/*

 * Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/*

 * ECDH and ECDSA low level APIs are deprecated for public use, but still ok

 * for internal use.

 */

#include "internal/deprecated.h"

#include <string.h>

#include <openssl/ec.h>

#ifndef FIPS_MODULE

#include <openssl/engine.h>

#endif

#include <openssl/err.h>

#include "ec_local.h"

static const EC_KEY_METHOD openssl_ec_key_method = {

    "OpenSSL EC_KEY method",

    0,

    0, 0, 0, 0, 0, 0,

    ossl_ec_key_gen,

    ossl_ecdh_compute_key,

    ossl_ecdsa_sign,

    ossl_ecdsa_sign_setup,

    ossl_ecdsa_sign_sig,

    ossl_ecdsa_verify,

    ossl_ecdsa_verify_sig

};

static const EC_KEY_METHOD *default_ec_key_meth = &openssl_ec_key_method;

const EC_KEY_METHOD *EC_KEY_OpenSSL(void)

{

    return &openssl_ec_key_method;

}

const EC_KEY_METHOD *EC_KEY_get_default_method(void)

{

    return default_ec_key_meth;

}

void EC_KEY_set_default_method(const EC_KEY_METHOD *meth)

{

    if (meth == NULL)

        default_ec_key_meth = &openssl_ec_key_method;

    else

        default_ec_key_meth = meth;

}

const EC_KEY_METHOD *EC_KEY_get_method(const EC_KEY *key)

{

    return key->meth;

}

int EC_KEY_set_method(EC_KEY *key, const EC_KEY_METHOD *meth)

{

    void (*finish)(EC_KEY *key) = key->meth->finish;

    if (finish != NULL)

        finish(key);

#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)

    ENGINE_finish(key->engine);

    key->engine = NULL;

#endif

    key->meth = meth;

    if (meth->init != NULL)

        return meth->init(key);

    return 1;

}

EC_KEY *ossl_ec_key_new_method_int(OSSL_LIB_CTX *libctx, const char *propq,

    ENGINE *engine)

{

    EC_KEY *ret = OPENSSL_zalloc(sizeof(*ret));

    if (ret == NULL) {

        ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);

        return NULL;

    }

    ret->libctx = libctx;

    if (propq != NULL) {

        ret->propq = OPENSSL_strdup(propq);

        if (ret->propq == NULL) {

            ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);

            goto err;

        }

    }

    ret->references = 1;

    ret->lock = CRYPTO_THREAD_lock_new();

    if (ret->lock == NULL) {

        ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    ret->meth = EC_KEY_get_default_method();

#if !defined(OPENSSL_NO_ENGINE) && !defined(FIPS_MODULE)

    if (engine != NULL) {

        if (!ENGINE_init(engine)) {

            ERR_raise(ERR_LIB_EC, ERR_R_ENGINE_LIB);

            goto err;

        }

        ret->engine = engine;

    } else

        ret->engine = ENGINE_get_default_EC();

    if (ret->engine != NULL) {

        ret->meth = ENGINE_get_EC(ret->engine);

        if (ret->meth == NULL) {

            ERR_raise(ERR_LIB_EC, ERR_R_ENGINE_LIB);

            goto err;

        }

    }

#endif

    ret->version = 1;

    ret->conv_form = POINT_CONVERSION_UNCOMPRESSED;

/* No ex_data inside the FIPS provider */

#ifndef FIPS_MODULE

    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_EC_KEY, ret, &ret->ex_data)) {

        goto err;

    }

#endif

    if (ret->meth->init != NULL && ret->meth->init(ret) == 0) {

        ERR_raise(ERR_LIB_EC, ERR_R_INIT_FAIL);

        goto err;

    }

    return ret;

err:

    EC_KEY_free(ret);

    return NULL;

}

#ifndef FIPS_MODULE

EC_KEY *EC_KEY_new_method(ENGINE *engine)

{

    return ossl_ec_key_new_method_int(NULL, NULL, engine);

}

#endif

int ECDH_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,

    const EC_KEY *eckey,

    void *(*KDF)(const void *in, size_t inlen, void *out,

        size_t *outlen))

{

    unsigned char *sec = NULL;

    size_t seclen;

    if (eckey->meth->compute_key == NULL) {

        ERR_raise(ERR_LIB_EC, EC_R_OPERATION_NOT_SUPPORTED);

        return 0;

    }

    if (outlen > INT_MAX) {

        ERR_raise(ERR_LIB_EC, EC_R_INVALID_OUTPUT_LENGTH);

        return 0;

    }

    if (!eckey->meth->compute_key(&sec, &seclen, pub_key, eckey))

        return 0;

    if (KDF != NULL) {

        KDF(sec, seclen, out, &outlen);

    } else {

        if (outlen > seclen)

            outlen = seclen;

        memcpy(out, sec, outlen);

    }

    OPENSSL_clear_free(sec, seclen);

    return outlen;

}

EC_KEY_METHOD *EC_KEY_METHOD_new(const EC_KEY_METHOD *meth)

{

    EC_KEY_METHOD *ret = OPENSSL_zalloc(sizeof(*meth));

    if (ret == NULL)

        return NULL;

    if (meth != NULL)

        *ret = *meth;

    ret->flags |= EC_KEY_METHOD_DYNAMIC;

    return ret;

}

void EC_KEY_METHOD_free(EC_KEY_METHOD *meth)

{

    if (meth->flags & EC_KEY_METHOD_DYNAMIC)

        OPENSSL_free(meth);

}

void EC_KEY_METHOD_set_init(EC_KEY_METHOD *meth,

    int (*init)(EC_KEY *key),

    void (*finish)(EC_KEY *key),

    int (*copy)(EC_KEY *dest, const EC_KEY *src),

    int (*set_group)(EC_KEY *key, const EC_GROUP *grp),

    int (*set_private)(EC_KEY *key,

        const BIGNUM *priv_key),

    int (*set_public)(EC_KEY *key,

        const EC_POINT *pub_key))

{

    meth->init = init;

    meth->finish = finish;

    meth->copy = copy;

    meth->set_group = set_group;

    meth->set_private = set_private;

    meth->set_public = set_public;

}

void EC_KEY_METHOD_set_keygen(EC_KEY_METHOD *meth,

    int (*keygen)(EC_KEY *key))

{

    meth->keygen = keygen;

}

void EC_KEY_METHOD_set_compute_key(EC_KEY_METHOD *meth,

    int (*ckey)(unsigned char **psec,

        size_t *pseclen,

        const EC_POINT *pub_key,

        const EC_KEY *ecdh))

{

    meth->compute_key = ckey;

}

void EC_KEY_METHOD_set_sign(EC_KEY_METHOD *meth,

    int (*sign)(int type, const unsigned char *dgst,

        int dlen, unsigned char *sig,

        unsigned int *siglen,

        const BIGNUM *kinv, const BIGNUM *r,

        EC_KEY *eckey),

    int (*sign_setup)(EC_KEY *eckey, BN_CTX *ctx_in,

        BIGNUM **kinvp, BIGNUM **rp),

    ECDSA_SIG *(*sign_sig)(const unsigned char *dgst,

        int dgst_len,

        const BIGNUM *in_kinv,

        const BIGNUM *in_r,

        EC_KEY *eckey))

{

    meth->sign = sign;

    meth->sign_setup = sign_setup;

    meth->sign_sig = sign_sig;

}

void EC_KEY_METHOD_set_verify(EC_KEY_METHOD *meth,

    int (*verify)(int type, const unsigned char *dgst, int dgst_len,

        const unsigned char *sigbuf,

        int sig_len, EC_KEY *eckey),

    int (*verify_sig)(const unsigned char *dgst,

        int dgst_len,

        const ECDSA_SIG *sig,

        EC_KEY *eckey))

{

    meth->verify = verify;

    meth->verify_sig = verify_sig;

}

void EC_KEY_METHOD_get_init(const EC_KEY_METHOD *meth,

    int (**pinit)(EC_KEY *key),

    void (**pfinish)(EC_KEY *key),

    int (**pcopy)(EC_KEY *dest, const EC_KEY *src),

    int (**pset_group)(EC_KEY *key,

        const EC_GROUP *grp),

    int (**pset_private)(EC_KEY *key,

        const BIGNUM *priv_key),

    int (**pset_public)(EC_KEY *key,

        const EC_POINT *pub_key))

{

    if (pinit != NULL)

        *pinit = meth->init;

    if (pfinish != NULL)

        *pfinish = meth->finish;

    if (pcopy != NULL)

        *pcopy = meth->copy;

    if (pset_group != NULL)

        *pset_group = meth->set_group;

    if (pset_private != NULL)

        *pset_private = meth->set_private;

    if (pset_public != NULL)

        *pset_public = meth->set_public;

}

void EC_KEY_METHOD_get_keygen(const EC_KEY_METHOD *meth,

    int (**pkeygen)(EC_KEY *key))

{

    if (pkeygen != NULL)

        *pkeygen = meth->keygen;

}

void EC_KEY_METHOD_get_compute_key(const EC_KEY_METHOD *meth,

    int (**pck)(unsigned char **pout,

        size_t *poutlen,

        const EC_POINT *pub_key,

        const EC_KEY *ecdh))

{

    if (pck != NULL)

        *pck = meth->compute_key;

}

void EC_KEY_METHOD_get_sign(const EC_KEY_METHOD *meth,

    int (**psign)(int type, const unsigned char *dgst,

        int dlen, unsigned char *sig,

        unsigned int *siglen,

        const BIGNUM *kinv, const BIGNUM *r,

        EC_KEY *eckey),

    int (**psign_setup)(EC_KEY *eckey, BN_CTX *ctx_in,

        BIGNUM **kinvp, BIGNUM **rp),

    ECDSA_SIG *(**psign_sig)(const unsigned char *dgst,

        int dgst_len,

        const BIGNUM *in_kinv,

        const BIGNUM *in_r,

        EC_KEY *eckey))

{

    if (psign != NULL)

        *psign = meth->sign;

    if (psign_setup != NULL)

        *psign_setup = meth->sign_setup;

    if (psign_sig != NULL)

        *psign_sig = meth->sign_sig;

}

void EC_KEY_METHOD_get_verify(const EC_KEY_METHOD *meth,

    int (**pverify)(int type, const unsigned char *dgst, int dgst_len,

        const unsigned char *sigbuf,

        int sig_len, EC_KEY *eckey),

    int (**pverify_sig)(const unsigned char *dgst,

        int dgst_len,

        const ECDSA_SIG *sig,

        EC_KEY *eckey))

{

    if (pverify != NULL)

        *pverify = meth->verify;

    if (pverify_sig != NULL)

        *pverify_sig = meth->verify_sig;

}