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gnupg/g10/build-packet.c

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/* build-packet.c - assemble packets and write them
* 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 "errors.h"
#include "iobuf.h"
#include "mpi.h"
#include "util.h"
#include "cipher.h"
#include "memory.h"
#include "options.h"
static int do_comment( IOBUF out, int ctb, PKT_comment *rem );
static int do_user_id( IOBUF out, int ctb, PKT_user_id *uid );
static int do_public_cert( IOBUF out, int ctb, PKT_public_cert *pk );
static int do_secret_cert( IOBUF out, int ctb, PKT_secret_cert *pk );
static int do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc );
static u32 calc_plaintext( PKT_plaintext *pt );
static int do_plaintext( IOBUF out, int ctb, PKT_plaintext *pt );
static int do_encrypted( IOBUF out, int ctb, PKT_encrypted *ed );
static int do_compressed( IOBUF out, int ctb, PKT_compressed *cd );
static int do_signature( IOBUF out, int ctb, PKT_signature *sig );
static int do_onepass_sig( IOBUF out, int ctb, PKT_onepass_sig *ops );
static int calc_header_length( u32 len );
static int write_16(IOBUF inp, u16 a);
static int write_32(IOBUF inp, u32 a);
static int write_header( IOBUF out, int ctb, u32 len );
static int write_header2( IOBUF out, int ctb, u32 len, int hdrlen, int blkmode );
static int write_new_header( IOBUF out, int ctb, u32 len, int hdrlen );
static int write_version( IOBUF out, int ctb );
/****************
* Build a packet and write it to INP
* Returns: 0 := okay
* >0 := error
* Note: Caller must free the packet
*/
int
build_packet( IOBUF out, PACKET *pkt )
{
int rc=0, ctb;
if( DBG_PACKET )
log_debug("build_packet() type=%d\n", pkt->pkttype );
assert( pkt->pkt.generic );
if( pkt->pkttype > 15 ) /* new format */
ctb = 0xc0 | (pkt->pkttype & 0x3f);
else
ctb = 0x80 | ((pkt->pkttype & 15)<<2);
switch( pkt->pkttype ) {
case PKT_USER_ID:
rc = do_user_id( out, ctb, pkt->pkt.user_id );
break;
case PKT_COMMENT:
rc = do_comment( out, ctb, pkt->pkt.comment );
break;
case PKT_PUBLIC_CERT:
rc = do_public_cert( out, ctb, pkt->pkt.public_cert );
break;
case PKT_SECRET_CERT:
rc = do_secret_cert( out, ctb, pkt->pkt.secret_cert );
break;
case PKT_PUBKEY_ENC:
rc = do_pubkey_enc( out, ctb, pkt->pkt.pubkey_enc );
break;
case PKT_PLAINTEXT:
rc = do_plaintext( out, ctb, pkt->pkt.plaintext );
break;
case PKT_ENCRYPTED:
rc = do_encrypted( out, ctb, pkt->pkt.encrypted );
break;
case PKT_COMPRESSED:
rc = do_compressed( out, ctb, pkt->pkt.compressed );
break;
case PKT_SIGNATURE:
rc = do_signature( out, ctb, pkt->pkt.signature );
break;
case PKT_ONEPASS_SIG:
rc = do_onepass_sig( out, ctb, pkt->pkt.onepass_sig );
break;
case PKT_RING_TRUST:
default:
log_bug("invalid packet type in build_packet()");
break;
}
return rc;
}
/****************
* calculate the length of a packet described by PKT
*/
u32
calc_packet_length( PACKET *pkt )
{
u32 n=0;
assert( pkt->pkt.generic );
switch( pkt->pkttype ) {
case PKT_PLAINTEXT:
n = calc_plaintext( pkt->pkt.plaintext );
break;
case PKT_USER_ID:
case PKT_COMMENT:
case PKT_PUBLIC_CERT:
case PKT_SECRET_CERT:
case PKT_PUBKEY_ENC:
case PKT_ENCRYPTED:
case PKT_SIGNATURE:
case PKT_ONEPASS_SIG:
case PKT_RING_TRUST:
case PKT_COMPRESSED:
default:
log_bug("invalid packet type in calc_packet_length()");
break;
}
n += calc_header_length(n);
return n;
}
static int
do_comment( IOBUF out, int ctb, PKT_comment *rem )
{
if( !opt.no_comment ) {
write_header(out, ctb, rem->len);
if( iobuf_write( out, rem->data, rem->len ) )
return G10ERR_WRITE_FILE;
}
return 0;
}
static int
do_user_id( IOBUF out, int ctb, PKT_user_id *uid )
{
write_header(out, ctb, uid->len);
if( iobuf_write( out, uid->name, uid->len ) )
return G10ERR_WRITE_FILE;
return 0;
}
static int
do_public_cert( IOBUF out, int ctb, PKT_public_cert *pkc )
{
int rc = 0;
IOBUF a = iobuf_temp();
if( !pkc->version )
iobuf_put( a, 3 );
else
iobuf_put( a, pkc->version );
write_32(a, pkc->timestamp );
if( pkc->version < 4 )
write_16(a, pkc->valid_days );
iobuf_put(a, pkc->pubkey_algo );
if( pkc->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_write(a, pkc->d.elg.p );
mpi_write(a, pkc->d.elg.g );
mpi_write(a, pkc->d.elg.y );
}
else if( pkc->pubkey_algo == PUBKEY_ALGO_DSA ) {
mpi_write(a, pkc->d.dsa.p );
mpi_write(a, pkc->d.dsa.q );
mpi_write(a, pkc->d.dsa.g );
mpi_write(a, pkc->d.dsa.y );
}
else if( pkc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_write(a, pkc->d.rsa.rsa_n );
mpi_write(a, pkc->d.rsa.rsa_e );
}
else {
rc = G10ERR_PUBKEY_ALGO;
goto leave;
}
write_header2(out, ctb, iobuf_get_temp_length(a), pkc->hdrbytes, 1 );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
leave:
iobuf_close(a);
return rc;
}
/****************
* Make a hash value from the public key certificate
*/
void
hash_public_cert( MD_HANDLE md, PKT_public_cert *pkc )
{
PACKET pkt;
int rc = 0;
int c;
IOBUF a = iobuf_temp();
#if 0
FILE *fp = fopen("dump.pkc", "a");
int i=0;
fprintf(fp, "\nHashing PKC:\n");
#endif
/* build the packet */
init_packet(&pkt);
pkt.pkttype = PKT_PUBLIC_CERT;
pkt.pkt.public_cert = pkc;
if( (rc = build_packet( a, &pkt )) )
log_fatal("build public_cert for hashing failed: %s\n", g10_errstr(rc));
while( (c=iobuf_get(a)) != -1 ) {
#if 0
fprintf( fp," %02x", c );
if( (++i == 24) ) {
putc('\n', fp);
i=0;
}
#endif
md_putc( md, c );
}
#if 0
putc('\n', fp);
fclose(fp);
#endif
iobuf_cancel(a);
}
static int
do_secret_cert( IOBUF out, int ctb, PKT_secret_cert *skc )
{
int rc = 0;
IOBUF a = iobuf_temp();
if( !skc->version )
iobuf_put( a, 3 );
else
iobuf_put( a, skc->version );
write_32(a, skc->timestamp );
if( skc->version < 4 )
write_16(a, skc->valid_days );
iobuf_put(a, skc->pubkey_algo );
if( skc->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_write(a, skc->d.elg.p );
mpi_write(a, skc->d.elg.g );
mpi_write(a, skc->d.elg.y );
if( skc->d.elg.is_protected ) {
iobuf_put(a, 0xff );
iobuf_put(a, skc->d.elg.protect.algo );
iobuf_put(a, skc->d.elg.protect.s2k );
iobuf_put(a, skc->d.elg.protect.hash );
if( skc->d.elg.protect.s2k == 1
|| skc->d.elg.protect.s2k == 3 )
iobuf_write(a, skc->d.elg.protect.salt, 8 );
if( skc->d.elg.protect.s2k == 3 )
iobuf_put(a, skc->d.elg.protect.count );
iobuf_write(a, skc->d.elg.protect.iv, 8 );
}
else
iobuf_put(a, 0 );
mpi_write(a, skc->d.elg.x );
write_16(a, skc->d.elg.csum );
}
else if( skc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_write(a, skc->d.rsa.rsa_n );
mpi_write(a, skc->d.rsa.rsa_e );
if( skc->d.rsa.is_protected ) {
assert( skc->d.rsa.protect_algo == CIPHER_ALGO_BLOWFISH );
iobuf_put(a, skc->d.rsa.protect_algo );
iobuf_write(a, skc->d.rsa.protect.blowfish.iv, 8 );
}
else
iobuf_put(a, 0 );
mpi_write(a, skc->d.rsa.rsa_d );
mpi_write(a, skc->d.rsa.rsa_p );
mpi_write(a, skc->d.rsa.rsa_q );
mpi_write(a, skc->d.rsa.rsa_u );
write_16(a, skc->d.rsa.csum );
}
else {
rc = G10ERR_PUBKEY_ALGO;
goto leave;
}
write_header2(out, ctb, iobuf_get_temp_length(a), skc->hdrbytes, 1 );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
leave:
iobuf_close(a);
return rc;
}
static int
do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc )
{
int rc = 0;
IOBUF a = iobuf_temp();
write_version( a, ctb );
write_32(a, enc->keyid[0] );
write_32(a, enc->keyid[1] );
iobuf_put(a,enc->pubkey_algo );
if( enc->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_write(a, enc->d.elg.a );
mpi_write(a, enc->d.elg.b );
}
else if( enc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_write(a, enc->d.rsa.rsa_integer );
}
else {
rc = G10ERR_PUBKEY_ALGO;
goto leave;
}
write_header(out, ctb, iobuf_get_temp_length(a) );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
leave:
iobuf_close(a);
return rc;
}
static u32
calc_plaintext( PKT_plaintext *pt )
{
return pt->len? (1 + 1 + pt->namelen + 4 + pt->len) : 0;
}
static int
do_plaintext( IOBUF out, int ctb, PKT_plaintext *pt )
{
int c, i, rc = 0;
u32 n;
write_header(out, ctb, calc_plaintext( pt ) );
iobuf_put(out, pt->mode );
iobuf_put(out, pt->namelen );
for(i=0; i < pt->namelen; i++ )
iobuf_put(out, pt->name[i] );
if( write_32(out, pt->timestamp ) )
rc = G10ERR_WRITE_FILE;
n = 0;
while( (c=iobuf_get(pt->buf)) != -1 ) {
if( iobuf_put(out, c) ) {
rc = G10ERR_WRITE_FILE;
break;
}
n++;
}
if( !pt->len )
iobuf_set_block_mode(out, 0 ); /* write end marker */
else if( n != pt->len )
log_error("do_plaintext(): wrote %lu bytes but expected %lu bytes\n",
(ulong)n, (ulong)pt->len );
return rc;
}
static int
do_encrypted( IOBUF out, int ctb, PKT_encrypted *ed )
{
int rc = 0;
u32 n;
n = ed->len ? (ed->len + 10) : 0;
write_header(out, ctb, n );
/* This is all. The caller has to write the real data */
return rc;
}
static int
do_compressed( IOBUF out, int ctb, PKT_compressed *cd )
{
int rc = 0;
/* we must use the old convention and don't use blockmode */
write_header2(out, ctb, 0, 0, 0 );
iobuf_put(out, cd->algorithm );
/* This is all. The caller has to write the real data */
return rc;
}
static int
do_signature( IOBUF out, int ctb, PKT_signature *sig )
{
int rc = 0;
IOBUF a = iobuf_temp();
if( !sig->version )
iobuf_put( a, 3 );
else
iobuf_put( a, sig->version );
if( sig->version < 4 )
iobuf_put(a, 5 ); /* constant */
iobuf_put(a, sig->sig_class );
if( sig->version < 4 ) {
write_32(a, sig->timestamp );
write_32(a, sig->keyid[0] );
write_32(a, sig->keyid[1] );
}
iobuf_put(a, sig->pubkey_algo );
iobuf_put(a, sig->digest_algo );
if( sig->version >= 4 ) {
/* fixme: write v4 subpackets here */
log_error("WARNING: note writing of v4 subpackets is not implemented\n");
}
iobuf_put(a, sig->digest_start[0] );
iobuf_put(a, sig->digest_start[1] );
if( sig->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_write(a, sig->d.elg.a );
mpi_write(a, sig->d.elg.b );
}
else if( sig->pubkey_algo == PUBKEY_ALGO_DSA ) {
mpi_write(a, sig->d.dsa.r );
mpi_write(a, sig->d.dsa.s );
}
else if( sig->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_write(a, sig->d.rsa.rsa_integer );
}
else {
rc = G10ERR_PUBKEY_ALGO;
goto leave;
}
write_header(out, ctb, iobuf_get_temp_length(a) );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
leave:
iobuf_close(a);
return rc;
}
static int
do_onepass_sig( IOBUF out, int ctb, PKT_onepass_sig *ops )
{
int rc = 0;
IOBUF a = iobuf_temp();
write_version( a, ctb );
iobuf_put(a, ops->sig_class );
iobuf_put(a, ops->digest_algo );
iobuf_put(a, ops->pubkey_algo );
write_32(a, ops->keyid[0] );
write_32(a, ops->keyid[1] );
iobuf_put(a, ops->last );
write_header(out, ctb, iobuf_get_temp_length(a) );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
iobuf_close(a);
return rc;
}
static int
write_16(IOBUF out, u16 a)
{
iobuf_put(out, a>>8);
if( iobuf_put(out,a) )
return -1;
return 0;
}
static int
write_32(IOBUF out, u32 a)
{
iobuf_put(out, a>> 24);
iobuf_put(out, a>> 16);
iobuf_put(out, a>> 8);
if( iobuf_put(out, a) )
return -1;
return 0;
}
/****************
* calculate the length of a header
*/
static int
calc_header_length( u32 len )
{
if( !len )
return 1; /* only the ctb */
else if( len < 256 )
return 2;
else if( len < 65536 )
return 3;
else
return 5;
}
/****************
* Write the CTB and the packet length
*/
static int
write_header( IOBUF out, int ctb, u32 len )
{
return write_header2( out, ctb, len, 0, 1 );
}
/****************
* if HDRLEN is > 0, try to build a header of this length.
* we need this, so hat we can hash packets without reading them again.
*/
static int
write_header2( IOBUF out, int ctb, u32 len, int hdrlen, int blkmode )
{
if( ctb & 0x40 )
return write_new_header( out, ctb, len, hdrlen );
if( hdrlen ) {
if( !len )
ctb |= 3;
else if( hdrlen == 2 && len < 256 )
;
else if( hdrlen == 3 && len < 65536 )
ctb |= 1;
else
ctb |= 2;
}
else {
if( !len )
ctb |= 3;
else if( len < 256 )
;
else if( len < 65536 )
ctb |= 1;
else
ctb |= 2;
}
if( iobuf_put(out, ctb ) )
return -1;
if( !len ) {
if( blkmode )
iobuf_set_block_mode(out, 8196 );
}
else {
if( ctb & 2 ) {
iobuf_put(out, len >> 24 );
iobuf_put(out, len >> 16 );
}
if( ctb & 3 )
iobuf_put(out, len >> 8 );
if( iobuf_put(out, len ) )
return -1;
}
return 0;
}
static int
write_new_header( IOBUF out, int ctb, u32 len, int hdrlen )
{
if( hdrlen )
log_bug("can't cope with hdrlen yet\n");
if( iobuf_put(out, ctb ) )
return -1;
if( !len ) {
log_bug("can't write partial headers yet\n");
}
else {
if( len < 192 ) {
if( iobuf_put(out, len ) )
return -1;
}
else if( len < 8384 ) {
len -= 192;
if( iobuf_put( out, (len / 256) + 192) )
return -1;
if( iobuf_put( out, (len % 256) ) )
return -1;
}
else
log_bug("need a partial header to code a length %lu\n", (ulong)len);
}
return 0;
}
static int
write_version( IOBUF out, int ctb )
{
if( iobuf_put( out, 3 ) )
return -1;
return 0;
}
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