/*
* Public Key Encryption
*
* Copyright (c) 2015, Intel Corporation
* Authors: Tadeusz Struk <tadeusz.struk@intel.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.
*
*/
#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
* @set_priv_key: Function invokes the algorithm specific set private key
* function, which knows how to decode and interpret
* the BER encoded private key
* @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)
{
kzfree(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
*
* @tfm: tfm handle
* @key: BER encoded public key
* @keylen: length of the key
*
* 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
*
* @tfm: tfm handle
* @key: BER encoded private key
* @keylen: length of the key
*
* 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
