/*

 * Copyright 2018-2022 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 <stdlib.h>

#include <openssl/core_dispatch.h>

#include <openssl/core_names.h>

#include <openssl/params.h>

#include <openssl/evp.h>

#include <openssl/err.h>

#include <openssl/proverr.h>

#include "prov/implementations.h"

#include "prov/provider_ctx.h"

#include "prov/provider_util.h"

#include "prov/providercommon.h"

/*

 * Forward declaration of everything implemented here.  This is not strictly

 * necessary for the compiler, but provides an assurance that the signatures

 * of the functions in the dispatch table are correct.

 */

static OSSL_FUNC_mac_newctx_fn gmac_new;

static OSSL_FUNC_mac_dupctx_fn gmac_dup;

static OSSL_FUNC_mac_freectx_fn gmac_free;

static OSSL_FUNC_mac_gettable_params_fn gmac_gettable_params;

static OSSL_FUNC_mac_get_params_fn gmac_get_params;

static OSSL_FUNC_mac_settable_ctx_params_fn gmac_settable_ctx_params;

static OSSL_FUNC_mac_set_ctx_params_fn gmac_set_ctx_params;

static OSSL_FUNC_mac_init_fn gmac_init;

static OSSL_FUNC_mac_update_fn gmac_update;

static OSSL_FUNC_mac_final_fn gmac_final;

/* local GMAC pkey structure */

struct gmac_data_st {

    void *provctx;

    EVP_CIPHER_CTX *ctx;         /* Cipher context */

    PROV_CIPHER cipher;

};

static void gmac_free(void *vmacctx)

{

    struct gmac_data_st *macctx = vmacctx;

    if (macctx != NULL) {

        EVP_CIPHER_CTX_free(macctx->ctx);

        ossl_prov_cipher_reset(&macctx->cipher);

        OPENSSL_free(macctx);

    }

}

static void *gmac_new(void *provctx)

{

    struct gmac_data_st *macctx;

    if (!ossl_prov_is_running())

        return NULL;

    if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL

        || (macctx->ctx = EVP_CIPHER_CTX_new()) == NULL) {

        gmac_free(macctx);

        return NULL;

    }

    macctx->provctx = provctx;

    return macctx;

}

static void *gmac_dup(void *vsrc)

{

    struct gmac_data_st *src = vsrc;

    struct gmac_data_st *dst;

    if (!ossl_prov_is_running())

        return NULL;

    dst = gmac_new(src->provctx);

    if (dst == NULL)

        return NULL;

    if (!EVP_CIPHER_CTX_copy(dst->ctx, src->ctx)

        || !ossl_prov_cipher_copy(&dst->cipher, &src->cipher)) {

        gmac_free(dst);

        return NULL;

    }

    return dst;

}

static size_t gmac_size(void)

{

    return EVP_GCM_TLS_TAG_LEN;

}

static int gmac_setkey(struct gmac_data_st *macctx,

                       const unsigned char *key, size_t keylen)

{

    EVP_CIPHER_CTX *ctx = macctx->ctx;

    if (keylen != (size_t)EVP_CIPHER_CTX_get_key_length(ctx)) {

        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);

        return 0;

    }

    if (!EVP_EncryptInit_ex(ctx, NULL, NULL, key, NULL))

        return 0;

    return 1;

}

static int gmac_init(void *vmacctx, const unsigned char *key,

                     size_t keylen, const OSSL_PARAM params[])

{

    struct gmac_data_st *macctx = vmacctx;

    if (!ossl_prov_is_running() || !gmac_set_ctx_params(macctx, params))

        return 0;

    if (key != NULL)

        return gmac_setkey(macctx, key, keylen);

    return EVP_EncryptInit_ex(macctx->ctx, NULL, NULL, NULL, NULL);

}

static int gmac_update(void *vmacctx, const unsigned char *data,

                       size_t datalen)

{

    struct gmac_data_st *macctx = vmacctx;

    EVP_CIPHER_CTX *ctx = macctx->ctx;

    int outlen;

    if (datalen == 0)

        return 1;

    while (datalen > INT_MAX) {

        if (!EVP_EncryptUpdate(ctx, NULL, &outlen, data, INT_MAX))

            return 0;

        data += INT_MAX;

        datalen -= INT_MAX;

    }

    return EVP_EncryptUpdate(ctx, NULL, &outlen, data, datalen);

}

static int gmac_final(void *vmacctx, unsigned char *out, size_t *outl,

                      size_t outsize)

{

    OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };

    struct gmac_data_st *macctx = vmacctx;

    int hlen = 0;

    if (!ossl_prov_is_running())

        return 0;

    if (!EVP_EncryptFinal_ex(macctx->ctx, out, &hlen))

        return 0;

    hlen = gmac_size();

    params[0] = OSSL_PARAM_construct_octet_string(OSSL_CIPHER_PARAM_AEAD_TAG,

                                                  out, (size_t)hlen);

    if (!EVP_CIPHER_CTX_get_params(macctx->ctx, params))

        return 0;

    *outl = hlen;

    return 1;

}

static const OSSL_PARAM known_gettable_params[] = {

    OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),

    OSSL_PARAM_END

};

static const OSSL_PARAM *gmac_gettable_params(void *provctx)

{

    return known_gettable_params;

}

static int gmac_get_params(OSSL_PARAM params[])

{

    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)

        return OSSL_PARAM_set_size_t(p, gmac_size());

    return 1;

}

static const OSSL_PARAM known_settable_ctx_params[] = {

    OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_CIPHER, NULL, 0),

    OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),

    OSSL_PARAM_octet_string(OSSL_MAC_PARAM_IV, NULL, 0),

    OSSL_PARAM_END

};

static const OSSL_PARAM *gmac_settable_ctx_params(ossl_unused void *ctx,

                                                  ossl_unused void *provctx)

{

    return known_settable_ctx_params;

}

/*

 * ALL parameters should be set before init().

 */

static int gmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])

{

    struct gmac_data_st *macctx = vmacctx;

    EVP_CIPHER_CTX *ctx = macctx->ctx;

    OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(macctx->provctx);

    const OSSL_PARAM *p;

    if (params == NULL)

        return 1;

    if (ctx == NULL)

        return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_CIPHER)) != NULL) {

        if (!ossl_prov_cipher_load_from_params(&macctx->cipher, params, provctx))

            return 0;

        if (EVP_CIPHER_get_mode(ossl_prov_cipher_cipher(&macctx->cipher))

            != EVP_CIPH_GCM_MODE) {

            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);

            return 0;

        }

        if (!EVP_EncryptInit_ex(ctx, ossl_prov_cipher_cipher(&macctx->cipher),

                                ossl_prov_cipher_engine(&macctx->cipher), NULL,

                                NULL))

            return 0;

    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL)

        if (p->data_type != OSSL_PARAM_OCTET_STRING

                || !gmac_setkey(macctx, p->data, p->data_size))

            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_IV)) != NULL) {

        if (p->data_type != OSSL_PARAM_OCTET_STRING)

            return 0;

        if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN,

                                 p->data_size, NULL) <= 0

            || !EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, p->data))

            return 0;

    }

    return 1;

}

const OSSL_DISPATCH ossl_gmac_functions[] = {

    { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))gmac_new },

    { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))gmac_dup },

    { OSSL_FUNC_MAC_FREECTX, (void (*)(void))gmac_free },

    { OSSL_FUNC_MAC_INIT, (void (*)(void))gmac_init },

    { OSSL_FUNC_MAC_UPDATE, (void (*)(void))gmac_update },

    { OSSL_FUNC_MAC_FINAL, (void (*)(void))gmac_final },

    { OSSL_FUNC_MAC_GETTABLE_PARAMS, (void (*)(void))gmac_gettable_params },

    { OSSL_FUNC_MAC_GET_PARAMS, (void (*)(void))gmac_get_params },

    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,

      (void (*)(void))gmac_settable_ctx_params },

    { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))gmac_set_ctx_params },

    { 0, NULL }

};