Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
[platform/kernel/linux-starfive.git] / crypto / seqiv.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
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>
9  */
10
11 #include <crypto/internal/geniv.h>
12 #include <crypto/scatterwalk.h>
13 #include <crypto/skcipher.h>
14 #include <linux/err.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20
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
26         if (err == -EINPROGRESS)
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:
36         kfree_sensitive(subreq->iv);
37 }
38
39 static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
40                                         int err)
41 {
42         struct aead_request *req = base->data;
43
44         seqiv_aead_encrypt_complete2(req, err);
45         aead_request_complete(req, err);
46 }
47
48 static int seqiv_aead_encrypt(struct aead_request *req)
49 {
50         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
51         struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
52         struct aead_request *subreq = aead_request_ctx(req);
53         crypto_completion_t compl;
54         void *data;
55         u8 *info;
56         unsigned int ivsize = 8;
57         int err;
58
59         if (req->cryptlen < ivsize)
60                 return -EINVAL;
61
62         aead_request_set_tfm(subreq, ctx->child);
63
64         compl = req->base.complete;
65         data = req->base.data;
66         info = req->iv;
67
68         if (req->src != req->dst) {
69                 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
70
71                 skcipher_request_set_sync_tfm(nreq, ctx->sknull);
72                 skcipher_request_set_callback(nreq, req->base.flags,
73                                               NULL, NULL);
74                 skcipher_request_set_crypt(nreq, req->src, req->dst,
75                                            req->assoclen + req->cryptlen,
76                                            NULL);
77
78                 err = crypto_skcipher_encrypt(nreq);
79                 if (err)
80                         return err;
81         }
82
83         if (unlikely(!IS_ALIGNED((unsigned long)info,
84                                  crypto_aead_alignmask(geniv) + 1))) {
85                 info = kmemdup(req->iv, ivsize, req->base.flags &
86                                CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
87                                GFP_ATOMIC);
88                 if (!info)
89                         return -ENOMEM;
90
91                 compl = seqiv_aead_encrypt_complete;
92                 data = req;
93         }
94
95         aead_request_set_callback(subreq, req->base.flags, compl, data);
96         aead_request_set_crypt(subreq, req->dst, req->dst,
97                                req->cryptlen - ivsize, info);
98         aead_request_set_ad(subreq, req->assoclen + ivsize);
99
100         crypto_xor(info, ctx->salt, ivsize);
101         scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
102
103         err = crypto_aead_encrypt(subreq);
104         if (unlikely(info != req->iv))
105                 seqiv_aead_encrypt_complete2(req, err);
106         return err;
107 }
108
109 static int seqiv_aead_decrypt(struct aead_request *req)
110 {
111         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
112         struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
113         struct aead_request *subreq = aead_request_ctx(req);
114         crypto_completion_t compl;
115         void *data;
116         unsigned int ivsize = 8;
117
118         if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
119                 return -EINVAL;
120
121         aead_request_set_tfm(subreq, ctx->child);
122
123         compl = req->base.complete;
124         data = req->base.data;
125
126         aead_request_set_callback(subreq, req->base.flags, compl, data);
127         aead_request_set_crypt(subreq, req->src, req->dst,
128                                req->cryptlen - ivsize, req->iv);
129         aead_request_set_ad(subreq, req->assoclen + ivsize);
130
131         scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
132
133         return crypto_aead_decrypt(subreq);
134 }
135
136 static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
137 {
138         struct aead_instance *inst;
139         int err;
140
141         inst = aead_geniv_alloc(tmpl, tb);
142
143         if (IS_ERR(inst))
144                 return PTR_ERR(inst);
145
146         err = -EINVAL;
147         if (inst->alg.ivsize != sizeof(u64))
148                 goto free_inst;
149
150         inst->alg.encrypt = seqiv_aead_encrypt;
151         inst->alg.decrypt = seqiv_aead_decrypt;
152
153         inst->alg.init = aead_init_geniv;
154         inst->alg.exit = aead_exit_geniv;
155
156         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
157         inst->alg.base.cra_ctxsize += inst->alg.ivsize;
158
159         err = aead_register_instance(tmpl, inst);
160         if (err) {
161 free_inst:
162                 inst->free(inst);
163         }
164         return err;
165 }
166
167 static struct crypto_template seqiv_tmpl = {
168         .name = "seqiv",
169         .create = seqiv_aead_create,
170         .module = THIS_MODULE,
171 };
172
173 static int __init seqiv_module_init(void)
174 {
175         return crypto_register_template(&seqiv_tmpl);
176 }
177
178 static void __exit seqiv_module_exit(void)
179 {
180         crypto_unregister_template(&seqiv_tmpl);
181 }
182
183 subsys_initcall(seqiv_module_init);
184 module_exit(seqiv_module_exit);
185
186 MODULE_LICENSE("GPL");
187 MODULE_DESCRIPTION("Sequence Number IV Generator");
188 MODULE_ALIAS_CRYPTO("seqiv");