bin/dnssec/dnssec-signzone.c

	dnssec-signzone.c revision b8dd48ecf83142f6ee7238cbd68fec455e527fc8
/*
 * Copyright (C) 1999, 2000  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <isc/types.h>
#include <isc/assertions.h>
#include <isc/commandline.h>
#include <isc/boolean.h>
#include <isc/buffer.h>
#include <isc/error.h>
#include <isc/mem.h>
#include <isc/stdtime.h>
#include <isc/list.h>
#include <isc/util.h>

#include <dns/types.h>
#include <dns/name.h>
#include <dns/fixedname.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/rdata.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/dnssec.h>
#include <dns/keyvalues.h>
#include <dns/secalg.h>
#include <dns/nxt.h>
#include <dns/time.h>
#include <dns/zone.h>
#include <dns/log.h>

#include <dst/dst.h>

#define BUFSIZE 2048
#define is_zone_key(key) ((dst_key_flags(key) & DNS_KEYFLAG_OWNERMASK) \
              == DNS_KEYOWNER_ZONE)

typedef struct signer_key_struct signer_key_t;
typedef struct signer_array_struct signer_array_t;

struct signer_key_struct {
    dst_key_t *key;
    isc_boolean_t isdefault;
    ISC_LINK(signer_key_t) link;
};

struct signer_array_struct {
    unsigned char array[BUFSIZE];
    ISC_LINK(signer_array_t) link;
};

static ISC_LIST(signer_key_t) keylist;
static isc_stdtime_t starttime = 0, endtime = 0, now;
static int cycle = -1;
static int verbose;
static int tryverify = 0;

static isc_mem_t *mctx = NULL;

static inline void
fatal(char *message) {
    fprintf(stderr, "%s\n", message);
    exit(1);
}

static inline void
check_result(isc_result_t result, char *message) {
    if (result != ISC_R_SUCCESS) {
        fprintf(stderr, "%s: %s\n", message,
            isc_result_totext(result));
        exit(1);
    }
}

static void
vbprintf(int level, const char *fmt, ...) {
    va_list ap;
    if (level > verbose)
        return;
    va_start(ap, fmt);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
}

/* Not thread-safe! */
static char *
nametostr(dns_name_t *name) {
    isc_buffer_t b;
    isc_region_t r;
    static char data[1025];

    isc_buffer_init(&b, data, sizeof(data));
    dns_name_totext(name, ISC_FALSE, &b);
    isc_buffer_usedregion(&b, &r);
    r.base[r.length] = 0;
    return (char *) r.base;
}

/* Not thread-safe! */
static char *
typetostr(const dns_rdatatype_t type) {
    isc_buffer_t b;
    isc_region_t r;
    static char data[10];

    isc_buffer_init(&b, data, sizeof(data));
    dns_rdatatype_totext(type, &b);
    isc_buffer_usedregion(&b, &r);
    r.base[r.length] = 0;
    return (char *) r.base;
}

/* Not thread-safe! */
static char *
algtostr(const dns_secalg_t alg) {
    isc_buffer_t b;
    isc_region_t r;
    static char data[10];

    isc_buffer_init(&b, data, sizeof(data));
    dns_secalg_totext(alg, &b);
    isc_buffer_usedregion(&b, &r);
    r.base[r.length] = 0;
    return (char *) r.base;
}

static inline void
set_bit(unsigned char *array, unsigned int index, unsigned int bit) {
    unsigned int byte, shift, mask;

    byte = array[index / 8];
    shift = 7 - (index % 8);
    mask = 1 << shift;

    if (bit)
        array[index / 8] |= mask;
    else
        array[index / 8] &= (~mask & 0xFF);
}

static void
signwithkey(dns_name_t *name, dns_rdataset_t *rdataset, dns_rdata_t *rdata,
        dst_key_t *key, isc_buffer_t *b)
{
    isc_result_t result;

    dns_rdata_init(rdata);
    result = dns_dnssec_sign(name, rdataset, key, &starttime, &endtime,
                 mctx, b, rdata);
    check_result(result, "dns_dnssec_sign()");

    if (tryverify != 0) {
        result = dns_dnssec_verify(name, rdataset, key,
                       ISC_TRUE, mctx, rdata);
            if (result == ISC_R_SUCCESS)
                vbprintf(3, "\tsignature verified\n");
            else
                vbprintf(3, "\tsignature failed to verify\n");
    }
}

static inline isc_boolean_t
issigningkey(signer_key_t *key) {
    return (key->isdefault);
}

static inline isc_boolean_t
iszonekey(signer_key_t *key, dns_db_t *db) {
    char origin[1024];
    isc_buffer_t b;
    isc_result_t result;

    isc_buffer_init(&b, origin, sizeof(origin));
    result = dns_name_totext(dns_db_origin(db), ISC_FALSE, &b);
    check_result(result, "dns_name_totext()");

    return (ISC_TF(strcasecmp(dst_key_name(key->key), origin) == 0 &&
        (dst_key_flags(key->key) & DNS_KEYFLAG_OWNERMASK) ==
         DNS_KEYOWNER_ZONE));
}

/*
 * Finds the key that generated a SIG, if possible.  First look at the keys
 * that we've loaded already, and then see if there's a key on disk.
 */
static signer_key_t *
keythatsigned(dns_rdata_sig_t *sig) {
    char *keyname;
    isc_result_t result;
    dst_key_t *pubkey = NULL, *privkey = NULL;
    signer_key_t *key;

    keyname = nametostr(&sig->signer);

    key = ISC_LIST_HEAD(keylist);
    while (key != NULL) {
        if (sig->keyid == dst_key_id(key->key) &&
            sig->algorithm == dst_key_alg(key->key) &&
            strcasecmp(keyname, dst_key_name(key->key)) == 0)
            return key;
        key = ISC_LIST_NEXT(key, link);
    }

    result = dst_key_fromfile(keyname, sig->keyid, sig->algorithm,
                  DST_TYPE_PUBLIC, mctx, &pubkey);
    if (result != ISC_R_SUCCESS)
        return (NULL);

    key = isc_mem_get(mctx, sizeof(signer_key_t));
    if (key == NULL)
        check_result(ISC_R_FAILURE, "isc_mem_get");

    result = dst_key_fromfile(keyname, sig->keyid, sig->algorithm,
                  DST_TYPE_PRIVATE, mctx, &privkey);
    if (result == ISC_R_SUCCESS) {
        key->key = privkey;
        dst_key_free(pubkey);
    }
    else
        key->key = pubkey;
    key->isdefault = ISC_FALSE;
    ISC_LIST_APPEND(keylist, key, link);
    return key;
}

/*
 * Check to see if we expect to find a key at this name.  If we see a SIG
 * and can't find the signing key that we expect to find, we drop the sig.
 * I'm not sure if this is completely correct, but it seems to work.
 */
static isc_boolean_t
expecttofindkey(dns_name_t *name, dns_db_t *db, dns_dbversion_t *version) {
    unsigned int options = DNS_DBFIND_NOWILD;
    dns_fixedname_t fname;
    isc_result_t result;

    dns_fixedname_init(&fname);
    result = dns_db_find(db, name, version, dns_rdatatype_key, options,
                 0, NULL, dns_fixedname_name(&fname), NULL, NULL);
    switch (result) {
        case ISC_R_SUCCESS:
        case DNS_R_NXDOMAIN:
        case DNS_R_NXRRSET:
            return ISC_TRUE;
        case DNS_R_DELEGATION:
        case DNS_R_CNAME:
        case DNS_R_DNAME:
            return ISC_FALSE;
        default:
            check_result(result, "dns_db_find");
            return ISC_FALSE; /* removes a warning */
    }
}

static inline isc_boolean_t
setverifies(dns_name_t *name, dns_rdataset_t *set, signer_key_t *key,
        dns_rdata_t *sig)
{
    isc_result_t result;
    result = dns_dnssec_verify(name, set, key->key, ISC_FALSE, mctx, sig);
    return (ISC_TF(result == ISC_R_SUCCESS));
}

#define allocbufferandrdata \
    isc_buffer_t b; \
    trdata = isc_mem_get(mctx, sizeof(dns_rdata_t)); \
    tdata = isc_mem_get(mctx, sizeof(signer_array_t)); \
    ISC_LIST_APPEND(arraylist, tdata, link); \
    if (trdata == NULL || tdata == NULL) \
        check_result(ISC_R_FAILURE, "isc_mem_get"); \
    isc_buffer_init(&b, tdata->array, sizeof(tdata->array));

/*
 * Signs a set.  Goes through contortions to decide if each SIG should
 * be dropped or retained, and then determines if any new SIGs need to
 * be generated.
 */
static void
signset(dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node,
     dns_name_t *name, dns_rdataset_t *set)
{
    dns_rdatalist_t siglist;
    dns_rdataset_t sigset, oldsigset;
    dns_rdata_t oldsigrdata;
    dns_rdata_t *trdata;
    dns_rdata_sig_t sig;
    signer_key_t *key;
    isc_result_t result;
    isc_boolean_t notsigned = ISC_TRUE, nosigs = ISC_FALSE;
    isc_boolean_t wassignedby[256], nowsignedby[256];
    signer_array_t *tdata;
    ISC_LIST(signer_array_t) arraylist;
    int i;

    ISC_LIST_INIT(siglist.rdata);
    ISC_LIST_INIT(arraylist);

    for (i = 0; i < 256; i++)
        wassignedby[i] = nowsignedby[i] = ISC_FALSE;

    dns_rdataset_init(&oldsigset);
    result = dns_db_findrdataset(db, node, version, dns_rdatatype_sig,
                     set->type, 0, &oldsigset, NULL);
    if (result == ISC_R_NOTFOUND) {
        result = ISC_R_SUCCESS;
        nosigs = ISC_TRUE;
    }
    check_result(result, "dns_db_findrdataset()");

    vbprintf(1, "%s/%s:\n", nametostr(name), typetostr(set->type));

    if (!nosigs) {
        result = dns_rdataset_first(&oldsigset);
        while (result == ISC_R_SUCCESS) {
            isc_boolean_t expired, future;
            isc_boolean_t keep = ISC_FALSE, resign = ISC_FALSE;

            dns_rdataset_current(&oldsigset, &oldsigrdata);

            result = dns_rdata_tostruct(&oldsigrdata, &sig, mctx);
            check_result(result, "dns_rdata_tostruct");

            expired = ISC_TF(now + cycle > sig.timeexpire);
            future = ISC_TF(now < sig.timesigned);

            key = keythatsigned(&sig);

            if (sig.timesigned > sig.timeexpire) {
                /* sig is dropped and not replaced */
                vbprintf(2, "\tsig by %s/%s/%d dropped - "
                     "invalid validity period\n",
                     nametostr(&sig.signer),
                     algtostr(sig.algorithm),
                     sig.keyid);
            }
            else if (key == NULL && !future &&
                 expecttofindkey(&sig.signer, db, version))
            {
                /* sig is dropped and not replaced */
                vbprintf(2, "\tsig by %s/%s/%d dropped - "
                     "private key not found\n",
                     nametostr(&sig.signer),
                     algtostr(sig.algorithm),
                     sig.keyid);
            }
            else if (key == NULL || future) {
                vbprintf(2, "\tsig by %s/%s/%d %s - "
                     "key not found\n",
                     expired ? "retained" : "dropped",
                     nametostr(&sig.signer),
                     algtostr(sig.algorithm),
                     sig.keyid);
                if (!expired)
                    keep = ISC_TRUE;
            }
            else if (issigningkey(key)) {
                if (!expired &&
                    setverifies(name, set, key, &oldsigrdata))
                {
                    vbprintf(2,
                         "\tsig by %s/%s/%d retained\n",
                         nametostr(&sig.signer),
                         algtostr(sig.algorithm),
                         sig.keyid);
                    keep = ISC_TRUE;
                    wassignedby[sig.algorithm] = ISC_TRUE;
                }
                else {
                    vbprintf(2,
                         "\tsig by %s/%s/%d dropped - "
                         "%s\n",
                         nametostr(&sig.signer),
                         algtostr(sig.algorithm),
                         sig.keyid,
                         expired ? "expired" :
                               "failed to verify");
                    wassignedby[sig.algorithm] = ISC_TRUE;
                    resign = ISC_TRUE;
                }
            }
            else if (iszonekey(key, db)) {
                if (!expired &&
                    setverifies(name, set, key, &oldsigrdata))
                {
                    vbprintf(2,
                         "\tsig by %s/%s/%d retained\n",
                         nametostr(&sig.signer),
                         algtostr(sig.algorithm),
                         sig.keyid);
                    keep = ISC_TRUE;
                    wassignedby[sig.algorithm] = ISC_TRUE;
                    nowsignedby[sig.algorithm] = ISC_TRUE;
                }
                else {
                    vbprintf(2,
                         "\tsig by %s/%s/%d dropped - ",
                         "%s\n",
                         nametostr(&sig.signer),
                         algtostr(sig.algorithm),
                         sig.keyid,
                         expired ? "expired" :
                               "failed to verify");
                    wassignedby[sig.algorithm] = ISC_TRUE;
                    if (dst_key_isprivate(key->key))
                        resign = ISC_TRUE;
                }
            }
            else if (!expired) {
                vbprintf(2, "\tsig by %s/%s/%d retained\n",
                     nametostr(&sig.signer),
                     algtostr(sig.algorithm),
                     sig.keyid);
                keep = ISC_TRUE;
            }
            else {
                vbprintf(2, "\tsig by %s/%s/%d expired\n",
                     nametostr(&sig.signer),
                     algtostr(sig.algorithm),
                     sig.keyid);
            }

            if (keep) {
                allocbufferandrdata;
                result = dns_rdata_fromstruct(trdata,
                                  set->rdclass,
                                  dns_rdatatype_sig,
                                  &sig, &b);
                nowsignedby[sig.algorithm] = ISC_TRUE;
                ISC_LIST_APPEND(siglist.rdata, trdata, link);
            }
            else if (resign) {
                allocbufferandrdata;
                vbprintf(1, "\tresigning with key %s/%s/%d\n",
                       dst_key_name(key->key),
                       algtostr(dst_key_alg(key->key)),
                       dst_key_id(key->key));
                signwithkey(name, set, trdata, key->key, &b);
                nowsignedby[sig.algorithm] = ISC_TRUE;
                ISC_LIST_APPEND(siglist.rdata, trdata, link);
            }

            dns_rdata_freestruct(&sig);
            result = dns_rdataset_next(&oldsigset);
        }
        if (result == ISC_R_NOMORE)
            result = ISC_R_SUCCESS;
        check_result(result, "dns_db_dns_rdataset_first()/next()");
        dns_rdataset_disassociate(&oldsigset);
    }

    for (i = 0; i < 256; i++)
        if (wassignedby[i] != 0) {
            notsigned = ISC_FALSE;
            break;
        }

    key = ISC_LIST_HEAD(keylist);
    while (key != NULL) {
        int alg = dst_key_alg(key->key);
        if (key->isdefault &&
            (notsigned || (wassignedby[alg] && !nowsignedby[alg])))
        {
            allocbufferandrdata;
            vbprintf(1, "\tsigning with key %s/%s/%d\n",
                   dst_key_name(key->key),
                   algtostr(dst_key_alg(key->key)),
                   dst_key_id(key->key));
            signwithkey(name, set, trdata, key->key, &b);
            ISC_LIST_APPEND(siglist.rdata, trdata, link);
        }
        key = ISC_LIST_NEXT(key, link);
    }

    if (!ISC_LIST_EMPTY(siglist.rdata)) {
        siglist.rdclass = set->rdclass;
        siglist.type = dns_rdatatype_sig;
        siglist.covers = set->type;
        if (endtime - starttime < set->ttl)
            siglist.ttl = endtime - starttime;
        else
            siglist.ttl = set->ttl;
        dns_rdataset_init(&sigset);
        result = dns_rdatalist_tordataset(&siglist, &sigset);
        check_result(result, "dns_rdatalist_tordataset");
        result = dns_db_addrdataset(db, node, version, 0, &sigset,
                        0, NULL);
        if (result == DNS_R_UNCHANGED)
            result = ISC_R_SUCCESS;
        check_result(result, "dns_db_addrdataset");
        dns_rdataset_disassociate(&sigset);
    }
    else if (!nosigs) {
#if 0
        /*
         * If this is compiled in, running a signed set through the
         * signer with no private keys causes DNS_R_BADDB to occur
         * later.  This is bad.
         */
        result = dns_db_deleterdataset(db, node, version,
                           dns_rdatatype_sig, set->type);
        if (result == ISC_R_NOTFOUND)
            result = ISC_R_SUCCESS;
        check_result(result, "dns_db_deleterdataset");
#endif
    }

    trdata = ISC_LIST_HEAD(siglist.rdata);
    while (trdata != NULL) {
        dns_rdata_t *next = ISC_LIST_NEXT(trdata, link);
        isc_mem_put(mctx, trdata, sizeof(dns_rdata_t));
        trdata = next;
    }

    tdata = ISC_LIST_HEAD(arraylist);
    while (tdata != NULL) {
        signer_array_t *next = ISC_LIST_NEXT(tdata, link);
        isc_mem_put(mctx, tdata, sizeof(signer_array_t));
        tdata = next;
    }
}

/* Determine if a KEY set contains a null key */
static isc_boolean_t
hasnullkey(dns_rdataset_t rdataset) {
    isc_result_t result;
    dns_rdata_t rdata;
    isc_uint32_t flags;

    result = dns_rdataset_first(&rdataset);
    while (result == ISC_R_SUCCESS) {
        dst_key_t *key = NULL;

        dns_rdataset_current(&rdataset, &rdata);
        result = dns_dnssec_keyfromrdata(dns_rootname,
                         &rdata, mctx, &key);
        check_result(result, "dns_dnssec_keyfromrdata()");
        flags = dst_key_flags(key);
        dst_key_free(key);
        if (((flags & DNS_KEYFLAG_TYPEMASK) == DNS_KEYTYPE_NOKEY) &&
            ((flags & DNS_KEYFLAG_OWNERMASK) == DNS_KEYOWNER_ZONE))
            return (ISC_TRUE);
        result = dns_rdataset_next(&rdataset);
    }
    if (result != ISC_R_NOMORE)
        check_result(result, "iteration over keys");
    return (ISC_FALSE);
}

/*
 * Signs all records at a name.  This mostly just signs each set individually,
 * but also handles exceptional cases and adds the SIG bit to any NXTs
 * generated earlier.
 */
static void
signname(dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node,
     dns_name_t *name, isc_boolean_t atorigin)
{
    isc_result_t result;
    dns_rdata_t rdata;
    dns_rdataset_t rdataset, nsset;
    dns_rdatasetiter_t *rdsiter;
    isc_boolean_t isdelegation = ISC_FALSE;
    static int warnwild = 0;

    if (dns_name_iswildcard(name)) {
        fprintf(stderr, "Warning: wildcard name seen: %s\n",
            nametostr(name));
        if (warnwild++ == 0)
            fprintf(stderr, "\tBIND 9 doesn't completely handle "
                "wildcards in secure zones\n");
    }
    if (!atorigin) {
        dns_rdataset_init(&nsset);
        result = dns_db_findrdataset(db, node, version,
                         dns_rdatatype_ns, 0, 0, &nsset,
                         NULL);
        /* Is this a delegation point? */
        if (result == ISC_R_SUCCESS) {
            isdelegation = ISC_TRUE;
            dns_rdataset_disassociate(&nsset);
        }
    }
    dns_rdataset_init(&rdataset);
    rdsiter = NULL;
    result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
    check_result(result, "dns_db_allrdatasets()");
    result = dns_rdatasetiter_first(rdsiter);
    while (result == ISC_R_SUCCESS) {
        dns_rdatasetiter_current(rdsiter, &rdataset);

        /* If this is a SIG set, skip it. */
        if (rdataset.type == dns_rdatatype_sig)
            goto skip;

        /* If this is a KEY set at the apex, skip it. */
        if (rdataset.type == dns_rdatatype_key && atorigin)
            goto skip;

        /*
         * If this name is a delegation point, skip all records
         * except a KEY set containing a NULL key or an NXT set.
         */
        if (isdelegation) {
            switch (rdataset.type) {
                case dns_rdatatype_nxt:
                    break;
                case dns_rdatatype_key:
                    if (hasnullkey(rdataset))
                        break;
                    goto skip;
                default:
                    goto skip;
            }
        }

        /*
         * There probably should be a dns_nxtsetbit, but it can get
         * complicated if we need to extend the length of the
         * bit set.  In this case, since the NXT bit is set and
         * SIG < NXT, the easy way works.
         */
        if (rdataset.type == dns_rdatatype_nxt) {
            unsigned char *nxt_bits;
            dns_name_t nxtname;
            isc_region_t r, r2;

            result = dns_rdataset_first(&rdataset);
            check_result(result, "dns_rdataset_first()");
            dns_rdataset_current(&rdataset, &rdata);
            dns_rdata_toregion(&rdata, &r);
            dns_name_init(&nxtname, NULL);
            dns_name_fromregion(&nxtname, &r);
            dns_name_toregion(&nxtname, &r2);
            nxt_bits = r.base + r2.length;
            set_bit(nxt_bits, dns_rdatatype_sig, 1);
        }

        signset(db, version, node, name, &rdataset);

 skip:
        dns_rdataset_disassociate(&rdataset);
        result = dns_rdatasetiter_next(rdsiter);
    }
    if (result != ISC_R_NOMORE)
        fatal("rdataset iteration failed");
    dns_rdatasetiter_destroy(&rdsiter);
}

static inline isc_boolean_t
active_node(dns_db_t *db, dns_dbversion_t *version, dns_dbnode_t *node) {
    dns_rdatasetiter_t *rdsiter;
    isc_boolean_t active = ISC_FALSE;
    isc_result_t result;
    dns_rdataset_t rdataset;

    dns_rdataset_init(&rdataset);
    rdsiter = NULL;
    result = dns_db_allrdatasets(db, node, version, 0, &rdsiter);
    check_result(result, "dns_db_allrdatasets()");
    result = dns_rdatasetiter_first(rdsiter);
    while (result == ISC_R_SUCCESS) {
        dns_rdatasetiter_current(rdsiter, &rdataset);
        if (rdataset.type != dns_rdatatype_nxt)
            active = ISC_TRUE;
        dns_rdataset_disassociate(&rdataset);
        if (!active)
            result = dns_rdatasetiter_next(rdsiter);
        else
            result = ISC_R_NOMORE;
    }
    if (result != ISC_R_NOMORE)
        fatal("rdataset iteration failed");
    dns_rdatasetiter_destroy(&rdsiter);

    if (!active) {
        /*
         * Make sure there is no NXT record for this node.
         */
        result = dns_db_deleterdataset(db, node, version,
                           dns_rdatatype_nxt, 0);
        if (result == DNS_R_UNCHANGED)
            result = ISC_R_SUCCESS;
        check_result(result, "dns_db_deleterdataset");
    }

    return (active);
}

static inline isc_result_t
next_active(dns_db_t *db, dns_dbversion_t *version, dns_dbiterator_t *dbiter,
        dns_name_t *name, dns_dbnode_t **nodep)
{
    isc_result_t result;
    isc_boolean_t active;

    do {
        active = ISC_FALSE;
        result = dns_dbiterator_current(dbiter, nodep, name);
        if (result == ISC_R_SUCCESS) {
            active = active_node(db, version, *nodep);
            if (!active) {
                dns_db_detachnode(db, nodep);
                result = dns_dbiterator_next(dbiter);
            }
        }
    } while (result == ISC_R_SUCCESS && !active);

    return (result);
}

static inline isc_result_t
next_nonglue(dns_db_t *db, dns_dbversion_t *version, dns_dbiterator_t *dbiter,
        dns_name_t *name, dns_dbnode_t **nodep, dns_name_t *origin,
        dns_name_t *lastcut)
{
    isc_result_t result;

    do {
        result = next_active(db, version, dbiter, name, nodep);
        if (result == ISC_R_SUCCESS) {
            if (dns_name_issubdomain(name, origin) &&
                (lastcut == NULL ||
                 !dns_name_issubdomain(name, lastcut)))
                return (ISC_R_SUCCESS);
            dns_db_detachnode(db, nodep);
            result = dns_dbiterator_next(dbiter);
        }
    } while (result == ISC_R_SUCCESS);
    return (result);
}

/*
 * Generates NXTs and SIGs for each non-glue name in the zone.
 */
static void
signzone(dns_db_t *db, dns_dbversion_t *version) {
    isc_result_t result, nxtresult;
    dns_dbnode_t *node, *nextnode, *curnode;
    dns_fixedname_t fname, fnextname, fcurname;
    dns_name_t *name, *nextname, *target, *curname, *lastcut;
    dns_dbiterator_t *dbiter;
    isc_boolean_t atorigin = ISC_TRUE;
    dns_name_t *origin;
    dns_rdataset_t soaset;
    dns_rdata_t soarr;
    dns_rdata_soa_t soa;
    dns_ttl_t zonettl;

    dns_fixedname_init(&fname);
    name = dns_fixedname_name(&fname);
    dns_fixedname_init(&fnextname);
    nextname = dns_fixedname_name(&fnextname);
    dns_fixedname_init(&fcurname);
    curname = dns_fixedname_name(&fcurname);

    origin = dns_db_origin(db);

    dns_rdataset_init(&soaset);
    result = dns_db_find(db, origin, version, dns_rdatatype_soa,
                 0, 0, NULL, name, &soaset, NULL);
    check_result(result, "dns_db_find");
    result = dns_rdataset_first(&soaset);
    check_result(result, "dns_rdataset_first");
    dns_rdataset_current(&soaset, &soarr);
    result = dns_rdata_tostruct(&soarr, &soa, mctx);
    check_result(result, "dns_rdataset_tostruct");
    zonettl = soa.minimum;
    dns_rdata_freestruct(&soa);
    dns_rdataset_disassociate(&soaset);

    lastcut = NULL;
    dbiter = NULL;
    result = dns_db_createiterator(db, ISC_FALSE, &dbiter);
    check_result(result, "dns_db_createiterator()");
    result = dns_dbiterator_first(dbiter);
    node = NULL;
    dns_name_clone(origin, name);
    result = next_nonglue(db, version, dbiter, name, &node, origin,
                  lastcut);
    while (result == ISC_R_SUCCESS) {
        nextnode = NULL;
        curnode = NULL;
        dns_dbiterator_current(dbiter, &curnode, curname);
        if (!atorigin) {
            dns_rdatasetiter_t *rdsiter = NULL;
            dns_rdataset_t set;

            dns_rdataset_init(&set);
            result = dns_db_allrdatasets(db, curnode, version,
                             0, &rdsiter);
            check_result(result, "dns_db_allrdatasets");
            result = dns_rdatasetiter_first(rdsiter);
            while (result == ISC_R_SUCCESS) {
                dns_rdatasetiter_current(rdsiter, &set);
                if (set.type == dns_rdatatype_ns) {
                    dns_rdataset_disassociate(&set);
                    break;
                }
                dns_rdataset_disassociate(&set);
                result = dns_rdatasetiter_next(rdsiter);
            }
            if (result != ISC_R_SUCCESS && result != ISC_R_NOMORE)
                fatal("rdataset iteration failed");
            if (result == ISC_R_SUCCESS) {
                if (lastcut != NULL)
                    dns_name_free(lastcut, mctx);
                else {
                    lastcut = isc_mem_get(mctx,
                            sizeof(dns_name_t));
                    if (lastcut == NULL)
                        fatal("allocation failure");
                }
                dns_name_init(lastcut, NULL);
                result = dns_name_dup(curname, mctx, lastcut);
                check_result(result, "dns_name_dup");
            }
            dns_rdatasetiter_destroy(&rdsiter);
        }
        result = dns_dbiterator_next(dbiter);
        if (result == ISC_R_SUCCESS)
            result = next_nonglue(db, version, dbiter, nextname,
                          &nextnode, origin, lastcut);
        if (result == ISC_R_SUCCESS)
            target = nextname;
        else if (result == ISC_R_NOMORE)
            target = origin;
        else {
            target = NULL;  /* Make compiler happy. */
            fatal("db iteration failed");
        }
        nxtresult = dns_buildnxt(db, version, node, target, zonettl);
        check_result(nxtresult, "dns_buildnxt()");
        signname(db, version, node, curname, atorigin);
        atorigin = ISC_FALSE;
        dns_db_detachnode(db, &node);
        dns_db_detachnode(db, &curnode);
        node = nextnode;
    }
    if (result != ISC_R_NOMORE)
        fatal("db iteration failed");
    if (lastcut != NULL) {
        dns_name_free(lastcut, mctx);
        isc_mem_put(mctx, lastcut, sizeof(dns_name_t));
    }
    dns_dbiterator_destroy(&dbiter);
}

static void
loadzone(char *file, char *origin, dns_zone_t **zone) {
    isc_buffer_t b, b2;
    unsigned char namedata[1024];
    int len;
    dns_name_t name;
    isc_result_t result;

    len = strlen(origin);
    isc_buffer_init(&b, origin, len);
    isc_buffer_add(&b, len);

    isc_buffer_init(&b2, namedata, sizeof(namedata));

    dns_name_init(&name, NULL);
    result = dns_name_fromtext(&name, &b, dns_rootname, ISC_FALSE, &b2);
    check_result(result, "dns_name_fromtext()");

    result = dns_zone_create(zone, mctx);
    check_result(result, "dns_zone_create()");

    dns_zone_settype(*zone, dns_zone_master);

    result = dns_zone_setdbtype(*zone, "rbt");
    check_result(result, "dns_zone_setdbtype()");

    result = dns_zone_setdatabase(*zone, file);
    check_result(result, "dns_zone_setdatabase()");

    result = dns_zone_setorigin(*zone, &name);
    check_result(result, "dns_zone_origin()");

    dns_zone_setclass(*zone, dns_rdataclass_in); /* XXX */

    result = dns_zone_load(*zone);
    check_result(result, "dns_zone_load()");
}

static void
getdb(dns_zone_t *zone, dns_db_t **db, dns_dbversion_t **version) {
    isc_result_t result;

    *db = NULL;
    result = dns_zone_getdb(zone, db);
    check_result(result, "dns_zone_getdb()");

    result = dns_db_newversion(*db, version);
    check_result(result, "dns_db_newversion()");
}

/*
 * Finds all public zone keys in the zone, and attempts to load the
 * private keys from disk.
 */
static void
loadzonekeys(dns_db_t *db, dns_dbversion_t *version) {
    dns_name_t *origin;
    dns_dbnode_t *node;
    isc_result_t result;
    dst_key_t *keys[20];
    unsigned int nkeys, i;

    origin = dns_db_origin(db);

    node = NULL;
    result = dns_db_findnode(db, origin, ISC_FALSE, &node);
    check_result(result, "dns_db_findnode()");

    result = dns_dnssec_findzonekeys(db, version, node, origin, mctx,
                     20, keys, &nkeys);
    if (result == ISC_R_NOTFOUND)
        result = ISC_R_SUCCESS;
    check_result(result, "dns_dnssec_findzonekeys()");

    for (i = 0; i < nkeys; i++) {
        signer_key_t *key;

        key = isc_mem_get(mctx, sizeof(signer_key_t));
        if (key == NULL)
            check_result(ISC_R_FAILURE, "isc_mem_get(key)");
        key->key = keys[i];
        key->isdefault = ISC_FALSE;

        ISC_LIST_APPEND(keylist, key, link);
    }
    dns_db_detachnode(db, &node);
}

static void
dumpzone(dns_zone_t *zone, char *filename) {
    isc_result_t result;
    FILE *fp;

    fp = fopen(filename, "w");
    if (fp == NULL) {
        fprintf(stderr, "failure opening %s\n", filename);
        exit(-1);
    }
    result = dns_zone_dumptostream(zone, fp);
    check_result(result, "dns_zone_dump");
    fclose(fp);
}

static isc_stdtime_t
strtotime(char *str, isc_int64_t now, isc_int64_t base) {
    isc_int64_t val, offset;
    isc_result_t result;
    char *endp = "";

    if (str[0] == '+') {
        offset = strtol(str + 1, &endp, 0);
        val = base + offset;
    }
    else if (strncmp(str, "now+", 4) == 0) {
        offset = strtol(str + 4, &endp, 0);
        val = now + offset;
    }
    else {
        result = dns_time64_fromtext(str, &val);
        check_result(result, "dns_time64_fromtext()");
    }
    if (*endp != '\0')
        check_result(ISC_R_FAILURE, "strtol()");

    return ((isc_stdtime_t) val);
}

static void
usage() {
    fprintf(stderr, "Usage:\n");
    fprintf(stderr, "\tsigner [options] zonefile [keys]\n");

    fprintf(stderr, "\n");

    fprintf(stderr, "Options: (default value in parenthesis) \n");
    fprintf(stderr, "\t-s YYYYMMDDHHMMSS|+offset:\n");
    fprintf(stderr, "\t\tSIG start time - absolute|offset (now)\n");
    fprintf(stderr, "\t-e YYYYMMDDHHMMSS|+offset|\"now\"+offset]:\n");
    fprintf(stderr, "\t\tSIG end time  - absolute|from start|from now (now + 30 days)\n");
    fprintf(stderr, "\t-c ttl:\n");
    fprintf(stderr, "\t\tcycle period - regenerate if < cycle from end ( (end-start)/4 )\n");
    fprintf(stderr, "\t-v level:\n");
    fprintf(stderr, "\t\tverbose level (0)\n");
    fprintf(stderr, "\t-o origin:\n");
    fprintf(stderr, "\t\tzone origin (name of zonefile)\n");
    fprintf(stderr, "\t-f outfile:\n");
    fprintf(stderr, "\t\tfile the signed zone is written in " \
            "(zonefile + .signed)\n");
    fprintf(stderr, "\t-a:\n");
    fprintf(stderr, "\t\tverify generated signatures (if currently valid)\n");

    fprintf(stderr, "\n");

    fprintf(stderr, "Signing Keys: ");
    fprintf(stderr, "(default: all zone keys that have private keys)\n");
    fprintf(stderr, "\tid:\t\t");
    fprintf(stderr, "zone key with matching keyid\n");
    fprintf(stderr, "\tid/alg:\t\t");
    fprintf(stderr, "zone key with matching keyid and algorithm\n");
    fprintf(stderr, "\tname/id/alg:\t");
    fprintf(stderr, "key with matching name, keyid and algorithm\n");
    exit(0);
}

int
main(int argc, char *argv[]) {
    int i, ch;
    char *startstr = NULL, *endstr = NULL;
    char *origin = NULL, *file = NULL, *output = NULL;
    char *endp;
    dns_zone_t *zone;
    dns_db_t *db;
    dns_dbversion_t *version;
    signer_key_t *key;
    isc_result_t result;
    isc_log_t *log = NULL;
    isc_logconfig_t *logconfig;

    dns_result_register();

    result = isc_mem_create(0, 0, &mctx);
    check_result(result, "isc_mem_create()");

    while ((ch = isc_commandline_parse(argc, argv, "s:e:c:v:o:f:ah")) != -1)
    {
        switch (ch) {
        case 's':
            startstr = isc_mem_strdup(mctx,
                          isc_commandline_argument);
            if (startstr == NULL)
                check_result(ISC_R_FAILURE, "isc_mem_strdup()");
            break;

        case 'e':
            endstr = isc_mem_strdup(mctx,
                        isc_commandline_argument);
            if (endstr == NULL)
                check_result(ISC_R_FAILURE, "isc_mem_strdup()");
            break;

        case 'c':
            endp = NULL;
            cycle = strtol(isc_commandline_argument, &endp, 0);
            if (*endp != '\0')
                check_result(ISC_R_FAILURE, "strtol()");
            break;

        case 'v':
            endp = NULL;
            verbose = strtol(isc_commandline_argument, &endp, 0);
            if (*endp != '\0')
                check_result(ISC_R_FAILURE, "strtol()");
            break;

        case 'o':
            origin = isc_mem_strdup(mctx,
                        isc_commandline_argument);
            if (origin == NULL)
                check_result(ISC_R_FAILURE, "isc_mem_strdup()");
            break;

        case 'f':
            output = isc_mem_strdup(mctx,
                        isc_commandline_argument);
            if (output == NULL)
                check_result(ISC_R_FAILURE, "isc_mem_strdup()");
            break;

        case 'a':
            tryverify = 1;
            break;

        case 'h':
        default:
            usage();

        }
    }

    isc_stdtime_get(&now);

    if (startstr != NULL) {
        starttime = strtotime(startstr, now, now);
        isc_mem_free(mctx, startstr);
    }
    else
        starttime = now;

    if (endstr != NULL) {
        endtime = strtotime(endstr, now, starttime);
        isc_mem_free(mctx, endstr);
    }
    else
        endtime = starttime + (30 * 24 * 60 * 60);

    if (cycle == -1) {
        cycle = (endtime - starttime) / 4;
    }

    if (verbose > 0) {
        RUNTIME_CHECK(isc_log_create(mctx, &log, &logconfig)
                  == ISC_R_SUCCESS);
        dns_log_init(log);
        RUNTIME_CHECK(isc_log_usechannel(logconfig, "default_stderr",
                         NULL, NULL) == ISC_R_SUCCESS);
    }

    argc -= isc_commandline_index;
    argv += isc_commandline_index;

    if (argc < 1)
        usage();

    file = isc_mem_strdup(mctx, argv[0]);
    if (file == NULL)
        check_result(ISC_R_FAILURE, "isc_mem_strdup()");

    argc -= 1;
    argv += 1;

    if (output == NULL) {
        output = isc_mem_allocate(mctx,
                      strlen(file) + strlen(".signed") + 1);
        if (output == NULL)
            check_result(ISC_R_FAILURE, "isc_mem_allocate()");
        sprintf(output, "%s.signed", file);
    }

    if (origin == NULL) {
        origin = isc_mem_allocate(mctx, strlen(file) + 2);
        if (origin == NULL)
            check_result(ISC_R_FAILURE, "isc_mem_allocate()");
        strcpy(origin, file);
        if (file[strlen(file) - 1] != '.')
            strcat(origin, ".");
    }

    zone = NULL;
    loadzone(file, origin, &zone);

    db = NULL;
    version = NULL;
    getdb(zone, &db, &version);

    ISC_LIST_INIT(keylist);
    loadzonekeys(db, version);

    if (argc == 0) {
        signer_key_t *key;

        key = ISC_LIST_HEAD(keylist);
        while (key != NULL) {
            key->isdefault = ISC_TRUE;
            key = ISC_LIST_NEXT(key, link);
        }
    }
    else {
        for (i = 0; i < argc; i++) {
            int id, alg;
            char *idstr = NULL, *name = NULL, *algstr = NULL, *s;

            idstr = argv[i];
            algstr = strchr(idstr, '/');
            if (algstr != NULL) {
                *algstr++ = 0;
                s = strchr(algstr, '/');
                if (s != NULL) {
                    *s++ = 0;
                    name = idstr;
                    idstr = algstr;
                    algstr = s;
                }
            }

            endp = NULL;
            id = strtol(idstr, &endp, 0);
            if (*endp != '\0')
                check_result(ISC_R_FAILURE, "strtol");

            if (algstr != NULL) {
                endp = NULL;
                alg = strtol(algstr, &endp, 0);
                if (*endp != '\0')
                    check_result(ISC_R_FAILURE, "strtol");
            }
            else
                alg = 0;

            if (name == NULL)
                name = origin;
            key = ISC_LIST_HEAD(keylist);
            while (key != NULL) {
                dst_key_t *dkey = key->key;
                if (dst_key_id(dkey) == id &&
                    (alg == 0 || dst_key_alg(dkey) == alg) &&
                    strcasecmp(name, dst_key_name(dkey)) == 0)
                {
                    key->isdefault = ISC_TRUE;
                    if (!dst_key_isprivate(dkey))
                        check_result
                            (DST_R_NOTPRIVATEKEY,
                             "key specify");
                    if (alg == 0)
                        alg = dst_key_alg(dkey);
                    break;
                }
                key = ISC_LIST_NEXT(key, link);
            }
            if (key == NULL && alg != 0) {
                dst_key_t *dkey = NULL;
                result = dst_key_fromfile(name, id, alg,
                              DST_TYPE_PRIVATE,
                              mctx, &dkey);
                check_result (result, "dst_key_fromfile");
                key = isc_mem_get(mctx, sizeof(signer_key_t));
                if (key == NULL)
                    check_result(ISC_R_FAILURE,
                             "isc_mem_get");
                key->key = dkey;
                key->isdefault = ISC_TRUE;
                ISC_LIST_APPEND(keylist, key, link);
            }
            else
                printf("Ignoring key with algorithm 0\n");
        }
    }

    signzone(db, version);

    /* should we update the SOA serial? */
    dns_db_closeversion(db, &version, ISC_TRUE);
    dumpzone(zone, output);
    dns_db_detach(&db);
    dns_zone_detach(&zone);

    key = ISC_LIST_HEAD(keylist);
    while (key != NULL) {
        signer_key_t *next = ISC_LIST_NEXT(key, link);
        dst_key_free(key->key);
        isc_mem_put(mctx, key, sizeof(signer_key_t));
        key = next;
    }

    isc_mem_free(mctx, origin);
    isc_mem_free(mctx, file);
    isc_mem_free(mctx, output);

    if (log != NULL)
        isc_log_destroy(&log);
/*  isc_mem_stats(mctx, stdout);*/
    isc_mem_destroy(&mctx);

    return (0);
}