linux/crypto/hmac.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

263 lines
6.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Cryptographic API.
*
* HMAC: Keyed-Hashing for Message Authentication (RFC2104).
*
* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
*
* The HMAC implementation is derived from USAGI.
* Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
*/
#include <crypto/hmac.h>
#include <crypto/internal/hash.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/string.h>
struct hmac_ctx {
struct crypto_shash *hash;
};
static inline void *align_ptr(void *p, unsigned int align)
{
return (void *)ALIGN((unsigned long)p, align);
}
static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
{
return align_ptr(crypto_shash_ctx_aligned(tfm) +
crypto_shash_statesize(tfm) * 2,
crypto_tfm_ctx_alignment());
}
static int hmac_setkey(struct crypto_shash *parent,
const u8 *inkey, unsigned int keylen)
{
int bs = crypto_shash_blocksize(parent);
int ds = crypto_shash_digestsize(parent);
int ss = crypto_shash_statesize(parent);
char *ipad = crypto_shash_ctx_aligned(parent);
char *opad = ipad + ss;
struct hmac_ctx *ctx = align_ptr(opad + ss,
crypto_tfm_ctx_alignment());
struct crypto_shash *hash = ctx->hash;
SHASH_DESC_ON_STACK(shash, hash);
unsigned int i;
shash->tfm = hash;
if (keylen > bs) {
int err;
err = crypto_shash_digest(shash, inkey, keylen, ipad);
if (err)
return err;
keylen = ds;
} else
memcpy(ipad, inkey, keylen);
memset(ipad + keylen, 0, bs - keylen);
memcpy(opad, ipad, bs);
for (i = 0; i < bs; i++) {
ipad[i] ^= HMAC_IPAD_VALUE;
opad[i] ^= HMAC_OPAD_VALUE;
}
return crypto_shash_init(shash) ?:
crypto_shash_update(shash, ipad, bs) ?:
crypto_shash_export(shash, ipad) ?:
crypto_shash_init(shash) ?:
crypto_shash_update(shash, opad, bs) ?:
crypto_shash_export(shash, opad);
}
static int hmac_export(struct shash_desc *pdesc, void *out)
{
struct shash_desc *desc = shash_desc_ctx(pdesc);
return crypto_shash_export(desc, out);
}
static int hmac_import(struct shash_desc *pdesc, const void *in)
{
struct shash_desc *desc = shash_desc_ctx(pdesc);
struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
desc->tfm = ctx->hash;
return crypto_shash_import(desc, in);
}
static int hmac_init(struct shash_desc *pdesc)
{
return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
}
static int hmac_update(struct shash_desc *pdesc,
const u8 *data, unsigned int nbytes)
{
struct shash_desc *desc = shash_desc_ctx(pdesc);
return crypto_shash_update(desc, data, nbytes);
}
static int hmac_final(struct shash_desc *pdesc, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
int ds = crypto_shash_digestsize(parent);
int ss = crypto_shash_statesize(parent);
char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
return crypto_shash_final(desc, out) ?:
crypto_shash_import(desc, opad) ?:
crypto_shash_finup(desc, out, ds, out);
}
static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
unsigned int nbytes, u8 *out)
{
struct crypto_shash *parent = pdesc->tfm;
int ds = crypto_shash_digestsize(parent);
int ss = crypto_shash_statesize(parent);
char *opad = crypto_shash_ctx_aligned(parent) + ss;
struct shash_desc *desc = shash_desc_ctx(pdesc);
return crypto_shash_finup(desc, data, nbytes, out) ?:
crypto_shash_import(desc, opad) ?:
crypto_shash_finup(desc, out, ds, out);
}
static int hmac_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_shash *parent = __crypto_shash_cast(tfm);
struct crypto_shash *hash;
struct crypto_instance *inst = (void *)tfm->__crt_alg;
struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
struct hmac_ctx *ctx = hmac_ctx(parent);
hash = crypto_spawn_shash(spawn);
if (IS_ERR(hash))
return PTR_ERR(hash);
parent->descsize = sizeof(struct shash_desc) +
crypto_shash_descsize(hash);
if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE))
return -EINVAL;
ctx->hash = hash;
return 0;
}
static void hmac_exit_tfm(struct crypto_tfm *tfm)
{
struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
crypto_free_shash(ctx->hash);
}
static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct shash_instance *inst;
struct crypto_alg *alg;
struct shash_alg *salg;
int err;
int ds;
int ss;
err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
if (err)
return err;
salg = shash_attr_alg(tb[1], 0, 0);
if (IS_ERR(salg))
return PTR_ERR(salg);
alg = &salg->base;
/* The underlying hash algorithm must be unkeyed */
err = -EINVAL;
if (crypto_shash_alg_has_setkey(salg))
goto out_put_alg;
ds = salg->digestsize;
ss = salg->statesize;
if (ds > alg->cra_blocksize ||
ss < alg->cra_blocksize)
goto out_put_alg;
inst = shash_alloc_instance("hmac", alg);
err = PTR_ERR(inst);
if (IS_ERR(inst))
goto out_put_alg;
err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
shash_crypto_instance(inst));
if (err)
goto out_free_inst;
inst->alg.base.cra_priority = alg->cra_priority;
inst->alg.base.cra_blocksize = alg->cra_blocksize;
inst->alg.base.cra_alignmask = alg->cra_alignmask;
ss = ALIGN(ss, alg->cra_alignmask + 1);
inst->alg.digestsize = ds;
inst->alg.statesize = ss;
inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
ALIGN(ss * 2, crypto_tfm_ctx_alignment());
inst->alg.base.cra_init = hmac_init_tfm;
inst->alg.base.cra_exit = hmac_exit_tfm;
inst->alg.init = hmac_init;
inst->alg.update = hmac_update;
inst->alg.final = hmac_final;
inst->alg.finup = hmac_finup;
inst->alg.export = hmac_export;
inst->alg.import = hmac_import;
inst->alg.setkey = hmac_setkey;
err = shash_register_instance(tmpl, inst);
if (err) {
out_free_inst:
shash_free_instance(shash_crypto_instance(inst));
}
out_put_alg:
crypto_mod_put(alg);
return err;
}
static struct crypto_template hmac_tmpl = {
.name = "hmac",
.create = hmac_create,
.free = shash_free_instance,
.module = THIS_MODULE,
};
static int __init hmac_module_init(void)
{
return crypto_register_template(&hmac_tmpl);
}
static void __exit hmac_module_exit(void)
{
crypto_unregister_template(&hmac_tmpl);
}
subsys_initcall(hmac_module_init);
module_exit(hmac_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("HMAC hash algorithm");
MODULE_ALIAS_CRYPTO("hmac");