/*      $OpenBSD: e_sm4.c,v 1.13 2024/04/09 13:52:41 beck Exp $ */
/*
 * Copyright (c) 2017, 2019 Ribose Inc
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <openssl/opensslconf.h>

#ifndef OPENSSL_NO_SM4
#include <openssl/evp.h>
#include <openssl/modes.h>
#include <openssl/sm4.h>

#include "evp_local.h"

typedef struct {
        SM4_KEY ks;
} EVP_SM4_KEY;

static int
sm4_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
        SM4_set_key(key, ctx->cipher_data);
        return 1;
}

static void
sm4_cbc_encrypt(const unsigned char *in, unsigned char *out, size_t len,
    const SM4_KEY *key, unsigned char *ivec, const int enc)
{
        if (enc)
                CRYPTO_cbc128_encrypt(in, out, len, key, ivec,
                    (block128_f)SM4_encrypt);
        else
                CRYPTO_cbc128_decrypt(in, out, len, key, ivec,
                    (block128_f)SM4_decrypt);
}

static void
sm4_cfb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
    const SM4_KEY *key, unsigned char *ivec, int *num, const int enc)
{
        CRYPTO_cfb128_encrypt(in, out, length, key, ivec, num, enc,
            (block128_f)SM4_encrypt);
}

static void
sm4_ecb_encrypt(const unsigned char *in, unsigned char *out, const SM4_KEY *key,
    const int enc)
{
        if (enc)
                SM4_encrypt(in, out, key);
        else
                SM4_decrypt(in, out, key);
}

static void
sm4_ofb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
    const SM4_KEY *key, unsigned char *ivec, int *num)
{
        CRYPTO_ofb128_encrypt(in, out, length, key, ivec, num,
            (block128_f)SM4_encrypt);
}

static int
sm4_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl)
{
        while (inl >= EVP_MAXCHUNK) {
                sm4_cbc_encrypt(in, out, EVP_MAXCHUNK, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->iv, ctx->encrypt);
                inl -= EVP_MAXCHUNK;
                in += EVP_MAXCHUNK;
                out += EVP_MAXCHUNK;
        }

        if (inl)
                sm4_cbc_encrypt(in, out, inl, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->iv, ctx->encrypt);

        return 1;
}

static int
sm4_cfb128_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl)
{
        size_t chunk = EVP_MAXCHUNK;

        if (inl < chunk)
                chunk = inl;

        while (inl && inl >= chunk) {
                sm4_cfb128_encrypt(in, out, chunk, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->iv, &ctx->num, ctx->encrypt);
                inl -= chunk;
                in += chunk;
                out += chunk;
                if (inl < chunk)
                        chunk = inl;
        }

        return 1;
}

static int
sm4_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl)
{
        size_t i, bl;

        bl = ctx->cipher->block_size;

        if (inl < bl)
                return 1;

        inl -= bl;

        for (i = 0; i <= inl; i += bl)
                sm4_ecb_encrypt(in + i, out + i, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->encrypt);

        return 1;
}

static int
sm4_ofb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in, size_t inl)
{
        while (inl >= EVP_MAXCHUNK) {
                sm4_ofb128_encrypt(in, out, EVP_MAXCHUNK, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->iv, &ctx->num);
                inl -= EVP_MAXCHUNK;
                in += EVP_MAXCHUNK;
                out += EVP_MAXCHUNK;
        }

        if (inl)
                sm4_ofb128_encrypt(in, out, inl, &((EVP_SM4_KEY *)ctx->cipher_data)->ks, ctx->iv, &ctx->num);

        return 1;
}

static const EVP_CIPHER sm4_cbc = {
        .nid = NID_sm4_cbc,
        .block_size = 16,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CBC_MODE,
        .init = sm4_init_key,
        .do_cipher = sm4_cbc_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_SM4_KEY),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = NULL,
};

const EVP_CIPHER *
EVP_sm4_cbc(void)
{
        return &sm4_cbc;
}
LCRYPTO_ALIAS(EVP_sm4_cbc);

static const EVP_CIPHER sm4_cfb128 = {
        .nid = NID_sm4_cfb128,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CFB_MODE,
        .init = sm4_init_key,
        .do_cipher = sm4_cfb128_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_SM4_KEY),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = NULL,
};

const EVP_CIPHER *
EVP_sm4_cfb128(void)
{
        return &sm4_cfb128;
}
LCRYPTO_ALIAS(EVP_sm4_cfb128);

static const EVP_CIPHER sm4_ofb = {
        .nid = NID_sm4_ofb128,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_OFB_MODE,
        .init = sm4_init_key,
        .do_cipher = sm4_ofb_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_SM4_KEY),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = NULL,
};

const EVP_CIPHER *
EVP_sm4_ofb(void)
{
        return &sm4_ofb;
}
LCRYPTO_ALIAS(EVP_sm4_ofb);

static const EVP_CIPHER sm4_ecb = {
        .nid = NID_sm4_ecb,
        .block_size = 16,
        .key_len = 16,
        .iv_len = 0,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
        .init = sm4_init_key,
        .do_cipher = sm4_ecb_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_SM4_KEY),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = NULL,
};

const EVP_CIPHER *
EVP_sm4_ecb(void)
{
        return &sm4_ecb;
}
LCRYPTO_ALIAS(EVP_sm4_ecb);

static int
sm4_ctr_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out, const unsigned char *in,
    size_t len)
{
        EVP_SM4_KEY *key = ((EVP_SM4_KEY *)(ctx)->cipher_data);

        CRYPTO_ctr128_encrypt(in, out, len, &key->ks, ctx->iv, ctx->buf,
            &ctx->num, (block128_f)SM4_encrypt);
        return 1;
}

static const EVP_CIPHER sm4_ctr_mode = {
        .nid = NID_sm4_ctr,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_CTR_MODE,
        .init = sm4_init_key,
        .do_cipher = sm4_ctr_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_SM4_KEY),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = NULL,
};

const EVP_CIPHER *
EVP_sm4_ctr(void)
{
        return &sm4_ctr_mode;
}
LCRYPTO_ALIAS(EVP_sm4_ctr);
#endif