p_lib.c

/*
 * Copyright 1995-2018 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
 */

#include <stdio.h>
#include "internal/cryptlib.h"
#include "internal/refcount.h"
#include <openssl/bn.h>
#include <openssl/err.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <openssl/rsa.h>
#include <openssl/dsa.h>
#include <openssl/dh.h>
#include <openssl/cmac.h>
#include <openssl/engine.h>
#include <openssl/params.h>
#include <openssl/core_names.h>

#include "internal/asn1_int.h"
#include "internal/evp_int.h"
#include "internal/provider.h"

static void EVP_PKEY_free_it(EVP_PKEY *x);

int EVP_PKEY_bits(const EVP_PKEY *pkey)
{
    if (pkey && pkey->ameth && pkey->ameth->pkey_bits)
        return pkey->ameth->pkey_bits(pkey);
    return 0;
}

int EVP_PKEY_security_bits(const EVP_PKEY *pkey)
{
    if (pkey == NULL)
        return 0;
    if (!pkey->ameth || !pkey->ameth->pkey_security_bits)
        return -2;
    return pkey->ameth->pkey_security_bits(pkey);
}

int EVP_PKEY_size(const EVP_PKEY *pkey)
{
    if (pkey && pkey->ameth && pkey->ameth->pkey_size)
        return pkey->ameth->pkey_size(pkey);
    return 0;
}

int EVP_PKEY_save_parameters(EVP_PKEY *pkey, int mode)
{
#ifndef OPENSSL_NO_DSA
    if (pkey->type == EVP_PKEY_DSA) {
        int ret = pkey->save_parameters;

        if (mode >= 0)
            pkey->save_parameters = mode;
        return ret;
    }
#endif
#ifndef OPENSSL_NO_EC
    if (pkey->type == EVP_PKEY_EC) {
        int ret = pkey->save_parameters;

        if (mode >= 0)
            pkey->save_parameters = mode;
        return ret;
    }
#endif
    return 0;
}

int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
{
    if (to->type == EVP_PKEY_NONE) {
        if (EVP_PKEY_set_type(to, from->type) == 0)
            return 0;
    } else if (to->type != from->type) {
        EVPerr(EVP_F_EVP_PKEY_COPY_PARAMETERS, EVP_R_DIFFERENT_KEY_TYPES);
        goto err;
    }

    if (EVP_PKEY_missing_parameters(from)) {
        EVPerr(EVP_F_EVP_PKEY_COPY_PARAMETERS, EVP_R_MISSING_PARAMETERS);
        goto err;
    }

    if (!EVP_PKEY_missing_parameters(to)) {
        if (EVP_PKEY_cmp_parameters(to, from) == 1)
            return 1;
        EVPerr(EVP_F_EVP_PKEY_COPY_PARAMETERS, EVP_R_DIFFERENT_PARAMETERS);
        return 0;
    }

    if (from->ameth && from->ameth->param_copy)
        return from->ameth->param_copy(to, from);
 err:
    return 0;
}

int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey)
{
    if (pkey->ameth && pkey->ameth->param_missing)
        return pkey->ameth->param_missing(pkey);
    return 0;
}

int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
{
    if (a->type != b->type)
        return -1;
    if (a->ameth && a->ameth->param_cmp)
        return a->ameth->param_cmp(a, b);
    return -2;
}

int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
    if (a->type != b->type)
        return -1;

    if (a->ameth) {
        int ret;
        /* Compare parameters if the algorithm has them */
        if (a->ameth->param_cmp) {
            ret = a->ameth->param_cmp(a, b);
            if (ret <= 0)
                return ret;
        }

        if (a->ameth->pub_cmp)
            return a->ameth->pub_cmp(a, b);
    }

    return -2;
}

EVP_PKEY *EVP_PKEY_new(void)
{
    EVP_PKEY *ret = OPENSSL_zalloc(sizeof(*ret));

    if (ret == NULL) {
        EVPerr(EVP_F_EVP_PKEY_NEW, ERR_R_MALLOC_FAILURE);
        return NULL;
    }
    ret->type = EVP_PKEY_NONE;
    ret->save_type = EVP_PKEY_NONE;
    ret->references = 1;
    ret->save_parameters = 1;
    ret->lock = CRYPTO_THREAD_lock_new();
    if (ret->lock == NULL) {
        EVPerr(EVP_F_EVP_PKEY_NEW, ERR_R_MALLOC_FAILURE);
        OPENSSL_free(ret);
        return NULL;
    }
    return ret;
}

int EVP_PKEY_up_ref(EVP_PKEY *pkey)
{
    int i;

    if (CRYPTO_UP_REF(&pkey->references, &i, pkey->lock) <= 0)
        return 0;

    REF_PRINT_COUNT("EVP_PKEY", pkey);
    REF_ASSERT_ISNT(i < 2);
    return ((i > 1) ? 1 : 0);
}

/*
 * Setup a public key ASN1 method and ENGINE from a NID or a string. If pkey
 * is NULL just return 1 or 0 if the algorithm exists.
 */

static int pkey_set_type(EVP_PKEY *pkey, ENGINE *e, int type, const char *str,
                         int len)
{
    const EVP_PKEY_ASN1_METHOD *ameth;
    ENGINE **eptr = (e == NULL) ? &e :  NULL;

    if (pkey) {
        if (pkey->pkey.ptr)
            EVP_PKEY_free_it(pkey);
        /*
         * If key type matches and a method exists then this lookup has
         * succeeded once so just indicate success.
         */
        if ((type == pkey->save_type) && pkey->ameth)
            return 1;
#ifndef OPENSSL_NO_ENGINE
        /* If we have ENGINEs release them */
        ENGINE_finish(pkey->engine);
        pkey->engine = NULL;
        ENGINE_finish(pkey->pmeth_engine);
        pkey->pmeth_engine = NULL;
#endif
    }
    if (str)
        ameth = EVP_PKEY_asn1_find_str(eptr, str, len);
    else
        ameth = EVP_PKEY_asn1_find(eptr, type);
#ifndef OPENSSL_NO_ENGINE
    if (pkey == NULL && eptr != NULL)
        ENGINE_finish(e);
#endif
    if (ameth == NULL) {
        EVPerr(EVP_F_PKEY_SET_TYPE, EVP_R_UNSUPPORTED_ALGORITHM);
        return 0;
    }
    if (pkey) {
        pkey->ameth = ameth;
        pkey->engine = e;

        pkey->type = pkey->ameth->pkey_id;
        pkey->save_type = type;
    }
    return 1;
}

EVP_PKEY *EVP_PKEY_new_raw_private_key(int type, ENGINE *e,
                                       const unsigned char *priv,
                                       size_t len)
{
    EVP_PKEY *ret = EVP_PKEY_new();

    if (ret == NULL
            || !pkey_set_type(ret, e, type, NULL, -1)) {
        /* EVPerr already called */
        goto err;
    }

    if (ret->ameth->set_priv_key == NULL) {
        EVPerr(EVP_F_EVP_PKEY_NEW_RAW_PRIVATE_KEY,
               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
        goto err;
    }

    if (!ret->ameth->set_priv_key(ret, priv, len)) {
        EVPerr(EVP_F_EVP_PKEY_NEW_RAW_PRIVATE_KEY, EVP_R_KEY_SETUP_FAILED);
        goto err;
    }

    return ret;

 err:
    EVP_PKEY_free(ret);
    return NULL;
}

EVP_PKEY *EVP_PKEY_new_raw_public_key(int type, ENGINE *e,
                                      const unsigned char *pub,
                                      size_t len)
{
    EVP_PKEY *ret = EVP_PKEY_new();

    if (ret == NULL
            || !pkey_set_type(ret, e, type, NULL, -1)) {
        /* EVPerr already called */
        goto err;
    }

    if (ret->ameth->set_pub_key == NULL) {
        EVPerr(EVP_F_EVP_PKEY_NEW_RAW_PUBLIC_KEY,
               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
        goto err;
    }

    if (!ret->ameth->set_pub_key(ret, pub, len)) {
        EVPerr(EVP_F_EVP_PKEY_NEW_RAW_PUBLIC_KEY, EVP_R_KEY_SETUP_FAILED);
        goto err;
    }

    return ret;

 err:
    EVP_PKEY_free(ret);
    return NULL;
}

int EVP_PKEY_get_raw_private_key(const EVP_PKEY *pkey, unsigned char *priv,
                                 size_t *len)
{
     if (pkey->ameth->get_priv_key == NULL) {
        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PRIVATE_KEY,
               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
        return 0;
    }

    if (!pkey->ameth->get_priv_key(pkey, priv, len)) {
        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PRIVATE_KEY, EVP_R_GET_RAW_KEY_FAILED);
        return 0;
    }

    return 1;
}

int EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
                                size_t *len)
{
     if (pkey->ameth->get_pub_key == NULL) {
        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PUBLIC_KEY,
               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
        return 0;
    }

    if (!pkey->ameth->get_pub_key(pkey, pub, len)) {
        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PUBLIC_KEY, EVP_R_GET_RAW_KEY_FAILED);
        return 0;
    }

    return 1;
}

EVP_PKEY *EVP_PKEY_new_CMAC_key(ENGINE *e, const unsigned char *priv,
                                size_t len, const EVP_CIPHER *cipher)
{
#ifndef OPENSSL_NO_CMAC
# ifndef OPENSSL_NO_ENGINE
    const char *engine_id = e != NULL ? ENGINE_get_id(e) : NULL;
# endif
    const char *cipher_name = EVP_CIPHER_name(cipher);
    const OSSL_PROVIDER *prov = EVP_CIPHER_provider(cipher);
    OPENSSL_CTX *libctx =
        prov == NULL ? NULL : ossl_provider_library_context(prov);
    EVP_PKEY *ret = EVP_PKEY_new();
    EVP_MAC *cmac = EVP_MAC_fetch(libctx, OSSL_MAC_NAME_CMAC, NULL);
    EVP_MAC_CTX *cmctx = cmac != NULL ? EVP_MAC_CTX_new(cmac) : NULL;
    OSSL_PARAM params[4];
    size_t paramsn = 0;

    if (ret == NULL
            || cmctx == NULL
            || !pkey_set_type(ret, e, EVP_PKEY_CMAC, NULL, -1)) {
        /* EVPerr already called */
        goto err;
    }

# ifndef OPENSSL_NO_ENGINE
    if (engine_id != NULL)
        params[paramsn++] =
            OSSL_PARAM_construct_utf8_string("engine", (char *)engine_id, 0);
# endif

    params[paramsn++] =
        OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_CIPHER,
                                         (char *)cipher_name, 0);
    params[paramsn++] =
        OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
                                          (char *)priv, len);
    params[paramsn] = OSSL_PARAM_construct_end();

    if (!EVP_MAC_CTX_set_params(cmctx, params)) {
        EVPerr(EVP_F_EVP_PKEY_NEW_CMAC_KEY, EVP_R_KEY_SETUP_FAILED);
        goto err;
    }

    ret->pkey.ptr = cmctx;
    return ret;

 err:
    EVP_PKEY_free(ret);
    EVP_MAC_CTX_free(cmctx);
    EVP_MAC_free(cmac);
    return NULL;
#else
    EVPerr(EVP_F_EVP_PKEY_NEW_CMAC_KEY,
           EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
    return NULL;
#endif
}

int EVP_PKEY_set_type(EVP_PKEY *pkey, int type)
{
    return pkey_set_type(pkey, NULL, type, NULL, -1);
}

int EVP_PKEY_set_type_str(EVP_PKEY *pkey, const char *str, int len)
{
    return pkey_set_type(pkey, NULL, EVP_PKEY_NONE, str, len);
}

int EVP_PKEY_set_alias_type(EVP_PKEY *pkey, int type)
{
    if (pkey->type == type) {
        return 1; /* it already is that type */
    }

    /*
     * The application is requesting to alias this to a different pkey type,
     * but not one that resolves to the base type.
     */
    if (EVP_PKEY_type(type) != EVP_PKEY_base_id(pkey)) {
        EVPerr(EVP_F_EVP_PKEY_SET_ALIAS_TYPE, EVP_R_UNSUPPORTED_ALGORITHM);
        return 0;
    }

    pkey->type = type;
    return 1;
}

#ifndef OPENSSL_NO_ENGINE
int EVP_PKEY_set1_engine(EVP_PKEY *pkey, ENGINE *e)
{
    if (e != NULL) {
        if (!ENGINE_init(e)) {
            EVPerr(EVP_F_EVP_PKEY_SET1_ENGINE, ERR_R_ENGINE_LIB);
            return 0;
        }
        if (ENGINE_get_pkey_meth(e, pkey->type) == NULL) {
            ENGINE_finish(e);
            EVPerr(EVP_F_EVP_PKEY_SET1_ENGINE, EVP_R_UNSUPPORTED_ALGORITHM);
            return 0;
        }
    }
    ENGINE_finish(pkey->pmeth_engine);
    pkey->pmeth_engine = e;
    return 1;
}

ENGINE *EVP_PKEY_get0_engine(const EVP_PKEY *pkey)
{
    return pkey->engine;
}
#endif
int EVP_PKEY_assign(EVP_PKEY *pkey, int type, void *key)
{
    if (pkey == NULL || !EVP_PKEY_set_type(pkey, type))
        return 0;
    pkey->pkey.ptr = key;
    return (key != NULL);
}

void *EVP_PKEY_get0(const EVP_PKEY *pkey)
{
    return pkey->pkey.ptr;
}

const unsigned char *EVP_PKEY_get0_hmac(const EVP_PKEY *pkey, size_t *len)
{
    ASN1_OCTET_STRING *os = NULL;
    if (pkey->type != EVP_PKEY_HMAC) {
        EVPerr(EVP_F_EVP_PKEY_GET0_HMAC, EVP_R_EXPECTING_AN_HMAC_KEY);
        return NULL;
    }
    os = EVP_PKEY_get0(pkey);
    *len = os->length;
    return os->data;
}

#ifndef OPENSSL_NO_POLY1305
const unsigned char *EVP_PKEY_get0_poly1305(const EVP_PKEY *pkey, size_t *len)
{
    ASN1_OCTET_STRING *os = NULL;
    if (pkey->type != EVP_PKEY_POLY1305) {
        EVPerr(EVP_F_EVP_PKEY_GET0_POLY1305, EVP_R_EXPECTING_A_POLY1305_KEY);
        return NULL;
    }
    os = EVP_PKEY_get0(pkey);
    *len = os->length;
    return os->data;
}
#endif

#ifndef OPENSSL_NO_SIPHASH
const unsigned char *EVP_PKEY_get0_siphash(const EVP_PKEY *pkey, size_t *len)
{
    ASN1_OCTET_STRING *os = NULL;

    if (pkey->type != EVP_PKEY_SIPHASH) {
        EVPerr(EVP_F_EVP_PKEY_GET0_SIPHASH, EVP_R_EXPECTING_A_SIPHASH_KEY);
        return NULL;
    }
    os = EVP_PKEY_get0(pkey);
    *len = os->length;
    return os->data;
}
#endif

#ifndef OPENSSL_NO_RSA
int EVP_PKEY_set1_RSA(EVP_PKEY *pkey, RSA *key)
{
    int ret = EVP_PKEY_assign_RSA(pkey, key);
    if (ret)
        RSA_up_ref(key);
    return ret;
}

RSA *EVP_PKEY_get0_RSA(const EVP_PKEY *pkey)
{
    if (pkey->type != EVP_PKEY_RSA) {
        EVPerr(EVP_F_EVP_PKEY_GET0_RSA, EVP_R_EXPECTING_AN_RSA_KEY);
        return NULL;
    }
    return pkey->pkey.rsa;
}

RSA *EVP_PKEY_get1_RSA(EVP_PKEY *pkey)
{
    RSA *ret = EVP_PKEY_get0_RSA(pkey);
    if (ret != NULL)
        RSA_up_ref(ret);
    return ret;
}
#endif

#ifndef OPENSSL_NO_DSA
int EVP_PKEY_set1_DSA(EVP_PKEY *pkey, DSA *key)
{
    int ret = EVP_PKEY_assign_DSA(pkey, key);
    if (ret)
        DSA_up_ref(key);
    return ret;
}

DSA *EVP_PKEY_get0_DSA(const EVP_PKEY *pkey)
{
    if (pkey->type != EVP_PKEY_DSA) {
        EVPerr(EVP_F_EVP_PKEY_GET0_DSA, EVP_R_EXPECTING_A_DSA_KEY);
        return NULL;
    }
    return pkey->pkey.dsa;
}

DSA *EVP_PKEY_get1_DSA(EVP_PKEY *pkey)
{
    DSA *ret = EVP_PKEY_get0_DSA(pkey);
    if (ret != NULL)
        DSA_up_ref(ret);
    return ret;
}
#endif

#ifndef OPENSSL_NO_EC

int EVP_PKEY_set1_EC_KEY(EVP_PKEY *pkey, EC_KEY *key)
{
    int ret = EVP_PKEY_assign_EC_KEY(pkey, key);
    if (ret)
        EC_KEY_up_ref(key);
    return ret;
}

EC_KEY *EVP_PKEY_get0_EC_KEY(const EVP_PKEY *pkey)
{
    if (pkey->type != EVP_PKEY_EC) {
        EVPerr(EVP_F_EVP_PKEY_GET0_EC_KEY, EVP_R_EXPECTING_A_EC_KEY);
        return NULL;
    }
    return pkey->pkey.ec;
}

EC_KEY *EVP_PKEY_get1_EC_KEY(EVP_PKEY *pkey)
{
    EC_KEY *ret = EVP_PKEY_get0_EC_KEY(pkey);
    if (ret != NULL)
        EC_KEY_up_ref(ret);
    return ret;
}
#endif

#ifndef OPENSSL_NO_DH

int EVP_PKEY_set1_DH(EVP_PKEY *pkey, DH *key)
{
    int ret = EVP_PKEY_assign_DH(pkey, key);
    if (ret)
        DH_up_ref(key);
    return ret;
}

DH *EVP_PKEY_get0_DH(const EVP_PKEY *pkey)
{
    if (pkey->type != EVP_PKEY_DH && pkey->type != EVP_PKEY_DHX) {
        EVPerr(EVP_F_EVP_PKEY_GET0_DH, EVP_R_EXPECTING_A_DH_KEY);
        return NULL;
    }
    return pkey->pkey.dh;
}

DH *EVP_PKEY_get1_DH(EVP_PKEY *pkey)
{
    DH *ret = EVP_PKEY_get0_DH(pkey);
    if (ret != NULL)
        DH_up_ref(ret);
    return ret;
}
#endif

int EVP_PKEY_type(int type)
{
    int ret;
    const EVP_PKEY_ASN1_METHOD *ameth;
    ENGINE *e;
    ameth = EVP_PKEY_asn1_find(&e, type);
    if (ameth)
        ret = ameth->pkey_id;
    else
        ret = NID_undef;
#ifndef OPENSSL_NO_ENGINE
    ENGINE_finish(e);
#endif
    return ret;
}

int EVP_PKEY_id(const EVP_PKEY *pkey)
{
    return pkey->type;
}

int EVP_PKEY_base_id(const EVP_PKEY *pkey)
{
    return EVP_PKEY_type(pkey->type);
}

void EVP_PKEY_free(EVP_PKEY *x)
{
    int i;

    if (x == NULL)
        return;

    CRYPTO_DOWN_REF(&x->references, &i, x->lock);
    REF_PRINT_COUNT("EVP_PKEY", x);
    if (i > 0)
        return;
    REF_ASSERT_ISNT(i < 0);
    EVP_PKEY_free_it(x);
    CRYPTO_THREAD_lock_free(x->lock);
    sk_X509_ATTRIBUTE_pop_free(x->attributes, X509_ATTRIBUTE_free);
    OPENSSL_free(x);
}

static void EVP_PKEY_free_it(EVP_PKEY *x)
{
    /* internal function; x is never NULL */

    evp_keymgmt_clear_pkey_cache(x);

    if (x->ameth && x->ameth->pkey_free) {
        x->ameth->pkey_free(x);
        x->pkey.ptr = NULL;
    }
#ifndef OPENSSL_NO_ENGINE
    ENGINE_finish(x->engine);
    x->engine = NULL;
    ENGINE_finish(x->pmeth_engine);
    x->pmeth_engine = NULL;
#endif
}

static int unsup_alg(BIO *out, const EVP_PKEY *pkey, int indent,
                     const char *kstr)
{
    BIO_indent(out, indent, 128);
    BIO_printf(out, "%s algorithm \"%s\" unsupported\n",
               kstr, OBJ_nid2ln(pkey->type));
    return 1;
}

int EVP_PKEY_print_public(BIO *out, const EVP_PKEY *pkey,
                          int indent, ASN1_PCTX *pctx)
{
    if (pkey->ameth && pkey->ameth->pub_print)
        return pkey->ameth->pub_print(out, pkey, indent, pctx);

    return unsup_alg(out, pkey, indent, "Public Key");
}

int EVP_PKEY_print_private(BIO *out, const EVP_PKEY *pkey,
                           int indent, ASN1_PCTX *pctx)
{
    if (pkey->ameth && pkey->ameth->priv_print)
        return pkey->ameth->priv_print(out, pkey, indent, pctx);

    return unsup_alg(out, pkey, indent, "Private Key");
}

int EVP_PKEY_print_params(BIO *out, const EVP_PKEY *pkey,
                          int indent, ASN1_PCTX *pctx)
{
    if (pkey->ameth && pkey->ameth->param_print)
        return pkey->ameth->param_print(out, pkey, indent, pctx);
    return unsup_alg(out, pkey, indent, "Parameters");
}

static int evp_pkey_asn1_ctrl(EVP_PKEY *pkey, int op, int arg1, void *arg2)
{
    if (pkey->ameth == NULL || pkey->ameth->pkey_ctrl == NULL)
        return -2;
    return pkey->ameth->pkey_ctrl(pkey, op, arg1, arg2);
}

int EVP_PKEY_get_default_digest_nid(EVP_PKEY *pkey, int *pnid)
{
    return evp_pkey_asn1_ctrl(pkey, ASN1_PKEY_CTRL_DEFAULT_MD_NID, 0, pnid);
}

int EVP_PKEY_supports_digest_nid(EVP_PKEY *pkey, int nid)
{
    int rv, default_nid;

    rv = evp_pkey_asn1_ctrl(pkey, ASN1_PKEY_CTRL_SUPPORTS_MD_NID, nid, NULL);
    if (rv == -2) {
        /*
         * If there is a mandatory default digest and this isn't it, then
         * the answer is 'no'.
         */
        rv = EVP_PKEY_get_default_digest_nid(pkey, &default_nid);
        if (rv == 2)
            return (nid == default_nid);
        /* zero is an error from EVP_PKEY_get_default_digest_nid() */
        if (rv == 0)
            return -1;
    }
    return rv;
}

int EVP_PKEY_set1_tls_encodedpoint(EVP_PKEY *pkey,
                               const unsigned char *pt, size_t ptlen)
{
    if (ptlen > INT_MAX)
        return 0;
    if (evp_pkey_asn1_ctrl(pkey, ASN1_PKEY_CTRL_SET1_TLS_ENCPT, ptlen,
                           (void *)pt) <= 0)
        return 0;
    return 1;
}

size_t EVP_PKEY_get1_tls_encodedpoint(EVP_PKEY *pkey, unsigned char **ppt)
{
    int rv;
    rv = evp_pkey_asn1_ctrl(pkey, ASN1_PKEY_CTRL_GET1_TLS_ENCPT, 0, ppt);
    if (rv <= 0)
        return 0;
    return rv;
}