Loading...
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * DES & Triple DES EDE key verification helpers
4 */
5
6#ifndef __CRYPTO_INTERNAL_DES_H
7#define __CRYPTO_INTERNAL_DES_H
8
9#include <linux/crypto.h>
10#include <linux/fips.h>
11#include <crypto/des.h>
12#include <crypto/aead.h>
13#include <crypto/skcipher.h>
14
15/**
16 * crypto_des_verify_key - Check whether a DES key is weak
17 * @tfm: the crypto algo
18 * @key: the key buffer
19 *
20 * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak
21 * keys. Otherwise, 0 is returned.
22 *
23 * It is the job of the caller to ensure that the size of the key equals
24 * DES_KEY_SIZE.
25 */
26static inline int crypto_des_verify_key(struct crypto_tfm *tfm, const u8 *key)
27{
28 struct des_ctx tmp;
29 int err;
30
31 err = des_expand_key(&tmp, key, DES_KEY_SIZE);
32 if (err == -ENOKEY) {
33 if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)
34 err = -EINVAL;
35 else
36 err = 0;
37 }
38
39 if (err)
40 crypto_tfm_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
41
42 memzero_explicit(&tmp, sizeof(tmp));
43 return err;
44}
45
46/*
47 * RFC2451:
48 *
49 * For DES-EDE3, there is no known need to reject weak or
50 * complementation keys. Any weakness is obviated by the use of
51 * multiple keys.
52 *
53 * However, if the first two or last two independent 64-bit keys are
54 * equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the
55 * same as DES. Implementers MUST reject keys that exhibit this
56 * property.
57 *
58 */
59static inline int des3_ede_verify_key(const u8 *key, unsigned int key_len,
60 bool check_weak)
61{
62 int ret = fips_enabled ? -EINVAL : -ENOKEY;
63 u32 K[6];
64
65 memcpy(K, key, DES3_EDE_KEY_SIZE);
66
67 if ((!((K[0] ^ K[2]) | (K[1] ^ K[3])) ||
68 !((K[2] ^ K[4]) | (K[3] ^ K[5]))) &&
69 (fips_enabled || check_weak))
70 goto bad;
71
72 if ((!((K[0] ^ K[4]) | (K[1] ^ K[5]))) && fips_enabled)
73 goto bad;
74
75 ret = 0;
76bad:
77 memzero_explicit(K, DES3_EDE_KEY_SIZE);
78
79 return ret;
80}
81
82/**
83 * crypto_des3_ede_verify_key - Check whether a DES3-EDE key is weak
84 * @tfm: the crypto algo
85 * @key: the key buffer
86 *
87 * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak
88 * keys or when running in FIPS mode. Otherwise, 0 is returned. Note that some
89 * keys are rejected in FIPS mode even if weak keys are permitted by the TFM
90 * flags.
91 *
92 * It is the job of the caller to ensure that the size of the key equals
93 * DES3_EDE_KEY_SIZE.
94 */
95static inline int crypto_des3_ede_verify_key(struct crypto_tfm *tfm,
96 const u8 *key)
97{
98 int err;
99
100 err = des3_ede_verify_key(key, DES3_EDE_KEY_SIZE,
101 crypto_tfm_get_flags(tfm) &
102 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
103 if (err)
104 crypto_tfm_set_flags(tfm, CRYPTO_TFM_RES_WEAK_KEY);
105 return err;
106}
107
108static inline int verify_skcipher_des_key(struct crypto_skcipher *tfm,
109 const u8 *key)
110{
111 return crypto_des_verify_key(crypto_skcipher_tfm(tfm), key);
112}
113
114static inline int verify_skcipher_des3_key(struct crypto_skcipher *tfm,
115 const u8 *key)
116{
117 return crypto_des3_ede_verify_key(crypto_skcipher_tfm(tfm), key);
118}
119
120static inline int verify_ablkcipher_des_key(struct crypto_ablkcipher *tfm,
121 const u8 *key)
122{
123 return crypto_des_verify_key(crypto_ablkcipher_tfm(tfm), key);
124}
125
126static inline int verify_ablkcipher_des3_key(struct crypto_ablkcipher *tfm,
127 const u8 *key)
128{
129 return crypto_des3_ede_verify_key(crypto_ablkcipher_tfm(tfm), key);
130}
131
132static inline int verify_aead_des_key(struct crypto_aead *tfm, const u8 *key,
133 int keylen)
134{
135 if (keylen != DES_KEY_SIZE) {
136 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
137 return -EINVAL;
138 }
139 return crypto_des_verify_key(crypto_aead_tfm(tfm), key);
140}
141
142static inline int verify_aead_des3_key(struct crypto_aead *tfm, const u8 *key,
143 int keylen)
144{
145 if (keylen != DES3_EDE_KEY_SIZE) {
146 crypto_aead_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
147 return -EINVAL;
148 }
149 return crypto_des3_ede_verify_key(crypto_aead_tfm(tfm), key);
150}
151
152#endif /* __CRYPTO_INTERNAL_DES_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * DES & Triple DES EDE key verification helpers
4 */
5
6#ifndef __CRYPTO_INTERNAL_DES_H
7#define __CRYPTO_INTERNAL_DES_H
8
9#include <linux/crypto.h>
10#include <linux/fips.h>
11#include <crypto/des.h>
12#include <crypto/aead.h>
13#include <crypto/skcipher.h>
14
15/**
16 * crypto_des_verify_key - Check whether a DES key is weak
17 * @tfm: the crypto algo
18 * @key: the key buffer
19 *
20 * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak
21 * keys. Otherwise, 0 is returned.
22 *
23 * It is the job of the caller to ensure that the size of the key equals
24 * DES_KEY_SIZE.
25 */
26static inline int crypto_des_verify_key(struct crypto_tfm *tfm, const u8 *key)
27{
28 struct des_ctx tmp;
29 int err;
30
31 err = des_expand_key(&tmp, key, DES_KEY_SIZE);
32 if (err == -ENOKEY) {
33 if (crypto_tfm_get_flags(tfm) & CRYPTO_TFM_REQ_FORBID_WEAK_KEYS)
34 err = -EINVAL;
35 else
36 err = 0;
37 }
38 memzero_explicit(&tmp, sizeof(tmp));
39 return err;
40}
41
42/*
43 * RFC2451:
44 *
45 * For DES-EDE3, there is no known need to reject weak or
46 * complementation keys. Any weakness is obviated by the use of
47 * multiple keys.
48 *
49 * However, if the first two or last two independent 64-bit keys are
50 * equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the
51 * same as DES. Implementers MUST reject keys that exhibit this
52 * property.
53 *
54 */
55static inline int des3_ede_verify_key(const u8 *key, unsigned int key_len,
56 bool check_weak)
57{
58 int ret = fips_enabled ? -EINVAL : -ENOKEY;
59 u32 K[6];
60
61 memcpy(K, key, DES3_EDE_KEY_SIZE);
62
63 if ((!((K[0] ^ K[2]) | (K[1] ^ K[3])) ||
64 !((K[2] ^ K[4]) | (K[3] ^ K[5]))) &&
65 (fips_enabled || check_weak))
66 goto bad;
67
68 if ((!((K[0] ^ K[4]) | (K[1] ^ K[5]))) && fips_enabled)
69 goto bad;
70
71 ret = 0;
72bad:
73 memzero_explicit(K, DES3_EDE_KEY_SIZE);
74
75 return ret;
76}
77
78/**
79 * crypto_des3_ede_verify_key - Check whether a DES3-EDE key is weak
80 * @tfm: the crypto algo
81 * @key: the key buffer
82 *
83 * Returns -EINVAL if the key is weak and the crypto TFM does not permit weak
84 * keys or when running in FIPS mode. Otherwise, 0 is returned. Note that some
85 * keys are rejected in FIPS mode even if weak keys are permitted by the TFM
86 * flags.
87 *
88 * It is the job of the caller to ensure that the size of the key equals
89 * DES3_EDE_KEY_SIZE.
90 */
91static inline int crypto_des3_ede_verify_key(struct crypto_tfm *tfm,
92 const u8 *key)
93{
94 return des3_ede_verify_key(key, DES3_EDE_KEY_SIZE,
95 crypto_tfm_get_flags(tfm) &
96 CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
97}
98
99static inline int verify_skcipher_des_key(struct crypto_skcipher *tfm,
100 const u8 *key)
101{
102 return crypto_des_verify_key(crypto_skcipher_tfm(tfm), key);
103}
104
105static inline int verify_skcipher_des3_key(struct crypto_skcipher *tfm,
106 const u8 *key)
107{
108 return crypto_des3_ede_verify_key(crypto_skcipher_tfm(tfm), key);
109}
110
111static inline int verify_aead_des_key(struct crypto_aead *tfm, const u8 *key,
112 int keylen)
113{
114 if (keylen != DES_KEY_SIZE)
115 return -EINVAL;
116 return crypto_des_verify_key(crypto_aead_tfm(tfm), key);
117}
118
119static inline int verify_aead_des3_key(struct crypto_aead *tfm, const u8 *key,
120 int keylen)
121{
122 if (keylen != DES3_EDE_KEY_SIZE)
123 return -EINVAL;
124 return crypto_des3_ede_verify_key(crypto_aead_tfm(tfm), key);
125}
126
127#endif /* __CRYPTO_INTERNAL_DES_H */