/* * Key-agreement Protocol Primitives (KPP) * * Copyright (c) 2016, Intel Corporation * Authors: Salvatore Benedetto <salvatore.benedetto@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_KPP_#define _CRYPTO_KPP_#include <linux/crypto.h> /** * struct kpp_request * * @base:	Common attributes for async crypto requests * @src:	Source data * @dst:	Destination data * @src_len:	Size of the input buffer * @dst_len:	Size of the output buffer. 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. * @__ctx:	Start of private context data */struct kpp_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_kpp - user-instantiated object which encapsulate * algorithms and core processing logic * * @base:	Common crypto API algorithm data structure */struct crypto_kpp {	struct crypto_tfm base;}; /** * struct kpp_alg - generic key-agreement protocol primitives * * @set_secret:		Function invokes the protocol specific function to *			store the secret private key along with parameters. *			The implementation knows how to decode the buffer * @generate_public_key: Function generate the public key to be sent to the *			counterpart. In case of error, where output is not big *			enough req->dst_len will be updated to the size *			required * @compute_shared_secret: Function compute the shared secret as defined by *			the algorithm. The result is given back to the user. *			In case of error, where output is not big enough, *			req->dst_len will be updated to the size required * @max_size:		Function returns the size of the output buffer * @init:		Initialize the object. This is called only once at *			instantiation time. In case the cryptographic hardware *			needs to be initialized. Software fallback should be *			put in place here. * @exit:		Undo everything @init did. * * @reqsize:		Request context size required by algorithm *			implementation * @base:		Common crypto API algorithm data structure */struct kpp_alg {	int (*set_secret)(struct crypto_kpp *tfm, const void *buffer,			  unsigned int len);	int (*generate_public_key)(struct kpp_request *req);	int (*compute_shared_secret)(struct kpp_request *req); 	unsigned int (*max_size)(struct crypto_kpp *tfm); 	int (*init)(struct crypto_kpp *tfm);	void (*exit)(struct crypto_kpp *tfm); 	unsigned int reqsize;	struct crypto_alg base;}; /** * DOC: Generic Key-agreement Protocol Primitives API * * The KPP API is used with the algorithm type * CRYPTO_ALG_TYPE_KPP (listed as type "kpp" in /proc/crypto) */ /** * crypto_alloc_kpp() - allocate KPP tfm handle * @alg_name: is the name of the kpp algorithm (e.g. "dh", "ecdh") * @type: specifies the type of the algorithm * @mask: specifies the mask for the algorithm * * Allocate a handle for kpp algorithm. The returned struct crypto_kpp * is required for any following API invocation * * Return: allocated handle in case of success; IS_ERR() is true in case of *	   an error, PTR_ERR() returns the error code. */struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask); static inline struct crypto_tfm *crypto_kpp_tfm(struct crypto_kpp *tfm){	return &tfm->base;} static inline struct kpp_alg *__crypto_kpp_alg(struct crypto_alg *alg){	return container_of(alg, struct kpp_alg, base);} static inline struct crypto_kpp *__crypto_kpp_tfm(struct crypto_tfm *tfm){	return container_of(tfm, struct crypto_kpp, base);} static inline struct kpp_alg *crypto_kpp_alg(struct crypto_kpp *tfm){	return __crypto_kpp_alg(crypto_kpp_tfm(tfm)->__crt_alg);} static inline unsigned int crypto_kpp_reqsize(struct crypto_kpp *tfm){	return crypto_kpp_alg(tfm)->reqsize;} static inline void kpp_request_set_tfm(struct kpp_request *req,				       struct crypto_kpp *tfm){	req->base.tfm = crypto_kpp_tfm(tfm);} static inline struct crypto_kpp *crypto_kpp_reqtfm(struct kpp_request *req){	return __crypto_kpp_tfm(req->base.tfm);} /** * crypto_free_kpp() - free KPP tfm handle * * @tfm: KPP tfm handle allocated with crypto_alloc_kpp() */static inline void crypto_free_kpp(struct crypto_kpp *tfm){	crypto_destroy_tfm(tfm, crypto_kpp_tfm(tfm));} /** * kpp_request_alloc() - allocates kpp request * * @tfm:	KPP tfm handle allocated with crypto_alloc_kpp() * @gfp:	allocation flags * * Return: allocated handle in case of success or NULL in case of an error. */static inline struct kpp_request *kpp_request_alloc(struct crypto_kpp *tfm,						    gfp_t gfp){	struct kpp_request *req; 	req = kmalloc(sizeof(*req) + crypto_kpp_reqsize(tfm), gfp);	if (likely(req))		kpp_request_set_tfm(req, tfm); 	return req;} /** * kpp_request_free() - zeroize and free kpp request * * @req:	request to free */static inline void kpp_request_free(struct kpp_request *req){	kzfree(req);} /** * kpp_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 kpp_request_set_callback(struct kpp_request *req,					    u32 flgs,					    crypto_completion_t cmpl,					    void *data){	req->base.complete = cmpl;	req->base.data = data;	req->base.flags = flgs;} /** * kpp_request_set_input() - Sets input buffer * * Sets parameters required by generate_public_key * * @req:	kpp request * @input:	ptr to input scatter list * @input_len:	size of the input scatter list */static inline void kpp_request_set_input(struct kpp_request *req,					 struct scatterlist *input,					 unsigned int input_len){	req->src = input;	req->src_len = input_len;} /** * kpp_request_set_output() - Sets output buffer * * Sets parameters required by kpp operation * * @req:	kpp request * @output:	ptr to output scatter list * @output_len:	size of the output scatter list */static inline void kpp_request_set_output(struct kpp_request *req,					  struct scatterlist *output,					  unsigned int output_len){	req->dst = output;	req->dst_len = output_len;} enum {	CRYPTO_KPP_SECRET_TYPE_UNKNOWN,	CRYPTO_KPP_SECRET_TYPE_DH,	CRYPTO_KPP_SECRET_TYPE_ECDH,}; /** * struct kpp_secret - small header for packing secret buffer * * @type:	define type of secret. Each kpp type will define its own * @len:	specify the len of the secret, include the header, that *		follows the struct */struct kpp_secret {	unsigned short type;	unsigned short len;}; /** * crypto_kpp_set_secret() - Invoke kpp operation * * Function invokes the specific kpp operation for a given alg. * * @tfm:	tfm handle * @buffer:	Buffer holding the packet representation of the private *		key. The structure of the packet key depends on the particular *		KPP implementation. Packing and unpacking helpers are provided *		for ECDH and DH (see the respective header files for those *		implementations). * @len:	Length of the packet private key buffer. * * Return: zero on success; error code in case of error */static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm,					const void *buffer, unsigned int len){	struct kpp_alg *alg = crypto_kpp_alg(tfm); 	return alg->set_secret(tfm, buffer, len);} /** * crypto_kpp_generate_public_key() - Invoke kpp operation * * Function invokes the specific kpp operation for generating the public part * for a given kpp algorithm. * * To generate a private key, the caller should use a random number generator. * The output of the requested length serves as the private key. * * @req:	kpp key request * * Return: zero on success; error code in case of error */static inline int crypto_kpp_generate_public_key(struct kpp_request *req){	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);	struct kpp_alg *alg = crypto_kpp_alg(tfm); 	return alg->generate_public_key(req);} /** * crypto_kpp_compute_shared_secret() - Invoke kpp operation * * Function invokes the specific kpp operation for computing the shared secret * for a given kpp algorithm. * * @req:	kpp key request * * Return: zero on success; error code in case of error */static inline int crypto_kpp_compute_shared_secret(struct kpp_request *req){	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);	struct kpp_alg *alg = crypto_kpp_alg(tfm); 	return alg->compute_shared_secret(req);} /** * crypto_kpp_maxsize() - Get len for output buffer * * Function returns the output 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:	KPP tfm handle allocated with crypto_alloc_kpp() */static inline unsigned int crypto_kpp_maxsize(struct crypto_kpp *tfm){	struct kpp_alg *alg = crypto_kpp_alg(tfm); 	return alg->max_size(tfm);} #endif