lib/dns/opensslrsa_link.c

	opensslrsa_link.c revision 016c0a82f1ce3fe4d362d7c9cf8de4377ffaf5a9
/*
 * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND 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: opensslrsa_link.c,v 1.4 2005/06/17 02:22:44 marka Exp $
 */
#ifdef OPENSSL

#include <config.h>

#include <isc/entropy.h>
#include <isc/md5.h>
#include <isc/sha1.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>

    /*
     * XXXMPA  Temporarially disable RSA_BLINDING as it requires
     * good quality random data that cannot currently be guarenteed.
     * 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)
#else
#define SET_FLAGS(rsa) \
    do { \
        (rsa)->flags &= ~RSA_FLAG_BLINDING; \
    } while (0)
#endif

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) {
    UNUSED(key);
    REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
        dctx->key->key_alg == DST_ALG_RSASHA1);

    if (dctx->key->key_alg == DST_ALG_RSAMD5) {
        isc_md5_t *md5ctx;

        md5ctx = isc_mem_get(dctx->mctx, sizeof(isc_md5_t));
        isc_md5_init(md5ctx);
        dctx->opaque = md5ctx;
    } else {
        isc_sha1_t *sha1ctx;

        sha1ctx = isc_mem_get(dctx->mctx, sizeof(isc_sha1_t));
        isc_sha1_init(sha1ctx);
        dctx->opaque = sha1ctx;
    }

    return (ISC_R_SUCCESS);
}

static void
opensslrsa_destroyctx(dst_context_t *dctx) {
    REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
        dctx->key->key_alg == DST_ALG_RSASHA1);

    if (dctx->key->key_alg == DST_ALG_RSAMD5) {
        isc_md5_t *md5ctx = dctx->opaque;

        if (md5ctx != NULL) {
            isc_md5_invalidate(md5ctx);
            isc_mem_put(dctx->mctx, md5ctx, sizeof(isc_md5_t));
        }
    } else {
        isc_sha1_t *sha1ctx = dctx->opaque;

        if (sha1ctx != NULL) {
            isc_sha1_invalidate(sha1ctx);
            isc_mem_put(dctx->mctx, sha1ctx, sizeof(isc_sha1_t));
        }
    }
    dctx->opaque = NULL;
}

static isc_result_t
opensslrsa_adddata(dst_context_t *dctx, const isc_region_t *data) {
    REQUIRE(dctx->key->key_alg == DST_ALG_RSAMD5 ||
        dctx->key->key_alg == DST_ALG_RSASHA1);

    if (dctx->key->key_alg == DST_ALG_RSAMD5) {
        isc_md5_t *md5ctx = dctx->opaque;
        isc_md5_update(md5ctx, data->base, data->length);
    } else {
        isc_sha1_t *sha1ctx = dctx->opaque;
        isc_sha1_update(sha1ctx, data->base, data->length);
    }
    return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_sign(dst_context_t *dctx, isc_buffer_t *sig) {
    dst_key_t *key = dctx->key;
    RSA *rsa = key->opaque;
    isc_region_t r;
    /* note: ISC_SHA1_DIGESTLENGTH > ISC_MD5_DIGESTLENGTH */
    unsigned char digest[ISC_SHA1_DIGESTLENGTH];
    unsigned int siglen = 0;
    int status;
    int type;
    unsigned int digestlen;
    char *message;
    unsigned long err;
    const char* file;
    int line;

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

    isc_buffer_availableregion(sig, &r);

    if (r.length < (unsigned int) RSA_size(rsa))
        return (ISC_R_NOSPACE);

    if (dctx->key->key_alg == DST_ALG_RSAMD5) {
        isc_md5_t *md5ctx = dctx->opaque;
        isc_md5_final(md5ctx, digest);
        type = NID_md5;
        digestlen = ISC_MD5_DIGESTLENGTH;
    } else {
        isc_sha1_t *sha1ctx = dctx->opaque;
        isc_sha1_final(sha1ctx, digest);
        type = NID_sha1;
        digestlen = ISC_SHA1_DIGESTLENGTH;
    }

    status = RSA_sign(type, digest, digestlen, r.base, &siglen, rsa);
    if (status == 0) {
        err = ERR_peek_error_line(&file, &line);
        if (err != 0U) {
            message = ERR_error_string(err, NULL);
            fprintf(stderr, "%s:%s:%d\n", message,
                file ? file : "", line);
        }
        return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
    }

    isc_buffer_add(sig, siglen);

    return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_verify(dst_context_t *dctx, const isc_region_t *sig) {
    dst_key_t *key = dctx->key;
    RSA *rsa = key->opaque;
    /* note: ISC_SHA1_DIGESTLENGTH > ISC_MD5_DIGESTLENGTH */
    unsigned char digest[ISC_SHA1_DIGESTLENGTH];
    int status = 0;
    int type;
    unsigned int digestlen;

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

    if (dctx->key->key_alg == DST_ALG_RSAMD5) {
        isc_md5_t *md5ctx = dctx->opaque;
        isc_md5_final(md5ctx, digest);
        type = NID_md5;
        digestlen = ISC_MD5_DIGESTLENGTH;
    } else {
        isc_sha1_t *sha1ctx = dctx->opaque;
        isc_sha1_final(sha1ctx, digest);
        type = NID_sha1;
        digestlen = ISC_SHA1_DIGESTLENGTH;
    }

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

    status = RSA_verify(type, digest, digestlen, sig->base,
                RSA_size(rsa), rsa);
    if (status == 0)
        return (dst__openssl_toresult(DST_R_VERIFYFAILURE));

    return (ISC_R_SUCCESS);
}

static isc_boolean_t
opensslrsa_compare(const dst_key_t *key1, const dst_key_t *key2) {
    int status;
    RSA *rsa1, *rsa2;

    rsa1 = (RSA *) key1->opaque;
    rsa2 = (RSA *) key2->opaque;

    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 (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);
}

static isc_result_t
opensslrsa_generate(dst_key_t *key, int exp) {
    RSA *rsa;
    unsigned long e;

    if (exp == 0)
        e = RSA_3;
    else
        e = RSA_F4;
    rsa = RSA_generate_key(key->key_size, e, NULL, NULL);
    if (rsa == NULL)
        return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
    SET_FLAGS(rsa);
    key->opaque = rsa;

    return (ISC_R_SUCCESS);
}

static isc_boolean_t
opensslrsa_isprivate(const dst_key_t *key) {
    RSA *rsa = (RSA *) key->opaque;
    return (ISC_TF(rsa != NULL && rsa->d != NULL));
}

static void
opensslrsa_destroy(dst_key_t *key) {
    RSA *rsa = key->opaque;
    RSA_free(rsa);
    key->opaque = NULL;
}


static isc_result_t
opensslrsa_todns(const dst_key_t *key, isc_buffer_t *data) {
    RSA *rsa;
    isc_region_t r;
    unsigned int e_bytes;
    unsigned int mod_bytes;

    REQUIRE(key->opaque != NULL);

    rsa = (RSA *) key->opaque;

    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)
            return (ISC_R_NOSPACE);
        isc_buffer_putuint8(data, (isc_uint8_t) e_bytes);
    } else {
        if (r.length < 3)
            return (ISC_R_NOSPACE);
        isc_buffer_putuint8(data, 0);
        isc_buffer_putuint16(data, (isc_uint16_t) e_bytes);
    }

    if (r.length < e_bytes + mod_bytes)
        return (ISC_R_NOSPACE);
    isc_buffer_availableregion(data, &r);

    BN_bn2bin(rsa->e, r.base);
    r.base += e_bytes;
    BN_bn2bin(rsa->n, r.base);

    isc_buffer_add(data, e_bytes + mod_bytes);

    return (ISC_R_SUCCESS);
}

static isc_result_t
opensslrsa_fromdns(dst_key_t *key, isc_buffer_t *data) {
    RSA *rsa;
    isc_region_t r;
    unsigned int e_bytes;

    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);

    key->opaque = (void *) rsa;

    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 (key->opaque == NULL)
        return (DST_R_NULLKEY);

    rsa = (RSA *) key->opaque;

    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++;

    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++;

    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++;

    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++;

    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++;

    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++;

    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++;

    priv.nelements = i;
    result =  dst__privstruct_writefile(key, &priv, directory);
 fail:
    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
opensslrsa_parse(dst_key_t *key, isc_lex_t *lexer) {
    dst_private_t priv;
    isc_result_t ret;
    int i;
    RSA *rsa = NULL;
    isc_mem_t *mctx = key->mctx;
#define DST_RET(a) {ret = a; goto err;}

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

    rsa = RSA_new();
    if (rsa == NULL)
        DST_RET(ISC_R_NOMEMORY);
    SET_FLAGS(rsa);
    key->opaque = rsa;

    for (i = 0; i < priv.nelements; i++) {
        BIGNUM *bn;
        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);

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

    return (ISC_R_SUCCESS);

 err:
    opensslrsa_destroy(key);
    dst__privstruct_free(&priv, mctx);
    memset(&priv, 0, sizeof(priv));
    return (ret);
}

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

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

#else /* OPENSSL */

#include <isc/util.h>

EMPTY_TRANSLATION_UNIT

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