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16#include <crypto/internal/aead.h>
17#include <crypto/internal/skcipher.h>
18#include <crypto/rng.h>
19#include <linux/err.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25#include <linux/string.h>
26
27struct seqiv_ctx {
28 spinlock_t lock;
29 u8 salt[] __attribute__ ((aligned(__alignof__(u32))));
30};
31
32static void seqiv_complete2(struct skcipher_givcrypt_request *req, int err)
33{
34 struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);
35 struct crypto_ablkcipher *geniv;
36
37 if (err == -EINPROGRESS)
38 return;
39
40 if (err)
41 goto out;
42
43 geniv = skcipher_givcrypt_reqtfm(req);
44 memcpy(req->creq.info, subreq->info, crypto_ablkcipher_ivsize(geniv));
45
46out:
47 kfree(subreq->info);
48}
49
50static void seqiv_complete(struct crypto_async_request *base, int err)
51{
52 struct skcipher_givcrypt_request *req = base->data;
53
54 seqiv_complete2(req, err);
55 skcipher_givcrypt_complete(req, err);
56}
57
58static void seqiv_aead_complete2(struct aead_givcrypt_request *req, int err)
59{
60 struct aead_request *subreq = aead_givcrypt_reqctx(req);
61 struct crypto_aead *geniv;
62
63 if (err == -EINPROGRESS)
64 return;
65
66 if (err)
67 goto out;
68
69 geniv = aead_givcrypt_reqtfm(req);
70 memcpy(req->areq.iv, subreq->iv, crypto_aead_ivsize(geniv));
71
72out:
73 kfree(subreq->iv);
74}
75
76static void seqiv_aead_complete(struct crypto_async_request *base, int err)
77{
78 struct aead_givcrypt_request *req = base->data;
79
80 seqiv_aead_complete2(req, err);
81 aead_givcrypt_complete(req, err);
82}
83
84static void seqiv_geniv(struct seqiv_ctx *ctx, u8 *info, u64 seq,
85 unsigned int ivsize)
86{
87 unsigned int len = ivsize;
88
89 if (ivsize > sizeof(u64)) {
90 memset(info, 0, ivsize - sizeof(u64));
91 len = sizeof(u64);
92 }
93 seq = cpu_to_be64(seq);
94 memcpy(info + ivsize - len, &seq, len);
95 crypto_xor(info, ctx->salt, ivsize);
96}
97
98static int seqiv_givencrypt(struct skcipher_givcrypt_request *req)
99{
100 struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
101 struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
102 struct ablkcipher_request *subreq = skcipher_givcrypt_reqctx(req);
103 crypto_completion_t complete;
104 void *data;
105 u8 *info;
106 unsigned int ivsize;
107 int err;
108
109 ablkcipher_request_set_tfm(subreq, skcipher_geniv_cipher(geniv));
110
111 complete = req->creq.base.complete;
112 data = req->creq.base.data;
113 info = req->creq.info;
114
115 ivsize = crypto_ablkcipher_ivsize(geniv);
116
117 if (unlikely(!IS_ALIGNED((unsigned long)info,
118 crypto_ablkcipher_alignmask(geniv) + 1))) {
119 info = kmalloc(ivsize, req->creq.base.flags &
120 CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
121 GFP_ATOMIC);
122 if (!info)
123 return -ENOMEM;
124
125 complete = seqiv_complete;
126 data = req;
127 }
128
129 ablkcipher_request_set_callback(subreq, req->creq.base.flags, complete,
130 data);
131 ablkcipher_request_set_crypt(subreq, req->creq.src, req->creq.dst,
132 req->creq.nbytes, info);
133
134 seqiv_geniv(ctx, info, req->seq, ivsize);
135 memcpy(req->giv, info, ivsize);
136
137 err = crypto_ablkcipher_encrypt(subreq);
138 if (unlikely(info != req->creq.info))
139 seqiv_complete2(req, err);
140 return err;
141}
142
143static int seqiv_aead_givencrypt(struct aead_givcrypt_request *req)
144{
145 struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);
146 struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
147 struct aead_request *areq = &req->areq;
148 struct aead_request *subreq = aead_givcrypt_reqctx(req);
149 crypto_completion_t complete;
150 void *data;
151 u8 *info;
152 unsigned int ivsize;
153 int err;
154
155 aead_request_set_tfm(subreq, aead_geniv_base(geniv));
156
157 complete = areq->base.complete;
158 data = areq->base.data;
159 info = areq->iv;
160
161 ivsize = crypto_aead_ivsize(geniv);
162
163 if (unlikely(!IS_ALIGNED((unsigned long)info,
164 crypto_aead_alignmask(geniv) + 1))) {
165 info = kmalloc(ivsize, areq->base.flags &
166 CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
167 GFP_ATOMIC);
168 if (!info)
169 return -ENOMEM;
170
171 complete = seqiv_aead_complete;
172 data = req;
173 }
174
175 aead_request_set_callback(subreq, areq->base.flags, complete, data);
176 aead_request_set_crypt(subreq, areq->src, areq->dst, areq->cryptlen,
177 info);
178 aead_request_set_assoc(subreq, areq->assoc, areq->assoclen);
179
180 seqiv_geniv(ctx, info, req->seq, ivsize);
181 memcpy(req->giv, info, ivsize);
182
183 err = crypto_aead_encrypt(subreq);
184 if (unlikely(info != areq->iv))
185 seqiv_aead_complete2(req, err);
186 return err;
187}
188
189static int seqiv_givencrypt_first(struct skcipher_givcrypt_request *req)
190{
191 struct crypto_ablkcipher *geniv = skcipher_givcrypt_reqtfm(req);
192 struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
193 int err = 0;
194
195 spin_lock_bh(&ctx->lock);
196 if (crypto_ablkcipher_crt(geniv)->givencrypt != seqiv_givencrypt_first)
197 goto unlock;
198
199 crypto_ablkcipher_crt(geniv)->givencrypt = seqiv_givencrypt;
200 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
201 crypto_ablkcipher_ivsize(geniv));
202
203unlock:
204 spin_unlock_bh(&ctx->lock);
205
206 if (err)
207 return err;
208
209 return seqiv_givencrypt(req);
210}
211
212static int seqiv_aead_givencrypt_first(struct aead_givcrypt_request *req)
213{
214 struct crypto_aead *geniv = aead_givcrypt_reqtfm(req);
215 struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
216 int err = 0;
217
218 spin_lock_bh(&ctx->lock);
219 if (crypto_aead_crt(geniv)->givencrypt != seqiv_aead_givencrypt_first)
220 goto unlock;
221
222 crypto_aead_crt(geniv)->givencrypt = seqiv_aead_givencrypt;
223 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
224 crypto_aead_ivsize(geniv));
225
226unlock:
227 spin_unlock_bh(&ctx->lock);
228
229 if (err)
230 return err;
231
232 return seqiv_aead_givencrypt(req);
233}
234
235static int seqiv_init(struct crypto_tfm *tfm)
236{
237 struct crypto_ablkcipher *geniv = __crypto_ablkcipher_cast(tfm);
238 struct seqiv_ctx *ctx = crypto_ablkcipher_ctx(geniv);
239
240 spin_lock_init(&ctx->lock);
241
242 tfm->crt_ablkcipher.reqsize = sizeof(struct ablkcipher_request);
243
244 return skcipher_geniv_init(tfm);
245}
246
247static int seqiv_aead_init(struct crypto_tfm *tfm)
248{
249 struct crypto_aead *geniv = __crypto_aead_cast(tfm);
250 struct seqiv_ctx *ctx = crypto_aead_ctx(geniv);
251
252 spin_lock_init(&ctx->lock);
253
254 tfm->crt_aead.reqsize = sizeof(struct aead_request);
255
256 return aead_geniv_init(tfm);
257}
258
259static struct crypto_template seqiv_tmpl;
260
261static struct crypto_instance *seqiv_ablkcipher_alloc(struct rtattr **tb)
262{
263 struct crypto_instance *inst;
264
265 inst = skcipher_geniv_alloc(&seqiv_tmpl, tb, 0, 0);
266
267 if (IS_ERR(inst))
268 goto out;
269
270 inst->alg.cra_ablkcipher.givencrypt = seqiv_givencrypt_first;
271
272 inst->alg.cra_init = seqiv_init;
273 inst->alg.cra_exit = skcipher_geniv_exit;
274
275 inst->alg.cra_ctxsize += inst->alg.cra_ablkcipher.ivsize;
276
277out:
278 return inst;
279}
280
281static struct crypto_instance *seqiv_aead_alloc(struct rtattr **tb)
282{
283 struct crypto_instance *inst;
284
285 inst = aead_geniv_alloc(&seqiv_tmpl, tb, 0, 0);
286
287 if (IS_ERR(inst))
288 goto out;
289
290 inst->alg.cra_aead.givencrypt = seqiv_aead_givencrypt_first;
291
292 inst->alg.cra_init = seqiv_aead_init;
293 inst->alg.cra_exit = aead_geniv_exit;
294
295 inst->alg.cra_ctxsize = inst->alg.cra_aead.ivsize;
296
297out:
298 return inst;
299}
300
301static struct crypto_instance *seqiv_alloc(struct rtattr **tb)
302{
303 struct crypto_attr_type *algt;
304 struct crypto_instance *inst;
305 int err;
306
307 algt = crypto_get_attr_type(tb);
308 err = PTR_ERR(algt);
309 if (IS_ERR(algt))
310 return ERR_PTR(err);
311
312 err = crypto_get_default_rng();
313 if (err)
314 return ERR_PTR(err);
315
316 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
317 inst = seqiv_ablkcipher_alloc(tb);
318 else
319 inst = seqiv_aead_alloc(tb);
320
321 if (IS_ERR(inst))
322 goto put_rng;
323
324 inst->alg.cra_alignmask |= __alignof__(u32) - 1;
325 inst->alg.cra_ctxsize += sizeof(struct seqiv_ctx);
326
327out:
328 return inst;
329
330put_rng:
331 crypto_put_default_rng();
332 goto out;
333}
334
335static void seqiv_free(struct crypto_instance *inst)
336{
337 if ((inst->alg.cra_flags ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
338 skcipher_geniv_free(inst);
339 else
340 aead_geniv_free(inst);
341 crypto_put_default_rng();
342}
343
344static struct crypto_template seqiv_tmpl = {
345 .name = "seqiv",
346 .alloc = seqiv_alloc,
347 .free = seqiv_free,
348 .module = THIS_MODULE,
349};
350
351static int __init seqiv_module_init(void)
352{
353 return crypto_register_template(&seqiv_tmpl);
354}
355
356static void __exit seqiv_module_exit(void)
357{
358 crypto_unregister_template(&seqiv_tmpl);
359}
360
361module_init(seqiv_module_init);
362module_exit(seqiv_module_exit);
363
364MODULE_LICENSE("GPL");
365MODULE_DESCRIPTION("Sequence Number IV Generator");
366
