lib/dns/hmac_link.c

/*
 * Portions Copyright (C) 1999-2002, 2004-2018  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * 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
 */

#include <config.h>

#include <isc/buffer.h>
#include <isc/hmacmd5.h>
#include <isc/hmacsha.h>
#include <isc/md5.h>
#include <isc/sha1.h>
#include <isc/mem.h>
#include <isc/safe.h>
#include <isc/string.h>
#include <isc/util.h>

#include <pk11/site.h>

#include <dst/result.h>

#include "dst_internal.h"
#ifdef HAVE_FIPS_MODE
#include "dst_openssl.h"    /* FIPS_mode() prototype */
#endif
#include "dst_parse.h"

#ifndef PK11_MD5_DISABLE
static isc_result_t hmacmd5_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacmd5_key {
    unsigned char key[ISC_MD5_BLOCK_LENGTH];
};
#endif

static isc_result_t
getkeybits(dst_key_t *key, struct dst_private_element *element) {

    if (element->length != 2)
        return (DST_R_INVALIDPRIVATEKEY);

    key->key_bits = (element->data[0] << 8) + element->data[1];

    return (ISC_R_SUCCESS);
}

#ifndef PK11_MD5_DISABLE
static isc_result_t
hmacmd5_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacmd5_t *hmacmd5ctx;
    dst_hmacmd5_key_t *hkey = key->keydata.hmacmd5;

    hmacmd5ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacmd5_t));
    if (hmacmd5ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacmd5_init(hmacmd5ctx, hkey->key, ISC_MD5_BLOCK_LENGTH);
    dctx->ctxdata.hmacmd5ctx = hmacmd5ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacmd5_destroyctx(dst_context_t *dctx) {
    isc_hmacmd5_t *hmacmd5ctx = dctx->ctxdata.hmacmd5ctx;

    if (hmacmd5ctx != NULL) {
        isc_hmacmd5_invalidate(hmacmd5ctx);
        isc_mem_put(dctx->mctx, hmacmd5ctx, sizeof(isc_hmacmd5_t));
        dctx->ctxdata.hmacmd5ctx = NULL;
    }
}

static isc_result_t
hmacmd5_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacmd5_t *hmacmd5ctx = dctx->ctxdata.hmacmd5ctx;

    isc_hmacmd5_update(hmacmd5ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacmd5_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacmd5_t *hmacmd5ctx = dctx->ctxdata.hmacmd5ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_MD5_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacmd5_sign(hmacmd5ctx, digest);
    isc_buffer_add(sig, ISC_MD5_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacmd5_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacmd5_t *hmacmd5ctx = dctx->ctxdata.hmacmd5ctx;

    if (sig->length > ISC_MD5_DIGESTLENGTH)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacmd5_verify2(hmacmd5ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacmd5_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacmd5_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacmd5;
    hkey2 = key2->keydata.hmacmd5;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_MD5_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacmd5_generate(dst_key_t *key, int pseudorandom_ok, void (*callback)(int)) {
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_MD5_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_MD5_BLOCK_LENGTH) {
        bytes = ISC_MD5_BLOCK_LENGTH;
        key->key_size = ISC_MD5_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_MD5_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacmd5_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacmd5_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacmd5_destroy(dst_key_t *key) {
    dst_hmacmd5_key_t *hkey = key->keydata.hmacmd5;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacmd5 = NULL;
}

static isc_result_t
hmacmd5_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacmd5_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacmd5 != NULL);

    hkey = key->keydata.hmacmd5;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacmd5_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacmd5_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_md5_t md5ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacmd5_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_MD5_BLOCK_LENGTH) {
        isc_md5_init(&md5ctx);
        isc_md5_update(&md5ctx, r.base, r.length);
        isc_md5_final(&md5ctx, hkey->key);
        keylen = ISC_MD5_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacmd5 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacmd5_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacmd5_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacmd5 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacmd5;

    priv.elements[cnt].tag = TAG_HMACMD5_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACMD5_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacmd5_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACMD5, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACMD5_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacmd5_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACMD5_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacmd5_functions = {
    hmacmd5_createctx,
    NULL, /*%< createctx2 */
    hmacmd5_destroyctx,
    hmacmd5_adddata,
    hmacmd5_sign,
    hmacmd5_verify,
    NULL, /*%< verify2 */
    NULL, /*%< computesecret */
    hmacmd5_compare,
    NULL, /*%< paramcompare */
    hmacmd5_generate,
    hmacmd5_isprivate,
    hmacmd5_destroy,
    hmacmd5_todns,
    hmacmd5_fromdns,
    hmacmd5_tofile,
    hmacmd5_parse,
    NULL, /*%< cleanup */
    NULL, /*%< fromlabel */
    NULL, /*%< dump */
    NULL, /*%< restore */
};

isc_result_t
dst__hmacmd5_init(dst_func_t **funcp) {
#ifdef HAVE_FIPS_MODE
    /*
     * Problems from OpenSSL are likely from FIPS mode
     */
    int fips_mode = FIPS_mode();

    if (fips_mode != 0) {
        UNEXPECTED_ERROR(__FILE__, __LINE__,
                 "FIPS mode is %d: MD5 is only supported "
                 "if the value is 0.\n"
                 "Please disable either FIPS mode or MD5.",
                 fips_mode);
    }
#endif

    /*
     * Prevent use of incorrect crypto
     */

    RUNTIME_CHECK(isc_md5_check(ISC_FALSE));
    RUNTIME_CHECK(isc_hmacmd5_check(0));

    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacmd5_functions;
    return (ISC_R_SUCCESS);
}
#endif

static isc_result_t hmacsha1_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacsha1_key {
    unsigned char key[ISC_SHA1_BLOCK_LENGTH];
};

static isc_result_t
hmacsha1_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacsha1_t *hmacsha1ctx;
    dst_hmacsha1_key_t *hkey = key->keydata.hmacsha1;

    hmacsha1ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacsha1_t));
    if (hmacsha1ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacsha1_init(hmacsha1ctx, hkey->key, ISC_SHA1_BLOCK_LENGTH);
    dctx->ctxdata.hmacsha1ctx = hmacsha1ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacsha1_destroyctx(dst_context_t *dctx) {
    isc_hmacsha1_t *hmacsha1ctx = dctx->ctxdata.hmacsha1ctx;

    if (hmacsha1ctx != NULL) {
        isc_hmacsha1_invalidate(hmacsha1ctx);
        isc_mem_put(dctx->mctx, hmacsha1ctx, sizeof(isc_hmacsha1_t));
        dctx->ctxdata.hmacsha1ctx = NULL;
    }
}

static isc_result_t
hmacsha1_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacsha1_t *hmacsha1ctx = dctx->ctxdata.hmacsha1ctx;

    isc_hmacsha1_update(hmacsha1ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha1_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacsha1_t *hmacsha1ctx = dctx->ctxdata.hmacsha1ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_SHA1_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacsha1_sign(hmacsha1ctx, digest, ISC_SHA1_DIGESTLENGTH);
    isc_buffer_add(sig, ISC_SHA1_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha1_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacsha1_t *hmacsha1ctx = dctx->ctxdata.hmacsha1ctx;

    if (sig->length > ISC_SHA1_DIGESTLENGTH || sig->length == 0)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacsha1_verify(hmacsha1ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacsha1_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacsha1_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacsha1;
    hkey2 = key2->keydata.hmacsha1;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_SHA1_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacsha1_generate(dst_key_t *key, int pseudorandom_ok, void (*callback)(int)) {
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_SHA1_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_SHA1_BLOCK_LENGTH) {
        bytes = ISC_SHA1_BLOCK_LENGTH;
        key->key_size = ISC_SHA1_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_SHA1_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacsha1_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacsha1_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacsha1_destroy(dst_key_t *key) {
    dst_hmacsha1_key_t *hkey = key->keydata.hmacsha1;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacsha1 = NULL;
}

static isc_result_t
hmacsha1_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha1_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacsha1 != NULL);

    hkey = key->keydata.hmacsha1;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha1_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha1_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_sha1_t sha1ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacsha1_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_SHA1_BLOCK_LENGTH) {
        isc_sha1_init(&sha1ctx);
        isc_sha1_update(&sha1ctx, r.base, r.length);
        isc_sha1_final(&sha1ctx, hkey->key);
        keylen = ISC_SHA1_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacsha1 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha1_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacsha1_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacsha1 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacsha1;

    priv.elements[cnt].tag = TAG_HMACSHA1_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACSHA1_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacsha1_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACSHA1, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACSHA1_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacsha1_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACSHA1_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacsha1_functions = {
    hmacsha1_createctx,
    NULL, /*%< createctx2 */
    hmacsha1_destroyctx,
    hmacsha1_adddata,
    hmacsha1_sign,
    hmacsha1_verify,
    NULL, /* verify2 */
    NULL, /* computesecret */
    hmacsha1_compare,
    NULL, /* paramcompare */
    hmacsha1_generate,
    hmacsha1_isprivate,
    hmacsha1_destroy,
    hmacsha1_todns,
    hmacsha1_fromdns,
    hmacsha1_tofile,
    hmacsha1_parse,
    NULL, /* cleanup */
    NULL, /* fromlabel */
    NULL, /* dump */
    NULL, /* restore */
};

isc_result_t
dst__hmacsha1_init(dst_func_t **funcp) {
    /*
     * Prevent use of incorrect crypto
     */
    RUNTIME_CHECK(isc_sha1_check(ISC_FALSE));
    RUNTIME_CHECK(isc_hmacsha1_check(0));

    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacsha1_functions;
    return (ISC_R_SUCCESS);
}

static isc_result_t hmacsha224_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacsha224_key {
    unsigned char key[ISC_SHA224_BLOCK_LENGTH];
};

static isc_result_t
hmacsha224_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacsha224_t *hmacsha224ctx;
    dst_hmacsha224_key_t *hkey = key->keydata.hmacsha224;

    hmacsha224ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacsha224_t));
    if (hmacsha224ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacsha224_init(hmacsha224ctx, hkey->key, ISC_SHA224_BLOCK_LENGTH);
    dctx->ctxdata.hmacsha224ctx = hmacsha224ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacsha224_destroyctx(dst_context_t *dctx) {
    isc_hmacsha224_t *hmacsha224ctx = dctx->ctxdata.hmacsha224ctx;

    if (hmacsha224ctx != NULL) {
        isc_hmacsha224_invalidate(hmacsha224ctx);
        isc_mem_put(dctx->mctx, hmacsha224ctx, sizeof(isc_hmacsha224_t));
        dctx->ctxdata.hmacsha224ctx = NULL;
    }
}

static isc_result_t
hmacsha224_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacsha224_t *hmacsha224ctx = dctx->ctxdata.hmacsha224ctx;

    isc_hmacsha224_update(hmacsha224ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha224_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacsha224_t *hmacsha224ctx = dctx->ctxdata.hmacsha224ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_SHA224_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacsha224_sign(hmacsha224ctx, digest, ISC_SHA224_DIGESTLENGTH);
    isc_buffer_add(sig, ISC_SHA224_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha224_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacsha224_t *hmacsha224ctx = dctx->ctxdata.hmacsha224ctx;

    if (sig->length > ISC_SHA224_DIGESTLENGTH || sig->length == 0)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacsha224_verify(hmacsha224ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacsha224_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacsha224_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacsha224;
    hkey2 = key2->keydata.hmacsha224;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_SHA224_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacsha224_generate(dst_key_t *key, int pseudorandom_ok,
            void (*callback)(int))
{
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_SHA224_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_SHA224_BLOCK_LENGTH) {
        bytes = ISC_SHA224_BLOCK_LENGTH;
        key->key_size = ISC_SHA224_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_SHA224_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacsha224_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacsha224_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacsha224_destroy(dst_key_t *key) {
    dst_hmacsha224_key_t *hkey = key->keydata.hmacsha224;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacsha224 = NULL;
}

static isc_result_t
hmacsha224_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha224_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacsha224 != NULL);

    hkey = key->keydata.hmacsha224;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha224_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha224_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_sha224_t sha224ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacsha224_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_SHA224_BLOCK_LENGTH) {
        isc_sha224_init(&sha224ctx);
        isc_sha224_update(&sha224ctx, r.base, r.length);
        isc_sha224_final(hkey->key, &sha224ctx);
        keylen = ISC_SHA224_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacsha224 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha224_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacsha224_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacsha224 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacsha224;

    priv.elements[cnt].tag = TAG_HMACSHA224_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACSHA224_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacsha224_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACSHA224, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACSHA224_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacsha224_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACSHA224_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacsha224_functions = {
    hmacsha224_createctx,
    NULL, /*%< createctx2 */
    hmacsha224_destroyctx,
    hmacsha224_adddata,
    hmacsha224_sign,
    hmacsha224_verify,
    NULL, /* verify2 */
    NULL, /* computesecret */
    hmacsha224_compare,
    NULL, /* paramcompare */
    hmacsha224_generate,
    hmacsha224_isprivate,
    hmacsha224_destroy,
    hmacsha224_todns,
    hmacsha224_fromdns,
    hmacsha224_tofile,
    hmacsha224_parse,
    NULL, /* cleanup */
    NULL, /* fromlabel */
    NULL, /* dump */
    NULL, /* restore */
};

isc_result_t
dst__hmacsha224_init(dst_func_t **funcp) {
    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacsha224_functions;
    return (ISC_R_SUCCESS);
}

static isc_result_t hmacsha256_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacsha256_key {
    unsigned char key[ISC_SHA256_BLOCK_LENGTH];
};

static isc_result_t
hmacsha256_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacsha256_t *hmacsha256ctx;
    dst_hmacsha256_key_t *hkey = key->keydata.hmacsha256;

    hmacsha256ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacsha256_t));
    if (hmacsha256ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacsha256_init(hmacsha256ctx, hkey->key, ISC_SHA256_BLOCK_LENGTH);
    dctx->ctxdata.hmacsha256ctx = hmacsha256ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacsha256_destroyctx(dst_context_t *dctx) {
    isc_hmacsha256_t *hmacsha256ctx = dctx->ctxdata.hmacsha256ctx;

    if (hmacsha256ctx != NULL) {
        isc_hmacsha256_invalidate(hmacsha256ctx);
        isc_mem_put(dctx->mctx, hmacsha256ctx, sizeof(isc_hmacsha256_t));
        dctx->ctxdata.hmacsha256ctx = NULL;
    }
}

static isc_result_t
hmacsha256_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacsha256_t *hmacsha256ctx = dctx->ctxdata.hmacsha256ctx;

    isc_hmacsha256_update(hmacsha256ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha256_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacsha256_t *hmacsha256ctx = dctx->ctxdata.hmacsha256ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_SHA256_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacsha256_sign(hmacsha256ctx, digest, ISC_SHA256_DIGESTLENGTH);
    isc_buffer_add(sig, ISC_SHA256_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha256_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacsha256_t *hmacsha256ctx = dctx->ctxdata.hmacsha256ctx;

    if (sig->length > ISC_SHA256_DIGESTLENGTH || sig->length == 0)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacsha256_verify(hmacsha256ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacsha256_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacsha256_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacsha256;
    hkey2 = key2->keydata.hmacsha256;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_SHA256_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacsha256_generate(dst_key_t *key, int pseudorandom_ok,
            void (*callback)(int))
{
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_SHA256_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_SHA256_BLOCK_LENGTH) {
        bytes = ISC_SHA256_BLOCK_LENGTH;
        key->key_size = ISC_SHA256_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_SHA256_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacsha256_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacsha256_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacsha256_destroy(dst_key_t *key) {
    dst_hmacsha256_key_t *hkey = key->keydata.hmacsha256;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacsha256 = NULL;
}

static isc_result_t
hmacsha256_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha256_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacsha256 != NULL);

    hkey = key->keydata.hmacsha256;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha256_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha256_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_sha256_t sha256ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacsha256_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_SHA256_BLOCK_LENGTH) {
        isc_sha256_init(&sha256ctx);
        isc_sha256_update(&sha256ctx, r.base, r.length);
        isc_sha256_final(hkey->key, &sha256ctx);
        keylen = ISC_SHA256_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacsha256 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha256_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacsha256_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacsha256 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacsha256;

    priv.elements[cnt].tag = TAG_HMACSHA256_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACSHA256_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacsha256_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACSHA256, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACSHA256_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacsha256_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACSHA256_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacsha256_functions = {
    hmacsha256_createctx,
    NULL, /*%< createctx2 */
    hmacsha256_destroyctx,
    hmacsha256_adddata,
    hmacsha256_sign,
    hmacsha256_verify,
    NULL, /* verify2 */
    NULL, /* computesecret */
    hmacsha256_compare,
    NULL, /* paramcompare */
    hmacsha256_generate,
    hmacsha256_isprivate,
    hmacsha256_destroy,
    hmacsha256_todns,
    hmacsha256_fromdns,
    hmacsha256_tofile,
    hmacsha256_parse,
    NULL, /* cleanup */
    NULL, /* fromlabel */
    NULL, /* dump */
    NULL, /* restore */
};

isc_result_t
dst__hmacsha256_init(dst_func_t **funcp) {
    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacsha256_functions;
    return (ISC_R_SUCCESS);
}

static isc_result_t hmacsha384_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacsha384_key {
    unsigned char key[ISC_SHA384_BLOCK_LENGTH];
};

static isc_result_t
hmacsha384_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacsha384_t *hmacsha384ctx;
    dst_hmacsha384_key_t *hkey = key->keydata.hmacsha384;

    hmacsha384ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacsha384_t));
    if (hmacsha384ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacsha384_init(hmacsha384ctx, hkey->key, ISC_SHA384_BLOCK_LENGTH);
    dctx->ctxdata.hmacsha384ctx = hmacsha384ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacsha384_destroyctx(dst_context_t *dctx) {
    isc_hmacsha384_t *hmacsha384ctx = dctx->ctxdata.hmacsha384ctx;

    if (hmacsha384ctx != NULL) {
        isc_hmacsha384_invalidate(hmacsha384ctx);
        isc_mem_put(dctx->mctx, hmacsha384ctx, sizeof(isc_hmacsha384_t));
        dctx->ctxdata.hmacsha384ctx = NULL;
    }
}

static isc_result_t
hmacsha384_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacsha384_t *hmacsha384ctx = dctx->ctxdata.hmacsha384ctx;

    isc_hmacsha384_update(hmacsha384ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha384_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacsha384_t *hmacsha384ctx = dctx->ctxdata.hmacsha384ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_SHA384_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacsha384_sign(hmacsha384ctx, digest, ISC_SHA384_DIGESTLENGTH);
    isc_buffer_add(sig, ISC_SHA384_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha384_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacsha384_t *hmacsha384ctx = dctx->ctxdata.hmacsha384ctx;

    if (sig->length > ISC_SHA384_DIGESTLENGTH || sig->length == 0)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacsha384_verify(hmacsha384ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacsha384_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacsha384_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacsha384;
    hkey2 = key2->keydata.hmacsha384;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_SHA384_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacsha384_generate(dst_key_t *key, int pseudorandom_ok,
            void (*callback)(int))
{
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_SHA384_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_SHA384_BLOCK_LENGTH) {
        bytes = ISC_SHA384_BLOCK_LENGTH;
        key->key_size = ISC_SHA384_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_SHA384_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacsha384_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacsha384_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacsha384_destroy(dst_key_t *key) {
    dst_hmacsha384_key_t *hkey = key->keydata.hmacsha384;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacsha384 = NULL;
}

static isc_result_t
hmacsha384_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha384_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacsha384 != NULL);

    hkey = key->keydata.hmacsha384;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha384_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha384_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_sha384_t sha384ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacsha384_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_SHA384_BLOCK_LENGTH) {
        isc_sha384_init(&sha384ctx);
        isc_sha384_update(&sha384ctx, r.base, r.length);
        isc_sha384_final(hkey->key, &sha384ctx);
        keylen = ISC_SHA384_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacsha384 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha384_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacsha384_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacsha384 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacsha384;

    priv.elements[cnt].tag = TAG_HMACSHA384_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACSHA384_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacsha384_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACSHA384, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACSHA384_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacsha384_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACSHA384_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacsha384_functions = {
    hmacsha384_createctx,
    NULL, /*%< createctx2 */
    hmacsha384_destroyctx,
    hmacsha384_adddata,
    hmacsha384_sign,
    hmacsha384_verify,
    NULL, /* verify2 */
    NULL, /* computesecret */
    hmacsha384_compare,
    NULL, /* paramcompare */
    hmacsha384_generate,
    hmacsha384_isprivate,
    hmacsha384_destroy,
    hmacsha384_todns,
    hmacsha384_fromdns,
    hmacsha384_tofile,
    hmacsha384_parse,
    NULL, /* cleanup */
    NULL, /* fromlabel */
    NULL, /* dump */
    NULL, /* restore */
};

isc_result_t
dst__hmacsha384_init(dst_func_t **funcp) {
    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacsha384_functions;
    return (ISC_R_SUCCESS);
}

static isc_result_t hmacsha512_fromdns(dst_key_t *key, isc_buffer_t *data);

struct dst_hmacsha512_key {
    unsigned char key[ISC_SHA512_BLOCK_LENGTH];
};

static isc_result_t
hmacsha512_createctx(dst_key_t *key, dst_context_t *dctx) {
    isc_hmacsha512_t *hmacsha512ctx;
    dst_hmacsha512_key_t *hkey = key->keydata.hmacsha512;

    hmacsha512ctx = isc_mem_get(dctx->mctx, sizeof(isc_hmacsha512_t));
    if (hmacsha512ctx == NULL)
        return (ISC_R_NOMEMORY);
    isc_hmacsha512_init(hmacsha512ctx, hkey->key, ISC_SHA512_BLOCK_LENGTH);
    dctx->ctxdata.hmacsha512ctx = hmacsha512ctx;
    return (ISC_R_SUCCESS);
}

static void
hmacsha512_destroyctx(dst_context_t *dctx) {
    isc_hmacsha512_t *hmacsha512ctx = dctx->ctxdata.hmacsha512ctx;

    if (hmacsha512ctx != NULL) {
        isc_hmacsha512_invalidate(hmacsha512ctx);
        isc_mem_put(dctx->mctx, hmacsha512ctx, sizeof(isc_hmacsha512_t));
        dctx->ctxdata.hmacsha512ctx = NULL;
    }
}

static isc_result_t
hmacsha512_adddata(dst_context_t *dctx, const isc_region_t *data) {
    isc_hmacsha512_t *hmacsha512ctx = dctx->ctxdata.hmacsha512ctx;

    isc_hmacsha512_update(hmacsha512ctx, data->base, data->length);
    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha512_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    isc_hmacsha512_t *hmacsha512ctx = dctx->ctxdata.hmacsha512ctx;
    unsigned char *digest;

    if (isc_buffer_availablelength(sig) < ISC_SHA512_DIGESTLENGTH)
        return (ISC_R_NOSPACE);
    digest = isc_buffer_used(sig);
    isc_hmacsha512_sign(hmacsha512ctx, digest, ISC_SHA512_DIGESTLENGTH);
    isc_buffer_add(sig, ISC_SHA512_DIGESTLENGTH);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha512_verify(dst_context_t *dctx, const isc_region_t *sig) {
    isc_hmacsha512_t *hmacsha512ctx = dctx->ctxdata.hmacsha512ctx;

    if (sig->length > ISC_SHA512_DIGESTLENGTH || sig->length == 0)
        return (DST_R_VERIFYFAILURE);

    if (isc_hmacsha512_verify(hmacsha512ctx, sig->base, sig->length))
        return (ISC_R_SUCCESS);
    else
        return (DST_R_VERIFYFAILURE);
}

static isc_boolean_t
hmacsha512_compare(const dst_key_t *key1, const dst_key_t *key2) {
    dst_hmacsha512_key_t *hkey1, *hkey2;

    hkey1 = key1->keydata.hmacsha512;
    hkey2 = key2->keydata.hmacsha512;

    if (hkey1 == NULL && hkey2 == NULL)
        return (ISC_TRUE);
    else if (hkey1 == NULL || hkey2 == NULL)
        return (ISC_FALSE);

    if (isc_safe_memequal(hkey1->key, hkey2->key, ISC_SHA512_BLOCK_LENGTH))
        return (ISC_TRUE);
    else
        return (ISC_FALSE);
}

static isc_result_t
hmacsha512_generate(dst_key_t *key, int pseudorandom_ok,
            void (*callback)(int))
{
    isc_buffer_t b;
    isc_result_t ret;
    unsigned int bytes;
    unsigned char data[ISC_SHA512_BLOCK_LENGTH];

    UNUSED(callback);

    bytes = (key->key_size + 7) / 8;
    if (bytes > ISC_SHA512_BLOCK_LENGTH) {
        bytes = ISC_SHA512_BLOCK_LENGTH;
        key->key_size = ISC_SHA512_BLOCK_LENGTH * 8;
    }

    memset(data, 0, ISC_SHA512_BLOCK_LENGTH);
    ret = dst__entropy_getdata(data, bytes, ISC_TF(pseudorandom_ok != 0));

    if (ret != ISC_R_SUCCESS)
        return (ret);

    isc_buffer_init(&b, data, bytes);
    isc_buffer_add(&b, bytes);
    ret = hmacsha512_fromdns(key, &b);
    isc_safe_memwipe(data, sizeof(data));

    return (ret);
}

static isc_boolean_t
hmacsha512_isprivate(const dst_key_t *key) {
    UNUSED(key);
    return (ISC_TRUE);
}

static void
hmacsha512_destroy(dst_key_t *key) {
    dst_hmacsha512_key_t *hkey = key->keydata.hmacsha512;

    isc_safe_memwipe(hkey, sizeof(*hkey));
    isc_mem_put(key->mctx, hkey, sizeof(*hkey));
    key->keydata.hmacsha512 = NULL;
}

static isc_result_t
hmacsha512_todns(const dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha512_key_t *hkey;
    unsigned int bytes;

    REQUIRE(key->keydata.hmacsha512 != NULL);

    hkey = key->keydata.hmacsha512;

    bytes = (key->key_size + 7) / 8;
    if (isc_buffer_availablelength(data) < bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_putmem(data, hkey->key, bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha512_fromdns(dst_key_t *key, isc_buffer_t *data) {
    dst_hmacsha512_key_t *hkey;
    int keylen;
    isc_region_t r;
    isc_sha512_t sha512ctx;

    isc_buffer_remainingregion(data, &r);
    if (r.length == 0)
        return (ISC_R_SUCCESS);

    hkey = isc_mem_get(key->mctx, sizeof(dst_hmacsha512_key_t));
    if (hkey == NULL)
        return (ISC_R_NOMEMORY);

    memset(hkey->key, 0, sizeof(hkey->key));

    if (r.length > ISC_SHA512_BLOCK_LENGTH) {
        isc_sha512_init(&sha512ctx);
        isc_sha512_update(&sha512ctx, r.base, r.length);
        isc_sha512_final(hkey->key, &sha512ctx);
        keylen = ISC_SHA512_DIGESTLENGTH;
    } else {
        memmove(hkey->key, r.base, r.length);
        keylen = r.length;
    }

    key->key_size = keylen * 8;
    key->keydata.hmacsha512 = hkey;

    isc_buffer_forward(data, r.length);

    return (ISC_R_SUCCESS);
}

static isc_result_t
hmacsha512_tofile(const dst_key_t *key, const char *directory) {
    int cnt = 0;
    dst_hmacsha512_key_t *hkey;
    dst_private_t priv;
    int bytes = (key->key_size + 7) / 8;
    unsigned char buf[2];

    if (key->keydata.hmacsha512 == NULL)
        return (DST_R_NULLKEY);

    if (key->external)
        return (DST_R_EXTERNALKEY);

    hkey = key->keydata.hmacsha512;

    priv.elements[cnt].tag = TAG_HMACSHA512_KEY;
    priv.elements[cnt].length = bytes;
    priv.elements[cnt++].data = hkey->key;

    buf[0] = (key->key_bits >> 8) & 0xffU;
    buf[1] = key->key_bits & 0xffU;
    priv.elements[cnt].tag = TAG_HMACSHA512_BITS;
    priv.elements[cnt].data = buf;
    priv.elements[cnt++].length = 2;

    priv.nelements = cnt;
    return (dst__privstruct_writefile(key, &priv, directory));
}

static isc_result_t
hmacsha512_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
    dst_private_t priv;
    isc_result_t result, tresult;
    isc_buffer_t b;
    isc_mem_t *mctx = key->mctx;
    unsigned int i;

    UNUSED(pub);
    /* read private key file */
    result = dst__privstruct_parse(key, DST_ALG_HMACSHA512, lexer, mctx,
                       &priv);
    if (result != ISC_R_SUCCESS)
        return (result);

    if (key->external)
        result = DST_R_EXTERNALKEY;

    key->key_bits = 0;
    for (i = 0; i < priv.nelements && result == ISC_R_SUCCESS; i++) {
        switch (priv.elements[i].tag) {
        case TAG_HMACSHA512_KEY:
            isc_buffer_init(&b, priv.elements[i].data,
                    priv.elements[i].length);
            isc_buffer_add(&b, priv.elements[i].length);
            tresult = hmacsha512_fromdns(key, &b);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        case TAG_HMACSHA512_BITS:
            tresult = getkeybits(key, &priv.elements[i]);
            if (tresult != ISC_R_SUCCESS)
                result = tresult;
            break;
        default:
            result = DST_R_INVALIDPRIVATEKEY;
            break;
        }
    }
    dst__privstruct_free(&priv, mctx);
    isc_safe_memwipe(&priv, sizeof(priv));
    return (result);
}

static dst_func_t hmacsha512_functions = {
    hmacsha512_createctx,
    NULL, /*%< createctx2 */
    hmacsha512_destroyctx,
    hmacsha512_adddata,
    hmacsha512_sign,
    hmacsha512_verify,
    NULL, /* verify2 */
    NULL, /* computesecret */
    hmacsha512_compare,
    NULL, /* paramcompare */
    hmacsha512_generate,
    hmacsha512_isprivate,
    hmacsha512_destroy,
    hmacsha512_todns,
    hmacsha512_fromdns,
    hmacsha512_tofile,
    hmacsha512_parse,
    NULL, /* cleanup */
    NULL, /* fromlabel */
    NULL, /* dump */
    NULL, /* restore */
};

isc_result_t
dst__hmacsha512_init(dst_func_t **funcp) {
    REQUIRE(funcp != NULL);
    if (*funcp == NULL)
        *funcp = &hmacsha512_functions;
    return (ISC_R_SUCCESS);
}

/*! \file */