opensslrsa_link.c

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/*
 * Copyright (C) 2004-2009, 2011-2015  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000-2003  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 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
 * $Id$
 */
#ifdef OPENSSL
#include <config.h>

#ifndef USE_EVP
#if !defined(HAVE_EVP_SHA256) || !defined(HAVE_EVP_SHA512)
#define USE_EVP 0
#else
#define USE_EVP 1
#endif
#endif


#include <isc/entropy.h>
#include <isc/md5.h>
#include <isc/sha1.h>
#include <isc/sha2.h>
#include <isc/mem.h>
#include <isc/string.h>
#include <isc/util.h>

#include <dst/result.h>

#include "dst_internal.h"
#include "dst_openssl.h"
#include "dst_parse.h"

#include <openssl/err.h>
#include <openssl/objects.h>
#include <openssl/rsa.h>
#if OPENSSL_VERSION_NUMBER > 0x00908000L
#include <openssl/bn.h>
#endif
#ifdef USE_ENGINE
#include <openssl/engine.h>
#endif

/*
 * Limit the size of public exponents.
 */
#ifndef RSA_MAX_PUBEXP_BITS
#define RSA_MAX_PUBEXP_BITS    35
#endif

/*
 * We don't use configure for windows so enforce the OpenSSL version
 * here.  Unlike with configure we don't support overriding this test.
 */
#ifdef WIN32
#if !((OPENSSL_VERSION_NUMBER >= 0x009070cfL && \
       OPENSSL_VERSION_NUMBER < 0x00908000L) || \
      OPENSSL_VERSION_NUMBER >= 0x0090804fL)
#error Please upgrade OpenSSL to 0.9.8d/0.9.7l or greater.
#endif
#endif


        /*
         * XXXMPA  Temporarily disable RSA_BLINDING as it requires
         * good quality random data that cannot currently be guaranteed.
         * XXXMPA  Find which versions of openssl use pseudo random data
         * and set RSA_FLAG_BLINDING for those.
         */

#if 0
#if OPENSSL_VERSION_NUMBER < 0x0090601fL
#define SET_FLAGS(rsa) \
        do { \
        (rsa)->flags &= ~(RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE); \
        (rsa)->flags |= RSA_FLAG_BLINDING; \
        } while (0)
#else
#define SET_FLAGS(rsa) \
        do { \
                (rsa)->flags |= RSA_FLAG_BLINDING; \
        } while (0)
#endif
#endif

#if OPENSSL_VERSION_NUMBER < 0x0090601fL
#define SET_FLAGS(rsa) \
        do { \
        (rsa)->flags &= ~(RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE); \
        (rsa)->flags &= ~RSA_FLAG_BLINDING; \
        } while (0)
#elif defined(RSA_FLAG_NO_BLINDING)
#define SET_FLAGS(rsa) \
        do { \
                (rsa)->flags &= ~RSA_FLAG_BLINDING; \
                (rsa)->flags |= RSA_FLAG_NO_BLINDING; \
        } while (0)
#else
#define SET_FLAGS(rsa) \
        do { \
                (rsa)->flags &= ~RSA_FLAG_BLINDING; \
        } while (0)
#endif

#define DST_RET(a) {ret = a; goto err;}

static isc_result_t opensslrsa_todns(const dst_key_t *key, isc_buffer_t *data);

static isc_result_t
opensslrsa_createctx(dst_key_t *key, dst_context_t *dctx) {
#if USE_EVP
        EVP_MD_CTX *evp_md_ctx;
        const EVP_MD *type = NULL;
#endif

        UNUSED(key);
        REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
                dctx->key->key_alg == DST_ALG_RSASHA1 ||
                dctx->key->key_alg == DST_ALG_NSEC3RSASHA1 ||
                dctx->key->key_alg == DST_ALG_RSASHA256 ||
                dctx->key->key_alg == DST_ALG_RSASHA512);

#if USE_EVP
        evp_md_ctx = EVP_MD_CTX_create();
        if (evp_md_ctx == NULL)
                return (ISC_R_NOMEMORY);

        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                type = EVP_md5();       /* MD5 + RSA */
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                type = EVP_sha1();      /* SHA1 + RSA */
                break;
#ifdef HAVE_EVP_SHA256
        case DST_ALG_RSASHA256:
                type = EVP_sha256();    /* SHA256 + RSA */
                break;
#endif
#ifdef HAVE_EVP_SHA512
        case DST_ALG_RSASHA512:
                type = EVP_sha512();
                break;
#endif
        default:
                INSIST(0);
        }

        if (!EVP_DigestInit_ex(evp_md_ctx, type, NULL)) {
                EVP_MD_CTX_destroy(evp_md_ctx);
                return (dst__openssl_toresult3(dctx->category,
                                               "EVP_DigestInit_ex",
                                               ISC_R_FAILURE));
        }
        dctx->ctxdata.evp_md_ctx = evp_md_ctx;
#else
        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                {
                        isc_md5_t *md5ctx;

                        md5ctx = isc_mem_get(dctx->mctx, sizeof(isc_md5_t));
                        if (md5ctx == NULL)
                                return (ISC_R_NOMEMORY);
                        isc_md5_init(md5ctx);
                        dctx->ctxdata.md5ctx = md5ctx;
                }
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                {
                        isc_sha1_t *sha1ctx;

                        sha1ctx = isc_mem_get(dctx->mctx, sizeof(isc_sha1_t));
                        if (sha1ctx == NULL)
                                return (ISC_R_NOMEMORY);
                        isc_sha1_init(sha1ctx);
                        dctx->ctxdata.sha1ctx = sha1ctx;
                }
                break;
        case DST_ALG_RSASHA256:
                {
                        isc_sha256_t *sha256ctx;

                        sha256ctx = isc_mem_get(dctx->mctx,
                                                sizeof(isc_sha256_t));
                        if (sha256ctx == NULL)
                                return (ISC_R_NOMEMORY);
                        isc_sha256_init(sha256ctx);
                        dctx->ctxdata.sha256ctx = sha256ctx;
                }
                break;
        case DST_ALG_RSASHA512:
                {
                        isc_sha512_t *sha512ctx;

                        sha512ctx = isc_mem_get(dctx->mctx,
                                                sizeof(isc_sha512_t));
                        if (sha512ctx == NULL)
                                return (ISC_R_NOMEMORY);
                        isc_sha512_init(sha512ctx);
                        dctx->ctxdata.sha512ctx = sha512ctx;
                }
                break;
        default:
                INSIST(0);
        }
#endif

        return (ISC_R_SUCCESS);
}

static void
opensslrsa_destroyctx(dst_context_t *dctx) {
#if USE_EVP
        EVP_MD_CTX *evp_md_ctx = dctx->ctxdata.evp_md_ctx;
#endif

        REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
                dctx->key->key_alg == DST_ALG_RSASHA1 ||
                dctx->key->key_alg == DST_ALG_NSEC3RSASHA1 ||
                dctx->key->key_alg == DST_ALG_RSASHA256 ||
                dctx->key->key_alg == DST_ALG_RSASHA512);

#if USE_EVP
        if (evp_md_ctx != NULL) {
                EVP_MD_CTX_destroy(evp_md_ctx);
                dctx->ctxdata.evp_md_ctx = NULL;
        }
#else
        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                {
                        isc_md5_t *md5ctx = dctx->ctxdata.md5ctx;

                        if (md5ctx != NULL) {
                                isc_md5_invalidate(md5ctx);
                                isc_mem_put(dctx->mctx, md5ctx,
                                            sizeof(isc_md5_t));
                                dctx->ctxdata.md5ctx = NULL;
                        }
                }
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                {
                        isc_sha1_t *sha1ctx = dctx->ctxdata.sha1ctx;

                        if (sha1ctx != NULL) {
                                isc_sha1_invalidate(sha1ctx);
                                isc_mem_put(dctx->mctx, sha1ctx,
                                            sizeof(isc_sha1_t));
                                dctx->ctxdata.sha1ctx = NULL;
                        }
                }
                break;
        case DST_ALG_RSASHA256:
                {
                        isc_sha256_t *sha256ctx = dctx->ctxdata.sha256ctx;

                        if (sha256ctx != NULL) {
                                isc_sha256_invalidate(sha256ctx);
                                isc_mem_put(dctx->mctx, sha256ctx,
                                            sizeof(isc_sha256_t));
                                dctx->ctxdata.sha256ctx = NULL;
                        }
                }
                break;
        case DST_ALG_RSASHA512:
                {
                        isc_sha512_t *sha512ctx = dctx->ctxdata.sha512ctx;

                        if (sha512ctx != NULL) {
                                isc_sha512_invalidate(sha512ctx);
                                isc_mem_put(dctx->mctx, sha512ctx,
                                            sizeof(isc_sha512_t));
                                dctx->ctxdata.sha512ctx = NULL;
                        }
                }
                break;
        default:
                INSIST(0);
        }
#endif
}

static isc_result_t
opensslrsa_adddata(dst_context_t *dctx, const isc_region_t *data) {
#if USE_EVP
        EVP_MD_CTX *evp_md_ctx = dctx->ctxdata.evp_md_ctx;
#endif

        REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
                dctx->key->key_alg == DST_ALG_RSASHA1 ||
                dctx->key->key_alg == DST_ALG_NSEC3RSASHA1 ||
                dctx->key->key_alg == DST_ALG_RSASHA256 ||
                dctx->key->key_alg == DST_ALG_RSASHA512);

#if USE_EVP
        if (!EVP_DigestUpdate(evp_md_ctx, data->base, data->length)) {
                return (dst__openssl_toresult3(dctx->category,
                                               "EVP_DigestUpdate",
                                               ISC_R_FAILURE));
        }
#else
        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                {
                        isc_md5_t *md5ctx = dctx->ctxdata.md5ctx;

                        isc_md5_update(md5ctx, data->base, data->length);
                }
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                {
                        isc_sha1_t *sha1ctx = dctx->ctxdata.sha1ctx;

                        isc_sha1_update(sha1ctx, data->base, data->length);
                }
                break;
        case DST_ALG_RSASHA256:
                {
                        isc_sha256_t *sha256ctx = dctx->ctxdata.sha256ctx;

                        isc_sha256_update(sha256ctx, data->base, data->length);
                }
                break;
        case DST_ALG_RSASHA512:
                {
                        isc_sha512_t *sha512ctx = dctx->ctxdata.sha512ctx;

                        isc_sha512_update(sha512ctx, data->base, data->length);
                }
                break;
        default:
                INSIST(0);
        }
#endif
        return (ISC_R_SUCCESS);
}

#if ! USE_EVP && OPENSSL_VERSION_NUMBER < 0x00908000L
/*
 * Digest prefixes from RFC 5702.
 */
static unsigned char sha256_prefix[] =
         { 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48,
           0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20};
static unsigned char sha512_prefix[] =
         { 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48,
           0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40};
#define PREFIXLEN sizeof(sha512_prefix)
#else
#define PREFIXLEN 0
#endif

static isc_result_t
opensslrsa_sign(dst_context_t *dctx, isc_buffer_t *sig) {
        dst_key_t *key = dctx->key;
        isc_region_t r;
        unsigned int siglen = 0;
#if USE_EVP
        EVP_MD_CTX *evp_md_ctx = dctx->ctxdata.evp_md_ctx;
        EVP_PKEY *pkey = key->keydata.pkey;
#else
        RSA *rsa = key->keydata.rsa;
        /* note: ISC_SHA512_DIGESTLENGTH >= ISC_*_DIGESTLENGTH */
        unsigned char digest[PREFIXLEN + ISC_SHA512_DIGESTLENGTH];
        int status;
        int type = 0;
        unsigned int digestlen = 0;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
        unsigned int prefixlen = 0;
        const unsigned char *prefix = NULL;
#endif
#endif

        REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
                dctx->key->key_alg == DST_ALG_RSASHA1 ||
                dctx->key->key_alg == DST_ALG_NSEC3RSASHA1 ||
                dctx->key->key_alg == DST_ALG_RSASHA256 ||
                dctx->key->key_alg == DST_ALG_RSASHA512);

        isc_buffer_availableregion(sig, &r);

#if USE_EVP
        if (r.length < (unsigned int) EVP_PKEY_size(pkey))
                return (ISC_R_NOSPACE);

        if (!EVP_SignFinal(evp_md_ctx, r.base, &siglen, pkey)) {
                return (dst__openssl_toresult3(dctx->category,
                                               "EVP_SignFinal",
                                               ISC_R_FAILURE));
        }
#else
        if (r.length < (unsigned int) RSA_size(rsa))
                return (ISC_R_NOSPACE);

        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                {
                        isc_md5_t *md5ctx = dctx->ctxdata.md5ctx;

                        isc_md5_final(md5ctx, digest);
                        type = NID_md5;
                        digestlen = ISC_MD5_DIGESTLENGTH;
                }
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                {
                        isc_sha1_t *sha1ctx = dctx->ctxdata.sha1ctx;

                        isc_sha1_final(sha1ctx, digest);
                        type = NID_sha1;
                        digestlen = ISC_SHA1_DIGESTLENGTH;
                }
                break;
        case DST_ALG_RSASHA256:
                {
                        isc_sha256_t *sha256ctx = dctx->ctxdata.sha256ctx;

                        isc_sha256_final(digest, sha256ctx);
                        digestlen = ISC_SHA256_DIGESTLENGTH;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
                        prefix = sha256_prefix;
                        prefixlen = sizeof(sha256_prefix);
#else
                        type = NID_sha256;
#endif
                }
                break;
        case DST_ALG_RSASHA512:
                {
                        isc_sha512_t *sha512ctx = dctx->ctxdata.sha512ctx;

                        isc_sha512_final(digest, sha512ctx);
                        digestlen = ISC_SHA512_DIGESTLENGTH;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
                        prefix = sha512_prefix;
                        prefixlen = sizeof(sha512_prefix);
#else
                        type = NID_sha512;
#endif
                }
                break;
        default:
                INSIST(0);
        }

#if OPENSSL_VERSION_NUMBER < 0x00908000L
        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                INSIST(type != 0);
                status = RSA_sign(type, digest, digestlen, r.base,
                                  &siglen, rsa);
                break;

        case DST_ALG_RSASHA256:
        case DST_ALG_RSASHA512:
                INSIST(prefix != NULL);
                INSIST(prefixlen != 0);
                INSIST(prefixlen + digestlen <= sizeof(digest));

                memmove(digest + prefixlen, digest, digestlen);
                memmove(digest, prefix, prefixlen);
                status = RSA_private_encrypt(digestlen + prefixlen,
                                             digest, r.base, rsa,
                                             RSA_PKCS1_PADDING);
                if (status < 0)
                        status = 0;
                else
                        siglen = status;
                break;

        default:
                INSIST(0);
        }
#else
        INSIST(type != 0);
        status = RSA_sign(type, digest, digestlen, r.base, &siglen, rsa);
#endif
        if (status == 0)
                return (dst__openssl_toresult3(dctx->category,
                                               "RSA_sign",
                                               DST_R_OPENSSLFAILURE));
#endif

        isc_buffer_add(sig, siglen);

        return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_verify2(dst_context_t *dctx, int maxbits, const isc_region_t *sig) {
        dst_key_t *key = dctx->key;
        int status = 0;
#if USE_EVP
        EVP_MD_CTX *evp_md_ctx = dctx->ctxdata.evp_md_ctx;
        EVP_PKEY *pkey = key->keydata.pkey;
        RSA *rsa;
        int bits;
#else
        /* note: ISC_SHA512_DIGESTLENGTH >= ISC_*_DIGESTLENGTH */
        unsigned char digest[ISC_SHA512_DIGESTLENGTH];
        int type = 0;
        unsigned int digestlen = 0;
        RSA *rsa = key->keydata.rsa;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
        unsigned int prefixlen = 0;
        const unsigned char *prefix = NULL;
#endif
#endif

        REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
                dctx->key->key_alg == DST_ALG_RSASHA1 ||
                dctx->key->key_alg == DST_ALG_NSEC3RSASHA1 ||
                dctx->key->key_alg == DST_ALG_RSASHA256 ||
                dctx->key->key_alg == DST_ALG_RSASHA512);

#if USE_EVP
        rsa = EVP_PKEY_get1_RSA(pkey);
        if (rsa == NULL)
                return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
        bits = BN_num_bits(rsa->e);
        RSA_free(rsa);
        if (bits > maxbits && maxbits != 0)
                return (DST_R_VERIFYFAILURE);

        status = EVP_VerifyFinal(evp_md_ctx, sig->base, sig->length, pkey);
        switch (status) {
        case 1:
                return (ISC_R_SUCCESS);
        case 0:
                return (dst__openssl_toresult(DST_R_VERIFYFAILURE));
        default:
                return (dst__openssl_toresult3(dctx->category,
                                               "EVP_VerifyFinal",
                                               DST_R_VERIFYFAILURE));
        }
#else
        if (BN_num_bits(rsa->e) > maxbits && maxbits != 0)
                return (DST_R_VERIFYFAILURE);

        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
                {
                        isc_md5_t *md5ctx = dctx->ctxdata.md5ctx;

                        isc_md5_final(md5ctx, digest);
                        type = NID_md5;
                        digestlen = ISC_MD5_DIGESTLENGTH;
                }
                break;
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                {
                        isc_sha1_t *sha1ctx = dctx->ctxdata.sha1ctx;

                        isc_sha1_final(sha1ctx, digest);
                        type = NID_sha1;
                        digestlen = ISC_SHA1_DIGESTLENGTH;
                }
                break;
        case DST_ALG_RSASHA256:
                {
                        isc_sha256_t *sha256ctx = dctx->ctxdata.sha256ctx;

                        isc_sha256_final(digest, sha256ctx);
                        digestlen = ISC_SHA256_DIGESTLENGTH;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
                        prefix = sha256_prefix;
                        prefixlen = sizeof(sha256_prefix);
#else
                        type = NID_sha256;
#endif
                }
                break;
        case DST_ALG_RSASHA512:
                {
                        isc_sha512_t *sha512ctx = dctx->ctxdata.sha512ctx;

                        isc_sha512_final(digest, sha512ctx);
                        digestlen = ISC_SHA512_DIGESTLENGTH;
#if OPENSSL_VERSION_NUMBER < 0x00908000L
                        prefix = sha512_prefix;
                        prefixlen = sizeof(sha512_prefix);
#else
                        type = NID_sha512;
#endif
                }
                break;
        default:
                INSIST(0);
        }

        if (sig->length != (unsigned int) RSA_size(rsa))
                return (DST_R_VERIFYFAILURE);

#if OPENSSL_VERSION_NUMBER < 0x00908000L
        switch (dctx->key->key_alg) {
        case DST_ALG_RSAMD5:
        case DST_ALG_RSASHA1:
        case DST_ALG_NSEC3RSASHA1:
                INSIST(type != 0);
                status = RSA_verify(type, digest, digestlen, sig->base,
                                    RSA_size(rsa), rsa);
                break;

        case DST_ALG_RSASHA256:
        case DST_ALG_RSASHA512:
                {
                        /*
                         * 1024 is big enough for all valid RSA bit sizes
                         * for use with DNSSEC.
                         */
                        unsigned char original[PREFIXLEN + 1024];

                        INSIST(prefix != NULL);
                        INSIST(prefixlen != 0U);

                        if (RSA_size(rsa) > (int)sizeof(original))
                                return (DST_R_VERIFYFAILURE);

                        status = RSA_public_decrypt(sig->length, sig->base,
                                                    original, rsa,
                                                    RSA_PKCS1_PADDING);
                        if (status <= 0)
                                return (dst__openssl_toresult3(
                                                dctx->category,
                                                "RSA_public_decrypt",
                                                DST_R_VERIFYFAILURE));
                        if (status != (int)(prefixlen + digestlen))
                                return (DST_R_VERIFYFAILURE);
                        if (memcmp(original, prefix, prefixlen))
                                return (DST_R_VERIFYFAILURE);
                        if (memcmp(original + prefixlen, digest, digestlen))
                                return (DST_R_VERIFYFAILURE);
                        status = 1;
                }
                break;

        default:
                INSIST(0);
        }
#else
        INSIST(type != 0);
        status = RSA_verify(type, digest, digestlen, sig->base,
                             RSA_size(rsa), rsa);
#endif
        if (status != 1)
                return (dst__openssl_toresult(DST_R_VERIFYFAILURE));
        return (ISC_R_SUCCESS);
#endif
}

static isc_result_t
opensslrsa_verify(dst_context_t *dctx, const isc_region_t *sig) {
        return (opensslrsa_verify2(dctx, 0, sig));
}

static isc_boolean_t
opensslrsa_compare(const dst_key_t *key1, const dst_key_t *key2) {
        int status;
        RSA *rsa1 = NULL, *rsa2 = NULL;
#if USE_EVP
        EVP_PKEY *pkey1, *pkey2;
#endif

#if USE_EVP
        pkey1 = key1->keydata.pkey;
        pkey2 = key2->keydata.pkey;
        /*
         * The pkey reference will keep these around after
         * the RSA_free() call.
         */
        if (pkey1 != NULL) {
                rsa1 = EVP_PKEY_get1_RSA(pkey1);
                RSA_free(rsa1);
        }
        if (pkey2 != NULL) {
                rsa2 = EVP_PKEY_get1_RSA(pkey2);
                RSA_free(rsa2);
        }
#else
        rsa1 = key1->keydata.rsa;
        rsa2 = key2->keydata.rsa;
#endif

        if (rsa1 == NULL && rsa2 == NULL)
                return (ISC_TRUE);
        else if (rsa1 == NULL || rsa2 == NULL)
                return (ISC_FALSE);

        status = BN_cmp(rsa1->n, rsa2->n) ||
                 BN_cmp(rsa1->e, rsa2->e);

        if (status != 0)
                return (ISC_FALSE);

#if USE_EVP
        if ((rsa1->flags & RSA_FLAG_EXT_PKEY) != 0 ||
            (rsa2->flags & RSA_FLAG_EXT_PKEY) != 0) {
                if ((rsa1->flags & RSA_FLAG_EXT_PKEY) == 0 ||
                    (rsa2->flags & RSA_FLAG_EXT_PKEY) == 0)
                        return (ISC_FALSE);
                /*
                 * Can't compare private parameters, BTW does it make sense?
                 */
                return (ISC_TRUE);
        }
#endif

        if (rsa1->d != NULL || rsa2->d != NULL) {
                if (rsa1->d == NULL || rsa2->d == NULL)
                        return (ISC_FALSE);
                status = BN_cmp(rsa1->d, rsa2->d) ||
                         BN_cmp(rsa1->p, rsa2->p) ||
                         BN_cmp(rsa1->q, rsa2->q);

                if (status != 0)
                        return (ISC_FALSE);
        }
        return (ISC_TRUE);
}

#if OPENSSL_VERSION_NUMBER > 0x00908000L
static int
progress_cb(int p, int n, BN_GENCB *cb) {
        union {
                void *dptr;
                void (*fptr)(int);
        } u;

        UNUSED(n);

        u.dptr = cb->arg;
        if (u.fptr != NULL)
                u.fptr(p);
        return (1);
}
#endif

static isc_result_t
opensslrsa_generate(dst_key_t *key, int exp, void (*callback)(int)) {
#if OPENSSL_VERSION_NUMBER > 0x00908000L
        isc_result_t ret = DST_R_OPENSSLFAILURE;
        BN_GENCB cb;
        union {
                void *dptr;
                void (*fptr)(int);
        } u;
        RSA *rsa = RSA_new();
        BIGNUM *e = BN_new();
#if USE_EVP
        EVP_PKEY *pkey = EVP_PKEY_new();
#endif

        if (rsa == NULL || e == NULL)
                goto err;
#if USE_EVP
        if (pkey == NULL)
                goto err;
        if (!EVP_PKEY_set1_RSA(pkey, rsa))
                goto err;
#endif

        if (exp == 0) {
                /* RSA_F4 0x10001 */
                BN_set_bit(e, 0);
                BN_set_bit(e, 16);
        } else {
                /* (phased-out) F5 0x100000001 */
                BN_set_bit(e, 0);
                BN_set_bit(e, 32);
        }

        if (callback == NULL) {
                BN_GENCB_set_old(&cb, NULL, NULL);
        } else {
                u.fptr = callback;
                BN_GENCB_set(&cb, &progress_cb, u.dptr);
        }

        if (RSA_generate_key_ex(rsa, key->key_size, e, &cb)) {
                BN_free(e);
                SET_FLAGS(rsa);
#if USE_EVP
                key->keydata.pkey = pkey;

                RSA_free(rsa);
#else
                key->keydata.rsa = rsa;
#endif
                return (ISC_R_SUCCESS);
        }
        ret = dst__openssl_toresult2("RSA_generate_key_ex",
                                     DST_R_OPENSSLFAILURE);

err:
#if USE_EVP
        if (pkey != NULL)
                EVP_PKEY_free(pkey);
#endif
        if (e != NULL)
                BN_free(e);
        if (rsa != NULL)
                RSA_free(rsa);
        return (dst__openssl_toresult(ret));
#else
        RSA *rsa;
        unsigned long e;
#if USE_EVP
        EVP_PKEY *pkey = EVP_PKEY_new();

        UNUSED(callback);

        if (pkey == NULL)
                return (ISC_R_NOMEMORY);
#else
        UNUSED(callback);
#endif

        if (exp == 0)
               e = RSA_F4;
        else
               e = 0x40000003;
        rsa = RSA_generate_key(key->key_size, e, NULL, NULL);
        if (rsa == NULL) {
#if USE_EVP
                EVP_PKEY_free(pkey);
#endif
                return (dst__openssl_toresult2("RSA_generate_key",
                                               DST_R_OPENSSLFAILURE));
        }
        SET_FLAGS(rsa);
#if USE_EVP
        if (!EVP_PKEY_set1_RSA(pkey, rsa)) {
                EVP_PKEY_free(pkey);
                RSA_free(rsa);
                return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
        }
        key->keydata.pkey = pkey;
        RSA_free(rsa);
#else
        key->keydata.rsa = rsa;
#endif

        return (ISC_R_SUCCESS);
#endif
}

static isc_boolean_t
opensslrsa_isprivate(const dst_key_t *key) {
#if USE_EVP
        RSA *rsa = EVP_PKEY_get1_RSA(key->keydata.pkey);
        INSIST(rsa != NULL);
        RSA_free(rsa);
        /* key->keydata.pkey still has a reference so rsa is still valid. */
#else
        RSA *rsa = key->keydata.rsa;
#endif
        if (rsa != NULL && (rsa->flags & RSA_FLAG_EXT_PKEY) != 0)
                return (ISC_TRUE);
        return (ISC_TF(rsa != NULL && rsa->d != NULL));
}

static void
opensslrsa_destroy(dst_key_t *key) {
#if USE_EVP
        EVP_PKEY *pkey = key->keydata.pkey;
        EVP_PKEY_free(pkey);
        key->keydata.pkey = NULL;
#else
        RSA *rsa = key->keydata.rsa;
        RSA_free(rsa);
        key->keydata.rsa = NULL;
#endif
}


static isc_result_t
opensslrsa_todns(const dst_key_t *key, isc_buffer_t *data) {
        isc_region_t r;
        unsigned int e_bytes;
        unsigned int mod_bytes;
        isc_result_t ret;
        RSA *rsa;
#if USE_EVP
        EVP_PKEY *pkey;
#endif

#if USE_EVP
        REQUIRE(key->keydata.pkey != NULL);
#else
        REQUIRE(key->keydata.rsa != NULL);
#endif

#if USE_EVP
        pkey = key->keydata.pkey;
        rsa = EVP_PKEY_get1_RSA(pkey);
        if (rsa == NULL)
                return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
#else
        rsa = key->keydata.rsa;
#endif

        isc_buffer_availableregion(data, &r);

        e_bytes = BN_num_bytes(rsa->e);
        mod_bytes = BN_num_bytes(rsa->n);

        if (e_bytes < 256) {    /*%< key exponent is <= 2040 bits */
                if (r.length < 1)
                        DST_RET(ISC_R_NOSPACE);
                isc_buffer_putuint8(data, (isc_uint8_t) e_bytes);
                isc_region_consume(&r, 1);
        } else {
                if (r.length < 3)
                        DST_RET(ISC_R_NOSPACE);
                isc_buffer_putuint8(data, 0);
                isc_buffer_putuint16(data, (isc_uint16_t) e_bytes);
                isc_region_consume(&r, 3);
        }

        if (r.length < e_bytes + mod_bytes)
                DST_RET(ISC_R_NOSPACE);

        BN_bn2bin(rsa->e, r.base);
        isc_region_consume(&r, e_bytes);
        BN_bn2bin(rsa->n, r.base);

        isc_buffer_add(data, e_bytes + mod_bytes);

        ret = ISC_R_SUCCESS;
 err:
#if USE_EVP
        if (rsa != NULL)
                RSA_free(rsa);
#endif
        return (ret);
}

static isc_result_t
opensslrsa_fromdns(dst_key_t *key, isc_buffer_t *data) {
        RSA *rsa;
        isc_region_t r;
        unsigned int e_bytes;
#if USE_EVP
        EVP_PKEY *pkey;
#endif

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

        rsa = RSA_new();
        if (rsa == NULL)
                return (dst__openssl_toresult(ISC_R_NOMEMORY));
        SET_FLAGS(rsa);

        if (r.length < 1) {
                RSA_free(rsa);
                return (DST_R_INVALIDPUBLICKEY);
        }
        e_bytes = *r.base++;
        r.length--;

        if (e_bytes == 0) {
                if (r.length < 2) {
                        RSA_free(rsa);
                        return (DST_R_INVALIDPUBLICKEY);
                }
                e_bytes = ((*r.base++) << 8);
                e_bytes += *r.base++;
                r.length -= 2;
        }

        if (r.length < e_bytes) {
                RSA_free(rsa);
                return (DST_R_INVALIDPUBLICKEY);
        }
        rsa->e = BN_bin2bn(r.base, e_bytes, NULL);
        r.base += e_bytes;
        r.length -= e_bytes;

        rsa->n = BN_bin2bn(r.base, r.length, NULL);

        key->key_size = BN_num_bits(rsa->n);

        isc_buffer_forward(data, r.length);

#if USE_EVP
        pkey = EVP_PKEY_new();
        if (pkey == NULL) {
                RSA_free(rsa);
                return (ISC_R_NOMEMORY);
        }
        if (!EVP_PKEY_set1_RSA(pkey, rsa)) {
                EVP_PKEY_free(pkey);
                RSA_free(rsa);
                return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
        }
        key->keydata.pkey = pkey;
        RSA_free(rsa);
#else
        key->keydata.rsa = rsa;
#endif

        return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_tofile(const dst_key_t *key, const char *directory) {
        int i;
        RSA *rsa;
        dst_private_t priv;
        unsigned char *bufs[8];
        isc_result_t result;

#if USE_EVP
        if (key->keydata.pkey == NULL)
                return (DST_R_NULLKEY);
        rsa = EVP_PKEY_get1_RSA(key->keydata.pkey);
        if (rsa == NULL)
                return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
#else
        if (key->keydata.rsa == NULL)
                return (DST_R_NULLKEY);
        rsa = key->keydata.rsa;
#endif
        memset(bufs, 0, sizeof(bufs));

        if (key->external) {
                priv.nelements = 0;
                result = dst__privstruct_writefile(key, &priv, directory);
                goto fail;
        }

        for (i = 0; i < 8; i++) {
                bufs[i] = isc_mem_get(key->mctx, BN_num_bytes(rsa->n));
                if (bufs[i] == NULL) {
                        result = ISC_R_NOMEMORY;
                        goto fail;
                }
        }

        i = 0;

        priv.elements[i].tag = TAG_RSA_MODULUS;
        priv.elements[i].length = BN_num_bytes(rsa->n);
        BN_bn2bin(rsa->n, bufs[i]);
        priv.elements[i].data = bufs[i];
        i++;

        priv.elements[i].tag = TAG_RSA_PUBLICEXPONENT;
        priv.elements[i].length = BN_num_bytes(rsa->e);
        BN_bn2bin(rsa->e, bufs[i]);
        priv.elements[i].data = bufs[i];
        i++;

        if (rsa->d != NULL) {
                priv.elements[i].tag = TAG_RSA_PRIVATEEXPONENT;
                priv.elements[i].length = BN_num_bytes(rsa->d);
                BN_bn2bin(rsa->d, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (rsa->p != NULL) {
                priv.elements[i].tag = TAG_RSA_PRIME1;
                priv.elements[i].length = BN_num_bytes(rsa->p);
                BN_bn2bin(rsa->p, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (rsa->q != NULL) {
                priv.elements[i].tag = TAG_RSA_PRIME2;
                priv.elements[i].length = BN_num_bytes(rsa->q);
                BN_bn2bin(rsa->q, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (rsa->dmp1 != NULL) {
                priv.elements[i].tag = TAG_RSA_EXPONENT1;
                priv.elements[i].length = BN_num_bytes(rsa->dmp1);
                BN_bn2bin(rsa->dmp1, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (rsa->dmq1 != NULL) {
                priv.elements[i].tag = TAG_RSA_EXPONENT2;
                priv.elements[i].length = BN_num_bytes(rsa->dmq1);
                BN_bn2bin(rsa->dmq1, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (rsa->iqmp != NULL) {
                priv.elements[i].tag = TAG_RSA_COEFFICIENT;
                priv.elements[i].length = BN_num_bytes(rsa->iqmp);
                BN_bn2bin(rsa->iqmp, bufs[i]);
                priv.elements[i].data = bufs[i];
                i++;
        }

        if (key->engine != NULL) {
                priv.elements[i].tag = TAG_RSA_ENGINE;
                priv.elements[i].length =
                        (unsigned short)strlen(key->engine) + 1;
                priv.elements[i].data = (unsigned char *)key->engine;
                i++;
        }

        if (key->label != NULL) {
                priv.elements[i].tag = TAG_RSA_LABEL;
                priv.elements[i].length =
                        (unsigned short)strlen(key->label) + 1;
                priv.elements[i].data = (unsigned char *)key->label;
                i++;
        }


        priv.nelements = i;
        result = dst__privstruct_writefile(key, &priv, directory);
 fail:
#if USE_EVP
        RSA_free(rsa);
#endif
        for (i = 0; i < 8; i++) {
                if (bufs[i] == NULL)
                        break;
                isc_mem_put(key->mctx, bufs[i], BN_num_bytes(rsa->n));
        }
        return (result);
}

static isc_result_t
rsa_check(RSA *rsa, RSA *pub)
{
        /* Public parameters should be the same but if they are not set
         * copy them from the public key. */
        if (pub != NULL) {
                if (rsa->n != NULL) {
                        if (BN_cmp(rsa->n, pub->n) != 0)
                                return (DST_R_INVALIDPRIVATEKEY);
                } else {
                        rsa->n = pub->n;
                        pub->n = NULL;
                }
                if (rsa->e != NULL) {
                        if (BN_cmp(rsa->e, pub->e) != 0)
                                return (DST_R_INVALIDPRIVATEKEY);
                } else {
                        rsa->e = pub->e;
                        pub->e = NULL;
                }
        }
        if (rsa->n == NULL || rsa->e == NULL)
                return (DST_R_INVALIDPRIVATEKEY);
        return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
        dst_private_t priv;
        isc_result_t ret;
        int i;
        RSA *rsa = NULL, *pubrsa = NULL;
#ifdef USE_ENGINE
        ENGINE *e = NULL;
#endif
        isc_mem_t *mctx = key->mctx;
        const char *engine = NULL, *label = NULL;
#if defined(USE_ENGINE) || USE_EVP
        EVP_PKEY *pkey = NULL;
#endif

        /* read private key file */
        ret = dst__privstruct_parse(key, DST_ALG_RSA, lexer, mctx, &priv);
        if (ret != ISC_R_SUCCESS)
                goto err;

        if (key->external) {
                if (priv.nelements != 0)
                        DST_RET(DST_R_INVALIDPRIVATEKEY);
                if (pub == NULL)
                        DST_RET(DST_R_INVALIDPRIVATEKEY);
                key->keydata.pkey = pub->keydata.pkey;
                pub->keydata.pkey = NULL;
                key->key_size = pub->key_size;
                dst__privstruct_free(&priv, mctx);
                memset(&priv, 0, sizeof(priv));
                return (ISC_R_SUCCESS);
        }

#if USE_EVP
        if (pub != NULL && pub->keydata.pkey != NULL)
                pubrsa = EVP_PKEY_get1_RSA(pub->keydata.pkey);
#else
        if (pub != NULL && pub->keydata.rsa != NULL) {
                pubrsa = pub->keydata.rsa;
                pub->keydata.rsa = NULL;
        }
#endif

        for (i = 0; i < priv.nelements; i++) {
                switch (priv.elements[i].tag) {
                case TAG_RSA_ENGINE:
                        engine = (char *)priv.elements[i].data;
                        break;
                case TAG_RSA_LABEL:
                        label = (char *)priv.elements[i].data;
                        break;
                default:
                        break;
                }
        }

        /*
         * Is this key is stored in a HSM?
         * See if we can fetch it.
         */
        if (label != NULL) {
#ifdef USE_ENGINE
                if (engine == NULL)
                        DST_RET(DST_R_NOENGINE);
                e = dst__openssl_getengine(engine);
                if (e == NULL)
                        DST_RET(DST_R_NOENGINE);
                pkey = ENGINE_load_private_key(e, label, NULL, NULL);
                if (pkey == NULL)
                        DST_RET(dst__openssl_toresult2(
                                        "ENGINE_load_private_key",
                                        ISC_R_NOTFOUND));
                key->engine = isc_mem_strdup(key->mctx, engine);
                if (key->engine == NULL)
                        DST_RET(ISC_R_NOMEMORY);
                key->label = isc_mem_strdup(key->mctx, label);
                if (key->label == NULL)
                        DST_RET(ISC_R_NOMEMORY);
                rsa = EVP_PKEY_get1_RSA(pkey);
                if (rsa == NULL)
                        DST_RET(dst__openssl_toresult(DST_R_OPENSSLFAILURE));
                if (rsa_check(rsa, pubrsa) != ISC_R_SUCCESS)
                        DST_RET(DST_R_INVALIDPRIVATEKEY);
                if (BN_num_bits(rsa->e) > RSA_MAX_PUBEXP_BITS)
                        DST_RET(ISC_R_RANGE);
                if (pubrsa != NULL)
                        RSA_free(pubrsa);
                key->key_size = EVP_PKEY_bits(pkey);
#if USE_EVP
                key->keydata.pkey = pkey;
                RSA_free(rsa);
#else
                key->keydata.rsa = rsa;
                EVP_PKEY_free(pkey);
#endif
                dst__privstruct_free(&priv, mctx);
                memset(&priv, 0, sizeof(priv));
                return (ISC_R_SUCCESS);
#else
                DST_RET(DST_R_NOENGINE);
#endif
        }

        rsa = RSA_new();
        if (rsa == NULL)
                DST_RET(ISC_R_NOMEMORY);
        SET_FLAGS(rsa);

#if USE_EVP
        pkey = EVP_PKEY_new();
        if (pkey == NULL)
                DST_RET(ISC_R_NOMEMORY);
        if (!EVP_PKEY_set1_RSA(pkey, rsa))
                DST_RET(ISC_R_FAILURE);
        key->keydata.pkey = pkey;
#else
        key->keydata.rsa = rsa;
#endif

        for (i = 0; i < priv.nelements; i++) {
                BIGNUM *bn;
                switch (priv.elements[i].tag) {
                case TAG_RSA_ENGINE:
                        continue;
                case TAG_RSA_LABEL:
                        continue;
                default:
                        bn = BN_bin2bn(priv.elements[i].data,
                                       priv.elements[i].length, NULL);
                        if (bn == NULL)
                                DST_RET(ISC_R_NOMEMORY);
                }

                switch (priv.elements[i].tag) {
                        case TAG_RSA_MODULUS:
                                rsa->n = bn;
                                break;
                        case TAG_RSA_PUBLICEXPONENT:
                                rsa->e = bn;
                                break;
                        case TAG_RSA_PRIVATEEXPONENT:
                                rsa->d = bn;
                                break;
                        case TAG_RSA_PRIME1:
                                rsa->p = bn;
                                break;
                        case TAG_RSA_PRIME2:
                                rsa->q = bn;
                                break;
                        case TAG_RSA_EXPONENT1:
                                rsa->dmp1 = bn;
                                break;
                        case TAG_RSA_EXPONENT2:
                                rsa->dmq1 = bn;
                                break;
                        case TAG_RSA_COEFFICIENT:
                                rsa->iqmp = bn;
                                break;
                }
        }
        dst__privstruct_free(&priv, mctx);
        memset(&priv, 0, sizeof(priv));

        if (rsa_check(rsa, pubrsa) != ISC_R_SUCCESS)
                DST_RET(DST_R_INVALIDPRIVATEKEY);
        if (BN_num_bits(rsa->e) > RSA_MAX_PUBEXP_BITS)
                DST_RET(ISC_R_RANGE);
        key->key_size = BN_num_bits(rsa->n);
        if (pubrsa != NULL)
                RSA_free(pubrsa);
#if USE_EVP
        RSA_free(rsa);
#endif

        return (ISC_R_SUCCESS);

 err:
#if USE_EVP
        if (pkey != NULL)
                EVP_PKEY_free(pkey);
#endif
        if (rsa != NULL)
                RSA_free(rsa);
        if (pubrsa != NULL)
                RSA_free(pubrsa);
        key->keydata.generic = NULL;
        dst__privstruct_free(&priv, mctx);
        memset(&priv, 0, sizeof(priv));
        return (ret);
}

static isc_result_t
opensslrsa_fromlabel(dst_key_t *key, const char *engine, const char *label,
                     const char *pin)
{
#ifdef USE_ENGINE
        ENGINE *e = NULL;
        isc_result_t ret;
        EVP_PKEY *pkey = NULL;
        RSA *rsa = NULL, *pubrsa = NULL;
        char *colon;

        UNUSED(pin);

        if (engine == NULL)
                DST_RET(DST_R_NOENGINE);
        e = dst__openssl_getengine(engine);
        if (e == NULL)
                DST_RET(DST_R_NOENGINE);
        pkey = ENGINE_load_public_key(e, label, NULL, NULL);
        if (pkey != NULL) {
                pubrsa = EVP_PKEY_get1_RSA(pkey);
                EVP_PKEY_free(pkey);
                if (pubrsa == NULL)
                        DST_RET(dst__openssl_toresult(DST_R_OPENSSLFAILURE));
        }
        pkey = ENGINE_load_private_key(e, label, NULL, NULL);
        if (pkey == NULL)
                DST_RET(dst__openssl_toresult2("ENGINE_load_private_key",
                                               ISC_R_NOTFOUND));
        if (engine != NULL) {
                key->engine = isc_mem_strdup(key->mctx, engine);
                if (key->engine == NULL)
                        DST_RET(ISC_R_NOMEMORY);
        } else {
                key->engine = isc_mem_strdup(key->mctx, label);
                if (key->engine == NULL)
                        DST_RET(ISC_R_NOMEMORY);
                colon = strchr(key->engine, ':');
                if (colon != NULL)
                        *colon = '\0';
        }
        key->label = isc_mem_strdup(key->mctx, label);
        if (key->label == NULL)
                DST_RET(ISC_R_NOMEMORY);
        rsa = EVP_PKEY_get1_RSA(pkey);
        if (rsa == NULL)
                DST_RET(dst__openssl_toresult(DST_R_OPENSSLFAILURE));
        if (rsa_check(rsa, pubrsa) != ISC_R_SUCCESS)
                DST_RET(DST_R_INVALIDPRIVATEKEY);
        if (BN_num_bits(rsa->e) > RSA_MAX_PUBEXP_BITS)
                DST_RET(ISC_R_RANGE);
        if (pubrsa != NULL)
                RSA_free(pubrsa);
        key->key_size = EVP_PKEY_bits(pkey);
#if USE_EVP
        key->keydata.pkey = pkey;
        RSA_free(rsa);
#else
        key->keydata.rsa = rsa;
        EVP_PKEY_free(pkey);
#endif
        return (ISC_R_SUCCESS);

 err:
        if (rsa != NULL)
                RSA_free(rsa);
        if (pubrsa != NULL)
                RSA_free(pubrsa);
        if (pkey != NULL)
                EVP_PKEY_free(pkey);
        return (ret);
#else
        UNUSED(key);
        UNUSED(engine);
        UNUSED(label);
        UNUSED(pin);
        return(DST_R_NOENGINE);
#endif
}

static dst_func_t opensslrsa_functions = {
        opensslrsa_createctx,
        NULL, /*%< createctx2 */
        opensslrsa_destroyctx,
        opensslrsa_adddata,
        opensslrsa_sign,
        opensslrsa_verify,
        opensslrsa_verify2,
        NULL, /*%< computesecret */
        opensslrsa_compare,
        NULL, /*%< paramcompare */
        opensslrsa_generate,
        opensslrsa_isprivate,
        opensslrsa_destroy,
        opensslrsa_todns,
        opensslrsa_fromdns,
        opensslrsa_tofile,
        opensslrsa_parse,
        NULL, /*%< cleanup */
        opensslrsa_fromlabel,
        NULL, /*%< dump */
        NULL, /*%< restore */
};

isc_result_t
dst__opensslrsa_init(dst_func_t **funcp, unsigned char algorithm) {
        REQUIRE(funcp != NULL);

        if (*funcp == NULL) {
                switch (algorithm) {
                case DST_ALG_RSASHA256:
#if defined(HAVE_EVP_SHA256) || !USE_EVP
                        *funcp = &opensslrsa_functions;
#endif
                        break;
                case DST_ALG_RSASHA512:
#if defined(HAVE_EVP_SHA512) || !USE_EVP
                        *funcp = &opensslrsa_functions;
#endif
                        break;
                default:
                        *funcp = &opensslrsa_functions;
                        break;
                }
        }
        return (ISC_R_SUCCESS);
}

#else /* OPENSSL */

#include <isc/util.h>

EMPTY_TRANSLATION_UNIT

#endif /* OPENSSL */
/*! \file */

---