bcachefs-tools/include/crypto/algapi.h

/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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.
 *
 */
#ifndef _CRYPTO_ALGAPI_H
#define _CRYPTO_ALGAPI_H

#include <linux/crypto.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/kthread.h>

struct crypto_aead;
struct crypto_instance;
struct module;
struct rtattr;
struct seq_file;
struct sk_buff;

struct crypto_type {
	unsigned int (*ctxsize)(struct crypto_alg *alg, u32 type, u32 mask);
	unsigned int (*extsize)(struct crypto_alg *alg);
	int (*init)(struct crypto_tfm *tfm, u32 type, u32 mask);
	int (*init_tfm)(struct crypto_tfm *tfm);
	void (*show)(struct seq_file *m, struct crypto_alg *alg);
	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask);
	void (*free)(struct crypto_instance *inst);

	unsigned int type;
	unsigned int maskclear;
	unsigned int maskset;
	unsigned int tfmsize;
};

struct crypto_instance {
	struct crypto_alg alg;

	struct crypto_template *tmpl;
	struct hlist_node list;

	void *__ctx[] CRYPTO_MINALIGN_ATTR;
};

struct crypto_template {
	struct list_head list;
	struct hlist_head instances;
	struct module *module;

	struct crypto_instance *(*alloc)(struct rtattr **tb);
	void (*free)(struct crypto_instance *inst);
	int (*create)(struct crypto_template *tmpl, struct rtattr **tb);

	char name[CRYPTO_MAX_ALG_NAME];
};

struct scatter_walk {
	struct scatterlist *sg;
	unsigned int offset;
};

struct blkcipher_walk {
	union {
		struct {
			struct page *page;
			unsigned long offset;
		} phys;

		struct {
			u8 *page;
			u8 *addr;
		} virt;
	} src, dst;

	struct scatter_walk in;
	unsigned int nbytes;

	struct scatter_walk out;
	unsigned int total;

	void *page;
	u8 *buffer;
	u8 *iv;
	unsigned int ivsize;

	int flags;
	unsigned int walk_blocksize;
	unsigned int cipher_blocksize;
	unsigned int alignmask;
};

extern const struct crypto_type crypto_blkcipher_type;

struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb);
int crypto_check_attr_type(struct rtattr **tb, u32 type);
const char *crypto_attr_alg_name(struct rtattr *rta);
struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
				    const struct crypto_type *frontend,
				    u32 type, u32 mask);

static inline struct crypto_alg *crypto_attr_alg(struct rtattr *rta,
						 u32 type, u32 mask)
{
	return crypto_attr_alg2(rta, NULL, type, mask);
}

int crypto_attr_u32(struct rtattr *rta, u32 *num);

/* These functions require the input/output to be aligned as u32. */
void crypto_inc(u8 *a, unsigned int size);
void crypto_xor(u8 *dst, const u8 *src, unsigned int size);

int blkcipher_walk_done(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk, int err);
int blkcipher_walk_virt(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk);
int blkcipher_walk_phys(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk);
int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
			      struct blkcipher_walk *walk,
			      unsigned int blocksize);
int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
				   struct blkcipher_walk *walk,
				   struct crypto_aead *tfm,
				   unsigned int blocksize);

static inline void *crypto_tfm_ctx_aligned(struct crypto_tfm *tfm)
{
	return PTR_ALIGN(crypto_tfm_ctx(tfm),
			 crypto_tfm_alg_alignmask(tfm) + 1);
}

static inline struct crypto_instance *crypto_tfm_alg_instance(
	struct crypto_tfm *tfm)
{
	return container_of(tfm->__crt_alg, struct crypto_instance, alg);
}

static inline void *crypto_instance_ctx(struct crypto_instance *inst)
{
	return inst->__ctx;
}

static inline void *crypto_blkcipher_ctx(struct crypto_blkcipher *tfm)
{
	return crypto_tfm_ctx(&tfm->base);
}

static inline void *crypto_blkcipher_ctx_aligned(struct crypto_blkcipher *tfm)
{
	return crypto_tfm_ctx_aligned(&tfm->base);
}

static inline struct cipher_alg *crypto_cipher_alg(struct crypto_cipher *tfm)
{
	return &crypto_cipher_tfm(tfm)->__crt_alg->cra_cipher;
}

static inline void blkcipher_walk_init(struct blkcipher_walk *walk,
				       struct scatterlist *dst,
				       struct scatterlist *src,
				       unsigned int nbytes)
{
	walk->in.sg = src;
	walk->out.sg = dst;
	walk->total = nbytes;
}

static inline struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb,
						     u32 type, u32 mask)
{
	return crypto_attr_alg(tb[1], type, mask);
}

static inline int crypto_requires_sync(u32 type, u32 mask)
{
	return (type ^ CRYPTO_ALG_ASYNC) & mask & CRYPTO_ALG_ASYNC;
}

noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size);

/**
 * crypto_memneq - Compare two areas of memory without leaking
 *		   timing information.
 *
 * @a: One area of memory
 * @b: Another area of memory
 * @size: The size of the area.
 *
 * Returns 0 when data is equal, 1 otherwise.
 */
static inline int crypto_memneq(const void *a, const void *b, size_t size)
{
	return __crypto_memneq(a, b, size) != 0UL ? 1 : 0;
}

static inline void crypto_yield(u32 flags)
{
#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_VOLUNTARY)
	if (flags & CRYPTO_TFM_REQ_MAY_SLEEP)
		cond_resched();
#endif
}

#endif	/* _CRYPTO_ALGAPI_H */