Commit cfc2bb32 authored by Tadeusz Struk's avatar Tadeusz Struk Committed by Herbert Xu

crypto: rsa - add a new rsa generic implementation

Add a new rsa generic SW implementation.
This implements only cryptographic primitives.
Signed-off-by: default avatarTadeusz Struk <tadeusz.struk@intel.com>

Added select on ASN1.
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 3c339ab8
......@@ -100,6 +100,14 @@ config CRYPTO_AKCIPHER
select CRYPTO_AKCIPHER2
select CRYPTO_ALGAPI
config CRYPTO_RSA
tristate "RSA algorithm"
select AKCIPHER
select MPILIB
select ASN1
help
Generic implementation of the RSA public key algorithm.
config CRYPTO_MANAGER
tristate "Cryptographic algorithm manager"
select CRYPTO_MANAGER2
......
......@@ -30,6 +30,14 @@ obj-$(CONFIG_CRYPTO_HASH2) += crypto_hash.o
obj-$(CONFIG_CRYPTO_PCOMP2) += pcompress.o
obj-$(CONFIG_CRYPTO_AKCIPHER2) += akcipher.o
$(obj)/rsakey-asn1.o: $(obj)/rsakey-asn1.c $(obj)/rsakey-asn1.h
clean-files += rsakey-asn1.c rsakey-asn1.h
rsa_generic-y := rsakey-asn1.o
rsa_generic-y += rsa.o
rsa_generic-y += rsa_helper.o
obj-$(CONFIG_CRYPTO_RSA) += rsa_generic.o
cryptomgr-y := algboss.o testmgr.o
obj-$(CONFIG_CRYPTO_MANAGER2) += cryptomgr.o
......
/* RSA asymmetric public-key algorithm [RFC3447]
*
* 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 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/rsa.h>
#include <crypto/internal/akcipher.h>
#include <crypto/akcipher.h>
/*
* RSAEP function [RFC3447 sec 5.1.1]
* c = m^e mod n;
*/
static int _rsa_enc(const struct rsa_key *key, MPI c, MPI m)
{
/* (1) Validate 0 <= m < n */
if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
return -EINVAL;
/* (2) c = m^e mod n */
return mpi_powm(c, m, key->e, key->n);
}
/*
* RSADP function [RFC3447 sec 5.1.2]
* m = c^d mod n;
*/
static int _rsa_dec(const struct rsa_key *key, MPI m, MPI c)
{
/* (1) Validate 0 <= c < n */
if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
return -EINVAL;
/* (2) m = c^d mod n */
return mpi_powm(m, c, key->d, key->n);
}
/*
* RSASP1 function [RFC3447 sec 5.2.1]
* s = m^d mod n
*/
static int _rsa_sign(const struct rsa_key *key, MPI s, MPI m)
{
/* (1) Validate 0 <= m < n */
if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
return -EINVAL;
/* (2) s = m^d mod n */
return mpi_powm(s, m, key->d, key->n);
}
/*
* RSAVP1 function [RFC3447 sec 5.2.2]
* m = s^e mod n;
*/
static int _rsa_verify(const struct rsa_key *key, MPI m, MPI s)
{
/* (1) Validate 0 <= s < n */
if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0)
return -EINVAL;
/* (2) m = s^e mod n */
return mpi_powm(m, s, key->e, key->n);
}
static inline struct rsa_key *rsa_get_key(struct crypto_akcipher *tfm)
{
return akcipher_tfm_ctx(tfm);
}
static int rsa_enc(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
const struct rsa_key *pkey = rsa_get_key(tfm);
MPI m, c = mpi_alloc(0);
int ret = 0;
int sign;
if (!c)
return -ENOMEM;
if (unlikely(!pkey->n || !pkey->e)) {
ret = -EINVAL;
goto err_free_c;
}
if (req->dst_len < mpi_get_size(pkey->n)) {
req->dst_len = mpi_get_size(pkey->n);
ret = -EOVERFLOW;
goto err_free_c;
}
m = mpi_read_raw_data(req->src, req->src_len);
if (!m) {
ret = -ENOMEM;
goto err_free_c;
}
ret = _rsa_enc(pkey, c, m);
if (ret)
goto err_free_m;
ret = mpi_read_buffer(c, req->dst, req->dst_len, &req->dst_len, &sign);
if (ret)
goto err_free_m;
if (sign < 0) {
ret = -EBADMSG;
goto err_free_m;
}
err_free_m:
mpi_free(m);
err_free_c:
mpi_free(c);
return ret;
}
static int rsa_dec(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
const struct rsa_key *pkey = rsa_get_key(tfm);
MPI c, m = mpi_alloc(0);
int ret = 0;
int sign;
if (!m)
return -ENOMEM;
if (unlikely(!pkey->n || !pkey->d)) {
ret = -EINVAL;
goto err_free_m;
}
if (req->dst_len < mpi_get_size(pkey->n)) {
req->dst_len = mpi_get_size(pkey->n);
ret = -EOVERFLOW;
goto err_free_m;
}
c = mpi_read_raw_data(req->src, req->src_len);
if (!c) {
ret = -ENOMEM;
goto err_free_m;
}
ret = _rsa_dec(pkey, m, c);
if (ret)
goto err_free_c;
ret = mpi_read_buffer(m, req->dst, req->dst_len, &req->dst_len, &sign);
if (ret)
goto err_free_c;
if (sign < 0) {
ret = -EBADMSG;
goto err_free_c;
}
err_free_c:
mpi_free(c);
err_free_m:
mpi_free(m);
return ret;
}
static int rsa_sign(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
const struct rsa_key *pkey = rsa_get_key(tfm);
MPI m, s = mpi_alloc(0);
int ret = 0;
int sign;
if (!s)
return -ENOMEM;
if (unlikely(!pkey->n || !pkey->d)) {
ret = -EINVAL;
goto err_free_s;
}
if (req->dst_len < mpi_get_size(pkey->n)) {
req->dst_len = mpi_get_size(pkey->n);
ret = -EOVERFLOW;
goto err_free_s;
}
m = mpi_read_raw_data(req->src, req->src_len);
if (!m) {
ret = -ENOMEM;
goto err_free_s;
}
ret = _rsa_sign(pkey, s, m);
if (ret)
goto err_free_m;
ret = mpi_read_buffer(s, req->dst, req->dst_len, &req->dst_len, &sign);
if (ret)
goto err_free_m;
if (sign < 0) {
ret = -EBADMSG;
goto err_free_m;
}
err_free_m:
mpi_free(m);
err_free_s:
mpi_free(s);
return ret;
}
static int rsa_verify(struct akcipher_request *req)
{
struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
const struct rsa_key *pkey = rsa_get_key(tfm);
MPI s, m = mpi_alloc(0);
int ret = 0;
int sign;
if (!m)
return -ENOMEM;
if (unlikely(!pkey->n || !pkey->e)) {
ret = -EINVAL;
goto err_free_m;
}
if (req->dst_len < mpi_get_size(pkey->n)) {
req->dst_len = mpi_get_size(pkey->n);
ret = -EOVERFLOW;
goto err_free_m;
}
s = mpi_read_raw_data(req->src, req->src_len);
if (!s) {
ret = -ENOMEM;
goto err_free_m;
}
ret = _rsa_verify(pkey, m, s);
if (ret)
goto err_free_s;
ret = mpi_read_buffer(m, req->dst, req->dst_len, &req->dst_len, &sign);
if (ret)
goto err_free_s;
if (sign < 0) {
ret = -EBADMSG;
goto err_free_s;
}
err_free_s:
mpi_free(s);
err_free_m:
mpi_free(m);
return ret;
}
static int rsa_setkey(struct crypto_akcipher *tfm, const void *key,
unsigned int keylen)
{
struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
return rsa_parse_key(pkey, key, keylen);
}
static void rsa_exit_tfm(struct crypto_akcipher *tfm)
{
struct rsa_key *pkey = akcipher_tfm_ctx(tfm);
rsa_free_key(pkey);
}
static struct akcipher_alg rsa = {
.encrypt = rsa_enc,
.decrypt = rsa_dec,
.sign = rsa_sign,
.verify = rsa_verify,
.setkey = rsa_setkey,
.exit = rsa_exit_tfm,
.base = {
.cra_name = "rsa",
.cra_driver_name = "rsa-generic",
.cra_priority = 100,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct rsa_key),
},
};
static int rsa_init(void)
{
return crypto_register_akcipher(&rsa);
}
static void rsa_exit(void)
{
crypto_unregister_akcipher(&rsa);
}
module_init(rsa_init);
module_exit(rsa_exit);
MODULE_ALIAS_CRYPTO("rsa");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RSA generic algorithm");
/*
* RSA key extract helper
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/fips.h>
#include <crypto/internal/rsa.h>
#include "rsakey-asn1.h"
int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
key->n = mpi_read_raw_data(value, vlen);
if (!key->n)
return -ENOMEM;
/* In FIPS mode only allow key size 2K & 3K */
if (fips_enabled && (mpi_get_size(key->n) != 256 ||
mpi_get_size(key->n) != 384)) {
pr_err("RSA: key size not allowed in FIPS mode\n");
mpi_free(key->n);
key->n = NULL;
return -EINVAL;
}
return 0;
}
int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
key->e = mpi_read_raw_data(value, vlen);
if (!key->e)
return -ENOMEM;
return 0;
}
int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
key->d = mpi_read_raw_data(value, vlen);
if (!key->d)
return -ENOMEM;
/* In FIPS mode only allow key size 2K & 3K */
if (fips_enabled && (mpi_get_size(key->d) != 256 ||
mpi_get_size(key->d) != 384)) {
pr_err("RSA: key size not allowed in FIPS mode\n");
mpi_free(key->d);
key->d = NULL;
return -EINVAL;
}
return 0;
}
static void free_mpis(struct rsa_key *key)
{
mpi_free(key->n);
mpi_free(key->e);
mpi_free(key->d);
key->n = NULL;
key->e = NULL;
key->d = NULL;
}
/**
* rsa_free_key() - frees rsa key allocated by rsa_parse_key()
*
* @rsa_key: struct rsa_key key representation
*/
void rsa_free_key(struct rsa_key *key)
{
free_mpis(key);
}
EXPORT_SYMBOL_GPL(rsa_free_key);
/**
* rsa_parse_key() - extracts an rsa key from BER encoded buffer
* and stores it in the provided struct rsa_key
*
* @rsa_key: struct rsa_key key representation
* @key: key in BER format
* @key_len: length of key
*
* Return: 0 on success or error code in case of error
*/
int rsa_parse_key(struct rsa_key *rsa_key, const void *key,
unsigned int key_len)
{
int ret;
free_mpis(rsa_key);
ret = asn1_ber_decoder(&rsakey_decoder, rsa_key, key, key_len);
if (ret < 0)
goto error;
return 0;
error:
free_mpis(rsa_key);
return ret;
}
EXPORT_SYMBOL_GPL(rsa_parse_key);
RsaKey ::= SEQUENCE {
n INTEGER ({ rsa_get_n }),
e INTEGER ({ rsa_get_e }),
d INTEGER ({ rsa_get_d })
}
/*
* RSA internal helpers
*
* 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 _RSA_HELPER_
#define _RSA_HELPER_
#include <linux/mpi.h>
struct rsa_key {
MPI n;
MPI e;
MPI d;
};
int rsa_parse_key(struct rsa_key *rsa_key, const void *key,
unsigned int key_len);
void rsa_free_key(struct rsa_key *rsa_key);
#endif
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