1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RSA key extract helper
4 *
5 * Copyright (c) 2015, Intel Corporation
6 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
7 */
8#include <linux/kernel.h>
9#include <linux/export.h>
10#include <linux/err.h>
11#include <linux/fips.h>
12#include <crypto/internal/rsa.h>
13#include "rsapubkey.asn1.h"
14#include "rsaprivkey.asn1.h"
15
16int rsa_get_n(void *context, size_t hdrlen, unsigned char tag,
17	      const void *value, size_t vlen)
18{
19	struct rsa_key *key = context;
20	const u8 *ptr = value;
21	size_t n_sz = vlen;
22
23	/* invalid key provided */
24	if (!value || !vlen)
25		return -EINVAL;
26
27	if (fips_enabled) {
28		while (n_sz && !*ptr) {
29			ptr++;
30			n_sz--;
31		}
32
33		/* In FIPS mode only allow key size 2K and higher */
34		if (n_sz < 256) {
35			pr_err("RSA: key size not allowed in FIPS mode\n");
36			return -EINVAL;
37		}
38	}
39
40	key->n = value;
41	key->n_sz = vlen;
42
43	return 0;
44}
45
46int rsa_get_e(void *context, size_t hdrlen, unsigned char tag,
47	      const void *value, size_t vlen)
48{
49	struct rsa_key *key = context;
50
51	/* invalid key provided */
52	if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
53		return -EINVAL;
54
55	key->e = value;
56	key->e_sz = vlen;
57
58	return 0;
59}
60
61int rsa_get_d(void *context, size_t hdrlen, unsigned char tag,
62	      const void *value, size_t vlen)
63{
64	struct rsa_key *key = context;
65
66	/* invalid key provided */
67	if (!value || !key->n_sz || !vlen || vlen > key->n_sz)
68		return -EINVAL;
69
70	key->d = value;
71	key->d_sz = vlen;
72
73	return 0;
74}
75
76int rsa_get_p(void *context, size_t hdrlen, unsigned char tag,
77	      const void *value, size_t vlen)
78{
79	struct rsa_key *key = context;
80
81	/* invalid key provided */
82	if (!value || !vlen || vlen > key->n_sz)
83		return -EINVAL;
84
85	key->p = value;
86	key->p_sz = vlen;
87
88	return 0;
89}
90
91int rsa_get_q(void *context, size_t hdrlen, unsigned char tag,
92	      const void *value, size_t vlen)
93{
94	struct rsa_key *key = context;
95
96	/* invalid key provided */
97	if (!value || !vlen || vlen > key->n_sz)
98		return -EINVAL;
99
100	key->q = value;
101	key->q_sz = vlen;
102
103	return 0;
104}
105
106int rsa_get_dp(void *context, size_t hdrlen, unsigned char tag,
107	       const void *value, size_t vlen)
108{
109	struct rsa_key *key = context;
110
111	/* invalid key provided */
112	if (!value || !vlen || vlen > key->n_sz)
113		return -EINVAL;
114
115	key->dp = value;
116	key->dp_sz = vlen;
117
118	return 0;
119}
120
121int rsa_get_dq(void *context, size_t hdrlen, unsigned char tag,
122	       const void *value, size_t vlen)
123{
124	struct rsa_key *key = context;
125
126	/* invalid key provided */
127	if (!value || !vlen || vlen > key->n_sz)
128		return -EINVAL;
129
130	key->dq = value;
131	key->dq_sz = vlen;
132
133	return 0;
134}
135
136int rsa_get_qinv(void *context, size_t hdrlen, unsigned char tag,
137		 const void *value, size_t vlen)
138{
139	struct rsa_key *key = context;
140
141	/* invalid key provided */
142	if (!value || !vlen || vlen > key->n_sz)
143		return -EINVAL;
144
145	key->qinv = value;
146	key->qinv_sz = vlen;
147
148	return 0;
149}
150
151/**
152 * rsa_parse_pub_key() - decodes the BER encoded buffer and stores in the
153 *                       provided struct rsa_key, pointers to the raw key as is,
154 *                       so that the caller can copy it or MPI parse it, etc.
155 *
156 * @rsa_key:	struct rsa_key key representation
157 * @key:	key in BER format
158 * @key_len:	length of key
159 *
160 * Return:	0 on success or error code in case of error
161 */
162int rsa_parse_pub_key(struct rsa_key *rsa_key, const void *key,
163		      unsigned int key_len)
164{
165	return asn1_ber_decoder(&rsapubkey_decoder, rsa_key, key, key_len);
166}
167EXPORT_SYMBOL_GPL(rsa_parse_pub_key);
168
169/**
170 * rsa_parse_priv_key() - decodes the BER encoded buffer and stores in the
171 *                        provided struct rsa_key, pointers to the raw key
172 *                        as is, so that the caller can copy it or MPI parse it,
173 *                        etc.
174 *
175 * @rsa_key:	struct rsa_key key representation
176 * @key:	key in BER format
177 * @key_len:	length of key
178 *
179 * Return:	0 on success or error code in case of error
180 */
181int rsa_parse_priv_key(struct rsa_key *rsa_key, const void *key,
182		       unsigned int key_len)
183{
184	return asn1_ber_decoder(&rsaprivkey_decoder, rsa_key, key, key_len);
185}
186EXPORT_SYMBOL_GPL(rsa_parse_priv_key);
187