g10/plaintext.c

   1 /* plaintext.c -  process plaintext packets
   2  * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   3  *               2006 Free Software Foundation, Inc.
   4  *
   5  * This file is part of GnuPG.
   6  *
   7  * GnuPG is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * GnuPG is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <assert.h>
  27 #include <sys/types.h>
  28 #ifdef HAVE_DOSISH_SYSTEM
  29 #include <fcntl.h> /* for setmode() */
  30 #endif
  31
  32 #include "gpg.h"
  33 #include "util.h"
  34 #include "options.h"
  35 #include "packet.h"
  36 #include "ttyio.h"
  37 #include "filter.h"
  38 #include "main.h"
  39 #include "status.h"
  40 #include "i18n.h"
  41
  42
  43 /****************
  44  * Handle a plaintext packet.  If MFX is not NULL, update the MDs
  45  * Note: we should use the filter stuff here, but we have to add some
  46  *       easy mimic to set a read limit, so we calculate only the
  47  *       bytes from the plaintext.
  48  */
  49 int
  50 handle_plaintext( PKT_plaintext *pt, md_filter_context_t *mfx,
  51                   int nooutput, int clearsig )
  52 {
  53     char *fname = NULL;
  54     FILE *fp = NULL;
  55     static off_t count=0;
  56     int rc = 0;
  57     int c;
  58     int convert = (pt->mode == 't' || pt->mode == 'u');
  59 #ifdef __riscos__
  60     int filetype = 0xfff;
  61 #endif
  62
  63     /* Let people know what the plaintext info is. This allows the
  64        receiving program to try and do something different based on
  65        the format code (say, recode UTF-8 to local). */
  66     if(!nooutput && is_status_enabled())
  67       {
  68         char status[50];
  69
  70         /* Better make sure that stdout has been flushed in case the
  71            output will be written to it.  This is to make sure that no
  72            not-yet-flushed stuff will be written after the plaintext
  73            status message.  */
  74         fflush (stdout);
  75
  76         sprintf(status,"%X %lu ",(byte)pt->mode,(ulong)pt->timestamp);
  77         write_status_text_and_buffer(STATUS_PLAINTEXT,
  78                                      status,pt->name,pt->namelen,0);
  79
  80         if(!pt->is_partial)
  81           {
  82             sprintf(status,"%lu",(ulong)pt->len);
  83             write_status_text(STATUS_PLAINTEXT_LENGTH,status);
  84           }
  85       }
  86
  87     /* create the filename as C string */
  88     if( nooutput )
  89         ;
  90     else if( opt.outfile ) {
  91         fname = xmalloc( strlen( opt.outfile ) + 1);
  92         strcpy(fname, opt.outfile );
  93     }
  94     else if( pt->namelen == 8 && !memcmp( pt->name, "_CONSOLE", 8 ) ) {
  95         log_info(_("data not saved; use option \"--output\" to save it\n"));
  96         nooutput = 1;
  97     }
  98     else if( !opt.flags.use_embedded_filename ) {
  99         fname = make_outfile_name( iobuf_get_real_fname(pt->buf) );
 100         if( !fname )
 101             fname = ask_outfile_name( pt->name, pt->namelen );
 102         if( !fname ) {
 103              rc = gpg_error (GPG_ERR_GENERAL); /* Can't create file. */
 104              goto leave;
 105         }
 106     }
 107     else
 108       fname=utf8_to_native(pt->name,pt->namelen,0);
 109
 110     if( nooutput )
 111         ;
 112     else if ( iobuf_is_pipe_filename (fname) || !*fname)
 113       {
 114         /* No filename or "-" given; write to stdout. */
 115         fp = stdout;
 116 #ifdef HAVE_DOSISH_SYSTEM
 117         setmode ( fileno(fp) , O_BINARY );
 118 #endif
 119       }
 120     else {
 121         while( !overwrite_filep (fname) ) {
 122             char *tmp = ask_outfile_name (NULL, 0);
 123             if ( !tmp || !*tmp ) {
 124                 xfree (tmp);
 125                 rc = gpg_error (GPG_ERR_GENERAL); /* G10ERR_CREATE_FILE*/
 126                 goto leave;
 127             }
 128             xfree (fname);
 129             fname = tmp;
 130         }
 131     }
 132
 133 #ifndef __riscos__
 134     if( fp || nooutput )
 135         ;
 136     else if (is_secured_filename (fname))
 137       {
 138         errno = EPERM;
 139         rc = gpg_error_from_syserror ();
 140         log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 141         goto leave;
 142       }
 143     else if( !(fp = fopen(fname,"wb")) ) {
 144         rc = gpg_error_from_syserror ();
 145         log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 146         goto leave;
 147     }
 148 #else /* __riscos__ */
 149     /* If no output filename was given, i.e. we constructed it,
 150        convert all '.' in fname to '/' but not vice versa as
 151        we don't create directories! */
 152     if( !opt.outfile )
 153         for( c=0; fname[c]; ++c )
 154             if( fname[c] == '.' )
 155                 fname[c] = '/';
 156
 157     if( fp || nooutput )
 158         ;
 159     else {
 160         fp = fopen(fname,"wb");
 161         if( !fp ) {
 162             log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 163             rc = G10ERR_CREATE_FILE;
 164             if (errno == 106)
 165                 log_info("Do output file and input file have the same name?\n");
 166             goto leave;
 167         }
 168
 169         /* If there's a ,xxx extension in the embedded filename,
 170            use that, else check whether the user input (in fname)
 171            has a ,xxx appended, then use that in preference */
 172         if( (c = riscos_get_filetype_from_string( pt->name,
 173                                                   pt->namelen )) != -1 )
 174             filetype = c;
 175         if( (c = riscos_get_filetype_from_string( fname,
 176                                                   strlen(fname) )) != -1 )
 177             filetype = c;
 178         riscos_set_filetype_by_number(fname, filetype);
 179     }
 180 #endif /* __riscos__ */
 181
 182     if( !pt->is_partial ) {
 183         /* We have an actual length (which might be zero). */
 184
 185         if (clearsig) {
 186             log_error ("clearsig encountered while not expected\n");
 187             rc = G10ERR_UNEXPECTED;
 188             goto leave;
 189         }
 190
 191         if( convert ) { /* text mode */
 192             for( ; pt->len; pt->len-- ) {
 193                 if( (c = iobuf_get(pt->buf)) == -1 ) {
 194                     rc = gpg_error_from_syserror ();
 195                     log_error ("problem reading source (%u bytes remaining)\n",
 196                                (unsigned)pt->len);
 197                     goto leave;
 198                 }
 199                 if( mfx->md )
 200                     gcry_md_putc (mfx->md, c );
 201 #ifndef HAVE_DOSISH_SYSTEM
 202                 if( c == '\r' )  /* convert to native line ending */
 203                     continue;    /* fixme: this hack might be too simple */
 204 #endif
 205                 if( fp )
 206                   {
 207                     if(opt.max_output && (++count)>opt.max_output)
 208                       {
 209                         log_error ("error writing to `%s': %s\n",
 210                                    fname,"exceeded --max-output limit\n");
 211                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 212                         goto leave;
 213                       }
 214                     else if( putc( c, fp ) == EOF )
 215                       {
 216                         if (ferror (fp))
 217                           rc = gpg_error_from_syserror ();
 218                         else
 219                           rc = gpg_error (GPG_ERR_EOF);
 220                         log_error ("error writing to `%s': %s\n",
 221                                    fname, strerror(errno) );
 222                         goto leave;
 223                       }
 224                   }
 225             }
 226         }
 227         else { /* binary mode */
 228             byte *buffer = xmalloc( 32768 );
 229             while( pt->len ) {
 230                 int len = pt->len > 32768 ? 32768 : pt->len;
 231                 len = iobuf_read( pt->buf, buffer, len );
 232                 if( len == -1 ) {
 233                     rc = gpg_error_from_syserror ();
 234                     log_error ("problem reading source (%u bytes remaining)\n",
 235                                (unsigned)pt->len);
 236                     xfree( buffer );
 237                     goto leave;
 238                 }
 239                 if( mfx->md )
 240                     gcry_md_write ( mfx->md, buffer, len );
 241                 if( fp )
 242                   {
 243                     if(opt.max_output && (count+=len)>opt.max_output)
 244                       {
 245                         log_error ("error writing to `%s': %s\n",
 246                                    fname,"exceeded --max-output limit\n");
 247                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 248                         xfree( buffer );
 249                         goto leave;
 250                       }
 251                     else if( fwrite( buffer, 1, len, fp ) != len )
 252                       {
 253                         rc = gpg_error_from_syserror ();
 254                         log_error ("error writing to `%s': %s\n",
 255                                    fname, strerror(errno) );
 256                         xfree( buffer );
 257                         goto leave;
 258                       }
 259                   }
 260                 pt->len -= len;
 261             }
 262             xfree( buffer );
 263         }
 264     }
 265     else if( !clearsig ) {
 266         if( convert ) { /* text mode */
 267             while( (c = iobuf_get(pt->buf)) != -1 ) {
 268                 if( mfx->md )
 269                     gcry_md_putc (mfx->md, c );
 270 #ifndef HAVE_DOSISH_SYSTEM
 271                 if( convert && c == '\r' )
 272                     continue; /* fixme: this hack might be too simple */
 273 #endif
 274                 if( fp )
 275                   {
 276                     if(opt.max_output && (++count)>opt.max_output)
 277                       {
 278                         log_error("Error writing to `%s': %s\n",
 279                                   fname,"exceeded --max-output limit\n");
 280                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 281                         goto leave;
 282                       }
 283                     else if( putc( c, fp ) == EOF )
 284                       {
 285                         if ( ferror (fp ) )
 286                           rc = gpg_error_from_syserror ();
 287                         else
 288                           rc = gpg_error (GPG_ERR_EOF);
 289                         log_error("error writing to `%s': %s\n",
 290                                   fname, strerror(errno) );
 291                         goto leave;
 292                       }
 293                   }
 294             }
 295         }
 296         else { /* binary mode */
 297             byte *buffer = xmalloc( 32768 );
 298             int eof_seen = 0;
 299
 300             while ( !eof_seen ) {
 301                 /* Why do we check for len < 32768:
 302                  * If we won't, we would practically read 2 EOFs but
 303                  * the first one has already popped the block_filter
 304                  * off and therefore we don't catch the boundary.
 305                  * So, always assume EOF if iobuf_read returns less bytes
 306                  * then requested */
 307                 int len = iobuf_read( pt->buf, buffer, 32768 );
 308                 if( len == -1 )
 309                     break;
 310                 if( len < 32768 )
 311                     eof_seen = 1;
 312                 if( mfx->md )
 313                     gcry_md_write ( mfx->md, buffer, len );
 314                 if( fp )
 315                   {
 316                     if(opt.max_output && (count+=len)>opt.max_output)
 317                       {
 318                         log_error("error writing to `%s': %s\n",
 319                                   fname,"exceeded --max-output limit\n");
 320                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 321                         xfree( buffer );
 322                         goto leave;
 323                       }
 324                     else if( fwrite( buffer, 1, len, fp ) != len ) {
 325                       rc = (errno? gpg_error_from_syserror ()
 326                             : gpg_error (GPG_ERR_INTERNAL));
 327                       log_error ("error writing to `%s': %s\n",
 328                                 fname, strerror(errno) );
 329                       xfree( buffer );
 330                       goto leave;
 331                     }
 332                   }
 333             }
 334             xfree( buffer );
 335         }
 336         pt->buf = NULL;
 337     }
 338     else {  /* clear text signature - don't hash the last cr,lf  */
 339         int state = 0;
 340
 341         while( (c = iobuf_get(pt->buf)) != -1 ) {
 342             if( fp )
 343               {
 344                 if(opt.max_output && (++count)>opt.max_output)
 345                   {
 346                     log_error ("error writing to `%s': %s\n",
 347                               fname,"exceeded --max-output limit\n");
 348                     rc = gpg_error (GPG_ERR_TOO_LARGE);
 349                     goto leave;
 350                   }
 351                 else if( putc( c, fp ) == EOF )
 352                   {
 353                     rc = (errno? gpg_error_from_syserror ()
 354                           : gpg_error (GPG_ERR_INTERNAL));
 355                     log_error ("error writing to `%s': %s\n",
 356                               fname, strerror(errno) );
 357                     goto leave;
 358                   }
 359               }
 360             if( !mfx->md )
 361                 continue;
 362             if( state == 2 ) {
 363                 gcry_md_putc (mfx->md, '\r' );
 364                 gcry_md_putc (mfx->md, '\n' );
 365                 state = 0;
 366             }
 367             if( !state ) {
 368                 if( c == '\r'  )
 369                     state = 1;
 370                 else if( c == '\n'  )
 371                     state = 2;
 372                 else
 373                     gcry_md_putc(mfx->md, c );
 374             }
 375             else if( state == 1 ) {
 376                 if( c == '\n'  )
 377                     state = 2;
 378                 else {
 379                     gcry_md_putc(mfx->md, '\r' );
 380                     if( c == '\r'  )
 381                         state = 1;
 382                     else {
 383                         state = 0;
 384                         gcry_md_putc(mfx->md, c );
 385                     }
 386                 }
 387             }
 388         }
 389         pt->buf = NULL;
 390     }
 391
 392     if( fp && fp != stdout && fclose(fp) ) {
 393         rc = (errno? gpg_error_from_syserror ()
 394               : gpg_error (GPG_ERR_INTERNAL));
 395         log_error ("error closing `%s': %s\n", fname, strerror(errno) );
 396         fp = NULL;
 397         goto leave;
 398     }
 399     fp = NULL;
 400
 401   leave:
 402     /* Make sure that stdout gets flushed after the plaintext has
 403        been handled.  This is for extra security as we do a
 404        flush anyway before checking the signature.  */
 405     fflush (stdout);
 406
 407     if( fp && fp != stdout )
 408       fclose (fp);
 409     xfree(fname);
 410     return rc;
 411 }
 412
 413 static void
 414 do_hash( gcry_md_hd_t md, gcry_md_hd_t md2, IOBUF fp, int textmode )
 415 {
 416     text_filter_context_t tfx;
 417     int c;
 418
 419     if( textmode ) {
 420         memset( &tfx, 0, sizeof tfx);
 421         iobuf_push_filter( fp, text_filter, &tfx );
 422     }
 423     if( md2 ) { /* work around a strange behaviour in pgp2 */
 424         /* It seems that at least PGP5 converts a single CR to a CR,LF too */
 425         int lc = -1;
 426         while( (c = iobuf_get(fp)) != -1 ) {
 427             if( c == '\n' && lc == '\r' )
 428                 gcry_md_putc (md2, c);
 429             else if( c == '\n' ) {
 430                 gcry_md_putc (md2, '\r');
 431                 gcry_md_putc (md2, c);
 432             }
 433             else if( c != '\n' && lc == '\r' ) {
 434                 gcry_md_putc (md2, '\n');
 435                 gcry_md_putc (md2, c);
 436             }
 437             else
 438                 gcry_md_putc (md2, c);
 439
 440             if( md )
 441                 gcry_md_putc (md, c );
 442             lc = c;
 443         }
 444     }
 445     else {
 446         while( (c = iobuf_get(fp)) != -1 ) {
 447             if( md )
 448                 gcry_md_putc (md, c );
 449         }
 450     }
 451 }
 452
 453
 454 /****************
 455  * Ask for the detached datafile and calculate the digest from it.
 456  * INFILE is the name of the input file.
 457  */
 458 int
 459 ask_for_detached_datafile (gcry_md_hd_t md, gcry_md_hd_t md2,
 460                            const char *inname, int textmode )
 461 {
 462     progress_filter_context_t *pfx;
 463     char *answer = NULL;
 464     IOBUF fp;
 465     int rc = 0;
 466
 467     pfx = new_progress_context ();
 468     fp = open_sigfile ( inname, pfx ); /* Open default file. */
 469
 470     if( !fp && !opt.batch ) {
 471         int any=0;
 472         tty_printf(_("Detached signature.\n"));
 473         do {
 474             char *name;
 475
 476             xfree(answer);
 477             tty_enable_completion(NULL);
 478             name = cpr_get("detached_signature.filename",
 479                            _("Please enter name of data file: "));
 480             tty_disable_completion();
 481             cpr_kill_prompt();
 482             answer=make_filename(name,(void *)NULL);
 483             xfree(name);
 484
 485             if( any && !*answer ) {
 486                 rc = gpg_error (GPG_ERR_GENERAL); /*G10ERR_READ_FILE*/
 487                 goto leave;
 488             }
 489             fp = iobuf_open(answer);
 490             if (fp && is_secured_file (iobuf_get_fd (fp)))
 491               {
 492                 iobuf_close (fp);
 493                 fp = NULL;
 494                 errno = EPERM;
 495               }
 496             if( !fp && errno == ENOENT ) {
 497                 tty_printf("No such file, try again or hit enter to quit.\n");
 498                 any++;
 499             }
 500             else if( !fp )
 501               {
 502                 rc = gpg_error_from_syserror ();
 503                 log_error(_("can't open `%s': %s\n"), answer, strerror(errno));
 504                 goto leave;
 505               }
 506         } while( !fp );
 507     }
 508
 509     if( !fp ) {
 510         if( opt.verbose )
 511             log_info(_("reading stdin ...\n"));
 512         fp = iobuf_open( NULL );
 513         assert(fp);
 514     }
 515     do_hash( md, md2, fp, textmode );
 516     iobuf_close(fp);
 517
 518   leave:
 519     xfree(answer);
 520     release_progress_context (pfx);
 521     return rc;
 522 }
 523
 524
 525
 526 /****************
 527  * Hash the given files and append the hash to hash context md.
 528  * If FILES is NULL, hash stdin.
 529  */
 530 int
 531 hash_datafiles( gcry_md_hd_t md, gcry_md_hd_t md2, strlist_t files,
 532                 const char *sigfilename, int textmode )
 533 {
 534     progress_filter_context_t *pfx;
 535     IOBUF fp;
 536     strlist_t sl;
 537
 538     pfx = new_progress_context ();
 539
 540     if( !files ) {
 541         /* check whether we can open the signed material */
 542         fp = open_sigfile( sigfilename, pfx );
 543         if( fp ) {
 544             do_hash( md, md2, fp, textmode );
 545             iobuf_close(fp);
 546             release_progress_context (pfx);
 547             return 0;
 548         }
 549         log_error (_("no signed data\n"));
 550         release_progress_context (pfx);
 551         return gpg_error (GPG_ERR_NO_DATA);
 552     }
 553
 554
 555     for (sl=files; sl; sl = sl->next ) {
 556         fp = iobuf_open( sl->d );
 557         if (fp && is_secured_file (iobuf_get_fd (fp)))
 558           {
 559             iobuf_close (fp);
 560             fp = NULL;
 561             errno = EPERM;
 562           }
 563         if( !fp ) {
 564             int rc = gpg_error_from_syserror ();
 565             log_error(_("can't open signed data `%s'\n"),
 566                                                 print_fname_stdin(sl->d));
 567             release_progress_context (pfx);
 568             return rc;
 569         }
 570         handle_progress (pfx, fp, sl->d);
 571         do_hash( md, md2, fp, textmode );
 572         iobuf_close(fp);
 573     }
 574
 575     release_progress_context (pfx);
 576     return 0;
 577 }
 578
 579
 580 /* Hash the data from file descriptor DATA_FD and append the hash to hash
 581    contexts MD and MD2.  */
 582 int
 583 hash_datafile_by_fd ( gcry_md_hd_t md, gcry_md_hd_t md2, int data_fd,
 584                       int textmode )
 585 {
 586   progress_filter_context_t *pfx = new_progress_context ();
 587   iobuf_t fp;
 588
 589   fp = iobuf_fdopen (data_fd, "rb");
 590   if (fp && is_secured_file (data_fd))
 591     {
 592       iobuf_close (fp);
 593       fp = NULL;
 594       errno = EPERM;
 595     }
 596   if ( !fp )
 597     {
 598       int rc = gpg_error_from_syserror ();
 599       log_error ( _("can't open signed data fd=%d: %s\n"),
 600                   data_fd, strerror (errno));
 601       release_progress_context (pfx);
 602       return rc;
 603     }
 604
 605   handle_progress (pfx, fp, NULL);
 606
 607   do_hash ( md, md2, fp, textmode);
 608
 609   iobuf_close(fp);
 610
 611   release_progress_context (pfx);
 612   return 0;
 613 }
 614
 615
 616 /* Set up a plaintext packet with the appropriate filename.  If there
 617    is a --set-filename, use it (it's already UTF8).  If there is a
 618    regular filename, UTF8-ize it if necessary.  If there is no
 619    filenames at all, set the field empty. */
 620
 621 PKT_plaintext *
 622 setup_plaintext_name(const char *filename,IOBUF iobuf)
 623 {
 624   PKT_plaintext *pt;
 625
 626   if(filename || opt.set_filename)
 627     {
 628       char *s;
 629
 630       if(opt.set_filename)
 631         s=make_basename(opt.set_filename,iobuf_get_real_fname(iobuf));
 632       else if(filename && !opt.flags.utf8_filename)
 633         {
 634           char *tmp=native_to_utf8(filename);
 635           s=make_basename(tmp,iobuf_get_real_fname(iobuf));
 636           xfree(tmp);
 637         }
 638       else
 639         s=make_basename(filename,iobuf_get_real_fname(iobuf));
 640
 641       pt = xmalloc (sizeof *pt + strlen(s) - 1);
 642       pt->namelen = strlen (s);
 643       memcpy (pt->name, s, pt->namelen);
 644       xfree (s);
 645     }
 646   else
 647     {
 648       /* no filename */
 649       pt = xmalloc (sizeof *pt - 1);
 650       pt->namelen = 0;
 651     }
 652
 653   return pt;
 654 }