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
 
 
 21static 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
 35out:
 36	kfree_sensitive(subreq->iv);
 37}
 38
 39static 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
 48static 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
109static 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
136static 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) {
161free_inst:
162		inst->free(inst);
163	}
164	return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
165}
166
167static struct crypto_template seqiv_tmpl = {
168	.name = "seqiv",
169	.create = seqiv_aead_create,
 
170	.module = THIS_MODULE,
171};
172
173static int __init seqiv_module_init(void)
174{
175	return crypto_register_template(&seqiv_tmpl);
176}
177
178static void __exit seqiv_module_exit(void)
179{
180	crypto_unregister_template(&seqiv_tmpl);
181}
182
183subsys_initcall(seqiv_module_init);
184module_exit(seqiv_module_exit);
185
186MODULE_LICENSE("GPL");
187MODULE_DESCRIPTION("Sequence Number IV Generator");
188MODULE_ALIAS_CRYPTO("seqiv");

  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
 21static void seqiv_free(struct crypto_instance *inst);
 22
 23static void seqiv_aead_encrypt_complete2(struct aead_request *req, int err)
 24{
 25	struct aead_request *subreq = aead_request_ctx(req);
 26	struct crypto_aead *geniv;
 27
 28	if (err == -EINPROGRESS)
 29		return;
 30
 31	if (err)
 32		goto out;
 33
 34	geniv = crypto_aead_reqtfm(req);
 35	memcpy(req->iv, subreq->iv, crypto_aead_ivsize(geniv));
 36
 37out:
 38	kzfree(subreq->iv);
 39}
 40
 41static void seqiv_aead_encrypt_complete(struct crypto_async_request *base,
 42					int err)
 43{
 44	struct aead_request *req = base->data;
 45
 46	seqiv_aead_encrypt_complete2(req, err);
 47	aead_request_complete(req, err);
 48}
 49
 50static int seqiv_aead_encrypt(struct aead_request *req)
 51{
 52	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
 53	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
 54	struct aead_request *subreq = aead_request_ctx(req);
 55	crypto_completion_t compl;
 56	void *data;
 57	u8 *info;
 58	unsigned int ivsize = 8;
 59	int err;
 60
 61	if (req->cryptlen < ivsize)
 62		return -EINVAL;
 63
 64	aead_request_set_tfm(subreq, ctx->child);
 65
 66	compl = req->base.complete;
 67	data = req->base.data;
 68	info = req->iv;
 69
 70	if (req->src != req->dst) {
 71		SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->sknull);
 72
 73		skcipher_request_set_sync_tfm(nreq, ctx->sknull);
 74		skcipher_request_set_callback(nreq, req->base.flags,
 75					      NULL, NULL);
 76		skcipher_request_set_crypt(nreq, req->src, req->dst,
 77					   req->assoclen + req->cryptlen,
 78					   NULL);
 79
 80		err = crypto_skcipher_encrypt(nreq);
 81		if (err)
 82			return err;
 83	}
 84
 85	if (unlikely(!IS_ALIGNED((unsigned long)info,
 86				 crypto_aead_alignmask(geniv) + 1))) {
 87		info = kmemdup(req->iv, ivsize, req->base.flags &
 88			       CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL :
 89			       GFP_ATOMIC);
 90		if (!info)
 91			return -ENOMEM;
 92
 93		compl = seqiv_aead_encrypt_complete;
 94		data = req;
 95	}
 96
 97	aead_request_set_callback(subreq, req->base.flags, compl, data);
 98	aead_request_set_crypt(subreq, req->dst, req->dst,
 99			       req->cryptlen - ivsize, info);
100	aead_request_set_ad(subreq, req->assoclen + ivsize);
101
102	crypto_xor(info, ctx->salt, ivsize);
103	scatterwalk_map_and_copy(info, req->dst, req->assoclen, ivsize, 1);
104
105	err = crypto_aead_encrypt(subreq);
106	if (unlikely(info != req->iv))
107		seqiv_aead_encrypt_complete2(req, err);
108	return err;
109}
110
111static int seqiv_aead_decrypt(struct aead_request *req)
112{
113	struct crypto_aead *geniv = crypto_aead_reqtfm(req);
114	struct aead_geniv_ctx *ctx = crypto_aead_ctx(geniv);
115	struct aead_request *subreq = aead_request_ctx(req);
116	crypto_completion_t compl;
117	void *data;
118	unsigned int ivsize = 8;
119
120	if (req->cryptlen < ivsize + crypto_aead_authsize(geniv))
121		return -EINVAL;
122
123	aead_request_set_tfm(subreq, ctx->child);
124
125	compl = req->base.complete;
126	data = req->base.data;
127
128	aead_request_set_callback(subreq, req->base.flags, compl, data);
129	aead_request_set_crypt(subreq, req->src, req->dst,
130			       req->cryptlen - ivsize, req->iv);
131	aead_request_set_ad(subreq, req->assoclen + ivsize);
132
133	scatterwalk_map_and_copy(req->iv, req->src, req->assoclen, ivsize, 0);
134
135	return crypto_aead_decrypt(subreq);
136}
137
138static int seqiv_aead_create(struct crypto_template *tmpl, struct rtattr **tb)
139{
140	struct aead_instance *inst;
141	int err;
142
143	inst = aead_geniv_alloc(tmpl, tb, 0, 0);
144
145	if (IS_ERR(inst))
146		return PTR_ERR(inst);
147
148	err = -EINVAL;
149	if (inst->alg.ivsize != sizeof(u64))
150		goto free_inst;
151
152	inst->alg.encrypt = seqiv_aead_encrypt;
153	inst->alg.decrypt = seqiv_aead_decrypt;
154
155	inst->alg.init = aead_init_geniv;
156	inst->alg.exit = aead_exit_geniv;
157
158	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
159	inst->alg.base.cra_ctxsize += inst->alg.ivsize;
160
161	err = aead_register_instance(tmpl, inst);
162	if (err)
163		goto free_inst;
164
165out:
166	return err;
167
168free_inst:
169	aead_geniv_free(inst);
170	goto out;
171}
172
173static int seqiv_create(struct crypto_template *tmpl, struct rtattr **tb)
174{
175	struct crypto_attr_type *algt;
176
177	algt = crypto_get_attr_type(tb);
178	if (IS_ERR(algt))
179		return PTR_ERR(algt);
180
181	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & CRYPTO_ALG_TYPE_MASK)
182		return -EINVAL;
183
184	return seqiv_aead_create(tmpl, tb);
185}
186
187static void seqiv_free(struct crypto_instance *inst)
188{
189	aead_geniv_free(aead_instance(inst));
190}
191
192static struct crypto_template seqiv_tmpl = {
193	.name = "seqiv",
194	.create = seqiv_create,
195	.free = seqiv_free,
196	.module = THIS_MODULE,
197};
198
199static int __init seqiv_module_init(void)
200{
201	return crypto_register_template(&seqiv_tmpl);
202}
203
204static void __exit seqiv_module_exit(void)
205{
206	crypto_unregister_template(&seqiv_tmpl);
207}
208
209subsys_initcall(seqiv_module_init);
210module_exit(seqiv_module_exit);
211
212MODULE_LICENSE("GPL");
213MODULE_DESCRIPTION("Sequence Number IV Generator");
214MODULE_ALIAS_CRYPTO("seqiv");