/*

  id.c

  Author: Pekka Riikonen <priikone@poseidon.pspt.fi>

  Copyright (C) 1997 - 2001 Pekka Riikonen

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
  
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

*/
/* $Id: silcid.c,v 1.8 2002/03/24 14:18:42 priikone Exp $ */

#include "silcincludes.h"
#include "silcid.h"

/* ID lengths (in bytes) without the IP address part */
#define ID_SERVER_LEN_PART      4
#define ID_CLIENT_LEN_PART      CLIENTID_HASH_LEN + 1
#define ID_CHANNEL_LEN_PART     4

/******************************************************************************

                                ID Payload

******************************************************************************/

struct SilcIDPayloadStruct {
  SilcIdType type;
  SilcUInt16 len;
  unsigned char *id;
};

/* Parses buffer and return ID payload into payload structure */

SilcIDPayload silc_id_payload_parse(const unsigned char *payload,
				    SilcUInt32 payload_len)
{
  SilcBufferStruct buffer;
  SilcIDPayload newp;
  int ret;

  SILC_LOG_DEBUG(("Parsing ID payload"));

  silc_buffer_set(&buffer, (unsigned char *)payload, payload_len);
  newp = silc_calloc(1, sizeof(*newp));
  if (!newp)
    return NULL;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_SHORT(&newp->type),
			     SILC_STR_UI_SHORT(&newp->len),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  silc_buffer_pull(&buffer, 4);

  if (newp->len > buffer.len || newp->len > SILC_PACKET_MAX_ID_LEN)
    goto err;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_XNSTRING_ALLOC(&newp->id, newp->len),
			     SILC_STR_END);
  if (ret == -1)
    goto err;

  silc_buffer_push(&buffer, 4);

  return newp;

 err:
  silc_free(newp);
  return NULL;
}

/* Return the ID directly from the raw payload data. */

void *silc_id_payload_parse_id(const unsigned char *data, SilcUInt32 len,
			       SilcIdType *ret_type)
{
  SilcBufferStruct buffer;
  SilcIdType type;
  SilcUInt16 idlen;
  unsigned char *id_data;
  int ret;
  void *id;

  silc_buffer_set(&buffer, (unsigned char *)data, len);
  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_SHORT(&type),
			     SILC_STR_UI_SHORT(&idlen),
			     SILC_STR_END);
  if (ret == -1)
    return NULL;

  silc_buffer_pull(&buffer, 4);

  if (idlen > buffer.len || idlen > SILC_PACKET_MAX_ID_LEN)
    return NULL;

  ret = silc_buffer_unformat(&buffer,
			     SILC_STR_UI_XNSTRING(&id_data, idlen),
			     SILC_STR_END);
  if (ret == -1)
    return NULL;

  id = silc_id_str2id(id_data, idlen, type);

  if (ret_type)
    *ret_type = type;

  return id;
}

/* Encodes ID Payload */

SilcBuffer silc_id_payload_encode(const void *id, SilcIdType type)
{
  SilcBuffer buffer;
  unsigned char *id_data;
  SilcUInt32 len;

  id_data = silc_id_id2str(id, type);
  len = silc_id_get_len(id, type);
  buffer = silc_id_payload_encode_data((const unsigned char *)id_data,
				       len, type);
  silc_free(id_data);
  return buffer;
}

SilcBuffer silc_id_payload_encode_data(const unsigned char *id,
				       SilcUInt32 id_len, SilcIdType type)
{
  SilcBuffer buffer;

  SILC_LOG_DEBUG(("Encoding %s ID payload",
		  type == SILC_ID_CLIENT ? "Client" :
		  type == SILC_ID_SERVER ? "Server" : "Channel"));

  buffer = silc_buffer_alloc_size(4 + id_len);
  if (!buffer)
    return NULL;
  silc_buffer_format(buffer,
		     SILC_STR_UI_SHORT(type),
		     SILC_STR_UI_SHORT(id_len),
		     SILC_STR_UI_XNSTRING(id, id_len),
		     SILC_STR_END);
  return buffer;
}

/* Free ID Payload */

void silc_id_payload_free(SilcIDPayload payload)
{
  if (payload) {
    silc_free(payload->id);
    silc_free(payload);
  }
}

/* Get ID type */

SilcIdType silc_id_payload_get_type(SilcIDPayload payload)
{
  return payload ? payload->type : 0;
}

/* Get ID */

void *silc_id_payload_get_id(SilcIDPayload payload)
{
  return payload ? silc_id_str2id(payload->id, payload->len,
                                  payload->type) : NULL;
}

/* Get raw ID data. Data is duplicated. */

unsigned char *silc_id_payload_get_data(SilcIDPayload payload)
{
  if (!payload)
    return NULL;

  return silc_memdup(payload->id, payload->len);
}

/* Get length of ID */

SilcUInt32 silc_id_payload_get_len(SilcIDPayload payload)
{
  return payload ? payload->len : 0;
}

/* Converts ID to string. */

unsigned char *silc_id_id2str(const void *id, SilcIdType type)
{
  unsigned char *ret_id;
  SilcServerID *server_id;
  SilcClientID *client_id;
  SilcChannelID *channel_id;
  SilcUInt32 id_len = silc_id_get_len(id, type);

  switch(type) {
  case SILC_ID_SERVER:
    server_id = (SilcServerID *)id;
    ret_id = silc_calloc(id_len, sizeof(unsigned char));
    if (!ret_id)
      return NULL;
    memcpy(ret_id, server_id->ip.data, server_id->ip.data_len);
    SILC_PUT16_MSB(server_id->port, &ret_id[server_id->ip.data_len]);
    SILC_PUT16_MSB(server_id->rnd, &ret_id[server_id->ip.data_len + 2]);
    return ret_id;
    break;
  case SILC_ID_CLIENT:
    client_id = (SilcClientID *)id;
    ret_id = silc_calloc(id_len, sizeof(unsigned char));
    if (!ret_id)
      return NULL;
    memcpy(ret_id, client_id->ip.data, client_id->ip.data_len);
    ret_id[client_id->ip.data_len] = client_id->rnd;
    memcpy(&ret_id[client_id->ip.data_len + 1], client_id->hash, 
	   CLIENTID_HASH_LEN);
    return ret_id;
    break;
  case SILC_ID_CHANNEL:
    channel_id = (SilcChannelID *)id;
    ret_id = silc_calloc(id_len, sizeof(unsigned char));
    if (!ret_id)
      return NULL;
    memcpy(ret_id, channel_id->ip.data, channel_id->ip.data_len);
    SILC_PUT16_MSB(channel_id->port, &ret_id[channel_id->ip.data_len]);
    SILC_PUT16_MSB(channel_id->rnd, &ret_id[channel_id->ip.data_len + 2]);
    return ret_id;
    break;
  }

  return NULL;
}

/* Converts string to a ID */

void *silc_id_str2id(const unsigned char *id, SilcUInt32 id_len, 
		     SilcIdType type)
{

  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id;

      if (id_len != ID_SERVER_LEN_PART + 4 &&
	  id_len != ID_SERVER_LEN_PART + 16)
	return NULL;

      server_id = silc_calloc(1, sizeof(*server_id));
      if (!server_id)
	return NULL;
      memcpy(server_id->ip.data, id, (id_len > ID_SERVER_LEN_PART + 4 ?
				      16 : 4));
      server_id->ip.data_len = (id_len > ID_SERVER_LEN_PART + 4 ? 16 : 4);
      SILC_GET16_MSB(server_id->port, &id[server_id->ip.data_len]);
      SILC_GET16_MSB(server_id->rnd, &id[server_id->ip.data_len + 2]);
      return server_id;
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id;

      if (id_len != ID_CLIENT_LEN_PART + 4 &&
	  id_len != ID_CLIENT_LEN_PART + 16)
	return NULL;

      client_id = silc_calloc(1, sizeof(*client_id));
      if (!client_id)
	return NULL;
      memcpy(client_id->ip.data, id, (id_len > ID_CLIENT_LEN_PART + 4 ?
				      16 : 4));
      client_id->ip.data_len = (id_len > ID_CLIENT_LEN_PART + 4 ? 16 : 4);
      client_id->rnd = id[client_id->ip.data_len];
      memcpy(client_id->hash, &id[client_id->ip.data_len + 1], 
	     CLIENTID_HASH_LEN);
      return client_id;
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id;

      if (id_len != ID_CHANNEL_LEN_PART + 4 &&
	  id_len != ID_CHANNEL_LEN_PART + 16)
	return NULL;

      channel_id = silc_calloc(1, sizeof(*channel_id));
      if (!channel_id)
	return NULL;
      memcpy(channel_id->ip.data, id, (id_len > ID_CHANNEL_LEN_PART + 4 ?
				       16 : 4));
      channel_id->ip.data_len = (id_len > ID_CHANNEL_LEN_PART + 4 ? 16 : 4);
      SILC_GET16_MSB(channel_id->port, &id[channel_id->ip.data_len]);
      SILC_GET16_MSB(channel_id->rnd, &id[channel_id->ip.data_len + 2]);
      return channel_id;
    }
    break;
  }

  return NULL;
}

/* Returns length of the ID */

SilcUInt32 silc_id_get_len(const void *id, SilcIdType type)
{
  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id = (SilcServerID *)id;
      return ID_SERVER_LEN_PART + server_id->ip.data_len;
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id = (SilcClientID *)id;
      return ID_CLIENT_LEN_PART + client_id->ip.data_len;
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id = (SilcChannelID *)id;
      return ID_CHANNEL_LEN_PART + channel_id->ip.data_len;
    }
    break;
  }

  return 0;
}

/* Duplicate ID data */

void *silc_id_dup(const void *id, SilcIdType type)
{
  switch(type) {
  case SILC_ID_SERVER:
    {
      SilcServerID *server_id = (SilcServerID *)id;
      return silc_memdup(server_id, sizeof(*server_id));
    }
    break;
  case SILC_ID_CLIENT:
    {
      SilcClientID *client_id = (SilcClientID *)id;
      return silc_memdup(client_id, sizeof(*client_id));
    }
    break;
  case SILC_ID_CHANNEL:
    {
      SilcChannelID *channel_id = (SilcChannelID *)id;
      return silc_memdup(channel_id, sizeof(*channel_id));
    }
    break;
  }

  return NULL;
}
