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/* trustdb.c
* Copyright (c) 1997 by Werner Koch (dd9jn)
*
* This file is part of G10.
*
* G10 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.
*
* G10 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 <unistd.h>
#include <errno.h>
#include <assert.h>
#include "errors.h"
#include "iobuf.h"
#include "keydb.h"
#include "memory.h"
#include "util.h"
#include "trustdb.h"
#include "options.h"
#define TRUST_RECORD_LEN 40
struct trust_record {
byte rectype;
byte reserved;
union {
byte raw[TRUST_RECORD_LEN-2];
struct { /* version record: */
byte magic[2];
byte version; /* should be 1 */
byte reserved[3];
u32 locked; /* pid of process which holds a lock */
u32 created; /* timestamp of trustdb creation */
u32 modified; /* timestamp of last modification */
u32 validated; /* timestamp of last validation */
u32 local_id_counter;
byte marginals_needed;
byte completes_needed;
byte max_cert_depth;
} version;
struct { /* public key record */
u32 local_id;
u32 keyid[2];
byte algo;
byte reserved;
byte fingerprint[20];
byte ownertrust;
} pubkey;
struct { /* cache record */
u32 local_id;
u32 keyid[2];
byte valid;
byte reserved;
byte blockhash[20];
byte n_untrusted;
byte n_marginal;
byte n_fully;
byte trustlevel;
} cache;
} r;
};
static char *db_name;
/**************************************************
************** read and write helpers ************
**************************************************/
static void
fwrite_8(FILE *fp, byte a)
{
if( putc( a & 0xff, fp ) == EOF )
log_fatal("error writing byte to trustdb: %s\n", strerror(errno) );
}
static void
fwrite_16(FILE *fp, u16 a)
{
putc( (a>>8) & 0x0ff , fp );
if( putc( a & 0xff, fp ) == EOF )
log_fatal("error writing u16 to trustdb: %s\n", strerror(errno) );
}
static int
fwrite_32( FILE*fp, u32 a)
{
putc( (a>>24) & 0xff, fp );
putc( (a>>16) & 0xff, fp );
putc( (a>> 8) & 0xff, fp );
if( putc( a & 0xff, fp ) == EOF )
log_fatal("error writing u32 to trustdb: %s\n", strerror(errno) );
}
static int
fwrite_zeros( FILE *fp, size_t n)
{
while( n-- )
if( putc( 0, fp ) == EOF )
log_fatal("error writing zeros to trustdb: %s\n", strerror(errno) );
}
/**************************************************
************** read and write stuff **************
**************************************************/
/****************
* Create a new trustdb
*/
static void
create_db( const char *fname )
{
FILE *fp;
u32 along;
u16 ashort;
fp =fopen( fname, "w" );
if( !fp )
log_fatal("can't create %s: %s\n", fname, strerror(errno) );
fwrite_8( fp, 1 );
fwrite_8( fp, 'g' );
fwrite_8( fp, '1' );
fwrite_8( fp, '0' );
fwrite_8( fp, 1 ); /* version */
fwrite_zeros( fp, 3 ); /* reserved */
fwrite_32( fp, 0 ); /* not locked */
fwrite_32( fp, make_timestamp() ); /* created */
fwrite_32( fp, 0 ); /* not yet modified */
fwrite_32( fp, 0 ); /* not yet validated*/
fwrite_32( fp, 0 ); /* local-id-counter */
fwrite_8( fp, 3 ); /* marginals needed */
fwrite_8( fp, 1 ); /* completes needed */
fwrite_8( fp, 4 ); /* max_cet_depth */
fwrite_zeros( fp, 9 ); /* filler */
fclose(fp);
}
/***********************************************
************* trust logic *******************
***********************************************/
/*********************************************************
**************** API Interface ************************
*********************************************************/
/****************
* Perform some checks over the trustdb
* level 0: used on initial program startup
*/
int
check_trustdb( int level )
{
if( !level ) {
char *fname = make_filename("~/.g10", "trustDB", NULL );
if( access( fname, R_OK ) ) {
if( errno != ENOENT ) {
log_error("can't access %s: %s\n", fname, strerror(errno) );
m_free(fname);
return G10ERR_TRUSTDB;
}
create_db( fname );
}
m_free(db_name);
db_name = fname;
/* we can verify a signature about our local data (secring and trustdb)
* in ~/.g10/ here
*/
}
else
log_bug(NULL);
return 0;
}
/****************
* Get the trustlevel for this PKC.
* Note: This does not ask any questions
* Returns: 0 okay of an errorcode
*
* It operates this way:
* locate the pkc in the trustdb
* found:
* Do we have a valid cache record for it?
* yes: return trustlevel from cache
* no: make a cache record
* not found:
* Return with a trustlevel, saying that we do not have
* a trust record for it. The caller may use insert_trust_record()
* and then call this function here again.
*
* Problems: How do we get the complete keyblock to check that the
* cache record is actually valid? Think we need a clever
* cache in getkey.c to keep track of this stuff. Maybe it
* is not necessary to check this if we use a local pubring. Hmmmm.
*/
int
check_pkc_trust( PKT_public_cert *pkc, int *r_trustlevel )
{
int trustlevel = 0;
if( opt.verbose )
log_info("check_pkc_trust() called.\n");
*r_trustlevel = trustlevel;
return 0;
}
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