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gnupg/g10/mainproc.c

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/* mainproc.c - handle packets
* Copyright (C) 1998 Free Software Foundation, Inc.
*
* 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 2 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, 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 <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"
#include "status.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;
int sigs_only; /* process only signatures and reject all other stuff */
int encrypt_only; /* process onyl encrytion messages */
STRLIST signed_data;
DEK *dek;
int last_was_pubkey_enc;
KBNODE list; /* the current list of packets */
int have_data;
IOBUF iobuf; /* used to get the filename etc. */
} *CTX;
static int do_proc_packets( CTX c, IOBUF a );
static void list_node( CTX c, KBNODE node );
static void proc_tree( CTX c, KBNODE node );
static void
release_list( CTX c )
{
if( !c->list )
return;
proc_tree(c, c->list );
release_kbnode( c->list );
c->list = NULL;
}
static int
add_onepass_sig( CTX c, PACKET *pkt )
{
KBNODE node;
if( c->list ) { /* add another packet */
if( c->list->pkt->pkttype != PKT_ONEPASS_SIG ) {
log_error("add_onepass_sig: another packet is in the way\n");
release_list( c );
}
add_kbnode( c->list, new_kbnode( pkt ));
}
else /* insert the first one */
c->list = node = new_kbnode( pkt );
return 1;
}
static int
add_public_cert( CTX c, PACKET *pkt )
{
release_list( c );
c->list = new_kbnode( pkt );
return 1;
}
static int
add_secret_cert( CTX c, PACKET *pkt )
{
release_list( c );
c->list = new_kbnode( pkt );
return 1;
}
static int
add_user_id( CTX c, PACKET *pkt )
{
if( !c->list ) {
log_error("orphaned user id\n" );
return 0;
}
add_kbnode( c->list, new_kbnode( pkt ) );
return 1;
}
static int
add_signature( CTX c, PACKET *pkt )
{
KBNODE node;
if( pkt->pkttype == PKT_SIGNATURE && !c->list ) {
/* This is the first signature for a following datafile.
* G10 does not write such packets, instead it always uses
* onepass-sig packets. The drawback of PGP's method
* of prepending the signtaure to the data is,
* that it is not possible to make a signature from data read
* from stdin. (Anyway, G10 is able to read these stuff) */
node = new_kbnode( pkt );
c->list = node;
return 1;
}
else if( !c->list )
return 0; /* oops (invalid packet sequence)*/
else if( !c->list->pkt )
BUG(); /* so nicht */
/* add a new signature node id at the end */
node = new_kbnode( pkt );
add_kbnode( c->list, 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_DSA
|| 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, NULL );
}
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);
md_enable( c->mfx.md, DIGEST_ALGO_MD5 );
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 int
proc_compressed_cb( IOBUF a, void *info )
{
return proc_signature_packets( a, ((CTX)info)->signed_data );
}
static int
proc_encrypt_cb( IOBUF a, void *info )
{
return proc_encryption_packets( a );
}
static void
proc_compressed( CTX c, PACKET *pkt )
{
PKT_compressed *zd = pkt->pkt.compressed;
int rc;
/*printf("zip: compressed data packet\n");*/
if( c->sigs_only )
rc = handle_compressed( zd, proc_compressed_cb, c );
else if( c->encrypt_only )
rc = handle_compressed( zd, proc_encrypt_cb, c );
else
rc = handle_compressed( zd, NULL, NULL );
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;
algo = digest_algo_from_sig( sig );
if( !algo )
return G10ERR_PUBKEY_ALGO;
if( (rc=check_digest_algo(algo)) )
return rc;
if( sig->sig_class == 0x00 ) {
if( c->mfx.md )
md = md_copy( c->mfx.md );
else /* detached signature */
md = md_open( 0, 0 ); /* signature_check() will enable the md*/
}
else if( sig->sig_class == 0x01 ) {
/* how do we know that we have to hash the (already hashed) text
* in canonical mode ??? (calculating both modes???) */
if( c->mfx.md )
md = md_copy( c->mfx.md );
else /* detached signature */
md = md_open( 0, 0 ); /* signature_check() will enable the md*/
}
else if( (sig->sig_class&~3) == 0x10
|| sig->sig_class == 0x20
|| sig->sig_class == 0x30 ) { /* classes 0x10..0x13,0x20,0x30 */
if( c->list->pkt->pkttype == PKT_PUBLIC_CERT ) {
#if 0
KBNODE n1;
if( sig->sig_class == 0x20 ) {
md = md_open( algo, 0 );
hash_public_cert( md, c->list->pkt->pkt.public_cert );
}
else if( (n1=find_prev_kbnode( c->list, node, PKT_USER_ID )) ) {
md = md_open( algo, 0 );
hash_public_cert( md, c->list->pkt->pkt.public_cert );
if( sig->sig_class != 0x20 )
md_write( md, n1->pkt->pkt.user_id->name,
n1->pkt->pkt.user_id->len);
}
else {
log_error("invalid parent packet for sigclass %02x\n",
sig->sig_class);
return G10ERR_SIG_CLASS;
}
#endif
return check_key_signature( c->list, node, NULL );
}
else {
log_error("invalid root packet for sigclass %02x\n",
sig->sig_class);
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 )
BUG();
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,
opt.with_colons );
}
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 );
if( opt.with_colons ) {
printf("fpr::::::::");
for(i=0; i < n ; i++, p++ )
printf("%02X", *p );
putchar(':');
}
else {
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 )
{
int any=0;
if( !node )
;
else if( node->pkt->pkttype == PKT_PUBLIC_CERT ) {
PKT_public_cert *pkc = node->pkt->pkt.public_cert;
if( opt.with_colons ) {
u32 keyid[2];
keyid_from_pkc( pkc, keyid );
printf("pub::%u:%d:%08lX%08lX:%s:::",
/* fixme: add trust value here */
nbits_from_pkc( pkc ),
pkc->pubkey_algo,
(ulong)keyid[0],(ulong)keyid[1],
datestr_from_pkc( pkc )
/* fixme: add LID and ownertrust here */
);
}
else
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 ) );
/* and now list all userids with their signatures */
for( node = node->next; node; node = node->next ) {
if( any != 2 && node->pkt->pkttype == PKT_SIGNATURE ) {
if( !any ) {
if( node->pkt->pkt.signature->sig_class == 0x20 )
puts("[revoked]");
else
putchar('\n');
}
list_node(c, node );
any = 1;
}
else if( node->pkt->pkttype == PKT_USER_ID ) {
KBNODE n;
if( any ) {
if( opt.with_colons )
printf("uid::::::::");
else
printf( "uid%*s", 28, "" );
}
print_userid( node->pkt );
if( opt.with_colons )
putchar(':');
putchar('\n');
if( opt.fingerprint && !any )
print_fingerprint( pkc, NULL );
for( n=node->next; n; n = n->next ) {
if( n->pkt->pkttype == PKT_USER_ID )
break;
if( n->pkt->pkttype == PKT_SIGNATURE )
list_node(c, n );
}
any=2;
}
}
if( any != 2 )
printf("ERROR: no user id!\n");
}
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 ) );
/* and now list all userids */
while( (node = find_next_kbnode(node, PKT_USER_ID)) ) {
print_userid( node->pkt );
putchar('\n');
if( opt.fingerprint && !any )
print_fingerprint( NULL, skc );
any=1;
}
if( !any )
printf("ERROR: no user id!\n");
}
else if( node->pkt->pkttype == PKT_SIGNATURE ) {
PKT_signature *sig = node->pkt->pkt.signature;
int rc2=0;
size_t n;
char *p;
int sigrc = ' ';
if( !opt.list_sigs )
return;
if( sig->sig_class == 0x20 || sig->sig_class == 0x30 )
fputs("rev", stdout);
else
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;
}
}
if( opt.with_colons ) {
putchar(':');
if( sigrc != ' ' )
putchar(sigrc);
printf(":::%08lX%08lX:%s:::", (ulong)sig->keyid[0],
(ulong)sig->keyid[1], datestr_from_sig(sig));
}
else
printf("%c %08lX %s ",
sigrc, (ulong)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, opt.with_colons );
m_free(p);
}
if( opt.with_colons )
printf(":%02x:", sig->sig_class );
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 );
int rc = do_proc_packets( c, a );
m_free( c );
return rc;
}
int
proc_signature_packets( IOBUF a, STRLIST signedfiles )
{
CTX c = m_alloc_clear( sizeof *c );
int rc;
c->sigs_only = 1;
c->signed_data = signedfiles;
rc = do_proc_packets( c, a );
m_free( c );
return rc;
}
int
proc_encryption_packets( IOBUF a )
{
CTX c = m_alloc_clear( sizeof *c );
int rc;
c->encrypt_only = 1;
rc = do_proc_packets( c, a );
m_free( c );
return rc;
}
int
do_proc_packets( CTX c, IOBUF a )
{
PACKET *pkt = m_alloc( sizeof *pkt );
int rc=0;
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 if( c->sigs_only ) {
switch( pkt->pkttype ) {
case PKT_PUBLIC_CERT:
case PKT_SECRET_CERT:
case PKT_USER_ID:
case PKT_PUBKEY_ENC:
case PKT_ENCRYPTED:
rc = G10ERR_UNEXPECTED;
goto leave;
case PKT_SIGNATURE: newpkt = add_signature( 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;
}
}
else if( c->encrypt_only ) {
switch( pkt->pkttype ) {
case PKT_PUBLIC_CERT:
case PKT_SECRET_CERT:
case PKT_USER_ID:
rc = G10ERR_UNEXPECTED;
goto leave;
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;
}
}
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);
}
rc = 0;
leave:
release_list( c );
m_free(c->dek);
free_packet( pkt );
m_free( pkt );
free_md_filter_context( &c->mfx );
return rc;
}
static void
print_keyid( FILE *fp, u32 *keyid )
{
size_t n;
char *p = get_user_id( keyid, &n );
print_string( fp, p, n, opt.with_colons );
m_free(p);
}
static int
check_sig_and_print( CTX c, KBNODE node )
{
PKT_signature *sig = node->pkt->pkt.signature;
int rc;
rc = do_check_sig(c, node );
if( !rc || rc == G10ERR_BAD_SIGN ) {
char *p, *buf;
p = get_user_id_string( sig->keyid );
buf = m_alloc( 20 + strlen(p) );
sprintf(buf, "%lu %s", (ulong)sig->timestamp, p );
m_free(p);
if( (p=strchr(buf,'\n')) )
*p = 0; /* just in case ... */
write_status_text( rc? STATUS_BADSIG : STATUS_GOODSIG, buf );
m_free(buf);
log_info("%s signature from ", rc? "BAD":"Good");
print_keyid( stderr, sig->keyid );
putc('\n', stderr);
if( opt.batch )
g10_exit(1);
}
else {
write_status( STATUS_ERRSIG );
log_error("Can't check signature made by %08lX: %s\n",
(ulong)sig->keyid[1], g10_errstr(rc) );
}
return rc;
}
/****************
* 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 ) {
/* check all signatures */
if( !c->have_data ) {
free_md_filter_context( &c->mfx );
/* prepare to create all requested message digests */
c->mfx.md = md_open(0, 0);
/* fixme: why looking for the signature packet and not 1passpacket*/
for( n1 = node; (n1 = find_next_kbnode(n1, PKT_SIGNATURE )); ) {
md_enable( c->mfx.md,
digest_algo_from_sig(n1->pkt->pkt.signature));
}
/* ask for file and hash it */
if( c->sigs_only )
rc = hash_datafiles( c->mfx.md, c->signed_data,
n1->pkt->pkt.onepass_sig->sig_class == 0x01 );
else
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; (n1 = find_next_kbnode(n1, PKT_SIGNATURE )); )
check_sig_and_print( c, n1 );
}
else if( node->pkt->pkttype == PKT_SIGNATURE ) {
PKT_signature *sig = node->pkt->pkt.signature;
if( !c->have_data ) {
free_md_filter_context( &c->mfx );
c->mfx.md = md_open(digest_algo_from_sig(sig), 0);
if( c->sigs_only )
rc = hash_datafiles( c->mfx.md, c->signed_data,
sig->sig_class == 0x01 );
else
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;
}
}
else
log_info("old style signature\n");
check_sig_and_print( c, node );
}
else
log_error("proc_tree: invalid root packet\n");
}
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