lib/dns/dst_parse.c

	dst_parse.c revision e20788e1216ed720aefa84f3295f7899d9f28c22
/*
 * Portions Copyright (C) 2004-2014  Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC AND NETWORK ASSOCIATES DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 *
 * Portions Copyright (C) 1995-2000 by Network Associates, Inc.
 *
 * Permission to use, copy, modify, and/or 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 ISC AND NETWORK ASSOCIATES DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/*%
 * Principal Author: Brian Wellington
 * $Id: dst_parse.c,v 1.29 2011/08/18 23:46:35 tbox Exp $
 */

#include <config.h>

#include <isc/base64.h>
#include <isc/dir.h>
#include <isc/fsaccess.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/stdtime.h>
#include <isc/string.h>
#include <isc/util.h>
#include <isc/file.h>

#include <dns/time.h>
#include <dns/log.h>

#include "dst_internal.h"
#include "dst_parse.h"
#include "dst/result.h"

#define DST_AS_STR(t) ((t).value.as_textregion.base)

#define PRIVATE_KEY_STR "Private-key-format:"
#define ALGORITHM_STR "Algorithm:"

#define TIMING_NTAGS (DST_MAX_TIMES + 1)
static const char *timetags[TIMING_NTAGS] = {
    "Created:",
    "Publish:",
    "Activate:",
    "Revoke:",
    "Inactive:",
    "Delete:",
    "DSPublish:"
};

#define NUMERIC_NTAGS (DST_MAX_NUMERIC + 1)
static const char *numerictags[NUMERIC_NTAGS] = {
    "Predecessor:",
    "Successor:",
    "MaxTTL:",
    "RollPeriod:"
};

struct parse_map {
    const int value;
    const char *tag;
};

static struct parse_map map[] = {
    {TAG_RSA_MODULUS, "Modulus:"},
    {TAG_RSA_PUBLICEXPONENT, "PublicExponent:"},
    {TAG_RSA_PRIVATEEXPONENT, "PrivateExponent:"},
    {TAG_RSA_PRIME1, "Prime1:"},
    {TAG_RSA_PRIME2, "Prime2:"},
    {TAG_RSA_EXPONENT1, "Exponent1:"},
    {TAG_RSA_EXPONENT2, "Exponent2:"},
    {TAG_RSA_COEFFICIENT, "Coefficient:"},
    {TAG_RSA_ENGINE, "Engine:" },
    {TAG_RSA_LABEL, "Label:" },

    {TAG_DH_PRIME, "Prime(p):"},
    {TAG_DH_GENERATOR, "Generator(g):"},
    {TAG_DH_PRIVATE, "Private_value(x):"},
    {TAG_DH_PUBLIC, "Public_value(y):"},

    {TAG_DSA_PRIME, "Prime(p):"},
    {TAG_DSA_SUBPRIME, "Subprime(q):"},
    {TAG_DSA_BASE, "Base(g):"},
    {TAG_DSA_PRIVATE, "Private_value(x):"},
    {TAG_DSA_PUBLIC, "Public_value(y):"},

    {TAG_GOST_PRIVASN1, "GostAsn1:"},
    {TAG_GOST_PRIVRAW, "PrivateKey:"},

    {TAG_ECDSA_PRIVATEKEY, "PrivateKey:"},
    {TAG_ECDSA_ENGINE, "Engine:" },
    {TAG_ECDSA_LABEL, "Label:" },

    {TAG_HMACMD5_KEY, "Key:"},
    {TAG_HMACMD5_BITS, "Bits:"},

    {TAG_HMACSHA1_KEY, "Key:"},
    {TAG_HMACSHA1_BITS, "Bits:"},

    {TAG_HMACSHA224_KEY, "Key:"},
    {TAG_HMACSHA224_BITS, "Bits:"},

    {TAG_HMACSHA256_KEY, "Key:"},
    {TAG_HMACSHA256_BITS, "Bits:"},

    {TAG_HMACSHA384_KEY, "Key:"},
    {TAG_HMACSHA384_BITS, "Bits:"},

    {TAG_HMACSHA512_KEY, "Key:"},
    {TAG_HMACSHA512_BITS, "Bits:"},

    {0, NULL}
};

static int
find_value(const char *s, const unsigned int alg) {
    int i;

    for (i = 0; map[i].tag != NULL; i++) {
        if (strcasecmp(s, map[i].tag) == 0 &&
            (TAG_ALG(map[i].value) == alg))
            return (map[i].value);
    }
    return (-1);
}

static const char *
find_tag(const int value) {
    int i;

    for (i = 0; ; i++) {
        if (map[i].tag == NULL)
            return (NULL);
        else if (value == map[i].value)
            return (map[i].tag);
    }
}

static int
find_metadata(const char *s, const char *tags[], int ntags) {
    int i;

    for (i = 0; i < ntags; i++) {
        if (strcasecmp(s, tags[i]) == 0)
            return (i);
    }

    return (-1);
}

static int
find_timedata(const char *s) {
    return (find_metadata(s, timetags, TIMING_NTAGS));
}

static int
find_numericdata(const char *s) {
    return (find_metadata(s, numerictags, NUMERIC_NTAGS));
}

static int
check_rsa(const dst_private_t *priv, isc_boolean_t external) {
    int i, j;
    isc_boolean_t have[RSA_NTAGS];
    isc_boolean_t ok;
    unsigned int mask;

    if (external)
        return ((priv->nelements == 0) ? 0 : -1);

    for (i = 0; i < RSA_NTAGS; i++)
        have[i] = ISC_FALSE;

    for (j = 0; j < priv->nelements; j++) {
        for (i = 0; i < RSA_NTAGS; i++)
            if (priv->elements[j].tag == TAG(DST_ALG_RSAMD5, i))
                break;
        if (i == RSA_NTAGS)
            return (-1);
        have[i] = ISC_TRUE;
    }

    mask = ~0;
    mask <<= sizeof(mask) * 8 - TAG_SHIFT;
    mask >>= sizeof(mask) * 8 - TAG_SHIFT;

    if (have[TAG_RSA_ENGINE & mask])
        ok = have[TAG_RSA_MODULUS & mask] &&
             have[TAG_RSA_PUBLICEXPONENT & mask] &&
             have[TAG_RSA_LABEL & mask];
    else
        ok = have[TAG_RSA_MODULUS & mask] &&
             have[TAG_RSA_PUBLICEXPONENT & mask] &&
             have[TAG_RSA_PRIVATEEXPONENT & mask] &&
             have[TAG_RSA_PRIME1 & mask] &&
             have[TAG_RSA_PRIME2 & mask] &&
             have[TAG_RSA_EXPONENT1 & mask] &&
             have[TAG_RSA_EXPONENT2 & mask] &&
             have[TAG_RSA_COEFFICIENT & mask];
    return (ok ? 0 : -1 );
}

static int
check_dh(const dst_private_t *priv) {
    int i, j;
    if (priv->nelements != DH_NTAGS)
        return (-1);
    for (i = 0; i < DH_NTAGS; i++) {
        for (j = 0; j < priv->nelements; j++)
            if (priv->elements[j].tag == TAG(DST_ALG_DH, i))
                break;
        if (j == priv->nelements)
            return (-1);
    }
    return (0);
}

static int
check_dsa(const dst_private_t *priv, isc_boolean_t external) {
    int i, j;

    if (external)
        return ((priv->nelements == 0)? 0 : -1);

    if (priv->nelements != DSA_NTAGS)
        return (-1);

    for (i = 0; i < DSA_NTAGS; i++) {
        for (j = 0; j < priv->nelements; j++)
            if (priv->elements[j].tag == TAG(DST_ALG_DSA, i))
                break;
        if (j == priv->nelements)
            return (-1);
    }
    return (0);
}

static int
check_gost(const dst_private_t *priv, isc_boolean_t external) {

    if (external)
        return ((priv->nelements == 0)? 0 : -1);

    if (priv->nelements != GOST_NTAGS)
        return (-1);
    if ((priv->elements[0].tag != TAG(DST_ALG_ECCGOST, 0)) &&
        (priv->elements[0].tag != TAG(DST_ALG_ECCGOST, 1)))
        return (-1);
    return (0);
}

static int
check_ecdsa(const dst_private_t *priv, isc_boolean_t external) {
    int i, j;
    isc_boolean_t have[ECDSA_NTAGS];
    isc_boolean_t ok;
    unsigned int mask;

    if (external)
        return ((priv->nelements == 0) ? 0 : -1);

    for (i = 0; i < ECDSA_NTAGS; i++)
        have[i] = ISC_FALSE;
    for (j = 0; j < priv->nelements; j++) {
        for (i = 0; i < ECDSA_NTAGS; i++)
            if (priv->elements[j].tag == TAG(DST_ALG_ECDSA256, i))
                break;
        if (i == ECDSA_NTAGS)
            return (-1);
        have[i] = ISC_TRUE;
    }

    mask = ~0;
    mask <<= sizeof(mask) * 8 - TAG_SHIFT;
    mask >>= sizeof(mask) * 8 - TAG_SHIFT;

    if (have[TAG_ECDSA_ENGINE & mask])
        ok = have[TAG_ECDSA_LABEL & mask];
    else
        ok = have[TAG_ECDSA_PRIVATEKEY & mask];
    return (ok ? 0 : -1 );
}

static int
check_hmac_md5(const dst_private_t *priv, isc_boolean_t old) {
    int i, j;

    if (priv->nelements != HMACMD5_NTAGS) {
        /*
         * If this is a good old format and we are accepting
         * the old format return success.
         */
        if (old && priv->nelements == OLD_HMACMD5_NTAGS &&
            priv->elements[0].tag == TAG_HMACMD5_KEY)
            return (0);
        return (-1);
    }
    /*
     * We must be new format at this point.
     */
    for (i = 0; i < HMACMD5_NTAGS; i++) {
        for (j = 0; j < priv->nelements; j++)
            if (priv->elements[j].tag == TAG(DST_ALG_HMACMD5, i))
                break;
        if (j == priv->nelements)
            return (-1);
    }
    return (0);
}

static int
check_hmac_sha(const dst_private_t *priv, unsigned int ntags,
           unsigned int alg)
{
    unsigned int i, j;
    if (priv->nelements != ntags)
        return (-1);
    for (i = 0; i < ntags; i++) {
        for (j = 0; j < priv->nelements; j++)
            if (priv->elements[j].tag == TAG(alg, i))
                break;
        if (j == priv->nelements)
            return (-1);
    }
    return (0);
}

static int
check_data(const dst_private_t *priv, const unsigned int alg,
       isc_boolean_t old, isc_boolean_t external)
{
    /* XXXVIX this switch statement is too sparse to gen a jump table. */
    switch (alg) {
    case DST_ALG_RSAMD5:
    case DST_ALG_RSASHA1:
    case DST_ALG_NSEC3RSASHA1:
    case DST_ALG_RSASHA256:
    case DST_ALG_RSASHA512:
        return (check_rsa(priv, external));
    case DST_ALG_DH:
        return (check_dh(priv));
    case DST_ALG_DSA:
    case DST_ALG_NSEC3DSA:
        return (check_dsa(priv, external));
    case DST_ALG_ECCGOST:
        return (check_gost(priv, external));
    case DST_ALG_ECDSA256:
    case DST_ALG_ECDSA384:
        return (check_ecdsa(priv, external));
    case DST_ALG_HMACMD5:
        return (check_hmac_md5(priv, old));
    case DST_ALG_HMACSHA1:
        return (check_hmac_sha(priv, HMACSHA1_NTAGS, alg));
    case DST_ALG_HMACSHA224:
        return (check_hmac_sha(priv, HMACSHA224_NTAGS, alg));
    case DST_ALG_HMACSHA256:
        return (check_hmac_sha(priv, HMACSHA256_NTAGS, alg));
    case DST_ALG_HMACSHA384:
        return (check_hmac_sha(priv, HMACSHA384_NTAGS, alg));
    case DST_ALG_HMACSHA512:
        return (check_hmac_sha(priv, HMACSHA512_NTAGS, alg));
    default:
        return (DST_R_UNSUPPORTEDALG);
    }
}

void
dst__privstruct_free(dst_private_t *priv, isc_mem_t *mctx) {
    int i;

    if (priv == NULL)
        return;
    for (i = 0; i < priv->nelements; i++) {
        if (priv->elements[i].data == NULL)
            continue;
        memset(priv->elements[i].data, 0, MAXFIELDSIZE);
        isc_mem_put(mctx, priv->elements[i].data, MAXFIELDSIZE);
    }
    priv->nelements = 0;
}

isc_result_t
dst__privstruct_parse(dst_key_t *key, unsigned int alg, isc_lex_t *lex,
              isc_mem_t *mctx, dst_private_t *priv)
{
    int n = 0, major, minor, check;
    isc_buffer_t b;
    isc_token_t token;
    unsigned char *data = NULL;
    unsigned int opt = ISC_LEXOPT_EOL;
    isc_stdtime_t when;
    isc_result_t ret;
    isc_boolean_t external = ISC_FALSE;

    REQUIRE(priv != NULL);

    priv->nelements = 0;
    memset(priv->elements, 0, sizeof(priv->elements));

#define NEXTTOKEN(lex, opt, token)              \
    do {                            \
        ret = isc_lex_gettoken(lex, opt, token);    \
        if (ret != ISC_R_SUCCESS)           \
            goto fail;              \
    } while (0)

#define READLINE(lex, opt, token)               \
    do {                            \
        ret = isc_lex_gettoken(lex, opt, token);    \
        if (ret == ISC_R_EOF)               \
            break;                  \
        else if (ret != ISC_R_SUCCESS)          \
            goto fail;              \
    } while ((*token).type != isc_tokentype_eol)

    /*
     * Read the description line.
     */
    NEXTTOKEN(lex, opt, &token);
    if (token.type != isc_tokentype_string ||
        strcmp(DST_AS_STR(token), PRIVATE_KEY_STR) != 0)
    {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    NEXTTOKEN(lex, opt, &token);
    if (token.type != isc_tokentype_string ||
        (DST_AS_STR(token))[0] != 'v')
    {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }
    if (sscanf(DST_AS_STR(token), "v%d.%d", &major, &minor) != 2)
    {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    if (major > DST_MAJOR_VERSION) {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    /*
     * Store the private key format version number
     */
    dst_key_setprivateformat(key, major, minor);

    READLINE(lex, opt, &token);

    /*
     * Read the algorithm line.
     */
    NEXTTOKEN(lex, opt, &token);
    if (token.type != isc_tokentype_string ||
        strcmp(DST_AS_STR(token), ALGORITHM_STR) != 0)
    {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    NEXTTOKEN(lex, opt | ISC_LEXOPT_NUMBER, &token);
    if (token.type != isc_tokentype_number ||
        token.value.as_ulong != (unsigned long) dst_key_alg(key))
    {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    READLINE(lex, opt, &token);

    /*
     * Read the key data.
     */
    for (n = 0; n < MAXFIELDS; n++) {
        int tag;
        isc_region_t r;
        do {
            ret = isc_lex_gettoken(lex, opt, &token);
            if (ret == ISC_R_EOF)
                goto done;
            if (ret != ISC_R_SUCCESS)
                goto fail;
        } while (token.type == isc_tokentype_eol);

        if (token.type != isc_tokentype_string) {
            ret = DST_R_INVALIDPRIVATEKEY;
            goto fail;
        }

        if (strcmp(DST_AS_STR(token), "External:") == 0) {
            external = ISC_TRUE;
            goto next;
        }

        /* Numeric metadata */
        tag = find_numericdata(DST_AS_STR(token));
        if (tag >= 0) {
            INSIST(tag < NUMERIC_NTAGS);

            NEXTTOKEN(lex, opt | ISC_LEXOPT_NUMBER, &token);
            if (token.type != isc_tokentype_number) {
                ret = DST_R_INVALIDPRIVATEKEY;
                goto fail;
            }

            dst_key_setnum(key, tag, token.value.as_ulong);
            goto next;
        }

        /* Timing metadata */
        tag = find_timedata(DST_AS_STR(token));
        if (tag >= 0) {
            INSIST(tag < TIMING_NTAGS);

            NEXTTOKEN(lex, opt, &token);
            if (token.type != isc_tokentype_string) {
                ret = DST_R_INVALIDPRIVATEKEY;
                goto fail;
            }

            ret = dns_time32_fromtext(DST_AS_STR(token), &when);
            if (ret != ISC_R_SUCCESS)
                goto fail;

            dst_key_settime(key, tag, when);

            goto next;
        }

        /* Key data */
        tag = find_value(DST_AS_STR(token), alg);
        if (tag < 0 && minor > DST_MINOR_VERSION)
            goto next;
        else if (tag < 0) {
            ret = DST_R_INVALIDPRIVATEKEY;
            goto fail;
        }

        priv->elements[n].tag = tag;

        data = (unsigned char *) isc_mem_get(mctx, MAXFIELDSIZE);
        if (data == NULL)
            goto fail;

        isc_buffer_init(&b, data, MAXFIELDSIZE);
        ret = isc_base64_tobuffer(lex, &b, -1);
        if (ret != ISC_R_SUCCESS)
            goto fail;

        isc_buffer_usedregion(&b, &r);
        priv->elements[n].length = r.length;
        priv->elements[n].data = r.base;
        priv->nelements++;

      next:
        READLINE(lex, opt, &token);
        data = NULL;
    }

 done:
    if (external && priv->nelements != 0) {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    }

    check = check_data(priv, alg, ISC_TRUE, external);
    if (check < 0) {
        ret = DST_R_INVALIDPRIVATEKEY;
        goto fail;
    } else if (check != ISC_R_SUCCESS) {
        ret = check;
        goto fail;
    }

    key->external = external;

    return (ISC_R_SUCCESS);

fail:
    dst__privstruct_free(priv, mctx);
    if (data != NULL)
        isc_mem_put(mctx, data, MAXFIELDSIZE);

    return (ret);
}

isc_result_t
dst__privstruct_writefile(const dst_key_t *key, const dst_private_t *priv,
              const char *directory)
{
    FILE *fp;
    isc_result_t result;
    char filename[ISC_DIR_NAMEMAX];
    char buffer[MAXFIELDSIZE * 2];
    isc_fsaccess_t access;
    isc_stdtime_t when;
    isc_uint32_t value;
    isc_buffer_t b;
    isc_region_t r;
    int major, minor;
    mode_t mode;
    int i, ret;

    REQUIRE(priv != NULL);

    ret = check_data(priv, dst_key_alg(key), ISC_FALSE, key->external);
    if (ret < 0)
        return (DST_R_INVALIDPRIVATEKEY);
    else if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, filename, sizeof(filename));
    result = dst_key_buildfilename(key, DST_TYPE_PRIVATE, directory, &b);
    if (result != ISC_R_SUCCESS)
        return (result);

    result = isc_file_mode(filename, &mode);
    if (result == ISC_R_SUCCESS && mode != 0600) {
        /* File exists; warn that we are changing its permissions */
        isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
                  DNS_LOGMODULE_DNSSEC, ISC_LOG_WARNING,
                  "Permissions on the file %s "
                  "have changed from 0%o to 0600 as "
                  "a result of this operation.",
                  filename, (unsigned int)mode);
    }

    if ((fp = fopen(filename, "w")) == NULL)
        return (DST_R_WRITEERROR);

    access = 0;
    isc_fsaccess_add(ISC_FSACCESS_OWNER,
             ISC_FSACCESS_READ | ISC_FSACCESS_WRITE,
             &access);
    (void)isc_fsaccess_set(filename, access);

    dst_key_getprivateformat(key, &major, &minor);
    if (major == 0 && minor == 0) {
        major = DST_MAJOR_VERSION;
        minor = DST_MINOR_VERSION;
    }

    /* XXXDCL return value should be checked for full filesystem */
    fprintf(fp, "%s v%d.%d\n", PRIVATE_KEY_STR, major, minor);

    fprintf(fp, "%s %d ", ALGORITHM_STR, dst_key_alg(key));

    /* XXXVIX this switch statement is too sparse to gen a jump table. */
    switch (dst_key_alg(key)) {
    case DST_ALG_RSAMD5:
        fprintf(fp, "(RSA)\n");
        break;
    case DST_ALG_DH:
        fprintf(fp, "(DH)\n");
        break;
    case DST_ALG_DSA:
        fprintf(fp, "(DSA)\n");
        break;
    case DST_ALG_RSASHA1:
        fprintf(fp, "(RSASHA1)\n");
        break;
    case DST_ALG_NSEC3RSASHA1:
        fprintf(fp, "(NSEC3RSASHA1)\n");
        break;
    case DST_ALG_NSEC3DSA:
        fprintf(fp, "(NSEC3DSA)\n");
        break;
    case DST_ALG_RSASHA256:
        fprintf(fp, "(RSASHA256)\n");
        break;
    case DST_ALG_RSASHA512:
        fprintf(fp, "(RSASHA512)\n");
        break;
    case DST_ALG_ECCGOST:
        fprintf(fp, "(ECC-GOST)\n");
        break;
    case DST_ALG_ECDSA256:
        fprintf(fp, "(ECDSAP256SHA256)\n");
        break;
    case DST_ALG_ECDSA384:
        fprintf(fp, "(ECDSAP384SHA384)\n");
        break;
    case DST_ALG_HMACMD5:
        fprintf(fp, "(HMAC_MD5)\n");
        break;
    case DST_ALG_HMACSHA1:
        fprintf(fp, "(HMAC_SHA1)\n");
        break;
    case DST_ALG_HMACSHA224:
        fprintf(fp, "(HMAC_SHA224)\n");
        break;
    case DST_ALG_HMACSHA256:
        fprintf(fp, "(HMAC_SHA256)\n");
        break;
    case DST_ALG_HMACSHA384:
        fprintf(fp, "(HMAC_SHA384)\n");
        break;
    case DST_ALG_HMACSHA512:
        fprintf(fp, "(HMAC_SHA512)\n");
        break;
    default:
        fprintf(fp, "(?)\n");
        break;
    }

    for (i = 0; i < priv->nelements; i++) {
        const char *s;

        s = find_tag(priv->elements[i].tag);

        r.base = priv->elements[i].data;
        r.length = priv->elements[i].length;
        isc_buffer_init(&b, buffer, sizeof(buffer));
        result = isc_base64_totext(&r, sizeof(buffer), "", &b);
        if (result != ISC_R_SUCCESS) {
            fclose(fp);
            return (DST_R_INVALIDPRIVATEKEY);
        }
        isc_buffer_usedregion(&b, &r);

           fprintf(fp, "%s %.*s\n", s, (int)r.length, r.base);
    }

    if (key->external)
           fprintf(fp, "External:\n");

    /* Add the metadata tags */
    if (major > 1 || (major == 1 && minor >= 3)) {
        for (i = 0; i < NUMERIC_NTAGS; i++) {
            result = dst_key_getnum(key, i, &value);
            if (result != ISC_R_SUCCESS)
                continue;
            fprintf(fp, "%s %u\n", numerictags[i], value);
        }
        for (i = 0; i < TIMING_NTAGS; i++) {
            result = dst_key_gettime(key, i, &when);
            if (result != ISC_R_SUCCESS)
                continue;

            isc_buffer_init(&b, buffer, sizeof(buffer));
            result = dns_time32_totext(when, &b);
            if (result != ISC_R_SUCCESS) {
                   fclose(fp);
                   return (DST_R_INVALIDPRIVATEKEY);
            }

            isc_buffer_usedregion(&b, &r);

            fprintf(fp, "%s %.*s\n", timetags[i], (int)r.length,
                r.base);
        }
    }

    fflush(fp);
    result = ferror(fp) ? DST_R_WRITEERROR : ISC_R_SUCCESS;
    fclose(fp);
    return (result);
}

/*! \file */