GmSSL/crypto/evp/e_sms4_xts.c

/* ====================================================================
 * Copyright (c) 2014 - 2017 The GmSSL Project.  All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
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 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the GmSSL Project.
 *    (http://gmssl.org/)"
 *
 * 4. The name "GmSSL Project" must not be used to endorse or promote
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 *    permission. For written permission, please contact
 *    guanzhi1980@gmail.com.
 *
 * 5. Products derived from this software may not be called "GmSSL"
 *    nor may "GmSSL" appear in their names without prior written
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 *    acknowledgment:
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 *
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 */
 /*
 * Copyright 2001-2016 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 <openssl/evp.h>
#include <openssl/crypto.h>
#include <openssl/objects.h>
#include "evp_locl.h"
# include "internal/evp_int.h"
#include "../modes/modes_lcl.h"

#ifndef OPENSSL_NO_SMS4
# include <openssl/sms4.h>

typedef struct {
    union {
        double align;
        sms4_key_t ks;
    } ks1, ks2;                 /* SMS4 key schedules to use */
    XTS128_CONTEXT xts;
    void (*stream) (const unsigned char *in,
                    unsigned char *out, size_t length,
                    const sms4_key_t *key1, const sms4_key_t *key2,
                    const unsigned char iv[16]);
} EVP_SMS4_XTS_CTX;

static int sms4_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
    EVP_SMS4_XTS_CTX *xctx = EVP_C_DATA(EVP_SMS4_XTS_CTX,c);
    if (type == EVP_CTRL_COPY) {
        EVP_CIPHER_CTX *out = ptr;
        EVP_SMS4_XTS_CTX *xctx_out = EVP_C_DATA(EVP_SMS4_XTS_CTX,out);
        if (xctx->xts.key1) {
            if (xctx->xts.key1 != &xctx->ks1)
                return 0;
            xctx_out->xts.key1 = &xctx_out->ks1;
        }
        if (xctx->xts.key2) {
            if (xctx->xts.key2 != &xctx->ks2)
                return 0;
            xctx_out->xts.key2 = &xctx_out->ks2;
        }
        return 1;
    } else if (type != EVP_CTRL_INIT)
        return -1;
    /* key1 and key2 are used as an indicator both key and IV are set */
    xctx->xts.key1 = NULL;
    xctx->xts.key2 = NULL;
    return 1;
}

static int sms4_xts_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
                             const unsigned char *iv, int enc)
{
    EVP_SMS4_XTS_CTX *xctx = EVP_C_DATA(EVP_SMS4_XTS_CTX,ctx);
    if (!iv && !key)
        return 1;

    if (key)
        do {
            xctx->stream = NULL;
            /* key_len is two SMS4 keys */
            (void)0;        /* terminate potentially open 'else' */

            if (enc) {
                sms4_set_encrypt_key(&xctx->ks1.ks, key);
                xctx->xts.block1 = (block128_f)sms4_encrypt;
            } else {
                sms4_set_decrypt_key(&xctx->ks1.ks, key);
                xctx->xts.block1 = (block128_f)sms4_encrypt;
            }

            sms4_set_encrypt_key(&xctx->ks2.ks, key + EVP_CIPHER_CTX_key_length(ctx)/2);
            xctx->xts.block2 = (block128_f)sms4_encrypt;

            xctx->xts.key1 = &xctx->ks1;
        } while (0);

    if (iv) {
        xctx->xts.key2 = &xctx->ks2;
        memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), iv, 16);
    }

    return 1;
}

static int sms4_xts_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
                           const unsigned char *in, size_t len)
{
    EVP_SMS4_XTS_CTX *xctx = EVP_C_DATA(EVP_SMS4_XTS_CTX,ctx);
    if (!xctx->xts.key1 || !xctx->xts.key2)
        return 0;
    if (!out || !in || len < SMS4_BLOCK_SIZE)
        return 0;
    if (xctx->stream)
        (*xctx->stream) (in, out, len,
                         xctx->xts.key1, xctx->xts.key2,
                         EVP_CIPHER_CTX_iv_noconst(ctx));
    else if (CRYPTO_xts128_encrypt(&xctx->xts, EVP_CIPHER_CTX_iv_noconst(ctx),
                                   in, out, len,
                                   EVP_CIPHER_CTX_encrypting(ctx)))
        return 0;
    return 1;
}

#define SMS4_XTS_BLOCK_SIZE	1

#define SMS4_XTS_FLAGS   (EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CUSTOM_IV \
                         | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT \
                         | EVP_CIPH_CUSTOM_COPY)

static const EVP_CIPHER sms4_xts = {
	NID_sms4_xts,
	SMS4_XTS_BLOCK_SIZE,
	SMS4_KEY_LENGTH,
	SMS4_IV_LENGTH,
	SMS4_XTS_FLAGS,
	sms4_xts_init_key,
	sms4_xts_cipher,
	NULL,
	sizeof(EVP_SMS4_XTS_CTX),
	NULL, NULL, sms4_xts_ctrl, NULL
};

const EVP_CIPHER *EVP_sms4_xts(void) {
	return &sms4_xts;
}
#endif /* OPENSSL_NO_SMS4 */