#include <crypto/internal/cipher.h>
#include <crypto/internal/hash.h>
#include <crypto/utils.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
0x02020202, 0x02020202, 0x02020202, 0x02020202,
0x03030303, 0x03030303, 0x03030303, 0x03030303};
struct xcbc_tfm_ctx {
struct crypto_cipher *child;
u8 consts[];
};
#define XCBC_BLOCKSIZE 16
static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
const u8 *inkey, unsigned int keylen)
{
struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);
u8 *consts = ctx->consts;
int err = 0;
u8 key1[XCBC_BLOCKSIZE];
int bs = sizeof(key1);
if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen)))
return err;
crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs);
crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2);
crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks);
return crypto_cipher_setkey(ctx->child, key1, bs);
}
static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
{
int bs = crypto_shash_blocksize(pdesc->tfm);
u8 *prev = shash_desc_ctx(pdesc);
memset(prev, 0, bs);
return 0;
}
static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p,
unsigned int len)
{
struct crypto_shash *parent = pdesc->tfm;
struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_blocksize(parent);
u8 *prev = shash_desc_ctx(pdesc);
do {
crypto_xor(prev, p, bs);
crypto_cipher_encrypt_one(tfm, prev, prev);
p += bs;
len -= bs;
} while (len >= bs);
return len;
}
static int crypto_xcbc_digest_finup(struct shash_desc *pdesc, const u8 *src,
unsigned int len, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);
struct crypto_cipher *tfm = tctx->child;
int bs = crypto_shash_blocksize(parent);
u8 *prev = shash_desc_ctx(pdesc);
unsigned int offset = 0;
crypto_xor(prev, src, len);
if (len != bs) {
prev[len] ^= 0x80;
offset += bs;
}
crypto_xor(prev, &tctx->consts[offset], bs);
crypto_cipher_encrypt_one(tfm, out, prev);
return 0;
}
static int xcbc_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_cipher *cipher;
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
ctx->child = cipher;
return 0;
};
static void xcbc_exit_tfm(struct crypto_tfm *tfm)
{
struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->child);
}
static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct shash_instance *inst;
struct crypto_cipher_spawn *spawn;
struct crypto_alg *alg;
u32 mask;
int err;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
if (err)
return err;
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst)
return -ENOMEM;
spawn = shash_instance_ctx(inst);
err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
goto err_free_inst;
alg = crypto_spawn_cipher_alg(spawn);
err = -EINVAL;
if (alg->cra_blocksize != XCBC_BLOCKSIZE)
goto err_free_inst;
err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
if (err)
goto err_free_inst;
inst->alg.base.cra_priority = alg->cra_priority;
inst->alg.base.cra_blocksize = alg->cra_blocksize;
inst->alg.base.cra_ctxsize = sizeof(struct xcbc_tfm_ctx) +
alg->cra_blocksize * 2;
inst->alg.base.cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY |
CRYPTO_AHASH_ALG_FINAL_NONZERO;
inst->alg.digestsize = alg->cra_blocksize;
inst->alg.descsize = alg->cra_blocksize;
inst->alg.base.cra_init = xcbc_init_tfm;
inst->alg.base.cra_exit = xcbc_exit_tfm;
inst->alg.init = crypto_xcbc_digest_init;
inst->alg.update = crypto_xcbc_digest_update;
inst->alg.finup = crypto_xcbc_digest_finup;
inst->alg.setkey = crypto_xcbc_digest_setkey;
inst->free = shash_free_singlespawn_instance;
err = shash_register_instance(tmpl, inst);
if (err) {
err_free_inst:
shash_free_singlespawn_instance(inst);
}
return err;
}
static struct crypto_template crypto_xcbc_tmpl = {
.name = "xcbc",
.create = xcbc_create,
.module = THIS_MODULE,
};
static int __init crypto_xcbc_module_init(void)
{
return crypto_register_template(&crypto_xcbc_tmpl);
}
static void __exit crypto_xcbc_module_exit(void)
{
crypto_unregister_template(&crypto_xcbc_tmpl);
}
module_init(crypto_xcbc_module_init);
module_exit(crypto_xcbc_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("XCBC keyed hash algorithm");
MODULE_ALIAS_CRYPTO("xcbc");
MODULE_IMPORT_NS("CRYPTO_INTERNAL");
