static void
write_header( cipher_filter_context_t *cfx, IOBUF a )
{
PACKET pkt;
PKT_encrypted ed;
byte temp[18];
unsigned blocksize;
unsigned nprefix;
blocksize = cipher_get_blocksize( cfx->dek->algo );
if( blocksize < 8 || blocksize > 16 )
log_fatal("unsupported blocksize %u\n", blocksize );
memset( &ed, 0, sizeof ed );
ed.len = cfx->datalen;
ed.extralen = blocksize+2;
ed.new_ctb = !ed.len && !RFC1991;
if( cfx->dek->use_mdc ) {
ed.mdc_method = DIGEST_ALGO_SHA1;
cfx->mdc_hash = md_open( DIGEST_ALGO_SHA1, 0 );
if ( DBG_HASHING )
md_start_debug( cfx->mdc_hash, "creatmdc" );
}
{
char buf[20];
sprintf (buf, "%d %d", ed.mdc_method, cfx->dek->algo);
write_status_text (STATUS_BEGIN_ENCRYPTION, buf);
}
init_packet( &pkt );
pkt.pkttype = cfx->dek->use_mdc? PKT_ENCRYPTED_MDC : PKT_ENCRYPTED;
pkt.pkt.encrypted = &ed;
if( build_packet( a, &pkt ))
log_bug("build_packet(ENCR_DATA) failed\n");
nprefix = blocksize;
randomize_buffer( temp, nprefix, 1 );
temp[nprefix] = temp[nprefix-2];
temp[nprefix+1] = temp[nprefix-1];
print_cipher_algo_note( cfx->dek->algo );
cfx->cipher_hd = cipher_open( cfx->dek->algo,
cfx->dek->use_mdc? CIPHER_MODE_CFB
: CIPHER_MODE_AUTO_CFB, 1 );
/* log_hexdump( "thekey", cfx->dek->key, cfx->dek->keylen );*/
cipher_setkey( cfx->cipher_hd, cfx->dek->key, cfx->dek->keylen );
cipher_setiv( cfx->cipher_hd, NULL, 0 );
/* log_hexdump( "prefix", temp, nprefix+2 ); */
if( cfx->mdc_hash ) /* hash the "IV" */
md_write( cfx->mdc_hash, temp, nprefix+2 );
cipher_encrypt( cfx->cipher_hd, temp, temp, nprefix+2);
cipher_sync( cfx->cipher_hd );
iobuf_write(a, temp, nprefix+2);
cfx->header=1;
}
static void
write_header (cipher_filter_context_t *cfx, iobuf_t a)
{
gcry_error_t err;
PACKET pkt;
PKT_encrypted ed;
byte temp[18];
unsigned int blocksize;
unsigned int nprefix;
blocksize = openpgp_cipher_get_algo_blklen (cfx->dek->algo);
if ( blocksize < 8 || blocksize > 16 )
log_fatal ("unsupported blocksize %u\n", blocksize);
memset (&ed, 0, sizeof ed);
ed.len = cfx->datalen;
ed.extralen = blocksize + 2;
ed.new_ctb = !ed.len;
if (cfx->dek->use_mdc)
{
ed.mdc_method = DIGEST_ALGO_SHA1;
gcry_md_open (&cfx->mdc_hash, DIGEST_ALGO_SHA1, 0);
if (DBG_HASHING)
gcry_md_debug (cfx->mdc_hash, "creatmdc");
}
else if (!opt.no_mdc_warn)
{
log_info ("WARNING: "
"encrypting without integrity protection is dangerous\n");
}
write_status_printf (STATUS_BEGIN_ENCRYPTION, "%d %d",
ed.mdc_method, cfx->dek->algo);
init_packet (&pkt);
pkt.pkttype = cfx->dek->use_mdc? PKT_ENCRYPTED_MDC : PKT_ENCRYPTED;
pkt.pkt.encrypted = &ed;
if (build_packet( a, &pkt))
log_bug ("build_packet(ENCR_DATA) failed\n");
nprefix = blocksize;
gcry_randomize (temp, nprefix, GCRY_STRONG_RANDOM );
temp[nprefix] = temp[nprefix-2];
temp[nprefix+1] = temp[nprefix-1];
print_cipher_algo_note (cfx->dek->algo);
err = openpgp_cipher_open (&cfx->cipher_hd,
cfx->dek->algo,
GCRY_CIPHER_MODE_CFB,
(GCRY_CIPHER_SECURE
| ((cfx->dek->use_mdc || cfx->dek->algo >= 100)?
0 : GCRY_CIPHER_ENABLE_SYNC)));
if (err)
{
/* We should never get an error here cause we already checked,
* that the algorithm is available. */
BUG();
}
/* log_hexdump ("thekey", cfx->dek->key, cfx->dek->keylen); */
gcry_cipher_setkey (cfx->cipher_hd, cfx->dek->key, cfx->dek->keylen);
gcry_cipher_setiv (cfx->cipher_hd, NULL, 0);
/* log_hexdump ("prefix", temp, nprefix+2); */
if (cfx->mdc_hash) /* Hash the "IV". */
gcry_md_write (cfx->mdc_hash, temp, nprefix+2 );
gcry_cipher_encrypt (cfx->cipher_hd, temp, nprefix+2, NULL, 0);
gcry_cipher_sync (cfx->cipher_hd);
iobuf_write (a, temp, nprefix+2);
cfx->short_blklen_warn = (blocksize < 16);
cfx->short_blklen_count = nprefix+2;
cfx->wrote_header = 1;
}
/****************
* Protect the secret key with the passphrase from DEK
*/
int
protect_secret_key( PKT_secret_key *sk, DEK *dek )
{
int i,j, rc = 0;
byte *buffer;
size_t nbytes;
u16 csum;
if( !dek )
return 0;
if( !sk->is_protected ) { /* okay, apply the protection */
gcry_cipher_hd_t cipher_hd=NULL;
if ( openpgp_cipher_test_algo ( sk->protect.algo ) ) {
/* Unsupport protection algorithm. */
rc = gpg_error (GPG_ERR_CIPHER_ALGO);
}
else {
print_cipher_algo_note( sk->protect.algo );
if ( openpgp_cipher_open (&cipher_hd, sk->protect.algo,
GCRY_CIPHER_MODE_CFB,
(GCRY_CIPHER_SECURE
| (sk->protect.algo >= 100 ?
0 : GCRY_CIPHER_ENABLE_SYNC))) )
BUG();
if ( gcry_cipher_setkey ( cipher_hd, dek->key, dek->keylen ) )
log_info(_("WARNING: Weak key detected"
" - please change passphrase again.\n"));
sk->protect.ivlen = openpgp_cipher_get_algo_blklen (sk->protect.algo);
assert( sk->protect.ivlen <= DIM(sk->protect.iv) );
if( sk->protect.ivlen != 8 && sk->protect.ivlen != 16 )
BUG(); /* yes, we are very careful */
gcry_create_nonce (sk->protect.iv, sk->protect.ivlen);
gcry_cipher_setiv (cipher_hd, sk->protect.iv, sk->protect.ivlen);
if( sk->version >= 4 ) {
byte *bufarr[PUBKEY_MAX_NSKEY];
size_t narr[PUBKEY_MAX_NSKEY];
unsigned int nbits[PUBKEY_MAX_NSKEY];
int ndata=0;
byte *p, *data;
for (j=0, i = pubkey_get_npkey(sk->pubkey_algo);
i < pubkey_get_nskey(sk->pubkey_algo); i++, j++ )
{
assert (!gcry_mpi_get_flag (sk->skey[i],
GCRYMPI_FLAG_OPAQUE));
if (gcry_mpi_aprint (GCRYMPI_FMT_USG, bufarr+j,
narr+j, sk->skey[i]))
BUG();
nbits[j] = gcry_mpi_get_nbits (sk->skey[i]);
ndata += narr[j] + 2;
}
for ( ; j < PUBKEY_MAX_NSKEY; j++ )
bufarr[j] = NULL;
ndata += opt.simple_sk_checksum? 2 : 20; /* for checksum */
data = xmalloc_secure( ndata );
p = data;
for(j=0; j < PUBKEY_MAX_NSKEY && bufarr[j]; j++ ) {
p[0] = nbits[j] >> 8 ;
p[1] = nbits[j];
p += 2;
memcpy(p, bufarr[j], narr[j] );
p += narr[j];
xfree(bufarr[j]);
}
if (opt.simple_sk_checksum) {
log_info (_("generating the deprecated 16-bit checksum"
" for secret key protection\n"));
csum = checksum( data, ndata-2);
sk->csum = csum;
*p++ = csum >> 8;
*p++ = csum;
sk->protect.sha1chk = 0;
}
else {
