gnupg/g10/keygen.c

/* keygen.c - generate a key pair
 * Copyright (C) 1998, 1999, 2000, 2001, 2002 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <assert.h>
#include "util.h"
#include "main.h"
#include "packet.h"
#include "cipher.h"
#include "ttyio.h"
#include "options.h"
#include "keydb.h"
#include "trustdb.h"
#include "status.h"
#include "i18n.h"

#define MAX_PREFS 30 


enum para_name {
  pKEYTYPE,
  pKEYLENGTH,
  pKEYUSAGE,
  pSUBKEYTYPE,
  pSUBKEYLENGTH,
  pSUBKEYUSAGE,
  pNAMEREAL,
  pNAMEEMAIL,
  pNAMECOMMENT,
  pPREFERENCES,
  pREVOKER,
  pUSERID,
  pEXPIREDATE,
  pKEYEXPIRE, /* in n seconds */
  pSUBKEYEXPIRE, /* in n seconds */
  pPASSPHRASE,
  pPASSPHRASE_DEK,
  pPASSPHRASE_S2K
};

struct para_data_s {
    struct para_data_s *next;
    int lnr;
    enum para_name key;
    union {
        DEK *dek;
        STRING2KEY *s2k;
        u32 expire;
        unsigned int usage;
        struct revocation_key revkey;
        char value[1];
    } u;
};

struct output_control_s {
    int lnr;
    int dryrun;
    int use_files;
    struct {
	char  *fname;
	char  *newfname;
	IOBUF stream;
	armor_filter_context_t afx;
    } pub;
    struct {
	char  *fname;
	char  *newfname;
	IOBUF stream;
	armor_filter_context_t afx;
    } sec;
};


struct opaque_data_usage_and_pk {
    unsigned int usage;
    PKT_public_key *pk;
};


static int prefs_initialized = 0;
static byte sym_prefs[MAX_PREFS];
static int nsym_prefs;
static byte hash_prefs[MAX_PREFS];
static int nhash_prefs;
static byte zip_prefs[MAX_PREFS];
static int nzip_prefs;
static int mdc_available;

static void do_generate_keypair( struct para_data_s *para,
				 struct output_control_s *outctrl );
static int  write_keyblock( IOBUF out, KBNODE node );


static void
write_uid( KBNODE root, const char *s )
{
    PACKET *pkt = m_alloc_clear(sizeof *pkt );
    size_t n = strlen(s);

    pkt->pkttype = PKT_USER_ID;
    pkt->pkt.user_id = m_alloc_clear( sizeof *pkt->pkt.user_id + n - 1 );
    pkt->pkt.user_id->len = n;
    pkt->pkt.user_id->ref = 1;
    strcpy(pkt->pkt.user_id->name, s);
    add_kbnode( root, new_kbnode( pkt ) );
}

static void
do_add_key_flags (PKT_signature *sig, unsigned int use)
{
    byte buf[1];

    if (!use) 
        return;

    buf[0] = 0;
    if (use & PUBKEY_USAGE_SIG)
        buf[0] |= 0x01 | 0x02;
    if (use & PUBKEY_USAGE_ENC)
        buf[0] |= 0x04 | 0x08;
    build_sig_subpkt (sig, SIGSUBPKT_KEY_FLAGS, buf, 1);
}


int
keygen_add_key_expire( PKT_signature *sig, void *opaque )
{
    PKT_public_key *pk = opaque;
    byte buf[8];
    u32  u;

    if( pk->expiredate ) {
        if(pk->expiredate > pk->timestamp)
	  u= pk->expiredate - pk->timestamp;
	else
	  u= 0;

	buf[0] = (u >> 24) & 0xff;
	buf[1] = (u >> 16) & 0xff;
	buf[2] = (u >>	8) & 0xff;
	buf[3] = u & 0xff;
	build_sig_subpkt( sig, SIGSUBPKT_KEY_EXPIRE, buf, 4 );
    }
    else
      {
	/* Make sure we don't leave a key expiration subpacket lying
	   around */
	delete_sig_subpkt (sig->hashed, SIGSUBPKT_KEY_EXPIRE);
      }

    return 0;
}

static int
keygen_add_key_flags_and_expire (PKT_signature *sig, void *opaque)
{
    struct opaque_data_usage_and_pk *oduap = opaque;

    do_add_key_flags (sig, oduap->usage);
    return keygen_add_key_expire (sig, oduap->pk);
}

static int
set_one_pref (ulong val, int type, int (*cf)(int), byte *buf, int *nbuf)
{
    int i;

    if (cf (val)) {
        log_info (_("preference %c%lu is not valid\n"), type, val);
	if(type=='S' && val==CIPHER_ALGO_IDEA)
	  idea_cipher_warn(1);
        return -1;
    }
    for (i=0; i < *nbuf; i++ ) {
        if (buf[i] == val) {
            log_info (_("preference %c%lu duplicated\n"), type, val);
            return -1;
        }
    }
    if (*nbuf >= MAX_PREFS) {
        log_info (_("too many `%c' preferences\n"), type);
        return -1;
    }
    buf[(*nbuf)++] = val;
    return 0;
}


/*
 * Parse the supplied string and use it to set the standard preferences.
 * The String is expected to be in a forma like the one printed by "prefs",
 * something like:  "S10 S3 H3 H2 Z2 Z1".  Use NULL to set the default
 * preferences.
 * Returns: 0 = okay
 */
int
keygen_set_std_prefs (const char *string,int personal)
{
    byte sym[MAX_PREFS], hash[MAX_PREFS], zip[MAX_PREFS];
    int  nsym=0, nhash=0, nzip=0, mdc=1; /* mdc defaults on */
    ulong val;
    const char *s, *s2;
    int rc = 0;

    if (!string || !ascii_strcasecmp (string, "default")) {
      if (opt.def_preference_list)
	string=opt.def_preference_list;
      else if ( !check_cipher_algo(CIPHER_ALGO_IDEA) )
        string = "S7 S3 S2 S1 H2 H3 Z2 Z1";
      else
        string = "S7 S3 S2 H2 H3 Z2 Z1";

      /* If we have it, IDEA goes *after* 3DES so it won't be used
         unless we're encrypting along with a V3 key.  Ideally, we
         would only put the S1 preference in if the key was RSA and
         <=2048 bits, as that is what won't break PGP2, but that is
         difficult with the current code, and not really worth
         checking as a non-RSA <=2048 bit key wouldn't be usable by
         PGP2 anyway -dms */
    }
    else if (!ascii_strcasecmp (string, "none"))
        string = "";

    for (s=string; *s; s = s2) {
        if ((*s=='s' || *s == 'S') && isdigit(s[1]) ) {
            val = strtoul (++s, (char**)&s2, 10);
            if (set_one_pref (val, 'S', check_cipher_algo, sym, &nsym))
                rc = -1;
        }
        else if ((*s=='h' || *s == 'H') && isdigit(s[1]) ) {
            val = strtoul (++s, (char**)&s2, 10);
            if (set_one_pref (val, 'H', check_digest_algo, hash, &nhash))
                rc = -1;
        }
        else if ((*s=='z' || *s == 'Z') && isdigit(s[1]) ) {
            val = strtoul (++s, (char**)&s2, 10);
            if (set_one_pref (val, 'Z', check_compress_algo, zip, &nzip))
                rc = -1;
        }
	else if (ascii_strcasecmp(s,"mdc")==0) {
	  mdc=1;
	  s2=s+3;
	}
	else if (ascii_strcasecmp(s,"no-mdc")==0) {
	  mdc=0;
	  s2=s+6;
	}
        else if (isspace (*s))
            s2 = s+1;
        else {
            log_info (_("invalid character in preference string\n"));
            return -1;
        }
    }

    if (!rc)
      {
	if(personal)
	  {
	    if(personal==PREFTYPE_SYM)
	      {
		m_free(opt.personal_cipher_prefs);

		if(nsym==0)
		  opt.personal_cipher_prefs=NULL;
		else
		  {
		    int i;

		    opt.personal_cipher_prefs=
		      m_alloc(sizeof(prefitem_t *)*(nsym+1));

		    for (i=0; i<nsym; i++)
		      {
			opt.personal_cipher_prefs[i].type = PREFTYPE_SYM;
			opt.personal_cipher_prefs[i].value = sym[i];
		      }

		    opt.personal_cipher_prefs[i].type = PREFTYPE_NONE;
		    opt.personal_cipher_prefs[i].value = 0;
		  }
	      }
	    else if(personal==PREFTYPE_HASH)
	      {
		m_free(opt.personal_digest_prefs);

		if(nhash==0)
		  opt.personal_digest_prefs=NULL;
		else
		  {
		    int i;

		    opt.personal_digest_prefs=
		      m_alloc(sizeof(prefitem_t *)*(nhash+1));

		    for (i=0; i<nhash; i++)
		      {
			opt.personal_digest_prefs[i].type = PREFTYPE_HASH;
			opt.personal_digest_prefs[i].value = hash[i];
		      }

		    opt.personal_digest_prefs[i].type = PREFTYPE_NONE;
		    opt.personal_digest_prefs[i].value = 0;
		  }
	      }
	    else if(personal==PREFTYPE_ZIP)
	      {
		m_free(opt.personal_compress_prefs);

		if(nzip==0)
		  opt.personal_compress_prefs=NULL;
		else
		  {
		    int i;

		    opt.personal_compress_prefs=
		      m_alloc(sizeof(prefitem_t *)*(nzip+1));

		    for (i=0; i<nzip; i++)
		      {
			opt.personal_compress_prefs[i].type = PREFTYPE_ZIP;
			opt.personal_compress_prefs[i].value = zip[i];
		      }

		    opt.personal_compress_prefs[i].type = PREFTYPE_NONE;
		    opt.personal_compress_prefs[i].value = 0;
		  }
	      }
	  }
	else
	  {
	    memcpy (sym_prefs,  sym,  (nsym_prefs=nsym));
	    memcpy (hash_prefs, hash, (nhash_prefs=nhash));
	    memcpy (zip_prefs,  zip,  (nzip_prefs=nzip));
	    mdc_available = mdc;
	    prefs_initialized = 1;
	  }
      }

    return rc;
}


/* 
 * Return a printable list of preferences.  Caller must free.
 */
char *
keygen_get_std_prefs ()
{
    char *buf;
    int i;

    if (!prefs_initialized)
        keygen_set_std_prefs (NULL,0);

    buf = m_alloc ( MAX_PREFS*3*5 + 5 + 1);
    *buf = 0;
    for (i=0; i < nsym_prefs; i++ )
        sprintf (buf+strlen(buf), "S%d ", sym_prefs[i]);
    for (i=0; i < nhash_prefs; i++ )
        sprintf (buf+strlen(buf), "H%d ", hash_prefs[i]);
    for (i=0; i < nzip_prefs; i++ )
        sprintf (buf+strlen(buf), "Z%d ", zip_prefs[i]);

    if(mdc_available)
      sprintf(buf+strlen(buf),"[mdc]");
    else if (*buf) /* trim the trailing space */
      buf[strlen(buf)-1] = 0;

    return buf;
}


static void
add_feature_mdc (PKT_signature *sig,int enabled)
{
    const byte *s;
    size_t n;
    int i;
    char *buf;

    s = parse_sig_subpkt (sig->hashed, SIGSUBPKT_FEATURES, &n );
    /* Already set or cleared */
    if (s && n &&
	((enabled && (s[0] & 0x01)) || (!enabled && !(s[0] & 0x01))))
      return;

    if (!s || !n) { /* create a new one */
        n = 1;
        buf = m_alloc_clear (n);
    }
    else {
        buf = m_alloc (n);
        memcpy (buf, s, n);
    }

    if(enabled)
      buf[0] |= 0x01; /* MDC feature */
    else
      buf[0] &= ~0x01;

    /* Are there any bits set? */
    for(i=0;i<n;i++)
      if(buf[i]!=0)
	break;

    if(i==n)
      delete_sig_subpkt (sig->hashed, SIGSUBPKT_FEATURES);
    else
      build_sig_subpkt (sig, SIGSUBPKT_FEATURES, buf, n);

    m_free (buf);
}

int
keygen_upd_std_prefs( PKT_signature *sig, void *opaque )
{
    if (!prefs_initialized)
        keygen_set_std_prefs (NULL, 0);

    if (nsym_prefs) 
        build_sig_subpkt (sig, SIGSUBPKT_PREF_SYM, sym_prefs, nsym_prefs);
    else
      {
        delete_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_SYM);
        delete_sig_subpkt (sig->unhashed, SIGSUBPKT_PREF_SYM);
      }

    if (nhash_prefs)
        build_sig_subpkt (sig, SIGSUBPKT_PREF_HASH, hash_prefs, nhash_prefs);
    else
      {
	delete_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_HASH);
	delete_sig_subpkt (sig->unhashed, SIGSUBPKT_PREF_HASH);
      }

    if (nzip_prefs)
        build_sig_subpkt (sig, SIGSUBPKT_PREF_COMPR, zip_prefs, nzip_prefs);
    else
      {
        delete_sig_subpkt (sig->hashed, SIGSUBPKT_PREF_COMPR);
        delete_sig_subpkt (sig->unhashed, SIGSUBPKT_PREF_COMPR);
      }

    /* Make sure that the MDC feature flag is set if needed */
    add_feature_mdc (sig,mdc_available);

    return 0;
}


/****************
 * Add preference to the self signature packet.
 * This is only called for packets with version > 3.

 */
int
keygen_add_std_prefs( PKT_signature *sig, void *opaque )
{
    PKT_public_key *pk = opaque;
    byte buf[8];

    do_add_key_flags (sig, pk->pubkey_usage);
    keygen_add_key_expire( sig, opaque );
    keygen_upd_std_prefs (sig, opaque);

    buf[0] = 0x80; /* no modify - It is reasonable that a key holder
		    * has the possibility to reject signatures from users
		    * who are known to sign everything without any
		    * validation - so a signed key should be send
		    * to the holder who in turn can put it on a keyserver
		    */
    build_sig_subpkt( sig, SIGSUBPKT_KS_FLAGS, buf, 1 );

    return 0;
}

int
keygen_add_revkey(PKT_signature *sig, void *opaque)
{
  struct revocation_key *revkey=opaque;
  byte buf[2+MAX_FINGERPRINT_LEN];

  buf[0]=revkey->class;
  buf[1]=revkey->algid;
  memcpy(&buf[2],revkey->fpr,MAX_FINGERPRINT_LEN);

  build_sig_subpkt(sig,SIGSUBPKT_REV_KEY,buf,2+MAX_FINGERPRINT_LEN);

  /* All sigs with revocation keys set are nonrevocable */
  sig->flags.revocable=0;
  buf[0] = 0;
  build_sig_subpkt( sig, SIGSUBPKT_REVOCABLE, buf, 1 );

  parse_revkeys(sig);

  return 0;
}

static int
write_direct_sig( KBNODE root, KBNODE pub_root, PKT_secret_key *sk,
		  struct revocation_key *revkey )
{
    PACKET *pkt;
    PKT_signature *sig;
    int rc=0;
    KBNODE node;
    PKT_public_key *pk;

    if( opt.verbose )
	log_info(_("writing direct signature\n"));

    /* get the pk packet from the pub_tree */
    node = find_kbnode( pub_root, PKT_PUBLIC_KEY );
    if( !node )
	BUG();
    pk = node->pkt->pkt.public_key;

    /* we have to cache the key, so that the verification of the signature
     * creation is able to retrieve the public key */
    cache_public_key (pk);

    /* and make the signature */
    rc = make_keysig_packet(&sig,pk,NULL,NULL,sk,0x1F,0,0,0,0,
			    keygen_add_revkey,revkey);
    if( rc ) {
	log_error("make_keysig_packet failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    pkt = m_alloc_clear( sizeof *pkt );
    pkt->pkttype = PKT_SIGNATURE;
    pkt->pkt.signature = sig;
    add_kbnode( root, new_kbnode( pkt ) );
    return rc;
}

static int
write_selfsig( KBNODE root, KBNODE pub_root, PKT_secret_key *sk,
               unsigned int use )
{
    PACKET *pkt;
    PKT_signature *sig;
    PKT_user_id *uid;
    int rc=0;
    KBNODE node;
    PKT_public_key *pk;

    if( opt.verbose )
	log_info(_("writing self signature\n"));

    /* get the uid packet from the list */
    node = find_kbnode( root, PKT_USER_ID );
    if( !node )
	BUG(); /* no user id packet in tree */
    uid = node->pkt->pkt.user_id;
    /* get the pk packet from the pub_tree */
    node = find_kbnode( pub_root, PKT_PUBLIC_KEY );
    if( !node )
	BUG();
    pk = node->pkt->pkt.public_key;
    pk->pubkey_usage = use;
    /* we have to cache the key, so that the verification of the signature
     * creation is able to retrieve the public key */
    cache_public_key (pk);

    /* and make the signature */
    rc = make_keysig_packet( &sig, pk, uid, NULL, sk, 0x13, 0, 0, 0, 0,
        		     keygen_add_std_prefs, pk );
    if( rc ) {
	log_error("make_keysig_packet failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    pkt = m_alloc_clear( sizeof *pkt );
    pkt->pkttype = PKT_SIGNATURE;
    pkt->pkt.signature = sig;
    add_kbnode( root, new_kbnode( pkt ) );
    return rc;
}

static int
write_keybinding( KBNODE root, KBNODE pub_root, PKT_secret_key *sk,
                  unsigned int use )
{
    PACKET *pkt;
    PKT_signature *sig;
    int rc=0;
    KBNODE node;
    PKT_public_key *pk, *subpk;
    struct opaque_data_usage_and_pk oduap;

    if( opt.verbose )
	log_info(_("writing key binding signature\n"));

    /* get the pk packet from the pub_tree */
    node = find_kbnode( pub_root, PKT_PUBLIC_KEY );
    if( !node )
	BUG();
    pk = node->pkt->pkt.public_key;
    /* we have to cache the key, so that the verification of the signature
     * creation is able to retrieve the public key */
    cache_public_key (pk);
 
    /* find the last subkey */
    subpk = NULL;
    for(node=pub_root; node; node = node->next ) {
	if( node->pkt->pkttype == PKT_PUBLIC_SUBKEY )
	    subpk = node->pkt->pkt.public_key;
    }
    if( !subpk )
	BUG();

    /* and make the signature */
    oduap.usage = use;
    oduap.pk = subpk;
    rc = make_keysig_packet( &sig, pk, NULL, subpk, sk, 0x18, 0, 0, 0, 0,
        		     keygen_add_key_flags_and_expire, &oduap );
    if( rc ) {
	log_error("make_keysig_packet failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    pkt = m_alloc_clear( sizeof *pkt );
    pkt->pkttype = PKT_SIGNATURE;
    pkt->pkt.signature = sig;
    add_kbnode( root, new_kbnode( pkt ) );
    return rc;
}


static int
gen_elg(int algo, unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
	STRING2KEY *s2k, PKT_secret_key **ret_sk, u32 expireval )
{
    int rc;
    int i;
    PACKET *pkt;
    PKT_secret_key *sk;
    PKT_public_key *pk;
    MPI skey[4];
    MPI *factors;

    assert( is_ELGAMAL(algo) );

    if( nbits < 512 ) {
	nbits = 1024;
	log_info(_("keysize invalid; using %u bits\n"), nbits );
    }

    if( (nbits % 32) ) {
	nbits = ((nbits + 31) / 32) * 32;
	log_info(_("keysize rounded up to %u bits\n"), nbits );
    }

    rc = pubkey_generate( algo, nbits, skey, &factors );
    if( rc ) {
	log_error("pubkey_generate failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    sk = m_alloc_clear( sizeof *sk );
    pk = m_alloc_clear( sizeof *pk );
    sk->timestamp = pk->timestamp = make_timestamp();
    sk->version = pk->version = 4;
    if( expireval ) {
	sk->expiredate = pk->expiredate = sk->timestamp + expireval;
    }
    sk->pubkey_algo = pk->pubkey_algo = algo;
		       pk->pkey[0] = mpi_copy( skey[0] );
		       pk->pkey[1] = mpi_copy( skey[1] );
		       pk->pkey[2] = mpi_copy( skey[2] );
    sk->skey[0] = skey[0];
    sk->skey[1] = skey[1];
    sk->skey[2] = skey[2];
    sk->skey[3] = skey[3];
    sk->is_protected = 0;
    sk->protect.algo = 0;

    sk->csum = checksum_mpi( sk->skey[3] );
    if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
	*ret_sk = copy_secret_key( NULL, sk );

    if( dek ) {
	sk->protect.algo = dek->algo;
	sk->protect.s2k = *s2k;
	rc = protect_secret_key( sk, dek );
	if( rc ) {
	    log_error("protect_secret_key failed: %s\n", g10_errstr(rc) );
	    free_public_key(pk);
	    free_secret_key(sk);
	    return rc;
	}
    }

    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_PUBLIC_KEY : PKT_PUBLIC_SUBKEY;
    pkt->pkt.public_key = pk;
    add_kbnode(pub_root, new_kbnode( pkt ));

    /* don't know whether it makes sense to have the factors, so for now
     * we store them in the secret keyring (but they are not secret) */
    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_SECRET_KEY : PKT_SECRET_SUBKEY;
    pkt->pkt.secret_key = sk;
    add_kbnode(sec_root, new_kbnode( pkt ));
    for(i=0; factors[i]; i++ )
	add_kbnode( sec_root,
		    make_mpi_comment_node("#:ELG_factor:", factors[i] ));

    return 0;
}


/****************
 * Generate a DSA key
 */
static int
gen_dsa(unsigned int nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
	    STRING2KEY *s2k, PKT_secret_key **ret_sk, u32 expireval )
{
    int rc;
    int i;
    PACKET *pkt;
    PKT_secret_key *sk;
    PKT_public_key *pk;
    MPI skey[5];
    MPI *factors;

    if( nbits > 1024 || nbits < 512 ) {
	nbits = 1024;
	log_info(_("keysize invalid; using %u bits\n"), nbits );
    }

    if( (nbits % 64) ) {
	nbits = ((nbits + 63) / 64) * 64;
	log_info(_("keysize rounded up to %u bits\n"), nbits );
    }

    rc = pubkey_generate( PUBKEY_ALGO_DSA, nbits, skey, &factors );
    if( rc ) {
	log_error("pubkey_generate failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    sk = m_alloc_clear( sizeof *sk );
    pk = m_alloc_clear( sizeof *pk );
    sk->timestamp = pk->timestamp = make_timestamp();
    sk->version = pk->version = 4;
    if( expireval ) {
	sk->expiredate = pk->expiredate = sk->timestamp + expireval;
    }
    sk->pubkey_algo = pk->pubkey_algo = PUBKEY_ALGO_DSA;
		       pk->pkey[0] = mpi_copy( skey[0] );
		       pk->pkey[1] = mpi_copy( skey[1] );
		       pk->pkey[2] = mpi_copy( skey[2] );
		       pk->pkey[3] = mpi_copy( skey[3] );
    sk->skey[0] = skey[0];
    sk->skey[1] = skey[1];
    sk->skey[2] = skey[2];
    sk->skey[3] = skey[3];
    sk->skey[4] = skey[4];
    sk->is_protected = 0;
    sk->protect.algo = 0;

    sk->csum = checksum_mpi ( sk->skey[4] );
    if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
	*ret_sk = copy_secret_key( NULL, sk );

    if( dek ) {
	sk->protect.algo = dek->algo;
	sk->protect.s2k = *s2k;
	rc = protect_secret_key( sk, dek );
	if( rc ) {
	    log_error("protect_secret_key failed: %s\n", g10_errstr(rc) );
	    free_public_key(pk);
	    free_secret_key(sk);
	    return rc;
	}
    }

    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_PUBLIC_KEY : PKT_PUBLIC_SUBKEY;
    pkt->pkt.public_key = pk;
    add_kbnode(pub_root, new_kbnode( pkt ));

    /* don't know whether it makes sense to have the factors, so for now
     * we store them in the secret keyring (but they are not secret)
     * p = 2 * q * f1 * f2 * ... * fn
     * We store only f1 to f_n-1;  fn can be calculated because p and q
     * are known.
     */
    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_SECRET_KEY : PKT_SECRET_SUBKEY;
    pkt->pkt.secret_key = sk;
    add_kbnode(sec_root, new_kbnode( pkt ));
    for(i=1; factors[i]; i++ )	/* the first one is q */
	add_kbnode( sec_root,
		    make_mpi_comment_node("#:DSA_factor:", factors[i] ));

    return 0;
}


/* 
 * Generate an RSA key.
 */
static int
gen_rsa(int algo, unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
	STRING2KEY *s2k, PKT_secret_key **ret_sk, u32 expireval )
{
    int rc;
    PACKET *pkt;
    PKT_secret_key *sk;
    PKT_public_key *pk;
    MPI skey[6];
    MPI *factors;

    assert( is_RSA(algo) );

    if( nbits < 1024 ) {
	nbits = 1024;
	log_info(_("keysize invalid; using %u bits\n"), nbits );
    }

    if( (nbits % 32) ) {
	nbits = ((nbits + 31) / 32) * 32;
	log_info(_("keysize rounded up to %u bits\n"), nbits );
    }

    rc = pubkey_generate( algo, nbits, skey, &factors );
    if( rc ) {
	log_error("pubkey_generate failed: %s\n", g10_errstr(rc) );
	return rc;
    }

    sk = m_alloc_clear( sizeof *sk );
    pk = m_alloc_clear( sizeof *pk );
    sk->timestamp = pk->timestamp = make_timestamp();
    sk->version = pk->version = 4;
    if( expireval ) {
	sk->expiredate = pk->expiredate = sk->timestamp + expireval;
    }
    sk->pubkey_algo = pk->pubkey_algo = algo;
		       pk->pkey[0] = mpi_copy( skey[0] );
		       pk->pkey[1] = mpi_copy( skey[1] );
    sk->skey[0] = skey[0];
    sk->skey[1] = skey[1];
    sk->skey[2] = skey[2];
    sk->skey[3] = skey[3];
    sk->skey[4] = skey[4];
    sk->skey[5] = skey[5];
    sk->is_protected = 0;
    sk->protect.algo = 0;

    sk->csum  = checksum_mpi (sk->skey[2] );
    sk->csum += checksum_mpi (sk->skey[3] );
    sk->csum += checksum_mpi (sk->skey[4] );
    sk->csum += checksum_mpi (sk->skey[5] );
    if( ret_sk ) /* not a subkey: return an unprotected version of the sk */
	*ret_sk = copy_secret_key( NULL, sk );

    if( dek ) {
	sk->protect.algo = dek->algo;
	sk->protect.s2k = *s2k;
	rc = protect_secret_key( sk, dek );
	if( rc ) {
	    log_error("protect_secret_key failed: %s\n", g10_errstr(rc) );
	    free_public_key(pk);
	    free_secret_key(sk);
	    return rc;
	}
    }

    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_PUBLIC_KEY : PKT_PUBLIC_SUBKEY;
    pkt->pkt.public_key = pk;
    add_kbnode(pub_root, new_kbnode( pkt ));

    pkt = m_alloc_clear(sizeof *pkt);
    pkt->pkttype = ret_sk ? PKT_SECRET_KEY : PKT_SECRET_SUBKEY;
    pkt->pkt.secret_key = sk;
    add_kbnode(sec_root, new_kbnode( pkt ));

    return 0;
}


/****************
 * check valid days:
 * return 0 on error or the multiplier
 */
static int
check_valid_days( const char *s )
{
    if( !isdigit(*s) )
	return 0;
    for( s++; *s; s++)
	if( !isdigit(*s) )
	    break;
    if( !*s )
	return 1;
    if( s[1] )
	return 0; /* e.g. "2323wc" */
    if( *s == 'd' || *s == 'D' )
	return 1;
    if( *s == 'w' || *s == 'W' )
	return 7;
    if( *s == 'm' || *s == 'M' )
	return 30;
    if( *s == 'y' || *s == 'Y' )
	return 365;
    return 0;
}


/****************
 * Returns: 0 to create both a DSA and a ElGamal key.
 *          and only if key flags are to be written the desired usage.
 */
static int
ask_algo (int addmode, unsigned int *r_usage)
{
    char *answer;
    int algo;

    *r_usage = 0;
    tty_printf(_("Please select what kind of key you want:\n"));
    if( !addmode )
	tty_printf(_("   (%d) DSA and ElGamal (default)\n"), 1 );
    tty_printf(    _("   (%d) DSA (sign only)\n"), 2 );
    if( addmode )
	tty_printf(    _("   (%d) ElGamal (encrypt only)\n"), 3 );
    if (opt.expert)
        tty_printf(    _("   (%d) ElGamal (sign and encrypt)\n"), 4 );
    tty_printf(    _("   (%d) RSA (sign only)\n"), 5 );
    if (addmode)
        tty_printf(    _("   (%d) RSA (encrypt only)\n"), 6 );
    if (opt.expert)
      tty_printf(    _("   (%d) RSA (sign and encrypt)\n"), 7 );

    for(;;) {
	answer = cpr_get("keygen.algo",_("Your selection? "));
	cpr_kill_prompt();
	algo = *answer? atoi(answer): 1;
	m_free(answer);
	if( algo == 1 && !addmode ) {
	    algo = 0;	/* create both keys */
	    break;
	}
	else if( algo == 7 && opt.expert ) {
	    algo = PUBKEY_ALGO_RSA;
	    *r_usage = PUBKEY_USAGE_ENC | PUBKEY_USAGE_SIG;
	    break;
	}
	else if( algo == 6 && addmode ) {
	    algo = PUBKEY_ALGO_RSA;
            *r_usage = PUBKEY_USAGE_ENC;
	    break;
	}
	else if( algo == 5 ) {
	    algo = PUBKEY_ALGO_RSA;
            *r_usage = PUBKEY_USAGE_SIG;
	    break;
	}
	else if( algo == 4 && opt.expert)
	  {
	    tty_printf(_(
"The use of this algorithm is only supported by GnuPG.  You will not be\n"
"able to use this key to communicate with PGP users.  This algorithm is also\n"
"very slow, and may not be as secure as the other choices.\n"));

	    if( cpr_get_answer_is_yes("keygen.algo.elg_se",
				      _("Create anyway? ")))
	      {
		algo = PUBKEY_ALGO_ELGAMAL;
		break;
	      }
	}
	else if( algo == 3 && addmode ) {
	    algo = PUBKEY_ALGO_ELGAMAL_E;
	    break;
	}
	else if( algo == 2 ) {
	    algo = PUBKEY_ALGO_DSA;
	    break;
	}
	else
	    tty_printf(_("Invalid selection.\n"));
    }
    return algo;
}


static unsigned
ask_keysize( int algo )
{
    char *answer;
    unsigned nbits;

    if (algo != PUBKEY_ALGO_DSA && algo != PUBKEY_ALGO_RSA) {
        tty_printf (_("About to generate a new %s keypair.\n"
                      "              minimum keysize is  768 bits\n"
                      "              default keysize is 1024 bits\n"
                      "    highest suggested keysize is 2048 bits\n"),
                    pubkey_algo_to_string(algo) );
    }

    for(;;) {
	answer = cpr_get("keygen.size",
			  _("What keysize do you want? (1024) "));
	cpr_kill_prompt();
	nbits = *answer? atoi(answer): 1024;
	m_free(answer);
	if( algo == PUBKEY_ALGO_DSA && (nbits < 512 || nbits > 1024) )
	    tty_printf(_("DSA only allows keysizes from 512 to 1024\n"));
	else if( algo == PUBKEY_ALGO_RSA && nbits < 1024 )
	    tty_printf(_("keysize too small;"
			 " 1024 is smallest value allowed for RSA.\n"));
	else if( nbits < 768 )
	    tty_printf(_("keysize too small;"
			 " 768 is smallest value allowed.\n"));
	else if( nbits > 4096 ) {
	    /* It is ridiculous and an annoyance to use larger key sizes!
	     * GnuPG can handle much larger sizes; but it takes an eternity
	     * to create such a key (but less than the time the Sirius
	     * Computer Corporation needs to process one of the usual
	     * complaints) and {de,en}cryption although needs some time.
	     * So, before you complain about this limitation, I suggest that
	     * you start a discussion with Marvin about this theme and then
	     * do whatever you want. */
	    tty_printf(_("keysize too large; %d is largest value allowed.\n"),
									 4096);
	}
	else if( nbits > 2048 && !cpr_enabled() ) {
	    tty_printf(
		_("Keysizes larger than 2048 are not suggested because\n"
		  "computations take REALLY long!\n"));
	    if( cpr_get_answer_is_yes("keygen.size.huge.okay",_(
			"Are you sure that you want this keysize? ")) ) {
		tty_printf(_("Okay, but keep in mind that your monitor "
			     "and keyboard radiation is also very vulnerable "
			     "to attacks!\n"));
		break;
	    }
	}
	else
	    break;
    }
    tty_printf(_("Requested keysize is %u bits\n"), nbits );
    if( algo == PUBKEY_ALGO_DSA && (nbits % 64) ) {
	nbits = ((nbits + 63) / 64) * 64;
	tty_printf(_("rounded up to %u bits\n"), nbits );
    }
    else if( (nbits % 32) ) {
	nbits = ((nbits + 31) / 32) * 32;
	tty_printf(_("rounded up to %u bits\n"), nbits );
    }
    return nbits;
}


/****************
 * Parse an expire string and return it's value in days.
 * Returns -1 on error.
 */
static int
parse_expire_string( const char *string )
{
    int mult;
    u32 abs_date=0;
    u32 curtime = make_timestamp();
    int valid_days;

    if( !*string )
	valid_days = 0;
    else if( (abs_date = scan_isodatestr(string)) && abs_date > curtime ) {
	/* This calculation is not perfectly okay because we
	 * are later going to simply multiply by 86400 and don't
	 * correct for leapseconds.  A solution would be to change
	 * the whole implemenation to work with dates and not intervals
	 * which are required for v3 keys.
	 */
	valid_days = abs_date/86400-curtime/86400+1;
    }
    else if( (mult=check_valid_days(string)) ) {
	valid_days = atoi(string) * mult;
	if( valid_days < 0 || valid_days > 39447 )
	    valid_days = 0;
    }
    else {
	valid_days = -1;
    }
    return valid_days;
}

/* object == 0 for a key, and 1 for a sig */
u32
ask_expire_interval(int object)
{
    char *answer;
    int valid_days=0;
    u32 interval = 0;

    switch(object)
      {
      case 0:
	tty_printf(_("Please specify how long the key should be valid.\n"
		     "         0 = key does not expire\n"
		     "      <n>  = key expires in n days\n"
		     "      <n>w = key expires in n weeks\n"
		     "      <n>m = key expires in n months\n"
		     "      <n>y = key expires in n years\n"));
	break;

      case 1:
	tty_printf(_("Please specify how long the signature should be valid.\n"
		     "         0 = signature does not expire\n"
		     "      <n>  = signature expires in n days\n"
		     "      <n>w = signature expires in n weeks\n"
		     "      <n>m = signature expires in n months\n"
		     "      <n>y = signature expires in n years\n"));
	break;

      default:
	BUG();
      }

    /* Note: The elgamal subkey for DSA has no expiration date because
     * it must be signed with the DSA key and this one has the expiration
     * date */

    answer = NULL;
    for(;;) {
	u32 curtime=make_timestamp();

	m_free(answer);
	if(object==0)
	  answer = cpr_get("keygen.valid",_("Key is valid for? (0) "));
	else
	  answer = cpr_get("siggen.valid",_("Signature is valid for? (0) "));
	cpr_kill_prompt();
	trim_spaces(answer);
	valid_days = parse_expire_string( answer );
	if( valid_days < 0 ) {
	    tty_printf(_("invalid value\n"));
	    continue;
	}

	if( !valid_days ) {
	    tty_printf(_("%s does not expire at all\n"),
		       object==0?"Key":"Signature");
	    interval = 0;
	}
	else {
	    interval = valid_days * 86400L;
	    /* print the date when the key expires */
	    tty_printf(_("%s expires at %s\n"),
		        object==0?"Key":"Signature",
			asctimestamp((ulong)(curtime + interval) ) );
            /* FIXME: This check yields warning on alhas:
               write a configure check and to this check here only for 32 bit machines */
	    if( (time_t)((ulong)(curtime+interval)) < 0 )
		tty_printf(_("Your system can't display dates beyond 2038.\n"
		    "However, it will be correctly handled up to 2106.\n"));
	}

	if( cpr_enabled() || cpr_get_answer_is_yes("keygen.valid.okay",
					    _("Is this correct (y/n)? ")) )
	    break;
    }
    m_free(answer);
    return interval;
}

u32
ask_expiredate()
{
    u32 x = ask_expire_interval(0);
    return x? make_timestamp() + x : 0;
}

static int
has_invalid_email_chars( const char *s )
{
    int at_seen=0;
    static char valid_chars[] = "01234567890_-."
				"abcdefghijklmnopqrstuvwxyz"
				"ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    for( ; *s; s++ ) {
	if( *s & 0x80 )
	    return 1;
	if( *s == '@' )
	    at_seen=1;
	else if( !at_seen && !( !!strchr( valid_chars, *s ) || *s == '+' ) )
	    return 1;
	else if( at_seen && !strchr( valid_chars, *s ) )
	    return 1;
    }
    return 0;
}


static char *
ask_user_id( int mode )
{
    char *answer;
    char *aname, *acomment, *amail, *uid;

    if( !mode )
	tty_printf( _("\n"
"You need a User-ID to identify your key; the software constructs the user id\n"
"from Real Name, Comment and Email Address in this form:\n"
"    \"Heinrich Heine (Der Dichter) <heinrichh@duesseldorf.de>\"\n\n") );
    uid = aname = acomment = amail = NULL;
    for(;;) {
	char *p;
	int fail=0;

	if( !aname ) {
	    for(;;) {
		m_free(aname);
		aname = cpr_get("keygen.name",_("Real name: "));
		trim_spaces(aname);
		cpr_kill_prompt();

		if( opt.allow_freeform_uid )
		    break;

		if( strpbrk( aname, "<>" ) )
		    tty_printf(_("Invalid character in name\n"));
		else if( isdigit(*aname) )
		    tty_printf(_("Name may not start with a digit\n"));
		else if( strlen(aname) < 5 )
		    tty_printf(_("Name must be at least 5 characters long\n"));
		else
		    break;
	    }
	}
	if( !amail ) {
	    for(;;) {
		m_free(amail);
		amail = cpr_get("keygen.email",_("Email address: "));
		trim_spaces(amail);
		cpr_kill_prompt();
		if( !*amail )
		    break;   /* no email address is okay */
		else if( has_invalid_email_chars(amail)
			 || string_count_chr(amail,'@') != 1
			 || *amail == '@'
			 || amail[strlen(amail)-1] == '@'
			 || amail[strlen(amail)-1] == '.'
			 || strstr(amail, "..") )
		    tty_printf(_("Not a valid email address\n"));
		else
		    break;
	    }
	}
	if( !acomment ) {
	    for(;;) {
		m_free(acomment);
		acomment = cpr_get("keygen.comment",_("Comment: "));
		trim_spaces(acomment);
		cpr_kill_prompt();
		if( !*acomment )
		    break;   /* no comment is okay */
		else if( strpbrk( acomment, "()" ) )
		    tty_printf(_("Invalid character in comment\n"));
		else
		    break;
	    }
	}


	m_free(uid);
	uid = p = m_alloc(strlen(aname)+strlen(amail)+strlen(acomment)+12+10);
	p = stpcpy(p, aname );
	if( *acomment )
	    p = stpcpy(stpcpy(stpcpy(p," ("), acomment),")");
	if( *amail )
	    p = stpcpy(stpcpy(stpcpy(p," <"), amail),">");

	/* append a warning if we do not have dev/random
	 * or it is switched into  quick testmode */
	if( quick_random_gen(-1) )
	    strcpy(p, " (INSECURE!)" );

	/* print a note in case that UTF8 mapping has to be done */
	for(p=uid; *p; p++ ) {
	    if( *p & 0x80 ) {
		tty_printf(_("You are using the `%s' character set.\n"),
			   get_native_charset() );
		break;
	    }
	}

	tty_printf(_("You selected this USER-ID:\n    \"%s\"\n\n"), uid);
	/* fixme: add a warning if this user-id already exists */
	if( !*amail && (strchr( aname, '@' ) || strchr( acomment, '@'))) {
	    fail = 1;
	    tty_printf(_("Please don't put the email address "
			  "into the real name or the comment\n") );
	}

	for(;;) {
	    const char *ansstr = _("NnCcEeOoQq");

	    if( strlen(ansstr) != 10 )
		BUG();
	    if( cpr_enabled() ) {
		answer = m_strdup(ansstr+6);
		answer[1] = 0;
	    }
	    else {
		answer = cpr_get("keygen.userid.cmd", fail?
		  _("Change (N)ame, (C)omment, (E)mail or (Q)uit? ") :
		  _("Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? "));
		cpr_kill_prompt();
	    }
	    if( strlen(answer) > 1 )
		;
	    else if( *answer == ansstr[0] || *answer == ansstr[1] ) {
		m_free(aname); aname = NULL;
		break;
	    }
	    else if( *answer == ansstr[2] || *answer == ansstr[3] ) {
		m_free(acomment); acomment = NULL;
		break;
	    }
	    else if( *answer == ansstr[4] || *answer == ansstr[5] ) {
		m_free(amail); amail = NULL;
		break;
	    }
	    else if( *answer == ansstr[6] || *answer == ansstr[7] ) {
		if( fail ) {
		    tty_printf(_("Please correct the error first\n"));
		}
		else {
		    m_free(aname); aname = NULL;
		    m_free(acomment); acomment = NULL;
		    m_free(amail); amail = NULL;
		    break;
		}
	    }
	    else if( *answer == ansstr[8] || *answer == ansstr[9] ) {
		m_free(aname); aname = NULL;
		m_free(acomment); acomment = NULL;
		m_free(amail); amail = NULL;
		m_free(uid); uid = NULL;
		break;
	    }
	    m_free(answer);
	}
	m_free(answer);
	if( !amail && !acomment && !amail )
	    break;
	m_free(uid); uid = NULL;
    }
    if( uid ) {
	char *p = native_to_utf8( uid );
	m_free( uid );
	uid = p;
    }
    return uid;
}


static DEK *
ask_passphrase( STRING2KEY **ret_s2k )
{
    DEK *dek = NULL;
    STRING2KEY *s2k;
    const char *errtext = NULL;

    tty_printf(_("You need a Passphrase to protect your secret key.\n\n") );

    s2k = m_alloc_secure( sizeof *s2k );
    for(;;) {
	s2k->mode = opt.s2k_mode;
	s2k->hash_algo = opt.s2k_digest_algo;
	dek = passphrase_to_dek( NULL, 0, opt.s2k_cipher_algo, s2k,2,errtext);
	if( !dek ) {
	    errtext = _("passphrase not correctly repeated; try again");
	    tty_printf(_("%s.\n"), errtext);
	}
	else if( !dek->keylen ) {
	    m_free(dek); dek = NULL;
	    m_free(s2k); s2k = NULL;
	    tty_printf(_(
	    "You don't want a passphrase - this is probably a *bad* idea!\n"
	    "I will do it anyway.  You can change your passphrase at any time,\n"
	    "using this program with the option \"--edit-key\".\n\n"));
	    break;
	}
	else
	    break; /* okay */
    }
    *ret_s2k = s2k;
    return dek;
}


static int
do_create( int algo, unsigned int nbits, KBNODE pub_root, KBNODE sec_root,
	   DEK *dek, STRING2KEY *s2k, PKT_secret_key **sk, u32 expiredate )
{
    int rc=0;

    if( !opt.batch )
	tty_printf(_(
"We need to generate a lot of random bytes. It is a good idea to perform\n"
"some other action (type on the keyboard, move the mouse, utilize the\n"
"disks) during the prime generation; this gives the random number\n"
"generator a better chance to gain enough entropy.\n") );

    if( algo == PUBKEY_ALGO_ELGAMAL || algo == PUBKEY_ALGO_ELGAMAL_E )
	rc = gen_elg(algo, nbits, pub_root, sec_root, dek, s2k, sk, expiredate);
    else if( algo == PUBKEY_ALGO_DSA )
	rc = gen_dsa(nbits, pub_root, sec_root, dek, s2k, sk, expiredate);
    else if( algo == PUBKEY_ALGO_RSA )
	rc = gen_rsa(algo, nbits, pub_root, sec_root, dek, s2k, sk, expiredate);
    else
	BUG();

  #ifdef ENABLE_COMMENT_PACKETS
    if( !rc ) {
	add_kbnode( pub_root,
		make_comment_node("#created by GNUPG v" VERSION " ("
					    PRINTABLE_OS_NAME ")"));
	add_kbnode( sec_root,
		make_comment_node("#created by GNUPG v" VERSION " ("
					    PRINTABLE_OS_NAME ")"));
    }
  #endif
    return rc;
}


/****************
 * Generate a new user id packet, or return NULL if canceled
 */
PKT_user_id *
generate_user_id()
{
    PKT_user_id *uid;
    char *p;
    size_t n;

    p = ask_user_id( 1 );
    if( !p )
	return NULL;
    n = strlen(p);
    uid = m_alloc_clear( sizeof *uid + n - 1 );
    uid->len = n;
    strcpy(uid->name, p);
    uid->ref = 1;
    return uid;
}


static void
release_parameter_list( struct para_data_s *r )
{
    struct para_data_s *r2;

    for( ; r ; r = r2 ) {
	r2 = r->next;
	if( r->key == pPASSPHRASE_DEK )
	    m_free( r->u.dek );
	else if( r->key == pPASSPHRASE_S2K )
	    m_free( r->u.s2k );

	m_free(r);
    }
}

static struct para_data_s *
get_parameter( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r;

    for( r = para; r && r->key != key; r = r->next )
	;
    return r;
}

static const char *
get_parameter_value( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return (r && *r->u.value)? r->u.value : NULL;
}

static int
get_parameter_algo( struct para_data_s *para, enum para_name key )
{
    int i;
    struct para_data_s *r = get_parameter( para, key );
    if( !r )
	return -1;
    if( isdigit( *r->u.value ) )
	i = atoi( r->u.value );
    else
        i = string_to_pubkey_algo( r->u.value );
    if (i == PUBKEY_ALGO_RSA_E || i == PUBKEY_ALGO_RSA_S)
      i = 0; /* we don't want to allow generation of these algorithms */
    return i;
}

/* 
 * parse the usage parameter and set the keyflags.  Return true on error.
 */
static int
parse_parameter_usage (const char *fname,
                       struct para_data_s *para, enum para_name key)
{
    struct para_data_s *r = get_parameter( para, key );
    char *p, *pn;
    unsigned int use;

    if( !r )
	return 0; /* none (this is an optional parameter)*/
    
    use = 0;
    pn = r->u.value;
    while ( (p = strsep (&pn, " \t,")) ) {
        if ( !*p)
            ;
        else if ( !ascii_strcasecmp (p, "sign") )
            use |= PUBKEY_USAGE_SIG;
        else if ( !ascii_strcasecmp (p, "encrypt") )
            use |= PUBKEY_USAGE_ENC;
        else {
            log_error("%s:%d: invalid usage list\n", fname, r->lnr );
            return -1; /* error */
        }
    }
    r->u.usage = use;
    return 0;
}

static int
parse_revocation_key (const char *fname,
		      struct para_data_s *para, enum para_name key)
{
  struct para_data_s *r = get_parameter( para, key );
  struct revocation_key revkey;
  char *pn;
  int i;

  if( !r )
    return 0; /* none (this is an optional parameter) */

  pn = r->u.value;

  revkey.class=0x80;
  revkey.algid=atoi(pn);
  if(!revkey.algid)
    goto fail;

  /* Skip to the fpr */
  while(*pn && *pn!=':')
    pn++;

  if(*pn!=':')
    goto fail;

  pn++;

  for(i=0;i<MAX_FINGERPRINT_LEN && *pn;i++,pn+=2)
    {
      int c=hextobyte(pn);
      if(c==-1)
	goto fail;

      revkey.fpr[i]=c;
    }

  /* skip to the tag */
  while(*pn && *pn!='s' && *pn!='S')
    pn++;

  if(ascii_strcasecmp(pn,"sensitive")==0)
    revkey.class|=0x40;

  memcpy(&r->u.revkey,&revkey,sizeof(struct revocation_key));

  return 0;

  fail:
  log_error("%s:%d: invalid revocation key\n", fname, r->lnr );
  return -1; /* error */
}


static u32
get_parameter_u32( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );

    if( !r )
	return 0;
    if( r->key == pKEYEXPIRE || r->key == pSUBKEYEXPIRE )
	return r->u.expire;
    if( r->key == pKEYUSAGE || r->key == pSUBKEYUSAGE )
	return r->u.usage;

    return (unsigned int)strtoul( r->u.value, NULL, 10 );
}

static unsigned int
get_parameter_uint( struct para_data_s *para, enum para_name key )
{
    return get_parameter_u32( para, key );
}

static DEK *
get_parameter_dek( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return r? r->u.dek : NULL;
}

static STRING2KEY *
get_parameter_s2k( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return r? r->u.s2k : NULL;
}

static struct revocation_key *
get_parameter_revkey( struct para_data_s *para, enum para_name key )
{
    struct para_data_s *r = get_parameter( para, key );
    return r? &r->u.revkey : NULL;
}

static int
proc_parameter_file( struct para_data_s *para, const char *fname,
                     struct output_control_s *outctrl )
{
    struct para_data_s *r;
    const char *s1, *s2, *s3;
    size_t n;
    char *p;
    int i;

    /* check that we have all required parameters */
    assert( get_parameter( para, pKEYTYPE ) );
    i = get_parameter_algo( para, pKEYTYPE );
    if( i < 1 || check_pubkey_algo2( i, PUBKEY_USAGE_SIG ) ) {
	r = get_parameter( para, pKEYTYPE );
	log_error("%s:%d: invalid algorithm\n", fname, r->lnr );
	return -1;
    }

    if (parse_parameter_usage (fname, para, pKEYUSAGE))
        return -1;

    i = get_parameter_algo( para, pSUBKEYTYPE );
    if( i > 0 && check_pubkey_algo( i ) ) {
	r = get_parameter( para, pSUBKEYTYPE );
	log_error("%s:%d: invalid algorithm\n", fname, r->lnr );
	return -1;
    }
    if (i > 0 && parse_parameter_usage (fname, para, pSUBKEYUSAGE))
        return -1;


    if( !get_parameter_value( para, pUSERID ) ) {
	/* create the formatted user ID */
	s1 = get_parameter_value( para, pNAMEREAL );
	s2 = get_parameter_value( para, pNAMECOMMENT );
	s3 = get_parameter_value( para, pNAMEEMAIL );
	if( s1 || s2 || s3 ) {
	    n = (s1?strlen(s1):0) + (s2?strlen(s2):0) + (s3?strlen(s3):0);
	    r = m_alloc_clear( sizeof *r + n + 20 );
	    r->key = pUSERID;
	    p = r->u.value;
	    if( s1 )
		p = stpcpy(p, s1 );
	    if( s2 )
		p = stpcpy(stpcpy(stpcpy(p," ("), s2 ),")");
	    if( s3 )
		p = stpcpy(stpcpy(stpcpy(p," <"), s3 ),">");
	    r->next = para;
	    para = r;
	}
    }

    /* Set preferences, if any. */
    keygen_set_std_prefs(get_parameter_value( para, pPREFERENCES ), 0);

    /* Set revoker, if any. */
    if (parse_revocation_key (fname, para, pREVOKER))
      return -1;

    /* make DEK and S2K from the Passphrase */
    r = get_parameter( para, pPASSPHRASE );
    if( r && *r->u.value ) {
	/* we have a plain text passphrase - create a DEK from it.
	 * It is a little bit ridiculous to keep it ih secure memory
	 * but becuase we do this alwasy, why not here */
	STRING2KEY *s2k;
	DEK *dek;

	s2k = m_alloc_secure( sizeof *s2k );
	s2k->mode = opt.s2k_mode;
	s2k->hash_algo = opt.s2k_digest_algo;
	set_next_passphrase( r->u.value );
	dek = passphrase_to_dek( NULL, 0, opt.s2k_cipher_algo, s2k, 2, NULL );
	set_next_passphrase( NULL );
	assert( dek );
	memset( r->u.value, 0, strlen(r->u.value) );

	r = m_alloc_clear( sizeof *r );
	r->key = pPASSPHRASE_S2K;
	r->u.s2k = s2k;
	r->next = para;
	para = r;
	r = m_alloc_clear( sizeof *r );
	r->key = pPASSPHRASE_DEK;
	r->u.dek = dek;
	r->next = para;
	para = r;
    }

    /* make KEYEXPIRE from Expire-Date */
    r = get_parameter( para, pEXPIREDATE );
    if( r && *r->u.value ) {
	i = parse_expire_string( r->u.value );
	if( i < 0 ) {
	    log_error("%s:%d: invalid expire date\n", fname, r->lnr );
	    return -1;
	}
	r->u.expire = i * 86400L;
	r->key = pKEYEXPIRE;  /* change hat entry */
	/* also set it for the subkey */
	r = m_alloc_clear( sizeof *r + 20 );
	r->key = pSUBKEYEXPIRE;
	r->u.expire = i * 86400L;
	r->next = para;
	para = r;
    }

    if( !!outctrl->pub.newfname ^ !!outctrl->sec.newfname ) {
	log_error("%s:%d: only one ring name is set\n", fname, outctrl->lnr );
	return -1;
    }

    do_generate_keypair( para, outctrl );
    return 0;
}


/****************
 * Kludge to allow non interactive key generation controlled
 * by a parameter file (which currently is only stdin)
 * Note, that string parameters are expected to be in UTF-8
 */
static void
read_parameter_file( const char *fname )
{
    static struct { const char *name;
		    enum para_name key;
    } keywords[] = {
	{ "Key-Type",       pKEYTYPE},
	{ "Key-Length",     pKEYLENGTH },
	{ "Key-Usage",      pKEYUSAGE },
	{ "Subkey-Type",    pSUBKEYTYPE },
	{ "Subkey-Length",  pSUBKEYLENGTH },
	{ "Subkey-Usage",   pSUBKEYUSAGE },
	{ "Name-Real",      pNAMEREAL },
	{ "Name-Email",     pNAMEEMAIL },
	{ "Name-Comment",   pNAMECOMMENT },
	{ "Expire-Date",    pEXPIREDATE },
	{ "Passphrase",     pPASSPHRASE },
	{ "Preferences",    pPREFERENCES },
	{ "Revoker",        pREVOKER },
	{ NULL, 0 }
    };
    FILE *fp;
    char line[1024], *p;
    int lnr;
    const char *err = NULL;
    struct para_data_s *para, *r;
    int i;
    struct output_control_s outctrl;

    memset( &outctrl, 0, sizeof( outctrl ) );

    if( !fname || !*fname || !strcmp(fname,"-") ) {
	fp = stdin;
	fname = "-";
    }
    else {
	fp = fopen( fname, "r" );
	if( !fp ) {
	    log_error(_("can't open `%s': %s\n"), fname, strerror(errno) );
	    return;
	}
    }

    lnr = 0;
    err = NULL;
    para = NULL;
    while( fgets( line, DIM(line)-1, fp ) ) {
	char *keyword, *value;

	lnr++;
	if( *line && line[strlen(line)-1] != '\n' ) {
	    err = "line too long";
	    break;
	}
	for( p = line; isspace(*(byte*)p); p++ )
	    ;
	if( !*p || *p == '#' )
	    continue;
	keyword = p;
	if( *keyword == '%' ) {
	    for( ; !isspace(*(byte*)p); p++ )
		;
	    if( *p )
		*p++ = 0;
	    for( ; isspace(*(byte*)p); p++ )
		;
	    value = p;
	    trim_trailing_ws( value, strlen(value) );
	    if( !ascii_strcasecmp( keyword, "%echo" ) )
		log_info("%s\n", value );
	    else if( !ascii_strcasecmp( keyword, "%dry-run" ) )
		outctrl.dryrun = 1;
	    else if( !ascii_strcasecmp( keyword, "%commit" ) ) {
		outctrl.lnr = lnr;
		proc_parameter_file( para, fname, &outctrl );
		release_parameter_list( para );
		para = NULL;
	    }
	    else if( !ascii_strcasecmp( keyword, "%pubring" ) ) {
		if( outctrl.pub.fname && !strcmp( outctrl.pub.fname, value ) )
		    ; /* still the same file - ignore it */
		else {
		    m_free( outctrl.pub.newfname );
		    outctrl.pub.newfname = m_strdup( value );
		    outctrl.use_files = 1;
		}
	    }
	    else if( !ascii_strcasecmp( keyword, "%secring" ) ) {
		if( outctrl.sec.fname && !strcmp( outctrl.sec.fname, value ) )
		    ; /* still the same file - ignore it */
		else {
		   m_free( outctrl.sec.newfname );
		   outctrl.sec.newfname = m_strdup( value );
		   outctrl.use_files = 1;
		}
	    }
	    else
		log_info("skipping control `%s' (%s)\n", keyword, value );


	    continue;
	}


	if( !(p = strchr( p, ':' )) || p == keyword ) {
	    err = "missing colon";
	    break;
	}
	if( *p )
	    *p++ = 0;
	for( ; isspace(*(byte*)p); p++ )
	    ;
	if( !*p ) {
	    err = "missing argument";
	    break;
	}
	value = p;
	trim_trailing_ws( value, strlen(value) );

	for(i=0; keywords[i].name; i++ ) {
	    if( !ascii_strcasecmp( keywords[i].name, keyword ) )
		break;
	}
	if( !keywords[i].name ) {
	    err = "unknown keyword";
	    break;
	}
	if( keywords[i].key != pKEYTYPE && !para ) {
	    err = "parameter block does not start with \"Key-Type\"";
	    break;
	}

	if( keywords[i].key == pKEYTYPE && para ) {
	    outctrl.lnr = lnr;
	    proc_parameter_file( para, fname, &outctrl );
	    release_parameter_list( para );
	    para = NULL;
	}
	else {
	    for( r = para; r; r = r->next ) {
		if( r->key == keywords[i].key )
		    break;
	    }
	    if( r ) {
		err = "duplicate keyword";
		break;
	    }
	}
	r = m_alloc_clear( sizeof *r + strlen( value ) );
	r->lnr = lnr;
	r->key = keywords[i].key;
	strcpy( r->u.value, value );
	r->next = para;
	para = r;
    }
    if( err )
	log_error("%s:%d: %s\n", fname, lnr, err );
    else if( ferror(fp) ) {
	log_error("%s:%d: read error: %s\n", fname, lnr, strerror(errno) );
    }
    else if( para ) {
	outctrl.lnr = lnr;
	proc_parameter_file( para, fname, &outctrl );
    }

    if( outctrl.use_files ) { /* close open streams */
	iobuf_close( outctrl.pub.stream );
	iobuf_close( outctrl.sec.stream );
	m_free( outctrl.pub.fname );
	m_free( outctrl.pub.newfname );
	m_free( outctrl.sec.fname );
	m_free( outctrl.sec.newfname );
    }

    release_parameter_list( para );
    if( strcmp( fname, "-" ) )
	fclose(fp);
}


/****************
 * Generate a keypair
 * (fname is only used in batch mode)
 */
void
generate_keypair( const char *fname )
{
    unsigned int nbits;
    char *uid = NULL;
    DEK *dek;
    STRING2KEY *s2k;
    int algo;
    unsigned int use;
    int both = 0;
    u32 expire;
    struct para_data_s *para = NULL;
    struct para_data_s *r;
    struct output_control_s outctrl;

    memset( &outctrl, 0, sizeof( outctrl ) );

    if( opt.batch ) {
	read_parameter_file( fname );
	return;
    }

    algo = ask_algo( 0, &use );
    if( !algo ) { /* default: DSA with ElG subkey of the specified size */
	both = 1;
	r = m_alloc_clear( sizeof *r + 20 );
	r->key = pKEYTYPE;
	sprintf( r->u.value, "%d", PUBKEY_ALGO_DSA );
	r->next = para;
	para = r;
	tty_printf(_("DSA keypair will have 1024 bits.\n"));
	r = m_alloc_clear( sizeof *r + 20 );
	r->key = pKEYLENGTH;
	strcpy( r->u.value, "1024" );
	r->next = para;
	para = r;

	algo = PUBKEY_ALGO_ELGAMAL_E;
	r = m_alloc_clear( sizeof *r + 20 );
	r->key = pSUBKEYTYPE;
	sprintf( r->u.value, "%d", algo );
	r->next = para;
	para = r;
    }
    else {
	r = m_alloc_clear( sizeof *r + 20 );
	r->key = pKEYTYPE;
	sprintf( r->u.value, "%d", algo );
	r->next = para;
	para = r;

        if (use) {
            r = m_alloc_clear( sizeof *r + 20 );
            r->key = pKEYUSAGE;
            sprintf( r->u.value, "%s%s",
                     (use & PUBKEY_USAGE_SIG)? "sign ":"",
                     (use & PUBKEY_USAGE_ENC)? "encrypt ":"" );
            r->next = para;
            para = r;
        }

    }

    nbits = ask_keysize( algo );
    r = m_alloc_clear( sizeof *r + 20 );
    r->key = both? pSUBKEYLENGTH : pKEYLENGTH;
    sprintf( r->u.value, "%u", nbits);
    r->next = para;
    para = r;

    expire = ask_expire_interval(0);
    r = m_alloc_clear( sizeof *r + 20 );
    r->key = pKEYEXPIRE;
    r->u.expire = expire;
    r->next = para;
    para = r;
    r = m_alloc_clear( sizeof *r + 20 );
    r->key = pSUBKEYEXPIRE;
    r->u.expire = expire;
    r->next = para;
    para = r;

    uid = ask_user_id(0);
    if( !uid ) {
	log_error(_("Key generation canceled.\n"));
	release_parameter_list( para );
	return;
    }
    r = m_alloc_clear( sizeof *r + strlen(uid) );
    r->key = pUSERID;
    strcpy( r->u.value, uid );
    r->next = para;
    para = r;

    dek = ask_passphrase( &s2k );
    if( dek ) {
	r = m_alloc_clear( sizeof *r );
	r->key = pPASSPHRASE_DEK;
	r->u.dek = dek;
	r->next = para;
	para = r;
	r = m_alloc_clear( sizeof *r );
	r->key = pPASSPHRASE_S2K;
	r->u.s2k = s2k;
	r->next = para;
	para = r;
    }

    proc_parameter_file( para, "[internal]", &outctrl );
    release_parameter_list( para );
}

static void
print_status_key_created (int letter, PKT_public_key *pk)
{
  byte array[MAX_FINGERPRINT_LEN], *s;
  char buf[MAX_FINGERPRINT_LEN*2+30], *p;
  size_t i, n;
  
  p = buf;
  *p++ = letter;
  *p++ = ' ';
  fingerprint_from_pk (pk, array, &n);
  s = array;
  for (i=0; i < n ; i++, s++, p += 2)
    sprintf (p, "%02X", *s);
  *p = 0;
  write_status_text (STATUS_KEY_CREATED, buf);
}


static void
do_generate_keypair( struct para_data_s *para,
		     struct output_control_s *outctrl )
{
    KBNODE pub_root = NULL;
    KBNODE sec_root = NULL;
    PKT_secret_key *sk = NULL;
    const char *s;
    struct revocation_key *revkey;
    int rc;
    int did_sub = 0;

    if( outctrl->dryrun ) {
	log_info("dry-run mode - key generation skipped\n");
	return;
    }


    if( outctrl->use_files ) {
	if( outctrl->pub.newfname ) {
	    iobuf_close(outctrl->pub.stream);
	    outctrl->pub.stream = NULL;
	    m_free( outctrl->pub.fname );
	    outctrl->pub.fname =  outctrl->pub.newfname;
	    outctrl->pub.newfname = NULL;

	    outctrl->pub.stream = iobuf_create( outctrl->pub.fname );
	    if( !outctrl->pub.stream ) {
		log_error("can't create `%s': %s\n", outctrl->pub.newfname,
						     strerror(errno) );
		return;
	    }
	    if( opt.armor ) {
		outctrl->pub.afx.what = 1;
		iobuf_push_filter( outctrl->pub.stream, armor_filter,
						    &outctrl->pub.afx );
	    }
	}
	if( outctrl->sec.newfname ) {
	    iobuf_close(outctrl->sec.stream);
	    outctrl->sec.stream = NULL;
	    m_free( outctrl->sec.fname );
	    outctrl->sec.fname =  outctrl->sec.newfname;
	    outctrl->sec.newfname = NULL;

	    outctrl->sec.stream = iobuf_create( outctrl->sec.fname );
	    if( !outctrl->sec.stream ) {
		log_error("can't create `%s': %s\n", outctrl->sec.newfname,
						     strerror(errno) );
		return;
	    }
	    if( opt.armor ) {
		outctrl->sec.afx.what = 5;
		iobuf_push_filter( outctrl->sec.stream, armor_filter,
						    &outctrl->sec.afx );
	    }
	}
	assert( outctrl->pub.stream );
	assert( outctrl->sec.stream );
        if( opt.verbose ) {
            log_info(_("writing public key to `%s'\n"), outctrl->pub.fname );
            log_info(_("writing secret key to `%s'\n"), outctrl->sec.fname );
        }
    }


    /* we create the packets as a tree of kbnodes. Because the structure
     * we create is known in advance we simply generate a linked list
     * The first packet is a dummy comment packet which we flag
     * as deleted.  The very first packet must always be a KEY packet.
     */
    pub_root = make_comment_node("#"); delete_kbnode(pub_root);
    sec_root = make_comment_node("#"); delete_kbnode(sec_root);

    rc = do_create( get_parameter_algo( para, pKEYTYPE ),
		    get_parameter_uint( para, pKEYLENGTH ),
		    pub_root, sec_root,
		    get_parameter_dek( para, pPASSPHRASE_DEK ),
		    get_parameter_s2k( para, pPASSPHRASE_S2K ),
		    &sk,
		    get_parameter_u32( para, pKEYEXPIRE ) );

    if(!rc && (revkey=get_parameter_revkey(para,pREVOKER)))
      {
	rc=write_direct_sig(pub_root,pub_root,sk,revkey);
	if(!rc)
	  write_direct_sig(sec_root,pub_root,sk,revkey);
      }

    if( !rc && (s=get_parameter_value(para, pUSERID)) ) {
	write_uid(pub_root, s );
	if( !rc )
	    write_uid(sec_root, s );
	if( !rc )
	    rc = write_selfsig(pub_root, pub_root, sk,
                               get_parameter_uint (para, pKEYUSAGE));
	if( !rc )
	    rc = write_selfsig(sec_root, pub_root, sk,
                               get_parameter_uint (para, pKEYUSAGE));
    }

    if( get_parameter( para, pSUBKEYTYPE ) ) {
	rc = do_create( get_parameter_algo( para, pSUBKEYTYPE ),
			get_parameter_uint( para, pSUBKEYLENGTH ),
			pub_root, sec_root,
			get_parameter_dek( para, pPASSPHRASE_DEK ),
			get_parameter_s2k( para, pPASSPHRASE_S2K ),
			NULL,
			get_parameter_u32( para, pSUBKEYEXPIRE ) );
	if( !rc )
	    rc = write_keybinding(pub_root, pub_root, sk,
               			  get_parameter_uint (para, pSUBKEYUSAGE));
	if( !rc )
	    rc = write_keybinding(sec_root, pub_root, sk,
               			  get_parameter_uint (para, pSUBKEYUSAGE));
        did_sub = 1;
    }


    if( !rc && outctrl->use_files ) { /* direct write to specified files */
	rc = write_keyblock( outctrl->pub.stream, pub_root );
	if( rc )
	    log_error("can't write public key: %s\n", g10_errstr(rc) );
	if( !rc ) {
	    rc = write_keyblock( outctrl->sec.stream, sec_root );
	    if( rc )
		log_error("can't write secret key: %s\n", g10_errstr(rc) );
	}

    }
    else if( !rc ) { /* write to the standard keyrings */
	KEYDB_HANDLE pub_hd = keydb_new (0);
	KEYDB_HANDLE sec_hd = keydb_new (1);

        /* FIXME: we may have to create the keyring first */
        rc = keydb_locate_writable (pub_hd, NULL);
        if (rc) 
    	    log_error (_("no writable public keyring found: %s\n"),
                       g10_errstr (rc));

        if (!rc) {  
            rc = keydb_locate_writable (sec_hd, NULL);
            if (rc) 
                log_error (_("no writable secret keyring found: %s\n"),
                           g10_errstr (rc));
        }

        if (!rc && opt.verbose) {
            log_info(_("writing public key to `%s'\n"),
                     keydb_get_resource_name (pub_hd));
            log_info(_("writing secret key to `%s'\n"),
                     keydb_get_resource_name (sec_hd));
        }

        if (!rc) {
	    rc = keydb_insert_keyblock (pub_hd, pub_root);
            if (rc)
                log_error (_("error writing public keyring `%s': %s\n"),
                           keydb_get_resource_name (pub_hd), g10_errstr(rc));
        }

        if (!rc) {
	    rc = keydb_insert_keyblock (sec_hd, sec_root);
            if (rc)
                log_error (_("error writing secret keyring `%s': %s\n"),
                           keydb_get_resource_name (pub_hd), g10_errstr(rc));
        }

        keydb_release (pub_hd);
        keydb_release (sec_hd);

	if (!rc) {
            int no_enc_rsa =
                get_parameter_algo(para, pKEYTYPE) == PUBKEY_ALGO_RSA
                && get_parameter_uint( para, pKEYUSAGE )
                && !(get_parameter_uint( para,pKEYUSAGE) & PUBKEY_USAGE_ENC);
            PKT_public_key *pk = find_kbnode (pub_root, 
                                    PKT_PUBLIC_KEY)->pkt->pkt.public_key;
            
            update_ownertrust (pk,
                               ((get_ownertrust (pk) & ~TRUST_MASK)
                                | TRUST_ULTIMATE ));

	    if (!opt.batch) {
                tty_printf(_("public and secret key created and signed.\n") );
                tty_printf(_("key marked as ultimately trusted.\n") );
		tty_printf("\n");
		list_keyblock(pub_root,0,1,NULL);
            }
            

	    if( !opt.batch
		&& ( get_parameter_algo( para, pKEYTYPE ) == PUBKEY_ALGO_DSA
                     || no_enc_rsa )
		&& !get_parameter( para, pSUBKEYTYPE ) )
	    {
		tty_printf(_("Note that this key cannot be used for "
			     "encryption.  You may want to use\n"
			     "the command \"--edit-key\" to generate a "
			     "secondary key for this purpose.\n") );
	    }
	}
    }

    if( rc ) {
	if( opt.batch )
	    log_error("key generation failed: %s\n", g10_errstr(rc) );
	else
	    tty_printf(_("Key generation failed: %s\n"), g10_errstr(rc) );
    }
    else {
        PKT_public_key *pk = find_kbnode (pub_root, 
                                    PKT_PUBLIC_KEY)->pkt->pkt.public_key;
        print_status_key_created (did_sub? 'B':'P', pk);
    }
    release_kbnode( pub_root );
    release_kbnode( sec_root );
    if( sk ) /* the unprotected  secret key */
	free_secret_key(sk);
}


/****************
 * add a new subkey to an existing key.
 * Returns true if a new key has been generated and put into the keyblocks.
 */
int
generate_subkeypair( KBNODE pub_keyblock, KBNODE sec_keyblock )
{
    int okay=0, rc=0;
    KBNODE node;
    PKT_secret_key *sk = NULL; /* this is the primary sk */
    int algo;
    unsigned int use;
    u32 expire;
    unsigned nbits;
    char *passphrase = NULL;
    DEK *dek = NULL;
    STRING2KEY *s2k = NULL;
    u32 cur_time;

    /* break out the primary secret key */
    node = find_kbnode( sec_keyblock, PKT_SECRET_KEY );
    if( !node ) {
	log_error("Oops; secret key not found anymore!\n");
	goto leave;
    }

    /* make a copy of the sk to keep the protected one in the keyblock */
    sk = copy_secret_key( NULL, node->pkt->pkt.secret_key );

    cur_time = make_timestamp();
    if( sk->timestamp > cur_time ) {
	ulong d = sk->timestamp - cur_time;
	log_info( d==1 ? _("key has been created %lu second "
			   "in future (time warp or clock problem)\n")
		       : _("key has been created %lu seconds "
			   "in future (time warp or clock problem)\n"), d );
	if( !opt.ignore_time_conflict ) {
	    rc = G10ERR_TIME_CONFLICT;
	    goto leave;
	}
    }

    if (sk->version < 4) {
        log_info (_("NOTE: creating subkeys for v3 keys "
                    "is not OpenPGP compliant\n"));
	goto leave;
    }

    /* unprotect to get the passphrase */
    switch( is_secret_key_protected( sk ) ) {
      case -1:
	rc = G10ERR_PUBKEY_ALGO;
	break;
      case 0:
	tty_printf("This key is not protected.\n");
	break;
      default:
	tty_printf("Key is protected.\n");
	rc = check_secret_key( sk, 0 );
	if( !rc )
	    passphrase = get_last_passphrase();
	break;
    }
    if( rc )
	goto leave;


    algo = ask_algo( 1, &use );
    assert(algo);
    nbits = ask_keysize( algo );
    expire = ask_expire_interval(0);
    if( !cpr_enabled() && !cpr_get_answer_is_yes("keygen.sub.okay",
						  _("Really create? ") ) )
	goto leave;

    if( passphrase ) {
	s2k = m_alloc_secure( sizeof *s2k );
	s2k->mode = opt.s2k_mode;
	s2k->hash_algo = opt.s2k_digest_algo;
	set_next_passphrase( passphrase );
	dek = passphrase_to_dek( NULL, 0, opt.s2k_cipher_algo, s2k, 2, NULL );
    }

    rc = do_create( algo, nbits, pub_keyblock, sec_keyblock,
				      dek, s2k, NULL, expire );
    if( !rc )
	rc = write_keybinding(pub_keyblock, pub_keyblock, sk, use);
    if( !rc )
	rc = write_keybinding(sec_keyblock, pub_keyblock, sk, use);
    if( !rc ) {
        PKT_public_key *subpk = NULL;

        for (node=pub_keyblock; node; node = node->next ) {
          if (node->pkt->pkttype == PKT_PUBLIC_SUBKEY)
	    subpk = node->pkt->pkt.public_key;
        }
        if (!subpk)
          BUG();
        print_status_key_created ('S', subpk);
	okay = 1;
    }

  leave:
    if( rc )
	log_error(_("Key generation failed: %s\n"), g10_errstr(rc) );
    m_free( passphrase );
    m_free( dek );
    m_free( s2k );
    if( sk ) /* release the copy of the (now unprotected) secret key */
	free_secret_key(sk);
    set_next_passphrase( NULL );
    return okay;
}

/****************
 * Write a keyblock to an output stream
 */
static int
write_keyblock( IOBUF out, KBNODE node )
{
    for( ; node ; node = node->next ) {
	int rc = build_packet( out, node->pkt );
	if( rc ) {
	    log_error("build_packet(%d) failed: %s\n",
			node->pkt->pkttype, g10_errstr(rc) );
	    return G10ERR_WRITE_FILE;
	}
    }
    return 0;
}