diff mbox

[v8,1/3] crypto: Key-agreement Protocol Primitives API (KPP)

Message ID 1465854948-9084-2-git-send-email-salvatore.benedetto@intel.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show

Commit Message

Salvatore Benedetto June 13, 2016, 9:55 p.m. UTC
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>
---
 crypto/Kconfig                  |  10 ++
 crypto/Makefile                 |   1 +
 crypto/crypto_user.c            |  20 +++
 crypto/kpp.c                    | 123 ++++++++++++++++
 include/crypto/internal/kpp.h   |  64 +++++++++
 include/crypto/kpp.h            | 310 ++++++++++++++++++++++++++++++++++++++++
 include/linux/crypto.h          |   1 +
 include/uapi/linux/cryptouser.h |   5 +
 8 files changed, 534 insertions(+)
 create mode 100644 crypto/kpp.c
 create mode 100644 include/crypto/internal/kpp.h
 create mode 100644 include/crypto/kpp.h

Comments

Herbert Xu June 14, 2016, 11:34 a.m. UTC | #1
On Mon, Jun 13, 2016 at 10:55:46PM +0100, Salvatore Benedetto wrote:
>
> +struct kpp_alg {
> +	int (*set_secret)(struct crypto_kpp *tfm, void *buffer);

Sorry I think we need to change this.  Leaving this with no type
checking between the user and the driver is a recipe for disaster.

I think the easiest solution is to use either BER encoding like
rsa.c or netlink encoding like authenc.c.

Cheers,
Salvatore Benedetto June 14, 2016, 2:36 p.m. UTC | #2
> -----Original Message-----
> From: Herbert Xu [mailto:herbert@gondor.apana.org.au]
> Sent: Tuesday, June 14, 2016 12:35 PM
> To: Benedetto, Salvatore <salvatore.benedetto@intel.com>
> Cc: linux-crypto@vger.kernel.org
> Subject: Re: [PATCH v8 1/3] crypto: Key-agreement Protocol Primitives API
> (KPP)
> 
> On Mon, Jun 13, 2016 at 10:55:46PM +0100, Salvatore Benedetto wrote:
> >
> > +struct kpp_alg {
> > +	int (*set_secret)(struct crypto_kpp *tfm, void *buffer);
> 
> Sorry I think we need to change this.  Leaving this with no type checking
> between the user and the driver is a recipe for disaster.
> 
> I think the easiest solution is to use either BER encoding like rsa.c or netlink
> encoding like authenc.c.
>

My very first patch used PKCS3 and there were some objections to that.
https://patchwork.kernel.org/patch/8311881/
 
Both Bluetooth or keyctl KEYCTL_DH_COMPUTE would have to first pack the
key to whatever format we choose and I don't see that very convinient. We
only want to provide the acceleration here, without bounding the user to a
certain key format.
 
 akcipher is different as PKCS1 is a recognized standard for RSA keys.
 
 Please don't get me wrong, it's not much of an issue for me to respin the
 patchset and change that to PKCS3 for example, but I see no harm in leaving
 it as it is and moving the key check format to whatever upper layer is using us
 (like BT and keyctl). Just more work for who is using the API.
 
 Could you reconsider that?
 
 Thanks,
 Salvatore
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Herbert Xu June 15, 2016, 9:41 a.m. UTC | #3
On Tue, Jun 14, 2016 at 02:36:54PM +0000, Benedetto, Salvatore wrote:
>
> My very first patch used PKCS3 and there were some objections to that.
> https://patchwork.kernel.org/patch/8311881/
>  
> Both Bluetooth or keyctl KEYCTL_DH_COMPUTE would have to first pack the
> key to whatever format we choose and I don't see that very convinient. We
> only want to provide the acceleration here, without bounding the user to a
> certain key format.

Have you looked at the rtnetlink encoding used by authenc.c? It is
much more light-weight.  There is no need to depend on ASN.1 parsers
at all.

To make it even easier for users such as bluetooth, you can create
helpers that convert struct dh to a byte stream, and vice versa.
For example, the interface could look like this:

	struct dh key;
	char *buf;
	unsigned int len;

	/* init key */
	key = ...;

	len = crypto_dh_key_len(&key);

	buf = kmalloc(len, GFP_KERNEL);
	if (!buf)
		...;

	crypto_dh_encode_key(buf, len, &key);
	crypto_kpp_set_secret(tfm, buf, len);

The driver would do:

set_secret(char *buf, unsigned int len)
{
	struct dh key;
	int err;

	err = crypto_dh_decode_key(buf, len, &key);
	...

>  akcipher is different as PKCS1 is a recognized standard for RSA keys.
>  
>  Please don't get me wrong, it's not much of an issue for me to respin the
>  patchset and change that to PKCS3 for example, but I see no harm in leaving
>  it as it is and moving the key check format to whatever upper layer is using us
>  (like BT and keyctl). Just more work for who is using the API.
>  
>  Could you reconsider that?

I'm sorry but using a void * for this is not acceptable.  We're
talking about a data structure that comes from arbitrary users
and then has to be decoded by random drivers.  It's something
totally different compared to a limited environment where the
same author is writing the code that creates and consumes the
pointer.

Throwing random void pointers at drivers is not a good idea.

Thanks,
diff mbox

Patch

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 1d33beb..0bd6d7f 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -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"
diff --git a/crypto/Makefile b/crypto/Makefile
index 4f4ef7e..5b60890 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -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
diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index f71960d..e7a0a9d 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -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:
diff --git a/crypto/kpp.c b/crypto/kpp.c
new file mode 100644
index 0000000..d36ce05
--- /dev/null
+++ b/crypto/kpp.c
@@ -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");
diff --git a/include/crypto/internal/kpp.h b/include/crypto/internal/kpp.h
new file mode 100644
index 0000000..ad3acf3
--- /dev/null
+++ b/include/crypto/internal/kpp.h
@@ -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
diff --git a/include/crypto/kpp.h b/include/crypto/kpp.h
new file mode 100644
index 0000000..90436d0
--- /dev/null
+++ b/include/crypto/kpp.h
@@ -0,0 +1,310 @@ 
+/*
+ * 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);
+	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;
+}
+
+/**
+ * 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)
+{
+	struct kpp_alg *alg = crypto_kpp_alg(tfm);
+
+	return alg->set_secret(tfm, buffer);
+}
+
+/**
+ * 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
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index d844cbc..992cfc2 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -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
diff --git a/include/uapi/linux/cryptouser.h b/include/uapi/linux/cryptouser.h
index 2e67bb6..79b5ded 100644
--- a/include/uapi/linux/cryptouser.h
+++ b/include/uapi/linux/cryptouser.h
@@ -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))