crypto: kpp - Key-agreement Protocol Primitives API (KPP)

Add key-agreement protocol primitives (kpp) API which allows to
implement primitives required by protocols such as DH and ECDH.
The API is composed mainly by the following functions
 * set_secret() - It allows the user to set his secret, also
   referred to as his private key, along with the parameters
   known to both parties involved in the key-agreement session.
 * generate_public_key() - It generates the public key to be sent to
   the other counterpart involved in the key-agreement session. The
   function has to be called after set_params() and set_secret()
 * generate_secret() - It generates the shared secret for the session

Other functions such as init() and exit() are provided for allowing
cryptographic hardware to be inizialized properly before use

Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Salvatore Benedetto 2016-06-22 17:49:13 +01:00 committed by Herbert Xu
parent 331bf739c4
commit 4e5f2c4007
8 changed files with 552 additions and 0 deletions

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@ -93,6 +93,15 @@ config CRYPTO_AKCIPHER
select CRYPTO_AKCIPHER2
select CRYPTO_ALGAPI
config CRYPTO_KPP2
tristate
select CRYPTO_ALGAPI2
config CRYPTO_KPP
tristate
select CRYPTO_ALGAPI
select CRYPTO_KPP2
config CRYPTO_RSA
tristate "RSA algorithm"
select CRYPTO_AKCIPHER
@ -115,6 +124,7 @@ config CRYPTO_MANAGER2
select CRYPTO_HASH2
select CRYPTO_BLKCIPHER2
select CRYPTO_AKCIPHER2
select CRYPTO_KPP2
config CRYPTO_USER
tristate "Userspace cryptographic algorithm configuration"

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@ -30,6 +30,7 @@ crypto_hash-y += shash.o
obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
obj-$(CONFIG_CRYPTO_AKCIPHER2) += akcipher.o
obj-$(CONFIG_CRYPTO_KPP2) += kpp.o
$(obj)/rsapubkey-asn1.o: $(obj)/rsapubkey-asn1.c $(obj)/rsapubkey-asn1.h
$(obj)/rsaprivkey-asn1.o: $(obj)/rsaprivkey-asn1.c $(obj)/rsaprivkey-asn1.h

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@ -28,6 +28,7 @@
#include <crypto/internal/skcipher.h>
#include <crypto/internal/rng.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include "internal.h"
@ -126,6 +127,21 @@ nla_put_failure:
return -EMSGSIZE;
}
static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_kpp rkpp;
strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
sizeof(struct crypto_report_kpp), &rkpp))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int crypto_report_one(struct crypto_alg *alg,
struct crypto_user_alg *ualg, struct sk_buff *skb)
{
@ -176,6 +192,10 @@ static int crypto_report_one(struct crypto_alg *alg,
goto nla_put_failure;
break;
case CRYPTO_ALG_TYPE_KPP:
if (crypto_report_kpp(skb, alg))
goto nla_put_failure;
break;
}
out:

123
crypto/kpp.c Normal file
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@ -0,0 +1,123 @@
/*
* 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.
*
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/crypto.h>
#include <crypto/algapi.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include <crypto/kpp.h>
#include <crypto/internal/kpp.h>
#include "internal.h"
#ifdef CONFIG_NET
static int crypto_kpp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
struct crypto_report_kpp rkpp;
strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
sizeof(struct crypto_report_kpp), &rkpp))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
#else
static int crypto_kpp_report(struct sk_buff *skb, struct crypto_alg *alg)
{
return -ENOSYS;
}
#endif
static void crypto_kpp_show(struct seq_file *m, struct crypto_alg *alg)
__attribute__ ((unused));
static void crypto_kpp_show(struct seq_file *m, struct crypto_alg *alg)
{
seq_puts(m, "type : kpp\n");
}
static void crypto_kpp_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_kpp *kpp = __crypto_kpp_tfm(tfm);
struct kpp_alg *alg = crypto_kpp_alg(kpp);
alg->exit(kpp);
}
static int crypto_kpp_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_kpp *kpp = __crypto_kpp_tfm(tfm);
struct kpp_alg *alg = crypto_kpp_alg(kpp);
if (alg->exit)
kpp->base.exit = crypto_kpp_exit_tfm;
if (alg->init)
return alg->init(kpp);
return 0;
}
static const struct crypto_type crypto_kpp_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_kpp_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_kpp_show,
#endif
.report = crypto_kpp_report,
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_MASK,
.type = CRYPTO_ALG_TYPE_KPP,
.tfmsize = offsetof(struct crypto_kpp, base),
};
struct crypto_kpp *crypto_alloc_kpp(const char *alg_name, u32 type, u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_kpp_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_kpp);
static void kpp_prepare_alg(struct kpp_alg *alg)
{
struct crypto_alg *base = &alg->base;
base->cra_type = &crypto_kpp_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_KPP;
}
int crypto_register_kpp(struct kpp_alg *alg)
{
struct crypto_alg *base = &alg->base;
kpp_prepare_alg(alg);
return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_kpp);
void crypto_unregister_kpp(struct kpp_alg *alg)
{
crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_kpp);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Key-agreement Protocol Primitives");

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@ -0,0 +1,64 @@
/*
* 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_INT_H
#define _CRYPTO_KPP_INT_H
#include <crypto/kpp.h>
#include <crypto/algapi.h>
/*
* Transform internal helpers.
*/
static inline void *kpp_request_ctx(struct kpp_request *req)
{
return req->__ctx;
}
static inline void *kpp_tfm_ctx(struct crypto_kpp *tfm)
{
return tfm->base.__crt_ctx;
}
static inline void kpp_request_complete(struct kpp_request *req, int err)
{
req->base.complete(&req->base, err);
}
static inline const char *kpp_alg_name(struct crypto_kpp *tfm)
{
return crypto_kpp_tfm(tfm)->__crt_alg->cra_name;
}
/**
* crypto_register_kpp() -- Register key-agreement protocol primitives algorithm
*
* Function registers an implementation of a key-agreement protocol primitive
* algorithm
*
* @alg: algorithm definition
*
* Return: zero on success; error code in case of error
*/
int crypto_register_kpp(struct kpp_alg *alg);
/**
* crypto_unregister_kpp() -- Unregister key-agreement protocol primitive
* algorithm
*
* Function unregisters an implementation of a key-agreement protocol primitive
* algorithm
*
* @alg: algorithm definition
*/
void crypto_unregister_kpp(struct kpp_alg *alg);
#endif

328
include/crypto/kpp.h Normal file
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@ -0,0 +1,328 @@
/*
* 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 thie 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, void *buffer,
unsigned int len);
int (*generate_public_key)(struct kpp_request *req);
int (*compute_shared_secret)(struct kpp_request *req);
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 Primitevs 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 requeried 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,
};
/**
* 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
*
* Return: zero on success; error code in case of error
*/
static inline int crypto_kpp_set_secret(struct crypto_kpp *tfm, 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
*
* @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
*
* @tfm: KPP tfm handle allocated with crypto_alloc_kpp()
*
* Return: minimum len for output buffer or error code if key hasn't been set
*/
static inline int crypto_kpp_maxsize(struct crypto_kpp *tfm)
{
struct kpp_alg *alg = crypto_kpp_alg(tfm);
return alg->max_size(tfm);
}
#endif

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@ -48,6 +48,7 @@
#define CRYPTO_ALG_TYPE_BLKCIPHER 0x00000004
#define CRYPTO_ALG_TYPE_ABLKCIPHER 0x00000005
#define CRYPTO_ALG_TYPE_GIVCIPHER 0x00000006
#define CRYPTO_ALG_TYPE_KPP 0x00000008
#define CRYPTO_ALG_TYPE_RNG 0x0000000c
#define CRYPTO_ALG_TYPE_AKCIPHER 0x0000000d
#define CRYPTO_ALG_TYPE_DIGEST 0x0000000e

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@ -45,6 +45,7 @@ enum crypto_attr_type_t {
CRYPTOCFGA_REPORT_RNG, /* struct crypto_report_rng */
CRYPTOCFGA_REPORT_CIPHER, /* struct crypto_report_cipher */
CRYPTOCFGA_REPORT_AKCIPHER, /* struct crypto_report_akcipher */
CRYPTOCFGA_REPORT_KPP, /* struct crypto_report_kpp */
__CRYPTOCFGA_MAX
#define CRYPTOCFGA_MAX (__CRYPTOCFGA_MAX - 1)
@ -107,5 +108,9 @@ struct crypto_report_akcipher {
char type[CRYPTO_MAX_NAME];
};
struct crypto_report_kpp {
char type[CRYPTO_MAX_NAME];
};
#define CRYPTO_REPORT_MAXSIZE (sizeof(struct crypto_user_alg) + \
sizeof(struct crypto_report_blkcipher))