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See ChangeLog: Fri Jul 14 19:38:23 CEST 2000 Werner Koch

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This commit is contained in:
Werner Koch 2000-07-14 17:34:53 +00:00
parent d1648b4d7a
commit 92cd255508
104 changed files with 5871 additions and 1540 deletions
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49
g10/cipher.c
View file

@ -1,5 +1,5 @@
/* cipher.c - En-/De-ciphering filter
* Copyright (C) 1998,1999 Free Software Foundation, Inc.
* Copyright (C) 1998, 1999, 2000 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
@ -33,6 +33,7 @@
#include "packet.h"
#include "options.h"
#include "main.h"
#include "status.h"
#define MIN_PARTIAL_SIZE 512
@ -44,10 +45,18 @@ write_header( cipher_filter_context_t *cfx, IOBUF a )
PACKET pkt;
PKT_encrypted ed;
byte temp[18];
int blocksize;
unsigned nprefix;
int use_mdc = opt.force_mdc;
unsigned int blocksize;
unsigned int nprefix;
int rc;
int use_mdc = opt.force_mdc;
blocksize = gcry_cipher_get_algo_blklen( cfx->dek->algo );
if( blocksize < 8 || blocksize > 16 )
log_fatal("unsupported blocksize %u\n", blocksize );
if( blocksize != 8 )
use_mdc = 1; /* enable it for all modern ciphers */
if( opt.rfc2440 )
use_mdc = 0; /* override - rfc2440 does not know about MDC */
memset( &ed, 0, sizeof ed );
ed.len = cfx->datalen;
@ -55,18 +64,16 @@ write_header( cipher_filter_context_t *cfx, IOBUF a )
if( use_mdc ) {
ed.mdc_method = GCRY_MD_SHA1;
cfx->mdc_hash = gcry_md_open( GCRY_MD_SHA1, 0 );
/*should we check the function works, or is it better to provide
a flag which makes the function die itself ?? FIXME */
/*md_start_debug( cfx->mdc_hash, "mdccreat" );*/
if( !cfx->mdc_hash )
BUG();
if ( DBG_HASHING )
gcry_md_start_debug( cfx->mdc_hash, "creatmdc" );
}
init_packet( &pkt );
pkt.pkttype = use_mdc? PKT_ENCRYPTED_MDC : PKT_ENCRYPTED;
pkt.pkt.encrypted = &ed;
if( build_packet( a, &pkt ))
log_bug("build_packet(ENCR_DATA) failed\n");
blocksize = gcry_cipher_get_algo_blklen( cfx->dek->algo );
if( blocksize < 8 || blocksize > 16 )
log_fatal("unsupported blocksize %d\n", blocksize );
nprefix = blocksize;
gcry_randomize( temp, nprefix, GCRY_STRONG_RANDOM );
temp[nprefix] = temp[nprefix-2];
@ -75,7 +82,7 @@ write_header( cipher_filter_context_t *cfx, IOBUF a )
if( !(cfx->cipher_hd = gcry_cipher_open( cfx->dek->algo,
GCRY_CIPHER_MODE_CFB,
GCRY_CIPHER_SECURE
| (cfx->dek->algo >= 100 ?
| ((use_mdc || cfx->dek->algo >= 100) ?
0 : GCRY_CIPHER_ENABLE_SYNC)))
) {
/* we should never get an error here cause we already checked, that
@ -83,6 +90,7 @@ write_header( cipher_filter_context_t *cfx, IOBUF a )
BUG();
}
/* log_hexdump( "thekey", cfx->dek->key, cfx->dek->keylen );*/
rc = gcry_cipher_setkey( cfx->cipher_hd, cfx->dek->key, cfx->dek->keylen );
if( !rc )
@ -99,6 +107,7 @@ write_header( cipher_filter_context_t *cfx, IOBUF a )
log_fatal("encrypt failed: %s\n", gcry_strerror(rc) );
iobuf_write(a, temp, nprefix+2);
cfx->header=1;
}
@ -120,6 +129,7 @@ cipher_filter( void *opaque, int control,
else if( control == IOBUFCTRL_FLUSH ) { /* encrypt */
assert(a);
if( !cfx->header ) {
write_status( STATUS_BEGIN_ENCRYPTION );
write_header( cfx, a );
}
if( cfx->mdc_hash )
@ -134,15 +144,26 @@ cipher_filter( void *opaque, int control,
if( cfx->mdc_hash ) {
byte *hash;
int hashlen = gcry_md_get_algo_dlen( gcry_md_get_algo( cfx->mdc_hash ) );
byte temp[22];
assert( hashlen == 20 );
/* we must hash the prefix of the MDC packet here */
temp[0] = 0xd3;
temp[1] = 0x14;
gcry_md_putc( cfx->mdc_hash, temp[0] );
gcry_md_putc( cfx->mdc_hash, temp[1] );
hash = gcry_md_read( cfx->mdc_hash, 0 );
rc = gcry_cipher_encrypt( cfx->cipher_hd, hash, hashlen, NULL, 0 );
memcpy(temp+2, hash, 20);
rc = gcry_cipher_encrypt( cfx->cipher_hd, temp, 22, NULL, 0 );
if( rc )
log_fatal("encrypt failed: %s\n", gcry_strerror(rc) );
if( iobuf_write( a, hash, hashlen ) )
rc = GPGERR_WRITE_FILE;
gcry_md_close( cfx->mdc_hash ); cfx->mdc_hash = NULL;
if( iobuf_write( a, temp, 22 ) )
log_error("writing MDC packet failed\n" );
}
gcry_cipher_close(cfx->cipher_hd);
write_status( STATUS_END_ENCRYPTION );
}
else if( control == IOBUFCTRL_DESC ) {
*(char**)buf = "cipher_filter";