/****************
 * Filter to do a complete public key encryption.
 */
int
encrypt_filter( void *opaque, int control,
	       IOBUF a, byte *buf, size_t *ret_len)
{
    size_t size = *ret_len;
    encrypt_filter_context_t *efx = opaque;
    int rc=0;

    if( control == IOBUFCTRL_UNDERFLOW ) { /* decrypt */
	BUG(); /* not used */
    }
    else if( control == IOBUFCTRL_FLUSH ) { /* encrypt */
	if( !efx->header_okay ) {
	    efx->cfx.dek = xmalloc_secure_clear( sizeof *efx->cfx.dek );

	    if( !opt.def_cipher_algo  ) { /* try to get it from the prefs */
		efx->cfx.dek->algo =
		  select_algo_from_prefs(efx->pk_list,PREFTYPE_SYM,-1,NULL);
		if( efx->cfx.dek->algo == -1 ) {
                    /* because 3DES is implicitly in the prefs, this can only
                     * happen if we do not have any public keys in the list */
		    efx->cfx.dek->algo = DEFAULT_CIPHER_ALGO;
                }
	    }
	    else {
	      if(!opt.expert &&
		 select_algo_from_prefs(efx->pk_list,PREFTYPE_SYM,
					opt.def_cipher_algo,
					NULL)!=opt.def_cipher_algo)
		log_info(_("forcing symmetric cipher %s (%d) "
			   "violates recipient preferences\n"),
			 cipher_algo_to_string(opt.def_cipher_algo),
			 opt.def_cipher_algo);

	      efx->cfx.dek->algo = opt.def_cipher_algo;
	    }

            efx->cfx.dek->use_mdc = use_mdc(efx->pk_list,efx->cfx.dek->algo);

	    make_session_key( efx->cfx.dek );
	    if( DBG_CIPHER )
		log_hexdump("DEK is: ",
			     efx->cfx.dek->key, efx->cfx.dek->keylen );

	    rc = write_pubkey_enc_from_list( efx->pk_list, efx->cfx.dek, a );
	    if( rc )
		return rc;

	    if(efx->symkey_s2k && efx->symkey_dek)
	      {
		rc=write_symkey_enc(efx->symkey_s2k,efx->symkey_dek,
				    efx->cfx.dek,a);
		if(rc)
		  return rc;
	      }

	    iobuf_push_filter( a, cipher_filter, &efx->cfx );

	    efx->header_okay = 1;
	}
	rc = iobuf_write( a, buf, size );

    }
    else if( control == IOBUFCTRL_FREE )
      {
	xfree(efx->symkey_dek);
	xfree(efx->symkey_s2k);
      }
    else if( control == IOBUFCTRL_DESC ) {
	*(char**)buf = "encrypt_filter";
    }
    return rc;
}
/****************
 * Write pubkey-enc packets from the list of PKs to OUT.
 */
static int
write_pubkey_enc_from_list( PK_LIST pk_list, DEK *dek, IOBUF out )
{
    PACKET pkt;
    PKT_public_key *pk;
    PKT_pubkey_enc  *enc;
    int rc;

    for( ; pk_list; pk_list = pk_list->next ) {
	MPI frame;

	pk = pk_list->pk;

	print_pubkey_algo_note( pk->pubkey_algo );
	enc = xmalloc_clear( sizeof *enc );
	enc->pubkey_algo = pk->pubkey_algo;
	keyid_from_pk( pk, enc->keyid );
	enc->throw_keyid = (opt.throw_keyid || (pk_list->flags&1));

	if(opt.throw_keyid && (PGP2 || PGP6 || PGP7 || PGP8))
	  {
	    log_info(_("you may not use %s while in %s mode\n"),
		     "--throw-keyid",compliance_option_string());
	    compliance_failure();
	  }

	/* Okay, what's going on: We have the session key somewhere in
	 * the structure DEK and want to encode this session key in
	 * an integer value of n bits.	pubkey_nbits gives us the
	 * number of bits we have to use.  We then encode the session
	 * key in some way and we get it back in the big intger value
	 * FRAME.  Then we use FRAME, the public key PK->PKEY and the
	 * algorithm number PK->PUBKEY_ALGO and pass it to pubkey_encrypt
	 * which returns the encrypted value in the array ENC->DATA.
	 * This array has a size which depends on the used algorithm
	 * (e.g. 2 for Elgamal).  We don't need frame anymore because we
	 * have everything now in enc->data which is the passed to
	 * build_packet()
	 */
	frame = encode_session_key( dek, pubkey_nbits( pk->pubkey_algo,
							  pk->pkey ) );
	rc = pubkey_encrypt( pk->pubkey_algo, enc->data, frame, pk->pkey );
	mpi_free( frame );
	if( rc )
	    log_error("pubkey_encrypt failed: %s\n", g10_errstr(rc) );
	else {
	    if( opt.verbose ) {
		char *ustr = get_user_id_string_native (enc->keyid);
		log_info(_("%s/%s encrypted for: \"%s\"\n"),
		    pubkey_algo_to_string(enc->pubkey_algo),
		    cipher_algo_to_string(dek->algo), ustr );
		xfree(ustr);
	    }
	    /* and write it */
	    init_packet(&pkt);
	    pkt.pkttype = PKT_PUBKEY_ENC;
	    pkt.pkt.pubkey_enc = enc;
	    rc = build_packet( out, &pkt );
	    if( rc )
	       log_error("build_packet(pubkey_enc) failed: %s\n", g10_errstr(rc));
	}
	free_pubkey_enc(enc);
	if( rc )
	    return rc;
    }
    return 0;
}
/****************
 * Encrypt the file with the given userids (or ask if none
 * is supplied).
 */
int
encode_crypt( const char *filename, STRLIST remusr, int use_symkey )
{
    IOBUF inp = NULL, out = NULL;
    PACKET pkt;
    PKT_plaintext *pt = NULL;
    DEK *symkey_dek = NULL;
    STRING2KEY *symkey_s2k = NULL;
    int rc = 0, rc2 = 0;
    u32 filesize;
    cipher_filter_context_t cfx;
    armor_filter_context_t afx;
    compress_filter_context_t zfx;
    text_filter_context_t tfx;
    progress_filter_context_t pfx;
    PK_LIST pk_list,work_list;
    int do_compress = opt.compress_algo && !RFC1991;

    memset( &cfx, 0, sizeof cfx);
    memset( &afx, 0, sizeof afx);
    memset( &zfx, 0, sizeof zfx);
    memset( &tfx, 0, sizeof tfx);
    init_packet(&pkt);

    if(use_symkey
       && (rc=setup_symkey(&symkey_s2k,&symkey_dek)))
      return rc;

    if( (rc=build_pk_list( remusr, &pk_list, PUBKEY_USAGE_ENC)) )
	return rc;

    if(PGP2) {
      for(work_list=pk_list; work_list; work_list=work_list->next)
	if(!(is_RSA(work_list->pk->pubkey_algo) &&
	     nbits_from_pk(work_list->pk)<=2048))
	  {
	    log_info(_("you can only encrypt to RSA keys of 2048 bits or "
		       "less in --pgp2 mode\n"));
	    compliance_failure();
	    break;
	  }
    }

    /* prepare iobufs */
    inp = iobuf_open(filename);
    if (inp)
      iobuf_ioctl (inp,3,1,NULL); /* disable fd caching */
    if (inp && is_secured_file (iobuf_get_fd (inp)))
      {
        iobuf_close (inp);
        inp = NULL;
        errno = EPERM;
      }
    if( !inp ) {
	log_error(_("can't open `%s': %s\n"), filename? filename: "[stdin]",
					strerror(errno) );
	rc = G10ERR_OPEN_FILE;
	goto leave;
    }
    else if( opt.verbose )
	log_info(_("reading from `%s'\n"), filename? filename: "[stdin]");

    handle_progress (&pfx, inp, filename);

    if( opt.textmode )
	iobuf_push_filter( inp, text_filter, &tfx );

    if( (rc = open_outfile( filename, opt.armor? 1:0, &out )) )
	goto leave;

    if( opt.armor )
	iobuf_push_filter( out, armor_filter, &afx );

    /* create a session key */
    cfx.dek = xmalloc_secure_clear (sizeof *cfx.dek);
    if( !opt.def_cipher_algo ) { /* try to get it from the prefs */
	cfx.dek->algo = select_algo_from_prefs(pk_list,PREFTYPE_SYM,-1,NULL);
	/* The only way select_algo_from_prefs can fail here is when
           mixing v3 and v4 keys, as v4 keys have an implicit
           preference entry for 3DES, and the pk_list cannot be empty.
           In this case, use 3DES anyway as it's the safest choice -
           perhaps the v3 key is being used in an OpenPGP
           implementation and we know that the implementation behind
           any v4 key can handle 3DES. */
	if( cfx.dek->algo == -1 ) {
	    cfx.dek->algo = CIPHER_ALGO_3DES;

	    if( PGP2 ) {
	      log_info(_("unable to use the IDEA cipher for all of the keys "
			 "you are encrypting to.\n"));
	      compliance_failure();
	    }
	}
    }
    else {
      if(!opt.expert &&
	 select_algo_from_prefs(pk_list,PREFTYPE_SYM,
				opt.def_cipher_algo,NULL)!=opt.def_cipher_algo)
	log_info(_("WARNING: forcing symmetric cipher %s (%d)"
		   " violates recipient preferences\n"),
		 cipher_algo_to_string(opt.def_cipher_algo),
		 opt.def_cipher_algo);

      cfx.dek->algo = opt.def_cipher_algo;
    }

    cfx.dek->use_mdc=use_mdc(pk_list,cfx.dek->algo);

    /* Only do the is-file-already-compressed check if we are using a
       MDC.  This forces compressed files to be re-compressed if we do
       not have a MDC to give some protection against chosen
       ciphertext attacks. */

    if (do_compress && cfx.dek->use_mdc && is_file_compressed(filename, &rc2) )
      {
        if (opt.verbose)
          log_info(_("`%s' already compressed\n"), filename);
        do_compress = 0;        
      }
    if (rc2)
      {
        rc = rc2;
        goto leave;
      }

    make_session_key( cfx.dek );
    if( DBG_CIPHER )
	log_hexdump("DEK is: ", cfx.dek->key, cfx.dek->keylen );

    rc = write_pubkey_enc_from_list( pk_list, cfx.dek, out );
    if( rc  )
	goto leave;

    /* We put the passphrase (if any) after any public keys as this
       seems to be the most useful on the recipient side - there is no
       point in prompting a user for a passphrase if they have the
       secret key needed to decrypt. */
    if(use_symkey && (rc=write_symkey_enc(symkey_s2k,symkey_dek,cfx.dek,out)))
      goto leave;

    if (!opt.no_literal) {
	/* setup the inner packet */
	if( filename || opt.set_filename ) {
	    char *s = make_basename( opt.set_filename ? opt.set_filename
						      : filename,
				     iobuf_get_real_fname( inp ) );
	    pt = xmalloc( sizeof *pt + strlen(s) - 1 );
	    pt->namelen = strlen(s);
	    memcpy(pt->name, s, pt->namelen );
	    xfree(s);
	}
	else { /* no filename */
	    pt = xmalloc( sizeof *pt - 1 );
	    pt->namelen = 0;
	}
    }

    if (!iobuf_is_pipe_filename (filename) && *filename && !opt.textmode )
      {
        off_t tmpsize;
        int overflow;

	if ( !(tmpsize = iobuf_get_filelength(inp, &overflow))
             && !overflow )
          log_info(_("WARNING: `%s' is an empty file\n"), filename );
        /* We can't encode the length of very large files because
           OpenPGP uses only 32 bit for file sizes.  So if the the
           size of a file is larger than 2^32 minus some bytes for
           packet headers, we switch to partial length encoding. */
        if (tmpsize < (IOBUF_FILELENGTH_LIMIT - 65536) )
          filesize = tmpsize;
        else
          filesize = 0;
      }
    else
      filesize = opt.set_filesize ? opt.set_filesize : 0; /* stdin */

    if (!opt.no_literal) {
	pt->timestamp = make_timestamp();
	pt->mode = opt.textmode ? 't' : 'b';
	pt->len = filesize;
	pt->new_ctb = !pt->len && !RFC1991;
	pt->buf = inp;
	pkt.pkttype = PKT_PLAINTEXT;
	pkt.pkt.plaintext = pt;
	cfx.datalen = filesize && !do_compress? calc_packet_length( &pkt ) : 0;
    }
    else
	cfx.datalen = filesize && !do_compress ? filesize : 0;

    /* register the cipher filter */
    iobuf_push_filter( out, cipher_filter, &cfx );

    /* register the compress filter */
    if( do_compress ) {
	int compr_algo = opt.compress_algo;

	if(compr_algo==-1)
	  {
	    if((compr_algo=
		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,-1,NULL))==-1)
	      compr_algo=DEFAULT_COMPRESS_ALGO;
	    /* Theoretically impossible to get here since uncompressed
	       is implicit. */
	  }
	else if(!opt.expert &&
		select_algo_from_prefs(pk_list,PREFTYPE_ZIP,
				       compr_algo,NULL)!=compr_algo)
	  log_info(_("WARNING: forcing compression algorithm %s (%d)"
		     " violates recipient preferences\n"),
		   compress_algo_to_string(compr_algo),compr_algo);

	/* algo 0 means no compression */
	if( compr_algo )
	  {
            if (cfx.dek && cfx.dek->use_mdc)
              zfx.new_ctb = 1;
	    push_compress_filter(out,&zfx,compr_algo);
	  }
    }

    /* do the work */
    if (!opt.no_literal) {
	if( (rc = build_packet( out, &pkt )) )
	    log_error("build_packet failed: %s\n", g10_errstr(rc) );
    }
    else {
	/* user requested not to create a literal packet, so we copy
           the plain data */
	byte copy_buffer[4096];
	int  bytes_copied;
	while ((bytes_copied = iobuf_read(inp, copy_buffer, 4096)) != -1)
	    if (iobuf_write(out, copy_buffer, bytes_copied) == -1) {
		rc = G10ERR_WRITE_FILE;
		log_error("copying input to output failed: %s\n",
                          g10_errstr(rc) );
		break;
	    }
	wipememory(copy_buffer, 4096); /* burn buffer */
    }

    /* finish the stuff */
  leave:
    iobuf_close(inp);
    if( rc )
	iobuf_cancel(out);
    else {
	iobuf_close(out); /* fixme: check returncode */
        write_status( STATUS_END_ENCRYPTION );
    }
    if( pt )
	pt->buf = NULL;
    free_packet(&pkt);
    xfree(cfx.dek);
    xfree(symkey_dek);
    xfree(symkey_s2k);
    release_pk_list( pk_list );
    return rc;
}
/* We don't want to use use_seskey yet because older gnupg versions
   can't handle it, and there isn't really any point unless we're
   making a message that can be decrypted by a public key or
   passphrase. */
static int
encode_simple( const char *filename, int mode, int use_seskey )
{
    IOBUF inp, out;
    PACKET pkt;
    PKT_plaintext *pt = NULL;
    STRING2KEY *s2k = NULL;
    byte enckey[33];
    int rc = 0;
    int seskeylen = 0;
    u32 filesize;
    cipher_filter_context_t cfx;
    armor_filter_context_t afx;
    compress_filter_context_t zfx;
    text_filter_context_t tfx;
    progress_filter_context_t pfx;
    int do_compress = !RFC1991 && default_compress_algo();

    memset( &cfx, 0, sizeof cfx);
    memset( &afx, 0, sizeof afx);
    memset( &zfx, 0, sizeof zfx);
    memset( &tfx, 0, sizeof tfx);
    init_packet(&pkt);
    
    /* prepare iobufs */
    inp = iobuf_open(filename);
    if (inp)
      iobuf_ioctl (inp,3,1,NULL); /* disable fd caching */
    if (inp && is_secured_file (iobuf_get_fd (inp)))
      {
        iobuf_close (inp);
        inp = NULL;
        errno = EPERM;
      }
    if( !inp ) {
	log_error(_("can't open `%s': %s\n"), filename? filename: "[stdin]",
                  strerror(errno) );
	return G10ERR_OPEN_FILE;
    }

    handle_progress (&pfx, inp, filename);

    if( opt.textmode )
	iobuf_push_filter( inp, text_filter, &tfx );

    /* Due the the fact that we use don't use an IV to encrypt the
       session key we can't use the new mode with RFC1991 because
       it has no S2K salt. RFC1991 always uses simple S2K. */
    if ( RFC1991 && use_seskey )
        use_seskey = 0;
    
    cfx.dek = NULL;
    if( mode ) {
	s2k = xmalloc_clear( sizeof *s2k );
	s2k->mode = RFC1991? 0:opt.s2k_mode;
	s2k->hash_algo=S2K_DIGEST_ALGO;
	cfx.dek = passphrase_to_dek( NULL, 0,
				     default_cipher_algo(), s2k, 2,
                                     NULL, NULL);
	if( !cfx.dek || !cfx.dek->keylen ) {
	    rc = G10ERR_PASSPHRASE;
	    xfree(cfx.dek);
	    xfree(s2k);
	    iobuf_close(inp);
	    log_error(_("error creating passphrase: %s\n"), g10_errstr(rc) );
	    return rc;
	}
        if (use_seskey && s2k->mode != 1 && s2k->mode != 3) {
            use_seskey = 0;
            log_info (_("can't use a symmetric ESK packet "
                        "due to the S2K mode\n"));
        }

        if ( use_seskey )
	  {
	    DEK *dek = NULL;
            seskeylen = cipher_get_keylen( default_cipher_algo() ) / 8;
            encode_seskey( cfx.dek, &dek, enckey );
            xfree( cfx.dek ); cfx.dek = dek;
	  }

	if(opt.verbose)
	  log_info(_("using cipher %s\n"),
		   cipher_algo_to_string(cfx.dek->algo));

	cfx.dek->use_mdc=use_mdc(NULL,cfx.dek->algo);
    }

    if (do_compress && cfx.dek && cfx.dek->use_mdc
	&& is_file_compressed(filename, &rc))
      {
        if (opt.verbose)
          log_info(_("`%s' already compressed\n"), filename);
        do_compress = 0;        
      }

    if( rc || (rc = open_outfile( filename, opt.armor? 1:0, &out )) ) {
	iobuf_cancel(inp);
	xfree(cfx.dek);
	xfree(s2k);
	return rc;
    }

    if( opt.armor )
	iobuf_push_filter( out, armor_filter, &afx );

    if( s2k && !RFC1991 ) {
	PKT_symkey_enc *enc = xmalloc_clear( sizeof *enc + seskeylen + 1 );
	enc->version = 4;
	enc->cipher_algo = cfx.dek->algo;
	enc->s2k = *s2k;
        if ( use_seskey && seskeylen ) {
            enc->seskeylen = seskeylen + 1; /* algo id */
            memcpy( enc->seskey, enckey, seskeylen + 1 );
        }
	pkt.pkttype = PKT_SYMKEY_ENC;
	pkt.pkt.symkey_enc = enc;
	if( (rc = build_packet( out, &pkt )) )
	    log_error("build symkey packet failed: %s\n", g10_errstr(rc) );
	xfree(enc);
    }

    if (!opt.no_literal)
      pt=setup_plaintext_name(filename,inp);

    /* Note that PGP 5 has problems decrypting symmetrically encrypted
       data if the file length is in the inner packet. It works when
       only partial length headers are use.  In the past, we always
       used partial body length here, but since PGP 2, PGP 6, and PGP
       7 need the file length, and nobody should be using PGP 5
       nowadays anyway, this is now set to the file length.  Note also
       that this only applies to the RFC-1991 style symmetric
       messages, and not the RFC-2440 style.  PGP 6 and 7 work with
       either partial length or fixed length with the new style
       messages. */

    if ( !iobuf_is_pipe_filename (filename) && *filename && !opt.textmode )
      {
        off_t tmpsize;
        int overflow;

	if ( !(tmpsize = iobuf_get_filelength(inp, &overflow))
             && !overflow )
          log_info(_("WARNING: `%s' is an empty file\n"), filename );
        /* We can't encode the length of very large files because
           OpenPGP uses only 32 bit for file sizes.  So if the the
           size of a file is larger than 2^32 minus some bytes for
           packet headers, we switch to partial length encoding. */
        if ( tmpsize < (IOBUF_FILELENGTH_LIMIT - 65536) )
          filesize = tmpsize;
        else
          filesize = 0;
      }
    else
      filesize = opt.set_filesize ? opt.set_filesize : 0; /* stdin */

    if (!opt.no_literal) {
	pt->timestamp = make_timestamp();
	pt->mode = opt.textmode? 't' : 'b';
	pt->len = filesize;
	pt->new_ctb = !pt->len && !RFC1991;
	pt->buf = inp;
	pkt.pkttype = PKT_PLAINTEXT;
	pkt.pkt.plaintext = pt;
	cfx.datalen = filesize && !do_compress ? calc_packet_length( &pkt ) : 0;
    }
    else
      {
        cfx.datalen = filesize && !do_compress ? filesize : 0;
        pkt.pkttype = 0;
        pkt.pkt.generic = NULL;
      }

    /* register the cipher filter */
    if( mode )
	iobuf_push_filter( out, cipher_filter, &cfx );
    /* register the compress filter */
    if( do_compress )
      {
        if (cfx.dek && cfx.dek->use_mdc)
          zfx.new_ctb = 1;
	push_compress_filter(out,&zfx,default_compress_algo());
      }

    /* do the work */
    if (!opt.no_literal) {
	if( (rc = build_packet( out, &pkt )) )
	    log_error("build_packet failed: %s\n", g10_errstr(rc) );
    }
    else {
	/* user requested not to create a literal packet,
	 * so we copy the plain data */
	byte copy_buffer[4096];
	int  bytes_copied;
	while ((bytes_copied = iobuf_read(inp, copy_buffer, 4096)) != -1)
	    if (iobuf_write(out, copy_buffer, bytes_copied) == -1) {
		rc = G10ERR_WRITE_FILE;
		log_error("copying input to output failed: %s\n", g10_errstr(rc) );
		break;
	    }
	wipememory(copy_buffer, 4096); /* burn buffer */
    }

    /* finish the stuff */
    iobuf_close(inp);
    if (rc)
	iobuf_cancel(out);
    else {
	iobuf_close(out); /* fixme: check returncode */
        if (mode)
            write_status( STATUS_END_ENCRYPTION );
    }
    if (pt)
	pt->buf = NULL;
    free_packet(&pkt);
    xfree(cfx.dek);
    xfree(s2k);
    return rc;
}
static int
get_it( PKT_pubkey_enc *enc, DEK *dek, PKT_secret_key *sk, u32 *keyid )
{
  int rc;
  MPI plain_dek  = NULL;
  byte *frame = NULL;
  unsigned n, nframe;
  u16 csum, csum2;
  
  int card = 0;

  if (sk->is_protected && sk->protect.s2k.mode == 1002)
    { /* Note, that we only support RSA for now. */
#ifdef ENABLE_CARD_SUPPORT
      unsigned char *rbuf;
      size_t rbuflen;
      char *snbuf;
      unsigned char *indata = NULL;
      unsigned int indatalen;

      snbuf = serialno_and_fpr_from_sk (sk->protect.iv, sk->protect.ivlen, sk);

      indata = mpi_get_buffer (enc->data[0], &indatalen, NULL);
      if (!indata)
        BUG ();

      rc = agent_scd_pkdecrypt (snbuf, indata, indatalen, &rbuf, &rbuflen);
      xfree (snbuf);
      xfree (indata);
      if (rc)
        goto leave;

      frame = rbuf;
      nframe = rbuflen;
      card = 1;
#else
      rc = G10ERR_UNSUPPORTED;
      goto leave;
#endif /*!ENABLE_CARD_SUPPORT*/
    }
  else
    {
      rc = pubkey_decrypt(sk->pubkey_algo, &plain_dek, enc->data, sk->skey );
      if( rc )
	goto leave;
      frame = mpi_get_buffer( plain_dek, &nframe, NULL );
      mpi_free( plain_dek ); plain_dek = NULL;
    }

    /* Now get the DEK (data encryption key) from the frame
     *
     * Old versions encode the DEK in in this format (msb is left):
     *
     *	   0  1  DEK(16 bytes)	CSUM(2 bytes)  0  RND(n bytes) 2
     *
     * Later versions encode the DEK like this:
     *
     *	   0  2  RND(n bytes)  0  A  DEK(k bytes)  CSUM(2 bytes)
     *
     * (mpi_get_buffer already removed the leading zero).
     *
     * RND are non-zero randow bytes.
     * A   is the cipher algorithm
     * DEK is the encryption key (session key) with length k
     * CSUM
     */
    if( DBG_CIPHER )
	log_hexdump("DEK frame:", frame, nframe );
    n=0;
    if (!card)
      {
        if( n + 7 > nframe )
          { rc = G10ERR_WRONG_SECKEY; goto leave; }
        if( frame[n] == 1 && frame[nframe-1] == 2 ) {
          log_info(_("old encoding of the DEK is not supported\n"));
          rc = G10ERR_CIPHER_ALGO;
          goto leave;
        }
        if( frame[n] != 2 )  /* somethink is wrong */
          { rc = G10ERR_WRONG_SECKEY; goto leave; }
        for(n++; n < nframe && frame[n]; n++ ) /* skip the random bytes */
          ;
        n++; /* and the zero byte */
      }

    if( n + 4 > nframe )
	{ rc = G10ERR_WRONG_SECKEY; goto leave; }

    dek->keylen = nframe - (n+1) - 2;
    dek->algo = frame[n++];
    if( dek->algo ==  CIPHER_ALGO_IDEA )
	write_status(STATUS_RSA_OR_IDEA);
    rc = check_cipher_algo( dek->algo );
    if( rc ) {
	if( !opt.quiet && rc == G10ERR_CIPHER_ALGO ) {
	    log_info(_("cipher algorithm %d%s is unknown or disabled\n"),
                     dek->algo, dek->algo == CIPHER_ALGO_IDEA? " (IDEA)":"");
	    if(dek->algo==CIPHER_ALGO_IDEA)
	      idea_cipher_warn(0);
	}
	dek->algo = 0;
	goto leave;
    }
    if( (dek->keylen*8) != cipher_get_keylen( dek->algo ) ) {
	rc = G10ERR_WRONG_SECKEY;
	goto leave;
    }

    /* copy the key to DEK and compare the checksum */
    csum  = frame[nframe-2] << 8;
    csum |= frame[nframe-1];
    memcpy( dek->key, frame+n, dek->keylen );
    for( csum2=0, n=0; n < dek->keylen; n++ )
	csum2 += dek->key[n];
    if( csum != csum2 ) {
	rc = G10ERR_WRONG_SECKEY;
	goto leave;
    }
    if( DBG_CIPHER )
	log_hexdump("DEK is:", dek->key, dek->keylen );
    /* check that the algo is in the preferences and whether it has expired */
    {
	PKT_public_key *pk = NULL;
        KBNODE pkb = get_pubkeyblock (keyid);

	if( !pkb ) {
            rc = -1;
	    log_error("oops: public key not found for preference check\n");
        }
	else if(pkb->pkt->pkt.public_key->selfsigversion > 3
		&& dek->algo != CIPHER_ALGO_3DES
		&& !opt.quiet
		&& !is_algo_in_prefs( pkb, PREFTYPE_SYM, dek->algo ))
	  log_info(_("WARNING: cipher algorithm %s not found in recipient"
		     " preferences\n"),cipher_algo_to_string(dek->algo));
        if (!rc) {
            KBNODE k;
            
            for (k=pkb; k; k = k->next) {
                if (k->pkt->pkttype == PKT_PUBLIC_KEY 
                    || k->pkt->pkttype == PKT_PUBLIC_SUBKEY){
                    u32 aki[2];
        	    keyid_from_pk(k->pkt->pkt.public_key, aki);

                    if (aki[0]==keyid[0] && aki[1]==keyid[1]) {
                        pk = k->pkt->pkt.public_key;
                        break;
                    }
                }
            }
            if (!pk)
                BUG ();
            if ( pk->expiredate && pk->expiredate <= make_timestamp() ) {
                log_info(_("NOTE: secret key %s expired at %s\n"),
                         keystr(keyid), asctimestamp( pk->expiredate) );
            }
        }

        if ( pk &&  pk->is_revoked ) {
            log_info( _("NOTE: key has been revoked") );
            putc( '\n', log_stream() );
            show_revocation_reason( pk, 1 );
        }

	release_kbnode (pkb);
	rc = 0;
    }


  leave:
    mpi_free(plain_dek);
    xfree(frame);
    return rc;
}
Esempio n. 6
0
/* Map the cipher algorithm identifier ALGORITHM to a string
   representing this algorithm.  This string is the default name as
   used by Libgcrypt.  An pointer to an empty string is returned for
   an unknown algorithm.  NULL is never returned. */
const char *
gcry_cipher_algo_name (int algorithm)
{
  return cipher_algo_to_string (algorithm);
}
Esempio n. 7
0
/* Map the cipher algorithm identifier ALGORITHM to a string
   representing this algorithm.  This string is the default name as
   used by Libgcrypt.  An pointer to an empty string is returned for
   an unknown algorithm.  NULL is never returned. */
const char *
gcry_cipher_algo_name (int algorithm)
{
  const char *s = cipher_algo_to_string (algorithm);
  return s ? s : "";
}