/*
   BAREOS® - Backup Archiving REcovery Open Sourced

   Copyright (C) 2012-2012 Free Software Foundation Europe e.V.
   Copyright (C) 2011-2012 Planets Communications B.V.
   Copyright (C) 2013-2013 Bareos GmbH & Co. KG

   This program is Free Software; you can redistribute it and/or
   modify it under the terms of version three of the GNU Affero General Public
   License as published by the Free Software Foundation and included
   in the file 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
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.
*/
/*
 * Load and clear an SCSI encryption key used by a tape drive
 * using a lowlevel SCSI interface.
 *
 * Marco van Wieringen, March 2012
 */

#include "bareos.h"
#include "lib/crypto_cache.h"

static void usage()
{
   fprintf(stderr,
"\n"
"Usage: bscrypto <options> [<device_name>]\n"
"       -b              Perform base64 encoding of keydata\n"
"       -c              Clear encryption key\n"
"       -D <cachefile>  Dump content of given cachefile\n"
"       -d <nn>         Set debug level to <nn>\n"
"       -e              Show drive encryption status\n"
"       -g <keyfile>    Generate new encryption passphrase in keyfile\n"
"       -k <keyfile>    Show content of keyfile\n"
"       -p <cachefile>  Populate given cachefile with crypto keys\n"
"       -r <cachefile>  Reset expiry time for entries of given cachefile\n"
"       -s <keyfile>    Set encryption key loaded from keyfile\n"
"       -v              Show volume encryption status\n"
"       -w <keyfile>    Wrap/Unwrap the key using RFC3394 aes-(un)wrap\n"
"                       using the key in keyfile as a Key Encryption Key\n"
"       -?              print this message.\n"
"\n"
"       A keyfile named - is either stdin or stdout depending on the option\n"
"\n");
}

int main(int argc, char *const *argv)
{
   int retval = 0;
   int ch, kfd, length;
   bool base64_transform = false,
        clear_encryption = false,
        dump_cache = false,
        drive_encryption_status = false,
        generate_passphrase = false,
        populate_cache = false,
        reset_cache = false,
        set_encryption = false,
        show_keydata = false,
        volume_encryption_status = false,
        wrapped_keys = false;
   char *keyfile = NULL;
   char *cache_file = NULL;
   char *wrap_keyfile = NULL;
   char keydata[64];
   char wrapdata[64];

   setlocale(LC_ALL, "");
   bindtextdomain("bareos", LOCALEDIR);
   textdomain("bareos");

   while ((ch = getopt(argc, argv, "bcD:d:eg:k:p:r:s:vw:?")) != -1) {
      switch (ch) {
      case 'b':
         base64_transform = true;
         break;

      case 'c':
         clear_encryption = true;
         break;

      case 'D':
         dump_cache = true;
         cache_file = bstrdup(optarg);
         break;

      case 'd':
         debug_level = atoi(optarg);
         if (debug_level <= 0) {
            debug_level = 1;
         }
         break;

      case 'e':
         drive_encryption_status = true;
         break;

      case 'g':
         generate_passphrase = true;
         if (keyfile) {
            usage();
            goto bail_out;
         }
         keyfile = bstrdup(optarg);
         break;

      case 'k':
         show_keydata = true;
         if (keyfile) {
            usage();
            goto bail_out;
         }
         keyfile = bstrdup(optarg);
         break;

      case 'p':
         populate_cache = true;
         cache_file = bstrdup(optarg);
         break;

      case 'r':
         reset_cache = true;
         cache_file = bstrdup(optarg);
         break;

      case 's':
         set_encryption = true;
         if (keyfile) {
            usage();
            goto bail_out;
         }
         keyfile = bstrdup(optarg);
         break;

      case 'v':
         volume_encryption_status = true;
         break;

      case 'w':
         wrapped_keys = true;
         wrap_keyfile = bstrdup(optarg);
         break;

      case '?':
      default:
         usage();
         goto bail_out;

      }
   }

   argc -= optind;
   argv += optind;

   if (!generate_passphrase && !show_keydata && !dump_cache && !populate_cache && !reset_cache && argc < 1) {
      fprintf(stderr, _("Missing device_name argument for this option\n"));
      usage();
      retval = 1;
      goto bail_out;
   }

   if (generate_passphrase && show_keydata) {
      fprintf(stderr, _("Either use -g or -k not both\n"));
      retval = 1;
      goto bail_out;
   }

   if (clear_encryption && set_encryption) {
      fprintf(stderr, _("Either use -c or -s not both\n"));
      retval = 1;
      goto bail_out;
   }

   if ((clear_encryption ||
        set_encryption) &&
       (drive_encryption_status ||
        volume_encryption_status)) {
      fprintf(stderr, _("Either set or clear the crypto key or ask for status not both\n"));
      retval = 1;
      goto bail_out;
   }

   if ((clear_encryption ||
        set_encryption ||
        drive_encryption_status ||
        volume_encryption_status) &&
       (generate_passphrase ||
        show_keydata ||
        dump_cache ||
        populate_cache ||
        reset_cache)) {
      fprintf(stderr, _("Don't mix operations which are incompatible "
                        "e.g. generate/show vs set/clear etc.\n"));
      retval = 1;
      goto bail_out;
   }

   OSDependentInit();
   init_msg(NULL, NULL);

   if (dump_cache) {
      /*
       * Load any keys currently in the cache.
       */
      read_crypto_cache(cache_file);

      /*
       * Dump the content of the cache.
       */
      dump_crypto_cache(1);

      flush_crypto_cache();
      goto bail_out;
   }

   if (populate_cache) {
      char *VolumeName, *EncrKey;
      char new_cache_entry[256];

      /*
       * Load any keys currently in the cache.
       */
      read_crypto_cache(cache_file);

      /*
       * Read new entries from stdin and parse them to update
       * the cache.
       */
      fprintf(stdout, _("Enter cache entrie(s) (close with ^D): "));
      fflush(stdout);

      memset(new_cache_entry, 0, sizeof(new_cache_entry));
      while (read(1, new_cache_entry, sizeof(new_cache_entry)) > 0) {
         strip_trailing_junk(new_cache_entry);

         /*
          * Try to parse the entry.
          */
         VolumeName = new_cache_entry;
         EncrKey = strchr(new_cache_entry, '\t');
         if (!EncrKey) {
            break;
         }

         *EncrKey++ = '\0';
         update_crypto_cache(VolumeName, EncrKey);
         memset(new_cache_entry, 0, sizeof(new_cache_entry));
      }

      /*
       * Write out the new cache entries.
       */
      write_crypto_cache(cache_file);

      flush_crypto_cache();
      goto bail_out;
   }

   if (reset_cache) {
      /*
       * Load any keys currently in the cache.
       */
      read_crypto_cache(cache_file);

      /*
       * Reset all entries.
       */
      reset_crypto_cache();

      /*
       * Write out the new cache entries.
       */
      write_crypto_cache(cache_file);

      flush_crypto_cache();
      goto bail_out;
   }

   memset(keydata, 0, sizeof(keydata));
   memset(wrapdata, 0, sizeof(wrapdata));

   if (wrapped_keys) {
      /*
       * Read the key bits from the keyfile.
       * - == stdin
       */
      if (bstrcmp(wrap_keyfile, "-")) {
         kfd = 0;
         fprintf(stdout, _("Enter Key Encryption Key: "));
         fflush(stdout);
      } else {
         kfd = open(wrap_keyfile, O_RDONLY);
         if (kfd < 0) {
            fprintf(stderr, _("Cannot open keyfile %s\n"), wrap_keyfile);
            retval = 1;
            goto bail_out;
         }
      }
      read(kfd, wrapdata, sizeof(wrapdata));
      if (kfd > 0) {
         close(kfd);
      }
      strip_trailing_junk(wrapdata);
      Dmsg1(10, "Wrapped keydata = %s\n", wrapdata);
   }

   /*
    * Generate a new passphrase allow it to be wrapped using the given wrapkey
    * and base64 if specified or when wrapped.
    */
   if (generate_passphrase) {
      int cnt;
      char *passphrase;

      passphrase = generate_crypto_passphrase(DEFAULT_PASSPHRASE_LENGTH);
      if (!passphrase) {
         retval = 1;
         goto bail_out;
      }

      Dmsg1(10, "Generated passphrase = %s\n", passphrase);

      /*
       * See if we need to wrap the passphrase.
       */
      if (wrapped_keys) {
         char *wrapped_passphrase;

         length = DEFAULT_PASSPHRASE_LENGTH + 8;
         wrapped_passphrase = (char *)malloc(length);
         memset(wrapped_passphrase, 0, length);
         aes_wrap((unsigned char *)wrapdata,
                  DEFAULT_PASSPHRASE_LENGTH / 8,
                  (unsigned char *)passphrase,
                  (unsigned char *)wrapped_passphrase);

         free(passphrase);
         passphrase = wrapped_passphrase;
      } else {
         length = DEFAULT_PASSPHRASE_LENGTH;
      }

      /*
       * See where to write the key.
       * - == stdout
       */
      if (bstrcmp(keyfile, "-")) {
         kfd = 1;
      } else {
         kfd = open(keyfile, O_WRONLY | O_CREAT, 0644);
         if (kfd < 0) {
            fprintf(stderr, _("Cannot open keyfile %s\n"), keyfile);
            free(passphrase);
            retval = 1;
            goto bail_out;
         }
      }

      if (base64_transform || wrapped_keys) {
         cnt = bin_to_base64(keydata, sizeof(keydata), passphrase, length, true);
         if (write(kfd, keydata, cnt) != cnt) {
            fprintf(stderr, _("Failed to write %d bytes to keyfile %s\n"), cnt, keyfile);
         }
      } else {
         cnt = DEFAULT_PASSPHRASE_LENGTH;
         if (write(kfd, passphrase, cnt) != cnt) {
            fprintf(stderr, _("Failed to write %d bytes to keyfile %s\n"), cnt, keyfile);
         }
      }

      Dmsg1(10, "Keydata = %s\n", keydata);

      if (kfd > 1) {
         close(kfd);
      } else {
         write(kfd, "\n", 1);
      }
      free(passphrase);
      goto bail_out;
   }

   if (show_keydata) {
      char *passphrase;

      /*
       * Read the key bits from the keyfile.
       * - == stdin
       */
      if (bstrcmp(keyfile, "-")) {
         kfd = 0;
         fprintf(stdout, _("Enter Encryption Key: "));
         fflush(stdout);
      } else {
         kfd = open(keyfile, O_RDONLY);
         if (kfd < 0) {
            fprintf(stderr, _("Cannot open keyfile %s\n"), keyfile);
            retval = 1;
            goto bail_out;
         }
      }
      read(kfd, keydata, sizeof(keydata));
      if (kfd > 0) {
         close(kfd);
      }
      strip_trailing_junk(keydata);
      Dmsg1(10, "Keydata = %s\n", keydata);

      /*
       * See if we need to unwrap the passphrase.
       */
      if (wrapped_keys) {
         char *wrapped_passphrase;
         /*
          * A wrapped key is base64 encoded after it was wrapped so first
          * convert it from base64 to bin. As we first go from base64 to bin
          * and the base64_to_bin has a check if the decoded string will fit
          * we need to alocate some more bytes for the decoded buffer to be
          * sure it will fit.
          */
         length = DEFAULT_PASSPHRASE_LENGTH + 12;
         wrapped_passphrase = (char *)malloc(length);
         memset(wrapped_passphrase, 0, length);
         if (base64_to_bin(wrapped_passphrase, length,
                           keydata, strlen(keydata)) == 0) {
            fprintf(stderr,
                    _("Failed to base64 decode the keydata read from %s, aborting...\n"),
                    keyfile);
            free(wrapped_passphrase);
            goto bail_out;
         }

         length = DEFAULT_PASSPHRASE_LENGTH;
         passphrase = (char *)malloc(length);
         memset(passphrase, 0, length);

         if (aes_unwrap((unsigned char *)wrapdata,
                        length / 8,
                        (unsigned char *)wrapped_passphrase,
                        (unsigned char *)passphrase) == -1) {
            fprintf(stderr,
                    _("Failed to aes unwrap the keydata read from %s using the wrap data from %s, aborting...\n"),
                    keyfile, wrap_keyfile);
            free(wrapped_passphrase);
            goto bail_out;
         }

         free(wrapped_passphrase);
      } else {
         if (base64_transform) {
            /*
             * As we first go from base64 to bin and the base64_to_bin has a check
             * if the decoded string will fit we need to alocate some more bytes
             * for the decoded buffer to be sure it will fit.
             */
            length = DEFAULT_PASSPHRASE_LENGTH + 4;
            passphrase = (char *)malloc(length);
            memset(passphrase, 0, length);

            base64_to_bin(passphrase, length, keydata, strlen(keydata));
         } else {
            length = DEFAULT_PASSPHRASE_LENGTH;
            passphrase = (char *)malloc(length);
            memset(passphrase, 0, length);
            bstrncpy(passphrase, keydata, length);
         }
      }

      Dmsg1(10, "Unwrapped passphrase = %s\n", passphrase);
      fprintf(stdout, "%s\n", passphrase);

      free(passphrase);
      goto bail_out;
   }

   /*
    * Clear the loaded encryption key of the given drive.
    */
   if (clear_encryption) {
      if (clear_scsi_encryption_key(-1, argv[0])) {
         goto bail_out;
      } else {
         retval = 1;
         goto bail_out;
      }
   }

   /*
    * Get the drive encryption status of the given drive.
    */
   if (drive_encryption_status) {
      POOLMEM *encryption_status = get_pool_memory(PM_MESSAGE);

      if (get_scsi_drive_encryption_status(-1, argv[0], encryption_status, 0)) {
         fprintf(stdout, "%s", encryption_status);
         free_pool_memory(encryption_status);
      } else {
         retval = 1;
         free_pool_memory(encryption_status);
         goto bail_out;
      }
   }

   /*
    * Load a new encryption key onto the given drive.
    */
   if (set_encryption) {
      /*
       * Read the key bits from the keyfile.
       * - == stdin
       */
      if (bstrcmp(keyfile, "-")) {
         kfd = 0;
         fprintf(stdout, _("Enter Encryption Key (close with ^D): "));
         fflush(stdout);
      } else {
         kfd = open(keyfile, O_RDONLY);
         if (kfd < 0) {
            fprintf(stderr, _("Cannot open keyfile %s\n"), keyfile);
            retval = 1;
            goto bail_out;
         }
      }
      read(kfd, keydata, sizeof(keydata));
      if (kfd > 0) {
         close(kfd);
      }
      strip_trailing_junk(keydata);

      if (set_scsi_encryption_key(-1, argv[0], keydata)) {
         goto bail_out;
      } else {
         retval = 1;
         goto bail_out;
      }
   }

   /*
    * Get the volume encryption status of volume currently loaded in the given drive.
    */
   if (volume_encryption_status) {
      POOLMEM *encryption_status = get_pool_memory(PM_MESSAGE);

      if (get_scsi_volume_encryption_status(-1, argv[0], encryption_status, 0)) {
         fprintf(stdout, "%s", encryption_status);
         free_pool_memory(encryption_status);
      } else {
         retval = 1;
         free_pool_memory(encryption_status);
         goto bail_out;
      }
   }

bail_out:
   if (cache_file) {
      free(cache_file);
   }

   if (keyfile) {
      free(keyfile);
   }

   if (wrap_keyfile) {
      free(wrap_keyfile);
   }

   exit(retval);
}
