linux/include/crypto/akcipher.h
Waiman Long 453431a549 mm, treewide: rename kzfree() to kfree_sensitive()
As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07 11:33:22 -07:00

417 lines
13 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Public Key Encryption
*
* Copyright (c) 2015, Intel Corporation
* Authors: Tadeusz Struk <tadeusz.struk@intel.com>
*/
#ifndef _CRYPTO_AKCIPHER_H
#define _CRYPTO_AKCIPHER_H
#include <linux/crypto.h>
/**
* struct akcipher_request - public key request
*
* @base: Common attributes for async crypto requests
* @src: Source data
* For verify op this is signature + digest, in that case
* total size of @src is @src_len + @dst_len.
* @dst: Destination data (Should be NULL for verify op)
* @src_len: Size of the input buffer
* For verify op it's size of signature part of @src, this part
* is supposed to be operated by cipher.
* @dst_len: Size of @dst buffer (for all ops except verify).
* It needs to be at least as big as the expected result
* depending on the operation.
* After operation it will be updated with the actual size of the
* result.
* In case of error where the dst sgl size was insufficient,
* it will be updated to the size required for the operation.
* For verify op this is size of digest part in @src.
* @__ctx: Start of private context data
*/
struct akcipher_request {
struct crypto_async_request base;
struct scatterlist *src;
struct scatterlist *dst;
unsigned int src_len;
unsigned int dst_len;
void *__ctx[] CRYPTO_MINALIGN_ATTR;
};
/**
* struct crypto_akcipher - user-instantiated objects which encapsulate
* algorithms and core processing logic
*
* @base: Common crypto API algorithm data structure
*/
struct crypto_akcipher {
struct crypto_tfm base;
};
/**
* struct akcipher_alg - generic public key algorithm
*
* @sign: Function performs a sign operation as defined by public key
* algorithm. In case of error, where the dst_len was insufficient,
* the req->dst_len will be updated to the size required for the
* operation
* @verify: Function performs a complete verify operation as defined by
* public key algorithm, returning verification status. Requires
* digest value as input parameter.
* @encrypt: Function performs an encrypt operation as defined by public key
* algorithm. In case of error, where the dst_len was insufficient,
* the req->dst_len will be updated to the size required for the
* operation
* @decrypt: Function performs a decrypt operation as defined by public key
* algorithm. In case of error, where the dst_len was insufficient,
* the req->dst_len will be updated to the size required for the
* operation
* @set_pub_key: Function invokes the algorithm specific set public key
* function, which knows how to decode and interpret
* the BER encoded public key and parameters
* @set_priv_key: Function invokes the algorithm specific set private key
* function, which knows how to decode and interpret
* the BER encoded private key and parameters
* @max_size: Function returns dest buffer size required for a given key.
* @init: Initialize the cryptographic transformation object.
* This function is used to initialize the cryptographic
* transformation object. This function is called only once at
* the instantiation time, right after the transformation context
* was allocated. In case the cryptographic hardware has some
* special requirements which need to be handled by software, this
* function shall check for the precise requirement of the
* transformation and put any software fallbacks in place.
* @exit: Deinitialize the cryptographic transformation object. This is a
* counterpart to @init, used to remove various changes set in
* @init.
*
* @reqsize: Request context size required by algorithm implementation
* @base: Common crypto API algorithm data structure
*/
struct akcipher_alg {
int (*sign)(struct akcipher_request *req);
int (*verify)(struct akcipher_request *req);
int (*encrypt)(struct akcipher_request *req);
int (*decrypt)(struct akcipher_request *req);
int (*set_pub_key)(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen);
int (*set_priv_key)(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen);
unsigned int (*max_size)(struct crypto_akcipher *tfm);
int (*init)(struct crypto_akcipher *tfm);
void (*exit)(struct crypto_akcipher *tfm);
unsigned int reqsize;
struct crypto_alg base;
};
/**
* DOC: Generic Public Key API
*
* The Public Key API is used with the algorithms of type
* CRYPTO_ALG_TYPE_AKCIPHER (listed as type "akcipher" in /proc/crypto)
*/
/**
* crypto_alloc_akcipher() - allocate AKCIPHER tfm handle
* @alg_name: is the cra_name / name or cra_driver_name / driver name of the
* public key algorithm e.g. "rsa"
* @type: specifies the type of the algorithm
* @mask: specifies the mask for the algorithm
*
* Allocate a handle for public key algorithm. The returned struct
* crypto_akcipher is the handle that is required for any subsequent
* API invocation for the public key operations.
*
* Return: allocated handle in case of success; IS_ERR() is true in case
* of an error, PTR_ERR() returns the error code.
*/
struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
u32 mask);
static inline struct crypto_tfm *crypto_akcipher_tfm(
struct crypto_akcipher *tfm)
{
return &tfm->base;
}
static inline struct akcipher_alg *__crypto_akcipher_alg(struct crypto_alg *alg)
{
return container_of(alg, struct akcipher_alg, base);
}
static inline struct crypto_akcipher *__crypto_akcipher_tfm(
struct crypto_tfm *tfm)
{
return container_of(tfm, struct crypto_akcipher, base);
}
static inline struct akcipher_alg *crypto_akcipher_alg(
struct crypto_akcipher *tfm)
{
return __crypto_akcipher_alg(crypto_akcipher_tfm(tfm)->__crt_alg);
}
static inline unsigned int crypto_akcipher_reqsize(struct crypto_akcipher *tfm)
{
return crypto_akcipher_alg(tfm)->reqsize;
}
static inline void akcipher_request_set_tfm(struct akcipher_request *req,
struct crypto_akcipher *tfm)
{
req->base.tfm = crypto_akcipher_tfm(tfm);
}
static inline struct crypto_akcipher *crypto_akcipher_reqtfm(
struct akcipher_request *req)
{
return __crypto_akcipher_tfm(req->base.tfm);
}
/**
* crypto_free_akcipher() - free AKCIPHER tfm handle
*
* @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
*/
static inline void crypto_free_akcipher(struct crypto_akcipher *tfm)
{
crypto_destroy_tfm(tfm, crypto_akcipher_tfm(tfm));
}
/**
* akcipher_request_alloc() - allocates public key request
*
* @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
* @gfp: allocation flags
*
* Return: allocated handle in case of success or NULL in case of an error.
*/
static inline struct akcipher_request *akcipher_request_alloc(
struct crypto_akcipher *tfm, gfp_t gfp)
{
struct akcipher_request *req;
req = kmalloc(sizeof(*req) + crypto_akcipher_reqsize(tfm), gfp);
if (likely(req))
akcipher_request_set_tfm(req, tfm);
return req;
}
/**
* akcipher_request_free() - zeroize and free public key request
*
* @req: request to free
*/
static inline void akcipher_request_free(struct akcipher_request *req)
{
kfree_sensitive(req);
}
/**
* akcipher_request_set_callback() - Sets an asynchronous callback.
*
* Callback will be called when an asynchronous operation on a given
* request is finished.
*
* @req: request that the callback will be set for
* @flgs: specify for instance if the operation may backlog
* @cmpl: callback which will be called
* @data: private data used by the caller
*/
static inline void akcipher_request_set_callback(struct akcipher_request *req,
u32 flgs,
crypto_completion_t cmpl,
void *data)
{
req->base.complete = cmpl;
req->base.data = data;
req->base.flags = flgs;
}
/**
* akcipher_request_set_crypt() - Sets request parameters
*
* Sets parameters required by crypto operation
*
* @req: public key request
* @src: ptr to input scatter list
* @dst: ptr to output scatter list or NULL for verify op
* @src_len: size of the src input scatter list to be processed
* @dst_len: size of the dst output scatter list or size of signature
* portion in @src for verify op
*/
static inline void akcipher_request_set_crypt(struct akcipher_request *req,
struct scatterlist *src,
struct scatterlist *dst,
unsigned int src_len,
unsigned int dst_len)
{
req->src = src;
req->dst = dst;
req->src_len = src_len;
req->dst_len = dst_len;
}
/**
* crypto_akcipher_maxsize() - Get len for output buffer
*
* Function returns the dest buffer size required for a given key.
* Function assumes that the key is already set in the transformation. If this
* function is called without a setkey or with a failed setkey, you will end up
* in a NULL dereference.
*
* @tfm: AKCIPHER tfm handle allocated with crypto_alloc_akcipher()
*/
static inline unsigned int crypto_akcipher_maxsize(struct crypto_akcipher *tfm)
{
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
return alg->max_size(tfm);
}
/**
* crypto_akcipher_encrypt() - Invoke public key encrypt operation
*
* Function invokes the specific public key encrypt operation for a given
* public key algorithm
*
* @req: asymmetric key request
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_akcipher_encrypt(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
struct crypto_alg *calg = tfm->base.__crt_alg;
unsigned int src_len = req->src_len;
int ret;
crypto_stats_get(calg);
ret = alg->encrypt(req);
crypto_stats_akcipher_encrypt(src_len, ret, calg);
return ret;
}
/**
* crypto_akcipher_decrypt() - Invoke public key decrypt operation
*
* Function invokes the specific public key decrypt operation for a given
* public key algorithm
*
* @req: asymmetric key request
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_akcipher_decrypt(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
struct crypto_alg *calg = tfm->base.__crt_alg;
unsigned int src_len = req->src_len;
int ret;
crypto_stats_get(calg);
ret = alg->decrypt(req);
crypto_stats_akcipher_decrypt(src_len, ret, calg);
return ret;
}
/**
* crypto_akcipher_sign() - Invoke public key sign operation
*
* Function invokes the specific public key sign operation for a given
* public key algorithm
*
* @req: asymmetric key request
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_akcipher_sign(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
struct crypto_alg *calg = tfm->base.__crt_alg;
int ret;
crypto_stats_get(calg);
ret = alg->sign(req);
crypto_stats_akcipher_sign(ret, calg);
return ret;
}
/**
* crypto_akcipher_verify() - Invoke public key signature verification
*
* Function invokes the specific public key signature verification operation
* for a given public key algorithm.
*
* @req: asymmetric key request
*
* Note: req->dst should be NULL, req->src should point to SG of size
* (req->src_size + req->dst_size), containing signature (of req->src_size
* length) with appended digest (of req->dst_size length).
*
* Return: zero on verification success; error code in case of error.
*/
static inline int crypto_akcipher_verify(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
struct crypto_alg *calg = tfm->base.__crt_alg;
int ret;
crypto_stats_get(calg);
ret = alg->verify(req);
crypto_stats_akcipher_verify(ret, calg);
return ret;
}
/**
* crypto_akcipher_set_pub_key() - Invoke set public key operation
*
* Function invokes the algorithm specific set key function, which knows
* how to decode and interpret the encoded key and parameters
*
* @tfm: tfm handle
* @key: BER encoded public key, algo OID, paramlen, BER encoded
* parameters
* @keylen: length of the key (not including other data)
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_akcipher_set_pub_key(struct crypto_akcipher *tfm,
const void *key,
unsigned int keylen)
{
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
return alg->set_pub_key(tfm, key, keylen);
}
/**
* crypto_akcipher_set_priv_key() - Invoke set private key operation
*
* Function invokes the algorithm specific set key function, which knows
* how to decode and interpret the encoded key and parameters
*
* @tfm: tfm handle
* @key: BER encoded private key, algo OID, paramlen, BER encoded
* parameters
* @keylen: length of the key (not including other data)
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_akcipher_set_priv_key(struct crypto_akcipher *tfm,
const void *key,
unsigned int keylen)
{
struct akcipher_alg *alg = crypto_akcipher_alg(tfm);
return alg->set_priv_key(tfm, key, keylen);
}
#endif