returns an integer from the packet data. */
 u_int packet_get_int(void);

 /*
  * Returns an arbitrary precision integer from the packet data.  The integer
  * must have been initialized before this call.
  */
 void    packet_get_bignum(BIGNUM * value, int *length_ptr);
 void    packet_get_bignum2(BIGNUM * value, int *length_ptr);
 char	*packet_get_raw(int *length_ptr);

 /*
  * Returns a string from the packet data.  The string is allocated using
  * xmalloc; it is the responsibility of the calling program to free it when
  * no longer needed.  The length_ptr argument may be NULL, or point to an
  * integer into which the length of the string is stored.
  */
 char   *packet_get_string(u_int *length_ptr);

 /*
  * Logs the error in syslog using LOG_INFO, constructs and sends a disconnect
  * packet, closes the connection, and exits.  This function never returns.
  * The error message should not contain a newline.  The total length of the
  * message must not exceed 1024 bytes.
  */
 void    packet_disconnect(const char *fmt,...) __attribute__((format(printf, 1, 2)));

 /*
  * Sends a diagnostic message to the other side.  This message can be sent at
  * any time (but not while constructing another message). The message is
  * printed immediately, but only if the client is being executed in verbose
  * mode.  These messages are primarily intended to ease debugging
  * authentication problems.  The total length of the message must not exceed
  * 1024 bytes.  This will automatically call packet_write_wait.  If the
  * remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG,
  * this will do nothing.
  */
 void    packet_send_debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));

 /* Checks if there is any buffered output, and tries to write some of the output. */
 void    packet_write_poll(void);

 /* Waits until all pending output data has been written. */
 void    packet_write_wait(void);

 /* Returns true if there is buffered data to write to the connection. */
 int     packet_have_data_to_write(void);

 /* Returns true if there is not too much data to write to the connection. */
 int     packet_not_very_much_data_to_write(void);

 /* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */
 extern int max_packet_size;
 int     packet_set_maxsize(int s);
 #define packet_get_maxsize() max_packet_size

 /* Stores tty modes from the fd into current packet. */
 void    tty_make_modes(int fd);

 /* Parses tty modes for the fd from the current packet. */
 void    tty_parse_modes(int fd, int *n_bytes_ptr);

 #define packet_integrity_check(payload_len, expected_len, type) \
 do { \
   int _p = (payload_len), _e = (expected_len); \
   if (_p != _e) { \
     log("Packet integrity error (%d != %d) at %s:%d", \
 	_p, _e, __FILE__, __LINE__); \
     packet_disconnect("Packet integrity error. (%d)", (type)); \
   } \
 } while (0)

 #define packet_done() \
 do { \
 	int _len = packet_remaining(); \
 	if (_len > 0) { \
 		log("Packet integrity error (%d bytes remaining) at %s:%d", \
 		    _len ,__FILE__, __LINE__); \
 		packet_disconnect("Packet integrity error."); \
 	} \
 } while (0)

 /* remote host is connected via a socket/ipv4 */
 int	packet_connection_is_on_socket(void);
 int	packet_connection_is_ipv4(void);

 /* enable SSH2 packet format */
 void	packet_set_ssh2_format(void);

 /* returns remaining payload bytes */
 int	packet_remaining(void);

 #endif				/* PACKET_H */
	/*
	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	* All rights reserved
	* Interface for the packet protocol functions.
	*
	* As far as I am concerned, the code I have written for this software
	* can be used freely for any purpose. Any derived versions of this
	* software must be clearly marked as such, and if the derived work is
	* incompatible with the protocol description in the RFC file, it must be
	* called by a name other than "ssh" or "Secure Shell".
	*/

	/* RCSID("$OpenBSD: packet.h,v 1.19 2001/01/13 18:32:50 markus Exp $"); */

	#ifndef PACKET_H
	#define PACKET_H

	#include <openssl/bn.h>

	/*
	* Sets the socket used for communication. Disables encryption until
	* packet_set_encryption_key is called. It is permissible that fd_in and
	* fd_out are the same descriptor; in that case it is assumed to be a socket.
	*/
	void packet_set_connection(int fd_in, int fd_out);

	/* Puts the connection file descriptors into non-blocking mode. */
	void packet_set_nonblocking(void);

	/* Returns the file descriptor used for input. */
	int packet_get_connection_in(void);

	/* Returns the file descriptor used for output. */
	int packet_get_connection_out(void);

	/*
	* Closes the connection (both descriptors) and clears and frees internal
	* data structures.
	*/
	void packet_close(void);

	/*
	* Causes any further packets to be encrypted using the given key. The same
	* key is used for both sending and reception. However, both directions are
	* encrypted independently of each other. Cipher types are defined in ssh.h.
	*/
	void
	packet_set_encryption_key(const u_char *key, u_int keylen,
	int cipher_type);

	/*
	* Sets remote side protocol flags for the current connection. This can be
	* called at any time.
	*/
	void packet_set_protocol_flags(u_int flags);

	/* Returns the remote protocol flags set earlier by the above function. */
	u_int packet_get_protocol_flags(void);

	/* Enables compression in both directions starting from the next packet. */
	void packet_start_compression(int level);

	/*
	* Informs that the current session is interactive. Sets IP flags for
	* optimal performance in interactive use.
	*/
	void packet_set_interactive(int interactive);

	/* Returns true if the current connection is interactive. */
	int packet_is_interactive(void);

	/* Starts constructing a packet to send. */
	void packet_start(int type);

	/* Appends a character to the packet data. */
	void packet_put_char(int ch);

	/* Appends an integer to the packet data. */
	void packet_put_int(u_int value);

	/* Appends an arbitrary precision integer to packet data. */
	void packet_put_bignum(BIGNUM * value);
	void packet_put_bignum2(BIGNUM * value);

	/* Appends a string to packet data. */
	void packet_put_string(const char *buf, u_int len);
	void packet_put_cstring(const char *str);
	void packet_put_raw(const char *buf, u_int len);

	/*
	* Finalizes and sends the packet. If the encryption key has been set,
	* encrypts the packet before sending.
	*/
	void packet_send(void);

	/* Waits until a packet has been received, and returns its type. */
	int packet_read(int *payload_len_ptr);

	/*
	* Waits until a packet has been received, verifies that its type matches
	* that given, and gives a fatal error and exits if there is a mismatch.
	*/
	void packet_read_expect(int *payload_len_ptr, int type);

	/*
	* Checks if a full packet is available in the data received so far via
	* packet_process_incoming. If so, reads the packet; otherwise returns
	* SSH_MSG_NONE. This does not wait for data from the connection.
	* SSH_MSG_DISCONNECT is handled specially here. Also, SSH_MSG_IGNORE
	* messages are skipped by this function and are never returned to higher
	* levels.
	*/
	int packet_read_poll(int *packet_len_ptr);

	/*
	* Buffers the given amount of input characters. This is intended to be used
	* together with packet_read_poll.
	*/
	void packet_process_incoming(const char *buf, u_int len);

	/* Returns a character (0-255) from the packet data. */
	u_int packet_get_char(void);

	/* Returns an integer from the packet data. */
	u_int packet_get_int(void);

	/*
	* Returns an arbitrary precision integer from the packet data. The integer
	* must have been initialized before this call.
	*/
	void packet_get_bignum(BIGNUM * value, int *length_ptr);
	void packet_get_bignum2(BIGNUM * value, int *length_ptr);
	char packet_get_raw(int length_ptr);

	/*
	* Returns a string from the packet data. The string is allocated using
	* xmalloc; it is the responsibility of the calling program to free it when
	* no longer needed. The length_ptr argument may be NULL, or point to an
	* integer into which the length of the string is stored.
	*/
	char packet_get_string(u_int length_ptr);

	/*
	* Logs the error in syslog using LOG_INFO, constructs and sends a disconnect
	* packet, closes the connection, and exits. This function never returns.
	* The error message should not contain a newline. The total length of the
	* message must not exceed 1024 bytes.
	*/
	void packet_disconnect(const char *fmt,...) __attribute__((format(printf, 1, 2)));

	/*
	* Sends a diagnostic message to the other side. This message can be sent at
	* any time (but not while constructing another message). The message is
	* printed immediately, but only if the client is being executed in verbose
	* mode. These messages are primarily intended to ease debugging
	* authentication problems. The total length of the message must not exceed
	* 1024 bytes. This will automatically call packet_write_wait. If the
	* remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG,
	* this will do nothing.
	*/
	void packet_send_debug(const char *fmt,...) __attribute__((format(printf, 1, 2)));

	/* Checks if there is any buffered output, and tries to write some of the output. */
	void packet_write_poll(void);

	/* Waits until all pending output data has been written. */
	void packet_write_wait(void);

	/* Returns true if there is buffered data to write to the connection. */
	int packet_have_data_to_write(void);

	/* Returns true if there is not too much data to write to the connection. */
	int packet_not_very_much_data_to_write(void);

	/* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */
	extern int max_packet_size;
	int packet_set_maxsize(int s);
	#define packet_get_maxsize() max_packet_size

	/* Stores tty modes from the fd into current packet. */
	void tty_make_modes(int fd);

	/* Parses tty modes for the fd from the current packet. */
	void tty_parse_modes(int fd, int *n_bytes_ptr);

	#define packet_integrity_check(payload_len, expected_len, type) \
	do { \
	int _p = (payload_len), _e = (expected_len); \
	if (_p != _e) { \
	log("Packet integrity error (%d != %d) at %s:%d", \
	_p, _e, __FILE__, __LINE__); \
	packet_disconnect("Packet integrity error. (%d)", (type)); \
	} \
	} while (0)

	#define packet_done() \
	do { \
	int _len = packet_remaining(); \
	if (_len > 0) { \
	log("Packet integrity error (%d bytes remaining) at %s:%d", \
	_len ,__FILE__, __LINE__); \
	packet_disconnect("Packet integrity error."); \
	} \
	} while (0)

	/* remote host is connected via a socket/ipv4 */
	int packet_connection_is_on_socket(void);
	int packet_connection_is_ipv4(void);

	/* enable SSH2 packet format */
	void packet_set_ssh2_format(void);

	/* returns remaining payload bytes */
	int packet_remaining(void);

	#endif /* PACKET_H */