[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / hmac.c

/*
 * 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
 *
 * 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.
 *
 */

#include <crypto/algapi.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/slab.h>
#include <linux/string.h>

struct hmac_ctx {
	struct crypto_hash *child;
};

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_hash *tfm)
{
	return align_ptr(crypto_hash_ctx_aligned(tfm) +
			 crypto_hash_blocksize(tfm) * 2 +
			 crypto_hash_digestsize(tfm), sizeof(void *));
}

static int hmac_setkey(struct crypto_hash *parent,
		       const u8 *inkey, unsigned int keylen)
{
	int bs = crypto_hash_blocksize(parent);
	int ds = crypto_hash_digestsize(parent);
	char *ipad = crypto_hash_ctx_aligned(parent);
	char *opad = ipad + bs;
	char *digest = opad + bs;
	struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
	struct crypto_hash *tfm = ctx->child;
	unsigned int i;

	if (keylen > bs) {
		struct hash_desc desc;
		struct scatterlist tmp;
		int err;

		desc.tfm = tfm;
		desc.flags = crypto_hash_get_flags(parent);
		desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
		sg_init_one(&tmp, inkey, keylen);

		err = crypto_hash_digest(&desc, &tmp, keylen, digest);
		if (err)
			return err;

		inkey = digest;
		keylen = ds;
	}

	memcpy(ipad, inkey, keylen);
	memset(ipad + keylen, 0, bs - keylen);
	memcpy(opad, ipad, bs);

	for (i = 0; i < bs; i++) {
		ipad[i] ^= 0x36;
		opad[i] ^= 0x5c;
	}

	return 0;
}

static int hmac_init(struct hash_desc *pdesc)
{
	struct crypto_hash *parent = pdesc->tfm;
	int bs = crypto_hash_blocksize(parent);
	int ds = crypto_hash_digestsize(parent);
	char *ipad = crypto_hash_ctx_aligned(parent);
	struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, sizeof(void *));
	struct hash_desc desc;
	struct scatterlist tmp;
	int err;

	desc.tfm = ctx->child;
	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	sg_init_one(&tmp, ipad, bs);

	err = crypto_hash_init(&desc);
	if (unlikely(err))
		return err;

	return crypto_hash_update(&desc, &tmp, bs);
}

static int hmac_update(struct hash_desc *pdesc,
		       struct scatterlist *sg, unsigned int nbytes)
{
	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
	struct hash_desc desc;

	desc.tfm = ctx->child;
	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

	return crypto_hash_update(&desc, sg, nbytes);
}

static int hmac_final(struct hash_desc *pdesc, u8 *out)
{
	struct crypto_hash *parent = pdesc->tfm;
	int bs = crypto_hash_blocksize(parent);
	int ds = crypto_hash_digestsize(parent);
	char *opad = crypto_hash_ctx_aligned(parent) + bs;
	char *digest = opad + bs;
	struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
	struct hash_desc desc;
	struct scatterlist tmp;
	int err;

	desc.tfm = ctx->child;
	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	sg_init_one(&tmp, opad, bs + ds);

	err = crypto_hash_final(&desc, digest);
	if (unlikely(err))
		return err;

	return crypto_hash_digest(&desc, &tmp, bs + ds, out);
}

static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,
		       unsigned int nbytes, u8 *out)
{
	struct crypto_hash *parent = pdesc->tfm;
	int bs = crypto_hash_blocksize(parent);
	int ds = crypto_hash_digestsize(parent);
	char *ipad = crypto_hash_ctx_aligned(parent);
	char *opad = ipad + bs;
	char *digest = opad + bs;
	struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
	struct hash_desc desc;
	struct scatterlist sg1[2];
	struct scatterlist sg2[1];
	int err;

	desc.tfm = ctx->child;
	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;

	sg_init_table(sg1, 2);
	sg_set_buf(sg1, ipad, bs);
	scatterwalk_sg_chain(sg1, 2, sg);

	sg_init_table(sg2, 1);
	sg_set_buf(sg2, opad, bs + ds);

	err = crypto_hash_digest(&desc, sg1, nbytes + bs, digest);
	if (unlikely(err))
		return err;

	return crypto_hash_digest(&desc, sg2, bs + ds, out);
}

static int hmac_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_hash *hash;
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));

	hash = crypto_spawn_hash(spawn);
	if (IS_ERR(hash))
		return PTR_ERR(hash);

	ctx->child = hash;
	return 0;
}

static void hmac_exit_tfm(struct crypto_tfm *tfm)
{
	struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
	crypto_free_hash(ctx->child);
}

static void hmac_free(struct crypto_instance *inst)
{
	crypto_drop_spawn(crypto_instance_ctx(inst));
	kfree(inst);
}

static struct crypto_instance *hmac_alloc(struct rtattr **tb)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
	if (err)
		return ERR_PTR(err);

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_HASH,
				  CRYPTO_ALG_TYPE_HASH_MASK);
	if (IS_ERR(alg))
		return ERR_CAST(alg);

	inst = crypto_alloc_instance("hmac", alg);
	if (IS_ERR(inst))
		goto out_put_alg;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = &crypto_hash_type;

	inst->alg.cra_hash.digestsize =
		(alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
		CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
				       alg->cra_digest.dia_digestsize;

	inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) +
				ALIGN(inst->alg.cra_blocksize * 2 +
				      inst->alg.cra_hash.digestsize,
				      sizeof(void *));

	inst->alg.cra_init = hmac_init_tfm;
	inst->alg.cra_exit = hmac_exit_tfm;

	inst->alg.cra_hash.init = hmac_init;
	inst->alg.cra_hash.update = hmac_update;
	inst->alg.cra_hash.final = hmac_final;
	inst->alg.cra_hash.digest = hmac_digest;
	inst->alg.cra_hash.setkey = hmac_setkey;

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

static struct crypto_template hmac_tmpl = {
	.name = "hmac",
	.alloc = hmac_alloc,
	.free = hmac_free,
	.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);
}

module_init(hmac_module_init);
module_exit(hmac_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("HMAC hash algorithm");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Cryptographic API.
	3	*
	4	* HMAC: Keyed-Hashing for Message Authentication (RFC2104).
	5	*
	6	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
0796ae06	7	* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4 LT	8	*
	9	* The HMAC implementation is derived from USAGI.
	10	* Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
	11	*
	12	* This program is free software; you can redistribute it and/or modify it
	13	* under the terms of the GNU General Public License as published by the Free
0796ae06	14	* Software Foundation; either version 2 of the License, or (at your option)
1da177e4 LT	15	* any later version.
	16	*
	17	*/
0796ae06 HX	18
0796ae06 HX	19	#include <crypto/algapi.h>
b2ab4a57	20	#include <crypto/scatterwalk.h>
0796ae06 HX	21	#include <linux/err.h>
	22	#include <linux/init.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
378f058c	25	#include <linux/scatterlist.h>
0796ae06 HX	26	#include <linux/slab.h>
	27	#include <linux/string.h>
	28
	29	struct hmac_ctx {
	30	struct crypto_hash *child;
	31	};
1da177e4	32
0796ae06 HX	33	static inline void align_ptr(void p, unsigned int align)
	34	{
	35	return (void *)ALIGN((unsigned long)p, align);
	36	}
	37
	38	static inline struct hmac_ctx hmac_ctx(struct crypto_hash tfm)
	39	{
	40	return align_ptr(crypto_hash_ctx_aligned(tfm) +
	41	crypto_hash_blocksize(tfm) * 2 +
	42	crypto_hash_digestsize(tfm), sizeof(void *));
	43	}
	44
	45	static int hmac_setkey(struct crypto_hash *parent,
	46	const u8 *inkey, unsigned int keylen)
	47	{
	48	int bs = crypto_hash_blocksize(parent);
	49	int ds = crypto_hash_digestsize(parent);
	50	char *ipad = crypto_hash_ctx_aligned(parent);
	51	char *opad = ipad + bs;
	52	char *digest = opad + bs;
	53	struct hmac_ctx ctx = align_ptr(digest + ds, sizeof(void ));
	54	struct crypto_hash *tfm = ctx->child;
	55	unsigned int i;
	56
	57	if (keylen > bs) {
	58	struct hash_desc desc;
	59	struct scatterlist tmp;
	60	int err;
	61
	62	desc.tfm = tfm;
	63	desc.flags = crypto_hash_get_flags(parent);
	64	desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
a6767721	65	sg_init_one(&tmp, inkey, keylen);
0796ae06 HX	66
	67	err = crypto_hash_digest(&desc, &tmp, keylen, digest);
	68	if (err)
	69	return err;
	70
	71	inkey = digest;
	72	keylen = ds;
	73	}
	74
	75	memcpy(ipad, inkey, keylen);
	76	memset(ipad + keylen, 0, bs - keylen);
	77	memcpy(opad, ipad, bs);
	78
	79	for (i = 0; i < bs; i++) {
	80	ipad[i] ^= 0x36;
	81	opad[i] ^= 0x5c;
	82	}
	83
	84	return 0;
	85	}
	86
	87	static int hmac_init(struct hash_desc *pdesc)
	88	{
	89	struct crypto_hash *parent = pdesc->tfm;
	90	int bs = crypto_hash_blocksize(parent);
	91	int ds = crypto_hash_digestsize(parent);
	92	char *ipad = crypto_hash_ctx_aligned(parent);
	93	struct hmac_ctx ctx = align_ptr(ipad + bs 2 + ds, sizeof(void *));
	94	struct hash_desc desc;
	95	struct scatterlist tmp;
73af07de	96	int err;
0796ae06 HX	97
	98	desc.tfm = ctx->child;
	99	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
a6767721	100	sg_init_one(&tmp, ipad, bs);
0796ae06	101
73af07de HX	102	err = crypto_hash_init(&desc);
	103	if (unlikely(err))
	104	return err;
	105
	106	return crypto_hash_update(&desc, &tmp, bs);
0796ae06 HX	107	}
	108
	109	static int hmac_update(struct hash_desc *pdesc,
	110	struct scatterlist *sg, unsigned int nbytes)
	111	{
	112	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
	113	struct hash_desc desc;
	114
	115	desc.tfm = ctx->child;
	116	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	117
	118	return crypto_hash_update(&desc, sg, nbytes);
	119	}
	120
	121	static int hmac_final(struct hash_desc pdesc, u8 out)
	122	{
	123	struct crypto_hash *parent = pdesc->tfm;
	124	int bs = crypto_hash_blocksize(parent);
	125	int ds = crypto_hash_digestsize(parent);
	126	char *opad = crypto_hash_ctx_aligned(parent) + bs;
	127	char *digest = opad + bs;
	128	struct hmac_ctx ctx = align_ptr(digest + ds, sizeof(void ));
	129	struct hash_desc desc;
	130	struct scatterlist tmp;
73af07de	131	int err;
0796ae06 HX	132
	133	desc.tfm = ctx->child;
	134	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
a6767721	135	sg_init_one(&tmp, opad, bs + ds);
0796ae06	136
73af07de HX	137	err = crypto_hash_final(&desc, digest);
	138	if (unlikely(err))
	139	return err;
	140
	141	return crypto_hash_digest(&desc, &tmp, bs + ds, out);
0796ae06 HX	142	}
	143
	144	static int hmac_digest(struct hash_desc pdesc, struct scatterlist sg,
	145	unsigned int nbytes, u8 *out)
	146	{
	147	struct crypto_hash *parent = pdesc->tfm;
	148	int bs = crypto_hash_blocksize(parent);
	149	int ds = crypto_hash_digestsize(parent);
	150	char *ipad = crypto_hash_ctx_aligned(parent);
	151	char *opad = ipad + bs;
	152	char *digest = opad + bs;
	153	struct hmac_ctx ctx = align_ptr(digest + ds, sizeof(void ));
	154	struct hash_desc desc;
	155	struct scatterlist sg1[2];
	156	struct scatterlist sg2[1];
73af07de	157	int err;
0796ae06 HX	158
	159	desc.tfm = ctx->child;
	160	desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
	161
41fb2854	162	sg_init_table(sg1, 2);
0796ae06	163	sg_set_buf(sg1, ipad, bs);
b2ab4a57	164	scatterwalk_sg_chain(sg1, 2, sg);
78c2f0b8	165
41fb2854	166	sg_init_table(sg2, 1);
0796ae06 HX	167	sg_set_buf(sg2, opad, bs + ds);
0796ae06 HX	168
73af07de HX	169	err = crypto_hash_digest(&desc, sg1, nbytes + bs, digest);
	170	if (unlikely(err))
	171	return err;
	172
	173	return crypto_hash_digest(&desc, sg2, bs + ds, out);
0796ae06 HX	174	}
	175
	176	static int hmac_init_tfm(struct crypto_tfm *tfm)
	177	{
2e306ee0	178	struct crypto_hash *hash;
0796ae06 HX	179	struct crypto_instance inst = (void )tfm->__crt_alg;
	180	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	181	struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
	182
2e306ee0 HX	183	hash = crypto_spawn_hash(spawn);
	184	if (IS_ERR(hash))
	185	return PTR_ERR(hash);
0796ae06	186
2e306ee0	187	ctx->child = hash;
0796ae06 HX	188	return 0;
	189	}
	190
	191	static void hmac_exit_tfm(struct crypto_tfm *tfm)
	192	{
	193	struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
	194	crypto_free_hash(ctx->child);
	195	}
	196
	197	static void hmac_free(struct crypto_instance *inst)
	198	{
	199	crypto_drop_spawn(crypto_instance_ctx(inst));
	200	kfree(inst);
	201	}
	202
ebc610e5	203	static struct crypto_instance hmac_alloc(struct rtattr *tb)
0796ae06 HX	204	{
	205	struct crypto_instance *inst;
	206	struct crypto_alg *alg;
ebc610e5 HX	207	int err;
	208
	209	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
	210	if (err)
	211	return ERR_PTR(err);
0796ae06	212
ebc610e5 HX	213	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_HASH,
ebc610e5 HX	214	CRYPTO_ALG_TYPE_HASH_MASK);
0796ae06	215	if (IS_ERR(alg))
e231c2ee	216	return ERR_CAST(alg);
0796ae06 HX	217
	218	inst = crypto_alloc_instance("hmac", alg);
	219	if (IS_ERR(inst))
	220	goto out_put_alg;
	221
	222	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
	223	inst->alg.cra_priority = alg->cra_priority;
	224	inst->alg.cra_blocksize = alg->cra_blocksize;
	225	inst->alg.cra_alignmask = alg->cra_alignmask;
	226	inst->alg.cra_type = &crypto_hash_type;
	227
	228	inst->alg.cra_hash.digestsize =
	229	(alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	230	CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
	231	alg->cra_digest.dia_digestsize;
	232
	233	inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) +
	234	ALIGN(inst->alg.cra_blocksize * 2 +
	235	inst->alg.cra_hash.digestsize,
	236	sizeof(void *));
	237
	238	inst->alg.cra_init = hmac_init_tfm;
	239	inst->alg.cra_exit = hmac_exit_tfm;
	240
	241	inst->alg.cra_hash.init = hmac_init;
	242	inst->alg.cra_hash.update = hmac_update;
	243	inst->alg.cra_hash.final = hmac_final;
	244	inst->alg.cra_hash.digest = hmac_digest;
	245	inst->alg.cra_hash.setkey = hmac_setkey;
	246
	247	out_put_alg:
	248	crypto_mod_put(alg);
	249	return inst;
	250	}
	251
	252	static struct crypto_template hmac_tmpl = {
	253	.name = "hmac",
	254	.alloc = hmac_alloc,
	255	.free = hmac_free,
	256	.module = THIS_MODULE,
	257	};
	258
	259	static int __init hmac_module_init(void)
	260	{
	261	return crypto_register_template(&hmac_tmpl);
	262	}
	263
	264	static void __exit hmac_module_exit(void)
	265	{
	266	crypto_unregister_template(&hmac_tmpl);
	267	}
	268
	269	module_init(hmac_module_init);
	270	module_exit(hmac_module_exit);
	271
	272	MODULE_LICENSE("GPL");
	273	MODULE_DESCRIPTION("HMAC hash algorithm");