*/
-/****h* silccore/SilcPacketAPI
+/****h* silccore/Packet Protocol Interface
*
* DESCRIPTION
*
#define SILC_PACKET_DEFAULT_SIZE SILC_SOCKET_BUF_SIZE
/* Header length without source and destination ID's. */
-#define SILC_PACKET_HEADER_LEN 8 + 2
+#define SILC_PACKET_HEADER_LEN 10
/* Minimum length of SILC Packet Header. This much is decrypted always
when packet is received to be able to get all the relevant data out
from the header. */
-#define SILC_PACKET_MIN_HEADER_LEN 16 + 2
+#define SILC_PACKET_MIN_HEADER_LEN 16
/* Maximum padding length */
-#define SILC_PACKET_MAX_PADLEN 16
+#define SILC_PACKET_MAX_PADLEN 128
+
+/* Default padding length */
+#define SILC_PACKET_DEFAULT_PADLEN 16
/* Minimum packet length */
#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
+/* Maximum packet length */
+#define SILC_PACKET_MAX_LEN 0xffff
+
/* Maximum length of ID */
-#define SILC_PACKET_MAX_ID_LEN 16
+#define SILC_PACKET_MAX_ID_LEN 28
/****d* silccore/SilcPacketAPI/SilcPacketType
*
* Packet flags. Flags are defined above.
*
* unsigned char *src_id
- * uint16 src_id_len
+ * SilcUInt8 src_id_len
* unsigned char src_id_type
*
* Source ID, its length and type. On packet reception retuned ID's
* are always the hash values of the ID's from the packet.
*
* unsigned char *dst_id;
- * uint16 dst_id_len;
+ * SilcUInt8 dst_id_len;
* unsigned char src_id_type;
*
* Destination ID, its length and type. On packet reception retuned
* ID's are always the hash values of the ID's from the packet.
*
- * uint16 truelen
- * uint16 padlen
+ * SilcUInt16 truelen
+ * SilcUInt8 padlen
*
* The true lenght of the packet and the padded length of the packet.
* These may be set by the caller before calling any of the
* calling silc_packet_context_dup and decreased by calling the
* silc_packet_context_free.
*
- * uint32 sequence;
+ * SilcUInt32 sequence;
*
* Packet sequence number.
*
***/
typedef struct {
SilcBuffer buffer;
- SilcPacketType type;
+
+ SilcUInt16 truelen;
SilcPacketFlags flags;
+ SilcPacketType type;
+ SilcUInt8 padlen;
unsigned char *src_id;
- uint16 src_id_len;
- unsigned char src_id_type;
+ SilcUInt8 src_id_len;
+ SilcUInt8 src_id_type;
unsigned char *dst_id;
- uint16 dst_id_len;
- unsigned char dst_id_type;
-
- uint16 truelen;
- uint16 padlen;
-
- /* Back pointers */
- void *context;
- SilcSocketConnection sock;
+ SilcUInt8 dst_id_len;
+ SilcUInt8 dst_id_type;
int users;
+ bool long_pad; /* Set to TRUE to use maximum padding
+ in packet (up to 256 bytes). */
- uint32 sequence;
+ SilcUInt32 sequence;
} SilcPacketContext;
/****s* silccore/SilcPacketAPI/SilcPacketParserContext
*
* DESCRIPTION
*
- * This context is used in packet reception when silc_packet_receive_process
- * function calls parser callback that performs the actual packet decryption
- * and parsing. This context is sent as argument to the parser function.
- * This context must be free'd by the parser callback function.
+ * This context is used in packet reception when the function
+ * silc_packet_receive_process calls parser callback that performs
+ * the actual packet decryption and parsing. This context is sent as
+ * argument to the parser function. This context must be free'd by
+ * the parser callback function.
*
* Following description of the fields:
*
* context is not parsed, only the packet->buffer is allocated and
* it includes the raw packet data, which is encrypted.
*
+ * bool normal
+ *
+ * Indicates whether the received packet is normal or special packet.
+ * If special the parsing process is special also.
+ *
* SilcSocketConnection sock
*
* The associated connection.
***/
typedef struct {
SilcPacketContext *packet;
+ bool normal;
SilcSocketConnection sock;
void *context;
} SilcPacketParserContext;
*
* SYNOPSIS
*
- * typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
+ * typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
* *parse_context);
*
* DESCRIPTION
* context. The application receiving the SilcPacketParserContext
* must free it.
*
- ***/
-typedef void (*SilcPacketParserCallback)(SilcPacketParserContext
- *parse_context);
-
-/****f* silccore/SilcPacketAPI/SilcPacketCheckDecrypt
- *
- * SYNOPSIS
- *
- * typedef int (*SilcPacketCheckDecrypt)(SilcPacketType packet_type,
- * SilcBuffer buffer,
- * SilcPacketContext *packet,
- * void *context);
- *
- * DESCRIPTION
- *
- * This callback function relates to the checking whether the packet is
- * normal packet or special packet and how it should be processed. If
- * the callback returns TRUE the packet is normal and FALSE if the packet
- * is special and requires special procesing. Some of the packets in
- * SILC are special (like channel message packets that are encrypted
- * using channel specific keys) and requires special processing. That
- * is the reason for this callback function.
- *
- * The library will call this function if provided for the
- * silc_packet_decrypt function. The `packet_type' is the type of
- * packet received (this is also actually the first time application
- * receives information of the received packet, next time it receives
- * it is when the SilcPacketParserCallback function is called),
- * the `buffer' is the raw packet data the `packet' the allocated
- * SilcPacketContext that is filled when parsing the packet and `context'
- * is application specific user context.
+ * This returns TRUE if the library should continue packet processing
+ * (assuming there is more data to be processed), and FALSE if the
+ * upper layer does not want the library to continue but to leave the
+ * rest of the data is the packet queue untouched. Application may
+ * want to do this for example if the cipher is not ready before
+ * processing a certain packet. In this case the application wants
+ * to recall the processing function with the correct cipher.
*
***/
-typedef int (*SilcPacketCheckDecrypt)(SilcPacketType packet_type,
- SilcBuffer buffer,
- SilcPacketContext *packet,
- void *context);
+typedef bool (*SilcPacketParserCallback)(SilcPacketParserContext
+ *parse_context, void *context);
/* Macros */
*
* DESCRIPTION
*
- * Returns true length of the packet and padded length of the packet.
- * This is primarily used by the libary in packet parsing phase but
- * the application may use it as well if needed.
+ * Returns true length of the packet. This is primarily used by the
+ * libary in packet parsing phase but the application may use it as
+ * well if needed.
*
* SOURCE
*/
-#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_padlen) \
-do { \
- SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
- (__ret_padlen) = (((__ret_truelen) - 2) + \
- SILC_PACKET_MAX_PADLEN) & ~(SILC_PACKET_MAX_PADLEN - 1); \
+#define SILC_PACKET_LENGTH(__packet, __ret_truelen, __ret_paddedlen) \
+do { \
+ SILC_GET16_MSB((__ret_truelen), (__packet)->data); \
+ (__ret_paddedlen) = (__ret_truelen) + (__packet)->data[4]; \
} while(0)
/***/
+/****d* silccore/SilcPacketAPI/SILC_PACKET_DATALEN
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_DATALEN ...
+ *
+ * DESCRIPTION
+ *
+ * Calculates the data length with given header length. This macro
+ * can be used to check whether the data_len with header_len exceeds
+ * SILC_PACKET_MAX_LEN. If it does, this returns the new data_len
+ * so that the SILC_PACKET_MAX_LEN is not exceeded. If the data_len
+ * plus header_len fits SILC_PACKET_MAX_LEN the returned data length
+ * is the data_len given as argument. This macro can be used when
+ * assembling packet.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_DATALEN(data_len, header_len) \
+ ((data_len + header_len) > SILC_PACKET_MAX_LEN ? \
+ data_len - ((data_len + header_len) - SILC_PACKET_MAX_LEN) : data_len)
+/***/
+
/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN
*
* NAME
*
* SOURCE
*/
-#define SILC_PACKET_PADLEN(__packetlen) \
- SILC_PACKET_MAX_PADLEN - ((__packetlen) - 2) % SILC_PACKET_MAX_PADLEN;
+#define SILC_PACKET_PADLEN(__packetlen, __blocklen) \
+ SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)
+/***/
+
+/****d* silccore/SilcPacketAPI/SILC_PACKET_PADLEN_MAX
+ *
+ * NAME
+ *
+ * #define SILC_PACKET_PADLEN_MAX ...
+ *
+ * DESCRIPTION
+ *
+ * Returns the length of the padding up to the maximum length, which
+ * is 128 butes. This is used by various library routines to determine
+ * needed padding length.
+ *
+ * SOURCE
+ */
+#define SILC_PACKET_PADLEN_MAX(__packetlen) \
+ SILC_PACKET_MAX_PADLEN - (__packetlen) % SILC_PACKET_MAX_PADLEN
/***/
/* Prototypes */
* SYNOPSIS
*
* void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
- * SilcBuffer buffer, uint32 len);
+ * SilcBuffer buffer, SilcUInt32 len);
*
* DESCRIPTION
*
* cannot be used.
*
***/
-void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, uint32 len);
+void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, SilcUInt32 sequence,
+ SilcBuffer buffer, SilcUInt32 len);
/****f* silccore/SilcPacketAPI/silc_packet_assemble
*
* SYNOPSIS
*
- * void silc_packet_assemble(SilcPacketContext *ctx);
+ * bool silc_packet_assemble(SilcPacketContext *packet, SilcRng rng,
+ * SilcCipher cipher, SilcHmac hmac,
+ * SilcSocketConnection sock,
+ * const unsigned char *data, SilcUInt32 data_len,
+ * const SilcBuffer assembled_packet);
*
* DESCRIPTION
*
- * Assembles a new packet to be ready for send out. The buffer sent as
- * argument must include the data to be sent and it must not be encrypted.
- * The packet also must have enough free space so that the SILC header
- * and padding maybe added to the packet. The packet is encrypted after
- * this function has returned.
- *
- * The buffer sent as argument should be something like following:
- *
- * --------------------------------------------
- * | head | data | tail |
- * --------------------------------------------
- * ^ ^
- * 58 bytes x bytes
- *
- * So that the SILC header and 1 - 16 bytes of padding can fit to
- * the buffer. After assembly the buffer might look like this:
- *
- * --------------------------------------------
- * | data | |
- * --------------------------------------------
- * ^ ^
- * Start of assembled packet
- *
- * Packet construct is as follows (* = won't be encrypted):
- *
- * n bytes SILC Header
- * 2 bytes Payload length (*)
- * 1 byte Flags
- * 1 byte Packet type
- * 2 bytes Source ID Length
- * 2 bytes Destination ID Length
- * 1 byte Source ID Type
- * n bytes Source ID
- * 1 byte Destination ID Type
- * n bytes Destination ID
- *
- * 1 - 16 bytes Padding
- *
- * n bytes Data payload
- *
- * All fields in the packet will be authenticated by MAC. The MAC is
- * not computed here, it must be computed separately before encrypting
- * the packet.
+ * Assembles new packet to be ready for encrypting and sending out.
+ * The `packet' is filled by caller to include the packet header specific
+ * values. This prepares the socket connection's `sock' outoing buffer
+ * for sending data, and returns the assembled packet to the
+ * `assembled_packet' pointer sent by the caller. The `assembled_packet'
+ * is a reference to the socket connection's outgoing buffer. The
+ * returned packet can be encrypted, and then sent to network by calling
+ * silc_packet_send function.
*
***/
-void silc_packet_assemble(SilcPacketContext *ctx);
+bool silc_packet_assemble(SilcPacketContext *packet, SilcRng rng,
+ SilcCipher cipher, SilcHmac hmac,
+ SilcSocketConnection sock,
+ const unsigned char *data, SilcUInt32 data_len,
+ const SilcBuffer assembled_packet);
/****f* silccore/SilcPacketAPI/silc_packet_send_prepare
*
* SYNOPSIS
*
- * void silc_packet_send_prepare(SilcSocketConnection sock,
- * uint32 header_len,
- * uint32 padlen,
- * uint32 data_len);
+ * bool silc_packet_send_prepare(SilcSocketConnection sock,
+ * SilcUInt32 header_len,
+ * SilcUInt32 pad_len,
+ * SilcUInt32 data_len,
+ * SilcHmac hmac,
+ * const SilcBuffer packet);
*
* DESCRIPTION
*
- * Prepare outgoing data buffer for packet sending. This moves the data
- * area so that new packet may be added into it. If needed this allocates
- * more space to the buffer. This handles directly the connection's
- * outgoing buffer in SilcSocketConnection object.
+ * This function can be used to prepare the outgoing data buffer in
+ * the socket connection specified by `sock' for packet sending.
+ * This is used internally by packet sending routines, but application
+ * may call this if it doesn't call silc_packet_assemble function.
+ * If that function is called then application must not call this since
+ * that function calls this internally.
+ *
+ * This returns the prepared data area into the `packet' pointer provided
+ * caller, which can be used then to add data to it, and later encrypt
+ * it. The `packet' includes reference to the socket connection's
+ * outgoing buffer.
*
***/
-void silc_packet_send_prepare(SilcSocketConnection sock,
- uint32 header_len,
- uint32 padlen,
- uint32 data_len);
+bool silc_packet_send_prepare(SilcSocketConnection sock,
+ SilcUInt32 header_len,
+ SilcUInt32 pad_len,
+ SilcUInt32 data_len,
+ SilcHmac hmac,
+ const SilcBuffer packet);
/****f* silccore/SilcPacketAPI/silc_packet_receive
*
***/
int silc_packet_receive(SilcSocketConnection sock);
-/****f* silccore/SilcPacketAPI/silc_packet_decrypt
- *
- * SYNOPSIS
- *
- * int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- * SilcBuffer buffer, SilcPacketContext *packet,
- * SilcPacketCheckDecrypt check_packet,
- * void *context);
- *
- * DESCRIPTION
- *
- * Decrypts a packet. This assumes that typical SILC packet is the
- * packet to be decrypted and thus checks for normal and special SILC
- * packets and can handle both of them. This also computes and checks
- * the HMAC of the packet. If any other special or customized decryption
- * processing is required this function cannot be used. This returns
- * -1 on error, 0 when packet is normal packet and 1 when the packet
- * is special and requires special processing.
- *
- * The `check_packet' is a callback funtion that this function will
- * call. The callback relates to the checking whether the packet is
- * normal packet or special packet and how it should be processed. If
- * the callback return TRUE the packet is normal and FALSE if the packet
- * is special and requires special procesing.
- *
- ***/
-int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
- SilcBuffer buffer, SilcPacketContext *packet,
- SilcPacketCheckDecrypt check_packet,
- void *context);
-
/****f* silccore/SilcPacketAPI/silc_packet_receive_process
*
* SYNOPSIS
*
- * void silc_packet_receive_process(SilcSocketConnection sock,
+ * bool silc_packet_receive_process(SilcSocketConnection sock,
+ * bool local_is_router,
* SilcCipher cipher, SilcHmac hmac,
* SilcPacketParserCallback parser,
- * void *context);
+ * void *parser_context);
*
* DESCRIPTION
*
- * Processes the received data. This checks the received data and
- * calls parser callback that handles the actual packet decryption
- * and parsing. If more than one packet was received this calls the
- * parser multiple times. The parser callback will get context
- * SilcPacketParserContext that includes the packet and the `context'
- * sent to this function.
+ * Processes and decrypts the incoming data, and calls parser callback
+ * for each received packet that will handle the actual packet parsing.
+ * If more than one packet was received this calls the parser multiple
+ * times. The parser callback will get context SilcPacketParserContext
+ * that includes the packet and the `parser_context' sent to this
+ * function.
+ *
+ * The `local_is_router' indicates whether the caller is router server
+ * in which case the receiving process of a certain packet types may
+ * be special. Normal server and client must set it to FALSE. The
+ * SilcPacketParserContext will indicate also whether the received
+ * packet was normal or special packet.
*
***/
-void silc_packet_receive_process(SilcSocketConnection sock,
+bool silc_packet_receive_process(SilcSocketConnection sock,
+ bool local_is_router,
SilcCipher cipher, SilcHmac hmac,
+ SilcUInt32 sequence,
SilcPacketParserCallback parser,
- void *context);
+ void *parser_context);
/****f* silccore/SilcPacketAPI/silc_packet_parse
*
* buffer is parsed, not head or tail sections.
*
***/
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx);
+SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher);
/****f* silccore/SilcPacketAPI/silc_packet_parse_special
*
* and parses the header and padding area only.
*
***/
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx);
+SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
+ SilcCipher cipher);
/****f* silccore/SilcPacketAPI/silc_packet_context_alloc
*