gnupg/g10/photoid.c

/* photoid.c - photo ID handling code
 * Copyright (C) 2001, 2002, 2005, 2006, 2008, 2011 Free Software Foundation, Inc.
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuPG 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#ifdef _WIN32
# ifdef HAVE_WINSOCK2_H
#  include <winsock2.h>
# endif
# include <windows.h>
# ifndef VER_PLATFORM_WIN32_WINDOWS
#  define VER_PLATFORM_WIN32_WINDOWS 1
# endif
#endif

#include "gpg.h"
#include "../common/util.h"
#include "packet.h"
#include "../common/status.h"
#include "exec.h"
#include "keydb.h"
#include "../common/i18n.h"
#include "../common/iobuf.h"
#include "options.h"
#include "main.h"
#include "photoid.h"
#include "../common/ttyio.h"
#include "trustdb.h"

/* Generate a new photo id packet, or return NULL if canceled.
   FIXME:  Should we add a duplicates check similar to generate_user_id? */
PKT_user_id *
generate_photo_id (ctrl_t ctrl, PKT_public_key *pk,const char *photo_name)
{
  PKT_user_id *uid;
  int error=1,i;
  unsigned int len;
  char *filename;
  byte *photo=NULL;
  byte header[16];
  IOBUF file;
  int overflow;

  header[0]=0x10; /* little side of photo header length */
  header[1]=0;    /* big side of photo header length */
  header[2]=1;    /* 1 == version of photo header */
  header[3]=1;    /* 1 == JPEG */

  for(i=4;i<16;i++) /* The reserved bytes */
    header[i]=0;

#define EXTRA_UID_NAME_SPACE 71
  uid=xmalloc_clear(sizeof(*uid)+71);

  if(photo_name && *photo_name)
    filename=make_filename(photo_name,(void *)NULL);
  else
    {
      tty_printf(_("\nPick an image to use for your photo ID."
		   "  The image must be a JPEG file.\n"
		   "Remember that the image is stored within your public key."
		   "  If you use a\n"
		   "very large picture, your key will become very large"
		   " as well!\n"
		   "Keeping the image close to 240x288 is a good size"
		   " to use.\n"));
      filename=NULL;
    }

  while(photo==NULL)
    {
      if(filename==NULL)
	{
	  char *tempname;

	  tty_printf("\n");

	  tty_enable_completion(NULL);

	  tempname=cpr_get("photoid.jpeg.add",
			   _("Enter JPEG filename for photo ID: "));

	  tty_disable_completion();

	  filename=make_filename(tempname,(void *)NULL);

	  xfree(tempname);

	  if(strlen(filename)==0)
	    goto scram;
	}

      file=iobuf_open(filename);
      if (file && is_secured_file (iobuf_get_fd (file)))
        {
          iobuf_close (file);
          file = NULL;
          gpg_err_set_errno (EPERM);
        }
      if(!file)
	{
	  log_error(_("unable to open JPEG file '%s': %s\n"),
		    filename,strerror(errno));
	  xfree(filename);
	  filename=NULL;
	  continue;
	}


      len=iobuf_get_filelength(file, &overflow);
      if(len>6144 || overflow)
	{
	  tty_printf( _("This JPEG is really large (%d bytes) !\n"),len);
	  if(!cpr_get_answer_is_yes("photoid.jpeg.size",
			    _("Are you sure you want to use it? (y/N) ")))
	  {
	    iobuf_close(file);
	    xfree(filename);
	    filename=NULL;
	    continue;
	  }
	}

      photo=xmalloc(len);
      iobuf_read(file,photo,len);
      iobuf_close(file);

      /* Is it a JPEG? */
      if(photo[0]!=0xFF || photo[1]!=0xD8)
	{
	  log_error(_("'%s' is not a JPEG file\n"),filename);
	  xfree(photo);
	  photo=NULL;
	  xfree(filename);
	  filename=NULL;
	  continue;
	}

      /* Build the packet */
      build_attribute_subpkt(uid,1,photo,len,header,16);
      parse_attribute_subpkts(uid);
      make_attribute_uidname(uid, EXTRA_UID_NAME_SPACE);

      /* Showing the photo is not safe when noninteractive since the
         "user" may not be able to dismiss a viewer window! */
      if(opt.command_fd==-1)
	{
	  show_photos (ctrl, uid->attribs, uid->numattribs, pk, uid);
	  switch(cpr_get_answer_yes_no_quit("photoid.jpeg.okay",
					 _("Is this photo correct (y/N/q)? ")))
	    {
	    case -1:
	      goto scram;
	    case 0:
	      free_attributes(uid);
	      xfree(photo);
	      photo=NULL;
	      xfree(filename);
	      filename=NULL;
	      continue;
	    }
	}
    }

  error=0;
  uid->ref=1;

 scram:
  xfree(filename);
  xfree(photo);

  if(error)
    {
      free_attributes(uid);
      xfree(uid);
      return NULL;
    }

  return uid;
}

/* Returns 0 for error, 1 for valid */
int parse_image_header(const struct user_attribute *attr,byte *type,u32 *len)
{
  u16 headerlen;

  if(attr->len<3)
    return 0;

  /* For historical reasons (i.e. "oops!"), the header length is
     little endian. */
  headerlen=(attr->data[1]<<8) | attr->data[0];

  if(headerlen>attr->len)
    return 0;

  if(type && attr->len>=4)
    {
      if(attr->data[2]==1) /* header version 1 */
	*type=attr->data[3];
      else
	*type=0;
    }

  *len=attr->len-headerlen;

  if(*len==0)
    return 0;

  return 1;
}

/* style==0 for extension, 1 for name, 2 for MIME type.  Remember that
   the "name" style string could be used in a user ID name field, so
   make sure it is not too big (see parse-packet.c:parse_attribute).
   Extensions should be 3 characters long for the best cross-platform
   compatibility. */
char *image_type_to_string(byte type,int style)
{
  char *string;

  switch(type)
    {
    case 1: /* jpeg */
      if(style==0)
	string="jpg";
      else if(style==1)
	string="jpeg";
      else
	string="image/jpeg";
      break;

    default:
      if(style==0)
	string="bin";
      else if(style==1)
	string="unknown";
      else
	string="image/x-unknown";
      break;
    }

  return string;
}

#if !defined(FIXED_PHOTO_VIEWER) && !defined(DISABLE_PHOTO_VIEWER)
static const char *
get_default_photo_command(void)
{
#if defined(_WIN32)
  OSVERSIONINFO osvi;

  memset(&osvi,0,sizeof(osvi));
  osvi.dwOSVersionInfoSize=sizeof(osvi);
  GetVersionEx(&osvi);

  if(osvi.dwPlatformId==VER_PLATFORM_WIN32_WINDOWS)
    return "start /w %i";
  else
    return "!ShellExecute 400 %i";
#elif defined(__APPLE__)
  /* OS X.  This really needs more than just __APPLE__. */
  return "open %I";
#elif defined(__riscos__)
  return "Filer_Run %I";
#else
  if (!path_access ("xloadimage", X_OK))
    return "xloadimage -fork -quiet -title 'KeyID 0x%k' stdin";
  else if (!path_access ("display",X_OK))
    return "display -title 'KeyID 0x%k' %i";
  else if (getuid () && !path_access ("xdg-open", X_OK))
    {
      /* xdg-open spawns the actual program and exits so we need to
       * keep the temp file */
      return "xdg-open %I";
    }
  else
    return "/bin/true";
#endif
}
#endif


void
show_photos (ctrl_t ctrl, const struct user_attribute *attrs, int count,
             PKT_public_key *pk, PKT_user_id *uid)
{
#ifdef DISABLE_PHOTO_VIEWER
  (void)attrs;
  (void)count;
  (void)pk;
  (void)uid;
#else /*!DISABLE_PHOTO_VIEWER*/
  int i;
  struct expando_args args;
  u32 len;
  u32 kid[2]={0,0};

  memset (&args, 0, sizeof(args));
  args.pk = pk;
  args.validity_info = get_validity_info (ctrl, NULL, pk, uid);
  args.validity_string = get_validity_string (ctrl, pk, uid);
  namehash_from_uid (uid);
  args.namehash = uid->namehash;

  if (pk)
    keyid_from_pk (pk, kid);

  es_fflush (es_stdout);

  for(i=0;i<count;i++)
    if(attrs[i].type==ATTRIB_IMAGE &&
       parse_image_header(&attrs[i],&args.imagetype,&len))
      {
	char *command,*name;
	struct exec_info *spawn;
	int offset=attrs[i].len-len;

#ifdef FIXED_PHOTO_VIEWER
	opt.photo_viewer=FIXED_PHOTO_VIEWER;
#else
	if(!opt.photo_viewer)
	  opt.photo_viewer=get_default_photo_command();
#endif

	/* make command grow */
	command=pct_expando(opt.photo_viewer,&args);
	if(!command)
	  goto fail;
        if (!*command)
          {
            xfree (command);
            goto fail;
          }

	name=xmalloc(16+strlen(EXTSEP_S)+
		     strlen(image_type_to_string(args.imagetype,0))+1);

	/* Make the filename.  Notice we are not using the image
           encoding type for more than cosmetics.  Most external image
           viewers can handle a multitude of types, and even if one
           cannot understand a particular type, we have no way to know
           which.  The spec permits this, by the way. -dms */

#ifdef USE_ONLY_8DOT3
	sprintf(name,"%08lX" EXTSEP_S "%s",(ulong)kid[1],
		image_type_to_string(args.imagetype,0));
#else
	sprintf(name,"%08lX%08lX" EXTSEP_S "%s",(ulong)kid[0],(ulong)kid[1],
		image_type_to_string(args.imagetype,0));
#endif

	if(exec_write(&spawn,NULL,command,name,1,1)!=0)
	  {
	    xfree(name);
	    goto fail;
	  }

#ifdef __riscos__
        riscos_set_filetype_by_mimetype(spawn->tempfile_in,
                                        image_type_to_string(args.imagetype,2));
#endif

	xfree(name);

	fwrite(&attrs[i].data[offset],attrs[i].len-offset,1,spawn->tochild);

	if(exec_read(spawn)!=0)
	  {
	    exec_finish(spawn);
	    goto fail;
	  }

	if(exec_finish(spawn)!=0)
	  goto fail;
      }

  return;

 fail:
  log_error(_("unable to display photo ID!\n"));
#endif /*!DISABLE_PHOTO_VIEWER*/
}