/*
 * Copyright 2020 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 <assert.h>
#include <openssl/core_numbers.h>
#include <openssl/core_names.h>
#include "crypto/ecx.h"
#include "prov/implementations.h"
#include "prov/providercommon.h"
#include "internal/param_build_set.h"

static OSSL_OP_keymgmt_new_fn x25519_new_key;
static OSSL_OP_keymgmt_new_fn x448_new_key;
static OSSL_OP_keymgmt_new_fn ed25519_new_key;
static OSSL_OP_keymgmt_new_fn ed448_new_key;
static OSSL_OP_keymgmt_get_params_fn x25519_get_params;
static OSSL_OP_keymgmt_get_params_fn x448_get_params;
static OSSL_OP_keymgmt_get_params_fn ed25519_get_params;
static OSSL_OP_keymgmt_get_params_fn ed448_get_params;
static OSSL_OP_keymgmt_gettable_params_fn ecx_gettable_params;
static OSSL_OP_keymgmt_has_fn ecx_has;
static OSSL_OP_keymgmt_import_fn ecx_import;
static OSSL_OP_keymgmt_import_types_fn ecx_imexport_types;
static OSSL_OP_keymgmt_export_fn ecx_export;
static OSSL_OP_keymgmt_export_types_fn ecx_imexport_types;

#define ECX_POSSIBLE_SELECTIONS (OSSL_KEYMGMT_SELECT_KEYPAIR)

static void *x25519_new_key(void *provctx)
{
    return ecx_key_new(ECX_KEY_TYPE_X25519, 0);
}

static void *x448_new_key(void *provctx)
{
    return ecx_key_new(ECX_KEY_TYPE_X448, 0);
}

static void *ed25519_new_key(void *provctx)
{
    return ecx_key_new(ECX_KEY_TYPE_ED25519, 0);
}

static void *ed448_new_key(void *provctx)
{
    return ecx_key_new(ECX_KEY_TYPE_ED448, 0);
}

static int ecx_has(void *keydata, int selection)
{
    ECX_KEY *key = keydata;
    int ok = 0;

    if (key != NULL) {
        if ((selection & ECX_POSSIBLE_SELECTIONS) != 0)
            ok = 1;

        if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
            ok = ok && key->haspubkey;

        if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
            ok = ok && key->privkey != NULL;
    }
    return ok;
}

static int ecx_import(void *keydata, int selection, const OSSL_PARAM params[])
{
    ECX_KEY *key = keydata;
    int ok = 1;
    int include_private = 0;

    if (key == NULL)
        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) == 0)
        return 0;

    include_private = ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0);
    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)
        ok = ok && ecx_key_fromdata(key, params, include_private);

    return ok;
}

static int key_to_params(ECX_KEY *key, OSSL_PARAM_BLD *tmpl,
                         OSSL_PARAM params[])
{
    if (key == NULL)
        return 0;

    if (!ossl_param_build_set_octet_string(tmpl, params,
                                           OSSL_PKEY_PARAM_PUB_KEY,
                                           key->pubkey, key->keylen))
        return 0;

    if (key->privkey != NULL
        && !ossl_param_build_set_octet_string(tmpl, params,
                                              OSSL_PKEY_PARAM_PRIV_KEY,
                                              key->privkey, key->keylen))
        return 0;

    return 1;
}

static int ecx_export(void *keydata, int selection, OSSL_CALLBACK *param_cb,
                      void *cbarg)
{
    ECX_KEY *key = keydata;
    OSSL_PARAM_BLD *tmpl;
    OSSL_PARAM *params = NULL;
    int ret = 0;

    if (key == NULL)
        return 0;

    tmpl = OSSL_PARAM_BLD_new();
    if (tmpl == NULL)
        return 0;

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0
         && !key_to_params(key, tmpl, NULL))
        goto err;

    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0
         && !key_to_params(key, tmpl, NULL))
        goto err;

    params = OSSL_PARAM_BLD_to_param(tmpl);
    if (params == NULL)
        goto err;

    ret = param_cb(params, cbarg);
    OSSL_PARAM_BLD_free_params(params);
err:
    OSSL_PARAM_BLD_free(tmpl);
    return ret;
}

#define ECX_KEY_TYPES()                                                        \
OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_PUB_KEY, NULL, 0),                     \
OSSL_PARAM_octet_string(OSSL_PKEY_PARAM_PRIV_KEY, NULL, 0)

static const OSSL_PARAM ecx_key_types[] = {
    ECX_KEY_TYPES(),
    OSSL_PARAM_END
};
static const OSSL_PARAM *ecx_imexport_types(int selection)
{
    if ((selection & OSSL_KEYMGMT_SELECT_KEYPAIR) != 0)
        return ecx_key_types;
    return NULL;
}

static int ecx_get_params(void *key, OSSL_PARAM params[], int bits, int secbits,
                          int size)
{
    ECX_KEY *ecx = key;
    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_BITS)) != NULL
        && !OSSL_PARAM_set_int(p, bits))
        return 0;
    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_SECURITY_BITS)) != NULL
        && !OSSL_PARAM_set_int(p, secbits))
        return 0;
    if ((p = OSSL_PARAM_locate(params, OSSL_PKEY_PARAM_MAX_SIZE)) != NULL
        && !OSSL_PARAM_set_int(p, size))
        return 0;
    return key_to_params(ecx, NULL, params);
}

static int x25519_get_params(void *key, OSSL_PARAM params[])
{
    return ecx_get_params(key, params, X25519_BITS, X25519_SECURITY_BITS,
                          X25519_KEYLEN);
}

static int x448_get_params(void *key, OSSL_PARAM params[])
{
    return ecx_get_params(key, params, X448_BITS, X448_SECURITY_BITS,
                          X448_KEYLEN);
}

static int ed25519_get_params(void *key, OSSL_PARAM params[])
{
    return ecx_get_params(key, params, ED25519_BITS, ED25519_SECURITY_BITS,
                          ED25519_KEYLEN);
}

static int ed448_get_params(void *key, OSSL_PARAM params[])
{
    return ecx_get_params(key, params, ED448_BITS, ED448_SECURITY_BITS,
                          ED448_KEYLEN);
}

static const OSSL_PARAM ecx_params[] = {
    OSSL_PARAM_int(OSSL_PKEY_PARAM_BITS, NULL),
    OSSL_PARAM_int(OSSL_PKEY_PARAM_SECURITY_BITS, NULL),
    OSSL_PARAM_int(OSSL_PKEY_PARAM_MAX_SIZE, NULL),
    ECX_KEY_TYPES(),
    OSSL_PARAM_END
};

static const OSSL_PARAM *ecx_gettable_params(void)
{
    return ecx_params;
}

#define MAKE_KEYMGMT_FUNCTIONS(alg) \
    const OSSL_DISPATCH alg##_keymgmt_functions[] = { \
        { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))alg##_new_key }, \
        { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))ecx_key_free }, \
        { OSSL_FUNC_KEYMGMT_GET_PARAMS, (void (*) (void))alg##_get_params }, \
        { OSSL_FUNC_KEYMGMT_GETTABLE_PARAMS, (void (*) (void))ecx_gettable_params }, \
        { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))ecx_has }, \
        { OSSL_FUNC_KEYMGMT_IMPORT, (void (*)(void))ecx_import }, \
        { OSSL_FUNC_KEYMGMT_IMPORT_TYPES, (void (*)(void))ecx_imexport_types }, \
        { OSSL_FUNC_KEYMGMT_EXPORT, (void (*)(void))ecx_export }, \
        { OSSL_FUNC_KEYMGMT_EXPORT_TYPES, (void (*)(void))ecx_imexport_types }, \
        { 0, NULL } \
    };

MAKE_KEYMGMT_FUNCTIONS(x25519)
MAKE_KEYMGMT_FUNCTIONS(x448)
MAKE_KEYMGMT_FUNCTIONS(ed25519)
MAKE_KEYMGMT_FUNCTIONS(ed448)
