Adding upstream version 2.2.40.upstream/2.2.40upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1936 insertions, 0 deletions

diff --git a/g10/tdbio.c b/g10/tdbio.c
new file mode 100644
index 0000000..fdb8871
--- /dev/null
+++ b/g10/tdbio.c
@@ -0,0 +1,1936 @@
+/* tdbio.c - trust database I/O operations
+ * Copyright (C) 1998-2002, 2012 Free Software Foundation, Inc.
+ * Copyright (C) 1998-2015 Werner Koch
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "gpg.h"
+#include "../common/status.h"
+#include "../common/iobuf.h"
+#include "../common/util.h"
+#include "options.h"
+#include "main.h"
+#include "../common/i18n.h"
+#include "trustdb.h"
+#include "tdbio.h"
+
+#if defined(HAVE_DOSISH_SYSTEM) && !defined(ftruncate)
+#define ftruncate chsize
+#endif
+
+#if defined(HAVE_DOSISH_SYSTEM) || defined(__CYGWIN__)
+#define MY_O_BINARY  O_BINARY
+#else
+#define MY_O_BINARY  0
+#endif
+
+/* We use ERRNO despite that the cegcc provided open/read/write
+   functions don't set ERRNO - at least show that ERRNO does not make
+   sense.  */
+#ifdef HAVE_W32CE_SYSTEM
+#undef strerror
+#define strerror(a) ("[errno not available]")
+#endif
+
+/*
+ * Yes, this is a very simple implementation. We should really
+ * use a page aligned buffer and read complete pages.
+ * To implement a simple trannsaction system, this is sufficient.
+ */
+typedef struct cache_ctrl_struct *CACHE_CTRL;
+struct cache_ctrl_struct
+{
+  CACHE_CTRL next;
+  struct {
+    unsigned used:1;
+    unsigned dirty:1;
+  } flags;
+  ulong recno;
+  char data[TRUST_RECORD_LEN];
+};
+
+/* Size of the cache.  The SOFT value is the general one.  While in a
+   transaction this may not be sufficient and thus we may increase it
+   then up to the HARD limit.  */
+#define MAX_CACHE_ENTRIES_SOFT	200
+#define MAX_CACHE_ENTRIES_HARD	10000
+
+
+/* The cache is controlled by these variables.  */
+static CACHE_CTRL cache_list;
+static int cache_entries;
+static int cache_is_dirty;
+
+
+/* An object to pass information to cmp_krec_fpr. */
+struct cmp_krec_fpr_struct
+{
+  int pubkey_algo;
+  const char *fpr;
+  int fprlen;
+};
+
+/* An object used to pass information to cmp_[s]dir. */
+struct cmp_xdir_struct
+{
+  int pubkey_algo;
+  u32 keyid[2];
+};
+
+
+/* The name of the trustdb file.  */
+static char *db_name;
+
+/* The handle for locking the trustdb file and a counter to record how
+ * often this lock has been taken.  That counter is required becuase
+ * dotlock does not implemen recursive locks.  */
+static dotlock_t lockhandle;
+static unsigned int is_locked;
+
+/* The file descriptor of the trustdb.  */
+static int  db_fd = -1;
+
+/* A flag indicating that a transaction is active.  */
+/* static int in_transaction;   Not yet used. */
+
+
+
+static void open_db (void);
+static void create_hashtable (ctrl_t ctrl, TRUSTREC *vr, int type);
+
+
+
+/*
+ * Take a lock on the trustdb file name.  I a lock file can't be
+ * created the function terminates the process.  Except for a
+ * different return code the function does nothing if the lock has
+ * already been taken.
+ *
+ * Returns: True if lock already exists, False if the lock has
+ *          actually been taken.
+ */
+static int
+take_write_lock (void)
+{
+  int rc;
+
+  if (!lockhandle)
+    lockhandle = dotlock_create (db_name, 0);
+  if (!lockhandle)
+    log_fatal ( _("can't create lock for '%s'\n"), db_name );
+
+  if (!is_locked)
+    {
+      if (dotlock_take (lockhandle, -1) )
+        log_fatal ( _("can't lock '%s'\n"), db_name );
+      rc = 0;
+    }
+  else
+    rc = 1;
+
+  if (opt.lock_once)
+    is_locked = 1;
+  else
+    is_locked++;
+  return rc;
+}
+
+
+/*
+ * Release a lock from the trustdb file unless the global option
+ * --lock-once has been used.
+ */
+static void
+release_write_lock (void)
+{
+  if (opt.lock_once)
+    return;  /* Don't care; here IS_LOCKED is fixed to 1.  */
+
+  if (!is_locked)
+    {
+      log_error ("Ooops, tdbio:release_write_lock with no lock held\n");
+      return;
+    }
+  if (--is_locked)
+    return;
+
+  if (dotlock_release (lockhandle))
+    log_error ("Oops, tdbio:release_write_locked failed\n");
+}
+
+
+
+/*************************************
+ ************* record cache **********
+ *************************************/
+
+/*
+ * Get the data from the record cache and return a pointer into that
+ * cache.  Caller should copy the returned data.  NULL is returned on
+ * a cache miss.
+ */
+static const char *
+get_record_from_cache (ulong recno)
+{
+  CACHE_CTRL r;
+
+  for (r = cache_list; r; r = r->next)
+    {
+      if (r->flags.used && r->recno == recno)
+        return r->data;
+    }
+  return NULL;
+}
+
+
+/*
+ * Write a cached item back to the trustdb file.
+ *
+ * Returns: 0 on success or an error code.
+ */
+static int
+write_cache_item (CACHE_CTRL r)
+{
+  gpg_error_t err;
+  int n;
+
+  if (lseek (db_fd, r->recno * TRUST_RECORD_LEN, SEEK_SET) == -1)
+    {
+      err = gpg_error_from_syserror ();
+      log_error (_("trustdb rec %lu: lseek failed: %s\n"),
+                 r->recno, strerror (errno));
+      return err;
+    }
+  n = write (db_fd, r->data, TRUST_RECORD_LEN);
+  if (n != TRUST_RECORD_LEN)
+    {
+      err = gpg_error_from_syserror ();
+      log_error (_("trustdb rec %lu: write failed (n=%d): %s\n"),
+                 r->recno, n, strerror (errno) );
+      return err;
+    }
+  r->flags.dirty = 0;
+  return 0;
+}
+
+
+/*
+ * Put data into the cache.  This function may flush
+ * some cache entries if the cache is filled up.
+ *
+ * Returns: 0 on success or an error code.
+ */
+static int
+put_record_into_cache (ulong recno, const char *data)
+{
+  CACHE_CTRL r, unused;
+  int dirty_count = 0;
+  int clean_count = 0;
+
+  /* See whether we already cached this one.  */
+  for (unused = NULL, r = cache_list; r; r = r->next)
+    {
+      if (!r->flags.used)
+        {
+          if (!unused)
+            unused = r;
+	}
+      else if (r->recno == recno)
+        {
+          if (!r->flags.dirty)
+            {
+              /* Hmmm: should we use a copy and compare? */
+              if (memcmp (r->data, data, TRUST_RECORD_LEN))
+                {
+                  r->flags.dirty = 1;
+                  cache_is_dirty = 1;
+		}
+	    }
+          memcpy (r->data, data, TRUST_RECORD_LEN);
+          return 0;
+	}
+      if (r->flags.used)
+        {
+          if (r->flags.dirty)
+            dirty_count++;
+          else
+            clean_count++;
+	}
+    }
+
+  /* Not in the cache: add a new entry. */
+  if (unused)
+    {
+      /* Reuse this entry. */
+      r = unused;
+      r->flags.used = 1;
+      r->recno = recno;
+      memcpy (r->data, data, TRUST_RECORD_LEN);
+      r->flags.dirty = 1;
+      cache_is_dirty = 1;
+      cache_entries++;
+      return 0;
+    }
+
+  /* See whether we reached the limit. */
+  if (cache_entries < MAX_CACHE_ENTRIES_SOFT)
+    {
+      /* No: Put into cache.  */
+      r = xmalloc (sizeof *r);
+      r->flags.used = 1;
+      r->recno = recno;
+      memcpy (r->data, data, TRUST_RECORD_LEN);
+      r->flags.dirty = 1;
+      r->next = cache_list;
+      cache_list = r;
+      cache_is_dirty = 1;
+      cache_entries++;
+      return 0;
+    }
+
+  /* Cache is full: discard some clean entries.  */
+  if (clean_count)
+    {
+      int n;
+
+      /* We discard a third of the clean entries.  */
+      n = clean_count / 3;
+      if (!n)
+        n = 1;
+
+      for (unused = NULL, r = cache_list; r; r = r->next)
+        {
+          if (r->flags.used && !r->flags.dirty)
+            {
+              if (!unused)
+                unused = r;
+              r->flags.used = 0;
+              cache_entries--;
+              if (!--n)
+                break;
+	    }
+	}
+
+      /* Now put into the cache.  */
+      log_assert (unused);
+      r = unused;
+      r->flags.used = 1;
+      r->recno = recno;
+      memcpy (r->data, data, TRUST_RECORD_LEN);
+      r->flags.dirty = 1;
+      cache_is_dirty = 1;
+      cache_entries++;
+      return 0;
+    }
+
+  /* No clean entries: We have to flush some dirty entries.  */
+#if 0 /* Transactions are not yet used.  */
+  if (in_transaction)
+    {
+      /* But we can't do this while in a transaction.  Thus we
+       * increase the cache size instead.  */
+      if (cache_entries < MAX_CACHE_ENTRIES_HARD)
+        {
+          if (opt.debug && !(cache_entries % 100))
+            log_debug ("increasing tdbio cache size\n");
+          r = xmalloc (sizeof *r);
+          r->flags.used = 1;
+          r->recno = recno;
+          memcpy (r->data, data, TRUST_RECORD_LEN);
+          r->flags.dirty = 1;
+          r->next = cache_list;
+          cache_list = r;
+          cache_is_dirty = 1;
+          cache_entries++;
+          return 0;
+	}
+      /* Hard limit for the cache size reached.  */
+      log_info (_("trustdb transaction too large\n"));
+      return GPG_ERR_RESOURCE_LIMIT;
+    }
+#endif
+
+  if (dirty_count)
+    {
+      int n;
+
+      /* Discard some dirty entries. */
+      n = dirty_count / 5;
+      if (!n)
+        n = 1;
+
+      take_write_lock ();
+      for (unused = NULL, r = cache_list; r; r = r->next)
+        {
+          if (r->flags.used && r->flags.dirty)
+            {
+              int rc;
+
+              rc = write_cache_item (r);
+              if (rc)
+                return rc;
+              if (!unused)
+                unused = r;
+              r->flags.used = 0;
+              cache_entries--;
+              if (!--n)
+                break;
+	    }
+	}
+      release_write_lock ();
+
+      /* Now put into the cache.  */
+      log_assert (unused);
+      r = unused;
+      r->flags.used = 1;
+      r->recno = recno;
+      memcpy (r->data, data, TRUST_RECORD_LEN);
+      r->flags.dirty = 1;
+      cache_is_dirty = 1;
+      cache_entries++;
+      return 0;
+    }
+
+  /* We should never reach this.  */
+  BUG();
+}
+
+
+/* Return true if the cache is dirty.  */
+int
+tdbio_is_dirty()
+{
+  return cache_is_dirty;
+}
+
+
+/*
+ * Flush the cache.  This cannot be used while in a transaction.
+ */
+int
+tdbio_sync()
+{
+    CACHE_CTRL r;
+    int did_lock = 0;
+
+    if( db_fd == -1 )
+	open_db();
+#if 0 /* Transactions are not yet used.  */
+    if( in_transaction )
+	log_bug("tdbio: syncing while in transaction\n");
+#endif
+
+    if( !cache_is_dirty )
+	return 0;
+
+    if (!take_write_lock ())
+        did_lock = 1;
+
+    for( r = cache_list; r; r = r->next ) {
+	if( r->flags.used && r->flags.dirty ) {
+	    int rc = write_cache_item( r );
+	    if( rc )
+		return rc;
+	}
+    }
+    cache_is_dirty = 0;
+    if (did_lock)
+        release_write_lock ();
+
+    return 0;
+}
+
+
+#if 0  /* Not yet used.  */
+/*
+ * Simple transactions system:
+ * Everything between begin_transaction and end/cancel_transaction
+ * is not immediately written but at the time of end_transaction.
+ *
+ * NOTE: The transaction code is disabled in the 1.2 branch, as it is
+ * not yet used.
+ */
+int
+tdbio_begin_transaction ()  /* Not yet used.  */
+{
+  int rc;
+
+  if (in_transaction)
+    log_bug ("tdbio: nested transactions\n");
+  /* Flush everything out. */
+  rc = tdbio_sync();
+  if (rc)
+    return rc;
+  in_transaction = 1;
+  return 0;
+}
+
+int
+tdbio_end_transaction ()  /* Not yet used.  */
+{
+  int rc;
+
+  if (!in_transaction)
+    log_bug ("tdbio: no active transaction\n");
+  take_write_lock ();
+  gnupg_block_all_signals ();
+  in_transaction = 0;
+  rc = tdbio_sync();
+  gnupg_unblock_all_signals();
+  release_write_lock ();
+  return rc;
+}
+
+int
+tdbio_cancel_transaction () /* Not yet used.  */
+{
+  CACHE_CTRL r;
+
+  if (!in_transaction)
+    log_bug ("tdbio: no active transaction\n");
+
+  /* Remove all dirty marked entries, so that the original ones are
+   * read back the next time.  */
+  if (cache_is_dirty)
+    {
+      for (r = cache_list; r; r = r->next)
+        {
+          if (r->flags.used && r->flags.dirty)
+            {
+              r->flags.used = 0;
+              cache_entries--;
+	    }
+	}
+      cache_is_dirty = 0;
+    }
+
+  in_transaction = 0;
+  return 0;
+}
+#endif  /* Not yet used.  */
+
+
+
+/********************************************************
+ **************** cached I/O functions ******************
+ ********************************************************/
+
+/* The cleanup handler for this module.  */
+static void
+cleanup (void)
+{
+  if (is_locked)
+    {
+      if (!dotlock_release (lockhandle))
+        is_locked = 0;
+    }
+}
+
+
+/*
+ * Update an existing trustdb record.  The caller must call
+ * tdbio_sync.
+ *
+ * Returns: 0 on success or an error code.
+ */
+int
+tdbio_update_version_record (ctrl_t ctrl)
+{
+  TRUSTREC rec;
+  int rc;
+  int opt_tm;
+
+  /* Never store a TOFU trust model in the trustdb.  Use PGP instead.  */
+  opt_tm = opt.trust_model;
+  if (opt_tm == TM_TOFU || opt_tm == TM_TOFU_PGP)
+    opt_tm = TM_PGP;
+
+  memset (&rec, 0, sizeof rec);
+
+  rc = tdbio_read_record (0, &rec, RECTYPE_VER);
+  if (!rc)
+    {
+      rec.r.ver.created     = make_timestamp();
+      rec.r.ver.marginals   = opt.marginals_needed;
+      rec.r.ver.completes   = opt.completes_needed;
+      rec.r.ver.cert_depth  = opt.max_cert_depth;
+      rec.r.ver.trust_model = opt_tm;
+      rec.r.ver.min_cert_level = opt.min_cert_level;
+      rc = tdbio_write_record (ctrl, &rec);
+    }
+
+  return rc;
+}
+
+
+/*
+ * Create and write the trustdb version record.
+ * This is called with the writelock activ.
+ * Returns: 0 on success or an error code.
+ */
+static int
+create_version_record (ctrl_t ctrl)
+{
+  TRUSTREC rec;
+  int rc;
+  int opt_tm;
+
+  /* Never store a TOFU trust model in the trustdb.  Use PGP instead.  */
+  opt_tm = opt.trust_model;
+  if (opt_tm == TM_TOFU || opt_tm == TM_TOFU_PGP)
+    opt_tm = TM_PGP;
+
+  memset (&rec, 0, sizeof rec);
+  rec.r.ver.version     = 3;
+  rec.r.ver.created     = make_timestamp ();
+  rec.r.ver.marginals   = opt.marginals_needed;
+  rec.r.ver.completes   = opt.completes_needed;
+  rec.r.ver.cert_depth  = opt.max_cert_depth;
+  if (opt_tm == TM_PGP || opt_tm == TM_CLASSIC)
+    rec.r.ver.trust_model = opt_tm;
+  else
+    rec.r.ver.trust_model = TM_PGP;
+  rec.r.ver.min_cert_level = opt.min_cert_level;
+  rec.rectype = RECTYPE_VER;
+  rec.recnum = 0;
+  rc = tdbio_write_record (ctrl, &rec);
+
+  if (!rc)
+    tdbio_sync ();
+
+  if (!rc)
+    create_hashtable (ctrl, &rec, 0);
+
+  return rc;
+}
+
+
+/*
+ * Set the file name for the trustdb to NEW_DBNAME and if CREATE is
+ * true create that file.  If NEW_DBNAME is NULL a default name is
+ * used, if the it does not contain a path component separator ('/')
+ * the global GnuPG home directory is used.
+ *
+ * Returns: 0 on success or an error code.
+ *
+ * On the first call this function registers an atexit handler.
+ *
+ */
+int
+tdbio_set_dbname (ctrl_t ctrl, const char *new_dbname,
+                  int create, int *r_nofile)
+{
+  char *fname, *p;
+  struct stat statbuf;
+  static int initialized = 0;
+  int save_slash;
+
+  if (!initialized)
+    {
+      atexit (cleanup);
+      initialized = 1;
+    }
+
+  *r_nofile = 0;
+
+  if (!new_dbname)
+    {
+      fname = make_filename (gnupg_homedir (),
+                             "trustdb" EXTSEP_S GPGEXT_GPG, NULL);
+    }
+  else if (*new_dbname != DIRSEP_C )
+    {
+      if (strchr (new_dbname, DIRSEP_C))
+        fname = make_filename (new_dbname, NULL);
+      else
+        fname = make_filename (gnupg_homedir (), new_dbname, NULL);
+    }
+  else
+    {
+      fname = xstrdup (new_dbname);
+    }
+
+  xfree (db_name);
+  db_name = fname;
+
+  /* Quick check for (likely) case where there already is a
+   * trustdb.gpg.  This check is not required in theory, but it helps
+   * in practice avoiding costly operations of preparing and taking
+   * the lock.  */
+  if (!gnupg_stat (fname, &statbuf) && statbuf.st_size > 0)
+    {
+      /* OK, we have the valid trustdb.gpg already.  */
+      return 0;
+    }
+  else if (!create)
+    {
+      *r_nofile = 1;
+      return 0;
+    }
+
+  /* Here comes: No valid trustdb.gpg AND CREATE==1 */
+
+  /*
+   * Make sure the directory exists.  This should be done before
+   * acquiring the lock, which assumes the existence of the directory.
+   */
+  p = strrchr (fname, DIRSEP_C);
+#if HAVE_W32_SYSTEM
+  {
+    /* Windows may either have a slash or a backslash.  Take
+       care of it.  */
+    char *pp = strrchr (fname, '/');
+    if (!p || pp > p)
+      p = pp;
+  }
+#endif /*HAVE_W32_SYSTEM*/
+  log_assert (p);
+  save_slash = *p;
+  *p = 0;
+  if (gnupg_access (fname, F_OK))
+    {
+      try_make_homedir (fname);
+      if (gnupg_access (fname, F_OK))
+        log_fatal (_("%s: directory does not exist!\n"), fname);
+    }
+  *p = save_slash;
+
+  take_write_lock ();
+
+  if (gnupg_access (fname, R_OK)
+      || gnupg_stat (fname, &statbuf)
+      || statbuf.st_size == 0)
+    {
+      estream_t fp;
+      TRUSTREC rec;
+      int rc;
+      mode_t oldmask;
+
+#ifdef HAVE_W32CE_SYSTEM
+      /* We know how the cegcc implementation of access works ;-). */
+      if (GetLastError () == ERROR_FILE_NOT_FOUND)
+        gpg_err_set_errno (ENOENT);
+      else
+        gpg_err_set_errno (EIO);
+#endif /*HAVE_W32CE_SYSTEM*/
+      if (errno && errno != ENOENT)
+        log_fatal ( _("can't access '%s': %s\n"), fname, strerror (errno));
+
+      oldmask = umask (077);
+      if (is_secured_filename (fname))
+        {
+          fp = NULL;
+          gpg_err_set_errno (EPERM);
+        }
+      else
+        fp = es_fopen (fname, "wb");
+      umask(oldmask);
+      if (!fp)
+        log_fatal (_("can't create '%s': %s\n"), fname, strerror (errno));
+      es_fclose (fp);
+
+      db_fd = gnupg_open (db_name, O_RDWR | MY_O_BINARY, 0);
+      if (db_fd == -1)
+        log_fatal (_("can't open '%s': %s\n"), db_name, strerror (errno));
+
+      rc = create_version_record (ctrl);
+      if (rc)
+        log_fatal (_("%s: failed to create version record: %s"),
+                   fname, gpg_strerror (rc));
+
+      /* Read again to check that we are okay. */
+      if (tdbio_read_record (0, &rec, RECTYPE_VER))
+        log_fatal (_("%s: invalid trustdb created\n"), db_name);
+
+      if (!opt.quiet)
+        log_info (_("%s: trustdb created\n"), db_name);
+    }
+
+  release_write_lock ();
+  return 0;
+}
+
+
+/*
+ * Return the full name of the trustdb.
+ */
+const char *
+tdbio_get_dbname ()
+{
+  return db_name;
+}
+
+
+/*
+ * Open the trustdb.  This may only be called if it has not yet been
+ * opened and after a successful call to tdbio_set_dbname.  On return
+ * the trustdb handle (DB_FD) is guaranteed to be open.
+ */
+static void
+open_db ()
+{
+  TRUSTREC rec;
+
+  log_assert( db_fd == -1 );
+
+#ifdef HAVE_W32CE_SYSTEM
+  {
+    DWORD prevrc = 0;
+    wchar_t *wname = utf8_to_wchar (db_name);
+    if (wname)
+      {
+        db_fd = (int)CreateFile (wname, GENERIC_READ|GENERIC_WRITE,
+                                 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL,
+                                 OPEN_EXISTING, 0, NULL);
+        xfree (wname);
+      }
+    if (db_fd == -1)
+      log_fatal ("can't open '%s': %d, %d\n", db_name,
+                 (int)prevrc, (int)GetLastError ());
+  }
+#else /*!HAVE_W32CE_SYSTEM*/
+  db_fd = gnupg_open (db_name, O_RDWR | MY_O_BINARY, 0);
+  if (db_fd == -1 && (errno == EACCES
+#ifdef EROFS
+                      || errno == EROFS
+#endif
+                      )
+      ) {
+      /* Take care of read-only trustdbs.  */
+      db_fd = gnupg_open (db_name, O_RDONLY | MY_O_BINARY, 0);
+      if (db_fd != -1 && !opt.quiet)
+          log_info (_("Note: trustdb not writable\n"));
+  }
+  if ( db_fd == -1 )
+    log_fatal( _("can't open '%s': %s\n"), db_name, strerror(errno) );
+#endif /*!HAVE_W32CE_SYSTEM*/
+  register_secured_file (db_name);
+
+  /* Read the version record. */
+  if (tdbio_read_record (0, &rec, RECTYPE_VER ) )
+    log_fatal( _("%s: invalid trustdb\n"), db_name );
+}
+
+
+/*
+ * Append a new empty hashtable to the trustdb.  TYPE gives the type
+ * of the hash table.  The only defined type is 0 for a trust hash.
+ * On return the hashtable has been created, written, the version
+ * record update, and the data flushed to the disk.  On a fatal error
+ * the function terminates the process.
+ */
+static void
+create_hashtable (ctrl_t ctrl, TRUSTREC *vr, int type)
+{
+  TRUSTREC rec;
+  off_t offset;
+  ulong recnum;
+  int i, n, rc;
+
+  offset = lseek (db_fd, 0, SEEK_END);
+  if (offset == -1)
+    log_fatal ("trustdb: lseek to end failed: %s\n", strerror(errno));
+  recnum = offset / TRUST_RECORD_LEN;
+  log_assert (recnum); /* This is will never be the first record. */
+
+  if (!type)
+    vr->r.ver.trusthashtbl = recnum;
+
+  /* Now write the records making up the hash table. */
+  n = (256+ITEMS_PER_HTBL_RECORD-1) / ITEMS_PER_HTBL_RECORD;
+  for (i=0; i < n; i++, recnum++)
+    {
+      memset (&rec, 0, sizeof rec);
+      rec.rectype = RECTYPE_HTBL;
+      rec.recnum = recnum;
+      rc = tdbio_write_record (ctrl, &rec);
+      if (rc)
+        log_fatal (_("%s: failed to create hashtable: %s\n"),
+                   db_name, gpg_strerror (rc));
+    }
+  /* Update the version record and flush. */
+  rc = tdbio_write_record (ctrl, vr);
+  if (!rc)
+    rc = tdbio_sync ();
+  if (rc)
+    log_fatal (_("%s: error updating version record: %s\n"),
+               db_name, gpg_strerror (rc));
+}
+
+
+/*
+ * Check whether open trustdb matches the global trust options given
+ * for this process.  On a read problem the process is terminated.
+ *
+ * Return: 1 for yes, 0 for no.
+ */
+int
+tdbio_db_matches_options()
+{
+  static int yes_no = -1;
+
+  if (yes_no == -1)
+    {
+      TRUSTREC vr;
+      int rc;
+      int opt_tm, tm;
+
+      rc = tdbio_read_record (0, &vr, RECTYPE_VER);
+      if( rc )
+	log_fatal( _("%s: error reading version record: %s\n"),
+		   db_name, gpg_strerror (rc) );
+
+      /* Consider tofu and pgp the same.  */
+      tm = vr.r.ver.trust_model;
+      if (tm == TM_TOFU || tm == TM_TOFU_PGP)
+        tm = TM_PGP;
+      opt_tm  = opt.trust_model;
+      if (opt_tm == TM_TOFU || opt_tm == TM_TOFU_PGP)
+        opt_tm = TM_PGP;
+
+      yes_no = vr.r.ver.marginals == opt.marginals_needed
+	&& vr.r.ver.completes == opt.completes_needed
+	&& vr.r.ver.cert_depth == opt.max_cert_depth
+	&& tm == opt_tm
+	&& vr.r.ver.min_cert_level == opt.min_cert_level;
+    }
+
+  return yes_no;
+}
+
+
+/*
+ * Read and return the trust model identifier from the trustdb.  On a
+ * read problem the process is terminated.
+ */
+byte
+tdbio_read_model (void)
+{
+  TRUSTREC vr;
+  int rc;
+
+  rc = tdbio_read_record (0, &vr, RECTYPE_VER );
+  if (rc)
+    log_fatal (_("%s: error reading version record: %s\n"),
+	       db_name, gpg_strerror (rc) );
+  return vr.r.ver.trust_model;
+}
+
+
+/*
+ * Read and return the nextstamp value from the trustdb.  On a read
+ * problem the process is terminated.
+ */
+ulong
+tdbio_read_nextcheck ()
+{
+  TRUSTREC vr;
+  int rc;
+
+  rc = tdbio_read_record (0, &vr, RECTYPE_VER);
+  if (rc)
+    log_fatal (_("%s: error reading version record: %s\n"),
+               db_name, gpg_strerror (rc));
+  return vr.r.ver.nextcheck;
+}
+
+
+/*
+ * Write the STAMP nextstamp timestamp to the trustdb.  On a read or
+ * write problem the process is terminated.
+ *
+ * Return: True if the stamp actually changed.
+ */
+int
+tdbio_write_nextcheck (ctrl_t ctrl, ulong stamp)
+{
+  TRUSTREC vr;
+  int rc;
+
+  rc = tdbio_read_record (0, &vr, RECTYPE_VER);
+  if (rc)
+    log_fatal (_("%s: error reading version record: %s\n"),
+               db_name, gpg_strerror (rc));
+
+  if (vr.r.ver.nextcheck == stamp)
+    return 0;
+
+  vr.r.ver.nextcheck = stamp;
+  rc = tdbio_write_record (ctrl, &vr);
+  if (rc)
+    log_fatal (_("%s: error writing version record: %s\n"),
+               db_name, gpg_strerror (rc));
+  return 1;
+}
+
+
+
+/*
+ * Return the record number of the trusthash table or create one if it
+ * does not yet exist.  On a read or write problem the process is
+ * terminated.
+ *
+ * Return: record number
+ */
+static ulong
+get_trusthashrec (ctrl_t ctrl)
+{
+  static ulong trusthashtbl; /* Record number of the trust hashtable.  */
+
+  (void)ctrl;
+
+  if (!trusthashtbl)
+    {
+      TRUSTREC vr;
+      int rc;
+
+      rc = tdbio_read_record (0, &vr, RECTYPE_VER );
+      if (rc)
+        log_fatal (_("%s: error reading version record: %s\n"),
+                   db_name, gpg_strerror (rc) );
+
+      if (!vr.r.ver.trusthashtbl)
+        {
+          /* Oops: the trustdb is corrupt because the hashtable is
+           * always created along with the version record.  However,
+           * if something went initially wrong it may happen that
+           * there is just the version record.  We try to fix it here.
+           * If we can't do that we return 0 - this is the version
+           * record and thus the actual read will detect the mismatch
+           * and bail out.  Note that create_hashtable updates VR.  */
+          take_write_lock ();
+          if (lseek (db_fd, 0, SEEK_END) == TRUST_RECORD_LEN)
+            create_hashtable (ctrl, &vr, 0);
+          release_write_lock ();
+        }
+      trusthashtbl = vr.r.ver.trusthashtbl;
+    }
+
+  return trusthashtbl;
+}
+
+
+
+/*
+ * Update a hashtable in the trustdb.  TABLE gives the start of the
+ * table, KEY and KEYLEN are the key, NEWRECNUM is the record number
+ * to insert into the table.
+ *
+ * Return: 0 on success or an error code.
+ */
+static int
+upd_hashtable (ctrl_t ctrl, ulong table, byte *key, int keylen, ulong newrecnum)
+{
+  TRUSTREC lastrec, rec;
+  ulong hashrec, item;
+  int msb;
+  int level = 0;
+  int rc, i;
+
+  hashrec = table;
+ next_level:
+  msb = key[level];
+  hashrec += msb / ITEMS_PER_HTBL_RECORD;
+  rc = tdbio_read_record (hashrec, &rec, RECTYPE_HTBL);
+  if (rc)
+    {
+      log_error ("upd_hashtable: read failed: %s\n", gpg_strerror (rc));
+      return rc;
+    }
+
+  item = rec.r.htbl.item[msb % ITEMS_PER_HTBL_RECORD];
+  if (!item)  /* Insert a new item into the hash table.  */
+    {
+      rec.r.htbl.item[msb % ITEMS_PER_HTBL_RECORD] = newrecnum;
+      rc = tdbio_write_record (ctrl, &rec);
+      if (rc)
+        {
+          log_error ("upd_hashtable: write htbl failed: %s\n",
+                     gpg_strerror (rc));
+          return rc;
+	}
+    }
+  else if (item != newrecnum) /* Must do an update.  */
+    {
+      lastrec = rec;
+      rc = tdbio_read_record (item, &rec, 0);
+      if (rc)
+        {
+          log_error ("upd_hashtable: read item failed: %s\n",
+                     gpg_strerror (rc));
+          return rc;
+	}
+
+      if (rec.rectype == RECTYPE_HTBL)
+        {
+          hashrec = item;
+          level++;
+          if (level >= keylen)
+            {
+              log_error ("hashtable has invalid indirections.\n");
+              return GPG_ERR_TRUSTDB;
+	    }
+          goto next_level;
+	}
+      else if (rec.rectype == RECTYPE_HLST) /* Extend the list.  */
+        {
+          /* Check whether the key is already in this list. */
+          for (;;)
+            {
+              for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+                {
+                  if (rec.r.hlst.rnum[i] == newrecnum)
+                    {
+                      return 0; /* Okay, already in the list.  */
+		    }
+		}
+              if (rec.r.hlst.next)
+                {
+                  rc = tdbio_read_record (rec.r.hlst.next, &rec, RECTYPE_HLST);
+                  if (rc)
+                    {
+                      log_error ("upd_hashtable: read hlst failed: %s\n",
+                                 gpg_strerror (rc) );
+                      return rc;
+		    }
+		}
+              else
+                break; /* key is not in the list */
+	    }
+
+          /* Find the next free entry and put it in.  */
+          for (;;)
+            {
+              for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+                {
+                  if (!rec.r.hlst.rnum[i])
+                    {
+                      /* Empty slot found.  */
+                      rec.r.hlst.rnum[i] = newrecnum;
+                      rc = tdbio_write_record (ctrl, &rec);
+                      if (rc)
+                        log_error ("upd_hashtable: write hlst failed: %s\n",
+                                   gpg_strerror (rc));
+                      return rc; /* Done.  */
+		    }
+		}
+
+              if (rec.r.hlst.next)
+                {
+                  /* read the next reord of the list.  */
+                  rc = tdbio_read_record (rec.r.hlst.next, &rec, RECTYPE_HLST);
+                  if (rc)
+                    {
+                      log_error ("upd_hashtable: read hlst failed: %s\n",
+                                 gpg_strerror (rc));
+                      return rc;
+		    }
+		}
+              else
+                {
+                  /* Append a new record to the list.  */
+                  rec.r.hlst.next = item = tdbio_new_recnum (ctrl);
+                  rc = tdbio_write_record (ctrl, &rec);
+                  if (rc)
+                    {
+                      log_error ("upd_hashtable: write hlst failed: %s\n",
+                                 gpg_strerror (rc));
+                      return rc;
+		    }
+                  memset (&rec, 0, sizeof rec);
+                  rec.rectype = RECTYPE_HLST;
+                  rec.recnum = item;
+                  rec.r.hlst.rnum[0] = newrecnum;
+                  rc = tdbio_write_record (ctrl, &rec);
+                  if (rc)
+                    log_error ("upd_hashtable: write ext hlst failed: %s\n",
+                               gpg_strerror (rc));
+                  return rc; /* Done.  */
+		}
+	    } /* end loop over list slots */
+
+	}
+      else if (rec.rectype == RECTYPE_TRUST) /* Insert a list record.  */
+        {
+          if (rec.recnum == newrecnum)
+            {
+              return 0;
+            }
+          item = rec.recnum; /* Save number of key record.  */
+          memset (&rec, 0, sizeof rec);
+          rec.rectype = RECTYPE_HLST;
+          rec.recnum = tdbio_new_recnum (ctrl);
+          rec.r.hlst.rnum[0] = item;	    /* Old key record */
+          rec.r.hlst.rnum[1] = newrecnum; /* and new key record */
+          rc = tdbio_write_record (ctrl, &rec);
+          if (rc)
+            {
+              log_error( "upd_hashtable: write new hlst failed: %s\n",
+                           gpg_strerror (rc) );
+              return rc;
+            }
+          /* Update the hashtable record.  */
+          lastrec.r.htbl.item[msb % ITEMS_PER_HTBL_RECORD] = rec.recnum;
+          rc = tdbio_write_record (ctrl, &lastrec);
+          if (rc)
+            log_error ("upd_hashtable: update htbl failed: %s\n",
+                       gpg_strerror (rc));
+          return rc; /* Ready.  */
+        }
+      else
+        {
+          log_error ("hashtbl %lu: %lu/%d points to an invalid record %lu\n",
+                     table, hashrec, (msb % ITEMS_PER_HTBL_RECORD), item);
+          if (opt.verbose > 1)
+            list_trustdb (ctrl, es_stderr, NULL);
+          return GPG_ERR_TRUSTDB;
+	}
+    }
+
+  return 0;
+}
+
+
+/*
+ * Drop an entry from a hashtable.  TABLE gives the start of the
+ * table, KEY and KEYLEN are the key.
+ *
+ * Return: 0 on success or an error code.
+ */
+static int
+drop_from_hashtable (ctrl_t ctrl, ulong table,
+                     byte *key, int keylen, ulong recnum)
+{
+  TRUSTREC rec;
+  ulong hashrec, item;
+  int msb;
+  int level = 0;
+  int rc, i;
+
+  hashrec = table;
+ next_level:
+  msb = key[level];
+  hashrec += msb / ITEMS_PER_HTBL_RECORD;
+  rc = tdbio_read_record (hashrec, &rec, RECTYPE_HTBL );
+  if (rc)
+    {
+      log_error ("drop_from_hashtable: read failed: %s\n", gpg_strerror (rc));
+      return rc;
+    }
+
+  item = rec.r.htbl.item[msb % ITEMS_PER_HTBL_RECORD];
+  if (!item)
+    return 0;   /* Not found - forget about it.  */
+
+  if (item == recnum) /* Table points direct to the record.  */
+    {
+      rec.r.htbl.item[msb % ITEMS_PER_HTBL_RECORD] = 0;
+      rc = tdbio_write_record (ctrl, &rec);
+      if (rc)
+        log_error ("drop_from_hashtable: write htbl failed: %s\n",
+                   gpg_strerror (rc));
+      return rc;
+    }
+
+  rc = tdbio_read_record (item, &rec, 0);
+  if (rc)
+    {
+      log_error ("drop_from_hashtable: read item failed: %s\n",
+                 gpg_strerror (rc));
+      return rc;
+    }
+
+  if (rec.rectype == RECTYPE_HTBL)
+    {
+      hashrec = item;
+      level++;
+      if (level >= keylen)
+        {
+          log_error ("hashtable has invalid indirections.\n");
+          return GPG_ERR_TRUSTDB;
+	}
+      goto next_level;
+    }
+
+  if (rec.rectype == RECTYPE_HLST)
+    {
+      for (;;)
+        {
+          for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+            {
+              if (rec.r.hlst.rnum[i] == recnum)
+                {
+                  rec.r.hlst.rnum[i] = 0; /* Mark as free.  */
+                  rc = tdbio_write_record (ctrl, &rec);
+                  if (rc)
+                    log_error("drop_from_hashtable: write htbl failed: %s\n",
+                              gpg_strerror (rc));
+                  return rc;
+		}
+	    }
+          if (rec.r.hlst.next)
+            {
+              rc = tdbio_read_record (rec.r.hlst.next, &rec, RECTYPE_HLST);
+              if (rc)
+                {
+                  log_error ("drop_from_hashtable: read hlst failed: %s\n",
+                             gpg_strerror (rc));
+                  return rc;
+		}
+	    }
+          else
+            return 0; /* Key not in table.  */
+	}
+    }
+
+  log_error ("hashtbl %lu: %lu/%d points to wrong record %lu\n",
+             table, hashrec, (msb % ITEMS_PER_HTBL_RECORD), item);
+  return GPG_ERR_TRUSTDB;
+}
+
+
+
+/*
+ * Lookup a record via the hashtable TABLE by (KEY,KEYLEN) and return
+ * the result in REC.  The return value of CMP() should be True if the
+ * record is the desired one.
+ *
+ * Return: 0 if found, GPG_ERR_NOT_FOUND, or another error code.
+ */
+static gpg_error_t
+lookup_hashtable (ulong table, const byte *key, size_t keylen,
+		  int (*cmpfnc)(const void*, const TRUSTREC *),
+                  const void *cmpdata, TRUSTREC *rec )
+{
+  int rc;
+  ulong hashrec, item;
+  int msb;
+  int level = 0;
+
+  if (!table)
+    {
+      rc = gpg_error (GPG_ERR_INV_RECORD);
+      log_error("lookup_hashtable failed: %s\n", "request for record 0");
+      return rc;
+    }
+
+  hashrec = table;
+ next_level:
+  msb = key[level];
+  hashrec += msb / ITEMS_PER_HTBL_RECORD;
+  rc = tdbio_read_record (hashrec, rec, RECTYPE_HTBL);
+  if (rc)
+    {
+      log_error("lookup_hashtable failed: %s\n", gpg_strerror (rc) );
+      return rc;
+    }
+
+  item = rec->r.htbl.item[msb % ITEMS_PER_HTBL_RECORD];
+  if (!item)
+    return gpg_error (GPG_ERR_NOT_FOUND);
+
+  rc = tdbio_read_record (item, rec, 0);
+  if (rc)
+    {
+      log_error( "hashtable read failed: %s\n", gpg_strerror (rc) );
+      return rc;
+    }
+  if (rec->rectype == RECTYPE_HTBL)
+    {
+      hashrec = item;
+      level++;
+      if (level >= keylen)
+        {
+          log_error ("hashtable has invalid indirections\n");
+          return GPG_ERR_TRUSTDB;
+	}
+      goto next_level;
+    }
+  else if (rec->rectype == RECTYPE_HLST)
+    {
+      for (;;)
+        {
+          int i;
+
+          for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+            {
+              if (rec->r.hlst.rnum[i])
+                {
+                  TRUSTREC tmp;
+
+                  rc = tdbio_read_record (rec->r.hlst.rnum[i], &tmp, 0);
+                  if (rc)
+                    {
+                      log_error ("lookup_hashtable: read item failed: %s\n",
+                                 gpg_strerror (rc));
+                      return rc;
+		    }
+                  if ((*cmpfnc)(cmpdata, &tmp))
+                    {
+                      *rec = tmp;
+                      return 0;
+		    }
+		}
+	    }
+          if (rec->r.hlst.next)
+            {
+              rc = tdbio_read_record (rec->r.hlst.next, rec, RECTYPE_HLST);
+              if (rc)
+                {
+                  log_error ("lookup_hashtable: read hlst failed: %s\n",
+                             gpg_strerror (rc) );
+                  return rc;
+		}
+	    }
+          else
+            return gpg_error (GPG_ERR_NOT_FOUND);
+	}
+    }
+
+  if ((*cmpfnc)(cmpdata, rec))
+    return 0; /* really found */
+
+  return gpg_error (GPG_ERR_NOT_FOUND); /* no: not found */
+}
+
+
+/*
+ * Update the trust hash table TR or create the table if it does not
+ * exist.
+ *
+ * Return: 0 on success or an error code.
+ */
+static int
+update_trusthashtbl (ctrl_t ctrl, TRUSTREC *tr)
+{
+  return upd_hashtable (ctrl, get_trusthashrec (ctrl),
+                        tr->r.trust.fingerprint, 20, tr->recnum);
+}
+
+
+/*
+ * Dump the trustdb record REC to stream FP.
+ */
+void
+tdbio_dump_record (TRUSTREC *rec, estream_t fp)
+{
+  int i;
+  ulong rnum = rec->recnum;
+
+  es_fprintf (fp, "rec %5lu, ", rnum);
+
+  switch (rec->rectype)
+    {
+    case 0:
+      es_fprintf (fp, "blank\n");
+      break;
+
+    case RECTYPE_VER:
+      es_fprintf (fp,
+         "version, td=%lu, f=%lu, m/c/d=%d/%d/%d tm=%d mcl=%d nc=%lu (%s)\n",
+                  rec->r.ver.trusthashtbl,
+                  rec->r.ver.firstfree,
+                  rec->r.ver.marginals,
+                  rec->r.ver.completes,
+                  rec->r.ver.cert_depth,
+                  rec->r.ver.trust_model,
+                  rec->r.ver.min_cert_level,
+                  rec->r.ver.nextcheck,
+                  strtimestamp(rec->r.ver.nextcheck)
+                  );
+      break;
+
+    case RECTYPE_FREE:
+      es_fprintf (fp, "free, next=%lu\n", rec->r.free.next);
+      break;
+
+    case RECTYPE_HTBL:
+      es_fprintf (fp, "htbl,");
+      for (i=0; i < ITEMS_PER_HTBL_RECORD; i++)
+        es_fprintf (fp, " %lu", rec->r.htbl.item[i]);
+      es_putc ('\n', fp);
+      break;
+
+    case RECTYPE_HLST:
+      es_fprintf (fp, "hlst, next=%lu,", rec->r.hlst.next);
+      for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+        es_fprintf (fp, " %lu", rec->r.hlst.rnum[i]);
+      es_putc ('\n', fp);
+      break;
+
+    case RECTYPE_TRUST:
+      es_fprintf (fp, "trust ");
+      for (i=0; i < 20; i++)
+        es_fprintf (fp, "%02X", rec->r.trust.fingerprint[i]);
+      es_fprintf (fp, ", ot=%d, d=%d, vl=%lu, mo=%d, f=%02x\n",
+                  rec->r.trust.ownertrust,
+                  rec->r.trust.depth, rec->r.trust.validlist,
+                  rec->r.trust.min_ownertrust, rec->r.trust.flags);
+      break;
+
+    case RECTYPE_VALID:
+      es_fprintf (fp, "valid ");
+      for (i=0; i < 20; i++)
+        es_fprintf(fp, "%02X", rec->r.valid.namehash[i]);
+      es_fprintf (fp, ", v=%d, next=%lu, f=%d, m=%d\n",
+                  rec->r.valid.validity, rec->r.valid.next,
+                  rec->r.valid.full_count, rec->r.valid.marginal_count);
+      break;
+
+    default:
+      es_fprintf (fp, "unknown type %d\n", rec->rectype );
+      break;
+    }
+}
+
+
+/*
+ * Read the record with number RECNUM into the structure REC.  If
+ * EXPECTED is not 0 reading any other record type will return an
+ * error.
+ *
+ * Return: 0 on success or an error code.
+ */
+int
+tdbio_read_record (ulong recnum, TRUSTREC *rec, int expected)
+{
+  byte readbuf[TRUST_RECORD_LEN];
+  const byte *buf, *p;
+  gpg_error_t err = 0;
+  int n, i;
+
+  if (db_fd == -1)
+    open_db ();
+
+  buf = get_record_from_cache( recnum );
+  if (!buf)
+    {
+      if (lseek (db_fd, recnum * TRUST_RECORD_LEN, SEEK_SET) == -1)
+        {
+          err = gpg_error_from_syserror ();
+          log_error (_("trustdb: lseek failed: %s\n"), strerror (errno));
+          return err;
+	}
+      n = read (db_fd, readbuf, TRUST_RECORD_LEN);
+      if (!n)
+        {
+          return gpg_error (GPG_ERR_EOF);
+	}
+      else if (n != TRUST_RECORD_LEN)
+        {
+          err = gpg_error_from_syserror ();
+          log_error (_("trustdb: read failed (n=%d): %s\n"),
+                     n, strerror(errno));
+          return err;
+	}
+      buf = readbuf;
+    }
+  rec->recnum = recnum;
+  rec->dirty = 0;
+  p = buf;
+  rec->rectype = *p++;
+  if (expected && rec->rectype != expected)
+    {
+      log_error ("%lu: read expected rec type %d, got %d\n",
+                 recnum, expected, rec->rectype);
+      return gpg_error (GPG_ERR_TRUSTDB);
+    }
+  p++;    /* Skip reserved byte.  */
+  switch (rec->rectype)
+    {
+    case 0:  /* unused (free) record */
+      break;
+
+    case RECTYPE_VER: /* version record */
+      if (memcmp(buf+1, GPGEXT_GPG, 3))
+        {
+          log_error (_("%s: not a trustdb file\n"), db_name );
+          err = gpg_error (GPG_ERR_TRUSTDB);
+        }
+      else
+        {
+          p += 2; /* skip "gpg" */
+          rec->r.ver.version  = *p++;
+          rec->r.ver.marginals = *p++;
+          rec->r.ver.completes = *p++;
+          rec->r.ver.cert_depth = *p++;
+          rec->r.ver.trust_model = *p++;
+          rec->r.ver.min_cert_level = *p++;
+          p += 2;
+          rec->r.ver.created  = buf32_to_ulong(p);
+          p += 4;
+          rec->r.ver.nextcheck = buf32_to_ulong(p);
+          p += 4;
+          p += 4;
+          p += 4;
+          rec->r.ver.firstfree = buf32_to_ulong(p);
+          p += 4;
+          p += 4;
+          rec->r.ver.trusthashtbl = buf32_to_ulong(p);
+          if (recnum)
+            {
+              log_error( _("%s: version record with recnum %lu\n"), db_name,
+                         (ulong)recnum );
+              err = gpg_error (GPG_ERR_TRUSTDB);
+            }
+          else if (rec->r.ver.version != 3)
+            {
+              log_error( _("%s: invalid file version %d\n"), db_name,
+                         rec->r.ver.version );
+              err = gpg_error (GPG_ERR_TRUSTDB);
+            }
+        }
+      break;
+
+    case RECTYPE_FREE:
+      rec->r.free.next  = buf32_to_ulong(p);
+      break;
+
+    case RECTYPE_HTBL:
+      for (i=0; i < ITEMS_PER_HTBL_RECORD; i++)
+        {
+          rec->r.htbl.item[i] = buf32_to_ulong(p);
+          p += 4;
+	}
+      break;
+
+    case RECTYPE_HLST:
+      rec->r.hlst.next = buf32_to_ulong(p);
+      p += 4;
+      for (i=0; i < ITEMS_PER_HLST_RECORD; i++)
+        {
+          rec->r.hlst.rnum[i] = buf32_to_ulong(p);
+          p += 4;
+	}
+      break;
+
+    case RECTYPE_TRUST:
+      memcpy (rec->r.trust.fingerprint, p, 20);
+      p+=20;
+      rec->r.trust.ownertrust = *p++;
+      rec->r.trust.depth = *p++;
+      rec->r.trust.min_ownertrust = *p++;
+      rec->r.trust.flags = *p++;
+      rec->r.trust.validlist = buf32_to_ulong(p);
+      break;
+
+    case RECTYPE_VALID:
+      memcpy (rec->r.valid.namehash, p, 20);
+      p+=20;
+      rec->r.valid.validity = *p++;
+      rec->r.valid.next = buf32_to_ulong(p);
+      p += 4;
+      rec->r.valid.full_count = *p++;
+      rec->r.valid.marginal_count = *p++;
+      break;
+
+    default:
+      log_error ("%s: invalid record type %d at recnum %lu\n",
+                 db_name, rec->rectype, (ulong)recnum);
+      err = gpg_error (GPG_ERR_TRUSTDB);
+      break;
+    }
+
+  return err;
+}
+
+
+/*
+ * Write the record from the struct REC.
+ *
+ * Return: 0 on success or an error code.
+ */
+int
+tdbio_write_record (ctrl_t ctrl, TRUSTREC *rec)
+{
+  byte buf[TRUST_RECORD_LEN];
+  byte *p;
+  int rc = 0;
+  int i;
+  ulong recnum = rec->recnum;
+
+  if (db_fd == -1)
+    open_db ();
+
+  memset (buf, 0, TRUST_RECORD_LEN);
+  p = buf;
+  *p++ = rec->rectype; p++;
+
+  switch (rec->rectype)
+    {
+    case 0:  /* unused record */
+      break;
+
+    case RECTYPE_VER: /* version record */
+      if (recnum)
+        BUG ();
+      memcpy(p-1, GPGEXT_GPG, 3 ); p += 2;
+      *p++ = rec->r.ver.version;
+      *p++ = rec->r.ver.marginals;
+      *p++ = rec->r.ver.completes;
+      *p++ = rec->r.ver.cert_depth;
+      *p++ = rec->r.ver.trust_model;
+      *p++ = rec->r.ver.min_cert_level;
+      p += 2;
+      ulongtobuf(p, rec->r.ver.created); p += 4;
+      ulongtobuf(p, rec->r.ver.nextcheck); p += 4;
+      p += 4;
+      p += 4;
+      ulongtobuf(p, rec->r.ver.firstfree ); p += 4;
+      p += 4;
+      ulongtobuf(p, rec->r.ver.trusthashtbl ); p += 4;
+      break;
+
+    case RECTYPE_FREE:
+      ulongtobuf(p, rec->r.free.next); p += 4;
+      break;
+
+    case RECTYPE_HTBL:
+      for (i=0; i < ITEMS_PER_HTBL_RECORD; i++)
+        {
+          ulongtobuf( p, rec->r.htbl.item[i]); p += 4;
+        }
+      break;
+
+    case RECTYPE_HLST:
+      ulongtobuf( p, rec->r.hlst.next); p += 4;
+      for (i=0; i < ITEMS_PER_HLST_RECORD; i++ )
+        {
+          ulongtobuf( p, rec->r.hlst.rnum[i]); p += 4;
+	}
+      break;
+
+    case RECTYPE_TRUST:
+      memcpy (p, rec->r.trust.fingerprint, 20); p += 20;
+      *p++ = rec->r.trust.ownertrust;
+      *p++ = rec->r.trust.depth;
+      *p++ = rec->r.trust.min_ownertrust;
+      *p++ = rec->r.trust.flags;
+      ulongtobuf( p, rec->r.trust.validlist); p += 4;
+      break;
+
+    case RECTYPE_VALID:
+      memcpy (p, rec->r.valid.namehash, 20); p += 20;
+      *p++ = rec->r.valid.validity;
+      ulongtobuf( p, rec->r.valid.next); p += 4;
+      *p++ = rec->r.valid.full_count;
+      *p++ = rec->r.valid.marginal_count;
+      break;
+
+    default:
+      BUG();
+    }
+
+  rc = put_record_into_cache (recnum, buf);
+  if (rc)
+    ;
+  else if (rec->rectype == RECTYPE_TRUST)
+    rc = update_trusthashtbl (ctrl, rec);
+
+  return rc;
+}
+
+
+/*
+ * Delete the record at record number RECNUm from the trustdb.
+ *
+ * Return: 0 on success or an error code.
+ */
+int
+tdbio_delete_record (ctrl_t ctrl, ulong recnum)
+{
+  TRUSTREC vr, rec;
+  int rc;
+
+  /* Must read the record fist, so we can drop it from the hash tables */
+  rc = tdbio_read_record (recnum, &rec, 0);
+  if (rc)
+    ;
+  else if (rec.rectype == RECTYPE_TRUST)
+    {
+      rc = drop_from_hashtable (ctrl, get_trusthashrec (ctrl),
+                                rec.r.trust.fingerprint, 20, rec.recnum);
+    }
+
+  if (rc)
+    return rc;
+
+  /* Now we can change it to a free record.  */
+  rc = tdbio_read_record (0, &vr, RECTYPE_VER);
+  if (rc)
+    log_fatal (_("%s: error reading version record: %s\n"),
+               db_name, gpg_strerror (rc));
+
+  rec.recnum = recnum;
+  rec.rectype = RECTYPE_FREE;
+  rec.r.free.next = vr.r.ver.firstfree;
+  vr.r.ver.firstfree = recnum;
+  rc = tdbio_write_record (ctrl, &rec);
+  if (!rc)
+    rc = tdbio_write_record (ctrl, &vr);
+
+  return rc;
+}
+
+
+/*
+ * Create a new record and return its record number.
+ */
+ulong
+tdbio_new_recnum (ctrl_t ctrl)
+{
+  off_t offset;
+  ulong recnum;
+  TRUSTREC vr, rec;
+  int rc;
+
+  /* Look for unused records.  */
+  rc = tdbio_read_record (0, &vr, RECTYPE_VER);
+  if (rc)
+    log_fatal( _("%s: error reading version record: %s\n"),
+               db_name, gpg_strerror (rc));
+  if (vr.r.ver.firstfree)
+    {
+      recnum = vr.r.ver.firstfree;
+      rc = tdbio_read_record (recnum, &rec, RECTYPE_FREE);
+      if (rc)
+        log_fatal (_("%s: error reading free record: %s\n"),
+                   db_name, gpg_strerror (rc));
+      /* Update dir record.  */
+      vr.r.ver.firstfree = rec.r.free.next;
+      rc = tdbio_write_record (ctrl, &vr);
+      if (rc)
+        log_fatal (_("%s: error writing dir record: %s\n"),
+                   db_name, gpg_strerror (rc));
+      /* Zero out the new record.  */
+      memset (&rec, 0, sizeof rec);
+      rec.rectype = 0; /* Mark as unused record (actually already done
+                          my the memset).  */
+      rec.recnum = recnum;
+      rc = tdbio_write_record (ctrl, &rec);
+      if (rc)
+        log_fatal (_("%s: failed to zero a record: %s\n"),
+                   db_name, gpg_strerror (rc));
+    }
+  else /* Not found - append a new record.  */
+    {
+      offset = lseek (db_fd, 0, SEEK_END);
+      if (offset == (off_t)(-1))
+        log_fatal ("trustdb: lseek to end failed: %s\n", strerror (errno));
+      recnum = offset / TRUST_RECORD_LEN;
+      log_assert (recnum); /* This will never be the first record */
+      /* We must write a record, so that the next call to this
+       * function returns another recnum.  */
+      memset (&rec, 0, sizeof rec);
+      rec.rectype = 0; /* unused record */
+      rec.recnum = recnum;
+      rc = 0;
+      if (lseek( db_fd, recnum * TRUST_RECORD_LEN, SEEK_SET) == -1)
+        {
+          rc = gpg_error_from_syserror ();
+          log_error (_("trustdb rec %lu: lseek failed: %s\n"),
+                     recnum, strerror (errno));
+	}
+      else
+        {
+          int n;
+
+          n = write (db_fd, &rec, TRUST_RECORD_LEN);
+          if (n != TRUST_RECORD_LEN)
+            {
+              rc = gpg_error_from_syserror ();
+              log_error (_("trustdb rec %lu: write failed (n=%d): %s\n"),
+                         recnum, n, gpg_strerror (rc));
+	    }
+	}
+
+      if (rc)
+        log_fatal (_("%s: failed to append a record: %s\n"),
+                   db_name, gpg_strerror (rc));
+    }
+
+  return recnum ;
+}
+
+
+
+/* Helper function for tdbio_search_trust_byfpr.  */
+static int
+cmp_trec_fpr ( const void *fpr, const TRUSTREC *rec )
+{
+  return (rec->rectype == RECTYPE_TRUST
+          && !memcmp (rec->r.trust.fingerprint, fpr, 20));
+}
+
+
+/*
+ * Given a 20 byte FINGERPRINT search its trust record and return
+ * that at REC.
+ *
+ * Return: 0 if found, GPG_ERR_NOT_FOUND, or another error code.
+ */
+gpg_error_t
+tdbio_search_trust_byfpr (ctrl_t ctrl, const byte *fingerprint, TRUSTREC *rec)
+{
+  int rc;
+
+  /* Locate the trust record using the hash table */
+  rc = lookup_hashtable (get_trusthashrec (ctrl), fingerprint, 20,
+                         cmp_trec_fpr, fingerprint, rec );
+  return rc;
+}
+
+
+/*
+ * Given a primary public key object PK search its trust record and
+ * return that at REC.
+ *
+ * Return: 0 if found, GPG_ERR_NOT_FOUND, or another error code.
+ */
+gpg_error_t
+tdbio_search_trust_bypk (ctrl_t ctrl, PKT_public_key *pk, TRUSTREC *rec)
+{
+  byte fingerprint[MAX_FINGERPRINT_LEN];
+  size_t fingerlen;
+
+  fingerprint_from_pk( pk, fingerprint, &fingerlen );
+  for (; fingerlen < 20; fingerlen++)
+    fingerprint[fingerlen] = 0;
+  return tdbio_search_trust_byfpr (ctrl, fingerprint, rec);
+}
+
+
+/*
+ * Terminate the process with a message about a corrupted trustdb.
+ */
+void
+tdbio_invalid (void)
+{
+  log_error (_("Error: The trustdb is corrupted.\n"));
+  how_to_fix_the_trustdb ();
+  g10_exit (2);
+}