sm/qualified.c

   1 /* qualified.c - Routines related to qualified signatures
   2  * Copyright (C) 2005, 2007 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuPG.
   5  *
   6  * GnuPG is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuPG is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <config.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <stdarg.h>
  25 #include <assert.h>
  26 #include <errno.h>
  27
  28 #include "gpgsm.h"
  29 #include "i18n.h"
  30 #include <ksba.h>
  31
  32
  33 /* We open the file only once and keep the open file pointer as well
  34    as the name of the file here.  Note that, a listname not equal to
  35    NULL indicates that this module has been intialized and if the
  36    LISTFP is also NULL, no list of qualified signatures exists. */
  37 static char *listname;
  38 static FILE *listfp;
  39
  40
  41 /* Read the trustlist and return entry by entry.  KEY must point to a
  42    buffer of at least 41 characters. COUNTRY shall be a buffer of at
  43    least 3 characters to receive the country code of that qualified
  44    signature (i.e. "de" for German and "be" for Belgium).
  45
  46    Reading a valid entry returns 0, EOF is indicated by GPG_ERR_EOF
  47    and any other error condition is indicated by the appropriate error
  48    code. */
  49 static gpg_error_t
  50 read_list (char *key, char *country, int *lnr)
  51 {
  52   gpg_error_t err;
  53   int c, i, j;
  54   char *p, line[256];
  55
  56   *key = 0;
  57   *country = 0;
  58
  59   if (!listname)
  60     {
  61       listname = make_filename (gnupg_datadir (), "qualified.txt", NULL);
  62       listfp = fopen (listname, "r");
  63       if (!listfp && errno != ENOENT)
  64         {
  65           err = gpg_error_from_syserror ();
  66           log_error (_("can't open `%s': %s\n"), listname, gpg_strerror (err));
  67           return err;
  68         }
  69     }
  70
  71   if (!listfp)
  72     return gpg_error (GPG_ERR_EOF);
  73
  74   do
  75     {
  76       if (!fgets (line, DIM(line)-1, listfp) )
  77         {
  78           if (feof (listfp))
  79             return gpg_error (GPG_ERR_EOF);
  80           return gpg_error_from_syserror ();
  81         }
  82
  83       if (!*line || line[strlen(line)-1] != '\n')
  84         {
  85           /* Eat until end of line. */
  86           while ( (c=getc (listfp)) != EOF && c != '\n')
  87             ;
  88           return gpg_error (*line? GPG_ERR_LINE_TOO_LONG
  89                                  : GPG_ERR_INCOMPLETE_LINE);
  90         }
  91       ++*lnr;
  92
  93       /* Allow for empty lines and spaces */
  94       for (p=line; spacep (p); p++)
  95         ;
  96     }
  97   while (!*p || *p == '\n' || *p == '#');
  98
  99   for (i=j=0; (p[i] == ':' || hexdigitp (p+i)) && j < 40; i++)
 100     if ( p[i] != ':' )
 101       key[j++] = p[i] >= 'a'? (p[i] & 0xdf): p[i];
 102   key[j] = 0;
 103   if (j != 40 || !(spacep (p+i) || p[i] == '\n'))
 104     {
 105       log_error (_("invalid formatted fingerprint in `%s', line %d\n"),
 106                  listname, *lnr);
 107       return gpg_error (GPG_ERR_BAD_DATA);
 108     }
 109   assert (p[i]);
 110   i++;
 111   while (spacep (p+i))
 112     i++;
 113   if ( p[i] >= 'a' && p[i] <= 'z'
 114        && p[i+1] >= 'a' && p[i+1] <= 'z'
 115        && (spacep (p+i+2) || p[i+2] == '\n'))
 116     {
 117       country[0] = p[i];
 118       country[1] = p[i+1];
 119       country[2] = 0;
 120     }
 121   else
 122     {
 123       log_error (_("invalid country code in `%s', line %d\n"), listname, *lnr);
 124       return gpg_error (GPG_ERR_BAD_DATA);
 125     }
 126
 127   return 0;
 128 }
 129
 130
 131
 132
 133 /* Check whether the certificate CERT is included in the list of
 134    qualified certificates.  This list is similar to the "trustlist.txt"
 135    as maintained by gpg-agent and includes fingerprints of root
 136    certificates to be used for qualified (legally binding like
 137    handwritten) signatures.  We keep this list system wide and not
 138    per user because it is not a decision of the user.
 139
 140    Returns: 0 if the certificate is included.  GPG_ERR_NOT_FOUND if it
 141    is not in the list or any other error (e.g. if no list of
 142    qualified signatures is available.  If COUNTRY has not been passed
 143    as NULL a string witha maximum length of 2 will be copied into it;
 144    thus the caller needs to provide a buffer of length 3. */
 145 gpg_error_t
 146 gpgsm_is_in_qualified_list (ctrl_t ctrl, ksba_cert_t cert, char *country)
 147 {
 148   gpg_error_t err;
 149   char *fpr;
 150   char key[41];
 151   char mycountry[3];
 152   int lnr = 0;
 153
 154   if (country)
 155     *country = 0;
 156
 157   fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 158   if (!fpr)
 159     return gpg_error (GPG_ERR_GENERAL);
 160
 161   if (listfp)
 162     rewind (listfp);
 163   while (!(err = read_list (key, mycountry, &lnr)))
 164     {
 165       if (!strcmp (key, fpr))
 166         break;
 167     }
 168   if (gpg_err_code (err) == GPG_ERR_EOF)
 169     err = gpg_error (GPG_ERR_NOT_FOUND);
 170
 171   if (!err && country)
 172     strcpy (country, mycountry);
 173
 174   xfree (fpr);
 175   return err;
 176 }
 177
 178
 179 /* We know that CERT is a qualified certificate.  Ask the user for
 180    consent to actually create a signature using this certificate.
 181    Returns: 0 for yes, GPG_ERR_CANCEL for no or any otehr error
 182    code. */
 183 gpg_error_t
 184 gpgsm_qualified_consent (ctrl_t ctrl, ksba_cert_t cert)
 185 {
 186   gpg_error_t err;
 187   char *name, *subject, *buffer, *p;
 188   const char *s;
 189   char *orig_codeset = NULL;
 190
 191   name = ksba_cert_get_subject (cert, 0);
 192   if (!name)
 193     return gpg_error (GPG_ERR_GENERAL);
 194   subject = gpgsm_format_name2 (name, 0);
 195   ksba_free (name); name = NULL;
 196
 197   orig_codeset = i18n_switchto_utf8 ();
 198
 199   if (asprintf (&name,
 200                 _("You are about to create a signature using your "
 201                   "certificate:\n"
 202                   "\"%s\"\n"
 203                   "This will create a qualified signature by law "
 204                   "equated to a handwritten signature.\n\n%s%s"
 205                   "Are you really sure that you want to do this?"),
 206                 subject? subject:"?",
 207                 opt.qualsig_approval?
 208                 "":
 209                 _("Note, that this software is not officially approved "
 210                   "to create or verify such signatures.\n"),
 211                 opt.qualsig_approval? "":"\n"
 212                 ) < 0 )
 213     err = gpg_error_from_syserror ();
 214   else
 215     err = 0;
 216
 217   i18n_switchback (orig_codeset);
 218   xfree (orig_codeset);
 219   xfree (subject);
 220
 221   if (err)
 222     return err;
 223
 224   buffer = p = xtrymalloc (strlen (name) * 3 + 1);
 225   if (!buffer)
 226     {
 227       err = gpg_error_from_syserror ();
 228       free (name);
 229       return err;
 230     }
 231   for (s=name; *s; s++)
 232     {
 233       if (*s < ' ' || *s == '+')
 234         {
 235           sprintf (p, "%%%02X", *(unsigned char *)s);
 236           p += 3;
 237         }
 238       else if (*s == ' ')
 239         *p++ = '+';
 240       else
 241         *p++ = *s;
 242     }
 243   *p = 0;
 244   free (name);
 245
 246
 247   err = gpgsm_agent_get_confirmation (ctrl, buffer);
 248
 249   xfree (buffer);
 250   return err;
 251 }
 252
 253
 254 /* Popup a prompt to inform the user that the signature created is not
 255    a qualified one.  This is of course only done if we know that we
 256    have been approved. */
 257 gpg_error_t
 258 gpgsm_not_qualified_warning (ctrl_t ctrl, ksba_cert_t cert)
 259 {
 260   gpg_error_t err;
 261   char *name, *subject, *buffer, *p;
 262   const char *s;
 263   char *orig_codeset;
 264
 265   if (!opt.qualsig_approval)
 266     return 0;
 267
 268   name = ksba_cert_get_subject (cert, 0);
 269   if (!name)
 270     return gpg_error (GPG_ERR_GENERAL);
 271   subject = gpgsm_format_name2 (name, 0);
 272   ksba_free (name); name = NULL;
 273
 274   orig_codeset = i18n_switchto_utf8 ();
 275
 276   if (asprintf (&name,
 277                 _("You are about to create a signature using your "
 278                   "certificate:\n"
 279                   "\"%s\"\n"
 280                   "Note, that this certificate will NOT create a "
 281                   "qualified signature!"),
 282                 subject? subject:"?") < 0 )
 283     err = gpg_error_from_syserror ();
 284   else
 285     err = 0;
 286
 287   i18n_switchback (orig_codeset);
 288   xfree (subject);
 289
 290   if (err)
 291     return err;
 292
 293   buffer = p = xtrymalloc (strlen (name) * 3 + 1);
 294   if (!buffer)
 295     {
 296       err = gpg_error_from_syserror ();
 297       free (name);
 298       return err;
 299     }
 300   for (s=name; *s; s++)
 301     {
 302       if (*s < ' ' || *s == '+')
 303         {
 304           sprintf (p, "%%%02X", *(unsigned char *)s);
 305           p += 3;
 306         }
 307       else if (*s == ' ')
 308         *p++ = '+';
 309       else
 310         *p++ = *s;
 311     }
 312   *p = 0;
 313   free (name);
 314
 315
 316   err = gpgsm_agent_get_confirmation (ctrl, buffer);
 317
 318   xfree (buffer);
 319   return err;
 320 }