crypto/ahash.c - linux - Git at Google

 /*
  * Asynchronous Cryptographic Hash operations.
  *
  * This is the asynchronous version of hash.c with notification of
  * completion via a callback.
  *
  * Copyright (c) 2008 Loc Ho <lho@amcc.com>
  *
  * 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/internal/hash.h>
 #include <crypto/scatterwalk.h>
 #include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>

 #include "internal.h"

 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
 {
 	return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
 			    halg);
 }

 static int hash_walk_next(struct crypto_hash_walk *walk)
 {
 	unsigned int alignmask = walk->alignmask;
 	unsigned int offset = walk->offset;
 	unsigned int nbytes = min(walk->entrylen,
 				  ((unsigned int)(PAGE_SIZE)) - offset);

 	walk->data = crypto_kmap(walk->pg, 0);
 	walk->data += offset;

 	if (offset & alignmask)
 		nbytes = alignmask + 1 - (offset & alignmask);

 	walk->entrylen -= nbytes;
 	return nbytes;
 }

 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
 {
 	struct scatterlist *sg;

 	sg = walk->sg;
 	walk->pg = sg_page(sg);
 	walk->offset = sg->offset;
 	walk->entrylen = sg->length;

 	if (walk->entrylen > walk->total)
 		walk->entrylen = walk->total;
 	walk->total -= walk->entrylen;

 	return hash_walk_next(walk);
 }

 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 {
 	unsigned int alignmask = walk->alignmask;
 	unsigned int nbytes = walk->entrylen;

 	walk->data -= walk->offset;

 	if (nbytes && walk->offset & alignmask && !err) {
 		walk->offset += alignmask - 1;
 		walk->offset = ALIGN(walk->offset, alignmask + 1);
 		walk->data += walk->offset;

 		nbytes = min(nbytes,
 			     ((unsigned int)(PAGE_SIZE)) - walk->offset);
 		walk->entrylen -= nbytes;

 		return nbytes;
 	}

 	crypto_kunmap(walk->data, 0);
 	crypto_yield(walk->flags);

 	if (err)
 		return err;

 	if (nbytes) {
 		walk->offset = 0;
 		walk->pg++;
 		return hash_walk_next(walk);
 	}

 	if (!walk->total)
 		return 0;

 	walk->sg = scatterwalk_sg_next(walk->sg);

 	return hash_walk_new_entry(walk);
 }
 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);

 int crypto_hash_walk_first(struct ahash_request *req,
 			   struct crypto_hash_walk *walk)
 {
 	walk->total = req->nbytes;

 	if (!walk->total)
 		return 0;

 	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
 	walk->sg = req->src;
 	walk->flags = req->base.flags;

 	return hash_walk_new_entry(walk);
 }
 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);

 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
 				  struct crypto_hash_walk *walk,
 				  struct scatterlist *sg, unsigned int len)
 {
 	walk->total = len;

 	if (!walk->total)
 		return 0;

 	walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
 	walk->sg = sg;
 	walk->flags = hdesc->flags;

 	return hash_walk_new_entry(walk);
 }

 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
 				unsigned int keylen)
 {
 	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
 	unsigned long alignmask = crypto_ahash_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 = ahash->setkey(tfm, alignbuffer, keylen);
 	memset(alignbuffer, 0, keylen);
 	kfree(buffer);
 	return ret;
 }

 static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
 			unsigned int keylen)
 {
 	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
 	unsigned long alignmask = crypto_ahash_alignmask(tfm);

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

 	return ahash->setkey(tfm, key, keylen);
 }

 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
 			  unsigned int keylen)
 {
 	return -ENOSYS;
 }

 static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 {
 	struct old_ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
 	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
 	struct ahash_alg *nalg = crypto_ahash_alg(crt);

 	if (alg->digestsize > PAGE_SIZE / 8)
 		return -EINVAL;

 	crt->init = alg->init;
 	crt->update = alg->update;
 	crt->final  = alg->final;
 	crt->digest = alg->digest;
 	crt->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
 	crt->digestsize = alg->digestsize;

 	nalg->setkey = alg->setkey;
 	nalg->halg.digestsize = alg->digestsize;

 	return 0;
 }

 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
 	struct ahash_alg *alg = crypto_ahash_alg(hash);
 	struct old_ahash_alg *oalg = crypto_old_ahash_alg(hash);

 	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 		return crypto_init_shash_ops_async(tfm);

 	if (oalg->init)
 		return crypto_init_ahash_ops(tfm, 0, 0);

 	hash->init = alg->init;
 	hash->update = alg->update;
 	hash->final  = alg->final;
 	hash->digest = alg->digest;
 	hash->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
 	hash->digestsize = alg->halg.digestsize;

 	return 0;
 }

 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
 {
 	if (alg->cra_type == &crypto_ahash_type)
 		return alg->cra_ctxsize;

 	return sizeof(struct crypto_shash *);
 }

 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 	__attribute__ ((unused));
 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
 {
 	seq_printf(m, "type         : ahash\n");
 	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 					     "yes" : "no");
 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 	seq_printf(m, "digestsize   : %u\n",
 		   __crypto_hash_alg_common(alg)->digestsize);
 }

 const struct crypto_type crypto_ahash_type = {
 	.extsize = crypto_ahash_extsize,
 	.init_tfm = crypto_ahash_init_tfm,
 #ifdef CONFIG_PROC_FS
 	.show = crypto_ahash_show,
 #endif
 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
 	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
 	.type = CRYPTO_ALG_TYPE_AHASH,
 	.tfmsize = offsetof(struct crypto_ahash, base),
 };
 EXPORT_SYMBOL_GPL(crypto_ahash_type);

 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 					u32 mask)
 {
 	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
 }
 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);

 static int ahash_prepare_alg(struct ahash_alg *alg)
 {
 	struct crypto_alg *base = &alg->halg.base;

 	if (alg->halg.digestsize > PAGE_SIZE / 8 ||
 	    alg->halg.statesize > PAGE_SIZE / 8)
 		return -EINVAL;

 	base->cra_type = &crypto_ahash_type;
 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;

 	return 0;
 }

 int crypto_register_ahash(struct ahash_alg *alg)
 {
 	struct crypto_alg *base = &alg->halg.base;
 	int err;

 	err = ahash_prepare_alg(alg);
 	if (err)
 		return err;

 	return crypto_register_alg(base);
 }
 EXPORT_SYMBOL_GPL(crypto_register_ahash);

 int crypto_unregister_ahash(struct ahash_alg *alg)
 {
 	return crypto_unregister_alg(&alg->halg.base);
 }
 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);

 int ahash_register_instance(struct crypto_template *tmpl,
 			    struct ahash_instance *inst)
 {
 	int err;

 	err = ahash_prepare_alg(&inst->alg);
 	if (err)
 		return err;

 	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
 }
 EXPORT_SYMBOL_GPL(ahash_register_instance);

 void ahash_free_instance(struct crypto_instance *inst)
 {
 	crypto_drop_spawn(crypto_instance_ctx(inst));
 	kfree(ahash_instance(inst));
 }
 EXPORT_SYMBOL_GPL(ahash_free_instance);

 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
 			    struct hash_alg_common *alg,
 			    struct crypto_instance *inst)
 {
 	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
 				  &crypto_ahash_type);
 }
 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);

 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
 {
 	struct crypto_alg *alg;

 	alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
 	return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
 }
 EXPORT_SYMBOL_GPL(ahash_attr_alg);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
	/*
	* Asynchronous Cryptographic Hash operations.
	*
	* This is the asynchronous version of hash.c with notification of
	* completion via a callback.
	*
	* Copyright (c) 2008 Loc Ho <lho@amcc.com>
	*
	* 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/internal/hash.h>
	#include <crypto/scatterwalk.h>
	#include <linux/err.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/seq_file.h>

	#include "internal.h"

	static inline struct ahash_alg crypto_ahash_alg(struct crypto_ahash hash)
	{
	return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
	halg);
	}

	static int hash_walk_next(struct crypto_hash_walk *walk)
	{
	unsigned int alignmask = walk->alignmask;
	unsigned int offset = walk->offset;
	unsigned int nbytes = min(walk->entrylen,
	((unsigned int)(PAGE_SIZE)) - offset);

	walk->data = crypto_kmap(walk->pg, 0);
	walk->data += offset;

	if (offset & alignmask)
	nbytes = alignmask + 1 - (offset & alignmask);

	walk->entrylen -= nbytes;
	return nbytes;
	}

	static int hash_walk_new_entry(struct crypto_hash_walk *walk)
	{
	struct scatterlist *sg;

	sg = walk->sg;
	walk->pg = sg_page(sg);
	walk->offset = sg->offset;
	walk->entrylen = sg->length;

	if (walk->entrylen > walk->total)
	walk->entrylen = walk->total;
	walk->total -= walk->entrylen;

	return hash_walk_next(walk);
	}

	int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
	{
	unsigned int alignmask = walk->alignmask;
	unsigned int nbytes = walk->entrylen;

	walk->data -= walk->offset;

	if (nbytes && walk->offset & alignmask && !err) {
	walk->offset += alignmask - 1;
	walk->offset = ALIGN(walk->offset, alignmask + 1);
	walk->data += walk->offset;

	nbytes = min(nbytes,
	((unsigned int)(PAGE_SIZE)) - walk->offset);
	walk->entrylen -= nbytes;

	return nbytes;
	}

	crypto_kunmap(walk->data, 0);
	crypto_yield(walk->flags);

	if (err)
	return err;

	if (nbytes) {
	walk->offset = 0;
	walk->pg++;
	return hash_walk_next(walk);
	}

	if (!walk->total)
	return 0;

	walk->sg = scatterwalk_sg_next(walk->sg);

	return hash_walk_new_entry(walk);
	}
	EXPORT_SYMBOL_GPL(crypto_hash_walk_done);

	int crypto_hash_walk_first(struct ahash_request *req,
	struct crypto_hash_walk *walk)
	{
	walk->total = req->nbytes;

	if (!walk->total)
	return 0;

	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
	walk->sg = req->src;
	walk->flags = req->base.flags;

	return hash_walk_new_entry(walk);
	}
	EXPORT_SYMBOL_GPL(crypto_hash_walk_first);

	int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
	struct crypto_hash_walk *walk,
	struct scatterlist *sg, unsigned int len)
	{
	walk->total = len;

	if (!walk->total)
	return 0;

	walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
	walk->sg = sg;
	walk->flags = hdesc->flags;

	return hash_walk_new_entry(walk);
	}

	static int ahash_setkey_unaligned(struct crypto_ahash tfm, const u8 key,
	unsigned int keylen)
	{
	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
	unsigned long alignmask = crypto_ahash_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 = ahash->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
	}

	static int ahash_setkey(struct crypto_ahash tfm, const u8 key,
	unsigned int keylen)
	{
	struct ahash_alg *ahash = crypto_ahash_alg(tfm);
	unsigned long alignmask = crypto_ahash_alignmask(tfm);

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

	return ahash->setkey(tfm, key, keylen);
	}

	static int ahash_nosetkey(struct crypto_ahash tfm, const u8 key,
	unsigned int keylen)
	{
	return -ENOSYS;
	}

	static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
	{
	struct old_ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
	struct ahash_alg *nalg = crypto_ahash_alg(crt);

	if (alg->digestsize > PAGE_SIZE / 8)
	return -EINVAL;

	crt->init = alg->init;
	crt->update = alg->update;
	crt->final = alg->final;
	crt->digest = alg->digest;
	crt->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
	crt->digestsize = alg->digestsize;

	nalg->setkey = alg->setkey;
	nalg->halg.digestsize = alg->digestsize;

	return 0;
	}

	static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
	{
	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
	struct ahash_alg *alg = crypto_ahash_alg(hash);
	struct old_ahash_alg *oalg = crypto_old_ahash_alg(hash);

	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
	return crypto_init_shash_ops_async(tfm);

	if (oalg->init)
	return crypto_init_ahash_ops(tfm, 0, 0);

	hash->init = alg->init;
	hash->update = alg->update;
	hash->final = alg->final;
	hash->digest = alg->digest;
	hash->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
	hash->digestsize = alg->halg.digestsize;

	return 0;
	}

	static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
	{
	if (alg->cra_type == &crypto_ahash_type)
	return alg->cra_ctxsize;

	return sizeof(struct crypto_shash *);
	}

	static void crypto_ahash_show(struct seq_file m, struct crypto_alg alg)
	__attribute__ ((unused));
	static void crypto_ahash_show(struct seq_file m, struct crypto_alg alg)
	{
	seq_printf(m, "type : ahash\n");
	seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
	"yes" : "no");
	seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
	seq_printf(m, "digestsize : %u\n",
	__crypto_hash_alg_common(alg)->digestsize);
	}

	const struct crypto_type crypto_ahash_type = {
	.extsize = crypto_ahash_extsize,
	.init_tfm = crypto_ahash_init_tfm,
	#ifdef CONFIG_PROC_FS
	.show = crypto_ahash_show,
	#endif
	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
	.type = CRYPTO_ALG_TYPE_AHASH,
	.tfmsize = offsetof(struct crypto_ahash, base),
	};
	EXPORT_SYMBOL_GPL(crypto_ahash_type);

	struct crypto_ahash crypto_alloc_ahash(const char alg_name, u32 type,
	u32 mask)
	{
	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
	}
	EXPORT_SYMBOL_GPL(crypto_alloc_ahash);

	static int ahash_prepare_alg(struct ahash_alg *alg)
	{
	struct crypto_alg *base = &alg->halg.base;

	if (alg->halg.digestsize > PAGE_SIZE / 8 \|\|
	alg->halg.statesize > PAGE_SIZE / 8)
	return -EINVAL;

	base->cra_type = &crypto_ahash_type;
	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
	base->cra_flags \|= CRYPTO_ALG_TYPE_AHASH;

	return 0;
	}

	int crypto_register_ahash(struct ahash_alg *alg)
	{
	struct crypto_alg *base = &alg->halg.base;
	int err;

	err = ahash_prepare_alg(alg);
	if (err)
	return err;

	return crypto_register_alg(base);
	}
	EXPORT_SYMBOL_GPL(crypto_register_ahash);

	int crypto_unregister_ahash(struct ahash_alg *alg)
	{
	return crypto_unregister_alg(&alg->halg.base);
	}
	EXPORT_SYMBOL_GPL(crypto_unregister_ahash);

	int ahash_register_instance(struct crypto_template *tmpl,
	struct ahash_instance *inst)
	{
	int err;

	err = ahash_prepare_alg(&inst->alg);
	if (err)
	return err;

	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
	}
	EXPORT_SYMBOL_GPL(ahash_register_instance);

	void ahash_free_instance(struct crypto_instance *inst)
	{
	crypto_drop_spawn(crypto_instance_ctx(inst));
	kfree(ahash_instance(inst));
	}
	EXPORT_SYMBOL_GPL(ahash_free_instance);

	int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
	struct hash_alg_common *alg,
	struct crypto_instance *inst)
	{
	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
	&crypto_ahash_type);
	}
	EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);

	struct hash_alg_common ahash_attr_alg(struct rtattr rta, u32 type, u32 mask)
	{
	struct crypto_alg *alg;

	alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
	return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
	}
	EXPORT_SYMBOL_GPL(ahash_attr_alg);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("Asynchronous cryptographic hash type");