started with trust stuff

g10/trustdb.c

@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <errno.h>
 #include <assert.h>
 
@@ -30,6 +31,215 @@
 #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;
+}
+