mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
1ce1bacc48
FIPS disallows RSA with keys < 2048 bits. Thus, the kernel should consider the enforcement of this limit. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
290 lines
5.4 KiB
C
290 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* RSA asymmetric public-key algorithm [RFC3447]
|
|
*
|
|
* Copyright (c) 2015, Intel Corporation
|
|
* Authors: Tadeusz Struk <tadeusz.struk@intel.com>
|
|
*/
|
|
|
|
#include <linux/fips.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mpi.h>
|
|
#include <crypto/internal/rsa.h>
|
|
#include <crypto/internal/akcipher.h>
|
|
#include <crypto/akcipher.h>
|
|
#include <crypto/algapi.h>
|
|
|
|
struct rsa_mpi_key {
|
|
MPI n;
|
|
MPI e;
|
|
MPI d;
|
|
};
|
|
|
|
/*
|
|
* RSAEP function [RFC3447 sec 5.1.1]
|
|
* c = m^e mod n;
|
|
*/
|
|
static int _rsa_enc(const struct rsa_mpi_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_mpi_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);
|
|
}
|
|
|
|
static inline struct rsa_mpi_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_mpi_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;
|
|
}
|
|
|
|
ret = -ENOMEM;
|
|
m = mpi_read_raw_from_sgl(req->src, req->src_len);
|
|
if (!m)
|
|
goto err_free_c;
|
|
|
|
ret = _rsa_enc(pkey, c, m);
|
|
if (ret)
|
|
goto err_free_m;
|
|
|
|
ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
|
|
if (ret)
|
|
goto err_free_m;
|
|
|
|
if (sign < 0)
|
|
ret = -EBADMSG;
|
|
|
|
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_mpi_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;
|
|
}
|
|
|
|
ret = -ENOMEM;
|
|
c = mpi_read_raw_from_sgl(req->src, req->src_len);
|
|
if (!c)
|
|
goto err_free_m;
|
|
|
|
ret = _rsa_dec(pkey, m, c);
|
|
if (ret)
|
|
goto err_free_c;
|
|
|
|
ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
|
|
if (ret)
|
|
goto err_free_c;
|
|
|
|
if (sign < 0)
|
|
ret = -EBADMSG;
|
|
err_free_c:
|
|
mpi_free(c);
|
|
err_free_m:
|
|
mpi_free(m);
|
|
return ret;
|
|
}
|
|
|
|
static void rsa_free_mpi_key(struct rsa_mpi_key *key)
|
|
{
|
|
mpi_free(key->d);
|
|
mpi_free(key->e);
|
|
mpi_free(key->n);
|
|
key->d = NULL;
|
|
key->e = NULL;
|
|
key->n = NULL;
|
|
}
|
|
|
|
static int rsa_check_key_length(unsigned int len)
|
|
{
|
|
switch (len) {
|
|
case 512:
|
|
case 1024:
|
|
case 1536:
|
|
if (fips_enabled)
|
|
return -EINVAL;
|
|
fallthrough;
|
|
case 2048:
|
|
case 3072:
|
|
case 4096:
|
|
return 0;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
|
|
unsigned int keylen)
|
|
{
|
|
struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
|
|
struct rsa_key raw_key = {0};
|
|
int ret;
|
|
|
|
/* Free the old MPI key if any */
|
|
rsa_free_mpi_key(mpi_key);
|
|
|
|
ret = rsa_parse_pub_key(&raw_key, key, keylen);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
|
|
if (!mpi_key->e)
|
|
goto err;
|
|
|
|
mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
|
|
if (!mpi_key->n)
|
|
goto err;
|
|
|
|
if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
|
|
rsa_free_mpi_key(mpi_key);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
rsa_free_mpi_key(mpi_key);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
|
|
unsigned int keylen)
|
|
{
|
|
struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
|
|
struct rsa_key raw_key = {0};
|
|
int ret;
|
|
|
|
/* Free the old MPI key if any */
|
|
rsa_free_mpi_key(mpi_key);
|
|
|
|
ret = rsa_parse_priv_key(&raw_key, key, keylen);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
|
|
if (!mpi_key->d)
|
|
goto err;
|
|
|
|
mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
|
|
if (!mpi_key->e)
|
|
goto err;
|
|
|
|
mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
|
|
if (!mpi_key->n)
|
|
goto err;
|
|
|
|
if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
|
|
rsa_free_mpi_key(mpi_key);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
rsa_free_mpi_key(mpi_key);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
|
|
{
|
|
struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
|
|
|
|
return mpi_get_size(pkey->n);
|
|
}
|
|
|
|
static void rsa_exit_tfm(struct crypto_akcipher *tfm)
|
|
{
|
|
struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
|
|
|
|
rsa_free_mpi_key(pkey);
|
|
}
|
|
|
|
static struct akcipher_alg rsa = {
|
|
.encrypt = rsa_enc,
|
|
.decrypt = rsa_dec,
|
|
.set_priv_key = rsa_set_priv_key,
|
|
.set_pub_key = rsa_set_pub_key,
|
|
.max_size = rsa_max_size,
|
|
.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_mpi_key),
|
|
},
|
|
};
|
|
|
|
static int rsa_init(void)
|
|
{
|
|
int err;
|
|
|
|
err = crypto_register_akcipher(&rsa);
|
|
if (err)
|
|
return err;
|
|
|
|
err = crypto_register_template(&rsa_pkcs1pad_tmpl);
|
|
if (err) {
|
|
crypto_unregister_akcipher(&rsa);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void rsa_exit(void)
|
|
{
|
|
crypto_unregister_template(&rsa_pkcs1pad_tmpl);
|
|
crypto_unregister_akcipher(&rsa);
|
|
}
|
|
|
|
subsys_initcall(rsa_init);
|
|
module_exit(rsa_exit);
|
|
MODULE_ALIAS_CRYPTO("rsa");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("RSA generic algorithm");
|