2026-01-29 22:25:33 +08:00

264 lines
6.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RSA key extract helper
*
* Copyright (c) 2015, Intel Corporation
* Authors: Tadeusz Struk <tadeusz.struk@intel.com>
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/fips.h>
#ifdef CONFIG_PGP_LIBRARY
#include <linux/mpi.h>
#endif
#include <crypto/internal/rsa.h>
#include "rsapubkey.asn1.h"
#include "rsaprivkey.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;
const u8 *ptr = value;
size_t n_sz = vlen;
/* invalid key provided */
if (!value || !vlen)
return -EINVAL;
if (fips_enabled) {
while (n_sz && !*ptr) {
ptr++;
n_sz--;
}
/* In FIPS mode only allow key size 2K and higher */
if (n_sz < 256) {
pr_err("RSA: key size not allowed in FIPS mode\n");
return -EINVAL;
}
}
key->n = value;
key->n_sz = vlen;
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;
/* invalid key provided */
if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
return -EINVAL;
key->e = value;
key->e_sz = vlen;
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;
/* invalid key provided */
if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
return -EINVAL;
key->d = value;
key->d_sz = vlen;
return 0;
}
int rsa_get_p(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
/* invalid key provided */
if (!value || !vlen || vlen > key->n_sz)
return -EINVAL;
key->p = value;
key->p_sz = vlen;
return 0;
}
int rsa_get_q(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
/* invalid key provided */
if (!value || !vlen || vlen > key->n_sz)
return -EINVAL;
key->q = value;
key->q_sz = vlen;
return 0;
}
int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
/* invalid key provided */
if (!value || !vlen || vlen > key->n_sz)
return -EINVAL;
key->dp = value;
key->dp_sz = vlen;
return 0;
}
int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
/* invalid key provided */
if (!value || !vlen || vlen > key->n_sz)
return -EINVAL;
key->dq = value;
key->dq_sz = vlen;
return 0;
}
int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
struct rsa_key *key = context;
/* invalid key provided */
if (!value || !vlen || vlen > key->n_sz)
return -EINVAL;
key->qinv = value;
key->qinv_sz = vlen;
return 0;
}
#ifdef CONFIG_PGP_LIBRARY
typedef int (*rsa_get_func)(void *, size_t, unsigned char,
const void *, size_t);
static int rsa_parse_key_raw(struct rsa_key *rsa_key,
const void *key, unsigned int key_len,
rsa_get_func *func, int n_func)
{
unsigned int nbytes, len = key_len;
const void *key_ptr = key;
int ret, i;
for (i = 0; i < n_func; i++) {
ret = mpi_key_length(key_ptr, len, NULL, &nbytes);
if (ret < 0)
return ret;
ret = func[i](rsa_key, 0, 0, key_ptr + 2, nbytes);
if (ret < 0)
return ret;
key_ptr += nbytes + 2;
}
return (key_ptr == key + key_len) ? 0 : -EINVAL;
}
#endif
/**
* rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the
* provided struct rsa_key, pointers to the raw key as is,
* so that the caller can copy it or MPI parse it, etc.
*
* @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_pub_key(struct rsa_key *rsa_key, const void *key,
unsigned int key_len)
{
return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len);
}
EXPORT_SYMBOL_GPL(rsa_parse_pub_key);
#ifdef CONFIG_PGP_LIBRARY
/**
* rsa_parse_pub_key_raw() - parse the RAW key and store in the provided struct
* rsa_key, pointers to the raw key as is, so that
* the caller can copy it or MPI parse it, etc.
*
* @rsa_key: struct rsa_key key representation
* @key: key in RAW format
* @key_len: length of key
*
* Return: 0 on success or error code in case of error
*/
int rsa_parse_pub_key_raw(struct rsa_key *rsa_key, const void *key,
unsigned int key_len)
{
rsa_get_func pub_func[] = {rsa_get_n, rsa_get_e};
return rsa_parse_key_raw(rsa_key, key, key_len,
pub_func, ARRAY_SIZE(pub_func));
}
EXPORT_SYMBOL_GPL(rsa_parse_pub_key_raw);
#endif
/**
* rsa_parse_priv_key() - decodes the BER encoded buffer and stores in the
* provided struct rsa_key, pointers to the raw key
* as is, so that the caller can copy it or MPI parse it,
* etc.
*
* @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_priv_key(struct rsa_key *rsa_key, const void *key,
unsigned int key_len)
{
return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len);
}
EXPORT_SYMBOL_GPL(rsa_parse_priv_key);
#ifdef CONFIG_PGP_LIBRARY
/**
* rsa_parse_priv_key_raw() - parse the RAW key and store in the provided struct
* rsa_key, pointers to the raw key as is, so that
* the caller can copy it or MPI parse it, etc.
*
* @rsa_key: struct rsa_key key representation
* @key: key in RAW format
* @key_len: length of key
*
* Return: 0 on success or error code in case of error
*/
int rsa_parse_priv_key_raw(struct rsa_key *rsa_key, const void *key,
unsigned int key_len)
{
rsa_get_func priv_func[] = {rsa_get_n, rsa_get_e, rsa_get_d};
return rsa_parse_key_raw(rsa_key, key, key_len,
priv_func, ARRAY_SIZE(priv_func));
}
EXPORT_SYMBOL_GPL(rsa_parse_priv_key_raw);
#endif