crypto/api.c - kernel/msm - Gitiles

 /*
  * Scatterlist Cryptographic API.
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
  *
  * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
  * and Nettle, by Niels Möller.
  *
  * 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 <linux/compiler.h>
 #include <linux/init.h>
 #include <linux/crypto.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/kmod.h>
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include "internal.h"

 LIST_HEAD(crypto_alg_list);
 DECLARE_RWSEM(crypto_alg_sem);

 static inline int crypto_alg_get(struct crypto_alg *alg)
 {
 	return try_module_get(alg->cra_module);
 }

 static inline void crypto_alg_put(struct crypto_alg *alg)
 {
 	module_put(alg->cra_module);
 }

 static struct crypto_alg *crypto_alg_lookup(const char *name)
 {
 	struct crypto_alg *q, *alg = NULL;
 	int best = -1;

 	if (!name)
 		return NULL;

 	down_read(&crypto_alg_sem);

 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 		int exact, fuzzy;

 		exact = !strcmp(q->cra_driver_name, name);
 		fuzzy = !strcmp(q->cra_name, name);
 		if (!exact && !(fuzzy && q->cra_priority > best))
 			continue;

 		if (unlikely(!crypto_alg_get(q)))
 			continue;

 		best = q->cra_priority;
 		if (alg)
 			crypto_alg_put(alg);
 		alg = q;

 		if (exact)
 			break;
 	}

 	up_read(&crypto_alg_sem);
 	return alg;
 }

 /* A far more intelligent version of this is planned.  For now, just
  * try an exact match on the name of the algorithm. */
 static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name)
 {
 	return try_then_request_module(crypto_alg_lookup(name), name);
 }

 static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
 {
 	tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
 	flags &= ~CRYPTO_TFM_REQ_MASK;

 	switch (crypto_tfm_alg_type(tfm)) {
 	case CRYPTO_ALG_TYPE_CIPHER:
 		return crypto_init_cipher_flags(tfm, flags);

 	case CRYPTO_ALG_TYPE_DIGEST:
 		return crypto_init_digest_flags(tfm, flags);

 	case CRYPTO_ALG_TYPE_COMPRESS:
 		return crypto_init_compress_flags(tfm, flags);

 	default:
 		break;
 	}

 	BUG();
 	return -EINVAL;
 }

 static int crypto_init_ops(struct crypto_tfm *tfm)
 {
 	switch (crypto_tfm_alg_type(tfm)) {
 	case CRYPTO_ALG_TYPE_CIPHER:
 		return crypto_init_cipher_ops(tfm);

 	case CRYPTO_ALG_TYPE_DIGEST:
 		return crypto_init_digest_ops(tfm);

 	case CRYPTO_ALG_TYPE_COMPRESS:
 		return crypto_init_compress_ops(tfm);

 	default:
 		break;
 	}

 	BUG();
 	return -EINVAL;
 }

 static void crypto_exit_ops(struct crypto_tfm *tfm)
 {
 	switch (crypto_tfm_alg_type(tfm)) {
 	case CRYPTO_ALG_TYPE_CIPHER:
 		crypto_exit_cipher_ops(tfm);
 		break;

 	case CRYPTO_ALG_TYPE_DIGEST:
 		crypto_exit_digest_ops(tfm);
 		break;

 	case CRYPTO_ALG_TYPE_COMPRESS:
 		crypto_exit_compress_ops(tfm);
 		break;

 	default:
 		BUG();

 	}
 }

 static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
 {
 	unsigned int len;

 	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
 	default:
 		BUG();

 	case CRYPTO_ALG_TYPE_CIPHER:
 		len = crypto_cipher_ctxsize(alg, flags);
 		break;

 	case CRYPTO_ALG_TYPE_DIGEST:
 		len = crypto_digest_ctxsize(alg, flags);
 		break;

 	case CRYPTO_ALG_TYPE_COMPRESS:
 		len = crypto_compress_ctxsize(alg, flags);
 		break;
 	}

 	return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
 }

 struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags)
 {
 	struct crypto_tfm *tfm = NULL;
 	struct crypto_alg *alg;
 	unsigned int tfm_size;

 	alg = crypto_alg_mod_lookup(name);
 	if (alg == NULL)
 		goto out;

 	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
 	tfm = kzalloc(tfm_size, GFP_KERNEL);
 	if (tfm == NULL)
 		goto out_put;

 	tfm->__crt_alg = alg;

 	if (crypto_init_flags(tfm, flags))
 		goto out_free_tfm;

 	if (crypto_init_ops(tfm))
 		goto out_free_tfm;

 	if (alg->cra_init && alg->cra_init(tfm))
 		goto cra_init_failed;

 	goto out;

 cra_init_failed:
 	crypto_exit_ops(tfm);
 out_free_tfm:
 	kfree(tfm);
 	tfm = NULL;
 out_put:
 	crypto_alg_put(alg);
 out:
 	return tfm;
 }

 void crypto_free_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_alg *alg;
 	int size;

 	if (unlikely(!tfm))
 		return;

 	alg = tfm->__crt_alg;
 	size = sizeof(*tfm) + alg->cra_ctxsize;

 	if (alg->cra_exit)
 		alg->cra_exit(tfm);
 	crypto_exit_ops(tfm);
 	crypto_alg_put(alg);
 	memset(tfm, 0, size);
 	kfree(tfm);
 }

 static inline int crypto_set_driver_name(struct crypto_alg *alg)
 {
 	static const char suffix[] = "-generic";
 	char *driver_name = alg->cra_driver_name;
 	int len;

 	if (*driver_name)
 		return 0;

 	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
 		return -ENAMETOOLONG;

 	memcpy(driver_name + len, suffix, sizeof(suffix));
 	return 0;
 }

 int crypto_register_alg(struct crypto_alg *alg)
 {
 	int ret;
 	struct crypto_alg *q;

 	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
 		return -EINVAL;

 	if (alg->cra_alignmask & alg->cra_blocksize)
 		return -EINVAL;

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

 	if (alg->cra_priority < 0)
 		return -EINVAL;

 	ret = crypto_set_driver_name(alg);
 	if (unlikely(ret))
 		return ret;

 	down_write(&crypto_alg_sem);

 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 		if (q == alg) {
 			ret = -EEXIST;
 			goto out;
 		}
 	}

 	list_add(&alg->cra_list, &crypto_alg_list);
 out:
 	up_write(&crypto_alg_sem);
 	return ret;
 }

 int crypto_unregister_alg(struct crypto_alg *alg)
 {
 	int ret = -ENOENT;
 	struct crypto_alg *q;

 	BUG_ON(!alg->cra_module);

 	down_write(&crypto_alg_sem);
 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 		if (alg == q) {
 			list_del(&alg->cra_list);
 			ret = 0;
 			goto out;
 		}
 	}
 out:
 	up_write(&crypto_alg_sem);
 	return ret;
 }

 int crypto_alg_available(const char *name, u32 flags)
 {
 	int ret = 0;
 	struct crypto_alg *alg = crypto_alg_mod_lookup(name);

 	if (alg) {
 		crypto_alg_put(alg);
 		ret = 1;
 	}

 	return ret;
 }

 static int __init init_crypto(void)
 {
 	printk(KERN_INFO "Initializing Cryptographic API\n");
 	crypto_init_proc();
 	return 0;
 }

 __initcall(init_crypto);

 EXPORT_SYMBOL_GPL(crypto_register_alg);
 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
 EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
 EXPORT_SYMBOL_GPL(crypto_free_tfm);
 EXPORT_SYMBOL_GPL(crypto_alg_available);
	/*
	* Scatterlist Cryptographic API.
	*
	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
	* Copyright (c) 2002 David S. Miller (davem@redhat.com)
	* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
	*
	* Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
	* and Nettle, by Niels Möller.
	*
	* 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 <linux/compiler.h>
	#include <linux/init.h>
	#include <linux/crypto.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/kmod.h>
	#include <linux/rwsem.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include "internal.h"

	LIST_HEAD(crypto_alg_list);
	DECLARE_RWSEM(crypto_alg_sem);

	static inline int crypto_alg_get(struct crypto_alg *alg)
	{
	return try_module_get(alg->cra_module);
	}

	static inline void crypto_alg_put(struct crypto_alg *alg)
	{
	module_put(alg->cra_module);
	}

	static struct crypto_alg crypto_alg_lookup(const char name)
	{
	struct crypto_alg q, alg = NULL;
	int best = -1;

	if (!name)
	return NULL;

	down_read(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
	int exact, fuzzy;

	exact = !strcmp(q->cra_driver_name, name);
	fuzzy = !strcmp(q->cra_name, name);
	if (!exact && !(fuzzy && q->cra_priority > best))
	continue;

	if (unlikely(!crypto_alg_get(q)))
	continue;

	best = q->cra_priority;
	if (alg)
	crypto_alg_put(alg);
	alg = q;

	if (exact)
	break;
	}

	up_read(&crypto_alg_sem);
	return alg;
	}

	/* A far more intelligent version of this is planned. For now, just
	* try an exact match on the name of the algorithm. */
	static inline struct crypto_alg crypto_alg_mod_lookup(const char name)
	{
	return try_then_request_module(crypto_alg_lookup(name), name);
	}

	static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags)
	{
	tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK;
	flags &= ~CRYPTO_TFM_REQ_MASK;

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
	return crypto_init_cipher_flags(tfm, flags);

	case CRYPTO_ALG_TYPE_DIGEST:
	return crypto_init_digest_flags(tfm, flags);

	case CRYPTO_ALG_TYPE_COMPRESS:
	return crypto_init_compress_flags(tfm, flags);

	default:
	break;
	}

	BUG();
	return -EINVAL;
	}

	static int crypto_init_ops(struct crypto_tfm *tfm)
	{
	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
	return crypto_init_cipher_ops(tfm);

	case CRYPTO_ALG_TYPE_DIGEST:
	return crypto_init_digest_ops(tfm);

	case CRYPTO_ALG_TYPE_COMPRESS:
	return crypto_init_compress_ops(tfm);

	default:
	break;
	}

	BUG();
	return -EINVAL;
	}

	static void crypto_exit_ops(struct crypto_tfm *tfm)
	{
	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
	crypto_exit_cipher_ops(tfm);
	break;

	case CRYPTO_ALG_TYPE_DIGEST:
	crypto_exit_digest_ops(tfm);
	break;

	case CRYPTO_ALG_TYPE_COMPRESS:
	crypto_exit_compress_ops(tfm);
	break;

	default:
	BUG();

	}
	}

	static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags)
	{
	unsigned int len;

	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	default:
	BUG();

	case CRYPTO_ALG_TYPE_CIPHER:
	len = crypto_cipher_ctxsize(alg, flags);
	break;

	case CRYPTO_ALG_TYPE_DIGEST:
	len = crypto_digest_ctxsize(alg, flags);
	break;

	case CRYPTO_ALG_TYPE_COMPRESS:
	len = crypto_compress_ctxsize(alg, flags);
	break;
	}

	return len + (alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1));
	}

	struct crypto_tfm crypto_alloc_tfm(const char name, u32 flags)
	{
	struct crypto_tfm *tfm = NULL;
	struct crypto_alg *alg;
	unsigned int tfm_size;

	alg = crypto_alg_mod_lookup(name);
	if (alg == NULL)
	goto out;

	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags);
	tfm = kzalloc(tfm_size, GFP_KERNEL);
	if (tfm == NULL)
	goto out_put;

	tfm->__crt_alg = alg;

	if (crypto_init_flags(tfm, flags))
	goto out_free_tfm;

	if (crypto_init_ops(tfm))
	goto out_free_tfm;

	if (alg->cra_init && alg->cra_init(tfm))
	goto cra_init_failed;

	goto out;

	cra_init_failed:
	crypto_exit_ops(tfm);
	out_free_tfm:
	kfree(tfm);
	tfm = NULL;
	out_put:
	crypto_alg_put(alg);
	out:
	return tfm;
	}

	void crypto_free_tfm(struct crypto_tfm *tfm)
	{
	struct crypto_alg *alg;
	int size;

	if (unlikely(!tfm))
	return;

	alg = tfm->__crt_alg;
	size = sizeof(*tfm) + alg->cra_ctxsize;

	if (alg->cra_exit)
	alg->cra_exit(tfm);
	crypto_exit_ops(tfm);
	crypto_alg_put(alg);
	memset(tfm, 0, size);
	kfree(tfm);
	}

	static inline int crypto_set_driver_name(struct crypto_alg *alg)
	{
	static const char suffix[] = "-generic";
	char *driver_name = alg->cra_driver_name;
	int len;

	if (*driver_name)
	return 0;

	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
	return -ENAMETOOLONG;

	memcpy(driver_name + len, suffix, sizeof(suffix));
	return 0;
	}

	int crypto_register_alg(struct crypto_alg *alg)
	{
	int ret;
	struct crypto_alg *q;

	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
	return -EINVAL;

	if (alg->cra_alignmask & alg->cra_blocksize)
	return -EINVAL;

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

	if (alg->cra_priority < 0)
	return -EINVAL;

	ret = crypto_set_driver_name(alg);
	if (unlikely(ret))
	return ret;

	down_write(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
	if (q == alg) {
	ret = -EEXIST;
	goto out;
	}
	}

	list_add(&alg->cra_list, &crypto_alg_list);
	out:
	up_write(&crypto_alg_sem);
	return ret;
	}

	int crypto_unregister_alg(struct crypto_alg *alg)
	{
	int ret = -ENOENT;
	struct crypto_alg *q;

	BUG_ON(!alg->cra_module);

	down_write(&crypto_alg_sem);
	list_for_each_entry(q, &crypto_alg_list, cra_list) {
	if (alg == q) {
	list_del(&alg->cra_list);
	ret = 0;
	goto out;
	}
	}
	out:
	up_write(&crypto_alg_sem);
	return ret;
	}

	int crypto_alg_available(const char *name, u32 flags)
	{
	int ret = 0;
	struct crypto_alg *alg = crypto_alg_mod_lookup(name);

	if (alg) {
	crypto_alg_put(alg);
	ret = 1;
	}

	return ret;
	}

	static int __init init_crypto(void)
	{
	printk(KERN_INFO "Initializing Cryptographic API\n");
	crypto_init_proc();
	return 0;
	}

	__initcall(init_crypto);

	EXPORT_SYMBOL_GPL(crypto_register_alg);
	EXPORT_SYMBOL_GPL(crypto_unregister_alg);
	EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
	EXPORT_SYMBOL_GPL(crypto_free_tfm);
	EXPORT_SYMBOL_GPL(crypto_alg_available);