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gnupg/g10/mainproc.c

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/* mainproc.c - handle packets
* 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 <assert.h>
#include "packet.h"
#include "iobuf.h"
#include "memory.h"
#include "options.h"
#include "util.h"
#include "cipher.h"
#include "keydb.h"
#include "filter.h"
#include "cipher.h"
#include "main.h"
/****************
* Structure to hold the context
*/
typedef struct {
PKT_public_cert *last_pubkey;
PKT_secret_cert *last_seckey;
PKT_user_id *last_user_id;
md_filter_context_t mfx;
DEK *dek;
int last_was_pubkey_enc;
KBNODE cert; /* the current certificate */
int have_data;
IOBUF iobuf; /* used to get the filename etc. */
} *CTX;
static void list_node( CTX c, KBNODE node );
static void proc_tree( CTX c, KBNODE node );
static void
release_cert( CTX c )
{
if( !c->cert )
return;
proc_tree(c, c->cert );
release_kbnode( c->cert );
c->cert = NULL;
}
static int
add_onepass_sig( CTX c, PACKET *pkt )
{
KBNODE node;
if( c->cert ) { /* add another packet */
if( c->cert->pkt->pkttype != PKT_ONEPASS_SIG ) {
log_error("add_onepass_sig: another packet is in the way\n");
release_cert( c );
}
node = new_kbnode( pkt );
node->next = c->cert;
c->cert = node;
}
else /* insert the first one */
c->cert = node = new_kbnode( pkt );
return 1;
}
static int
add_public_cert( CTX c, PACKET *pkt )
{
release_cert( c );
c->cert = new_kbnode( pkt );
return 1;
}
static int
add_secret_cert( CTX c, PACKET *pkt )
{
release_cert( c );
c->cert = new_kbnode( pkt );
return 1;
}
static int
add_user_id( CTX c, PACKET *pkt )
{
u32 keyid[2];
KBNODE node, n1, n2;
if( !c->cert ) {
log_error("orphaned user id\n" );
return 0;
}
/* goto the last certificate (currently ther is only one) */
for(n1=c->cert; n1->next; n1 = n1->next )
;
assert( n1->pkt );
if( n1->pkt->pkttype != PKT_PUBLIC_CERT
&& n1->pkt->pkttype != PKT_SECRET_CERT ) {
log_error("invalid parent type %d for userid\n", n1->pkt->pkttype );
return 0;
}
/* add a new user id node at the end */
node = new_kbnode( pkt );
if( !(n2=n1->child) )
n1->child = node;
else {
for( ; n2->next; n2 = n2->next)
;
n2->next = node;
}
return 1;
}
static int
add_signature( CTX c, PACKET *pkt )
{
u32 keyid[2];
KBNODE node, n1, n2;
if( !c->cert ) {
/* orphaned signature (no certificate)
* this is the first signature for a following datafile
*/
return 0;
}
assert( c->cert->pkt );
if( c->cert->pkt->pkttype == PKT_ONEPASS_SIG ) {
/* The root is a onepass signature, so we are signing data
* The childs direct under the root are the signatures
* (there is no need to keep the correct sequence of packets)
*/
node = new_kbnode( pkt );
node->next = c->cert->child;
c->cert->child = node;
return 1;
}
if( !c->cert->child ) {
log_error("orphaned signature (no userid)\n" );
return 0;
}
/* goto the last user id */
for(n1=c->cert->child; n1->next; n1 = n1->next )
;
assert( n1->pkt );
if( n1->pkt->pkttype != PKT_USER_ID ) {
log_error("invalid parent type %d for sig\n", n1->pkt->pkttype);
return 0;
}
/* and add a new signature node id at the end */
node = new_kbnode( pkt );
if( !(n2=n1->child) )
n1->child = node;
else {
for( ; n2->next; n2 = n2->next)
;
n2->next = node;
}
return 1;
}
static void
proc_pubkey_enc( CTX c, PACKET *pkt )
{
PKT_pubkey_enc *enc;
int result = 0;
c->last_was_pubkey_enc = 1;
enc = pkt->pkt.pubkey_enc;
/*printf("enc: encrypted by a pubkey with keyid %08lX\n", enc->keyid[1] );*/
if( enc->pubkey_algo == PUBKEY_ALGO_ELGAMAL
|| enc->pubkey_algo == PUBKEY_ALGO_RSA ) {
m_free(c->dek ); /* paranoid: delete a pending DEK */
c->dek = m_alloc_secure( sizeof *c->dek );
if( (result = get_session_key( enc, c->dek )) ) {
/* error: delete the DEK */
m_free(c->dek); c->dek = NULL;
}
}
else
result = G10ERR_PUBKEY_ALGO;
if( result == -1 )
;
else if( !result ) {
if( opt.verbose > 1 )
log_info( "pubkey_enc packet: Good DEK\n" );
}
else
log_error( "pubkey_enc packet: %s\n", g10_errstr(result));
free_packet(pkt);
}
static void
proc_encrypted( CTX c, PACKET *pkt )
{
int result = 0;
/*printf("dat: %sencrypted data\n", c->dek?"":"conventional ");*/
if( !c->dek && !c->last_was_pubkey_enc ) {
/* assume this is conventional encrypted data */
c->dek = m_alloc_secure( sizeof *c->dek );
c->dek->algo = opt.def_cipher_algo;
result = make_dek_from_passphrase( c->dek, 0 );
}
else if( !c->dek )
result = G10ERR_NO_SECKEY;
if( !result )
result = decrypt_data( pkt->pkt.encrypted, c->dek );
m_free(c->dek); c->dek = NULL;
if( result == -1 )
;
else if( !result ) {
if( opt.verbose > 1 )
log_info("encryption okay\n");
}
else {
log_error("encryption failed: %s\n", g10_errstr(result));
}
free_packet(pkt);
c->last_was_pubkey_enc = 0;
}
static void
proc_plaintext( CTX c, PACKET *pkt )
{
PKT_plaintext *pt = pkt->pkt.plaintext;
int rc;
if( opt.verbose )
log_info("original file name='%.*s'\n", pt->namelen, pt->name);
free_md_filter_context( &c->mfx );
/* fixme: take the digest algo(s) to use from the
* onepass_sig packet (if we have these)
* And look at the sigclass to check wether we should use the
* textmode filter (sigclass 0x01)
*/
c->mfx.md = md_open( DIGEST_ALGO_RMD160, 0);
rc = handle_plaintext( pt, &c->mfx );
if( rc )
log_error( "handle plaintext failed: %s\n", g10_errstr(rc));
free_packet(pkt);
c->last_was_pubkey_enc = 0;
}
static void
proc_compressed( CTX c, PACKET *pkt )
{
PKT_compressed *zd = pkt->pkt.compressed;
int rc;
/*printf("zip: compressed data packet\n");*/
rc = handle_compressed( zd );
if( rc )
log_error("uncompressing failed: %s\n", g10_errstr(rc));
free_packet(pkt);
c->last_was_pubkey_enc = 0;
}
/****************
* check the signature
* Returns: 0 = valid signature or an error code
*/
static int
do_check_sig( CTX c, KBNODE node )
{
PKT_signature *sig;
MD_HANDLE md;
int algo, rc;
assert( node->pkt->pkttype == PKT_SIGNATURE );
sig = node->pkt->pkt.signature;
if( sig->pubkey_algo == PUBKEY_ALGO_ELGAMAL )
algo = sig->d.elg.digest_algo;
else if(sig->pubkey_algo == PUBKEY_ALGO_RSA )
algo = sig->d.rsa.digest_algo;
else
return G10ERR_PUBKEY_ALGO;
if( (rc=check_digest_algo(algo)) )
return rc;
if( sig->sig_class == 0x00 ) {
md = md_copy( c->mfx.md );
}
else if( (sig->sig_class&~3) == 0x10 ) { /* classes 0x10 .. 0x13 */
if( c->cert->pkt->pkttype == PKT_PUBLIC_CERT ) {
KBNODE n1 = find_kbparent( c->cert, node );
if( n1 && n1->pkt->pkttype == PKT_USER_ID ) {
if( c->cert->pkt->pkt.public_cert->mfx.md )
md = md_copy( c->cert->pkt->pkt.public_cert->mfx.md );
else
log_bug(NULL);
md_write( md, n1->pkt->pkt.user_id->name, n1->pkt->pkt.user_id->len);
}
else {
log_error("invalid parent packet for sigclass 0x10\n");
return G10ERR_SIG_CLASS;
}
}
else {
log_error("invalid root packet for sigclass 0x10\n");
return G10ERR_SIG_CLASS;
}
}
else
return G10ERR_SIG_CLASS;
rc = signature_check( sig, md );
md_close(md);
return rc;
}
static void
print_userid( PACKET *pkt )
{
if( !pkt )
log_bug(NULL);
if( pkt->pkttype != PKT_USER_ID ) {
printf("ERROR: unexpected packet type %d", pkt->pkttype );
return;
}
print_string( stdout, pkt->pkt.user_id->name, pkt->pkt.user_id->len );
}
static void
print_fingerprint( PKT_public_cert *pkc, PKT_secret_cert *skc )
{
byte *array, *p;
size_t i, n;
p = array = skc? fingerprint_from_skc( skc, &n )
: fingerprint_from_pkc( pkc, &n );
printf(" Key fingerprint =");
if( n == 20 ) {
for(i=0; i < n ; i++, i++, p += 2 ) {
if( i == 10 )
putchar(' ');
printf(" %02X%02X", *p, p[1] );
}
}
else {
for(i=0; i < n ; i++, p++ ) {
if( i && !(i%8) )
putchar(' ');
printf(" %02X", *p );
}
}
putchar('\n');
m_free(array);
}
/****************
* List the certificate in a user friendly way
*/
static void
list_node( CTX c, KBNODE node )
{
register KBNODE n2;
if( !node )
;
else if( node->pkt->pkttype == PKT_PUBLIC_CERT ) {
PKT_public_cert *pkc = node->pkt->pkt.public_cert;
printf("pub %4u%c/%08lX %s ", nbits_from_pkc( pkc ),
pubkey_letter( pkc->pubkey_algo ),
(ulong)keyid_from_pkc( pkc, NULL ),
datestr_from_pkc( pkc ) );
n2 = node->child;
if( !n2 )
printf("ERROR: no user id!\n");
else {
/* and now list all userids with their signatures */
for( ; n2; n2 = n2->next ) {
if( n2 != node->child )
printf( "%*s", 31, "" );
print_userid( n2->pkt );
putchar('\n');
if( opt.fingerprint && n2 == node->child )
print_fingerprint( pkc, NULL );
list_node(c, n2 );
}
}
}
else if( node->pkt->pkttype == PKT_SECRET_CERT ) {
PKT_secret_cert *skc = node->pkt->pkt.secret_cert;
printf("sec %4u%c/%08lX %s ", nbits_from_skc( skc ),
pubkey_letter( skc->pubkey_algo ),
(ulong)keyid_from_skc( skc, NULL ),
datestr_from_skc( skc ) );
n2 = node->child;
if( !n2 )
printf("ERROR: no user id!\n");
else {
print_userid( n2->pkt );
putchar('\n');
if( opt.fingerprint && n2 == node->child )
print_fingerprint( NULL, skc );
}
}
else if( node->pkt->pkttype == PKT_USER_ID ) {
/* list everything under this user id */
for(n2=node->child; n2; n2 = n2->next )
list_node(c, n2 );
}
else if( node->pkt->pkttype == PKT_SIGNATURE ) {
PKT_signature *sig = node->pkt->pkt.signature;
int rc2;
size_t n;
char *p;
int sigrc = ' ';
assert( !node->child );
if( !opt.list_sigs )
return;
fputs("sig", stdout);
if( opt.check_sigs ) {
fflush(stdout);
switch( (rc2=do_check_sig( c, node )) ) {
case 0: sigrc = '!'; break;
case G10ERR_BAD_SIGN: sigrc = '-'; break;
case G10ERR_NO_PUBKEY: sigrc = '?'; break;
default: sigrc = '%'; break;
}
}
printf("%c %08lX %s ",
sigrc, sig->keyid[1], datestr_from_sig(sig));
if( sigrc == '%' )
printf("[%s] ", g10_errstr(rc2) );
else if( sigrc == '?' )
;
else {
p = get_user_id( sig->keyid, &n );
print_string( stdout, p, n );
m_free(p);
}
putchar('\n');
}
else
log_error("invalid node with packet of type %d\n", node->pkt->pkttype);
}
int
proc_packets( IOBUF a )
{
CTX c = m_alloc_clear( sizeof *c );
PACKET *pkt = m_alloc( sizeof *pkt );
int rc, result;
int lvl0, lvl1;
u32 keyid[2];
int newpkt;
c->iobuf = a;
init_packet(pkt);
while( (rc=parse_packet(a, pkt)) != -1 ) {
/* cleanup if we have an illegal data structure */
if( c->dek && pkt->pkttype != PKT_ENCRYPTED ) {
log_error("oops: valid pubkey enc packet not followed by data\n");
m_free(c->dek); c->dek = NULL; /* burn it */
}
if( rc ) {
free_packet(pkt);
if( rc == G10ERR_INVALID_PACKET )
break;
continue;
}
newpkt = -1;
if( opt.list_packets ) {
switch( pkt->pkttype ) {
case PKT_PUBKEY_ENC: proc_pubkey_enc( c, pkt ); break;
case PKT_ENCRYPTED: proc_encrypted( c, pkt ); break;
case PKT_COMPRESSED: proc_compressed( c, pkt ); break;
default: newpkt = 0; break;
}
}
else {
switch( pkt->pkttype ) {
case PKT_PUBLIC_CERT: newpkt = add_public_cert( c, pkt ); break;
case PKT_SECRET_CERT: newpkt = add_secret_cert( c, pkt ); break;
case PKT_USER_ID: newpkt = add_user_id( c, pkt ); break;
case PKT_SIGNATURE: newpkt = add_signature( c, pkt ); break;
case PKT_PUBKEY_ENC: proc_pubkey_enc( c, pkt ); break;
case PKT_ENCRYPTED: proc_encrypted( c, pkt ); break;
case PKT_PLAINTEXT: proc_plaintext( c, pkt ); break;
case PKT_COMPRESSED: proc_compressed( c, pkt ); break;
case PKT_ONEPASS_SIG: newpkt = add_onepass_sig( c, pkt ); break;
default: newpkt = 0; break;
}
}
if( pkt->pkttype != PKT_SIGNATURE )
c->have_data = pkt->pkttype == PKT_PLAINTEXT;
if( newpkt == -1 )
;
else if( newpkt ) {
pkt = m_alloc( sizeof *pkt );
init_packet(pkt);
}
else
free_packet(pkt);
}
release_cert( c );
m_free(c->dek);
free_packet( pkt );
m_free( pkt );
free_md_filter_context( &c->mfx );
m_free( c );
return 0;
}
static void
print_keyid( FILE *fp, u32 *keyid )
{
size_t n;
char *p = get_user_id( keyid, &n );
print_string( fp, p, n );
m_free(p);
}
/****************
* Process the tree which starts at node
*/
static void
proc_tree( CTX c, KBNODE node )
{
KBNODE n1;
int rc;
if( opt.list_packets )
return;
if( node->pkt->pkttype == PKT_PUBLIC_CERT )
list_node( c, node );
else if( node->pkt->pkttype == PKT_SECRET_CERT )
list_node( c, node );
else if( node->pkt->pkttype == PKT_ONEPASS_SIG ) {
if( !node->child )
log_error("proc_tree: onepass_sig without data\n");
else if( node->child->pkt->pkttype != PKT_SIGNATURE )
log_error("proc_tree: onepass_sig not followed by signature\n");
else { /* check all signatures */
if( !c->have_data ) {
free_md_filter_context( &c->mfx );
/* fixme: take the digest algo to use from the
* onepass_sig packet (if we have these) */
c->mfx.md = md_open(DIGEST_ALGO_RMD160, 0);
rc = ask_for_detached_datafile( &c->mfx,
iobuf_get_fname(c->iobuf));
if( rc ) {
log_error("can't hash datafile: %s\n", g10_errstr(rc));
return;
}
}
for(n1=node->child; n1; n1 = n1->next ) {
PKT_signature *sig = n1->pkt->pkt.signature;
rc = do_check_sig(c, n1 );
if( !rc ) {
log_info("Good signature from ");
print_keyid( stderr, sig->keyid );
putc('\n', stderr);
}
else if( rc == G10ERR_BAD_SIGN ) {
log_error("BAD signature from ");
print_keyid( stderr, sig->keyid );
putc('\n', stderr);
if( opt.batch )
exit(1);
}
else
log_error("Can't check signature made by %08lX: %s\n",
sig->keyid[1], g10_errstr(rc) );
}
}
}
else if( node->pkt->pkttype == PKT_SIGNATURE ) {
log_info("proc_tree: old style signature\n");
}
else
log_error("proc_tree: invalid root packet\n");
}
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