/* $OpenBSD: eng_openssl.c,v 1.15 2022/01/09 23:55:31 tb Exp $ */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 1999-2001 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECDH support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

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

#include <openssl/opensslconf.h>

#include <openssl/crypto.h>
#include <openssl/dso.h>
#include <openssl/engine.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/rand.h>

#ifndef OPENSSL_NO_DH
#include <openssl/dh.h>
#endif
#ifndef OPENSSL_NO_DSA
#include <openssl/dsa.h>
#endif
#ifndef OPENSSL_NO_RSA
#include <openssl/rsa.h>
#endif

#include "evp_locl.h"

/* This testing gunk is implemented (and explained) lower down. It also assumes
 * the application explicitly calls "ENGINE_load_openssl()" because this is no
 * longer automatic in ENGINE_load_builtin_engines(). */
#define TEST_ENG_OPENSSL_RC4
#define TEST_ENG_OPENSSL_PKEY
/* #define TEST_ENG_OPENSSL_RC4_OTHERS */
#define TEST_ENG_OPENSSL_RC4_P_INIT
/* #define TEST_ENG_OPENSSL_RC4_P_CIPHER */
#define TEST_ENG_OPENSSL_SHA
/* #define TEST_ENG_OPENSSL_SHA_OTHERS */
/* #define TEST_ENG_OPENSSL_SHA_P_INIT */
/* #define TEST_ENG_OPENSSL_SHA_P_UPDATE */
/* #define TEST_ENG_OPENSSL_SHA_P_FINAL */

/* Now check what of those algorithms are actually enabled */
#ifdef OPENSSL_NO_RC4
#undef TEST_ENG_OPENSSL_RC4
#undef TEST_ENG_OPENSSL_RC4_OTHERS
#undef TEST_ENG_OPENSSL_RC4_P_INIT
#undef TEST_ENG_OPENSSL_RC4_P_CIPHER
#endif
#if defined(OPENSSL_NO_SHA) || defined(OPENSSL_NO_SHA1)
#undef TEST_ENG_OPENSSL_SHA
#undef TEST_ENG_OPENSSL_SHA_OTHERS
#undef TEST_ENG_OPENSSL_SHA_P_INIT
#undef TEST_ENG_OPENSSL_SHA_P_UPDATE
#undef TEST_ENG_OPENSSL_SHA_P_FINAL
#endif

#ifdef TEST_ENG_OPENSSL_RC4
static int openssl_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
    const int **nids, int nid);
#endif
#ifdef TEST_ENG_OPENSSL_SHA
static int openssl_digests(ENGINE *e, const EVP_MD **digest,
    const int **nids, int nid);
#endif

#ifdef TEST_ENG_OPENSSL_PKEY
static EVP_PKEY *openssl_load_privkey(ENGINE *eng, const char *key_id,
    UI_METHOD *ui_method, void *callback_data);
#endif

/* The constants used when creating the ENGINE */
static const char *engine_openssl_id = "openssl";
static const char *engine_openssl_name = "Software engine support";

/* This internal function is used by ENGINE_openssl() and possibly by the
 * "dynamic" ENGINE support too */
static int
bind_helper(ENGINE *e)
{
        if (!ENGINE_set_id(e, engine_openssl_id) ||
            !ENGINE_set_name(e, engine_openssl_name)
#ifndef TEST_ENG_OPENSSL_NO_ALGORITHMS
#ifndef OPENSSL_NO_RSA
            || !ENGINE_set_RSA(e, RSA_get_default_method())
#endif
#ifndef OPENSSL_NO_DSA
            || !ENGINE_set_DSA(e, DSA_get_default_method())
#endif
#ifndef OPENSSL_NO_ECDH
            || !ENGINE_set_ECDH(e, ECDH_OpenSSL())
#endif
#ifndef OPENSSL_NO_ECDSA
            || !ENGINE_set_ECDSA(e, ECDSA_OpenSSL())
#endif
#ifndef OPENSSL_NO_DH
            || !ENGINE_set_DH(e, DH_get_default_method())
#endif
            || !ENGINE_set_RAND(e, RAND_SSLeay())
#ifdef TEST_ENG_OPENSSL_RC4
            || !ENGINE_set_ciphers(e, openssl_ciphers)
#endif
#ifdef TEST_ENG_OPENSSL_SHA
            || !ENGINE_set_digests(e, openssl_digests)
#endif
#endif
#ifdef TEST_ENG_OPENSSL_PKEY
            || !ENGINE_set_load_privkey_function(e, openssl_load_privkey)
#endif
                )
                return 0;
        /* If we add errors to this ENGINE, ensure the error handling is setup here */
        /* openssl_load_error_strings(); */
        return 1;
}

static ENGINE *
engine_openssl(void)
{
        ENGINE *ret = ENGINE_new();

        if (ret == NULL)
                return NULL;
        if (!bind_helper(ret)) {
                ENGINE_free(ret);
                return NULL;
        }
        return ret;
}

void
ENGINE_load_openssl(void)
{
        ENGINE *toadd = engine_openssl();

        if (toadd == NULL)
                return;
        (void) ENGINE_add(toadd);
        /* If the "add" worked, it gets a structural reference. So either way,
         * we release our just-created reference. */
        ENGINE_free(toadd);
        ERR_clear_error();
}

/* This stuff is needed if this ENGINE is being compiled into a self-contained
 * shared-library. */
#ifdef ENGINE_DYNAMIC_SUPPORT
static int
bind_fn(ENGINE *e, const char *id)
{
        if (id && (strcmp(id, engine_openssl_id) != 0))
                return 0;
        if (!bind_helper(e))
                return 0;
        return 1;
}
IMPLEMENT_DYNAMIC_CHECK_FN()
IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
#endif /* ENGINE_DYNAMIC_SUPPORT */

#ifdef TEST_ENG_OPENSSL_RC4
/* This section of code compiles an "alternative implementation" of two modes of
 * RC4 into this ENGINE. The result is that EVP_CIPHER operation for "rc4"
 * should under normal circumstances go via this support rather than the default
 * EVP support. There are other symbols to tweak the testing;
 *    TEST_ENC_OPENSSL_RC4_OTHERS - print a one line message to stderr each time
 *        we're asked for a cipher we don't support (should not happen).
 *    TEST_ENG_OPENSSL_RC4_P_INIT - print a one line message to stderr each time
 *        the "init_key" handler is called.
 *    TEST_ENG_OPENSSL_RC4_P_CIPHER - ditto for the "cipher" handler.
 */
#include <openssl/rc4.h>
#define TEST_RC4_KEY_SIZE               16
static int test_cipher_nids[] = {NID_rc4, NID_rc4_40};
static int test_cipher_nids_number = 2;

typedef struct {
        unsigned char key[TEST_RC4_KEY_SIZE];
        RC4_KEY ks;
} TEST_RC4_KEY;

#define test(ctx) ((TEST_RC4_KEY *)(ctx)->cipher_data)
static int
test_rc4_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
#ifdef TEST_ENG_OPENSSL_RC4_P_INIT
        fprintf(stderr, "(TEST_ENG_OPENSSL_RC4) test_init_key() called\n");
#endif
        memcpy(&test(ctx)->key[0], key, EVP_CIPHER_CTX_key_length(ctx));
        RC4_set_key(&test(ctx)->ks, EVP_CIPHER_CTX_key_length(ctx),
            test(ctx)->key);
        return 1;
}

static int
test_rc4_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl)
{
#ifdef TEST_ENG_OPENSSL_RC4_P_CIPHER
        fprintf(stderr, "(TEST_ENG_OPENSSL_RC4) test_cipher() called\n");
#endif
        RC4(&test(ctx)->ks, inl, in, out);
        return 1;
}

static const EVP_CIPHER test_r4_cipher = {
        NID_rc4,
        1, TEST_RC4_KEY_SIZE, 0,
        EVP_CIPH_VARIABLE_LENGTH,
        test_rc4_init_key,
        test_rc4_cipher,
        NULL,
        sizeof(TEST_RC4_KEY),
        NULL,
        NULL,
        NULL,
        NULL
};

static const EVP_CIPHER test_r4_40_cipher = {
        NID_rc4_40,
        1,5 /* 40 bit */,0,
        EVP_CIPH_VARIABLE_LENGTH,
        test_rc4_init_key,
        test_rc4_cipher,
        NULL,
        sizeof(TEST_RC4_KEY),
        NULL,
        NULL,
        NULL,
        NULL
};

static int
openssl_ciphers(ENGINE *e, const EVP_CIPHER **cipher, const int **nids, int nid)
{
        if (!cipher) {
                /* We are returning a list of supported nids */
                *nids = test_cipher_nids;
                return test_cipher_nids_number;
        }
        /* We are being asked for a specific cipher */
        if (nid == NID_rc4)
                *cipher = &test_r4_cipher;
        else if (nid == NID_rc4_40)
                *cipher = &test_r4_40_cipher;
        else {
#ifdef TEST_ENG_OPENSSL_RC4_OTHERS
                fprintf(stderr, "(TEST_ENG_OPENSSL_RC4) returning NULL for "
                    "nid %d\n", nid);
#endif
                *cipher = NULL;
                return 0;
        }
        return 1;
}
#endif

#ifdef TEST_ENG_OPENSSL_SHA
/* Much the same sort of comment as for TEST_ENG_OPENSSL_RC4 */
#include <openssl/sha.h>
static int test_digest_nids[] = {NID_sha1};
static int test_digest_nids_number = 1;

static int
test_sha1_init(EVP_MD_CTX *ctx)
{
#ifdef TEST_ENG_OPENSSL_SHA_P_INIT
        fprintf(stderr, "(TEST_ENG_OPENSSL_SHA) test_sha1_init() called\n");
#endif
        return SHA1_Init(ctx->md_data);
}

static int
test_sha1_update(EVP_MD_CTX *ctx, const void *data, size_t count)
{
#ifdef TEST_ENG_OPENSSL_SHA_P_UPDATE
        fprintf(stderr, "(TEST_ENG_OPENSSL_SHA) test_sha1_update() called\n");
#endif
        return SHA1_Update(ctx->md_data, data, count);
}

static int
test_sha1_final(EVP_MD_CTX *ctx, unsigned char *md)
{
#ifdef TEST_ENG_OPENSSL_SHA_P_FINAL
        fprintf(stderr, "(TEST_ENG_OPENSSL_SHA) test_sha1_final() called\n");
#endif
        return SHA1_Final(md, ctx->md_data);
}

static const EVP_MD test_sha_md = {
        .type = NID_sha1,
        .pkey_type = NID_sha1WithRSAEncryption,
        .md_size = SHA_DIGEST_LENGTH,
        .flags = 0,
        .init = test_sha1_init,
        .update = test_sha1_update,
        .final = test_sha1_final,
        .copy = NULL,
        .cleanup = NULL,
        .block_size = SHA_CBLOCK,
        .ctx_size = sizeof(EVP_MD *) + sizeof(SHA_CTX),
};

static int
openssl_digests(ENGINE *e, const EVP_MD **digest, const int **nids, int nid)
{
        if (!digest) {
                /* We are returning a list of supported nids */
                *nids = test_digest_nids;
                return test_digest_nids_number;
        }
        /* We are being asked for a specific digest */
        if (nid == NID_sha1)
                *digest = &test_sha_md;
        else {
#ifdef TEST_ENG_OPENSSL_SHA_OTHERS
                fprintf(stderr, "(TEST_ENG_OPENSSL_SHA) returning NULL for "
                    "nid %d\n", nid);
#endif
                *digest = NULL;
                return 0;
        }
        return 1;
}
#endif

#ifdef TEST_ENG_OPENSSL_PKEY
static EVP_PKEY *
openssl_load_privkey(ENGINE *eng, const char *key_id, UI_METHOD *ui_method,
    void *callback_data)
{
        BIO *in;
        EVP_PKEY *key;

        fprintf(stderr, "(TEST_ENG_OPENSSL_PKEY)Loading Private key %s\n",
            key_id);
        in = BIO_new_file(key_id, "r");
        if (!in)
                return NULL;
        key = PEM_read_bio_PrivateKey(in, NULL, 0, NULL);
        BIO_free(in);
        return key;
}
#endif