/*

 * 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 <string.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 "crypto/siphash.h"

#include "prov/implementations.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 siphash_new;

static OSSL_FUNC_mac_dupctx_fn siphash_dup;

static OSSL_FUNC_mac_freectx_fn siphash_free;

static OSSL_FUNC_mac_gettable_ctx_params_fn siphash_gettable_ctx_params;

static OSSL_FUNC_mac_get_ctx_params_fn siphash_get_ctx_params;

static OSSL_FUNC_mac_settable_ctx_params_fn siphash_settable_ctx_params;

static OSSL_FUNC_mac_set_ctx_params_fn siphash_set_params;

static OSSL_FUNC_mac_init_fn siphash_init;

static OSSL_FUNC_mac_update_fn siphash_update;

static OSSL_FUNC_mac_final_fn siphash_final;

struct siphash_data_st {

    void *provctx;

    SIPHASH siphash;             /* Siphash data */

    SIPHASH sipcopy;             /* Siphash data copy for reinitialization */

    unsigned int crounds, drounds;

};

static unsigned int crounds(struct siphash_data_st *ctx)

{

    return ctx->crounds != 0 ? ctx->crounds : SIPHASH_C_ROUNDS;

}

static unsigned int drounds(struct siphash_data_st *ctx)

{

    return ctx->drounds != 0 ? ctx->drounds : SIPHASH_D_ROUNDS;

}

static void *siphash_new(void *provctx)

{

    struct siphash_data_st *ctx;

    if (!ossl_prov_is_running())

        return NULL;

    ctx = OPENSSL_zalloc(sizeof(*ctx));

    if (ctx != NULL)

        ctx->provctx = provctx;

    return ctx;

}

static void siphash_free(void *vmacctx)

{

    OPENSSL_free(vmacctx);

}

static void *siphash_dup(void *vsrc)

{

    struct siphash_data_st *ssrc = vsrc;

    struct siphash_data_st *sdst;

    if (!ossl_prov_is_running())

        return NULL;

    sdst = OPENSSL_malloc(sizeof(*sdst));

    if (sdst == NULL)

        return NULL;

    *sdst = *ssrc;

    return sdst;

}

static size_t siphash_size(void *vmacctx)

{

    struct siphash_data_st *ctx = vmacctx;

    return SipHash_hash_size(&ctx->siphash);

}

static int siphash_setkey(struct siphash_data_st *ctx,

                          const unsigned char *key, size_t keylen)

{

    int ret;

    if (keylen != SIPHASH_KEY_SIZE)

        return 0;

    ret = SipHash_Init(&ctx->siphash, key, crounds(ctx), drounds(ctx));

    if (ret)

        ctx->sipcopy = ctx->siphash;

    return ret;

}

static int siphash_init(void *vmacctx, const unsigned char *key, size_t keylen,

                        const OSSL_PARAM params[])

{

    struct siphash_data_st *ctx = vmacctx;

    if (!ossl_prov_is_running() || !siphash_set_params(ctx, params))

        return 0;

    /*

     * Without a key, there is not much to do here,

     * The actual initialization happens through controls.

     */

    if (key == NULL) {

        ctx->siphash = ctx->sipcopy;

        return 1;

    }

    return siphash_setkey(ctx, key, keylen);

}

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

                          size_t datalen)

{

    struct siphash_data_st *ctx = vmacctx;

    if (datalen == 0)

        return 1;

    SipHash_Update(&ctx->siphash, data, datalen);

    return 1;

}

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

                         size_t outsize)

{

    struct siphash_data_st *ctx = vmacctx;

    size_t hlen = siphash_size(ctx);

    if (!ossl_prov_is_running() || outsize < hlen)

        return 0;

    *outl = hlen;

    return SipHash_Final(&ctx->siphash, out, hlen);

}

static const OSSL_PARAM *siphash_gettable_ctx_params(ossl_unused void *ctx,

                                                     ossl_unused void *provctx)

{

    static const OSSL_PARAM known_gettable_ctx_params[] = {

        OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),

        OSSL_PARAM_uint(OSSL_MAC_PARAM_C_ROUNDS, NULL),

        OSSL_PARAM_uint(OSSL_MAC_PARAM_D_ROUNDS, NULL),

        OSSL_PARAM_END

    };

    return known_gettable_ctx_params;

}

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

{

    struct siphash_data_st *ctx = vmacctx;

    OSSL_PARAM *p;

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

        && !OSSL_PARAM_set_size_t(p, siphash_size(vmacctx)))

        return 0;

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

        && !OSSL_PARAM_set_uint(p, crounds(ctx)))

        return 0;

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

        && !OSSL_PARAM_set_uint(p, drounds(ctx)))

        return 0;

    return 1;

}

static const OSSL_PARAM *siphash_settable_ctx_params(ossl_unused void *ctx,

                                                     void *provctx)

{

    static const OSSL_PARAM known_settable_ctx_params[] = {

        OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),

        OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),

        OSSL_PARAM_uint(OSSL_MAC_PARAM_C_ROUNDS, NULL),

        OSSL_PARAM_uint(OSSL_MAC_PARAM_D_ROUNDS, NULL),

        OSSL_PARAM_END

    };

    return known_settable_ctx_params;

}

static int siphash_set_params(void *vmacctx, const OSSL_PARAM *params)

{

    struct siphash_data_st *ctx = vmacctx;

    const OSSL_PARAM *p = NULL;

    size_t size;

    if (params == NULL)

        return 1;

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

        if (!OSSL_PARAM_get_size_t(p, &size)

            || !SipHash_set_hash_size(&ctx->siphash, size)

            || !SipHash_set_hash_size(&ctx->sipcopy, size))

            return 0;

    }

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

            && !OSSL_PARAM_get_uint(p, &ctx->crounds))

        return 0;

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

            && !OSSL_PARAM_get_uint(p, &ctx->drounds))

        return 0;

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

        if (p->data_type != OSSL_PARAM_OCTET_STRING

            || !siphash_setkey(ctx, p->data, p->data_size))

            return 0;

    return 1;

}

const OSSL_DISPATCH ossl_siphash_functions[] = {

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

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

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

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

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

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

    { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,

      (void (*)(void))siphash_gettable_ctx_params },

    { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))siphash_get_ctx_params },

    { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,

      (void (*)(void))siphash_settable_ctx_params },

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

    { 0, NULL }

};