Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 4 | * All rights reserved |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 5 | * Interface for the packet protocol functions. |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 6 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 7 | * As far as I am concerned, the code I have written for this software |
| 8 | * can be used freely for any purpose. Any derived versions of this |
| 9 | * software must be clearly marked as such, and if the derived work is |
| 10 | * incompatible with the protocol description in the RFC file, it must be |
| 11 | * called by a name other than "ssh" or "Secure Shell". |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 12 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 13 | |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 14 | /* RCSID("$OpenBSD: packet.h,v 1.17 2000/09/07 20:27:52 deraadt Exp $"); */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 15 | |
| 16 | #ifndef PACKET_H |
| 17 | #define PACKET_H |
| 18 | |
| 19 | #include <openssl/bn.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 20 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 21 | /* |
| 22 | * Sets the socket used for communication. Disables encryption until |
| 23 | * packet_set_encryption_key is called. It is permissible that fd_in and |
| 24 | * fd_out are the same descriptor; in that case it is assumed to be a socket. |
| 25 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 26 | void packet_set_connection(int fd_in, int fd_out); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 27 | |
| 28 | /* Puts the connection file descriptors into non-blocking mode. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 29 | void packet_set_nonblocking(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 30 | |
| 31 | /* Returns the file descriptor used for input. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 32 | int packet_get_connection_in(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 33 | |
| 34 | /* Returns the file descriptor used for output. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 35 | int packet_get_connection_out(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 36 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 37 | /* |
| 38 | * Closes the connection (both descriptors) and clears and frees internal |
| 39 | * data structures. |
| 40 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 41 | void packet_close(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 42 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 43 | /* |
| 44 | * Causes any further packets to be encrypted using the given key. The same |
| 45 | * key is used for both sending and reception. However, both directions are |
| 46 | * encrypted independently of each other. Cipher types are defined in ssh.h. |
| 47 | */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 48 | void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 49 | packet_set_encryption_key(const unsigned char *key, unsigned int keylen, |
| 50 | int cipher_type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 51 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 52 | /* |
| 53 | * Sets remote side protocol flags for the current connection. This can be |
| 54 | * called at any time. |
| 55 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 56 | void packet_set_protocol_flags(unsigned int flags); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 57 | |
| 58 | /* Returns the remote protocol flags set earlier by the above function. */ |
| 59 | unsigned int packet_get_protocol_flags(void); |
| 60 | |
| 61 | /* Enables compression in both directions starting from the next packet. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 62 | void packet_start_compression(int level); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 63 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 64 | /* |
| 65 | * Informs that the current session is interactive. Sets IP flags for |
| 66 | * optimal performance in interactive use. |
| 67 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 68 | void packet_set_interactive(int interactive, int keepalives); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 69 | |
| 70 | /* Returns true if the current connection is interactive. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 71 | int packet_is_interactive(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 72 | |
| 73 | /* Starts constructing a packet to send. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 74 | void packet_start(int type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 75 | |
| 76 | /* Appends a character to the packet data. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 77 | void packet_put_char(int ch); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 78 | |
| 79 | /* Appends an integer to the packet data. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 80 | void packet_put_int(unsigned int value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 81 | |
| 82 | /* Appends an arbitrary precision integer to packet data. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 83 | void packet_put_bignum(BIGNUM * value); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 84 | void packet_put_bignum2(BIGNUM * value); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 85 | |
| 86 | /* Appends a string to packet data. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 87 | void packet_put_string(const char *buf, unsigned int len); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 88 | void packet_put_cstring(const char *str); |
| 89 | void packet_put_raw(const char *buf, unsigned int len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 90 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 91 | /* |
| 92 | * Finalizes and sends the packet. If the encryption key has been set, |
| 93 | * encrypts the packet before sending. |
| 94 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 95 | void packet_send(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 96 | |
| 97 | /* Waits until a packet has been received, and returns its type. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 98 | int packet_read(int *payload_len_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 99 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 100 | /* |
| 101 | * Waits until a packet has been received, verifies that its type matches |
| 102 | * that given, and gives a fatal error and exits if there is a mismatch. |
| 103 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 104 | void packet_read_expect(int *payload_len_ptr, int type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 105 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 106 | /* |
| 107 | * Checks if a full packet is available in the data received so far via |
| 108 | * packet_process_incoming. If so, reads the packet; otherwise returns |
| 109 | * SSH_MSG_NONE. This does not wait for data from the connection. |
| 110 | * SSH_MSG_DISCONNECT is handled specially here. Also, SSH_MSG_IGNORE |
| 111 | * messages are skipped by this function and are never returned to higher |
| 112 | * levels. |
| 113 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 114 | int packet_read_poll(int *packet_len_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 115 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 116 | /* |
| 117 | * Buffers the given amount of input characters. This is intended to be used |
| 118 | * together with packet_read_poll. |
| 119 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 120 | void packet_process_incoming(const char *buf, unsigned int len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 121 | |
| 122 | /* Returns a character (0-255) from the packet data. */ |
| 123 | unsigned int packet_get_char(void); |
| 124 | |
| 125 | /* Returns an integer from the packet data. */ |
| 126 | unsigned int packet_get_int(void); |
| 127 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 128 | /* |
| 129 | * Returns an arbitrary precision integer from the packet data. The integer |
| 130 | * must have been initialized before this call. |
| 131 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 132 | void packet_get_bignum(BIGNUM * value, int *length_ptr); |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 133 | void packet_get_bignum2(BIGNUM * value, int *length_ptr); |
| 134 | char *packet_get_raw(int *length_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 135 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 136 | /* |
| 137 | * Returns a string from the packet data. The string is allocated using |
| 138 | * xmalloc; it is the responsibility of the calling program to free it when |
| 139 | * no longer needed. The length_ptr argument may be NULL, or point to an |
| 140 | * integer into which the length of the string is stored. |
| 141 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 142 | char *packet_get_string(unsigned int *length_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 143 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 144 | /* |
| 145 | * Logs the error in syslog using LOG_INFO, constructs and sends a disconnect |
| 146 | * packet, closes the connection, and exits. This function never returns. |
| 147 | * The error message should not contain a newline. The total length of the |
| 148 | * message must not exceed 1024 bytes. |
| 149 | */ |
Damien Miller | 7684ee1 | 2000-03-17 23:40:15 +1100 | [diff] [blame] | 150 | void packet_disconnect(const char *fmt,...) __attribute__((format(printf, 1, 2))); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 151 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 152 | /* |
| 153 | * Sends a diagnostic message to the other side. This message can be sent at |
| 154 | * any time (but not while constructing another message). The message is |
| 155 | * printed immediately, but only if the client is being executed in verbose |
| 156 | * mode. These messages are primarily intended to ease debugging |
| 157 | * authentication problems. The total length of the message must not exceed |
| 158 | * 1024 bytes. This will automatically call packet_write_wait. If the |
| 159 | * remote side protocol flags do not indicate that it supports SSH_MSG_DEBUG, |
| 160 | * this will do nothing. |
| 161 | */ |
Damien Miller | 7684ee1 | 2000-03-17 23:40:15 +1100 | [diff] [blame] | 162 | void packet_send_debug(const char *fmt,...) __attribute__((format(printf, 1, 2))); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 163 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 164 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 165 | void packet_write_poll(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 166 | |
| 167 | /* Waits until all pending output data has been written. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 168 | void packet_write_wait(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 169 | |
| 170 | /* Returns true if there is buffered data to write to the connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 171 | int packet_have_data_to_write(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 172 | |
| 173 | /* Returns true if there is not too much data to write to the connection. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 174 | int packet_not_very_much_data_to_write(void); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 175 | |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 176 | /* maximum packet size, requested by client with SSH_CMSG_MAX_PACKET_SIZE */ |
| 177 | extern int max_packet_size; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 178 | int packet_set_maxsize(int s); |
Damien Miller | 6162d12 | 1999-11-21 13:23:52 +1100 | [diff] [blame] | 179 | #define packet_get_maxsize() max_packet_size |
| 180 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 181 | /* Stores tty modes from the fd into current packet. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 182 | void tty_make_modes(int fd); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 183 | |
| 184 | /* Parses tty modes for the fd from the current packet. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 185 | void tty_parse_modes(int fd, int *n_bytes_ptr); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 186 | |
| 187 | #define packet_integrity_check(payload_len, expected_len, type) \ |
| 188 | do { \ |
| 189 | int _p = (payload_len), _e = (expected_len); \ |
| 190 | if (_p != _e) { \ |
| 191 | log("Packet integrity error (%d != %d) at %s:%d", \ |
| 192 | _p, _e, __FILE__, __LINE__); \ |
| 193 | packet_disconnect("Packet integrity error. (%d)", (type)); \ |
| 194 | } \ |
| 195 | } while (0) |
| 196 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 197 | #define packet_done() \ |
| 198 | do { \ |
| 199 | int _len = packet_remaining(); \ |
| 200 | if (_len > 0) { \ |
| 201 | log("Packet integrity error (%d bytes remaining) at %s:%d", \ |
| 202 | _len ,__FILE__, __LINE__); \ |
| 203 | packet_disconnect("Packet integrity error."); \ |
| 204 | } \ |
| 205 | } while (0) |
| 206 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 207 | /* remote host is connected via a socket/ipv4 */ |
| 208 | int packet_connection_is_on_socket(void); |
| 209 | int packet_connection_is_ipv4(void); |
| 210 | |
Damien Miller | 33b1356 | 2000-04-04 14:38:59 +1000 | [diff] [blame] | 211 | /* enable SSH2 packet format */ |
| 212 | void packet_set_ssh2_format(void); |
| 213 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 214 | /* returns remaining payload bytes */ |
| 215 | int packet_remaining(void); |
| 216 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 217 | #endif /* PACKET_H */ |