// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API.
 *
 * Single-block cipher operations.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/algapi.h>
#include <crypto/internal/cipher.h>
#include <linux/kernel.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"

static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
                            unsigned int keylen)
{
        struct cipher_alg *cia = crypto_cipher_alg(tfm);
        unsigned long alignmask = crypto_cipher_alignmask(tfm);
        int ret;
        u8 *buffer, *alignbuffer;
        unsigned long absize;

        absize = keylen + alignmask;
        buffer = kmalloc(absize, GFP_ATOMIC);
        if (!buffer)
                return -ENOMEM;

        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
        memcpy(alignbuffer, key, keylen);
        ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
        kfree_sensitive(buffer);
        return ret;

}

int crypto_cipher_setkey(struct crypto_cipher *tfm,
                         const u8 *key, unsigned int keylen)
{
        struct cipher_alg *cia = crypto_cipher_alg(tfm);
        unsigned long alignmask = crypto_cipher_alignmask(tfm);

        if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
                return -EINVAL;

        if ((unsigned long)key & alignmask)
                return setkey_unaligned(tfm, key, keylen);

        return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_setkey, "CRYPTO_INTERNAL");

static inline void cipher_crypt_one(struct crypto_cipher *tfm,
                                    u8 *dst, const u8 *src, bool enc)
{
        unsigned long alignmask = crypto_cipher_alignmask(tfm);
        struct cipher_alg *cia = crypto_cipher_alg(tfm);
        void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
                enc ? cia->cia_encrypt : cia->cia_decrypt;

        if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
                unsigned int bs = crypto_cipher_blocksize(tfm);
                u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
                u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);

                memcpy(tmp, src, bs);
                fn(crypto_cipher_tfm(tfm), tmp, tmp);
                memcpy(dst, tmp, bs);
        } else {
                fn(crypto_cipher_tfm(tfm), dst, src);
        }
}

void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
                               u8 *dst, const u8 *src)
{
        cipher_crypt_one(tfm, dst, src, true);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_encrypt_one, "CRYPTO_INTERNAL");

void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
                               u8 *dst, const u8 *src)
{
        cipher_crypt_one(tfm, dst, src, false);
}
EXPORT_SYMBOL_NS_GPL(crypto_cipher_decrypt_one, "CRYPTO_INTERNAL");

struct crypto_cipher *crypto_clone_cipher(struct crypto_cipher *cipher)
{
        struct crypto_tfm *tfm = crypto_cipher_tfm(cipher);
        struct crypto_alg *alg = tfm->__crt_alg;
        struct crypto_cipher *ncipher;
        struct crypto_tfm *ntfm;

        if (alg->cra_init)
                return ERR_PTR(-ENOSYS);

        if (unlikely(!crypto_mod_get(alg)))
                return ERR_PTR(-ESTALE);

        ntfm = __crypto_alloc_tfmgfp(alg, CRYPTO_ALG_TYPE_CIPHER,
                                     CRYPTO_ALG_TYPE_MASK, GFP_ATOMIC);
        if (IS_ERR(ntfm)) {
                crypto_mod_put(alg);
                return ERR_CAST(ntfm);
        }

        ntfm->crt_flags = tfm->crt_flags;

        ncipher = __crypto_cipher_cast(ntfm);

        return ncipher;
}
EXPORT_SYMBOL_GPL(crypto_clone_cipher);