Rename encode.c to encrypt.c.

Rename function in a simlar way.
Re-indent encrypt.c

1 files changed, 957 insertions, 0 deletions

diff --git a/g10/encrypt.c b/g10/encrypt.c
new file mode 100644
index 000000000..90a206522
--- /dev/null
+++ b/g10/encrypt.c
@@ -0,0 +1,957 @@
+/* encrypt.c - Main encryption driver
+ * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
+ *               2006, 2009 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "gpg.h"
+#include "options.h"
+#include "packet.h"
+#include "status.h"
+#include "iobuf.h"
+#include "keydb.h"
+#include "util.h"
+#include "main.h"
+#include "filter.h"
+#include "trustdb.h"
+#include "i18n.h"
+#include "status.h"
+#include "pkglue.h"
+
+
+static int encrypt_simple( const char *filename, int mode, int use_seskey );
+static int write_pubkey_enc_from_list( PK_LIST pk_list, DEK *dek, iobuf_t out );
+
+/****************
+ * Encrypt FILENAME with only the symmetric cipher.  Take input from
+ * stdin if FILENAME is NULL.
+ */
+int
+encrypt_symmetric (const char *filename)
+{
+  return encrypt_simple( filename, 1, 0 );
+}
+
+
+/****************
+ * Encrypt FILENAME as a literal data packet only. Take input from
+ * stdin if FILENAME is NULL.
+ */
+int
+encrypt_store (const char *filename)
+{
+  return encrypt_simple( filename, 0, 0 );
+}
+
+
+static void
+encrypt_seskey (DEK *dek, DEK **seskey, byte *enckey)
+{
+  gcry_cipher_hd_t hd;
+  byte buf[33];
+
+  assert ( dek->keylen <= 32 );
+  if (!*seskey)
+    {
+      *seskey=xmalloc_clear(sizeof(DEK));
+      (*seskey)->keylen=dek->keylen;
+      (*seskey)->algo=dek->algo;
+      make_session_key(*seskey);
+      /*log_hexdump( "thekey", c->key, c->keylen );*/
+    }
+
+  /* The encrypted session key is prefixed with a one-octet algorithm id.  */
+  buf[0] = (*seskey)->algo;
+  memcpy( buf + 1, (*seskey)->key, (*seskey)->keylen );
+    
+  /* We only pass already checked values to the following fucntion,
+     thus we consider any failure as fatal.  */
+  if (openpgp_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1))
+    BUG ();
+  if (gcry_cipher_setkey (hd, dek->key, dek->keylen))
+    BUG ();
+  gcry_cipher_setiv (hd, NULL, 0);
+  gcry_cipher_encrypt (hd, buf, (*seskey)->keylen + 1, NULL, 0);
+  gcry_cipher_close (hd);
+
+  memcpy( enckey, buf, (*seskey)->keylen + 1 );
+  wipememory( buf, sizeof buf ); /* burn key */
+}
+
+
+/* We try very hard to use a MDC */
+static int
+use_mdc(PK_LIST pk_list,int algo)
+{
+  /* RFC-1991 and 2440 don't have MDC */
+  if(RFC1991 || RFC2440)
+    return 0;
+
+  /* --force-mdc overrides --disable-mdc */
+  if(opt.force_mdc)
+    return 1;
+
+  if(opt.disable_mdc)
+    return 0;
+
+  /* Do the keys really support MDC? */
+
+  if(select_mdc_from_pklist(pk_list))
+    return 1;
+  
+  /* The keys don't support MDC, so now we do a bit of a hack - if any
+     of the AESes or TWOFISH are in the prefs, we assume that the user
+     can handle a MDC.  This is valid for PGP 7, which can handle MDCs
+     though it will not generate them.  2440bis allows this, by the
+     way. */
+
+  if(select_algo_from_prefs(pk_list,PREFTYPE_SYM,
+			    CIPHER_ALGO_AES,NULL)==CIPHER_ALGO_AES)
+    return 1;
+
+  if(select_algo_from_prefs(pk_list,PREFTYPE_SYM,
+			    CIPHER_ALGO_AES192,NULL)==CIPHER_ALGO_AES192)
+    return 1;
+
+  if(select_algo_from_prefs(pk_list,PREFTYPE_SYM,
+			    CIPHER_ALGO_AES256,NULL)==CIPHER_ALGO_AES256)
+    return 1;
+
+  if(select_algo_from_prefs(pk_list,PREFTYPE_SYM,
+			    CIPHER_ALGO_TWOFISH,NULL)==CIPHER_ALGO_TWOFISH)
+    return 1;
+
+  /* Last try.  Use MDC for the modern ciphers. */
+
+  if (openpgp_cipher_get_algo_blklen (algo) != 8)
+    return 1;
+
+  if (opt.verbose)
+    warn_missing_mdc_from_pklist (pk_list);
+
+  return 0; /* No MDC */
+}
+
+
+/* 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
+encrypt_simple (const char *filename, int mode, int use_seskey)
+{
+  iobuf_t 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 = NULL;
+  compress_filter_context_t zfx;
+  text_filter_context_t tfx;
+  progress_filter_context_t *pfx;
+  int do_compress = !RFC1991 && default_compress_algo();
+
+  pfx = new_progress_context ();
+  memset( &cfx, 0, sizeof cfx);
+  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)
+    {
+      rc = gpg_error_from_syserror ();
+      log_error(_("can't open `%s': %s\n"), filename? filename: "[stdin]",
+                strerror(errno) );
+      release_progress_context (pfx);
+      return rc;
+    }
+  
+  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 ) 
+    {
+      int canceled;
+      
+      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, 4,
+                                   NULL, &canceled);
+      if ( !cfx.dek || !cfx.dek->keylen )
+        {
+          rc = gpg_error (canceled? GPG_ERR_CANCELED:GPG_ERR_INV_PASSPHRASE);
+          xfree (cfx.dek);
+          xfree (s2k);
+          iobuf_close (inp);
+          log_error (_("error creating passphrase: %s\n"), gpg_strerror (rc));
+          release_progress_context (pfx);
+          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 = openpgp_cipher_get_algo_keylen (default_cipher_algo ());
+          encrypt_seskey( cfx.dek, &dek, enckey );
+          xfree( cfx.dek ); cfx.dek = dek;
+        }
+      
+      if (opt.verbose)
+        log_info(_("using cipher %s\n"),
+                 openpgp_cipher_algo_name (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);
+      release_progress_context (pfx);
+      return rc;
+    }
+  
+  if ( opt.armor )
+    {
+      afx = new_armor_context ();
+      push_armor_filter (afx, out);
+    }
+
+  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 && opt.verbose)
+        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 ( (rc=iobuf_write(out, copy_buffer, bytes_copied)) ) {
+        log_error ("copying input to output failed: %s\n",
+                   gpg_strerror (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);
+  release_armor_context (afx);
+  release_progress_context (pfx);
+  return rc;
+}
+
+
+int
+setup_symkey (STRING2KEY **symkey_s2k,DEK **symkey_dek)
+{
+  int canceled;
+
+  *symkey_s2k=xmalloc_clear(sizeof(STRING2KEY));
+  (*symkey_s2k)->mode = opt.s2k_mode;
+  (*symkey_s2k)->hash_algo = S2K_DIGEST_ALGO;
+
+  *symkey_dek=passphrase_to_dek(NULL,0,opt.s2k_cipher_algo,
+				*symkey_s2k, 4, NULL, &canceled);
+  if(!*symkey_dek || !(*symkey_dek)->keylen)
+    {
+      xfree(*symkey_dek);
+      xfree(*symkey_s2k);
+      return gpg_error (canceled?GPG_ERR_CANCELED:GPG_ERR_BAD_PASSPHRASE);
+    }
+
+  return 0;
+}
+
+
+static int
+write_symkey_enc (STRING2KEY *symkey_s2k, DEK *symkey_dek, DEK *dek, 
+                  iobuf_t out)
+{
+  int rc, seskeylen = openpgp_cipher_get_algo_keylen (dek->algo);
+
+  PKT_symkey_enc *enc;
+  byte enckey[33];
+  PACKET pkt;
+
+  enc=xmalloc_clear(sizeof(PKT_symkey_enc)+seskeylen+1);
+  encrypt_seskey(symkey_dek,&dek,enckey);
+
+  enc->version = 4;
+  enc->cipher_algo = opt.s2k_cipher_algo;
+  enc->s2k = *symkey_s2k;
+  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_enc packet failed: %s\n",g10_errstr(rc));
+
+  xfree(enc);
+  return rc;
+}
+
+
+/*
+ * Encrypt the file with the given userids (or ask if none
+ * is supplied).
+ */
+int
+encrypt_crypt (const char *filename, strlist_t remusr, int use_symkey)
+{
+  iobuf_t inp = NULL;
+  iobuf_t 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 = NULL;
+  compress_filter_context_t zfx;
+  text_filter_context_t tfx;
+  progress_filter_context_t *pfx;
+  PK_LIST pk_list, work_list;
+  int do_compress;
+
+  do_compress = opt.compress_algo && !RFC1991;
+
+  pfx = new_progress_context ();
+  memset( &cfx, 0, sizeof cfx);
+  memset( &zfx, 0, sizeof zfx);
+  memset( &tfx, 0, sizeof tfx);
+  init_packet(&pkt);
+
+  if (use_symkey 
+      && (rc=setup_symkey(&symkey_s2k,&symkey_dek)))
+    {
+      release_progress_context (pfx);
+      return rc;
+    }
+
+  if ((rc = build_pk_list (remusr, &pk_list, PUBKEY_USAGE_ENC)))
+    {
+      release_progress_context (pfx);
+      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)
+    {
+      rc = gpg_error_from_syserror ();
+      log_error (_("can't open `%s': %s\n"),
+                 filename? filename: "[stdin]", gpg_strerror (rc) );
+      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)
+    {
+      afx = new_armor_context ();
+      push_armor_filter (afx, out);
+    }
+  
+  /* 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();
+            }
+        }
+
+      /* In case 3DES has been selected, print a warning if any key
+         does not have a preference for AES.  This should help to
+         indentify why encrypting to several recipients falls back to
+         3DES. */
+      if (opt.verbose && cfx.dek->algo == CIPHER_ALGO_3DES)
+        warn_missing_aes_from_pklist (pk_list);
+    }
+  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"),
+                   openpgp_cipher_algo_name (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_printhex ("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)
+    pt = setup_plaintext_name (filename, inp);
+  
+  if (!iobuf_is_pipe_filename (filename) && *filename && !opt.textmode )
+    {
+      off_t tmpsize;
+      int overflow;
+      
+      if ( !(tmpsize = iobuf_get_filelength(inp, &overflow))
+           && !overflow && opt.verbose)
+        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)
+        {
+          compr_algo = select_algo_from_prefs (pk_list, PREFTYPE_ZIP, -1, NULL);
+          if (compr_algo == -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 ((rc=iobuf_write(out, copy_buffer, bytes_copied)))
+          {
+            log_error ("copying input to output failed: %s\n",
+                       gpg_strerror (rc));
+            break;
+          }
+      wipememory (copy_buffer, 4096); /* Burn the 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);
+  release_armor_context (afx);
+  release_progress_context (pfx);
+  return rc;
+}
+
+
+/*
+ * Filter to do a complete public key encryption.
+ */
+int
+encrypt_filter (void *opaque, int control,
+                iobuf_t 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;
+                }
+              
+              /* In case 3DES has been selected, print a warning if
+                 any key does not have a preference for AES.  This
+                 should help to indentify why encrypting to several
+                 recipients falls back to 3DES. */
+              if (opt.verbose
+                  && efx->cfx.dek->algo == CIPHER_ALGO_3DES)
+                warn_missing_aes_from_pklist (efx->pk_list);
+	    }
+          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"),
+			 openpgp_cipher_algo_name (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_printhex ("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_t out)
+{
+  PACKET pkt;
+  PKT_public_key *pk;
+  PKT_pubkey_enc  *enc;
+  int rc;
+
+  for ( ; pk_list; pk_list = pk_list->next )
+    {
+      gcry_mpi_t 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 = pk_encrypt (pk->pubkey_algo, enc->data, frame, pk->pkey);
+      gcry_mpi_release (frame);
+      if (rc)
+        log_error ("pubkey_encrypt failed: %s\n", gpg_strerror (rc) );
+      else
+        {
+          if ( opt.verbose )
+            {
+              char *ustr = get_user_id_string_native (enc->keyid);
+              log_info (_("%s/%s encrypted for: \"%s\"\n"),
+                        gcry_pk_algo_name (enc->pubkey_algo),
+                        openpgp_cipher_algo_name (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;
+}
+
+
+void
+encrypt_crypt_files (int nfiles, char **files, strlist_t remusr)
+{
+  int rc = 0;
+
+  if (opt.outfile)
+    {
+      log_error(_("--output doesn't work for this command\n"));
+      return;        
+    }
+    
+  if (!nfiles)
+    {
+      char line[2048];
+      unsigned int lno = 0;
+      while ( fgets(line, DIM(line), stdin) )
+        {
+          lno++;
+          if (!*line || line[strlen(line)-1] != '\n')
+            {
+              log_error("input line %u too long or missing LF\n", lno);
+              return;
+            }
+          line[strlen(line)-1] = '\0';
+          print_file_status(STATUS_FILE_START, line, 2);
+          if ( (rc = encrypt_crypt(line, remusr, 0)) )
+            log_error("encryption of `%s' failed: %s\n",
+                      print_fname_stdin(line), g10_errstr(rc) );
+          write_status( STATUS_FILE_DONE );
+        }
+    }
+  else
+    {
+      while (nfiles--)
+        {
+          print_file_status(STATUS_FILE_START, *files, 2);
+          if ( (rc = encrypt_crypt(*files, remusr, 0)) )
+            log_error("encryption of `%s' failed: %s\n",
+                      print_fname_stdin(*files), g10_errstr(rc) );
+          write_status( STATUS_FILE_DONE );
+          files++;
+        }
+    }
+}