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Code Activity
gnupg/g10/build-packet.c
David Shaw 7997bba7a9 fix off-by-one in building attribute subpackets 
change default compression to 1
add ask-sig-expire and ask-cert-expire (--expert was getting absurdly
overloaded)
permit v3 subkeys
use --expert to protect adding multiple photo ids and adding photos to a
v3 key
2002-01-06 03:52:14 +00:00

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/* build-packet.c - assemble packets and write them
* Copyright (C) 1998, 1999, 2000, 2001 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_mdc( IOBUF out, PKT_mdc *mdc );
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_MDC:
rc = do_mdc( out, pkt->pkt.mdc );
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)*/
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.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 )
{
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, 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 );
n = ed->len ? (ed->len + ed->extralen) : 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_mdc( IOBUF out, PKT_mdc *mdc )
{
/* This packet requires a fixed header encoding */
iobuf_put( out, 0xd3 ); /* packet ID and 1 byte length */
iobuf_put( out, 0x14 ); /* length = 20 */
if( iobuf_write( out, mdc->hash, sizeof(mdc->hash) ) )
return G10ERR_WRITE_FILE;
return 0;
}
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;
}
/****************
* Find a subpacket of type REQTYPE in AREA and a return a pointer
* to the first byte of that subpacket data.
* And return the length of the packet in RET_N and the number of
* header bytes in RET_HLEN (length header and type byte).
*/
static byte *
find_subpkt (subpktarea_t *area, sigsubpkttype_t reqtype,
size_t *ret_hlen, size_t *ret_n )
{
byte *buffer;
int buflen;
sigsubpkttype_t type;
byte *bufstart;
size_t n;
if( !area )
return NULL;
buflen = area->len;
buffer = area->data;
for(;;) {
if( !buflen )
return NULL; /* end of packets; not found */
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++;
n--;
if( n > buflen )
break;
if( ret_hlen )
*ret_hlen = buffer - bufstart;
if( ret_n )
*ret_n = n;
return buffer;
}
buffer += n; buflen -=n;
}
log_error("find_subpkt: buffer shorter than subpacket\n");
return NULL;
}
/****************
* 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;
if( type == SIGSUBPKT_NOTATION )
; /* we allow multiple packets */
else if (find_subpkt (sig->hashed, type, NULL, NULL) ) {
switch (type) {
case SIGSUBPKT_SIG_CREATED:
case SIGSUBPKT_PREF_SYM:
case SIGSUBPKT_PREF_HASH:
case SIGSUBPKT_PREF_COMPR:
case SIGSUBPKT_FEATURES:
case SIGSUBPKT_SIG_EXPIRE:
delete_sig_subpkt (sig->hashed, type);
break;
default:
log_bug("build_sig_packet: update of hashed type %d nyi\n", type);
}
}
else if (find_subpkt (sig->unhashed, type, NULL, NULL)) {
switch (type) {
case SIGSUBPKT_PRIV_VERIFY_CACHE:
case SIGSUBPKT_ISSUER:
delete_sig_subpkt (sig->unhashed, type);
break;
default:
log_bug("build_sig_packet: update of unhashed type %d nyi\n",type);
}
}
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_ISSUER:
case SIGSUBPKT_PRIV_VERIFY_CACHE: /*(obsolete)*/
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,int buflen,
const void *header,int 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 */
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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