/* $OpenBSD: hm_pmeth.c,v 1.17 2023/12/28 22:00:56 tb Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 2007.
 */
/* ====================================================================
 * Copyright (c) 2007 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <string.h>

#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>

#include "evp_local.h"
#include "hmac_local.h"

/* HMAC pkey context structure */

typedef struct {
        const EVP_MD *md;       /* MD for HMAC use */
        ASN1_OCTET_STRING ktmp; /* Temp storage for key */
        HMAC_CTX ctx;
} HMAC_PKEY_CTX;

static int
pkey_hmac_init(EVP_PKEY_CTX *ctx)
{
        HMAC_PKEY_CTX *hctx;

        if ((hctx = calloc(1, sizeof(HMAC_PKEY_CTX))) == NULL)
                return 0;

        hctx->ktmp.type = V_ASN1_OCTET_STRING;
        HMAC_CTX_init(&hctx->ctx);

        ctx->data = hctx;
        ctx->keygen_info_count = 0;

        return 1;
}

static int
pkey_hmac_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
{
        HMAC_PKEY_CTX *sctx, *dctx;

        if (!pkey_hmac_init(dst))
                return 0;
        sctx = src->data;
        dctx = dst->data;
        dctx->md = sctx->md;
        HMAC_CTX_init(&dctx->ctx);
        if (!HMAC_CTX_copy(&dctx->ctx, &sctx->ctx))
                return 0;
        if (sctx->ktmp.data) {
                if (!ASN1_OCTET_STRING_set(&dctx->ktmp, sctx->ktmp.data,
                    sctx->ktmp.length))
                        return 0;
        }
        return 1;
}

static void
pkey_hmac_cleanup(EVP_PKEY_CTX *ctx)
{
        HMAC_PKEY_CTX *hctx;

        if ((hctx = ctx->data) == NULL)
                return;

        HMAC_CTX_cleanup(&hctx->ctx);
        freezero(hctx->ktmp.data, hctx->ktmp.length);
        free(hctx);
}

static int
pkey_hmac_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{
        ASN1_OCTET_STRING *hkey = NULL;
        HMAC_PKEY_CTX *hctx = ctx->data;
        int ret = 0;

        if (hctx->ktmp.data == NULL)
                goto err;
        if ((hkey = ASN1_OCTET_STRING_dup(&hctx->ktmp)) == NULL)
                goto err;
        if (!EVP_PKEY_assign(pkey, EVP_PKEY_HMAC, hkey))
                goto err;
        hkey = NULL;

        ret = 1;

 err:
        ASN1_OCTET_STRING_free(hkey);

        return ret;
}

static int
int_update(EVP_MD_CTX *ctx, const void *data, size_t count)
{
        HMAC_PKEY_CTX *hctx = ctx->pctx->data;

        if (!HMAC_Update(&hctx->ctx, data, count))
                return 0;
        return 1;
}

static int
hmac_signctx_init(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
{
        HMAC_PKEY_CTX *hctx = ctx->data;

        HMAC_CTX_set_flags(&hctx->ctx, mctx->flags & ~EVP_MD_CTX_FLAG_NO_INIT);
        EVP_MD_CTX_set_flags(mctx, EVP_MD_CTX_FLAG_NO_INIT);
        mctx->update = int_update;
        return 1;
}

static int
hmac_signctx(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
    EVP_MD_CTX *mctx)
{
        unsigned int hlen;
        HMAC_PKEY_CTX *hctx = ctx->data;
        int l = EVP_MD_CTX_size(mctx);

        if (l < 0)
                return 0;
        *siglen = l;
        if (!sig)
                return 1;

        if (!HMAC_Final(&hctx->ctx, sig, &hlen))
                return 0;
        *siglen = (size_t)hlen;
        return 1;
}

static int
pkey_hmac_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
        HMAC_PKEY_CTX *hctx = ctx->data;
        ASN1_OCTET_STRING *key;

        switch (type) {
        case EVP_PKEY_CTRL_SET_MAC_KEY:
                if ((!p2 && p1 > 0) || (p1 < -1))
                        return 0;
                if (!ASN1_OCTET_STRING_set(&hctx->ktmp, p2, p1))
                        return 0;
                break;

        case EVP_PKEY_CTRL_MD:
                hctx->md = p2;
                break;

        case EVP_PKEY_CTRL_DIGESTINIT:
                key = ctx->pkey->pkey.ptr;
                if (!HMAC_Init_ex(&hctx->ctx, key->data, key->length, hctx->md,
                    NULL))
                        return 0;
                break;

        default:
                return -2;
        }
        return 1;
}

static int
pkey_hmac_ctrl_str(EVP_PKEY_CTX *ctx, const char *type, const char *value)
{
        if (!value)
                return 0;
        if (!strcmp(type, "key")) {
                void *p = (void *)value;
                return pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, -1, p);
        }
        if (!strcmp(type, "hexkey")) {
                unsigned char *key;
                int r;
                long keylen;
                key = string_to_hex(value, &keylen);
                if (!key)
                        return 0;
                r = pkey_hmac_ctrl(ctx, EVP_PKEY_CTRL_SET_MAC_KEY, keylen, key);
                free(key);
                return r;
        }
        return -2;
}

const EVP_PKEY_METHOD hmac_pkey_meth = {
        .pkey_id = EVP_PKEY_HMAC,

        .init = pkey_hmac_init,
        .copy = pkey_hmac_copy,
        .cleanup = pkey_hmac_cleanup,

        .keygen = pkey_hmac_keygen,

        .signctx_init = hmac_signctx_init,
        .signctx = hmac_signctx,

        .ctrl = pkey_hmac_ctrl,
        .ctrl_str = pkey_hmac_ctrl_str
};