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gnupg/g10/photoid.c

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/* 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>
#include <unistd.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. */
const char *
image_type_to_string(byte type,int style)
{
const 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))
return "xdg-open %i";
else
return "/bin/true";
#endif
}
#endif
#ifndef DISABLE_PHOTO_VIEWER
struct exec_info
{
int progreturn;
struct
{
unsigned int binary:1;
unsigned int writeonly:1;
unsigned int madedir:1;
unsigned int use_temp_files:1;
unsigned int keep_temp_files:1;
} flags;
pid_t child;
FILE *tochild;
iobuf_t fromchild;
char *command,*name,*tempdir,*tempfile_in,*tempfile_out;
};
#ifdef NO_EXEC
static int
exec_write(struct exec_info **info,const char *program,
const char *args_in,const char *name,int writeonly,int binary)
{
log_error(_("no remote program execution supported\n"));
return GPG_ERR_GENERAL;
}
static int
exec_read(struct exec_info *info) { return GPG_ERR_GENERAL; }
static int
exec_finish(struct exec_info *info) { return GPG_ERR_GENERAL; }
#else /* ! NO_EXEC */
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifndef EXEC_TEMPFILE_ONLY
#include <sys/wait.h>
#endif
#include <fcntl.h>
#include <errno.h>
#include "../common/membuf.h"
#include "../common/sysutils.h"
/* Makes a temp directory and filenames */
static int
make_tempdir(struct exec_info *info)
{
char *tmp=opt.temp_dir,*namein=info->name,*nameout;
if(!namein)
namein=info->flags.binary?"tempin" EXTSEP_S "bin":"tempin" EXTSEP_S "txt";
nameout=info->flags.binary?"tempout" EXTSEP_S "bin":"tempout" EXTSEP_S "txt";
/* Make up the temp dir and files in case we need them */
if(tmp==NULL)
{
#if defined (_WIN32)
int err;
tmp=xmalloc(MAX_PATH+2);
err=GetTempPath(MAX_PATH+1,tmp);
if(err==0 || err>MAX_PATH+1)
strcpy(tmp,"c:\\windows\\temp");
else
{
int len=strlen(tmp);
/* GetTempPath may return with \ on the end */
while(len>0 && tmp[len-1]=='\\')
{
tmp[len-1]='\0';
len--;
}
}
#else /* More unixish systems */
tmp=getenv("TMPDIR");
if(tmp==NULL)
{
tmp=getenv("TMP");
if(tmp==NULL)
{
#ifdef __riscos__
tmp="<Wimp$ScrapDir>.GnuPG";
mkdir(tmp,0700); /* Error checks occur later on */
#else
tmp="/tmp";
#endif
}
}
#endif
}
info->tempdir=xmalloc(strlen(tmp)+strlen(DIRSEP_S)+10+1);
sprintf(info->tempdir,"%s" DIRSEP_S "gpg-XXXXXX",tmp);
#if defined (_WIN32)
xfree(tmp);
#endif
if (!gnupg_mkdtemp(info->tempdir))
log_error(_("can't create directory '%s': %s\n"),
info->tempdir,strerror(errno));
else
{
info->flags.madedir=1;
info->tempfile_in=xmalloc(strlen(info->tempdir)+
strlen(DIRSEP_S)+strlen(namein)+1);
sprintf(info->tempfile_in,"%s" DIRSEP_S "%s",info->tempdir,namein);
if(!info->flags.writeonly)
{
info->tempfile_out=xmalloc(strlen(info->tempdir)+
strlen(DIRSEP_S)+strlen(nameout)+1);
sprintf(info->tempfile_out,"%s" DIRSEP_S "%s",info->tempdir,nameout);
}
}
return info->flags.madedir? 0 : GPG_ERR_GENERAL;
}
/* Expands %i and %o in the args to the full temp files within the
temp directory. */
static int
expand_args(struct exec_info *info,const char *args_in)
{
const char *ch = args_in;
membuf_t command;
info->flags.use_temp_files=0;
info->flags.keep_temp_files=0;
if(DBG_EXTPROG)
log_debug("expanding string \"%s\"\n",args_in);
init_membuf (&command, 100);
while(*ch!='\0')
{
if(*ch=='%')
{
char *append=NULL;
ch++;
switch(*ch)
{
case 'O':
info->flags.keep_temp_files=1;
/* fall through */
case 'o': /* out */
if(!info->flags.madedir)
{
if(make_tempdir(info))
goto fail;
}
append=info->tempfile_out;
info->flags.use_temp_files=1;
break;
case 'I':
info->flags.keep_temp_files=1;
/* fall through */
case 'i': /* in */
if(!info->flags.madedir)
{
if(make_tempdir(info))
goto fail;
}
append=info->tempfile_in;
info->flags.use_temp_files=1;
break;
case '%':
append="%";
break;
}
if(append)
put_membuf_str (&command, append);
}
else
put_membuf (&command, ch, 1);
ch++;
}
put_membuf (&command, "", 1); /* Terminate string. */
info->command = get_membuf (&command, NULL);
if (!info->command)
return gpg_error_from_syserror ();
if(DBG_EXTPROG)
log_debug("args expanded to \"%s\", use %u, keep %u\n",info->command,
info->flags.use_temp_files,info->flags.keep_temp_files);
return 0;
fail:
xfree (get_membuf (&command, NULL));
return GPG_ERR_GENERAL;
}
/* Either handles the tempfile creation, or the fork/exec. If it
returns ok, then info->tochild is a FILE * that can be written to.
The rules are: if there are no args, then it's a fork/exec/pipe.
If there are args, but no tempfiles, then it's a fork/exec/pipe via
shell -c. If there are tempfiles, then it's a system. */
static int
exec_write(struct exec_info **info,const char *program,
const char *args_in,const char *name,int writeonly,int binary)
{
int ret = GPG_ERR_GENERAL;
if(opt.exec_disable && !opt.no_perm_warn)
{
log_info(_("external program calls are disabled due to unsafe "
"options file permissions\n"));
return ret;
}
#if defined(HAVE_GETUID) && defined(HAVE_GETEUID)
/* There should be no way to get to this spot while still carrying
setuid privs. Just in case, bomb out if we are. */
if ( getuid () != geteuid ())
BUG ();
#endif
if(program==NULL && args_in==NULL)
BUG();
*info=xmalloc_clear(sizeof(struct exec_info));
if(name)
(*info)->name=xstrdup(name);
(*info)->flags.binary=binary;
(*info)->flags.writeonly=writeonly;
/* Expand the args, if any */
if(args_in && expand_args(*info,args_in))
goto fail;
#ifdef EXEC_TEMPFILE_ONLY
if(!(*info)->flags.use_temp_files)
{
log_error(_("this platform requires temporary files when calling"
" external programs\n"));
goto fail;
}
#else /* !EXEC_TEMPFILE_ONLY */
/* If there are no args, or there are args, but no temp files, we
can use fork/exec/pipe */
if(args_in==NULL || (*info)->flags.use_temp_files==0)
{
int to[2],from[2];
if(pipe(to)==-1)
goto fail;
if(pipe(from)==-1)
{
close(to[0]);
close(to[1]);
goto fail;
}
if(((*info)->child=fork())==-1)
{
close(to[0]);
close(to[1]);
close(from[0]);
close(from[1]);
goto fail;
}
if((*info)->child==0)
{
char *shell=getenv("SHELL");
if(shell==NULL)
shell="/bin/sh";
/* I'm the child */
/* If the program isn't going to respond back, they get to
keep their stdout/stderr */
if(!(*info)->flags.writeonly)
{
/* implied close of STDERR */
if(dup2(STDOUT_FILENO,STDERR_FILENO)==-1)
_exit(1);
/* implied close of STDOUT */
close(from[0]);
if(dup2(from[1],STDOUT_FILENO)==-1)
_exit(1);
}
/* implied close of STDIN */
close(to[1]);
if(dup2(to[0],STDIN_FILENO)==-1)
_exit(1);
if(args_in==NULL)
{
if(DBG_EXTPROG)
log_debug("execlp: %s\n",program);
execlp(program,program,(void *)NULL);
}
else
{
if(DBG_EXTPROG)
log_debug("execlp: %s -c %s\n",shell,(*info)->command);
execlp(shell,shell,"-c",(*info)->command,(void *)NULL);
}
/* If we get this far the exec failed. Clean up and return. */
if(args_in==NULL)
log_error(_("unable to execute program '%s': %s\n"),
program,strerror(errno));
else
log_error(_("unable to execute shell '%s': %s\n"),
shell,strerror(errno));
/* This mimics the POSIX sh behavior - 127 means "not found"
from the shell. */
if(errno==ENOENT)
_exit(127);
_exit(1);
}
/* I'm the parent */
close(to[0]);
(*info)->tochild=fdopen(to[1],binary?"wb":"w");
if((*info)->tochild==NULL)
{
ret = gpg_error_from_syserror ();
close(to[1]);
goto fail;
}
close(from[1]);
(*info)->fromchild=iobuf_fdopen(from[0],"r");
if((*info)->fromchild==NULL)
{
ret = gpg_error_from_syserror ();
close(from[0]);
goto fail;
}
/* fd iobufs are cached! */
iobuf_ioctl((*info)->fromchild, IOBUF_IOCTL_NO_CACHE, 1, NULL);
return 0;
}
#endif /* !EXEC_TEMPFILE_ONLY */
if(DBG_EXTPROG)
log_debug("using temp file '%s'\n",(*info)->tempfile_in);
/* It's not fork/exec/pipe, so create a temp file */
if( is_secured_filename ((*info)->tempfile_in) )
{
(*info)->tochild = NULL;
gpg_err_set_errno (EPERM);
}
else
(*info)->tochild=fopen((*info)->tempfile_in,binary?"wb":"w");
if((*info)->tochild==NULL)
{
ret = gpg_error_from_syserror ();
log_error(_("can't create '%s': %s\n"),
(*info)->tempfile_in,strerror(errno));
goto fail;
}
ret=0;
fail:
if (ret)
{
xfree (*info);
*info = NULL;
}
return ret;
}
static int
exec_read(struct exec_info *info)
{
int ret = GPG_ERR_GENERAL;
fclose(info->tochild);
info->tochild=NULL;
if(info->flags.use_temp_files)
{
if(DBG_EXTPROG)
log_debug ("running command: %s\n",info->command);
#if defined (_WIN32)
info->progreturn=w32_system(info->command);
#else
info->progreturn=system(info->command);
#endif
if(info->progreturn==-1)
{
log_error(_("system error while calling external program: %s\n"),
strerror(errno));
info->progreturn=127;
goto fail;
}
#if defined(WIFEXITED) && defined(WEXITSTATUS)
if(WIFEXITED(info->progreturn))
info->progreturn=WEXITSTATUS(info->progreturn);
else
{
log_error(_("unnatural exit of external program\n"));
info->progreturn=127;
goto fail;
}
#else
/* If we don't have the macros, do the best we can. */
info->progreturn = (info->progreturn & 0xff00) >> 8;
#endif
/* 127 is the magic value returned from system() to indicate
that the shell could not be executed, or from /bin/sh to
indicate that the program could not be executed. */
if(info->progreturn==127)
{
log_error(_("unable to execute external program\n"));
goto fail;
}
if(!info->flags.writeonly)
{
info->fromchild=iobuf_open(info->tempfile_out);
if (info->fromchild
&& is_secured_file (iobuf_get_fd (info->fromchild)))
{
iobuf_close (info->fromchild);
info->fromchild = NULL;
gpg_err_set_errno (EPERM);
}
if(info->fromchild==NULL)
{
ret = gpg_error_from_syserror ();
log_error(_("unable to read external program response: %s\n"),
strerror(errno));
goto fail;
}
/* Do not cache this iobuf on close */
iobuf_ioctl(info->fromchild, IOBUF_IOCTL_NO_CACHE, 1, NULL);
}
}
ret=0;
fail:
return ret;
}
static int
exec_finish(struct exec_info *info)
{
int ret=info->progreturn;
if(info->fromchild)
iobuf_close(info->fromchild);
if(info->tochild)
fclose(info->tochild);
#ifndef EXEC_TEMPFILE_ONLY
if(info->child>0)
{
if(waitpid(info->child,&info->progreturn,0)!=0 &&
WIFEXITED(info->progreturn))
ret=WEXITSTATUS(info->progreturn);
else
{
log_error(_("unnatural exit of external program\n"));
ret=127;
}
}
#endif
if(info->flags.madedir && !info->flags.keep_temp_files)
{
if(info->tempfile_in)
{
if(unlink(info->tempfile_in)==-1)
log_info(_("WARNING: unable to remove tempfile (%s) '%s': %s\n"),
"in",info->tempfile_in,strerror(errno));
}
if(info->tempfile_out)
{
if(unlink(info->tempfile_out)==-1)
log_info(_("WARNING: unable to remove tempfile (%s) '%s': %s\n"),
"out",info->tempfile_out,strerror(errno));
}
if(rmdir(info->tempdir)==-1)
log_info(_("WARNING: unable to remove temp directory '%s': %s\n"),
info->tempdir,strerror(errno));
}
xfree(info->command);
xfree(info->name);
xfree(info->tempdir);
xfree(info->tempfile_in);
xfree(info->tempfile_out);
xfree(info);
return ret;
}
#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;
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*/
}
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