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gnupg/g10/pipemode.c

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/* pipemode.c - pipemode handler
* Copyright (C) 1998, 1990, 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include "options.h"
#include "packet.h"
#include "errors.h"
#include "iobuf.h"
#include "keydb.h"
#include "memory.h"
#include "util.h"
#include "main.h"
#include "status.h"
#include "filter.h"
#define CONTROL_PACKET_SPACE 30
#define FAKED_LITERAL_PACKET_SPACE (9+2+2)
enum pipemode_state_e {
STX_init = 0,
STX_wait_operation,
STX_begin,
STX_text,
STX_detached_signature,
STX_detached_signature_wait_text,
STX_signed_data,
STX_wait_init
};
struct pipemode_context_s {
enum pipemode_state_e state;
int operation;
int stop;
int block_mode;
UnarmorPump unarmor_ctx;
};
static size_t
make_control ( byte *buf, int code, int operation )
{
const byte *sesmark;
size_t sesmarklen, n=0;;
sesmark = get_session_marker( &sesmarklen );
if ( sesmarklen > 20 )
BUG();
buf[n++] = 0xff; /* new format, type 63, 1 length byte */
n++; /* length will fixed below */
memcpy(buf+n, sesmark, sesmarklen ); n+= sesmarklen;
buf[n++] = CTRLPKT_PIPEMODE;
buf[n++] = code;
buf[n++] = operation;
buf[1] = n-2;
return n;
}
static int
pipemode_filter( void *opaque, int control,
IOBUF a, byte *buf, size_t *ret_len)
{
size_t size = *ret_len;
struct pipemode_context_s *stx = opaque;
int rc=0;
size_t n = 0;
int esc = 0;
if( control == IOBUFCTRL_UNDERFLOW ) {
*ret_len = 0;
/* reserve some space for one control packet */
if ( size <= CONTROL_PACKET_SPACE+FAKED_LITERAL_PACKET_SPACE )
BUG();
size -= CONTROL_PACKET_SPACE+FAKED_LITERAL_PACKET_SPACE;
if ( stx->block_mode ) {
/* reserve 2 bytes for the block length */
buf[n++] = 0;
buf[n++] = 0;
}
while ( n < size ) {
/* FIXME: we have to make sure that we have a large enough
* buffer for a control packet even after we already read
* something. The easest way to do this is probably by ungetting
* the control sequence and returning the buffer we have
* already assembled */
int c = iobuf_get (a);
if (c == -1) {
if ( stx->state != STX_init ) {
log_error ("EOF encountered at wrong state\n");
stx->stop = 1;
return -1;
}
break;
}
if ( esc ) {
switch (c) {
case '@':
if ( stx->state == STX_text ) {
buf[n++] = c;
break;
}
else if ( stx->state == STX_detached_signature ) {
esc = 0;
goto do_unarmor; /* not a very elegant solution */
}
else if ( stx->state == STX_detached_signature_wait_text) {
esc = 0;
break; /* just ignore it in this state */
}
log_error ("@@ not allowed in current state\n");
return -1;
case '<': /* begin of stream part */
if ( stx->state != STX_init ) {
log_error ("nested begin of stream\n");
stx->stop = 1;
return -1;
}
stx->state = STX_wait_operation;
stx->block_mode = 0;
unarmor_pump_release (stx->unarmor_ctx);
stx->unarmor_ctx = NULL;
break;
case '>': /* end of stream part */
if ( stx->state != STX_wait_init ) {
log_error ("invalid state for @>\n");
stx->stop = 1;
return -1;
}
stx->state = STX_init;
break;
case 'V': /* operation = verify */
case 'E': /* operation = encrypt */
case 'S': /* operation = sign */
case 'B': /* operation = detach sign */
case 'C': /* operation = clearsign */
case 'D': /* operation = decrypt */
if ( stx->state != STX_wait_operation ) {
log_error ("invalid state for operation code\n");
stx->stop = 1;
return -1;
}
stx->operation = c;
if ( stx->operation == 'B') {
stx->state = STX_detached_signature;
if ( !opt.no_armor )
stx->unarmor_ctx = unarmor_pump_new ();
}
else
stx->state = STX_begin;
n += make_control ( buf+n, 1, stx->operation );
/* must leave after a control packet */
goto leave;
case 't': /* plaintext text follows */
if ( stx->state == STX_detached_signature_wait_text )
stx->state = STX_detached_signature;
if ( stx->state == STX_detached_signature ) {
if ( stx->operation != 'B' ) {
log_error ("invalid operation for this state\n");
stx->stop = 1;
return -1;
}
stx->state = STX_signed_data;
n += make_control ( buf+n, 2, 'B' );
/* and now we fake a literal data packet much the same
* as in armor.c */
buf[n++] = 0xaf; /* old packet format, type 11,
var length */
buf[n++] = 0; /* set the length header */
buf[n++] = 6;
buf[n++] = 'b'; /* we ignore it anyway */
buf[n++] = 0; /* namelength */
memset(buf+n, 0, 4); /* timestamp */
n += 4;
/* and return now so that we are sure to have
* more space in the bufer for the next control
* packet */
stx->block_mode = 1;
goto leave2;
}
else {
log_error ("invalid state for @t\n");
stx->stop = 1;
return -1;
}
break;
case '.': /* ready */
if ( stx->state == STX_signed_data ) {
if (stx->block_mode) {
buf[0] = (n-2) >> 8;
buf[1] = (n-2);
if ( buf[0] || buf[1] ) {
/* end of blocks marker */
buf[n++] = 0;
buf[n++] = 0;
}
stx->block_mode = 0;
}
n += make_control ( buf+n, 3, 'B' );
}
else {
log_error ("invalid state for @.\n");
stx->stop = 1;
return -1;
}
stx->state = STX_wait_init;
goto leave;
default:
log_error ("invalid escape sequence 0x%02x in stream\n",
c);
stx->stop = 1;
return -1;
}
esc = 0;
}
else if (c == '@')
esc = 1;
else if (stx->unarmor_ctx) {
do_unarmor: /* used to handle a @@ */
c = unarmor_pump (stx->unarmor_ctx, c);
if ( !(c & ~255) )
buf[n++] = c;
else if ( c < 0 ) {
/* end of armor or error - we don't care becuase
the armor can be modified anyway. The unarmored
stuff should stand for itself. */
unarmor_pump_release (stx->unarmor_ctx);
stx->unarmor_ctx = NULL;
stx->state = STX_detached_signature_wait_text;
}
}
else if (stx->state == STX_detached_signature_wait_text)
; /* just wait */
else
buf[n++] = c;
}
leave:
if ( !n ) {
stx->stop = 1;
rc = -1; /* eof */
}
if ( stx->block_mode ) {
/* fixup the block length */
buf[0] = (n-2) >> 8;
buf[1] = (n-2);
}
leave2:
/*log_hexdump ("pipemode:", buf, n );*/
*ret_len = n;
}
else if( control == IOBUFCTRL_DESC )
*(char**)buf = "pipemode_filter";
return rc;
}
void
run_in_pipemode(void)
{
IOBUF fp;
armor_filter_context_t afx;
struct pipemode_context_s stx;
int rc;
memset( &afx, 0, sizeof afx);
memset( &stx, 0, sizeof stx);
fp = iobuf_open("-");
iobuf_push_filter (fp, pipemode_filter, &stx );
do {
write_status (STATUS_BEGIN_STREAM);
rc = proc_packets( NULL, fp );
write_status (STATUS_END_STREAM);
} while ( !stx.stop );
}
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