/* $OpenBSD: eng_openssl.c,v 1.16 2022/11/26 16:08:52 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_local.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
