Merge drm/drm-next into drm-intel-next
[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 || err == -EBUSY)
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(void *data, int err)
40 {
41         struct aead_request *req = data;
42
43         seqiv_aead_encrypt_complete2(req, err);
44         aead_request_complete(req, err);
45 }
46
47 static int seqiv_aead_encrypt(struct aead_request *req)
48 {
49         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
50         struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
51         struct aead_request *subreq = aead_request_ctx(req);
52         crypto_completion_t compl;
53         void *data;
54         u8 *info;
55         unsigned int ivsize = 8;
56         int err;
57
58         if (req->cryptlen < ivsize)
59                 return -EINVAL;
60
61         aead_request_set_tfm(subreq, ctx->child);
62
63         compl = req->base.complete;
64         data = req->base.data;
65         info = req->iv;
66
67         if (req->src != req->dst) {
68                 SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
69
70                 skcipher_request_set_sync_tfm(nreq, ctx->sknull);
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);
78                 if (err)
79                         return err;
80         }
81
82         if (unlikely(!IS_ALIGNED((unsigned long)info,
83                                  crypto_aead_alignmask(geniv) + 1))) {
84                 info = kmemdup(req->iv, ivsize, req->base.flags &
85                                CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
86                                GFP_ATOMIC);
87                 if (!info)
88                         return -ENOMEM;
89
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);
97         aead_request_set_ad(subreq, req->assoclen + ivsize);
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
108 static int seqiv_aead_decrypt(struct aead_request *req)
109 {
110         struct crypto_aead *geniv = crypto_aead_reqtfm(req);
111         struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
112         struct aead_request *subreq = aead_request_ctx(req);
113         crypto_completion_t compl;
114         void *data;
115         unsigned int ivsize = 8;
116
117         if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
118                 return -EINVAL;
119
120         aead_request_set_tfm(subreq, ctx->child);
121
122         compl = req->base.complete;
123         data = req->base.data;
124
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);
128         aead_request_set_ad(subreq, req->assoclen + ivsize);
129
130         scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
131
132         return crypto_aead_decrypt(subreq);
133 }
134
135 static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
136 {
137         struct aead_instance *inst;
138         int err;
139
140         inst = aead_geniv_alloc(tmpl, tb);
141
142         if (IS_ERR(inst))
143                 return PTR_ERR(inst);
144
145         err = -EINVAL;
146         if (inst->alg.ivsize != sizeof(u64))
147                 goto free_inst;
148
149         inst->alg.encrypt = seqiv_aead_encrypt;
150         inst->alg.decrypt = seqiv_aead_decrypt;
151
152         inst->alg.init = aead_init_geniv;
153         inst->alg.exit = aead_exit_geniv;
154
155         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
156         inst->alg.base.cra_ctxsize += inst->alg.ivsize;
157
158         err = aead_register_instance(tmpl, inst);
159         if (err) {
160 free_inst:
161                 inst->free(inst);
162         }
163         return err;
164 }
165
166 static struct crypto_template seqiv_tmpl = {
167         .name = "seqiv",
168         .create = seqiv_aead_create,
169         .module = THIS_MODULE,
170 };
171
172 static int __init seqiv_module_init(void)
173 {
174         return crypto_register_template(&seqiv_tmpl);
175 }
176
177 static void __exit seqiv_module_exit(void)
178 {
179         crypto_unregister_template(&seqiv_tmpl);
180 }
181
182 subsys_initcall(seqiv_module_init);
183 module_exit(seqiv_module_exit);
184
185 MODULE_LICENSE("GPL");
186 MODULE_DESCRIPTION("Sequence Number IV Generator");
187 MODULE_ALIAS_CRYPTO("seqiv");