Mix/Src/main.c

/* Mixmaster version 3.0  --  (C) 1999 - 2006 Anonymizer Inc. and others.

   Mixmaster may be redistributed and modified under certain conditions.
   This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
   ANY KIND, either express or implied. See the file COPYRIGHT for
   details.

   Command-line based frontend
   $Id$ */


#include "mix3.h"
#include "pgp.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#ifdef POSIX
#include <unistd.h>
#else /* end of POSIX */
#include <io.h>
#endif /* else if not POSIX */
#include <assert.h>

static char *largopt(char *p, char *opt, char *name, int *error);
static void noarg(char *name, char p);
static int check_get_pass(int force, int never_ask_for_passphrase);

/** main *****************************************************************/

/* Returns:
 0 successful operation
 1 command line error
 2 client error condition */

#ifdef WIN32SERVICE
int mix_main(int argc, char *argv[])
#else
int main(int argc, char *argv[])
#endif /* WIN32SERVICE */
{
  int error = 0, deflt = 1, help = 0, readmail = 0, send = -1, sendpool = 0,
  header = 1, maint = 0, keygen = 0, verbose = 0, sign = 0, encrypt = 0,
  redirect_mail = 0, about=0, version=0;
  int daemon = 0, type_list = 0, nodetach = 0;
  int update_stats = 0, update_pingerlist = 0;
  int never_ask_for_passphrase = 0;

#ifdef USE_SOCK
  int pop3 = 0;

#endif /* USE_SOCK */
  char *filename = NULL;
  int i;
  int ret = 0;
  char *p, *q;
  char chain[1024] = "";
  char nym[LINELEN] = "";
  BUFFER *nymopt, *pseudonym, *attachments, *statssrc;
  int numcopies = 0;            /* default value set in mix.cfg */
  BUFFER *msg, *chainlist, *field, *content;
  FILE *f;
  char pingpath[PATHMAX];

  /* Check if parse_yearmonthday works */
  assert(parse_yearmonthday("2003-04-01") == 1049155200);

  mix_init(NULL);

  msg = buf_new();
  chainlist = buf_new();
  nymopt = buf_new();
  pseudonym = buf_new();
  attachments = buf_new();
  field = buf_new();
  content = buf_new();
  statssrc = buf_new();

#ifdef USE_NCURSES
  if (argc == 1) {
    if (isatty(fileno(stdin)))
      menu_main();
    else
      menu_folder(0, NULL);
    goto clientpool;
  }
#endif /* USE_NCURSES */
  if (argc > 1 && strleft(argv[1], "-f")) {
    menu_folder(strlen(argv[1]) > 2 ? argv[1][2] : 0, argc < 3 ? NULL : argv[2]);
    goto clientpool;
  }
  for (i = 1; i < argc; i++) {
    p = argv[i];
    if (p[0] == '-' && p[1] != '\0') {
      if (p[1] == '-') {
        p += 2;
        if (strieq(p, "help"))
          help = 1, deflt = 0;
        else if (streq(p, "version"))
          version = 1, deflt = 0;
        else if (streq(p, "about"))
          about = 1, deflt = 0;
        else if (streq(p, "verbose"))
          verbose = 1;
        else if (streq(p, "type-list"))
          type_list = 1;
        else if (streq(p, "dummy"))
          send = MSG_NULL, deflt = 0;
        else if (streq(p, "remailer"))
          maint = 1, deflt = 0;
        else if (streq(p, "generate-key"))
          keygen = 2, deflt = 0;
        else if (streq(p, "update-keys"))
          keygen = 1, deflt = 0;
        else if (streq(p, "send"))
          sendpool = 1, deflt = 0;
        else if (streq(p, "read-mail"))
          readmail = 1, deflt = 0;
        else if (streq(p, "redirect"))
          redirect_mail = 1, deflt = 0;
        else if (streq(p, "store-mail"))
          readmail = 2, deflt = 0;
#ifdef USE_SOCK
        else if (streq(p, "pop-mail"))
          pop3 = 1, deflt = 0;
#endif /* USE_SOCK */
        else if (streq(p, "daemon"))
          daemon = 1, deflt = 0;
        else if (streq(p, "no-detach"))
          nodetach = 1;
        else if (streq(p, "post"))
          send = MSG_POST;
        else if (streq(p, "mail"))
          send = MSG_MAIL;
        else if (streq(p, "sign"))
          sign = 1;
        else if (streq(p, "encrypt"))
          encrypt = 1;
        else if (streq(p, "no-ask-passphrase"))
          never_ask_for_passphrase = 1;
        else if (streq(p, "update-pinger-list"))
          update_pingerlist = 1;
        else if (streq(p, "update-stats")) {
          buf_clear(statssrc);
          f = mix_openfile(STATSSRC, "r");
          if (f != NULL) {
            buf_read(statssrc, f);
            fclose(f);
          }
          if (statssrc->length > 0) {
            update_stats = 1;
          } else {
            deflt = 0;
            fprintf(stderr, "%s: No current stats source --%s\n", argv[0], p);
          }
        } else if (strleft(p, "update-stats") && p[strlen("update-stats")] == '=') {
          buf_clear(statssrc);
          buf_appendf(statssrc, "%s", (p + strlen("update-stats") + 1));
          if (statssrc->length > 0) {
            update_stats = 1;
          } else {
            fprintf(stderr, "%s: No stats source specified --%s\n", argv[0], p);
          }
        } else if ((q = largopt(p, "to", argv[0], &error)) != NULL) {
          header = 0;
          buf_appendf(msg, "To: %s\n", q);
        } else if ((q = largopt(p, "post-to", argv[0], &error)) != NULL) {
          send = MSG_POST, header = 0;
          buf_appendf(msg, "Newsgroups: %s\n", q);
        } else if ((q = largopt(p, "subject", argv[0], &error)) != NULL) {
          buf_appendf(msg, "Subject: %s\n", q);
        } else if ((q = largopt(p, "header", argv[0], &error)) != NULL) {
          buf_appendf(msg, "%s\n", q);
        } else if ((q = largopt(p, "chain", argv[0], &error)) != NULL) {
          buf_appendf(msg, "Chain: %s\n", q);
        }
#ifdef USE_PGP
        else if ((q = largopt(p, "reply-chain", argv[0], &error)) != NULL) {
          buf_appendf(msg, "Reply-Chain: %s\n", q);
        } else if ((q = largopt(p, "latency", argv[0], &error)) != NULL) {
          buf_appendf(msg, "Latency: %s\n", q);
        } else if ((q = largopt(p, "attachment", argv[0], &error)) != NULL) {
          buf_appendf(attachments, "%s\n", q);
#ifdef NYMSUPPORT
        } else if ((q = largopt(p, "nym-config", argv[0], &error)) != NULL) {
          deflt = 0;
          strncpy(nym, q, sizeof(nym));
          if (i > argc && strileft(argv[i + 1], "name="))
            buf_sets(pseudonym, argv[++i] + 5);
          else if (i > argc && strileft(argv[i + 1], "opt="))
            buf_appends(nymopt, argv[++i] + 5);
        } else if ((q = largopt(p, "nym", argv[0], &error)) != NULL) {
          buf_appendf(msg, "Nym: %s\n", q);
#endif /* NYMSUPPORT */
        }
#endif /* USE_PGP */
        else if ((q = largopt(p, "copies", argv[0], &error)) != NULL) {
          sscanf(q, "%d", &numcopies);
        } else if ((q = largopt(p, "config", argv[0], &error)) != NULL) {
          strncpy(MIXCONF, q, PATHMAX);
          MIXCONF[PATHMAX-1] = 0;
          mix_config(); /* configuration file changed - reread it */
        } else if (error == 0 && mix_configline(p) == 0) {
          fprintf(stderr, "%s: Invalid option %s\n", argv[0], argv[i]);
          error = 1;
        }
      } else {
        while (*++p) {
          switch (*p) {
          case 'd':
            send = MSG_NULL, deflt = 0;
            break;
          case 'R':
            readmail = 1, deflt = 0;
            break;
          case 'I':
            readmail = 2, deflt = 0;
            break;
          case 'S':
            sendpool = 1, deflt = 0;
            break;
          case 'M':
            maint = 1, deflt = 0;
            break;
#ifdef USE_SOCK
          case 'P':
            pop3 = 1, deflt = 0;
            break;
#endif /* USE_SOCK */
          case 'D':
            daemon = 1, deflt = 0;
            break;
          case 'G':
            keygen = 2, deflt = 0;
            break;
          case 'K':
            keygen = 1, deflt = 0;
            break;
          case 'L':             /* backwards compatibility */
            break;
          case 'v':
            verbose = 1;
            break;
          case 'h':
            help = 1, deflt = 0;
            break;
          case 'T':
            type_list = 1;
            break;
          case 'V':
            version = 1, deflt = 0;
            break;
          case 't':
            if (*(p + 1) == 'o')
              p++;
            header = 0;
            if (i < argc - 1)
              buf_appendf(msg, "To: %s\n", argv[++i]);
            else {
              fprintf(stderr, "%s: Missing argument for option -to\n", argv[0]);
              error = 1;
            }
            break;
          case 's':
            if (i < argc - 1)
              buf_appendf(msg, "Subject: %s\n", argv[++i]);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
          case 'l':
            if (i < argc - 1)
              buf_appendf(msg, "Chain: %s\n", argv[++i]);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
          case 'r':
            if (i < argc - 1)
              buf_appendf(msg, "Reply-Chain: %s\n", argv[++i]);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
#ifdef USE_PGP
          case 'n':
            if (i < argc - 1)
              buf_appendf(msg, "Nym: %s\n", argv[++i]);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
#endif /* USE_PGP */
          case 'c':
            if (i < argc - 1)
              sscanf(argv[++i], "%d", &numcopies);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
          case 'p':
            send = MSG_POST;
            break;
          case 'g':
            if (i < argc - 1) {
              send = MSG_POST, header = 0;
              buf_appendf(msg, "Newsgroups: %s\n", argv[++i]);
            } else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
          case 'a':
            if (i < argc - 1)
              buf_appendf(attachments, "%s\n", argv[++i]);
            else {
              noarg(argv[0], *p);
              error = 1;
            }
            break;
          case 'm':
            send = MSG_MAIL;
            break;
          default:
            fprintf(stderr, "%s: Invalid option -%c\n", argv[0], *p);
            error = 1;
            break;
          }
        }
      }
    } else {
      if (strchr(argv[i], '@')) {
        header = 0;
        buf_appendf(msg, "To: %s\n", argv[i]);
      } else {
        if (filename == NULL)
          filename = argv[i];
        else {
          fprintf(stderr, "%s: Error in command line: %s\n", argv[0], argv[i]);
          error = 1;
        }
      }
    }
  }

  if (error) {
    ret = 1;
    goto end;
  }

  if (type_list) {
    BUFFER *type2list;
    type2list = buf_new();
    if (prepare_type2list(type2list) < 0) {
      fprintf(stderr, "Cannot print type2.list.\n");
      ret = 2;
    } else {
      printf("%s", type2list->data);
    };
    buf_free(type2list);
    goto end;
  }

  if (version) {
    printf("Mixmaster %s\n", VERSION);
    ret = 0;
    goto end;
  }

  if (update_pingerlist) {
    mixfile(pingpath, ALLPINGERSFILE);
    if (verbose) printf ("downloading %s...\n", ALLPINGERSURL);
    if (url_download(ALLPINGERSURL, pingpath) < 0) {
      printf("    Download failed... Try again later.\n");
      errlog(ERRORMSG, "All Pingers File Download failed.\n");
    } else {
      if (verbose) printf("    Done.\n");
      errlog(LOG, "All Pingers File Downloaded OK.\n");
    }
    ret = 0;
    goto end;
  }
  
  if (update_stats) {
    ret = download_stats(statssrc->data);
    if (ret == -3) {
      fprintf(stderr, "Stats source does not include all required files.\n");
    } else if (ret == -2) {
      fprintf(stderr, "Could not open stats source file for writing\n");
    } else if (ret == -1) {
      fprintf(stderr, "Stats source download failed.\n");
    }
    ret = 0;
    goto end;
  }

#ifdef USE_NCURSES
/* If we get here then it's possible we still want to use the NCURSES interface */
    if (deflt && (send == -1) && isatty(fileno(stdin))) {
      menu_main();
      goto clientpool;
    }
#endif /* USE_NCURSES */
  
  if (help ||about ||(isatty(fileno(stdin)) && isatty(fileno(stdout))))
    fprintf(stderr, "Mixmaster %s\n", VERSION);
  if (help ||about)
    printf("\n\n");
  if (about) {
    printf("Many people have contributed to the source code for Mixmaster.\n");
    printf("These contributors include:\n\n");
    printf("Lance Cottrell\n");
    printf("Janis Jagars\n");
    printf("Ulf Moeller\n");
    printf("Peter Palfrader\n");
    printf("Len Sassaman\n");
    printf("\nand others. For full information on copyright and license issues,\n");
    printf("read the bundled file COPYRIGHT.\n\n");
    ret = 0;
    goto end;
  }
  
  if (help) {
    printf("Usage: %s [options] [user@host] [filename]\n\n", argv[0]);
    printf("Options:\n\
\n\
-h, --help                        summary of command line options\n\
-V, --version                     print version information\n\
    --about                       print authorship information\n\
    --config=file                 use alternate configuration file\n\
-T, --type-list                   list available remailers\n\
-t, --to=user@host                the recipient's address(es)\n\
-g, --post-to=newsgroup           newsgroup(s) to post to\n\
-p, --post                        input is a Usenet article\n\
-m, --mail                        input is a mail message\n\
-s, --subject=subject             message subject\n\
    --header='header line'        arbitrary message headers\n\
-a, --attachment=file             attach a file\n"
#ifdef USE_PGP
#ifdef NYMSUPPORT
           "-n, --nym=yournym                 use pseudonym to send the message\n"
#endif /* NYMSUPPORT */
"    --encrypt                     encrypt the message using the PGP format\n\
    --sign                        sign the message using the PGP format\n"
#endif /* USE_PGP */
           "-l, --chain=mix1,mix2,mix3,...    specify a remailer chain\n\
-c, --copies=num                  send num copies to increase reliability\n\
-d, --dummy                       generate a dummy message\n\
-S, --send                        send the message(s) in the pool\n"
#ifdef USE_PGP
#ifdef NYMSUPPORT
           "    --nym-config=yournym          generate a new pseudonym\n\
    --latency=hours               reply chain latency\n\
    --reply-chain=rem1,rem2,...   reply chain for the pseudonym\n"
#endif /* NYMSUPPORT */
#endif /* USE_PGP */
           "-v, --verbose                     output informational messages\n\
-f [file]                         read a mail folder\n\
    --update-pinger-list          Download an updated all pingers list file\n\
    --update-stats[=source]       Download updated stats\n"

#ifndef USE_NCURSES
           "\n-fr, -ff, -fg [file]              send reply/followup/group reply to a message\n"
#endif /* USE_NCURSES */
           "\nThe input file is expected to contain mail headers if no address is\n\
specified in the command line.\n\
\n\
Remailer:\n\
\n\
-R, --read-mail                   read remailer message from stdin\n\
-I, --store-mail                  read remailer msg from stdin, do not decrypt\n\
-M, --remailer                    process the remailer pool\n\
-D, --daemon                      remailer as background process\n\
    --no-detach                   do not detach from terminal as daemon\n"
#ifdef USE_SOCK
           "-S, --send                        force sending messages from the pool\n"
#endif /* USE_SOCK */
           "-P, --pop-mail                    force getting messages from POP3 servers\n\
-G, --generate-key                generate a new remailer key\n\
-K, --update-keys                 generate remailer keys if necessary\n"
#ifdef WIN32SERVICE
           "\n\
WinNT service:\n\
\n\
    --install-svc                 install the service\n\
    --remove-svc                  remove the service\n\
    --run-svc                     run as a service\n"
#endif /* WIN32SERVICE */
    );

    ret = 0;
    goto end;
  }

  if (deflt && send == -1)
    send = MSG_MAIL;
  if (nym[0] != 0)
    send = -1;
  if ((send == MSG_MAIL || send == MSG_POST) && filename == NULL &&
      header == 1 && isatty(fileno(stdin))) {
    /* we don't get here if USE_NCURSES is set */
    printf("Run `%s -h' to view a summary of the command line options.\n\nEnter the message, complete with headers.\n",
           argv[0]);
#ifdef UNIX
    printf("When done, press ^D.\n\n");
#else
    printf("When done, press ^Z.\n\n");
#endif /* else not UNIX */
  }
  if (header == 0)
    buf_nl(msg);

  /* timeskew check */
  if (REMAIL == 1)
    mix_check_timeskew();

  if (readmail || redirect_mail || send == MSG_MAIL || send == MSG_POST) {
    if (filename == NULL || streq(filename, "-"))
      f = stdin;
    else {
      f = fopen(filename, "r");
      if (f == NULL)
        fprintf(stderr, "Can't open %s.\n", filename);
    }

    if (f && buf_read(msg, f) != -1) {
      if (readmail == 1) {
        check_get_pass(1, never_ask_for_passphrase);
        mix_decrypt(msg);
      } else if (readmail == 2)
        pool_add(msg, "inf");
      if (send == MSG_MAIL || send == MSG_POST || redirect_mail) {
        BUFFER *sendmsg;
        int numdest = 0;

        sendmsg = buf_new();

        while (buf_getheader(msg, field, content) == 0) {
          if (bufieq(field, "nym")) {
            strncpy(nym, content->data, sizeof(nym));
          } else if (bufieq(field, "chain"))
            if (strchr(content->data, ';')) {
              i = strchr(content->data, ';') - (char *)content->data;
              strncpy(chain, content->data, i);
              if (strstr(content->data + i, "copies=") != NULL) {
                sscanf(strstr(content->data + i, "copies=") +
                       sizeof("copies=") - 1, "%d", &numcopies);
              }
            } else
              strncpy(chain, content->data, sizeof(chain));
          else {                /* line goes into message */
            if (((redirect_mail || send == MSG_MAIL) && bufieq(field, "to"))
                || (send == MSG_POST && bufieq(field, "newsgroups")))
              numdest++;
            if (bufieq(field, "from") && !redirect_mail)
              fprintf(stderr, "Warning: The message has a From: line.\n");
            buf_appendheader(sendmsg, field, content);
          }
        }
        buf_nl(sendmsg);
        buf_rest(sendmsg, msg);

        while (buf_getline(attachments, field) != -1)
          if (attachfile(sendmsg, field) == -1) {
            errlog(ERRORMSG, "Can't attach %b!\n", field);
            ret = 2;
            goto end;
          }

#ifdef USE_PGP
        if (nym[0] != 0 && strchr(nym, '@') == NULL)
          strcatn(nym, "@", sizeof(nym));
        if (sign || encrypt) {
          BUFFER *pass;

          pass = buf_new();
          user_pass(pass);
          if (pgp_mailenc((encrypt ? PGP_ENCRYPT : 0) |
                          (nym[0] != 0 && sign ? PGP_SIGN : 0) |
                          PGP_TEXT | PGP_REMAIL, sendmsg, nym,
                          pass, NULL, NYMSECRING) != 0) {
            fprintf(stderr, "Encryption failed: missing key!");
            ret = 2;
            goto end;
          }
          buf_free(pass);
        }
        if (nym[0] != 0) {
#ifdef NYMSUPPORT
          if (nym_encrypt(sendmsg, nym, send) == 0)
            send = MSG_MAIL;
          else
#endif /* NYMSUPPORT */
            fprintf(stderr, "Nym error, sending message anonymously.\n");
        }
#endif /* USE_PGP */
        if (numdest == 0) {
          fprintf(stderr, "No destination address given!\n");
          ret = 2;
        } else if (numcopies < 0 || numcopies > 10) {
          fprintf(stderr, "Invalid number of copies!\n");
          ret = 2;
        } else {
          if ( ( redirect_mail ?
                redirect_message(sendmsg, chain, numcopies, chainlist) :
                mix_encrypt(send, sendmsg, chain, numcopies, chainlist)
                ) == -1) {
            ret = 2;
            if (chainlist->length)
              fprintf(stderr, "%s\n", chainlist->data);
            else
              fprintf(stderr, "Failed!\n");
          } else if (verbose) {
            fprintf(stderr, "Chain: ");
            buf_write(chainlist, stderr);
          }
        }

        buf_free(sendmsg);
      }
      if (filename != NULL)
        fclose(f);
    } else
      ret = 2;
  }
  if (send == MSG_NULL) {
    if (msg->length) {
      while (buf_getheader(msg, field, content) == 0) {
        if (bufieq(field, "chain"))
          strncpy(chain, content->data, sizeof(chain));
      }
    }
    if (mix_encrypt(MSG_NULL, NULL, chain, numcopies, chainlist) == -1) {
      ret = 2;
      if (chainlist->length)
        printf("%s\n", chainlist->data);
      else
        fprintf(stderr, "Failed!\n");
    } else if (verbose) {
      printf("Chain: ");
      buf_write(chainlist, stdout);
    }
  }
#ifdef USE_PGP
#ifdef NYMSUPPORT
  if (nym[0] != 0) {
    char nymserver[LINELEN] = "*";
    BUFFER *chains;

    chains = buf_new();
    if (numcopies < 1 || numcopies > 10)
      numcopies = 1;
    while (buf_getheader(msg, field, content) != -1) {
      if (bufieq(field, "chain"))
        strncpy(chain, content->data, sizeof(chain));
      else if (bufieq(field, "reply-chain"))
        buf_appendf(chains, "Chain: %b\n", content);
      else if (field->length)
        buf_appendheader(chains, field, content);
      else
        buf_nl(chains);
    }
    if (strrchr(nym, '@')) {
      strncpy(nymserver, strrchr(nym, '@'), sizeof(nymserver));
      *strrchr(nym, '@') = '\0';
    }
    if (nym_config(NYM_CREATE, nym, nymserver, pseudonym,
                   chain, numcopies, chains, nymopt) < 0) {
      ret = 2;
      fprintf(stderr, "Failed!\n");
    }
    user_delpass();
    buf_free(chains);
  }
#endif /* NYMSUPPORT */
#endif /* USE_PGP */

  if (keygen) {
    check_get_pass(0, never_ask_for_passphrase);
    keymgt(keygen);
  }
  if (sendpool)
    mix_send();
#ifdef USE_SOCK
  if (pop3)
    pop3get();
#endif /* USE_SOCK */
  if (maint) {
    check_get_pass(1, never_ask_for_passphrase);
    mix_regular(0);
  }

clientpool:
  if ((REMAIL == 0) && (CLIENTAUTOFLUSH == 1)) {
    SENDPOOLTIME = 0;
    RATE = 100;
    mix_send();
  };

end:
  buf_free(field);
  buf_free(content);
  buf_free(chainlist);
  buf_free(msg);
  buf_free(nymopt);
  buf_free(pseudonym);
  buf_free(attachments);
  buf_free(statssrc);

  if (daemon) {
    check_get_pass(1, never_ask_for_passphrase);
#ifdef UNIX
    if (! nodetach) {
      int pid;

      fprintf(stderr, "Detaching.\n");
      /* Detach as suggested by the Unix Programming FAQ */
      pid = fork();
      if (pid > 0)
        exit(0);
      if (setsid() < 0) {
        /* This should never happen. */
        fprintf(stderr, "setsid() failed.\n");
        exit(1);
      };
      pid = fork();
      if (pid > 0)
        exit(0);
    };
    if (chdir(MIXDIR) < 0) {
      if (chdir("/") < 0) {
        fprintf(stderr, "Cannot chdir to mixdir or /.\n");
        exit(1);
      };
    };
    if (write_pidfile(PIDFILE)) {
      fprintf(stderr, "Aborting.\n");
      exit(1);
    }
    if (! nodetach) {
      freopen ("/dev/null", "r", stdin);
      freopen ("/dev/null", "w", stdout);
      freopen ("/dev/null", "w", stderr);
    }
#endif /* UNIX */
    mix_daemon();
#ifdef UNIX
/* ifdef this one too, so that we do not need to export it from windows dll */
    clear_pidfile(PIDFILE);
#endif /* UNIX */
  }
  mix_exit();
  return (ret);
}

static char *largopt(char *p, char *opt, char *name, int *error)
{
  if (streq(p, opt)) {
    fprintf(stderr, "%s: Missing argument for option --%s\n", name, p);
    *error = 1;
  } else if (strleft(p, opt) && p[strlen(opt)] == '=') {
    return (p + strlen(opt) + 1);
  }
  return (NULL);
}

static void noarg(char *name, char p)
{
  fprintf(stderr, "%s: Missing argument for option -%c\n", name, p);
}

static int check_get_pass(int force, int never_ask_for_passphrase)
/* get a passphrase and check against keys
 * if force != 0 passphrase must match with some key */
{
    BUFFER *pass, *pass2, *key;
    int n = 0;

    if (PASSPHRASE[0] == '\0' && isatty(fileno(stdin)) && ! never_ask_for_passphrase) {
      pass = buf_new();
      pass2 = buf_new();
      key = buf_new();
      buf_sets(pass, PASSPHRASE);
      while (
#ifdef USE_PGP
             pgpdb_getkey(PK_DECRYPT, PGP_ES_RSA, NULL, NULL, NULL, NULL, NULL,
                           NULL, NULL, NULL, pass) < 0 &&
             pgpdb_getkey(PK_DECRYPT, PGP_E_ELG,  NULL, NULL, NULL, NULL, NULL,
                           NULL, NULL, NULL, pass) < 0 &&
#endif /* USE_PGP */
             getv2seckey(NULL, key) < 0)
      {
        user_delpass();
        if (n)
          fprintf(stderr, "re-");
        user_pass(pass);
        strncpy(PASSPHRASE, pass->data, LINELEN);
        PASSPHRASE[LINELEN-1] = 0;
        if (!force) {
          if (n && buf_eq(pass, pass2))
            break;
          buf_set(pass2, pass);
        }
        n=1;
      }
      user_delpass();
      buf_free(pass);
      buf_free(pass2);
      buf_free(key);

      strncpy(ENTEREDPASSPHRASE, PASSPHRASE, LINELEN);
      ENTEREDPASSPHRASE[LINELEN-1] = 0;
    }
    return 1;
}