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   (void)ctrl;
 155
 156   if (country)
 157     *country = 0;
 158
 159   fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
 160   if (!fpr)
 161     return gpg_error (GPG_ERR_GENERAL);
 162
 163   if (listfp)
 164     rewind (listfp);
 165   while (!(err = read_list (key, mycountry, &lnr)))
 166     {
 167       if (!strcmp (key, fpr))
 168         break;
 169     }
 170   if (gpg_err_code (err) == GPG_ERR_EOF)
 171     err = gpg_error (GPG_ERR_NOT_FOUND);
 172
 173   if (!err && country)
 174     strcpy (country, mycountry);
 175
 176   xfree (fpr);
 177   return err;
 178 }
 179
 180
 181 /* We know that CERT is a qualified certificate.  Ask the user for
 182    consent to actually create a signature using this certificate.
 183    Returns: 0 for yes, GPG_ERR_CANCEL for no or any otehr error
 184    code. */
 185 gpg_error_t
 186 gpgsm_qualified_consent (ctrl_t ctrl, ksba_cert_t cert)
 187 {
 188   gpg_error_t err;
 189   char *name, *subject, *buffer, *p;
 190   const char *s;
 191   char *orig_codeset = NULL;
 192
 193   name = ksba_cert_get_subject (cert, 0);
 194   if (!name)
 195     return gpg_error (GPG_ERR_GENERAL);
 196   subject = gpgsm_format_name2 (name, 0);
 197   ksba_free (name); name = NULL;
 198
 199   orig_codeset = i18n_switchto_utf8 ();
 200
 201   if (asprintf (&name,
 202                 _("You are about to create a signature using your "
 203                   "certificate:\n"
 204                   "\"%s\"\n"
 205                   "This will create a qualified signature by law "
 206                   "equated to a handwritten signature.\n\n%s%s"
 207                   "Are you really sure that you want to do this?"),
 208                 subject? subject:"?",
 209                 opt.qualsig_approval?
 210                 "":
 211                 _("Note, that this software is not officially approved "
 212                   "to create or verify such signatures.\n"),
 213                 opt.qualsig_approval? "":"\n"
 214                 ) < 0 )
 215     err = gpg_error_from_syserror ();
 216   else
 217     err = 0;
 218
 219   i18n_switchback (orig_codeset);
 220   xfree (subject);
 221
 222   if (err)
 223     return err;
 224
 225   buffer = p = xtrymalloc (strlen (name) * 3 + 1);
 226   if (!buffer)
 227     {
 228       err = gpg_error_from_syserror ();
 229       free (name);
 230       return err;
 231     }
 232   for (s=name; *s; s++)
 233     {
 234       if (*s < ' ' || *s == '+')
 235         {
 236           sprintf (p, "%%%02X", *(unsigned char *)s);
 237           p += 3;
 238         }
 239       else if (*s == ' ')
 240         *p++ = '+';
 241       else
 242         *p++ = *s;
 243     }
 244   *p = 0;
 245   free (name);
 246
 247
 248   err = gpgsm_agent_get_confirmation (ctrl, buffer);
 249
 250   xfree (buffer);
 251   return err;
 252 }
 253
 254
 255 /* Popup a prompt to inform the user that the signature created is not
 256    a qualified one.  This is of course only done if we know that we
 257    have been approved. */
 258 gpg_error_t
 259 gpgsm_not_qualified_warning (ctrl_t ctrl, ksba_cert_t cert)
 260 {
 261   gpg_error_t err;
 262   char *name, *subject, *buffer, *p;
 263   const char *s;
 264   char *orig_codeset;
 265
 266   if (!opt.qualsig_approval)
 267     return 0;
 268
 269   name = ksba_cert_get_subject (cert, 0);
 270   if (!name)
 271     return gpg_error (GPG_ERR_GENERAL);
 272   subject = gpgsm_format_name2 (name, 0);
 273   ksba_free (name); name = NULL;
 274
 275   orig_codeset = i18n_switchto_utf8 ();
 276
 277   if (asprintf (&name,
 278                 _("You are about to create a signature using your "
 279                   "certificate:\n"
 280                   "\"%s\"\n"
 281                   "Note, that this certificate will NOT create a "
 282                   "qualified signature!"),
 283                 subject? subject:"?") < 0 )
 284     err = gpg_error_from_syserror ();
 285   else
 286     err = 0;
 287
 288   i18n_switchback (orig_codeset);
 289   xfree (subject);
 290
 291   if (err)
 292     return err;
 293
 294   buffer = p = xtrymalloc (strlen (name) * 3 + 1);
 295   if (!buffer)
 296     {
 297       err = gpg_error_from_syserror ();
 298       free (name);
 299       return err;
 300     }
 301   for (s=name; *s; s++)
 302     {
 303       if (*s < ' ' || *s == '+')
 304         {
 305           sprintf (p, "%%%02X", *(unsigned char *)s);
 306           p += 3;
 307         }
 308       else if (*s == ' ')
 309         *p++ = '+';
 310       else
 311         *p++ = *s;
 312     }
 313   *p = 0;
 314   free (name);
 315
 316
 317   err = gpgsm_agent_get_confirmation (ctrl, buffer);
 318
 319   xfree (buffer);
 320   return err;
 321 }