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 <linux/err.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/slab.h>
17
aead_geniv_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)18 static int aead_geniv_setkey(struct crypto_aead *tfm,
19 const u8 *key, unsigned int keylen)
20 {
21 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
22
23 return crypto_aead_setkey(ctx->child, key, keylen);
24 }
25
aead_geniv_setauthsize(struct crypto_aead * tfm,unsigned int authsize)26 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
27 unsigned int authsize)
28 {
29 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
30
31 return crypto_aead_setauthsize(ctx->child, authsize);
32 }
33
aead_geniv_free(struct aead_instance * inst)34 static void aead_geniv_free(struct aead_instance *inst)
35 {
36 crypto_drop_aead(aead_instance_ctx(inst));
37 kfree(inst);
38 }
39
aead_geniv_alloc(struct crypto_template * tmpl,struct rtattr ** tb)40 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
41 struct rtattr **tb)
42 {
43 struct crypto_aead_spawn *spawn;
44 struct aead_instance *inst;
45 struct aead_alg *alg;
46 unsigned int ivsize;
47 unsigned int maxauthsize;
48 u32 mask;
49 int err;
50
51 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
52 if (err)
53 return ERR_PTR(err);
54
55 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
56 if (!inst)
57 return ERR_PTR(-ENOMEM);
58
59 spawn = aead_instance_ctx(inst);
60
61 err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
62 crypto_attr_alg_name(tb[1]), 0, mask);
63 if (err)
64 goto err_free_inst;
65
66 alg = crypto_spawn_aead_alg(spawn);
67
68 ivsize = crypto_aead_alg_ivsize(alg);
69 maxauthsize = crypto_aead_alg_maxauthsize(alg);
70
71 err = -EINVAL;
72 if (ivsize < sizeof(u64))
73 goto err_free_inst;
74
75 err = -ENAMETOOLONG;
76 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
77 "%s(%s)", tmpl->name, alg->base.cra_name) >=
78 CRYPTO_MAX_ALG_NAME)
79 goto err_free_inst;
80 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
81 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
82 CRYPTO_MAX_ALG_NAME)
83 goto err_free_inst;
84
85 inst->alg.base.cra_priority = alg->base.cra_priority;
86 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
87 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
88 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
89
90 inst->alg.setkey = aead_geniv_setkey;
91 inst->alg.setauthsize = aead_geniv_setauthsize;
92
93 inst->alg.ivsize = ivsize;
94 inst->alg.maxauthsize = maxauthsize;
95
96 inst->free = aead_geniv_free;
97
98 out:
99 return inst;
100
101 err_free_inst:
102 aead_geniv_free(inst);
103 inst = ERR_PTR(err);
104 goto out;
105 }
106 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
107
aead_init_geniv(struct crypto_aead * aead)108 int aead_init_geniv(struct crypto_aead *aead)
109 {
110 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
111 struct aead_instance *inst = aead_alg_instance(aead);
112 struct crypto_aead *child;
113 int err;
114
115 spin_lock_init(&ctx->lock);
116
117 err = crypto_get_default_rng();
118 if (err)
119 goto out;
120
121 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
122 crypto_aead_ivsize(aead));
123 crypto_put_default_rng();
124 if (err)
125 goto out;
126
127 child = crypto_spawn_aead(aead_instance_ctx(inst));
128 err = PTR_ERR(child);
129 if (IS_ERR(child))
130 goto out;
131
132 ctx->child = child;
133 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
134 sizeof(struct aead_request));
135
136 err = 0;
137
138 out:
139 return err;
140 }
141 EXPORT_SYMBOL_GPL(aead_init_geniv);
142
aead_exit_geniv(struct crypto_aead * tfm)143 void aead_exit_geniv(struct crypto_aead *tfm)
144 {
145 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
146
147 crypto_free_aead(ctx->child);
148 }
149 EXPORT_SYMBOL_GPL(aead_exit_geniv);
150
151 MODULE_LICENSE("GPL");
152 MODULE_DESCRIPTION("Shared IV generator code");
153