1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * geniv: Shared IV generator code |
4 | * |
5 | * This file provides common code to IV generators such as seqiv. |
6 | * |
7 | * Copyright (c) 2007-2019 Herbert Xu <herbert@gondor.apana.org.au> |
8 | */ |
9 | |
10 | #include <crypto/internal/geniv.h> |
11 | #include <crypto/internal/rng.h> |
12 | #include <crypto/null.h> |
13 | #include <linux/err.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> |
16 | #include <linux/rtnetlink.h> |
17 | #include <linux/slab.h> |
18 | |
19 | static int aead_geniv_setkey(struct crypto_aead *tfm, |
20 | const u8 *key, unsigned int keylen) |
21 | { |
22 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); |
23 | |
24 | return crypto_aead_setkey(tfm: ctx->child, key, keylen); |
25 | } |
26 | |
27 | static int aead_geniv_setauthsize(struct crypto_aead *tfm, |
28 | unsigned int authsize) |
29 | { |
30 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); |
31 | |
32 | return crypto_aead_setauthsize(tfm: ctx->child, authsize); |
33 | } |
34 | |
35 | static void aead_geniv_free(struct aead_instance *inst) |
36 | { |
37 | crypto_drop_aead(spawn: aead_instance_ctx(inst)); |
38 | kfree(objp: inst); |
39 | } |
40 | |
41 | struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl, |
42 | struct rtattr **tb) |
43 | { |
44 | struct crypto_aead_spawn *spawn; |
45 | struct aead_instance *inst; |
46 | struct aead_alg *alg; |
47 | unsigned int ivsize; |
48 | unsigned int maxauthsize; |
49 | u32 mask; |
50 | int err; |
51 | |
52 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, mask_ret: &mask); |
53 | if (err) |
54 | return ERR_PTR(error: err); |
55 | |
56 | inst = kzalloc(size: sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); |
57 | if (!inst) |
58 | return ERR_PTR(error: -ENOMEM); |
59 | |
60 | spawn = aead_instance_ctx(inst); |
61 | |
62 | err = crypto_grab_aead(spawn, inst: aead_crypto_instance(inst), |
63 | name: crypto_attr_alg_name(rta: tb[1]), type: 0, mask); |
64 | if (err) |
65 | goto err_free_inst; |
66 | |
67 | alg = crypto_spawn_aead_alg(spawn); |
68 | |
69 | ivsize = crypto_aead_alg_ivsize(alg); |
70 | maxauthsize = crypto_aead_alg_maxauthsize(alg); |
71 | |
72 | err = -EINVAL; |
73 | if (ivsize < sizeof(u64)) |
74 | goto err_free_inst; |
75 | |
76 | err = -ENAMETOOLONG; |
77 | if (snprintf(buf: inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
78 | fmt: "%s(%s)" , tmpl->name, alg->base.cra_name) >= |
79 | CRYPTO_MAX_ALG_NAME) |
80 | goto err_free_inst; |
81 | if (snprintf(buf: inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
82 | fmt: "%s(%s)" , tmpl->name, alg->base.cra_driver_name) >= |
83 | CRYPTO_MAX_ALG_NAME) |
84 | goto err_free_inst; |
85 | |
86 | inst->alg.base.cra_priority = alg->base.cra_priority; |
87 | inst->alg.base.cra_blocksize = alg->base.cra_blocksize; |
88 | inst->alg.base.cra_alignmask = alg->base.cra_alignmask; |
89 | inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); |
90 | |
91 | inst->alg.setkey = aead_geniv_setkey; |
92 | inst->alg.setauthsize = aead_geniv_setauthsize; |
93 | |
94 | inst->alg.ivsize = ivsize; |
95 | inst->alg.maxauthsize = maxauthsize; |
96 | |
97 | inst->free = aead_geniv_free; |
98 | |
99 | out: |
100 | return inst; |
101 | |
102 | err_free_inst: |
103 | aead_geniv_free(inst); |
104 | inst = ERR_PTR(error: err); |
105 | goto out; |
106 | } |
107 | EXPORT_SYMBOL_GPL(aead_geniv_alloc); |
108 | |
109 | int aead_init_geniv(struct crypto_aead *aead) |
110 | { |
111 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm: aead); |
112 | struct aead_instance *inst = aead_alg_instance(aead); |
113 | struct crypto_aead *child; |
114 | int err; |
115 | |
116 | spin_lock_init(&ctx->lock); |
117 | |
118 | err = crypto_get_default_rng(); |
119 | if (err) |
120 | goto out; |
121 | |
122 | err = crypto_rng_get_bytes(tfm: crypto_default_rng, rdata: ctx->salt, |
123 | dlen: crypto_aead_ivsize(tfm: aead)); |
124 | crypto_put_default_rng(); |
125 | if (err) |
126 | goto out; |
127 | |
128 | ctx->sknull = crypto_get_default_null_skcipher(); |
129 | err = PTR_ERR(ptr: ctx->sknull); |
130 | if (IS_ERR(ptr: ctx->sknull)) |
131 | goto out; |
132 | |
133 | child = crypto_spawn_aead(spawn: aead_instance_ctx(inst)); |
134 | err = PTR_ERR(ptr: child); |
135 | if (IS_ERR(ptr: child)) |
136 | goto drop_null; |
137 | |
138 | ctx->child = child; |
139 | crypto_aead_set_reqsize(aead, reqsize: crypto_aead_reqsize(tfm: child) + |
140 | sizeof(struct aead_request)); |
141 | |
142 | err = 0; |
143 | |
144 | out: |
145 | return err; |
146 | |
147 | drop_null: |
148 | crypto_put_default_null_skcipher(); |
149 | goto out; |
150 | } |
151 | EXPORT_SYMBOL_GPL(aead_init_geniv); |
152 | |
153 | void aead_exit_geniv(struct crypto_aead *tfm) |
154 | { |
155 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm); |
156 | |
157 | crypto_free_aead(tfm: ctx->child); |
158 | crypto_put_default_null_skcipher(); |
159 | } |
160 | EXPORT_SYMBOL_GPL(aead_exit_geniv); |
161 | |
162 | MODULE_LICENSE("GPL" ); |
163 | MODULE_DESCRIPTION("Shared IV generator code" ); |
164 | |