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gnupg/g10/build-packet.c
Werner Koch 5dfd5a6dac * pkclist.c (do_we_trust_pre): Changed the wording of a warning. 
* encode.c (encode_simple,encode_crypt): Use new style CTB for
compressssed packets when using MDC.  We need to do this so that
concatenated messages are properly decrypted.  Old style
compression assumes that it is the last packet; given that we
can't determine the length in advance, the uncompressor does not
know where to start.  Actually we should use the new CTB always
but this would break PGP 2 compatibility.
* parse-packet.c (parse): Special treatment for new style CTB
compressed packets.

* build-packet.c (do_mdc): Removed. Was not used.
(do_encrypted_mdc): Count the version number and the MDC packet.
2002-08-30 16:34:13 +00:00

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/* build-packet.c - assemble packets and write them
* Copyright (C) 1998, 1999, 2000, 2001, 2002 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_key( IOBUF out, int ctb, PKT_public_key *pk );
static int do_secret_key( IOBUF out, int ctb, PKT_secret_key *pk );
static int do_symkey_enc( IOBUF out, int ctb, PKT_symkey_enc *enc );
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_encrypted_mdc( 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, int new_ctb );
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_sign_packet_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 new_ctb=0, rc=0, ctb;
int pkttype;
if( DBG_PACKET )
log_debug("build_packet() type=%d\n", pkt->pkttype );
assert( pkt->pkt.generic );
switch( (pkttype = pkt->pkttype) ) {
case PKT_OLD_COMMENT: pkttype = pkt->pkttype = PKT_COMMENT; break;
case PKT_PLAINTEXT: new_ctb = pkt->pkt.plaintext->new_ctb; break;
case PKT_ENCRYPTED:
case PKT_ENCRYPTED_MDC: new_ctb = pkt->pkt.encrypted->new_ctb; break;
case PKT_COMPRESSED:new_ctb = pkt->pkt.compressed->new_ctb; break;
case PKT_USER_ID:
if( pkt->pkt.user_id->attrib_data )
pkttype = PKT_ATTRIBUTE;
break;
default: break;
}
if( new_ctb || pkttype > 15 ) /* new format */
ctb = 0xc0 | (pkttype & 0x3f);
else
ctb = 0x80 | ((pkttype & 15)<<2);
switch( pkttype ) {
case PKT_ATTRIBUTE:
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_SUBKEY:
case PKT_PUBLIC_KEY:
rc = do_public_key( out, ctb, pkt->pkt.public_key );
break;
case PKT_SECRET_SUBKEY:
case PKT_SECRET_KEY:
rc = do_secret_key( out, ctb, pkt->pkt.secret_key );
break;
case PKT_SYMKEY_ENC:
rc = do_symkey_enc( out, ctb, pkt->pkt.symkey_enc );
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_ENCRYPTED_MDC:
rc = do_encrypted_mdc( 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:
break; /* ignore it (keyring.c does write it directly)*/
case PKT_MDC: /* we write it directly, so we should never see it here. */
default:
log_bug("invalid packet type in build_packet()\n");
break;
}
return rc;
}
/****************
* calculate the length of a packet described by PKT
*/
u32
calc_packet_length( PACKET *pkt )
{
u32 n=0;
int new_ctb = 0;
assert( pkt->pkt.generic );
switch( pkt->pkttype ) {
case PKT_PLAINTEXT:
n = calc_plaintext( pkt->pkt.plaintext );
new_ctb = pkt->pkt.plaintext->new_ctb;
break;
case PKT_ATTRIBUTE:
case PKT_USER_ID:
case PKT_COMMENT:
case PKT_PUBLIC_KEY:
case PKT_SECRET_KEY:
case PKT_SYMKEY_ENC:
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, new_ctb);
return n;
}
static void
write_fake_data( IOBUF out, MPI a )
{
if( a ) {
int i;
void *p;
p = mpi_get_opaque( a, &i );
iobuf_write( out, p, i );
}
}
static int
do_comment( IOBUF out, int ctb, PKT_comment *rem )
{
if( opt.sk_comments ) {
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 )
{
if( uid->attrib_data ) {
write_header(out, ctb, uid->attrib_len);
if( iobuf_write( out, uid->attrib_data, uid->attrib_len ) )
return G10ERR_WRITE_FILE;
}
else {
write_header(out, ctb, uid->len);
if( iobuf_write( out, uid->name, uid->len ) )
return G10ERR_WRITE_FILE;
}
return 0;
}
static int
do_public_key( IOBUF out, int ctb, PKT_public_key *pk )
{
int rc = 0;
int n, i;
IOBUF a = iobuf_temp();
if( !pk->version )
iobuf_put( a, 3 );
else
iobuf_put( a, pk->version );
write_32(a, pk->timestamp );
if( pk->version < 4 ) {
u16 ndays;
if( pk->expiredate )
ndays = (u16)((pk->expiredate - pk->timestamp) / 86400L);
else
ndays = 0;
write_16(a, ndays );
}
iobuf_put(a, pk->pubkey_algo );
n = pubkey_get_npkey( pk->pubkey_algo );
if( !n )
write_fake_data( a, pk->pkey[0] );
for(i=0; i < n; i++ )
mpi_write(a, pk->pkey[i] );
write_header2(out, ctb, iobuf_get_temp_length(a), pk->hdrbytes, 1 );
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
iobuf_close(a);
return rc;
}
/****************
* Make a hash value from the public key certificate
*/
void
hash_public_key( MD_HANDLE md, PKT_public_key *pk )
{
PACKET pkt;
int rc = 0;
int ctb;
ulong pktlen;
int c;
IOBUF a = iobuf_temp();
#if 0
FILE *fp = fopen("dump.pk", "a");
int i=0;
fprintf(fp, "\nHashing PK (v%d):\n", pk->version);
#endif
/* build the packet */
init_packet(&pkt);
pkt.pkttype = PKT_PUBLIC_KEY;
pkt.pkt.public_key = pk;
if( (rc = build_packet( a, &pkt )) )
log_fatal("build public_key for hashing failed: %s\n", g10_errstr(rc));
if( !(pk->version == 3 && pk->pubkey_algo == 16) ) {
/* skip the constructed header but don't do this for our very old
* v3 ElG keys */
ctb = iobuf_get_noeof(a);
pktlen = 0;
if( (ctb & 0x40) ) {
c = iobuf_get_noeof(a);
if( c < 192 )
pktlen = c;
else if( c < 224 ) {
pktlen = (c - 192) * 256;
c = iobuf_get_noeof(a);
pktlen += c + 192;
}
else if( c == 255 ) {
pktlen = iobuf_get_noeof(a) << 24;
pktlen |= iobuf_get_noeof(a) << 16;
pktlen |= iobuf_get_noeof(a) << 8;
pktlen |= iobuf_get_noeof(a);
}
}
else {
int lenbytes = ((ctb&3)==3)? 0 : (1<<(ctb & 3));
for( ; lenbytes; lenbytes-- ) {
pktlen <<= 8;
pktlen |= iobuf_get_noeof(a);
}
}
/* hash a header */
md_putc( md, 0x99 );
pktlen &= 0xffff; /* can't handle longer packets */
md_putc( md, pktlen >> 8 );
md_putc( md, pktlen & 0xff );
}
/* hash the packet body */
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_key( IOBUF out, int ctb, PKT_secret_key *sk )
{
int rc = 0;
int i, nskey, npkey;
IOBUF a = iobuf_temp(); /* build in a self-enlarging buffer */
/* Write the version number - if none is specified, use 3 */
if( !sk->version )
iobuf_put( a, 3 );
else
iobuf_put( a, sk->version );
write_32(a, sk->timestamp );
/* v3 needs the expiration time */
if( sk->version < 4 ) {
u16 ndays;
if( sk->expiredate )
ndays = (u16)((sk->expiredate - sk->timestamp) / 86400L);
else
ndays = 0;
write_16(a, ndays);
}
iobuf_put(a, sk->pubkey_algo );
/* get number of secret and public parameters. They are held in
one array first the public ones, then the secret ones */
nskey = pubkey_get_nskey( sk->pubkey_algo );
npkey = pubkey_get_npkey( sk->pubkey_algo );
/* If we don't have any public parameters - which is the case if
we don't know the algorithm used - the parameters are stored as
one blob in a faked (opaque) MPI */
if( !npkey ) {
write_fake_data( a, sk->skey[0] );
goto leave;
}
assert( npkey < nskey );
/* Writing the public parameters is easy */
for(i=0; i < npkey; i++ )
mpi_write(a, sk->skey[i] );
/* build the header for protected (encrypted) secret parameters */
if( sk->is_protected ) {
if( is_RSA(sk->pubkey_algo) && sk->version < 4
&& !sk->protect.s2k.mode ) {
/* the simple rfc1991 (v3) way */
iobuf_put(a, sk->protect.algo );
iobuf_write(a, sk->protect.iv, sk->protect.ivlen );
}
else {
/* OpenPGP protection according to rfc2440 */
iobuf_put(a, sk->protect.sha1chk? 0xfe : 0xff );
iobuf_put(a, sk->protect.algo );
if( sk->protect.s2k.mode >= 1000 ) {
/* These modes are not possible in OpenPGP, we use them
to implement our extesnsions, 101 can ve views as a
private/experimental extension (this is not
specified in rfc2440 but the same scheme is used
for all other algorithm identifiers) */
iobuf_put(a, 101 );
iobuf_put(a, sk->protect.s2k.hash_algo );
iobuf_write(a, "GNU", 3 );
iobuf_put(a, sk->protect.s2k.mode - 1000 );
}
else {
iobuf_put(a, sk->protect.s2k.mode );
iobuf_put(a, sk->protect.s2k.hash_algo );
}
if( sk->protect.s2k.mode == 1
|| sk->protect.s2k.mode == 3 )
iobuf_write(a, sk->protect.s2k.salt, 8 );
if( sk->protect.s2k.mode == 3 )
iobuf_put(a, sk->protect.s2k.count );
/* For out special mode 1001 we do not need an IV */
if( sk->protect.s2k.mode != 1001 )
iobuf_write(a, sk->protect.iv, sk->protect.ivlen );
}
}
else
iobuf_put(a, 0 );
if( sk->protect.s2k.mode == 1001 )
; /* GnuPG extension - don't write a secret key at all */
else if( sk->is_protected && sk->version >= 4 ) {
/* The secret key is protected - write it out as it is */
byte *p;
assert( mpi_is_opaque( sk->skey[npkey] ) );
p = mpi_get_opaque( sk->skey[npkey], &i );
iobuf_write(a, p, i );
}
else {
/* v3 way - same code for protected and non- protected key */
for( ; i < nskey; i++ )
mpi_write(a, sk->skey[i] );
write_16(a, sk->csum );
}
leave:
/* Build the header of the packet - which we must do after writing all
the other stuff, so that we know the length of the packet */
write_header2(out, ctb, iobuf_get_temp_length(a), sk->hdrbytes, 1 );
/* And finally write it out the real stream */
if( iobuf_write_temp( out, a ) )
rc = G10ERR_WRITE_FILE;
iobuf_close(a); /* close the remporary buffer */
return rc;
}
static int
do_symkey_enc( IOBUF out, int ctb, PKT_symkey_enc *enc )
{
int rc = 0;
IOBUF a = iobuf_temp();
assert( enc->version == 4 );
switch( enc->s2k.mode ) {
case 0: case 1: case 3: break;
default: log_bug("do_symkey_enc: s2k=%d\n", enc->s2k.mode );
}
iobuf_put( a, enc->version );
iobuf_put( a, enc->cipher_algo );
iobuf_put( a, enc->s2k.mode );
iobuf_put( a, enc->s2k.hash_algo );
if( enc->s2k.mode == 1 || enc->s2k.mode == 3 ) {
iobuf_write(a, enc->s2k.salt, 8 );
if( enc->s2k.mode == 3 )
iobuf_put(a, enc->s2k.count);
}
if( enc->seskeylen )
iobuf_write(a, enc->seskey, enc->seskeylen );
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
do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc )
{
int rc = 0;
int n, i;
IOBUF a = iobuf_temp();
write_version( a, ctb );
if( enc->throw_keyid ) {
write_32(a, 0 ); /* don't tell Eve who can decrypt the message */
write_32(a, 0 );
}
else {
write_32(a, enc->keyid[0] );
write_32(a, enc->keyid[1] );
}
iobuf_put(a,enc->pubkey_algo );
n = pubkey_get_nenc( enc->pubkey_algo );
if( !n )
write_fake_data( a, enc->data[0] );
for(i=0; i < n; i++ )
mpi_write(a, enc->data[i] );
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 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 i, rc = 0;
u32 n;
byte buf[1000]; /* this buffer has the plaintext! */
int nbytes;
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( (nbytes=iobuf_read(pt->buf, buf, 1000)) != -1 ) {
if( iobuf_write(out, buf, nbytes) == -1 ) {
rc = G10ERR_WRITE_FILE;
break;
}
n += nbytes;
}
memset(buf,0,1000); /* at least burn the buffer */
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 + ed->extralen) : 0;
write_header(out, ctb, n );
/* This is all. The caller has to write the real data */
return rc;
}
static int
do_encrypted_mdc( IOBUF out, int ctb, PKT_encrypted *ed )
{
int rc = 0;
u32 n;
assert( ed->mdc_method );
/* Take version number and the following MDC packet in account. */
n = ed->len ? (ed->len + ed->extralen + 1 + 22) : 0;
write_header(out, ctb, n );
iobuf_put(out, 1 ); /* version */
/* 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 for tyhe
sake of PGP 2 compatibility. However if the new_ctb flag was
set, CTB is already formatted as new style and write_header2
does create a partial length encoding using new the new
style. */
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;
}
/****************
* Delete all subpackets of type REQTYPE and return a bool whether a packet
* was deleted.
*/
int
delete_sig_subpkt (subpktarea_t *area, sigsubpkttype_t reqtype )
{
int buflen;
sigsubpkttype_t type;
byte *buffer, *bufstart;
size_t n;
size_t unused = 0;
int okay = 0;
if( !area )
return 0;
buflen = area->len;
buffer = area->data;
for(;;) {
if( !buflen ) {
okay = 1;
break;
}
bufstart = buffer;
n = *buffer++; buflen--;
if( n == 255 ) {
if( buflen < 4 )
break;
n = (buffer[0] << 24) | (buffer[1] << 16)
| (buffer[2] << 8) | buffer[3];
buffer += 4;
buflen -= 4;
}
else if( n >= 192 ) {
if( buflen < 2 )
break;
n = (( n - 192 ) << 8) + *buffer + 192;
buffer++;
buflen--;
}
if( buflen < n )
break;
type = *buffer & 0x7f;
if( type == reqtype ) {
buffer++;
buflen--;
n--;
if( n > buflen )
break;
buffer += n; /* point to next subpkt */
buflen -= n;
memmove (bufstart, buffer, buflen); /* shift */
unused += buffer - bufstart;
buffer = bufstart;
}
else {
buffer += n; buflen -=n;
}
}
if (!okay)
log_error ("delete_subpkt: buffer shorter than subpacket\n");
assert (unused <= area->len);
area->len -= unused;
return !!unused;
}
/****************
* Create or update a signature subpacket for SIG of TYPE. This
* functions knows where to put the data (hashed or unhashed). The
* function may move data from the unhashed part to the hashed one.
* Note: All pointers into sig->[un]hashed (e.g. returned by
* parse_sig_subpkt) are not valid after a call to this function. The
* data to put into the subpaket should be in a buffer with a length
* of buflen.
*/
void
build_sig_subpkt (PKT_signature *sig, sigsubpkttype_t type,
const byte *buffer, size_t buflen )
{
byte *p;
int critical, hashed;
subpktarea_t *oldarea, *newarea;
size_t nlen, n, n0;
critical = (type & SIGSUBPKT_FLAG_CRITICAL);
type &= ~SIGSUBPKT_FLAG_CRITICAL;
/* Sanity check buffer sizes */
if(parse_one_sig_subpkt(buffer,buflen,type)<0)
BUG();
switch(type)
{
case SIGSUBPKT_NOTATION:
case SIGSUBPKT_POLICY:
case SIGSUBPKT_REV_KEY:
/* we do allow multiple subpackets */
break;
default:
/* we don't allow multiple subpackets */
delete_sig_subpkt(sig->hashed,type);
delete_sig_subpkt(sig->unhashed,type);
break;
}
/* Any special magic that needs to be done for this type so the
packet doesn't need to be reparsed? */
switch(type)
{
case SIGSUBPKT_NOTATION:
sig->flags.notation=1;
break;
case SIGSUBPKT_POLICY:
sig->flags.policy_url=1;
break;
case SIGSUBPKT_EXPORTABLE:
if(buffer[0])
sig->flags.exportable=1;
else
sig->flags.exportable=0;
break;
case SIGSUBPKT_REVOCABLE:
if(buffer[0])
sig->flags.revocable=1;
else
sig->flags.revocable=0;
break;
default:
break;
}
if( (buflen+1) >= 8384 )
nlen = 5; /* write 5 byte length header */
else if( (buflen+1) >= 192 )
nlen = 2; /* write 2 byte length header */
else
nlen = 1; /* just a 1 byte length header */
switch( type ) {
case SIGSUBPKT_PRIV_VERIFY_CACHE: /*(obsolete)*/
BUG();
break;
case SIGSUBPKT_ISSUER:
hashed = 0;
break;
default:
hashed = 1;
break;
}
if( critical )
type |= SIGSUBPKT_FLAG_CRITICAL;
oldarea = hashed? sig->hashed : sig->unhashed;
/* Calculate new size of the area and allocate */
n0 = oldarea? oldarea->len : 0;
n = n0 + nlen + 1 + buflen; /* length, type, buffer */
if (oldarea && n <= oldarea->size) { /* fits into the unused space */
newarea = oldarea;
/*log_debug ("updating area for type %d\n", type );*/
}
else if (oldarea) {
newarea = m_realloc (oldarea, sizeof (*newarea) + n - 1);
newarea->size = n;
/*log_debug ("reallocating area for type %d\n", type );*/
}
else {
newarea = m_alloc (sizeof (*newarea) + n - 1);
newarea->size = n;
/*log_debug ("allocating area for type %d\n", type );*/
}
newarea->len = n;
p = newarea->data + n0;
if (nlen == 5) {
*p++ = 255;
*p++ = (buflen+1) >> 24;
*p++ = (buflen+1) >> 16;
*p++ = (buflen+1) >> 8;
*p++ = (buflen+1);
*p++ = type;
memcpy (p, buffer, buflen);
}
else if (nlen == 2) {
*p++ = (buflen+1-192) / 256 + 192;
*p++ = (buflen+1-192) % 256;
*p++ = type;
memcpy (p, buffer, buflen);
}
else {
*p++ = buflen+1;
*p++ = type;
memcpy (p, buffer, buflen);
}
if (hashed)
sig->hashed = newarea;
else
sig->unhashed = newarea;
}
/****************
* Put all the required stuff from SIG into subpackets of sig.
* Hmmm, should we delete those subpackets which are in a wrong area?
*/
void
build_sig_subpkt_from_sig( PKT_signature *sig )
{
u32 u;
byte buf[8];
u = sig->keyid[0];
buf[0] = (u >> 24) & 0xff;
buf[1] = (u >> 16) & 0xff;
buf[2] = (u >> 8) & 0xff;
buf[3] = u & 0xff;
u = sig->keyid[1];
buf[4] = (u >> 24) & 0xff;
buf[5] = (u >> 16) & 0xff;
buf[6] = (u >> 8) & 0xff;
buf[7] = u & 0xff;
build_sig_subpkt( sig, SIGSUBPKT_ISSUER, buf, 8 );
u = sig->timestamp;
buf[0] = (u >> 24) & 0xff;
buf[1] = (u >> 16) & 0xff;
buf[2] = (u >> 8) & 0xff;
buf[3] = u & 0xff;
build_sig_subpkt( sig, SIGSUBPKT_SIG_CREATED, buf, 4 );
if(sig->expiredate)
{
u = sig->expiredate-sig->timestamp;
buf[0] = (u >> 24) & 0xff;
buf[1] = (u >> 16) & 0xff;
buf[2] = (u >> 8) & 0xff;
buf[3] = u & 0xff;
/* Mark this CRITICAL, so if any implementation doesn't
understand sigs that can expire, it'll just disregard this
sig altogether. */
build_sig_subpkt( sig, SIGSUBPKT_SIG_EXPIRE | SIGSUBPKT_FLAG_CRITICAL,
buf, 4 );
}
}
void
build_attribute_subpkt(PKT_user_id *uid,byte type,
const void *buf,u32 buflen,
const void *header,u32 headerlen)
{
byte *attrib;
int idx;
if(1+headerlen+buflen>8383)
idx=5;
else if(1+headerlen+buflen>191)
idx=2;
else
idx=1;
/* realloc uid->attrib_data to the right size */
uid->attrib_data=m_realloc(uid->attrib_data,
uid->attrib_len+idx+1+headerlen+buflen);
attrib=&uid->attrib_data[uid->attrib_len];
if(idx==5)
{
attrib[0]=255;
attrib[1]=(1+headerlen+buflen) >> 24;
attrib[2]=(1+headerlen+buflen) >> 16;
attrib[3]=(1+headerlen+buflen) >> 8;
attrib[4]=1+headerlen+buflen;
}
else if(idx==2)
{
attrib[0]=(1+headerlen+buflen-192) / 256 + 192;
attrib[1]=(1+headerlen+buflen-192) % 256;
}
else
attrib[0]=1+headerlen+buflen; /* Good luck finding a JPEG this small! */
attrib[idx++]=type;
/* Tack on our data at the end */
if(headerlen>0)
memcpy(&attrib[idx],header,headerlen);
memcpy(&attrib[idx+headerlen],buf,buflen);
uid->attrib_len+=idx+headerlen+buflen;
}
static int
do_signature( IOBUF out, int ctb, PKT_signature *sig )
{
int rc = 0;
int n, i;
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 ) {
size_t nn;
/* timestamp and keyid must have been packed into the
* subpackets prior to the call of this function, because
* these subpackets are hashed */
nn = sig->hashed? sig->hashed->len : 0;
write_16(a, nn);
if( nn )
iobuf_write( a, sig->hashed->data, nn );
nn = sig->unhashed? sig->unhashed->len : 0;
write_16(a, nn);
if( nn )
iobuf_write( a, sig->unhashed->data, nn );
}
iobuf_put(a, sig->digest_start[0] );
iobuf_put(a, sig->digest_start[1] );
n = pubkey_get_nsig( sig->pubkey_algo );
if( !n )
write_fake_data( a, sig->data[0] );
for(i=0; i < n; i++ )
mpi_write(a, sig->data[i] );
if( is_RSA(sig->pubkey_algo) && sig->version < 4 )
write_sign_packet_header(out, ctb, iobuf_get_temp_length(a) );
else
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
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, int new_ctb )
{
if( !len )
return 1; /* only the ctb */
if( new_ctb ) {
if( len < 192 )
return 2;
if( len < 8384 )
return 3;
else
return 6;
}
if( len < 256 )
return 2;
if( len < 65536 )
return 3;
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 );
}
static int
write_sign_packet_header( IOBUF out, int ctb, u32 len )
{
/* work around a bug in the pgp read function for signature packets,
* which are not correctly coded and silently assume at some
* point 2 byte length headers.*/
iobuf_put(out, 0x89 );
iobuf_put(out, len >> 8 );
return iobuf_put(out, len ) == -1 ? -1:0;
}
/****************
* if HDRLEN is > 0, try to build a header of this length.
* we need this, so that 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 ) {
iobuf_set_partial_block_mode(out, 512 );
}
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 {
if( iobuf_put( out, 0xff ) )
return -1;
if( iobuf_put( out, (len >> 24)&0xff ) )
return -1;
if( iobuf_put( out, (len >> 16)&0xff ) )
return -1;
if( iobuf_put( out, (len >> 8)&0xff ) )
return -1;
if( iobuf_put( out, len & 0xff ) )
return -1;
}
}
return 0;
}
static int
write_version( IOBUF out, int ctb )
{
if( iobuf_put( out, 3 ) )
return -1;
return 0;
}
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