security-and-privacy/gnupg
security-and-privacy
/
gnupg
mirror of git://git.gnupg.org/gnupg.git
1
0
Fork 0
Code Releases Activity
gnupg/g10/build-packet.c

514 lines
12 KiB
C
Raw Blame History

/* build-packet.c - assemble packets and write them
* 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 <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 blkmode );
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 );
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 )
{
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();
write_version( a, ctb );
write_32(a, pkc->timestamp );
write_16(a, pkc->valid_days );
iobuf_put(a, pkc->pubkey_algo );
if( pkc->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_encode(a, pkc->d.elg.p );
mpi_encode(a, pkc->d.elg.g );
mpi_encode(a, pkc->d.elg.y );
}
else if( pkc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_encode(a, pkc->d.rsa.rsa_n );
mpi_encode(a, pkc->d.rsa.rsa_e );
}
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_secret_cert( IOBUF out, int ctb, PKT_secret_cert *skc )
{
int rc = 0;
IOBUF a = iobuf_temp();
write_version( a, ctb );
write_32(a, skc->timestamp );
write_16(a, skc->valid_days );
iobuf_put(a, skc->pubkey_algo );
if( skc->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
mpi_encode(a, skc->d.elg.p );
mpi_encode(a, skc->d.elg.g );
mpi_encode(a, skc->d.elg.y );
iobuf_put(a, skc->d.elg.protect_algo );
skc->d.elg.calc_csum = 0;
if( skc->d.elg.protect_algo ) {
assert( skc->d.elg.is_protected == 1 );
assert( skc->d.elg.protect_algo == CIPHER_ALGO_BLOWFISH );
iobuf_write(a, skc->d.elg.protect.blowfish.iv, 8 );
mpi_write_csum(a, (byte*)skc->d.elg.x, &skc->d.elg.calc_csum );
}
else { /* not protected */
assert( !skc->d.elg.is_protected );
mpi_encode_csum(a, skc->d.elg.x, &skc->d.elg.calc_csum );
}
write_16(a, skc->d.elg.calc_csum );
}
else if( skc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_encode(a, skc->d.rsa.rsa_n );
mpi_encode(a, skc->d.rsa.rsa_e );
iobuf_put(a, skc->d.rsa.protect_algo );
skc->d.rsa.calc_csum = 0;
if( skc->d.rsa.protect_algo ) {
assert( skc->d.rsa.is_protected == 1 );
assert( skc->d.rsa.protect_algo == CIPHER_ALGO_BLOWFISH );
iobuf_write(a, skc->d.rsa.protect.blowfish.iv, 8 );
mpi_write_csum(a, (byte*)skc->d.rsa.rsa_d, &skc->d.rsa.calc_csum );
mpi_write_csum(a, (byte*)skc->d.rsa.rsa_p, &skc->d.rsa.calc_csum );
mpi_write_csum(a, (byte*)skc->d.rsa.rsa_q, &skc->d.rsa.calc_csum );
mpi_write_csum(a, (byte*)skc->d.rsa.rsa_u, &skc->d.rsa.calc_csum );
}
else { /* Not protected: You fool you! */
assert( !skc->d.rsa.is_protected );
mpi_encode_csum(a, skc->d.rsa.rsa_d, &skc->d.rsa.calc_csum );
mpi_encode_csum(a, skc->d.rsa.rsa_p, &skc->d.rsa.calc_csum );
mpi_encode_csum(a, skc->d.rsa.rsa_q, &skc->d.rsa.calc_csum );
mpi_encode_csum(a, skc->d.rsa.rsa_u, &skc->d.rsa.calc_csum );
}
write_16(a, skc->d.rsa.calc_csum );
}
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_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_encode(a, enc->d.elg.a );
mpi_encode(a, enc->d.elg.b );
}
else if( enc->pubkey_algo == PUBKEY_ALGO_RSA ) {
mpi_encode(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 );
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();
write_version( a, ctb );
iobuf_put(a, 5 ); /* constant */
iobuf_put(a, sig->sig_class );
write_32(a, sig->timestamp );
write_32(a, sig->keyid[0] );
write_32(a, sig->keyid[1] );
iobuf_put(a, sig->pubkey_algo );
if( sig->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
iobuf_put(a, sig->d.elg.digest_algo );
iobuf_put(a, sig->d.elg.digest_start[0] );
iobuf_put(a, sig->d.elg.digest_start[1] );
mpi_encode(a, sig->d.elg.a );
mpi_encode(a, sig->d.elg.b );
}
else if( sig->pubkey_algo == PUBKEY_ALGO_RSA ) {
iobuf_put(a, sig->d.rsa.digest_algo );
iobuf_put(a, sig->d.rsa.digest_start[0] );
iobuf_put(a, sig->d.rsa.digest_start[1] );
mpi_encode(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;
leave:
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, 1 );
}
static int
write_header2( IOBUF out, int ctb, u32 len, int blkmode )
{
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_version( IOBUF out, int ctb )
{
if( iobuf_put( out, 3 ) )
return -1;
return 0;
}
View Git Blame Copy Permalink