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 2 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, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  20  * USA.
  21  */
  22
  23 #include <config.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <assert.h>
  29 #include <sys/types.h>
  30 #ifdef HAVE_DOSISH_SYSTEM
  31 #include <fcntl.h> /* for setmode() */
  32 #endif
  33
  34 #include "gpg.h"
  35 #include "util.h"
  36 #include "options.h"
  37 #include "packet.h"
  38 #include "ttyio.h"
  39 #include "filter.h"
  40 #include "main.h"
  41 #include "status.h"
  42 #include "i18n.h"
  43
  44
  45 /****************
  46  * Handle a plaintext packet.  If MFX is not NULL, update the MDs
  47  * Note: we should use the filter stuff here, but we have to add some
  48  *       easy mimic to set a read limit, so we calculate only the
  49  *       bytes from the plaintext.
  50  */
  51 int
  52 handle_plaintext( PKT_plaintext *pt, md_filter_context_t *mfx,
  53                   int nooutput, int clearsig )
  54 {
  55     char *fname = NULL;
  56     FILE *fp = NULL;
  57     static off_t count=0;
  58     int rc = 0;
  59     int c;
  60     int convert = (pt->mode == 't' || pt->mode == 'u');
  61 #ifdef __riscos__
  62     int filetype = 0xfff;
  63 #endif
  64
  65     /* Let people know what the plaintext info is. This allows the
  66        receiving program to try and do something different based on
  67        the format code (say, recode UTF-8 to local). */
  68     if(!nooutput && is_status_enabled())
  69       {
  70         char status[50];
  71
  72         sprintf(status,"%X %lu ",(byte)pt->mode,(ulong)pt->timestamp);
  73         write_status_text_and_buffer(STATUS_PLAINTEXT,
  74                                      status,pt->name,pt->namelen,0);
  75
  76         if(!pt->is_partial)
  77           {
  78             sprintf(status,"%lu",(ulong)pt->len);
  79             write_status_text(STATUS_PLAINTEXT_LENGTH,status);
  80           }
  81       }
  82
  83     /* create the filename as C string */
  84     if( nooutput )
  85         ;
  86     else if( opt.outfile ) {
  87         fname = xmalloc( strlen( opt.outfile ) + 1);
  88         strcpy(fname, opt.outfile );
  89     }
  90     else if( pt->namelen == 8 && !memcmp( pt->name, "_CONSOLE", 8 ) ) {
  91         log_info(_("data not saved; use option \"--output\" to save it\n"));
  92         nooutput = 1;
  93     }
  94     else if( !opt.flags.use_embedded_filename ) {
  95         fname = make_outfile_name( iobuf_get_real_fname(pt->buf) );
  96         if( !fname )
  97             fname = ask_outfile_name( pt->name, pt->namelen );
  98         if( !fname ) {
  99              rc = gpg_error (GPG_ERR_GENERAL); /* Can't create file. */
 100              goto leave;
 101         }
 102     }
 103     else
 104       fname=utf8_to_native(pt->name,pt->namelen,0);
 105
 106     if( nooutput )
 107         ;
 108     else if ( iobuf_is_pipe_filename (fname) || !*fname)
 109       {
 110         /* No filename or "-" given; write to stdout. */
 111         fp = stdout;
 112 #ifdef HAVE_DOSISH_SYSTEM
 113         setmode ( fileno(fp) , O_BINARY );
 114 #endif
 115       }
 116     else {
 117         while( !overwrite_filep (fname) ) {
 118             char *tmp = ask_outfile_name (NULL, 0);
 119             if ( !tmp || !*tmp ) {
 120                 xfree (tmp);
 121                 rc = gpg_error (GPG_ERR_GENERAL); /* G10ERR_CREATE_FILE*/
 122                 goto leave;
 123             }
 124             xfree (fname);
 125             fname = tmp;
 126         }
 127     }
 128
 129 #ifndef __riscos__
 130     if( fp || nooutput )
 131         ;
 132     else if (is_secured_filename (fname))
 133       {
 134         errno = EPERM;
 135         rc = gpg_error_from_syserror ();
 136         log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 137         goto leave;
 138       }
 139     else if( !(fp = fopen(fname,"wb")) ) {
 140         rc = gpg_error_from_syserror ();
 141         log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 142         goto leave;
 143     }
 144 #else /* __riscos__ */
 145     /* If no output filename was given, i.e. we constructed it,
 146        convert all '.' in fname to '/' but not vice versa as
 147        we don't create directories! */
 148     if( !opt.outfile )
 149         for( c=0; fname[c]; ++c )
 150             if( fname[c] == '.' )
 151                 fname[c] = '/';
 152
 153     if( fp || nooutput )
 154         ;
 155     else {
 156         fp = fopen(fname,"wb");
 157         if( !fp ) {
 158             log_error(_("error creating `%s': %s\n"), fname, strerror(errno) );
 159             rc = G10ERR_CREATE_FILE;
 160             if (errno == 106)
 161                 log_info("Do output file and input file have the same name?\n");
 162             goto leave;
 163         }
 164
 165         /* If there's a ,xxx extension in the embedded filename,
 166            use that, else check whether the user input (in fname)
 167            has a ,xxx appended, then use that in preference */
 168         if( (c = riscos_get_filetype_from_string( pt->name,
 169                                                   pt->namelen )) != -1 )
 170             filetype = c;
 171         if( (c = riscos_get_filetype_from_string( fname,
 172                                                   strlen(fname) )) != -1 )
 173             filetype = c;
 174         riscos_set_filetype_by_number(fname, filetype);
 175     }
 176 #endif /* __riscos__ */
 177
 178     if( !pt->is_partial ) {
 179         /* We have an actual length (which might be zero). */
 180
 181         if (clearsig) {
 182             log_error ("clearsig encountered while not expected\n");
 183             rc = G10ERR_UNEXPECTED;
 184             goto leave;
 185         }
 186
 187         if( convert ) { /* text mode */
 188             for( ; pt->len; pt->len-- ) {
 189                 if( (c = iobuf_get(pt->buf)) == -1 ) {
 190                     rc = gpg_error_from_syserror ();
 191                     log_error ("problem reading source (%u bytes remaining)\n",
 192                                (unsigned)pt->len);
 193                     goto leave;
 194                 }
 195                 if( mfx->md )
 196                     gcry_md_putc (mfx->md, c );
 197 #ifndef HAVE_DOSISH_SYSTEM
 198                 if( c == '\r' )  /* convert to native line ending */
 199                     continue;    /* fixme: this hack might be too simple */
 200 #endif
 201                 if( fp )
 202                   {
 203                     if(opt.max_output && (++count)>opt.max_output)
 204                       {
 205                         log_error ("error writing to `%s': %s\n",
 206                                    fname,"exceeded --max-output limit\n");
 207                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 208                         goto leave;
 209                       }
 210                     else if( putc( c, fp ) == EOF )
 211                       {
 212                         if (ferror (fp))
 213                           rc = gpg_error_from_syserror ();
 214                         else
 215                           rc = gpg_error (GPG_ERR_EOF);
 216                         log_error ("error writing to `%s': %s\n",
 217                                    fname, strerror(errno) );
 218                         goto leave;
 219                       }
 220                   }
 221             }
 222         }
 223         else { /* binary mode */
 224             byte *buffer = xmalloc( 32768 );
 225             while( pt->len ) {
 226                 int len = pt->len > 32768 ? 32768 : pt->len;
 227                 len = iobuf_read( pt->buf, buffer, len );
 228                 if( len == -1 ) {
 229                     rc = gpg_error_from_syserror ();
 230                     log_error ("problem reading source (%u bytes remaining)\n",
 231                                (unsigned)pt->len);
 232                     xfree( buffer );
 233                     goto leave;
 234                 }
 235                 if( mfx->md )
 236                     gcry_md_write ( mfx->md, buffer, len );
 237                 if( fp )
 238                   {
 239                     if(opt.max_output && (count+=len)>opt.max_output)
 240                       {
 241                         log_error ("error writing to `%s': %s\n",
 242                                    fname,"exceeded --max-output limit\n");
 243                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 244                         xfree( buffer );
 245                         goto leave;
 246                       }
 247                     else if( fwrite( buffer, 1, len, fp ) != len )
 248                       {
 249                         rc = gpg_error_from_syserror ();
 250                         log_error ("error writing to `%s': %s\n",
 251                                    fname, strerror(errno) );
 252                         xfree( buffer );
 253                         goto leave;
 254                       }
 255                   }
 256                 pt->len -= len;
 257             }
 258             xfree( buffer );
 259         }
 260     }
 261     else if( !clearsig ) {
 262         if( convert ) { /* text mode */
 263             while( (c = iobuf_get(pt->buf)) != -1 ) {
 264                 if( mfx->md )
 265                     gcry_md_putc (mfx->md, c );
 266 #ifndef HAVE_DOSISH_SYSTEM
 267                 if( convert && c == '\r' )
 268                     continue; /* fixme: this hack might be too simple */
 269 #endif
 270                 if( fp )
 271                   {
 272                     if(opt.max_output && (++count)>opt.max_output)
 273                       {
 274                         log_error("Error writing to `%s': %s\n",
 275                                   fname,"exceeded --max-output limit\n");
 276                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 277                         goto leave;
 278                       }
 279                     else if( putc( c, fp ) == EOF )
 280                       {
 281                         if ( ferror (fp ) )
 282                           rc = gpg_error_from_syserror ();
 283                         else
 284                           rc = gpg_error (GPG_ERR_EOF);
 285                         log_error("error writing to `%s': %s\n",
 286                                   fname, strerror(errno) );
 287                         goto leave;
 288                       }
 289                   }
 290             }
 291         }
 292         else { /* binary mode */
 293             byte *buffer = xmalloc( 32768 );
 294             int eof;
 295             for( eof=0; !eof; ) {
 296                 /* Why do we check for len < 32768:
 297                  * If we won't, we would practically read 2 EOFs but
 298                  * the first one has already popped the block_filter
 299                  * off and therefore we don't catch the boundary.
 300                  * So, always assume EOF if iobuf_read returns less bytes
 301                  * then requested */
 302                 int len = iobuf_read( pt->buf, buffer, 32768 );
 303                 if( len == -1 )
 304                     break;
 305                 if( len < 32768 )
 306                     eof = 1;
 307                 if( mfx->md )
 308                     gcry_md_write ( mfx->md, buffer, len );
 309                 if( fp )
 310                   {
 311                     if(opt.max_output && (count+=len)>opt.max_output)
 312                       {
 313                         log_error("error writing to `%s': %s\n",
 314                                   fname,"exceeded --max-output limit\n");
 315                         rc = gpg_error (GPG_ERR_TOO_LARGE);
 316                         xfree( buffer );
 317                         goto leave;
 318                       }
 319                     else if( fwrite( buffer, 1, len, fp ) != len ) {
 320                       rc = (errno? gpg_error_from_syserror ()
 321                             : gpg_error (GPG_ERR_INTERNAL));
 322                       log_error ("error writing to `%s': %s\n",
 323                                 fname, strerror(errno) );
 324                       xfree( buffer );
 325                       goto leave;
 326                     }
 327                   }
 328             }
 329             xfree( buffer );
 330         }
 331         pt->buf = NULL;
 332     }
 333     else {  /* clear text signature - don't hash the last cr,lf  */
 334         int state = 0;
 335
 336         while( (c = iobuf_get(pt->buf)) != -1 ) {
 337             if( fp )
 338               {
 339                 if(opt.max_output && (++count)>opt.max_output)
 340                   {
 341                     log_error ("error writing to `%s': %s\n",
 342                               fname,"exceeded --max-output limit\n");
 343                     rc = gpg_error (GPG_ERR_TOO_LARGE);
 344                     goto leave;
 345                   }
 346                 else if( putc( c, fp ) == EOF )
 347                   {
 348                     rc = (errno? gpg_error_from_syserror ()
 349                           : gpg_error (GPG_ERR_INTERNAL));
 350                     log_error ("error writing to `%s': %s\n",
 351                               fname, strerror(errno) );
 352                     goto leave;
 353                   }
 354               }
 355             if( !mfx->md )
 356                 continue;
 357             if( state == 2 ) {
 358                 gcry_md_putc (mfx->md, '\r' );
 359                 gcry_md_putc (mfx->md, '\n' );
 360                 state = 0;
 361             }
 362             if( !state ) {
 363                 if( c == '\r'  )
 364                     state = 1;
 365                 else if( c == '\n'  )
 366                     state = 2;
 367                 else
 368                     gcry_md_putc(mfx->md, c );
 369             }
 370             else if( state == 1 ) {
 371                 if( c == '\n'  )
 372                     state = 2;
 373                 else {
 374                     gcry_md_putc(mfx->md, '\r' );
 375                     if( c == '\r'  )
 376                         state = 1;
 377                     else {
 378                         state = 0;
 379                         gcry_md_putc(mfx->md, c );
 380                     }
 381                 }
 382             }
 383         }
 384         pt->buf = NULL;
 385     }
 386
 387     if( fp && fp != stdout && fclose(fp) ) {
 388         rc = (errno? gpg_error_from_syserror ()
 389               : gpg_error (GPG_ERR_INTERNAL));
 390         log_error ("error closing `%s': %s\n", fname, strerror(errno) );
 391         fp = NULL;
 392         goto leave;
 393     }
 394     fp = NULL;
 395
 396   leave:
 397     if( fp && fp != stdout )
 398         fclose(fp);
 399     xfree(fname);
 400     return rc;
 401 }
 402
 403 static void
 404 do_hash( gcry_md_hd_t md, gcry_md_hd_t md2, IOBUF fp, int textmode )
 405 {
 406     text_filter_context_t tfx;
 407     int c;
 408
 409     if( textmode ) {
 410         memset( &tfx, 0, sizeof tfx);
 411         iobuf_push_filter( fp, text_filter, &tfx );
 412     }
 413     if( md2 ) { /* work around a strange behaviour in pgp2 */
 414         /* It seems that at least PGP5 converts a single CR to a CR,LF too */
 415         int lc = -1;
 416         while( (c = iobuf_get(fp)) != -1 ) {
 417             if( c == '\n' && lc == '\r' )
 418                 gcry_md_putc (md2, c);
 419             else if( c == '\n' ) {
 420                 gcry_md_putc (md2, '\r');
 421                 gcry_md_putc (md2, c);
 422             }
 423             else if( c != '\n' && lc == '\r' ) {
 424                 gcry_md_putc (md2, '\n');
 425                 gcry_md_putc (md2, c);
 426             }
 427             else
 428                 gcry_md_putc (md2, c);
 429
 430             if( md )
 431                 gcry_md_putc (md, c );
 432             lc = c;
 433         }
 434     }
 435     else {
 436         while( (c = iobuf_get(fp)) != -1 ) {
 437             if( md )
 438                 gcry_md_putc (md, c );
 439         }
 440     }
 441 }
 442
 443
 444 /****************
 445  * Ask for the detached datafile and calculate the digest from it.
 446  * INFILE is the name of the input file.
 447  */
 448 int
 449 ask_for_detached_datafile (gcry_md_hd_t md, gcry_md_hd_t md2,
 450                            const char *inname, int textmode )
 451 {
 452     progress_filter_context_t *pfx;
 453     char *answer = NULL;
 454     IOBUF fp;
 455     int rc = 0;
 456
 457     pfx = new_progress_context ();
 458     fp = open_sigfile ( inname, pfx ); /* Open default file. */
 459
 460     if( !fp && !opt.batch ) {
 461         int any=0;
 462         tty_printf(_("Detached signature.\n"));
 463         do {
 464             char *name;
 465
 466             xfree(answer);
 467             tty_enable_completion(NULL);
 468             name = cpr_get("detached_signature.filename",
 469                            _("Please enter name of data file: "));
 470             tty_disable_completion();
 471             cpr_kill_prompt();
 472             answer=make_filename(name,(void *)NULL);
 473             xfree(name);
 474
 475             if( any && !*answer ) {
 476                 rc = gpg_error (GPG_ERR_GENERAL); /*G10ERR_READ_FILE*/
 477                 goto leave;
 478             }
 479             fp = iobuf_open(answer);
 480             if (fp && is_secured_file (iobuf_get_fd (fp)))
 481               {
 482                 iobuf_close (fp);
 483                 fp = NULL;
 484                 errno = EPERM;
 485               }
 486             if( !fp && errno == ENOENT ) {
 487                 tty_printf("No such file, try again or hit enter to quit.\n");
 488                 any++;
 489             }
 490             else if( !fp )
 491               {
 492                 rc = gpg_error_from_syserror ();
 493                 log_error(_("can't open `%s': %s\n"), answer, strerror(errno));
 494                 goto leave;
 495               }
 496         } while( !fp );
 497     }
 498
 499     if( !fp ) {
 500         if( opt.verbose )
 501             log_info(_("reading stdin ...\n"));
 502         fp = iobuf_open( NULL );
 503         assert(fp);
 504     }
 505     do_hash( md, md2, fp, textmode );
 506     iobuf_close(fp);
 507
 508   leave:
 509     xfree(answer);
 510     release_progress_context (pfx);
 511     return rc;
 512 }
 513
 514
 515
 516 /****************
 517  * Hash the given files and append the hash to hash context md.
 518  * If FILES is NULL, hash stdin.
 519  */
 520 int
 521 hash_datafiles( gcry_md_hd_t md, gcry_md_hd_t md2, strlist_t files,
 522                 const char *sigfilename, int textmode )
 523 {
 524     progress_filter_context_t *pfx;
 525     IOBUF fp;
 526     strlist_t sl;
 527
 528     pfx = new_progress_context ();
 529
 530     if( !files ) {
 531         /* check whether we can open the signed material */
 532         fp = open_sigfile( sigfilename, pfx );
 533         if( fp ) {
 534             do_hash( md, md2, fp, textmode );
 535             iobuf_close(fp);
 536             release_progress_context (pfx);
 537             return 0;
 538         }
 539         log_error (_("no signed data\n"));
 540         release_progress_context (pfx);
 541         return gpg_error (GPG_ERR_NO_DATA);
 542     }
 543
 544
 545     for (sl=files; sl; sl = sl->next ) {
 546         fp = iobuf_open( sl->d );
 547         if (fp && is_secured_file (iobuf_get_fd (fp)))
 548           {
 549             iobuf_close (fp);
 550             fp = NULL;
 551             errno = EPERM;
 552           }
 553         if( !fp ) {
 554             int rc = gpg_error_from_syserror ();
 555             log_error(_("can't open signed data `%s'\n"),
 556                                                 print_fname_stdin(sl->d));
 557             release_progress_context (pfx);
 558             return rc;
 559         }
 560         handle_progress (pfx, fp, sl->d);
 561         do_hash( md, md2, fp, textmode );
 562         iobuf_close(fp);
 563     }
 564
 565     release_progress_context (pfx);
 566     return 0;
 567 }
 568
 569
 570 /* Hash the data from file descriptor DATA_FD and append the hash to hash
 571    contexts MD and MD2.  */
 572 int
 573 hash_datafile_by_fd ( gcry_md_hd_t md, gcry_md_hd_t md2, int data_fd,
 574                       int textmode )
 575 {
 576   progress_filter_context_t *pfx = new_progress_context ();
 577   iobuf_t fp;
 578
 579   fp = iobuf_fdopen (data_fd, "rb");
 580   if (fp && is_secured_file (data_fd))
 581     {
 582       iobuf_close (fp);
 583       fp = NULL;
 584       errno = EPERM;
 585     }
 586   if ( !fp )
 587     {
 588       int rc = gpg_error_from_syserror ();
 589       log_error ( _("can't open signed data fd=%d: %s\n"),
 590                   data_fd, strerror (errno));
 591       release_progress_context (pfx);
 592       return rc;
 593     }
 594
 595   handle_progress (pfx, fp, NULL);
 596
 597   do_hash ( md, md2, fp, textmode);
 598
 599   iobuf_close(fp);
 600
 601   release_progress_context (pfx);
 602   return 0;
 603 }
 604
 605
 606 /* Set up a plaintext packet with the appropriate filename.  If there
 607    is a --set-filename, use it (it's already UTF8).  If there is a
 608    regular filename, UTF8-ize it if necessary.  If there is no
 609    filenames at all, set the field empty. */
 610
 611 PKT_plaintext *
 612 setup_plaintext_name(const char *filename,IOBUF iobuf)
 613 {
 614   PKT_plaintext *pt;
 615
 616   if(filename || opt.set_filename)
 617     {
 618       char *s;
 619
 620       if(opt.set_filename)
 621         s=make_basename(opt.set_filename,iobuf_get_real_fname(iobuf));
 622       else if(filename && !opt.flags.utf8_filename)
 623         {
 624           char *tmp=native_to_utf8(filename);
 625           s=make_basename(tmp,iobuf_get_real_fname(iobuf));
 626           xfree(tmp);
 627         }
 628       else
 629         s=make_basename(filename,iobuf_get_real_fname(iobuf));
 630
 631       pt = xmalloc (sizeof *pt + strlen(s) - 1);
 632       pt->namelen = strlen (s);
 633       memcpy (pt->name, s, pt->namelen);
 634       xfree (s);
 635     }
 636   else
 637     {
 638       /* no filename */
 639       pt = xmalloc (sizeof *pt - 1);
 640       pt->namelen = 0;
 641     }
 642
 643   return pt;
 644 }