/*

 * Copyright 2007-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (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 <openssl/x509.h>

#include <openssl/x509v3.h>

#include <openssl/evp.h>

#include <openssl/err.h>

#include "crypto/siphash.h"

#include "siphash_local.h"

#include "crypto/evp.h"

/* SIPHASH pkey context structure */

typedef struct siphash_pkey_ctx_st {

    ASN1_OCTET_STRING ktmp;     /* Temp storage for key */

    SIPHASH ctx;

} SIPHASH_PKEY_CTX;

static int pkey_siphash_init(EVP_PKEY_CTX *ctx)

{

    SIPHASH_PKEY_CTX *pctx;

    if ((pctx = OPENSSL_zalloc(sizeof(*pctx))) == NULL) {

        CRYPTOerr(CRYPTO_F_PKEY_SIPHASH_INIT, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    pctx->ktmp.type = V_ASN1_OCTET_STRING;

    EVP_PKEY_CTX_set_data(ctx, pctx);

    EVP_PKEY_CTX_set0_keygen_info(ctx, NULL, 0);

    return 1;

}

static void pkey_siphash_cleanup(EVP_PKEY_CTX *ctx)

{

    SIPHASH_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    if (pctx != NULL) {

        OPENSSL_clear_free(pctx->ktmp.data, pctx->ktmp.length);

        OPENSSL_clear_free(pctx, sizeof(*pctx));

        EVP_PKEY_CTX_set_data(ctx, NULL);

    }

}

static int pkey_siphash_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)

{

    SIPHASH_PKEY_CTX *sctx, *dctx;

    /* allocate memory for dst->data and a new SIPHASH_CTX in dst->data->ctx */

    if (!pkey_siphash_init(dst))

        return 0;

    sctx = EVP_PKEY_CTX_get_data(src);

    dctx = EVP_PKEY_CTX_get_data(dst);

    if (ASN1_STRING_get0_data(&sctx->ktmp) != NULL &&

        !ASN1_STRING_copy(&dctx->ktmp, &sctx->ktmp)) {

        /* cleanup and free the SIPHASH_PKEY_CTX in dst->data */

        pkey_siphash_cleanup(dst);

        return 0;

    }

    memcpy(&dctx->ctx, &sctx->ctx, sizeof(SIPHASH));

    return 1;

}

static int pkey_siphash_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)

{

    ASN1_OCTET_STRING *key;

    SIPHASH_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    if (ASN1_STRING_get0_data(&pctx->ktmp) == NULL)

        return 0;

    key = ASN1_OCTET_STRING_dup(&pctx->ktmp);

    if (key == NULL)

        return 0;

    return EVP_PKEY_assign_SIPHASH(pkey, key);

}

static int int_update(EVP_MD_CTX *ctx, const void *data, size_t count)

{

    SIPHASH_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(EVP_MD_CTX_pkey_ctx(ctx));

    SipHash_Update(&pctx->ctx, data, count);

    return 1;

}

static int siphash_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)

{

    SIPHASH_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    const unsigned char* key;

    size_t len;

    key = EVP_PKEY_get0_siphash(EVP_PKEY_CTX_get0_pkey(ctx), &len);

    if (key == NULL || len != SIPHASH_KEY_SIZE)

        return 0;

    EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);

    EVP_MD_CTX_set_update_fn(mctx, int_update);

    return SipHash_Init(&pctx->ctx, key, 0, 0);

}

static int siphash_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,

                            EVP_MD_CTX *mctx)

{

    SIPHASH_PKEY_CTX *pctx = ctx->data;

    *siglen = SipHash_hash_size(&pctx->ctx);

    if (sig != NULL)

        return SipHash_Final(&pctx->ctx, sig, *siglen);

    return 1;

}

static int pkey_siphash_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)

{

    SIPHASH_PKEY_CTX *pctx = EVP_PKEY_CTX_get_data(ctx);

    const unsigned char *key;

    size_t len;

    switch (type) {

    case EVP_PKEY_CTRL_MD:

        /* ignore */

        break;

    case EVP_PKEY_CTRL_SET_DIGEST_SIZE:

        return SipHash_set_hash_size(&pctx->ctx, p1);

    case EVP_PKEY_CTRL_SET_MAC_KEY:

    case EVP_PKEY_CTRL_DIGESTINIT:

        if (type == EVP_PKEY_CTRL_SET_MAC_KEY) {

            /* user explicitly setting the key */

            key = p2;

            len = p1;

        } else {

            /* user indirectly setting the key via EVP_DigestSignInit */

            key = EVP_PKEY_get0_siphash(EVP_PKEY_CTX_get0_pkey(ctx), &len);

        }

        if (key == NULL || len != SIPHASH_KEY_SIZE ||

            !ASN1_OCTET_STRING_set(&pctx->ktmp, key, len))

            return 0;

        /* use default rounds (2,4) */

        return SipHash_Init(&pctx->ctx, ASN1_STRING_get0_data(&pctx->ktmp),

                            0, 0);

    default:

        return -2;

    }

    return 1;

}

static int pkey_siphash_ctrl_str(EVP_PKEY_CTX *ctx,

                                  const char *type, const char *value)

{

    if (value == NULL)

        return 0;

    if (strcmp(type, "digestsize") == 0) {

        size_t hash_size = atoi(value);

        return pkey_siphash_ctrl(ctx, EVP_PKEY_CTRL_SET_DIGEST_SIZE, hash_size,

                                 NULL);

    }

    if (strcmp(type, "key") == 0)

        return EVP_PKEY_CTX_str2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);

    if (strcmp(type, "hexkey") == 0)

        return EVP_PKEY_CTX_hex2ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, value);

    return -2;

}

const EVP_PKEY_METHOD siphash_pkey_meth = {

    EVP_PKEY_SIPHASH,

    EVP_PKEY_FLAG_SIGCTX_CUSTOM, /* we don't deal with a separate MD */

    pkey_siphash_init,

    pkey_siphash_copy,

    pkey_siphash_cleanup,

    0, 0,

    0,

    pkey_siphash_keygen,

    0, 0,

    0, 0,

    0, 0,

    siphash_signctx_init,

    siphash_signctx,

    0, 0,

    0, 0,

    0, 0,

    0, 0,

    pkey_siphash_ctrl,

    pkey_siphash_ctrl_str

};