5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 1997 - 2000 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
24 /* Amount of bytes to be read from the socket connection at once. */
25 #define SILC_PACKET_READ_SIZE 16384
27 /* Default byte size of the packet. This can be set larger if this
28 is not enough, we shall see. */
29 #define SILC_PACKET_DEFAULT_SIZE 2048
31 /* Header length without source and destination ID's. */
32 #define SILC_PACKET_HEADER_LEN 8 + 2
34 /* Minimum length of SILC Packet Header. This much is decrypted always
35 when packet is received to be able to get all the relevant data out
37 #define SILC_PACKET_MIN_HEADER_LEN 16 + 2
39 /* Maximum padding length */
40 #define SILC_PACKET_MAX_PADLEN 16
42 /* Minimum packet length */
43 #define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
45 /* Maximum length of ID */
46 #define SILC_PACKET_MAX_ID_LEN 16
48 /* SILC packet type definition. For now, it is defined like this and I don't
49 expect it to change in any near future. If one byte as a packet type is
50 not enough we can, then, think something else. */
51 typedef unsigned char SilcPacketType;
53 /* SILC packet version type definition. */
54 typedef unsigned char SilcPacketVersion;
56 /* SILC packet flags type definition. */
57 typedef unsigned char SilcPacketFlags;
59 /* All defined packet flags */
60 #define SILC_PACKET_FLAG_NONE 0x00
61 #define SILC_PACKET_FLAG_PRIVMSG_KEY 0x01
62 #define SILC_PACKET_FLAG_FORWARDED 0x02
63 #define SILC_PACKET_FLAG_BROADCAST 0x04
64 #define SILC_PACKET_FLAG_TUNNELED 0x08
65 /* Rest of flags still available
66 #define SILC_PACKET_FLAG_XXX 0x10
67 #define SILC_PACKET_FLAG_XXX 0x20
68 #define SILC_PACKET_FLAG_XXX 0x40
69 #define SILC_PACKET_FLAG_XXX 0x80
75 In packet sending this is filled and sent to silc_packet_assemble
76 which then uses it to assemble new packet. In packet reception pointer
77 to this context is sent to silc_packet_parse which parses the packet
78 and returns the relevant information to this structure. On packet
79 reception returned ID's are always the hash values of the ID's from
82 Short description of the fields following:
90 Type of the packet. Types are defined below.
94 Packet flags. Flags are defined above.
97 unsigned int src_id_len
98 unsigned char src_id_type
100 Source ID, its length and type. On packet reception retuned ID's
101 are always the hash values of the ID's from the packet.
103 unsigned char *dst_id;
104 unsigned int dst_id_len;
105 unsigned char src_id_type;
107 Destination ID, its length and type. On packet reception retuned
108 ID's are always the hash values of the ID's from the packet.
112 Pointer to allocated hash object. This must be MD5 hash object.
113 This is used to calculate checksum of the packet.
119 SilcPacketFlags flags;
121 unsigned char *src_id;
122 unsigned int src_id_len;
123 unsigned char src_id_type;
125 unsigned char *dst_id;
126 unsigned int dst_id_len;
127 unsigned char dst_id_type;
129 unsigned int truelen;
132 /* For padding generation */
137 SilcSocketConnection sock;
141 Silc Packet Parser context.
143 This context is used in packet reception when silc_packet_receive_process
144 function calls parser callback that performs the actual packet decryption
145 and parsing. This context is sent as argument to the parser function.
146 This context must be free'd by the parser callback function.
148 Following description of the fields:
150 SilcPacketContext *packet
152 The actual packet received from the network. In this phase the
153 context is not parsed, only the packet->buffer is allocated and
154 it includes the raw packet data, which is encrypted.
156 SilcSocketConnection sock
158 The associated connection.
162 The cipher to be used in the decryption.
166 The HMAC to be used in the decryption.
170 User context that is sent to the silc_packet_receive_process
171 function. This usually includes application and connection specific
177 SilcPacketContext *packet;
178 SilcSocketConnection sock;
182 } SilcPacketParserContext;
184 /* The parser callback function. */
185 typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
189 /* SILC Packet types. */
190 #define SILC_PACKET_NONE 0 /* NULL, never sent */
191 #define SILC_PACKET_DISCONNECT 1 /* Disconnection */
192 #define SILC_PACKET_SUCCESS 2 /* Success */
193 #define SILC_PACKET_FAILURE 3 /* Failure */
194 #define SILC_PACKET_REJECT 4 /* Rejected */
195 #define SILC_PACKET_NOTIFY 5 /* Notify message */
196 #define SILC_PACKET_ERROR 6 /* Error message */
197 #define SILC_PACKET_CHANNEL_MESSAGE 7 /* Message for channel */
198 #define SILC_PACKET_CHANNEL_KEY 8 /* Key of the channel */
199 #define SILC_PACKET_PRIVATE_MESSAGE 9 /* Private message */
200 #define SILC_PACKET_PRIVATE_MESSAGE_KEY 10 /* Private message key*/
201 #define SILC_PACKET_COMMAND 11 /* Command */
202 #define SILC_PACKET_COMMAND_REPLY 12 /* Reply to a command */
203 #define SILC_PACKET_KEY_EXCHANGE 13 /* Start of KE */
204 #define SILC_PACKET_KEY_EXCHANGE_1 14 /* KE1 */
205 #define SILC_PACKET_KEY_EXCHANGE_2 15 /* KE2 */
206 #define SILC_PACKET_CONNECTION_AUTH_REQUEST 16 /* Request of auth meth */
207 #define SILC_PACKET_CONNECTION_AUTH 17 /* Connectinon auth */
208 #define SILC_PACKET_NEW_ID 18 /* Sending new ID */
209 #define SILC_PACKET_NEW_ID_LIST 19 /* Sending list of them */
210 #define SILC_PACKET_NEW_CLIENT 20 /* Registering client */
211 #define SILC_PACKET_NEW_SERVER 21 /* Registering server */
212 #define SILC_PACKET_NEW_CHANNEL 22 /* Registering channel */
213 #define SILC_PACKET_NEW_CHANNEL_USER 23 /* "" user on channel */
214 #define SILC_PACKET_NEW_CHANNEL_LIST 24 /* List of new channels */
215 #define SILC_PACKET_NEW_CHANNEL_USER_LIST 25 /* List of users on "" */
216 #define SILC_PACKET_REPLACE_ID 26 /* To replace old ID */
217 #define SILC_PACKET_REMOVE_ID 27 /* To remove ID */
218 #define SILC_PACKET_REMOVE_CHANNEL_USER 28 /* Remove user from channel */
219 #define SILC_PACKET_REKEY 29
220 #define SILC_PACKET_REKEY_DONE 30
221 /* #define SILC_PACKET_MAX 255 */
225 /* Returns true length of the packet and padded length of the packet */
226 #define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_padlen) \
228 SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
229 (__ret_padlen) = (((__ret_truelen) - 2) + \
230 SILC_PACKET_MAX_PADLEN) & ~(SILC_PACKET_MAX_PADLEN - 1); \
233 /* Returns pad length of the packet */
234 #define SILC_PACKET_PADLEN(__packetlen) \
235 SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
238 int silc_packet_write(int sock, SilcBuffer src);
239 int silc_packet_send(SilcSocketConnection sock, int force_send);
240 void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
241 SilcBuffer buffer, unsigned int len);
242 void silc_packet_assemble(SilcPacketContext *ctx);
243 void silc_packet_send_prepare(SilcSocketConnection sock,
244 unsigned int header_len,
246 unsigned int data_len);
247 int silc_packet_read(int sock, SilcBuffer dest);
248 int silc_packet_receive(SilcSocketConnection sock);
249 int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
250 SilcBuffer buffer, SilcPacketContext *packet);
251 void silc_packet_receive_process(SilcSocketConnection sock,
252 SilcCipher cipher, SilcHmac hmac,
253 SilcPacketParserCallback parser,
255 SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
256 SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
257 SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx);