Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
0a270321 HX |
2 | /* |
3 | * seqiv: Sequence Number IV Generator | |
4 | * | |
5 | * This generator generates an IV based on a sequence number by xoring it | |
6 | * with a salt. This algorithm is mainly useful for CTR and similar modes. | |
7 | * | |
8 | * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> | |
0a270321 HX |
9 | */ |
10 | ||
661cfd0e | 11 | #include <crypto/internal/geniv.h> |
856e3f40 | 12 | #include <crypto/scatterwalk.h> |
3a01d0ee | 13 | #include <crypto/skcipher.h> |
0a270321 HX |
14 | #include <linux/err.h> |
15 | #include <linux/init.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
0a270321 HX |
19 | #include <linux/string.h> |
20 | ||
856e3f40 HX |
21 | static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err) |
22 | { | |
23 | struct aead_request *subreq = aead_request_ctx(req); | |
24 | struct crypto_aead *geniv; | |
25 | ||
32e62025 | 26 | if (err == -EINPROGRESS || err == -EBUSY) |
856e3f40 HX |
27 | return; |
28 | ||
29 | if (err) | |
30 | goto out; | |
31 | ||
32 | geniv = crypto_aead_reqtfm(req); | |
33 | memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv)); | |
34 | ||
35 | out: | |
453431a5 | 36 | kfree_sensitive(subreq->iv); |
856e3f40 HX |
37 | } |
38 | ||
255e48eb | 39 | static void seqiv_aead_encrypt_complete(void *data, int err) |
856e3f40 | 40 | { |
255e48eb | 41 | struct aead_request *req = data; |
856e3f40 HX |
42 | |
43 | seqiv_aead_encrypt_complete2(req, err); | |
44 | aead_request_complete(req, err); | |
45 | } | |
46 | ||
856e3f40 HX |
47 | static int seqiv_aead_encrypt(struct aead_request *req) |
48 | { | |
49 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
659e7f52 | 50 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv); |
856e3f40 HX |
51 | struct aead_request *subreq = aead_request_ctx(req); |
52 | crypto_completion_t compl; | |
53 | void *data; | |
54 | u8 *info; | |
dd04446e | 55 | unsigned int ivsize = 8; |
856e3f40 HX |
56 | int err; |
57 | ||
dd04446e HX |
58 | if (req->cryptlen < ivsize) |
59 | return -EINVAL; | |
60 | ||
659e7f52 | 61 | aead_request_set_tfm(subreq, ctx->child); |
856e3f40 HX |
62 | |
63 | compl = req->base.complete; | |
64 | data = req->base.data; | |
65 | info = req->iv; | |
66 | ||
856e3f40 | 67 | if (req->src != req->dst) { |
8d605398 | 68 | SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull); |
856e3f40 | 69 | |
8d605398 | 70 | skcipher_request_set_sync_tfm(nreq, ctx->sknull); |
ef22871f HX |
71 | skcipher_request_set_callback(nreq, req->base.flags, |
72 | NULL, NULL); | |
73 | skcipher_request_set_crypt(nreq, req->src, req->dst, | |
74 | req->assoclen + req->cryptlen, | |
75 | NULL); | |
76 | ||
77 | err = crypto_skcipher_encrypt(nreq); | |
856e3f40 HX |
78 | if (err) |
79 | return err; | |
80 | } | |
81 | ||
82 | if (unlikely(!IS_ALIGNED((unsigned long)info, | |
83 | crypto_aead_alignmask(geniv) + 1))) { | |
7e33d4d4 Y |
84 | info = kmemdup(req->iv, ivsize, req->base.flags & |
85 | CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : | |
86 | GFP_ATOMIC); | |
856e3f40 HX |
87 | if (!info) |
88 | return -ENOMEM; | |
89 | ||
856e3f40 HX |
90 | compl = seqiv_aead_encrypt_complete; |
91 | data = req; | |
92 | } | |
93 | ||
94 | aead_request_set_callback(subreq, req->base.flags, compl, data); | |
95 | aead_request_set_crypt(subreq, req->dst, req->dst, | |
96 | req->cryptlen - ivsize, info); | |
374d4ad1 | 97 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
98 | |
99 | crypto_xor(info, ctx->salt, ivsize); | |
100 | scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1); | |
101 | ||
102 | err = crypto_aead_encrypt(subreq); | |
103 | if (unlikely(info != req->iv)) | |
104 | seqiv_aead_encrypt_complete2(req, err); | |
105 | return err; | |
106 | } | |
107 | ||
856e3f40 HX |
108 | static int seqiv_aead_decrypt(struct aead_request *req) |
109 | { | |
110 | struct crypto_aead *geniv = crypto_aead_reqtfm(req); | |
659e7f52 | 111 | struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv); |
856e3f40 HX |
112 | struct aead_request *subreq = aead_request_ctx(req); |
113 | crypto_completion_t compl; | |
114 | void *data; | |
dd04446e HX |
115 | unsigned int ivsize = 8; |
116 | ||
117 | if (req->cryptlen < ivsize + crypto_aead_authsize(geniv)) | |
118 | return -EINVAL; | |
856e3f40 | 119 | |
659e7f52 | 120 | aead_request_set_tfm(subreq, ctx->child); |
856e3f40 HX |
121 | |
122 | compl = req->base.complete; | |
123 | data = req->base.data; | |
124 | ||
856e3f40 HX |
125 | aead_request_set_callback(subreq, req->base.flags, compl, data); |
126 | aead_request_set_crypt(subreq, req->src, req->dst, | |
127 | req->cryptlen - ivsize, req->iv); | |
374d4ad1 | 128 | aead_request_set_ad(subreq, req->assoclen + ivsize); |
856e3f40 HX |
129 | |
130 | scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0); | |
856e3f40 HX |
131 | |
132 | return crypto_aead_decrypt(subreq); | |
133 | } | |
134 | ||
0677157b | 135 | static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb) |
14df4d80 | 136 | { |
856e3f40 | 137 | struct aead_instance *inst; |
0677157b | 138 | int err; |
14df4d80 | 139 | |
e72b48c5 | 140 | inst = aead_geniv_alloc(tmpl, tb); |
14df4d80 HX |
141 | |
142 | if (IS_ERR(inst)) | |
0677157b HX |
143 | return PTR_ERR(inst); |
144 | ||
0677157b | 145 | err = -EINVAL; |
dd04446e | 146 | if (inst->alg.ivsize != sizeof(u64)) |
0677157b | 147 | goto free_inst; |
c0ecf891 | 148 | |
b7dcfab4 | 149 | inst->alg.encrypt = seqiv_aead_encrypt; |
856e3f40 | 150 | inst->alg.decrypt = seqiv_aead_decrypt; |
14df4d80 | 151 | |
659e7f52 HX |
152 | inst->alg.init = aead_init_geniv; |
153 | inst->alg.exit = aead_exit_geniv; | |
856e3f40 | 154 | |
659e7f52 | 155 | inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx); |
5964f26c | 156 | inst->alg.base.cra_ctxsize += inst->alg.ivsize; |
856e3f40 | 157 | |
0677157b | 158 | err = aead_register_instance(tmpl, inst); |
0f8f6d86 | 159 | if (err) { |
0677157b | 160 | free_inst: |
0f8f6d86 EB |
161 | inst->free(inst); |
162 | } | |
163 | return err; | |
14df4d80 HX |
164 | } |
165 | ||
0a270321 HX |
166 | static struct crypto_template seqiv_tmpl = { |
167 | .name = "seqiv", | |
4688111e | 168 | .create = seqiv_aead_create, |
0a270321 HX |
169 | .module = THIS_MODULE, |
170 | }; | |
171 | ||
172 | static int __init seqiv_module_init(void) | |
173 | { | |
8a2cd1c4 | 174 | return crypto_register_template(&seqiv_tmpl); |
0a270321 HX |
175 | } |
176 | ||
177 | static void __exit seqiv_module_exit(void) | |
178 | { | |
179 | crypto_unregister_template(&seqiv_tmpl); | |
180 | } | |
181 | ||
c4741b23 | 182 | subsys_initcall(seqiv_module_init); |
0a270321 HX |
183 | module_exit(seqiv_module_exit); |
184 | ||
185 | MODULE_LICENSE("GPL"); | |
186 | MODULE_DESCRIPTION("Sequence Number IV Generator"); | |
4943ba16 | 187 | MODULE_ALIAS_CRYPTO("seqiv"); |