/*

  client.c

  Author: Pekka Riikonen <priikone@silcnet.org>

  Copyright (C) 1997 - 2002 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; version 2 of the License.
  
  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.

*/
/* $Id$ */

#include "module.h"

#include "net-nonblock.h"
#include "net-sendbuffer.h"
#include "signals.h"
#include "servers.h"
#include "commands.h"
#include "levels.h"
#include "modules.h"
#include "rawlog.h"
#include "misc.h"
#include "settings.h"

#include "channels-setup.h"

#include "silc-servers.h"
#include "silc-channels.h"
#include "silc-queries.h"
#include "silc-nicklist.h"
#include "window-item-def.h"

#include "fe-common/core/printtext.h"
#include "fe-common/core/keyboard.h"

/* Lists supported ciphers */

void silc_client_list_ciphers()
{
  char *ciphers = silc_cipher_get_supported();
  fprintf(stdout, "%s\n", ciphers);
  silc_free(ciphers);
}

/* Lists supported hash functions */

void silc_client_list_hash_funcs()
{
  char *hash = silc_hash_get_supported();
  fprintf(stdout, "%s\n", hash);
  silc_free(hash);
}

/* Lists supported hash functions */

void silc_client_list_hmacs()
{
  char *hash = silc_hmac_get_supported();
  fprintf(stdout, "%s\n", hash);
  silc_free(hash);
}

/* Lists supported PKCS algorithms */

void silc_client_list_pkcs()
{
  char *pkcs = silc_pkcs_get_supported();
  fprintf(stdout, "%s\n", pkcs);
  silc_free(pkcs);
}

/* Displays input prompt on command line and takes input data from user */

char *silc_client_get_input(const char *prompt)
{
  char input[2048];
  int fd;

  fd = open("/dev/tty", O_RDONLY);
  if (fd < 0) {
    fprintf(stderr, "silc: %s\n", strerror(errno));
    return NULL;
  }

  memset(input, 0, sizeof(input));

  printf("%s", prompt);
  fflush(stdout);

  if ((read(fd, input, sizeof(input))) < 0) {
    fprintf(stderr, "silc: %s\n", strerror(errno));
    return NULL;
  }

  if (strlen(input) <= 1)
    return NULL;

  if (strchr(input, '\n'))
    *strchr(input, '\n') = '\0';

  return strdup(input);
}

/* Returns identifier string for public key generation. */

char *silc_client_create_identifier()
{
  char *username = NULL, *realname = NULL;
  char *hostname, email[256];
  char *ident;
  
  /* Get realname */
  realname = silc_get_real_name();

  /* Get hostname */
  hostname = silc_net_localhost();
  if (!hostname)
    return NULL;

  /* Get username (mandatory) */
  username = silc_get_username();
  if (!username)
    return NULL;

  /* Create default email address, whether it is right or not */
  snprintf(email, sizeof(email), "%s@%s", username, hostname);

  ident = silc_pkcs_encode_identifier(username, hostname, realname, email,
				      NULL, NULL);
  if (realname)
    silc_free(realname);
  silc_free(hostname);
  silc_free(username);

  return ident;
}

/* Creates new public key and private key pair. This is used only
   when user wants to create new key pair from command line. */

int silc_client_create_key_pair(char *pkcs_name, int bits,
				char *public_key, char *private_key,
				char *identifier, 
				SilcPublicKey *ret_pub_key,
				SilcPrivateKey *ret_prv_key)
{
  SilcPKCS pkcs;
  SilcPublicKey pub_key;
  SilcPrivateKey prv_key;
  SilcRng rng;
  unsigned char *key;
  SilcUInt32 key_len;
  char line[256];
  char *pkfile = NULL, *prvfile = NULL;

  if (!pkcs_name || !public_key || !private_key)
    printf("\
New pair of keys will be created.  Please, answer to following questions.\n\
");

  if (!pkcs_name) {
  again_name:
    pkcs_name = 
      silc_client_get_input("PKCS name (l to list names) [rsa]: ");
    if (!pkcs_name)
      pkcs_name = strdup("rsa");

    if (*pkcs_name == 'l' || *pkcs_name == 'L') {
      silc_client_list_pkcs();
      silc_free(pkcs_name);
      goto again_name;
    }
  }

  if (!silc_pkcs_is_supported(pkcs_name)) {
    fprintf(stderr, "Unknown PKCS `%s'", pkcs_name);
    return FALSE;
  }

  if (!bits) {
    char *length = NULL;
    length = 
      silc_client_get_input("Key length in bits [1024]: ");
    if (!length)
      bits = 1024;
    else
      bits = atoi(length);
  }

  if (!identifier) {
    char *def = silc_client_create_identifier();

    memset(line, 0, sizeof(line));
    if (def)
      snprintf(line, sizeof(line), "Identifier [%s]: ", def);
    else
      snprintf(line, sizeof(line),
	       "Identifier (eg. UN=jon, HN=jon.dummy.com, "
	       "RN=Jon Johnson, E=jon@dummy.com): ");

    while (!identifier) {
      identifier = silc_client_get_input(line);
      if (!identifier && def)
	identifier = strdup(def);
    }

    if (def)
      silc_free(def);
  }

  rng = silc_rng_alloc();
  silc_rng_init(rng);
  silc_rng_global_init(rng);

  if (!public_key) {
    memset(line, 0, sizeof(line));
    snprintf(line, sizeof(line), "Public key filename [%s] ", 
	     SILC_CLIENT_PUBLIC_KEY_NAME);
    pkfile = silc_client_get_input(line);
    if (!pkfile)
      pkfile = SILC_CLIENT_PUBLIC_KEY_NAME;
  } else {
    pkfile = public_key;
  }

  if (!private_key) {
    memset(line, 0, sizeof(line));
    snprintf(line, sizeof(line), "Public key filename [%s] ", 
	     SILC_CLIENT_PRIVATE_KEY_NAME);
    prvfile = silc_client_get_input(line);
    if (!prvfile)
      prvfile = SILC_CLIENT_PRIVATE_KEY_NAME;
  } else {
    prvfile = private_key;
  }

  /* Generate keys */
  silc_pkcs_alloc(pkcs_name, &pkcs);
  pkcs->pkcs->init(pkcs->context, bits, rng);

  /* Save public key into file */
  key = silc_pkcs_get_public_key(pkcs, &key_len);
  pub_key = silc_pkcs_public_key_alloc(pkcs->pkcs->name, identifier,
				       key, key_len);
  silc_pkcs_save_public_key(pkfile, pub_key, SILC_PKCS_FILE_PEM);
  if (ret_pub_key)
    *ret_pub_key = pub_key;

  memset(key, 0, sizeof(key_len));
  silc_free(key);

  /* Save private key into file */
  key = silc_pkcs_get_private_key(pkcs, &key_len);
  prv_key = silc_pkcs_private_key_alloc(pkcs->pkcs->name, key, key_len);

  silc_pkcs_save_private_key(prvfile, prv_key, NULL, SILC_PKCS_FILE_BIN);
  if (ret_prv_key)
    *ret_prv_key = prv_key;

  printf("Public key has been saved into `%s'.\n", pkfile);
  printf("Private key has been saved into `%s'.\n", prvfile);
  printf("Press <Enter> to continue...\n");
  getchar();

  memset(key, 0, sizeof(key_len));
  silc_free(key);

  silc_rng_free(rng);
  silc_pkcs_free(pkcs);

  return TRUE;
}

/* This checks stats for various SILC files and directories. First it 
   checks if ~/.silc directory exist and is owned by the correct user. If 
   it doesn't exist, it will create the directory. After that it checks if
   user's Public and Private key files exists and that they aren't expired.
   If they doesn't exist or they are expired, they will be (re)created
   after return. */

int silc_client_check_silc_dir()
{
  char filename[256], file_public_key[256], file_private_key[256];
  char servfilename[256], clientfilename[256];
  char *identifier;
  struct stat st;
  struct passwd *pw;
  int firstime = FALSE;
  time_t curtime, modtime;

  SILC_LOG_DEBUG(("Checking ~./silc directory"));

  memset(filename, 0, sizeof(filename));
  memset(file_public_key, 0, sizeof(file_public_key));
  memset(file_private_key, 0, sizeof(file_private_key));

  identifier = silc_client_create_identifier();

  pw = getpwuid(getuid());
  if (!pw) {
    fprintf(stderr, "silc: %s\n", strerror(errno));
    if (identifier)
      silc_free(identifier);
    return FALSE;
  }

  /* We'll take home path from /etc/passwd file to be sure. */
  snprintf(filename, sizeof(filename) - 1, "%s/.silc/", pw->pw_dir);
  snprintf(servfilename, sizeof(servfilename) - 1, "%s/.silc/serverkeys", 
	   pw->pw_dir);
  snprintf(clientfilename, sizeof(clientfilename) - 1, "%s/.silc/clientkeys", 
	   pw->pw_dir);

  /*
   * Check ~/.silc directory
   */
  if ((stat(filename, &st)) == -1) {
    /* If dir doesn't exist */
    if (errno == ENOENT) {
      if (pw->pw_uid == geteuid()) {
	if ((mkdir(filename, 0755)) == -1) {
	  fprintf(stderr, "Couldn't create `%s' directory\n", filename);
	  return FALSE;
	}

	/* Directory was created. First time running SILC */
	firstime = TRUE;
      } else {
	fprintf(stderr, "Couldn't create `%s' directory due to a wrong uid!\n",
		filename);
	return FALSE;
      }
    } else {
      fprintf(stderr, "%s\n", strerror(errno));
      return FALSE;
    }
  } else {
    
    /* Check the owner of the dir */
    if (st.st_uid != 0 && st.st_uid != pw->pw_uid) { 
      fprintf(stderr, "You don't seem to own `%s' directory\n",
	      filename);
      return FALSE;
    }
    
#if 0
    /* Check the permissions of the dir */
    if ((st.st_mode & 0777) != 0755) {
      if ((chmod(filename, 0755)) == -1) {
	fprintf(stderr, "Permissions for `%s' directory must be 0755\n", 
		filename);
	return FALSE;
      }
    }
#endif
  }

  /*
   * Check ~./silc/serverkeys directory
   */
  if ((stat(servfilename, &st)) == -1) {
    /* If dir doesn't exist */
    if (errno == ENOENT) {
      if (pw->pw_uid == geteuid()) {
	if ((mkdir(servfilename, 0755)) == -1) {
	  fprintf(stderr, "Couldn't create `%s' directory\n", servfilename);
	  return FALSE;
	}
      } else {
	fprintf(stderr, "Couldn't create `%s' directory due to a wrong uid!\n",
		servfilename);
	return FALSE;
      }
    } else {
      fprintf(stderr, "%s\n", strerror(errno));
      return FALSE;
    }
  }
  
  /*
   * Check ~./silc/clientkeys directory
   */
  if ((stat(clientfilename, &st)) == -1) {
    /* If dir doesn't exist */
    if (errno == ENOENT) {
      if (pw->pw_uid == geteuid()) {
	if ((mkdir(clientfilename, 0755)) == -1) {
	  fprintf(stderr, "Couldn't create `%s' directory\n", clientfilename);
	  return FALSE;
	}
      } else {
	fprintf(stderr, "Couldn't create `%s' directory due to a wrong uid!\n",
		clientfilename);
	return FALSE;
      }
    } else {
      fprintf(stderr, "%s\n", strerror(errno));
      return FALSE;
    }
  }
  
  /*
   * Check Public and Private keys
   */
  snprintf(file_public_key, sizeof(file_public_key) - 1, "%s%s", 
	   filename, SILC_CLIENT_PUBLIC_KEY_NAME);
  snprintf(file_private_key, sizeof(file_private_key) - 1, "%s%s", 
	   filename, SILC_CLIENT_PRIVATE_KEY_NAME);
  
  /* If running SILC first time */
  if (firstime) {
    fprintf(stdout, "Running SILC for the first time\n");
    silc_client_create_key_pair(SILC_CLIENT_DEF_PKCS, 
				SILC_CLIENT_DEF_PKCS_LEN,
				file_public_key, file_private_key, 
				identifier, NULL, NULL);
    return TRUE;
  }
  
  if ((stat(file_public_key, &st)) == -1) {
    /* If file doesn't exist */
    if (errno == ENOENT) {
      fprintf(stdout, "Your public key doesn't exist\n");
      silc_client_create_key_pair(SILC_CLIENT_DEF_PKCS, 
				  SILC_CLIENT_DEF_PKCS_LEN,
				  file_public_key, 
				  file_private_key, identifier, NULL, NULL);
    } else {
      fprintf(stderr, "%s\n", strerror(errno));
      return FALSE;
    }
  }

  if ((stat(file_private_key, &st)) == -1) {
    /* If file doesn't exist */
    if (errno == ENOENT) {
      fprintf(stdout, "Your private key doesn't exist\n");
      silc_client_create_key_pair(SILC_CLIENT_DEF_PKCS, 
				  SILC_CLIENT_DEF_PKCS_LEN,
				  file_public_key, 
				  file_private_key, identifier, NULL, NULL);
    } else {
      fprintf(stderr, "%s\n", strerror(errno));
      return FALSE;
    }
  }
    
  /* Check the owner of the public key */
  if (st.st_uid != 0 && st.st_uid != pw->pw_uid) { 
    fprintf(stderr, "You don't seem to own your public key!?\n");
    return FALSE;
  }
  
  /* Check the owner of the private key */
  if (st.st_uid != 0 && st.st_uid != pw->pw_uid) { 
    fprintf(stderr, "You don't seem to own your private key!?\n");
    return FALSE;
  }
    
  /* Check the permissions for the private key */
  if ((st.st_mode & 0777) != 0600) {
    fprintf(stderr, "Wrong permissions in your private key file `%s'!\n"
	    "Trying to change them ... ", file_private_key);
    if ((chmod(file_private_key, 0600)) == -1) {
      fprintf(stderr,
	      "Failed to change permissions for private key file!\n" 
	      "Permissions for your private key file must be 0600.\n");
      return FALSE;
    }
    fprintf(stderr, "Done.\n\n");
  }

  /* See if the key has expired. */
  modtime = st.st_mtime;	/* last modified */
  curtime = time(0) - modtime;
    
  /* 86400 is seconds in a day. */
  if (curtime >= (86400 * SILC_CLIENT_KEY_EXPIRES)) {
    fprintf(stdout, 
	    "--------------------------------------------------\n"
	    "Your private key has expired and needs to be\n" 
	    "recreated.  This will be done automatically now.\n"
	    "Your new key will expire in %d days from today.\n"
	    "--------------------------------------------------\n",
	    SILC_CLIENT_KEY_EXPIRES);

    silc_client_create_key_pair(SILC_CLIENT_DEF_PKCS, 
				SILC_CLIENT_DEF_PKCS_LEN,
				file_public_key, 
				file_private_key, identifier, NULL, NULL);
  }
  
  if (identifier)
    silc_free(identifier);

  return TRUE;
}

/* Loads public and private key from files. */

int silc_client_load_keys(SilcClient client)
{
  char filename[256];
  struct passwd *pw;

  SILC_LOG_DEBUG(("Loading public and private keys"));

  pw = getpwuid(getuid());
  if (!pw)
    return FALSE;

  memset(filename, 0, sizeof(filename));
  snprintf(filename, sizeof(filename) - 1, "%s/.silc/%s", 
	   pw->pw_dir, SILC_CLIENT_PRIVATE_KEY_NAME);

  if (silc_pkcs_load_private_key(filename, &client->private_key,
				 SILC_PKCS_FILE_BIN) == FALSE)
    if (silc_pkcs_load_private_key(filename, &client->private_key,
				   SILC_PKCS_FILE_PEM) == FALSE)
      return FALSE;

  memset(filename, 0, sizeof(filename));
  snprintf(filename, sizeof(filename) - 1, "%s/.silc/%s", 
	   pw->pw_dir, SILC_CLIENT_PUBLIC_KEY_NAME);

  if (silc_pkcs_load_public_key(filename, &client->public_key,
				SILC_PKCS_FILE_PEM) == FALSE)
    if (silc_pkcs_load_public_key(filename, &client->public_key,
				  SILC_PKCS_FILE_BIN) == FALSE)
      return FALSE;

  silc_pkcs_alloc(client->public_key->name, &client->pkcs);
  silc_pkcs_public_key_set(client->pkcs, client->public_key);
  silc_pkcs_private_key_set(client->pkcs, client->private_key);

  return TRUE;
}

/* Dumps the public key on screen. Used from the command line option. */

int silc_client_show_key(char *keyfile)
{
  SilcPublicKey public_key;
  SilcPublicKeyIdentifier ident;
  char *fingerprint, *babbleprint;
  unsigned char *pk;
  SilcUInt32 pk_len;
  SilcPKCS pkcs;
  int key_len = 0;

  if (silc_pkcs_load_public_key(keyfile, &public_key,
				SILC_PKCS_FILE_PEM) == FALSE)
    if (silc_pkcs_load_public_key(keyfile, &public_key,
				  SILC_PKCS_FILE_BIN) == FALSE) {
      fprintf(stderr, "Could not load public key file `%s'\n", keyfile);
      return FALSE;
    }

  ident = silc_pkcs_decode_identifier(public_key->identifier);

  pk = silc_pkcs_public_key_encode(public_key, &pk_len);
  fingerprint = silc_hash_fingerprint(NULL, pk, pk_len);
  babbleprint = silc_hash_babbleprint(NULL, pk, pk_len);

  if (silc_pkcs_alloc(public_key->name, &pkcs)) {
    key_len = silc_pkcs_public_key_set(pkcs, public_key);
    silc_pkcs_free(pkcs);
  }

  printf("Public key file    : %s\n", keyfile);
  printf("Algorithm          : %s\n", public_key->name);
  if (key_len)
    printf("Key length (bits)  : %d\n", key_len);
  if (ident->realname)
    printf("Real name          : %s\n", ident->realname);
  if (ident->username)
    printf("Username           : %s\n", ident->username);
  if (ident->host)
    printf("Hostname           : %s\n", ident->host);
  if (ident->email)
    printf("Email              : %s\n", ident->email);
  if (ident->org)
    printf("Organization       : %s\n", ident->org);
  if (ident->country)
    printf("Country            : %s\n", ident->country);
  printf("Fingerprint (SHA1) : %s\n", fingerprint); 
  printf("Babbleprint (SHA1) : %s\n", babbleprint); 

  fflush(stdout);

  silc_free(fingerprint);
  silc_free(babbleprint);
  silc_free(pk);
  silc_pkcs_public_key_free(public_key);
  silc_pkcs_free_identifier(ident);

  return TRUE;
}