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");

  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 || 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
 35out:
 36	kfree_sensitive(subreq->iv);
 37}
 38
 39static 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
 47static 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
108static 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
135static 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) {
 
 
 
 
 
160free_inst:
161		inst->free(inst);
162	}
163	return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
164}
165
166static struct crypto_template seqiv_tmpl = {
167	.name = "seqiv",
168	.create = seqiv_aead_create,
 
169	.module = THIS_MODULE,
170};
171
172static int __init seqiv_module_init(void)
173{
174	return crypto_register_template(&seqiv_tmpl);
175}
176
177static void __exit seqiv_module_exit(void)
178{
179	crypto_unregister_template(&seqiv_tmpl);
180}
181
182subsys_initcall(seqiv_module_init);
183module_exit(seqiv_module_exit);
184
185MODULE_LICENSE("GPL");
186MODULE_DESCRIPTION("Sequence Number IV Generator");
187MODULE_ALIAS_CRYPTO("seqiv");