/* 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 #include #include #include #include #include #include #include #include "errors.h" #include "iobuf.h" #include "keydb.h" #include "memory.h" #include "util.h" #include "trustdb.h" #include "options.h" #include "packet.h" #include "main.h" #define TRUST_RECORD_LEN 40 #define SIGS_PER_RECORD ((TRUST_RECORD_LEN-10)/5) #define MAX_LIST_SIGS_DEPTH 20 struct trust_record { byte rectype; byte reserved; union { struct { /* version record: */ byte magic[2]; byte version; /* should be 1 */ byte reserved[3]; ulong locked; /* pid of process which holds a lock */ ulong created; /* timestamp of trustdb creation */ ulong modified; /* timestamp of last modification */ ulong validated; /* timestamp of last validation */ ulong local_id_counter; byte marginals_needed; byte completes_needed; byte max_cert_depth; } version; struct { /* public key record */ ulong local_id; u32 keyid[2]; byte pubkey_algo; byte reserved; byte fingerprint[20]; byte ownertrust; /* fixme: indicate a flag to */ } pubkey; struct { /* cache record */ ulong owner; u32 keyid[2]; /* needed?? */ byte valid; byte reserved; byte blockhash[20]; byte n_untrusted; byte n_marginal; byte n_fully; byte trustlevel; } cache; struct { ulong owner; /* local_id of record owner (pubkey record) */ ulong chain; /* offset of next record or NULL for last one */ struct { ulong local_id; /* of pubkey record of signator (0=unused) */ byte flag; /* reserved */ } sig[SIGS_PER_RECORD]; } sigrec; } r; }; typedef struct trust_record TRUSTREC; typedef struct { ulong pubkey_id; /* localid of the pubkey */ ulong sig_id; /* returned signature id */ unsigned sig_flag; /* returned signaure record flag */ struct { /* internal data */ int eof; TRUSTREC rec; int index; } ctl; } SIGREC_CONTEXT; typedef struct local_id_info *LOCAL_ID_INFO; struct local_id_info { LOCAL_ID_INFO next; ulong lid; unsigned flag; }; static void create_db( const char *fname ); static void open_db(void); static int read_record( ulong recnum, TRUSTREC *rec ); static int write_record( ulong recnum, TRUSTREC *rec ); static ulong new_recnum(void); static void dump_record( ulong rnum, TRUSTREC *rec, FILE *fp ); static int walk_sigrecs( SIGREC_CONTEXT *c ); static LOCAL_ID_INFO *new_lid_table(void); static void release_lid_table( LOCAL_ID_INFO *tbl ); static int get_lid_table_flag( LOCAL_ID_INFO *tbl, ulong lid, unsigned *flag ); static void print_user_id( const char *text, u32 *keyid ); static int do_list_path( ulong pubkey, int depth, int max_depth, LOCAL_ID_INFO *lids, ulong *stack ); static int list_sigs( ulong pubkey_id ); static char *db_name; static int db_fd = -1; static int no_io_dbg = 0; /* a table used to keep track of ultimately trusted keys * which are the ones from our secrings */ static LOCAL_ID_INFO *ultikey_table; #define buftoulong( p ) ((*(byte*)(p) << 24) | (*((byte*)(p)+1)<< 16) | \ (*((byte*)(p)+2) << 8) | (*((byte*)(p)+3))) #define buftoushort( p ) ((*((byte*)(p)) << 8) | (*((byte*)(p)+1))) #define ulongtobuf( p, a ) do { \ ((byte*)p)[0] = a >> 24; \ ((byte*)p)[1] = a >> 16; \ ((byte*)p)[2] = a >> 8; \ ((byte*)p)[3] = a ; \ } while(0) #define ushorttobuf( p, a ) do { \ ((byte*)p)[0] = a >> 8; \ ((byte*)p)[1] = a ; \ } while(0) #define buftou32( p) buftoulong( (p) ) #define u32tobuf( p, a) ulongtobuf( (p), (a) ) /************************************************** ************** 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_32( FILE*fp, ulong 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 ulong to trustdb: %s\n", strerror(errno) ); } static void 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; 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 (not used) */ 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); } static void open_db() { TRUSTREC rec; assert( db_fd == -1 ); db_fd = open( db_name, O_RDWR ); if( db_fd == -1 ) log_fatal("can't open %s: %s\n", db_name, strerror(errno) ); if( read_record( 0, &rec ) ) log_fatal("TrustDB %s is invalid\n", db_name ); /* fixme: check ->locked and other stuff */ } /**************** * read the record with number recnum * returns: -1 on error, 0 on success */ static int read_record( ulong recnum, TRUSTREC *rec ) { byte buf[TRUST_RECORD_LEN], *p; int rc = 0; int n, i; if( db_fd == -1 ) open_db(); if( DBG_TRUST && !no_io_dbg ) log_debug("trustdb: read_record(%lu)\n", (ulong)recnum); if( lseek( db_fd, recnum * TRUST_RECORD_LEN, SEEK_SET ) == -1 ) { log_error("trustdb: lseek failed: %s\n", strerror(errno) ); return G10ERR_READ_FILE; } n = read( db_fd, buf, TRUST_RECORD_LEN); if( !n ) { if( DBG_TRUST ) log_debug("trustdb: no record at %lu\n", (ulong)recnum ); return -1; /* eof */ } else if( n != TRUST_RECORD_LEN ) { log_error("trustdb: read failed (n=%d): %s\n", n, strerror(errno) ); return G10ERR_READ_FILE; } p = buf; rec->rectype = *p++; rec->reserved = *p++; switch( rec->rectype ) { case 0: /* unused record */ break; case 1: /* version record */ rec->r.version.magic[0] = *p++; rec->r.version.magic[1] = *p++; rec->r.version.version = *p++; memcpy( rec->r.version.reserved, p, 3); p += 3; rec->r.version.locked = buftoulong(p); p += 4; rec->r.version.created = buftoulong(p); p += 4; rec->r.version.modified = buftoulong(p); p += 4; rec->r.version.validated= buftoulong(p); p += 4; rec->r.version.local_id_counter = buftoulong(p); p += 4; rec->r.version.marginals_needed = *p++; rec->r.version.completes_needed = *p++; rec->r.version.max_cert_depth = *p++; if( recnum ) { log_error("%s: version record with recnum %lu\n", db_name, (ulong)recnum ); rc = G10ERR_TRUSTDB; } if( rec->reserved != 'g' || rec->r.version.magic[0] != '1' || rec->r.version.magic[1] != '0' ) { log_error("%s: not a trustdb file\n", db_name ); rc = G10ERR_TRUSTDB; } if( rec->r.version.version != 1 ) { log_error("%s: invalid file version %d\n", db_name, rec->r.version.version ); rc = G10ERR_TRUSTDB; } break; case 2: rec->r.pubkey.local_id = buftoulong(p); p += 4; rec->r.pubkey.keyid[0] = buftou32(p); p += 4; rec->r.pubkey.keyid[1] = buftou32(p); p += 4; rec->r.pubkey.pubkey_algo = *p++; rec->r.pubkey.reserved = *p++; memcpy( rec->r.pubkey.fingerprint, p, 20); p += 20; rec->r.pubkey.ownertrust = *p++; if( rec->r.pubkey.local_id != recnum ) { log_error("%s: pubkey local_id != recnum (%lu,%lu)\n", db_name, (ulong)rec->r.pubkey.local_id, (ulong)recnum ); rc = G10ERR_TRUSTDB; } break; case 3: rec->r.cache.owner = buftoulong(p); p += 4; rec->r.cache.keyid[0] = buftou32(p); p += 4; rec->r.cache.keyid[1] = buftou32(p); p += 4; rec->r.cache.valid = *p++; rec->r.cache.reserved = *p++; memcpy(rec->r.cache.blockhash, p, 20); p += 20; rec->r.cache.n_untrusted = *p++; rec->r.cache.n_marginal = *p++; rec->r.cache.n_fully = *p++; rec->r.cache.trustlevel = *p++; break; case 4: case 5: rec->r.sigrec.owner = buftoulong(p); p += 4; rec->r.sigrec.chain = buftoulong(p); p += 4; for(i=0; i < SIGS_PER_RECORD; i++ ) { rec->r.sigrec.sig[i].local_id = buftoulong(p); p += 4; rec->r.sigrec.sig[i].flag = *p++; } break; default: log_error("%s: invalid record type %d at recnum %lu\n", db_name, rec->rectype, (ulong)recnum ); rc = G10ERR_TRUSTDB; break; } if( DBG_TRUST && !rc && !no_io_dbg ) { log_debug("trustdb: "); dump_record( recnum, rec, stderr); } return rc; } /**************** * Write the record at RECNUM */ static int write_record( ulong recnum, TRUSTREC *rec ) { byte buf[TRUST_RECORD_LEN], *p; int rc = 0; int i, n; if( db_fd == -1 ) open_db(); if( DBG_TRUST && !no_io_dbg ) log_debug("trustdb: write_record(%lu)\n", (ulong)recnum); memset(buf, 0, TRUST_RECORD_LEN); p = buf; *p++ = rec->rectype; *p++ = rec->reserved; switch( rec->rectype ) { case 0: /* unused record */ break; case 1: /* version record */ BUG(); break; case 2: ulongtobuf(p, rec->r.pubkey.local_id); p += 4; u32tobuf(p, rec->r.pubkey.keyid[0]); p += 4; u32tobuf(p, rec->r.pubkey.keyid[1]); p += 4; *p++ = rec->r.pubkey.pubkey_algo; *p++ = rec->r.pubkey.reserved; memcpy( p, rec->r.pubkey.fingerprint, 20); p += 20; *p++ = rec->r.pubkey.ownertrust; assert( rec->r.pubkey.local_id == recnum ); break; case 3: ulongtobuf(p, rec->r.cache.owner); p += 4; u32tobuf(p, rec->r.cache.keyid[0]); p += 4; u32tobuf(p, rec->r.cache.keyid[1]); p += 4; *p++ = rec->r.cache.valid; *p++ = rec->r.cache.reserved; memcpy(p, rec->r.cache.blockhash, 20); p += 20; *p++ = rec->r.cache.n_untrusted; *p++ = rec->r.cache.n_marginal; *p++ = rec->r.cache.n_fully; *p++ = rec->r.cache.trustlevel; break; case 4: case 5: ulongtobuf(p, rec->r.sigrec.owner); p += 4; ulongtobuf(p, rec->r.sigrec.chain); p += 4; for(i=0; i < SIGS_PER_RECORD; i++ ) { ulongtobuf(p, rec->r.sigrec.sig[i].local_id); p += 4; *p++ = rec->r.sigrec.sig[i].flag; } break; default: BUG(); } if( lseek( db_fd, recnum * TRUST_RECORD_LEN, SEEK_SET ) == -1 ) { log_error("trustdb: lseek failed: %s\n", strerror(errno) ); return G10ERR_WRITE_FILE; } n = write( db_fd, buf, TRUST_RECORD_LEN); if( n != TRUST_RECORD_LEN ) { log_error("trustdb: write failed (n=%d): %s\n", n, strerror(errno) ); return G10ERR_WRITE_FILE; } return rc; } /**************** * create a new record and return its record number */ static ulong new_recnum() { off_t offset; ulong recnum; TRUSTREC rec; int rc; /* fixme: look for unused records */ 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; assert(recnum); /* this is 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; /* free record */ rc = write_record(recnum, &rec ); if( rc ) log_fatal("%s: failed to append a record: %s\n", db_name, g10_errstr(rc)); return recnum ; } /**************** * Scan the trustdb for a record of type RECTYPE which matches PKC * The local_id is set to the correct value */ static int scan_record_by_pkc( PKT_public_cert *pkc, TRUSTREC *rec, int rectype ) { ulong recnum; u32 keyid[2]; byte *fingerprint; size_t fingerlen; int rc; assert( rectype == 2 || rectype == 3 ); if( DBG_TRUST ) log_debug("trustdb: scan_record_by_pkc\n"); keyid_from_pkc( pkc, keyid ); fingerprint = fingerprint_from_pkc( pkc, &fingerlen ); assert( fingerlen == 20 || fingerlen == 16 ); no_io_dbg = 1; for(recnum=1; !(rc=read_record( recnum, rec)); recnum++ ) { if( rec->rectype != rectype ) continue; if( rec->rectype == 2 ) { if( rec->r.pubkey.keyid[0] == keyid[0] && rec->r.pubkey.keyid[1] == keyid[1] && rec->r.pubkey.pubkey_algo == pkc->pubkey_algo && !memcmp(rec->r.pubkey.fingerprint, fingerprint, fingerlen) ) { /* found */ /* store the local_id */ if( pkc->local_id && pkc->local_id != recnum ) log_error("%s: found record, but local_id from mem does " "not match recnum (%lu,%lu)\n", db_name, (ulong)pkc->local_id, (ulong)recnum ); pkc->local_id = recnum; no_io_dbg = 0; return 0; } } else log_bug("not yet implemented\n"); } no_io_dbg = 0; if( DBG_TRUST ) log_debug("trustdb: scan_record_by_pkc: %s\n", rc==-1?"eof": g10_errstr(rc)); if( rc != -1 ) log_error("%s: scan_record_by_pkc failed: %s\n",db_name, g10_errstr(rc) ); return rc; } /**************** * scan the DB for a record of type RECTYPE which can be localized * with LOCAL_ID */ static int scan_record( ulong local_id, TRUSTREC *rec, int rectype, ulong *r_recnum ) { ulong recnum; int rc; assert( rectype == 3 || rectype == 4 ); if( DBG_TRUST ) log_debug("trustdb: scan_record type %d local_id %lu\n", rectype, (ulong)local_id); no_io_dbg = 1; for(recnum=1; !(rc=read_record( recnum, rec)); recnum++ ) { if( rec->rectype != rectype ) continue; if( rec->rectype == 34 ) { if( rec->r.cache.owner == local_id ) { /* found */ *r_recnum = recnum; no_io_dbg = 0; return 0; } } else if( rec->rectype == 4 ) { if( rec->r.sigrec.owner == local_id ) { /* found */ *r_recnum = recnum; no_io_dbg = 0; return 0; } } else log_bug("not yet implemented\n"); } no_io_dbg = 0; if( DBG_TRUST ) log_debug("trustdb: scan_record: %s\n", rc==-1?"eof": g10_errstr(rc)); if( rc != -1 ) log_error("%s: scan_record failed: %s\n",db_name, g10_errstr(rc) ); return rc; } static void dump_record( ulong rnum, TRUSTREC *rec, FILE *fp ) { int i, any; fprintf(fp, "trust record %lu, type=", rnum ); switch( rec->rectype ) { case 0: fprintf(fp, "free\n"); break; case 1: fprintf(fp, "version\n"); break; case 2: fprintf(fp, "pubkey, keyid=%08lX, ownertrust=%02x\n", rec->r.pubkey.keyid[1], rec->r.pubkey.ownertrust ); break; case 3: fprintf(fp, "cache\n"); case 4: case 5: fprintf(fp, "sigrec, owner=%lu, chain=%lu%s\n", rec->r.sigrec.owner, rec->r.sigrec.chain, rec->rectype == 4?"":" (extend)"); for(i=any=0; i < SIGS_PER_RECORD; i++ ) { if( rec->r.sigrec.sig[i].local_id ) { if( !any ) { putc('\t', fp); any++; } fprintf(fp, " %lu:%02x", rec->r.sigrec.sig[i].local_id, rec->r.sigrec.sig[i].flag ); } } if( any ) putc('\n', fp); break; default: fprintf(fp, "%d (unknown)\n", rec->rectype ); break; } } /**************** * If we do not have a local_id in a signature packet, find the owner of * the signature packet in our trustdb or insert him into the trustdb */ static int set_signature_packets_local_id( PKT_signature *sig ) { PKT_public_cert *pkc = m_alloc_clear( sizeof *pkc ); TRUSTREC rec; int rc; rc = get_pubkey( pkc, sig->keyid ); if( rc) goto leave; if( !pkc->local_id ) { rc = scan_record_by_pkc( pkc, &rec, 2 ); if( rc == -1 ) rc = insert_trust_record( pkc ); if( rc ) goto leave; /* fixme: we should propagate the local_id to all copies of the PKC */ } sig->local_id = pkc->local_id; leave: free_public_cert( pkc ); return rc; } void list_trustdb( const char *username ) { TRUSTREC rec; if( username ) { PKT_public_cert *pkc = m_alloc_clear( sizeof *pkc ); int rc; if( (rc = get_pubkey_byname( pkc, username )) ) log_error("user '%s' not found: %s\n", username, g10_errstr(rc) ); else if( (rc=scan_record_by_pkc( pkc, &rec, 2 )) && rc != -1 ) log_error("problem finding '%s' in trustdb: %s\n", username, g10_errstr(rc)); else if( rc == -1 ) log_error("user '%s' not in trustdb\n", username); else if( (rc = list_sigs( pkc->local_id )) ) log_error("user '%s' list problem: %s\n", username, g10_errstr(rc)); free_public_cert( pkc ); } else { ulong recnum; int i; printf("TrustDB: %s\n", db_name ); for(i=9+strlen(db_name); i > 0; i-- ) putchar('-'); putchar('\n'); no_io_dbg = 1; for(recnum=0; !read_record( recnum, &rec); recnum++ ) dump_record( recnum, &rec, stdout ); no_io_dbg = 0; } } void list_trust_path( int max_depth, const char *username ) { int rc; TRUSTREC rec; PKT_public_cert *pkc = m_alloc_clear( sizeof *pkc ); if( max_depth < 1 ) max_depth = MAX_LIST_SIGS_DEPTH+1; if( (rc = get_pubkey_byname( pkc, username )) ) log_error("user '%s' not found: %s\n", username, g10_errstr(rc) ); else if( (rc=scan_record_by_pkc( pkc, &rec, 2 )) && rc != -1 ) log_error("problem finding '%s' in trustdb: %s\n", username, g10_errstr(rc)); else if( rc == -1 ) log_error("user '%s' not in trustdb\n", username); else { LOCAL_ID_INFO *lids; ulong stack[MAX_LIST_SIGS_DEPTH]; lids = new_lid_table(); stack[0] = pkc->local_id; rc = do_list_path( pkc->local_id, 1, max_depth, lids, stack ); putchar('\n'); release_lid_table(lids); if( rc ) log_error("user '%s' list problem: %s\n", username, g10_errstr(rc)); } free_public_cert( pkc ); } /**************** * Walk throug the signatures of a public key. * The caller must provide a context structure, with all fields set * to zero, but the pubkeyid filed set to the requested pubkey; * This function does not change this field. On return the context * is filled with the local-id of the signature and the signature flag. * No fields should be changed (clearing all fields and setting * pubkeyid is okay to continue with an other pubkey) * Returns: 0 - okay, -1 for eof (no more sigs) or any other errorcode */ static int walk_sigrecs( SIGREC_CONTEXT *c ) { int rc=0; TRUSTREC *r; ulong rnum; if( c->ctl.eof ) return -1; r = &c->ctl.rec; if( !r->rectype ) { /* this is the first call */ rc = scan_record( c->pubkey_id, r, 4, &rnum ); if( rc == -1 ) { /* no signature records */ c->ctl.eof = 1; return -1; /* return eof */ } if( rc ) { log_error("scan_record(sigrec) failed: %s\n", g10_errstr(rc)); c->ctl.eof = 1; return rc; } c->ctl.index = 0; } /* enter loop to skip deleted sigs */ do { if( c->ctl.index >= SIGS_PER_RECORD ) { /* read the next record */ if( !r->r.sigrec.chain ) { c->ctl.eof = 1; return -1; /* return eof */ } rnum = r->r.sigrec.chain; rc = read_record( rnum, r ); if( rc ) { log_error("error reading next sigrec: %s\n", g10_errstr(rc)); c->ctl.eof = 1; return rc; } if( r->r.sigrec.owner != c->pubkey_id ) { log_error("chained sigrec %lu has a wrong owner\n", rnum ); c->ctl.eof = 1; return G10ERR_TRUSTDB; } c->ctl.index = 0; } } while( !r->r.sigrec.sig[c->ctl.index++].local_id ); c->sig_id = r->r.sigrec.sig[c->ctl.index-1].local_id; c->sig_flag = r->r.sigrec.sig[c->ctl.index-1].flag; return 0; } /*********************************************** ************* trust logic ******************* ***********************************************/ static LOCAL_ID_INFO * new_lid_table(void) { return m_alloc_clear( 16 * sizeof(LOCAL_ID_INFO)); } static void release_lid_table( LOCAL_ID_INFO *tbl ) { LOCAL_ID_INFO a, a2; int i; for(i=0; i < 16; i++ ) { for(a=tbl[i]; a; a = a2 ) { a2 = a->next; m_free(a); } } m_free(tbl); } /**************** * Add a new item to the table or return 1 if we aread have this item * fixme: maybe its a good idea to tage items from an unused item list. */ static int add_lid_table_item( LOCAL_ID_INFO *tbl, ulong lid, unsigned flag ) { LOCAL_ID_INFO a; for( a = tbl[lid & 0x0f]; a; a = a->next ) if( a->lid == lid ) return 1; a = m_alloc( sizeof *a ); a->lid = lid; a->flag = flag; a->next = tbl[lid & 0x0f]; tbl[lid & 0x0f] = a; return 0; } static int get_lid_table_flag( LOCAL_ID_INFO *tbl, ulong lid, unsigned *flag ) { LOCAL_ID_INFO a; for( a = tbl[lid & 0x0f]; a; a = a->next ) if( a->lid == lid ) { if( flag ) *flag = a->flag; return 0; } return -1; } static int keyid_from_local_id( ulong lid, u32 *keyid ) { TRUSTREC rec; int rc; rc = read_record( lid, &rec ); if( rc ) { log_error("error reading record with local_id %lu: %s\n", lid, g10_errstr(rc)); return G10ERR_TRUSTDB; } if( rec.rectype != 2 ) { log_error("record with local_id %lu is not a pubkey record\n", lid); return G10ERR_TRUSTDB; } keyid[0] = rec.r.pubkey.keyid[0]; keyid[1] = rec.r.pubkey.keyid[1]; return 0; } /**************** * Verify, that all our public keys are in the trustDB and marked as * ultimately trusted. */ static int verify_own_certs() { int rc; void *enum_context = NULL; PKT_secret_cert *skc = m_alloc_clear( sizeof *skc ); PKT_public_cert *pkc = m_alloc_clear( sizeof *pkc ); u32 keyid[2]; int trust; while( !(rc=enum_secret_keys( &enum_context, skc) ) ) { /* fixed: to be sure that it is a secret key of our own, * we should check it, but this needs a passphrase * for every key and this boring for the user. * Solution: Sign the secring and the trustring * and verify this signature during * startup */ keyid_from_skc( skc, keyid ); if( DBG_TRUST ) log_debug("checking secret key %08lX\n", (ulong)keyid[1] ); /* look wether we can access the public key of this secret key */ rc = get_pubkey( pkc, keyid ); if( rc ) { log_error("keyid %08lX: secret key without public key\n", (ulong)keyid[1] ); goto leave; } if( cmp_public_secret_cert( pkc, skc ) ) { log_error("keyid %08lX: secret and public key don't match\n", (ulong)keyid[1] ); rc = G10ERR_GENERAL; goto leave; } /* look into the trustdb */ rc = check_pkc_trust( pkc, &trust ); if( rc ) { log_info("keyid %08lX: problem in trustdb: %s\n", (ulong)keyid[1], g10_errstr(rc) ); goto leave; } if( trust & TRUST_NO_PUBKEY ) { log_info("keyid %08lX: not yet in trustdb\n", (ulong)keyid[1] ); rc = insert_trust_record( pkc ); if( rc ) log_error("keyid %08lX: insert failed: %s\n", (ulong)keyid[1], g10_errstr(rc) ); else log_info("keyid %08lX: inserted\n", (ulong)keyid[1] ); } else if( (trust & TRUST_MASK) != TRUST_ULT_TRUST ) { /*log_error("keyid %08lX: not marked as ultimately trusted\n", (ulong)keyid[1] ); FIXME: mark */ } if( !(trust & TRUST_NO_PUBKEY) ) { if( DBG_TRUST ) log_debug("putting %08lX(%lu) into ultikey_table\n", (ulong)keyid[1], pkc->local_id ); if( add_lid_table_item( ultikey_table, pkc->local_id, 0 ) ) log_error("keyid %08lX: already in ultikey_table\n", (ulong)keyid[1]); } release_secret_cert_parts( skc ); release_public_cert_parts( pkc ); } if( rc != -1 ) log_error("enum_secret_keys failed: %s\n", g10_errstr(rc) ); else rc = 0; leave: free_secret_cert( skc ); free_public_cert( pkc ); return rc; } static void print_user_id( const char *text, u32 *keyid ) { char *p; size_t n; p = get_user_id( keyid, &n ); if( *text ) { fputs( text, stdout); putchar(' '); } putchar('\"'); print_string( stdout, p, n ); putchar('\"'); putchar('\n'); m_free(p); } /* (a non-recursive algorithm would be easier) */ static int do_list_sigs( ulong root, ulong pubkey, int depth, LOCAL_ID_INFO *lids, unsigned *lineno ) { SIGREC_CONTEXT sx; int rc; u32 keyid[2]; memset( &sx, 0, sizeof sx ); sx.pubkey_id = pubkey; for(;;) { rc = walk_sigrecs( &sx ); if( rc ) break; rc = keyid_from_local_id( sx.sig_id, keyid ); if( rc ) { printf("%6u: %*s????????(%lu:%02x)\n", *lineno, depth*4, "", sx.sig_id, sx.sig_flag ); ++*lineno; } else { printf("%6u: %*s%08lX(%lu:%02x) ", *lineno, depth*4, "", (ulong)keyid[1], sx.sig_id, sx.sig_flag ); /* check wether we already checked this pubkey */ if( !get_lid_table_flag( ultikey_table, sx.sig_id, NULL ) ) { print_user_id("[ultimately trusted]", keyid); ++*lineno; } else if( sx.sig_id == pubkey ) { printf("[self-signature]\n"); ++*lineno; } else if( sx.sig_id == root ) { printf("[closed]\n"); ++*lineno; } else if( add_lid_table_item( lids, sx.sig_id, *lineno ) ) { unsigned refline; get_lid_table_flag( lids, sx.sig_id, &refline ); printf("[see line %u]\n", refline); ++*lineno; } else if( depth+1 >= MAX_LIST_SIGS_DEPTH ) { print_user_id( "[too deeply nested]", keyid ); ++*lineno; } else { print_user_id( "", keyid ); ++*lineno; rc = do_list_sigs( root, sx.sig_id, depth+1, lids, lineno ); if( rc ) break; } } } return rc==-1? 0 : rc; } /**************** * List all signatures of a public key */ static int list_sigs( ulong pubkey_id ) { int rc; u32 keyid[2]; LOCAL_ID_INFO *lids; unsigned lineno = 1; rc = keyid_from_local_id( pubkey_id, keyid ); if( rc ) { log_error("Hmmm, no pubkey record for local_id %lu\n", pubkey_id); return rc; } printf("Signatures of %08lX(%lu) ", (ulong)keyid[1], pubkey_id ); print_user_id("", keyid); printf("----------------------\n"); lids = new_lid_table(); rc = do_list_sigs( pubkey_id, pubkey_id, 0, lids, &lineno ); putchar('\n'); release_lid_table(lids); return rc; } static int do_list_path( ulong pubkey, int depth, int max_depth, LOCAL_ID_INFO *lids, ulong *stack ) { SIGREC_CONTEXT sx; int rc; if( depth > max_depth || depth >= MAX_LIST_SIGS_DEPTH ) return 0; if( !get_lid_table_flag( ultikey_table, pubkey, NULL ) ) { /* found a path */ int i; u32 keyid[2]; for(i=0; i < depth; i++ ) { if( keyid_from_local_id( stack[i], keyid ) ) printf("%*s????????(%lu) ", i*4,"", stack[i] ); else { printf("%*s%08lX(%lu) ", i*4,"", keyid[1], stack[i] ); print_user_id("", keyid ); } } putchar('\n'); return 0; } if( add_lid_table_item( lids, pubkey, 0 ) ) return 0; memset( &sx, 0, sizeof sx ); sx.pubkey_id = pubkey; do { rc = walk_sigrecs( &sx ); if( !rc ) { stack[depth] = sx.sig_id; rc = do_list_path( sx.sig_id, depth+1, max_depth, lids, stack ); } } while( !rc ); return rc==-1? 0 : rc; } /**************** * Check all the sigs of the given keyblock and mark them * as checked. */ static int check_sigs( KBNODE keyblock, int *selfsig_okay ) { KBNODE kbctx; KBNODE node; int rc; *selfsig_okay = 0; for( kbctx=NULL; (node=walk_kbtree( keyblock, &kbctx)) ; ) { if( node->pkt->pkttype == PKT_SIGNATURE && (node->pkt->pkt.signature->sig_class&~3) == 0x10 ) { int selfsig; rc = check_key_signature( keyblock, node, &selfsig ); if( !rc ) { if( selfsig ) { node->flag |= 2; /* mark signature valid */ *selfsig_okay = 1; } else node->flag |= 1; /* mark signature valid */ } if( DBG_TRUST ) log_debug("trustdb: sig from %08lX: %s\n", (ulong)node->pkt->pkt.signature->keyid[1], g10_errstr(rc) ); } } return 0; } /**************** * If we do not have sigrecs for the given key, build them and write them * to the trustdb */ static int build_sigrecs( ulong pubkeyid ) { TRUSTREC rec, rec2; PUBKEY_FIND_INFO finfo=NULL; KBPOS kbpos; KBNODE keyblock = NULL; KBNODE kbctx; KBNODE node; int rc=0; int i, selfsig; ulong rnum, rnum2; if( DBG_TRUST ) log_debug("trustdb: build_sigrecs for pubkey %lu\n", (ulong)pubkeyid ); /* get the keyblock */ if( (rc=read_record( pubkeyid, &rec )) ) { log_error("build_sigrecs: can't read pubkey record\n"); goto leave; } finfo = m_alloc_clear( sizeof *finfo ); finfo->keyid[0] = rec.r.pubkey.keyid[0]; finfo->keyid[1] = rec.r.pubkey.keyid[1]; finfo->pubkey_algo = rec.r.pubkey.pubkey_algo; memcpy( finfo->fingerprint, rec.r.pubkey.fingerprint, 20); rc = find_keyblock( finfo, &kbpos ); if( rc ) { log_error("build_sigrecs: find_keyblock failed\n" ); goto leave; } rc = read_keyblock( &kbpos, &keyblock ); if( rc ) { log_error("build_sigrecs: read_keyblock failed\n" ); goto leave; } /* check all key signatures */ rc = check_sigs( keyblock, &selfsig ); if( rc ) { log_error("build_sigrecs: check_sigs failed\n" ); goto leave; } if( !selfsig ) { log_error("build_sigrecs: self-certificate missing\n" ); rc = G10ERR_BAD_CERT; goto leave; } /* valid key signatures are now marked; we can now build the * sigrecs */ memset( &rec, 0, sizeof rec ); rec.rectype = 4; i = 0; rnum = rnum2 = 0; for( kbctx=NULL; (node=walk_kbtree( keyblock, &kbctx)) ; ) { if( node->flag & 1 ) { assert( node->pkt->pkttype == PKT_SIGNATURE ); if( !node->pkt->pkt.signature->local_id ) { /* the next function should always succeed, because * we have already checked the signature, and for this * it was necessary to have the pubkey. The only reason * this can fail are I/o erros of the trustdb. */ rc = set_signature_packets_local_id( node->pkt->pkt.signature ); if( rc ) log_fatal("set_signature_packets_local_id failed: %s\n", g10_errstr(rc)); } if( i == SIGS_PER_RECORD ) { /* write the record */ rnum = new_recnum(); if( rnum2 ) { /* write the stored record */ rec2.r.sigrec.owner = pubkeyid; rec2.r.sigrec.chain = rnum; /* the next record number */ rc = write_record( rnum2, &rec2 ); if( rc ) { log_error("build_sigrecs: write_record failed\n" ); goto leave; } } rec2 = rec; rnum2 = rnum; memset( &rec, 0, sizeof rec ); rec.rectype = 5; i = 0; } rec.r.sigrec.sig[i].local_id = node->pkt->pkt.signature->local_id; rec.r.sigrec.sig[i].flag = 0; i++; } } if( i || rnum2 ) { /* write the record */ rnum = new_recnum(); if( rnum2 ) { /* write the stored record */ rec2.r.sigrec.owner = pubkeyid; rec2.r.sigrec.chain = rnum; rc = write_record( rnum2, &rec2 ); if( rc ) { log_error("build_sigrecs: write_record failed\n" ); goto leave; } } if( i ) { /* write the pending record */ rec.r.sigrec.owner = pubkeyid; rec.r.sigrec.chain = 0; rc = write_record( rnum, &rec ); if( rc ) { log_error("build_sigrecs: write_record failed\n" ); goto leave; } } } leave: m_free( finfo ); release_kbnode( keyblock ); if( DBG_TRUST ) log_debug("trustdb: build_sigrecs: %s\n", g10_errstr(rc) ); return rc; } /**************** * Recursive check the signatures. */ #if 0 static int walk( KBNODE keyblock, int levels ) { KBNODE kbctx, node; check_sigs( keyblock ); if( levels ) { /* check the next level */ for( kbctx=NULL; (node=walk_kbtree( keyblock, &kbctx)) ; ) { if( node->pkt->pkttype == PKT_SIGNATURE && (node->flag & 1) ) { /* read the keyblock for this signator */ /* and check his signatures */ /*walk( his_keyblock, levels-1)*/ } } } return -1; } #endif /**************** * */ static int check_trust( ulong pubkeyid ) { int rc=0; ulong rnum; TRUSTREC rec; /* verify the cache */ /* do we have sigrecs */ rc = scan_record( pubkeyid, &rec, 4, &rnum ); if( rc == -1 ) { /* no sigrecs, so build them */ rc = build_sigrecs( pubkeyid ); if( !rc ) /* and read again */ rc = scan_record( pubkeyid, &rec, 4, &rnum ); } if( rc ) return rc; /* error while looking for sigrec or building sigrecs */ return 0; } /********************************************************* **************** API Interface ************************ *********************************************************/ /**************** * Perform some checks over the trustdb * level 0: only open the db * 1: used for initial program startup */ int init_trustdb( int level ) { int rc=0; if( !ultikey_table ) ultikey_table = new_lid_table(); if( !level || level==1 ) { char *fname = make_filename("~/.g10", "trustdb.g10", 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; } if( level ) create_db( fname ); } m_free(db_name); db_name = fname; if( !level ) return 0; /* we can verify a signature about our local data (secring and trustdb) * in ~/.g10/ here */ rc = verify_private_data(); if( !rc ) { /* verify, that our own certificates are in the trustDB * or move them to the trustdb. */ rc = verify_own_certs(); /* should we check wether there is no other ultimately trusted * key in the database? */ } } else BUG(); return rc; } /**************** * 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 and all the other stuff * 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 ) { TRUSTREC rec; int trustlevel = 0; int rc=0; if( opt.verbose ) log_info("check_pkc_trust() called.\n"); /* get the pubkey record */ if( pkc->local_id ) { if( read_record( pkc->local_id, &rec ) ) { log_error("check_pkc_trust: read record failed\n"); return G10ERR_TRUSTDB; } } else { /* no local_id: scan the trustdb */ if( (rc=scan_record_by_pkc( pkc, &rec, 2 )) && rc != -1 ) { log_error("check_pkc_trust: scan_record_by_pkc(2) failed: %s\n", g10_errstr(rc)); return rc; } else if( rc == -1 ) { log_error("check_pkc_trust: pubkey not in TrustDB\n"); trustlevel = TRUST_NO_PUBKEY; goto leave; } } /* fixme: do some additional checks on the pubkey record */ rc = check_trust( pkc->local_id ); if( rc ) { log_error("check_pkc_trust: check_trust failed: %s\n", g10_errstr(rc)); return rc; } leave: if( opt.verbose ) log_info("check_pkc_trust() returns trustlevel %04x.\n", trustlevel); *r_trustlevel = trustlevel; return 0; } int get_ownertrust( PKT_public_cert *pkc, int *r_otrust ) { TRUSTREC rec; int rc; /* get the pubkey record */ if( pkc->local_id ) { if( read_record( pkc->local_id, &rec ) ) { log_error("get_ownertrust: read record failed\n"); return G10ERR_TRUSTDB; } } else { /* no local_id: scan the trustdb */ if( (rc=scan_record_by_pkc( pkc, &rec, 2 )) && rc != -1 ) { log_error("get_ownertrust: scan_record_by_pkc(2) failed: %s\n", g10_errstr(rc)); return rc; } else if( rc == -1 ) return rc; } *r_otrust = rec.r.pubkey.ownertrust; return 0; } /**************** * Insert a trust record into the TrustDB * This function failes if this record already exists. */ int insert_trust_record( PKT_public_cert *pkc ) { TRUSTREC rec; u32 keyid[2]; ulong recnum; byte *fingerprint; size_t fingerlen; if( DBG_TRUST ) log_debug("trustdb: insert_record\n"); if( pkc->local_id ) log_bug("pkc->local_id=%lu\n", (ulong)pkc->local_id ); keyid_from_pkc( pkc, keyid ); fingerprint = fingerprint_from_pkc( pkc, &fingerlen ); /* FIXME: check that we do not have this record. */ recnum = new_recnum(); /* build record */ memset( &rec, 0, sizeof rec ); rec.rectype = 2; /* the pubkey record */ rec.r.pubkey.local_id = recnum; rec.r.pubkey.keyid[0] = keyid[0]; rec.r.pubkey.keyid[1] = keyid[1]; rec.r.pubkey.pubkey_algo = pkc->pubkey_algo; memcpy(rec.r.pubkey.fingerprint, fingerprint, fingerlen ); rec.r.pubkey.ownertrust = 0; if( write_record( recnum, &rec ) ) { log_error("insert_trust_record: write failed\n"); return G10ERR_TRUSTDB; } pkc->local_id = recnum; return 0; } int update_trust_record( PKT_public_cert *pkc, int new_trust ) { TRUSTREC rec; ulong recnum; if( DBG_TRUST ) log_debug("trustdb: update_record\n"); assert( pkc->local_id ); if( read_record( pkc->local_id, &rec ) ) { log_error("update_trust_record: read failed\n"); return G10ERR_TRUSTDB; } /* check keyid, fingerprint etc ? */ rec.r.pubkey.ownertrust = 0; if( write_record( recnum, &rec ) ) { log_error("insert_trust_record: write failed\n"); return G10ERR_TRUSTDB; } return 0; } int verify_private_data() { int rc = 0; char *sigfile = make_filename("~/.g10", "sig", NULL ); if( access( sigfile, R_OK ) ) { if( errno != ENOENT ) { log_error("can't access %s: %s\n", sigfile, strerror(errno) ); rc = G10ERR_TRUSTDB; goto leave; } log_info("private data signature missing; creating ...\n"); rc = sign_private_data(); if( rc ) { log_error("error creating %s: %s\n", sigfile, g10_errstr(rc) ); goto leave; } } /* FIXME: verify this signature */ leave: m_free(sigfile); return rc; } int sign_private_data() { int rc; char *sigfile = make_filename("~/.g10", "sig", NULL ); char *secring = make_filename("~/.g10", "secring.g10", NULL ); STRLIST list = NULL; add_to_strlist( &list, db_name ); add_to_strlist( &list, secring ); rc = sign_file( list, 1, NULL, 0, NULL, sigfile); m_free(sigfile); m_free(secring); free_strlist(list); return rc; }