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

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

crypto/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -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

crypto/Makefile

+8 −0
Original line number Diff line number Diff line
@@ -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

crypto/rsa.c

0 → 100644
+315 −0
Original line number Diff line number Diff line 
/* 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");

crypto/rsa_helper.c

0 → 100644
+121 −0
Original line number Diff line number Diff line 
/*

 * 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);

crypto/rsakey.asn1

0 → 100644
+5 −0
Original line number Diff line number Diff line 
RsaKey ::= SEQUENCE {

	n INTEGER ({ rsa_get_n }),

	e INTEGER ({ rsa_get_e }),

	d INTEGER ({ rsa_get_d })

}