scd/card-dinsig.c

   1 /* card-dinsig.c - German signature law (DINSIG) functions
   2  *      Copyright (C) 2002 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 /* The German signature law and its bylaw (SigG and SigV) is currently
  21    used with an interface specification described in DIN V 66291-1.
  22    The AID to be used is: 'D27600006601'.
  23
  24    The file IDs for certificates utilize the generic format:
  25         Cxyz
  26     C being the hex digit 'C' (12).
  27     x being the service indicator:
  28          '0' := SigG conform digital signature.
  29          '1' := entity authentication.
  30          '2' := key encipherment.
  31          '3' := data encipherment.
  32          '4' := key agreement.
  33          other values are reserved for future use.
  34     y being the security environment number using '0' for cards
  35       not supporting a SE number.
  36     z being the certificate type:
  37          '0'        := C.CH (base certificate of ard holder) or C.ICC.
  38          '1' .. '7' := C.CH (business or professional certificate
  39                        of card holder.
  40          '8' .. 'D' := C.CA (certificate of a CA issue by the Root-CA).
  41          'E'        := C.RCA (self certified certificate of the Root-CA).
  42          'F'        := reserved.
  43
  44    The file IDs used by default are:
  45    '1F00'  EF.SSD (security service descriptor). [o,o]
  46    '2F02'  EF.GDO (global data objects) [m,m]
  47    'A000'  EF.PROT (signature log).  Cyclic file with 20 records of 53 byte.
  48            Read and update after user authentication. [o,o]
  49    'B000'  EF.PK.RCA.DS (public keys of Root-CA).  Size is 512b or size
  50            of keys. [m (unless a 'C00E' is present),m]
  51    'B001'  EF.PK.CA.DS (public keys of CAs).  Size is 512b or size
  52            of keys. [o,o]
  53    'C00n'  EF.C.CH.DS (digital signature certificate of card holder)
  54            with n := 0 .. 7.  Size is 2k or size of cert.  Read and
  55            update allowed after user authentication. [m,m]
  56    'C00m'  EF.C.CA.DS (digital signature certificate of CA)
  57            with m := 8 .. E.  Size is 1k or size of cert.  Read always
  58            allowed, update after uder authentication. [o,o]
  59    'C100'  EF.C.ICC.AUT (AUT certificate of ICC) [o,m]
  60    'C108'  EF.C.CA.AUT (AUT certificate of CA) [o,m]
  61    'D000'  EF.DM (display message) [-,m]
  62
  63    The letters in brackets indicate optional or mandatory files: The
  64    first for card terminals under full control and the second for
  65    "business" card terminals.
  66
  67    FIXME: Needs a lot more explanation.
  68
  69 */
  70
  71
  72 #include <config.h>
  73 #include <errno.h>
  74 #include <stdio.h>
  75 #include <stdlib.h>
  76 #include <string.h>
  77 #include <time.h>
  78
  79 #ifdef HAVE_OPENSC
  80 #include <opensc/pkcs15.h>
  81 #include "scdaemon.h"
  82 #include <ksba.h>
  83
  84 #include "card-common.h"
  85
  86 static int dinsig_read_cert (CARD card, const char *certidstr,
  87                              unsigned char **cert, size_t *ncert);
  88
  89
  90
  91 /* See card.c for interface description.  Frankly we don't do any real
  92    enumeration but just check whether the well know files are
  93    available.  */
  94 static int
  95 dinsig_enum_keypairs (CARD card, int idx,
  96                       unsigned char *keygrip, char **keyid)
  97 {
  98   int rc;
  99   unsigned char *buf;
 100   size_t buflen;
 101   ksba_cert_t cert;
 102
 103   /* fixme: We should locate the application via the EF(DIR) and not
 104      assume a Netkey card */
 105   if (!idx)
 106     rc = dinsig_read_cert (card, "DINSIG-DF01.C000", &buf, &buflen);
 107   else if (idx == 1)
 108     rc = dinsig_read_cert (card, "DINSIG-DF01.C200", &buf, &buflen);
 109   else
 110     rc = -1;
 111   if (rc)
 112     return rc;
 113
 114   rc = ksba_cert_new (&cert);
 115   if (rc)
 116     {
 117       xfree (buf);
 118       return rc;
 119     }
 120
 121   rc = ksba_cert_init_from_mem (cert, buf, buflen);
 122   xfree (buf);
 123   if (rc)
 124     {
 125       log_error ("failed to parse the certificate at idx %d: %s\n",
 126                  idx, gpg_strerror (rc));
 127       ksba_cert_release (cert);
 128       return rc;
 129     }
 130   if (card_help_get_keygrip (cert, keygrip))
 131     {
 132       log_error ("failed to calculate the keygrip at index %d\n", idx);
 133       ksba_cert_release (cert);
 134       return gpg_error (GPG_ERR_CARD);
 135     }
 136   ksba_cert_release (cert);
 137
 138   /* return the iD */
 139   if (keyid)
 140     {
 141       *keyid = xtrymalloc (17);
 142       if (!*keyid)
 143         return gpg_error (gpg_err_code_from_errno (errno));
 144       if (!idx)
 145         strcpy (*keyid, "DINSIG-DF01.C000");
 146       else
 147         strcpy (*keyid, "DINSIG-DF01.C200");
 148     }
 149
 150   return 0;
 151 }
 152
 153
 154 \f
 155 /* See card.c for interface description */
 156 static int
 157 dinsig_read_cert (CARD card, const char *certidstr,
 158                   unsigned char **cert, size_t *ncert)
 159 {
 160   int rc;
 161   struct sc_path path;
 162   struct sc_file *file;
 163   unsigned char *buf;
 164   int buflen;
 165
 166   if (!strcmp (certidstr, "DINSIG-DF01.C000"))
 167     sc_format_path ("3F00DF01C000", &path);
 168   else if (!strcmp (certidstr, "DINSIG-DF01.C200"))
 169     sc_format_path ("3F00DF01C200", &path);
 170   else
 171     return gpg_error (GPG_ERR_INV_ID);
 172
 173   rc = sc_select_file (card->scard, &path, &file);
 174   if (rc)
 175     {
 176       log_error ("sc_select_file failed: %s\n", sc_strerror (rc));
 177       return map_sc_err (rc);
 178     }
 179   if (file->type != SC_FILE_TYPE_WORKING_EF
 180       || file->ef_structure != SC_FILE_EF_TRANSPARENT)
 181     {
 182       log_error ("wrong type or structure of certificate EF\n");
 183       sc_file_free (file);
 184       return gpg_error (GPG_ERR_CARD);
 185     }
 186   if (file->size < 20) /* check against a somewhat arbitrary length */
 187     {
 188       log_error ("certificate EF too short\n");
 189       sc_file_free (file);
 190       return gpg_error (GPG_ERR_CARD);
 191     }
 192   buf = xtrymalloc (file->size);
 193   if (!buf)
 194     {
 195       gpg_error_t tmperr = gpg_error (gpg_err_code_from_errno (errno));
 196       sc_file_free (file);
 197       return tmperr;
 198     }
 199
 200   rc = sc_read_binary (card->scard, 0, buf, file->size, 0);
 201   if (rc >= 0 && rc != file->size)
 202     {
 203       log_error ("short read on certificate EF\n");
 204       sc_file_free (file);
 205       xfree (buf);
 206       return gpg_error (GPG_ERR_CARD);
 207     }
 208   sc_file_free (file);
 209   if (rc < 0)
 210     {
 211       log_error ("error reading certificate EF: %s\n", sc_strerror (rc));
 212       xfree (buf);
 213       return map_sc_err (rc);
 214     }
 215   buflen = rc;
 216
 217   /* The object is not a plain certificate but wrapped into id-at
 218      userCertificate - fixme: we should check the specs and decided
 219      whether libksba should support it */
 220   if (buflen > 9 && buf[0] == 0x30 && buf[4] == 6 && buf[5] == 3
 221       && buf[6] == 0x55 && buf[7] == 4 && buf[8] == 0x24)
 222     {
 223       /* We have to strip the padding.  Although this is a good idea
 224          anyway, we have to do it due to a KSBA problem; KSBA does not
 225          work correct when the buffer is larger than the ASN.1
 226          structure and the certificates here are padded with FF.  So
 227          as a workaround we look at the outer structure to get the
 228          size of the entire thing and adjust the buflen.  We can only
 229          do this when there is a 2 byte length field */
 230       size_t seqlen;
 231       if (buf[1] == 0x82)
 232         {
 233           seqlen = ((buf[2] << 8) | buf[3]) + 4;
 234           if (seqlen < buflen)
 235             buflen = seqlen;
 236         }
 237       memmove (buf, buf+9, buflen-9);
 238       buflen -= 9;
 239     }
 240
 241   *cert = buf;
 242   *ncert = buflen;
 243   return 0;
 244 }
 245
 246
 247
 248
 249 /* Bind our operations to the card */
 250 void
 251 card_dinsig_bind (CARD card)
 252 {
 253   card->fnc.enum_keypairs = dinsig_enum_keypairs;
 254   card->fnc.read_cert     = dinsig_read_cert;
 255
 256 }
 257 #endif /*HAVE_OPENSC*/