Commit 802c7f1c authored by Salvatore Benedetto's avatar Salvatore Benedetto Committed by Herbert Xu

crypto: dh - Add DH software implementation

* Implement MPI based Diffie-Hellman under kpp API
 * Test provided uses data generad by OpenSSL
Signed-off-by: default avatarSalvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 4e5f2c40
......@@ -111,6 +111,14 @@ config CRYPTO_RSA
help
Generic implementation of the RSA public key algorithm.
config CRYPTO_DH
tristate "Diffie-Hellman algorithm"
select CRYPTO_KPP
select MPILIB
help
Generic implementation of the Diffie-Hellman algorithm.
config CRYPTO_MANAGER
tristate "Cryptographic algorithm manager"
select CRYPTO_MANAGER2
......
......@@ -32,6 +32,10 @@ obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
obj-$(CONFIG_CRYPTO_AKCIPHER2) += akcipher.o
obj-$(CONFIG_CRYPTO_KPP2) += kpp.o
dh_generic-y := dh.o
dh_generic-y += dh_helper.o
obj-$(CONFIG_CRYPTO_DH) += dh_generic.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
clean-files += rsapubkey-asn1.c rsapubkey-asn1.h
......
/* Diffie-Hellman Key Agreement Method [RFC2631]
*
* 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/module.h>
#include <crypto/internal/kpp.h>
#include <crypto/kpp.h>
#include <crypto/dh.h>
#include <linux/mpi.h>
struct dh_ctx {
MPI p;
MPI g;
MPI xa;
};
static inline void dh_clear_params(struct dh_ctx *ctx)
{
mpi_free(ctx->p);
mpi_free(ctx->g);
ctx->p = NULL;
ctx->g = NULL;
}
static void dh_free_ctx(struct dh_ctx *ctx)
{
dh_clear_params(ctx);
mpi_free(ctx->xa);
ctx->xa = NULL;
}
/*
* If base is g we compute the public key
* ya = g^xa mod p; [RFC2631 sec 2.1.1]
* else if base if the counterpart public key we compute the shared secret
* ZZ = yb^xa mod p; [RFC2631 sec 2.1.1]
*/
static int _compute_val(const struct dh_ctx *ctx, MPI base, MPI val)
{
/* val = base^xa mod p */
return mpi_powm(val, base, ctx->xa, ctx->p);
}
static inline struct dh_ctx *dh_get_ctx(struct crypto_kpp *tfm)
{
return kpp_tfm_ctx(tfm);
}
static int dh_check_params_length(unsigned int p_len)
{
return (p_len < 1536) ? -EINVAL : 0;
}
static int dh_set_params(struct dh_ctx *ctx, struct dh *params)
{
if (unlikely(!params->p || !params->g))
return -EINVAL;
if (dh_check_params_length(params->p_size << 3))
return -EINVAL;
ctx->p = mpi_read_raw_data(params->p, params->p_size);
if (!ctx->p)
return -EINVAL;
ctx->g = mpi_read_raw_data(params->g, params->g_size);
if (!ctx->g) {
mpi_free(ctx->p);
return -EINVAL;
}
return 0;
}
static int dh_set_secret(struct crypto_kpp *tfm, void *buf, unsigned int len)
{
struct dh_ctx *ctx = dh_get_ctx(tfm);
struct dh params;
if (crypto_dh_decode_key(buf, len, &params) < 0)
return -EINVAL;
if (dh_set_params(ctx, &params) < 0)
return -EINVAL;
ctx->xa = mpi_read_raw_data(params.key, params.key_size);
if (!ctx->xa) {
dh_clear_params(ctx);
return -EINVAL;
}
return 0;
}
static int dh_compute_value(struct kpp_request *req)
{
struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
struct dh_ctx *ctx = dh_get_ctx(tfm);
MPI base, val = mpi_alloc(0);
int ret = 0;
int sign;
if (!val)
return -ENOMEM;
if (unlikely(!ctx->xa)) {
ret = -EINVAL;
goto err_free_val;
}
if (req->src) {
base = mpi_read_raw_from_sgl(req->src, req->src_len);
if (!base) {
ret = EINVAL;
goto err_free_val;
}
} else {
base = ctx->g;
}
ret = _compute_val(ctx, base, val);
if (ret)
goto err_free_base;
ret = mpi_write_to_sgl(val, req->dst, &req->dst_len, &sign);
if (ret)
goto err_free_base;
if (sign < 0)
ret = -EBADMSG;
err_free_base:
if (req->src)
mpi_free(base);
err_free_val:
mpi_free(val);
return ret;
}
static int dh_max_size(struct crypto_kpp *tfm)
{
struct dh_ctx *ctx = dh_get_ctx(tfm);
return mpi_get_size(ctx->p);
}
static void dh_exit_tfm(struct crypto_kpp *tfm)
{
struct dh_ctx *ctx = dh_get_ctx(tfm);
dh_free_ctx(ctx);
}
static struct kpp_alg dh = {
.set_secret = dh_set_secret,
.generate_public_key = dh_compute_value,
.compute_shared_secret = dh_compute_value,
.max_size = dh_max_size,
.exit = dh_exit_tfm,
.base = {
.cra_name = "dh",
.cra_driver_name = "dh-generic",
.cra_priority = 100,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct dh_ctx),
},
};
static int dh_init(void)
{
return crypto_register_kpp(&dh);
}
static void dh_exit(void)
{
crypto_unregister_kpp(&dh);
}
module_init(dh_init);
module_exit(dh_exit);
MODULE_ALIAS_CRYPTO("dh");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("DH generic algorithm");
/*
* 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/string.h>
#include <crypto/dh.h>
#include <crypto/kpp.h>
#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))
static inline u8 *dh_pack_data(void *dst, const void *src, size_t size)
{
memcpy(dst, src, size);
return dst + size;
}
static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size)
{
memcpy(dst, src, size);
return src + size;
}
static inline int dh_data_size(const struct dh *p)
{
return p->key_size + p->p_size + p->g_size;
}
int crypto_dh_key_len(const struct dh *p)
{
return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
}
EXPORT_SYMBOL_GPL(crypto_dh_key_len);
int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
{
u8 *ptr = buf;
struct kpp_secret secret = {
.type = CRYPTO_KPP_SECRET_TYPE_DH,
.len = len
};
if (unlikely(!buf))
return -EINVAL;
if (len != crypto_dh_key_len(params))
return -EINVAL;
ptr = dh_pack_data(ptr, &secret, sizeof(secret));
ptr = dh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
ptr = dh_pack_data(ptr, &params->p_size, sizeof(params->p_size));
ptr = dh_pack_data(ptr, &params->g_size, sizeof(params->g_size));
ptr = dh_pack_data(ptr, params->key, params->key_size);
ptr = dh_pack_data(ptr, params->p, params->p_size);
dh_pack_data(ptr, params->g, params->g_size);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
{
const u8 *ptr = buf;
struct kpp_secret secret;
if (unlikely(!buf || len < DH_KPP_SECRET_MIN_SIZE))
return -EINVAL;
ptr = dh_unpack_data(&secret, ptr, sizeof(secret));
if (secret.type != CRYPTO_KPP_SECRET_TYPE_DH)
return -EINVAL;
ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
if (secret.len != crypto_dh_key_len(params))
return -EINVAL;
/* Don't allocate memory. Set pointers to data within
* the given buffer
*/
params->key = (void *)ptr;
params->p = (void *)(ptr + params->key_size);
params->g = (void *)(ptr + params->key_size + params->p_size);
return 0;
}
EXPORT_SYMBOL_GPL(crypto_dh_decode_key);
......@@ -32,6 +32,7 @@
#include <crypto/rng.h>
#include <crypto/drbg.h>
#include <crypto/akcipher.h>
#include <crypto/kpp.h>
#include "internal.h"
......@@ -120,6 +121,11 @@ struct akcipher_test_suite {
unsigned int count;
};
struct kpp_test_suite {
struct kpp_testvec *vecs;
unsigned int count;
};
struct alg_test_desc {
const char *alg;
int (*test)(const struct alg_test_desc *desc, const char *driver,
......@@ -134,6 +140,7 @@ struct alg_test_desc {
struct cprng_test_suite cprng;
struct drbg_test_suite drbg;
struct akcipher_test_suite akcipher;
struct kpp_test_suite kpp;
} suite;
};
......@@ -1777,6 +1784,133 @@ static int alg_test_drbg(const struct alg_test_desc *desc, const char *driver,
}
static int do_test_kpp(struct crypto_kpp *tfm, struct kpp_testvec *vec,
const char *alg)
{
struct kpp_request *req;
void *input_buf = NULL;
void *output_buf = NULL;
struct tcrypt_result result;
unsigned int out_len_max;
int err = -ENOMEM;
struct scatterlist src, dst;
req = kpp_request_alloc(tfm, GFP_KERNEL);
if (!req)
return err;
init_completion(&result.completion);
err = crypto_kpp_set_secret(tfm, vec->secret, vec->secret_size);
if (err < 0)
goto free_req;
out_len_max = crypto_kpp_maxsize(tfm);
output_buf = kzalloc(out_len_max, GFP_KERNEL);
if (!output_buf) {
err = -ENOMEM;
goto free_req;
}
/* Use appropriate parameter as base */
kpp_request_set_input(req, NULL, 0);
sg_init_one(&dst, output_buf, out_len_max);
kpp_request_set_output(req, &dst, out_len_max);
kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);
/* Compute public key */
err = wait_async_op(&result, crypto_kpp_generate_public_key(req));
if (err) {
pr_err("alg: %s: generate public key test failed. err %d\n",
alg, err);
goto free_output;
}
/* Verify calculated public key */
if (memcmp(vec->expected_a_public, sg_virt(req->dst),
vec->expected_a_public_size)) {
pr_err("alg: %s: generate public key test failed. Invalid output\n",
alg);
err = -EINVAL;
goto free_output;
}
/* Calculate shared secret key by using counter part (b) public key. */
input_buf = kzalloc(vec->b_public_size, GFP_KERNEL);
if (!input_buf) {
err = -ENOMEM;
goto free_output;
}
memcpy(input_buf, vec->b_public, vec->b_public_size);
sg_init_one(&src, input_buf, vec->b_public_size);
sg_init_one(&dst, output_buf, out_len_max);
kpp_request_set_input(req, &src, vec->b_public_size);
kpp_request_set_output(req, &dst, out_len_max);
kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
tcrypt_complete, &result);
err = wait_async_op(&result, crypto_kpp_compute_shared_secret(req));
if (err) {
pr_err("alg: %s: compute shard secret test failed. err %d\n",
alg, err);
goto free_all;
}
/*
* verify shared secret from which the user will derive
* secret key by executing whatever hash it has chosen
*/
if (memcmp(vec->expected_ss, sg_virt(req->dst),
vec->expected_ss_size)) {
pr_err("alg: %s: compute shared secret test failed. Invalid output\n",
alg);
err = -EINVAL;
}
free_all:
kfree(input_buf);
free_output:
kfree(output_buf);
free_req:
kpp_request_free(req);
return err;
}
static int test_kpp(struct crypto_kpp *tfm, const char *alg,
struct kpp_testvec *vecs, unsigned int tcount)
{
int ret, i;
for (i = 0; i < tcount; i++) {
ret = do_test_kpp(tfm, vecs++, alg);
if (ret) {
pr_err("alg: %s: test failed on vector %d, err=%d\n",
alg, i + 1, ret);
return ret;
}
}
return 0;
}
static int alg_test_kpp(const struct alg_test_desc *desc, const char *driver,
u32 type, u32 mask)
{
struct crypto_kpp *tfm;
int err = 0;
tfm = crypto_alloc_kpp(driver, type | CRYPTO_ALG_INTERNAL, mask);
if (IS_ERR(tfm)) {
pr_err("alg: kpp: Failed to load tfm for %s: %ld\n",
driver, PTR_ERR(tfm));
return PTR_ERR(tfm);
}
if (desc->suite.kpp.vecs)
err = test_kpp(tfm, desc->alg, desc->suite.kpp.vecs,
desc->suite.kpp.count);
crypto_free_kpp(tfm);
return err;
}
static int do_test_rsa(struct crypto_akcipher *tfm,
struct akcipher_testvec *vecs)
{
......@@ -2728,6 +2862,16 @@ static const struct alg_test_desc alg_test_descs[] = {
}
}
}
}, {
.alg = "dh",
.test = alg_test_kpp,
.fips_allowed = 1,
.suite = {
.kpp = {
.vecs = dh_tv_template,
.count = DH_TEST_VECTORS
}
}
}, {
.alg = "digest_null",
.test = alg_test_null,
......
This diff is collapsed.
/*
* Diffie-Hellman secret to be used with kpp API along with helper functions
*
* 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_DH_
#define _CRYPTO_DH_
struct dh {
void *key;
void *p;
void *g;
unsigned int key_size;
unsigned int p_size;
unsigned int g_size;
};
int crypto_dh_key_len(const struct dh *params);
int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params);
int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params);
#endif
......@@ -242,6 +242,7 @@ static inline void kpp_request_set_output(struct kpp_request *req,
enum {
CRYPTO_KPP_SECRET_TYPE_UNKNOWN,
CRYPTO_KPP_SECRET_TYPE_DH,
};
/**
......
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