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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 <[email protected]>
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
18static 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
26static 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
34static void aead_geniv_free(struct aead_instance *inst)
35{
36 crypto_drop_aead(aead_instance_ctx(inst));
37 kfree(inst);
38}
39
40struct 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
98out:
99 return inst;
100
101err_free_inst:
102 aead_geniv_free(inst);
103 inst = ERR_PTR(err);
104 goto out;
105}
106EXPORT_SYMBOL_GPL(aead_geniv_alloc);
107
108int 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 err = crypto_stdrng_get_bytes(ctx->salt, crypto_aead_ivsize(aead));
116 if (err)
117 goto out;
118
119 child = crypto_spawn_aead(aead_instance_ctx(inst));
120 err = PTR_ERR(child);
121 if (IS_ERR(child))
122 goto out;
123
124 ctx->child = child;
125 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
126 sizeof(struct aead_request));
127
128 err = 0;
129
130out:
131 return err;
132}
133EXPORT_SYMBOL_GPL(aead_init_geniv);
134
135void aead_exit_geniv(struct crypto_aead *tfm)
136{
137 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
138
139 crypto_free_aead(ctx->child);
140}
141EXPORT_SYMBOL_GPL(aead_exit_geniv);
142
143MODULE_LICENSE("GPL");
144MODULE_DESCRIPTION("Shared IV generator code");