Added qualified signature features.

sm/qualified.c

@@ -0,0 +1,264 @@
+/* qualified.c - Routines related to qualified signatures
+ * Copyright (C) 2005 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <assert.h>
+#include <errno.h>
+#ifdef HAVE_LOCALE_H
+#include <locale.h>
+#endif
+#ifdef HAVE_LANGINFO_CODESET
+#include <langinfo.h>
+#endif
+
+#include "gpgsm.h"
+#include "i18n.h"
+#include <ksba.h>
+
+
+/* We open the file only once and keep the open file pointer as well
+   as the name of the file here.  Note that, a listname not equal to
+   NULL indicates that this module has been intialized and if the
+   LISTFP is also NULL, no list of qualified signatures exists. */
+static char *listname;
+static FILE *listfp;
+
+
+/* Read the trustlist and return entry by entry.  KEY must point to a
+   buffer of at least 41 characters. COUNTRY shall be a buffer of at
+   least 3 characters to receive the country code of that qualified
+   signature (i.e. "de" for German and "be" for Belgium).
+
+   Reading a valid entry returns 0, EOF is indicated by GPG_ERR_EOF
+   and any other error condition is indicated by the appropriate error
+   code. */
+static gpg_error_t
+read_list (char *key, char *country, int *lnr)
+{
+  gpg_error_t err;
+  int c, i, j;
+  char *p, line[256];
+
+  *key = 0;
+  *country = 0;
+
+  if (!listname)
+    {
+      listname = make_filename (GNUPG_DATADIR, "qualified.txt", NULL);
+      listfp = fopen (listname, "r");
+      if (!listfp && errno != ENOENT)
+        {
+          err = gpg_error_from_errno (errno);
+          log_error (_("can't open `%s': %s\n"), listname, gpg_strerror (err));
+          return err;
+        }
+    }
+
+  if (!listfp)
+    return gpg_error (GPG_ERR_EOF);
+
+  do
+    {
+      if (!fgets (line, DIM(line)-1, listfp) )
+        {
+          if (feof (listfp))
+            return gpg_error (GPG_ERR_EOF);
+          return gpg_error_from_errno (errno);
+        }
+
+      if (!*line || line[strlen(line)-1] != '\n')
+        {
+          /* Eat until end of line. */
+          while ( (c=getc (listfp)) != EOF && c != '\n')
+            ;
+          return gpg_error (*line? GPG_ERR_LINE_TOO_LONG
+                                 : GPG_ERR_INCOMPLETE_LINE);
+        }
+      ++*lnr;
+      
+      /* Allow for empty lines and spaces */
+      for (p=line; spacep (p); p++)
+        ;
+    }
+  while (!*p || *p == '\n' || *p == '#');
+  
+  for (i=j=0; (p[i] == ':' || hexdigitp (p+i)) && j < 40; i++)
+    if ( p[i] != ':' )
+      key[j++] = p[i] >= 'a'? (p[i] & 0xdf): p[i];
+  key[j] = 0;
+  if (j != 40 || !(spacep (p+i) || p[i] == '\n'))
+    {
+      log_error (_("invalid formatted fingerprint in `%s', line %d\n"),
+                 listname, *lnr);
+      return gpg_error (GPG_ERR_BAD_DATA);
+    }
+  assert (p[i]);
+  i++;
+  while (spacep (p+i))
+    i++;
+  if ( p[i] >= 'a' && p[i] <= 'z' 
+       && p[i+1] >= 'a' && p[i+1] <= 'z' 
+       && (spacep (p+i+2) || p[i+2] == '\n'))
+    {
+      country[0] = p[i];
+      country[1] = p[i+1];
+      country[2] = 0;
+    }
+  else
+    {
+      log_error (_("invalid country code in `%s', line %d\n"), listname, *lnr);
+      return gpg_error (GPG_ERR_BAD_DATA);
+    }
+
+  return 0;
+}
+
+
+
+
+/* Check whether the certificate CERT is included in the list of
+   qualified certificates.  This list is similar to the "trustlist.txt"
+   as maintained by gpg-agent and includes fingerprints of root
+   certificates to be used for qualified (legally binding like
+   handwritten) signatures.  We keep this list system wide and not
+   per user because it is not a decision of the user. 
+
+   Returns: 0 if the certificate is included.  GPG_ERR_NOT_FOUND if it
+   is not in the liost or any other error (e.g. if no list of
+   qualified signatures is available. */
+gpg_error_t
+gpgsm_is_in_qualified_list (ctrl_t ctrl, ksba_cert_t cert)
+{
+  gpg_error_t err;
+  char *fpr;
+  char key[41];
+  char country[2];
+  int lnr = 0;
+
+  fpr = gpgsm_get_fingerprint_hexstring (cert, GCRY_MD_SHA1);
+  if (!fpr)
+    return gpg_error (GPG_ERR_GENERAL);
+
+  if (listfp)
+    rewind (listfp);
+  while (!(err = read_list (key, country, &lnr)))
+    {
+      if (!strcmp (key, fpr))
+        break;
+    }
+  if (gpg_err_code (err) == GPG_ERR_EOF)
+    err = gpg_error (GPG_ERR_NOT_FOUND);
+
+  xfree (fpr);
+  return err;
+}
+
+
+/* We know that CERT is a qualified certificate.  Ask the user for
+   consent to actually create a signature using this certificate.
+   Returns: 0 for yes, GPG_ERR_CANCEL for no or any otehr error
+   code. */
+gpg_error_t
+gpgsm_qualified_consent (ctrl_t ctrl, ksba_cert_t cert)
+{
+  gpg_error_t err;
+  char *name, *subject, *buffer, *p;
+  const char *s;
+  char *orig_codeset = NULL;
+
+  name = ksba_cert_get_subject (cert, 0);
+  if (!name)
+    return gpg_error (GPG_ERR_GENERAL);
+  subject = gpgsm_format_name2 (name, 0);
+  ksba_free (name); name = NULL;
+
+#ifdef ENABLE_NLS
+  /* The Assuan agent protocol requires us to transmit utf-8 strings */
+  orig_codeset = bind_textdomain_codeset (PACKAGE_GT, NULL);
+#ifdef HAVE_LANGINFO_CODESET
+  if (!orig_codeset)
+    orig_codeset = nl_langinfo (CODESET);
+#endif
+  if (orig_codeset)
+    { /* We only switch when we are able to restore the codeset later.
+         Note that bind_textdomain_codeset does only return on memory
+         errors but not if a codeset is not available.  Thus we don't
+         bother printing a diagnostic here. */
+      orig_codeset = xstrdup (orig_codeset);
+      if (!bind_textdomain_codeset (PACKAGE_GT, "utf-8"))
+        orig_codeset = NULL; 
+    }
+#endif
+
+  if (asprintf (&name,
+                _("You are about to create a signature using your "
+                  "certificate:\n"
+                  "\"%s\"\n"
+                  "This will create a qualified signature by law "
+                  "equated to a handwritten signature.\n\n"
+                  "Are you really sure that you want to do this?"),
+                subject? subject:"?"
+                ) < 0 )
+    err = gpg_error_from_errno (errno);
+  else
+    err = 0;
+
+#ifdef ENABLE_NLS
+  if (orig_codeset)
+    bind_textdomain_codeset (PACKAGE_GT, orig_codeset);
+#endif
+  xfree (orig_codeset);
+  xfree (subject);
+
+  if (err)
+    return err;
+
+  buffer = p = xtrymalloc (strlen (name) * 3 + 1);
+  if (!buffer)
+    {
+      err = gpg_error_from_errno (errno);
+      free (name);
+      return err;
+    }
+  for (s=name; *s; s++)
+    {
+      if (*s < ' ' || *s == '+')
+        {
+          sprintf (p, "%%%02X", *(unsigned char *)s);
+          p += 3;
+        }
+      else if (*s == ' ')
+        *p++ = '+';
+      else
+        *p++ = *s;
+    }
+  *p = 0;
+  free (name); 
+
+
+  err = gpgsm_agent_get_confirmation (ctrl, buffer);
+
+  xfree (buffer);
+  return err;
+}