/* 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 .
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#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
/*
* 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 because
* dotlock does not implement 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 (void)
{
return cache_is_dirty;
}
/*
* Flush the cache. This cannot be used while in a transaction.
*/
int
tdbio_sync (void)
{
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 active.
* 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;
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 (void)
{
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 (void)
{
TRUSTREC rec;
log_assert( db_fd == -1 );
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) );
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 (void)
{
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 (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.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 record 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 *fpr, unsigned int fprlen,
TRUSTREC *rec)
{
int rc;
byte fingerprint[20];
if (fprlen != 20)
{
fpr20_from_fpr (fpr, fprlen, fingerprint);
fpr = fingerprint;
}
/* Locate the trust record using the hash table */
rc = lookup_hashtable (get_trusthashrec (ctrl), fpr, 20,
cmp_trec_fpr, fpr, 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[20];
fpr20_from_pk (pk, fingerprint);
return tdbio_search_trust_byfpr (ctrl, fingerprint, 20, 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);
}