1/*
  2 * Cryptographic API.
  3 *
  4 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
  5 *
  6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  7 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  8 *
  9 * The HMAC implementation is derived from USAGI.
 10 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
 11 *
 12 * This program is free software; you can redistribute it and/or modify it
 13 * under the terms of the GNU General Public License as published by the Free
 14 * Software Foundation; either version 2 of the License, or (at your option)
 15 * any later version.
 16 *
 17 */
 18
 
 19#include <crypto/internal/hash.h>
 20#include <crypto/scatterwalk.h>
 21#include <linux/err.h>
 
 22#include <linux/init.h>
 23#include <linux/kernel.h>
 24#include <linux/module.h>
 25#include <linux/scatterlist.h>
 26#include <linux/string.h>
 27
 28struct hmac_ctx {
 29	struct crypto_shash *hash;
 
 
 30};
 31
 32static inline void *align_ptr(void *p, unsigned int align)
 33{
 34	return (void *)ALIGN((unsigned long)p, align);
 35}
 36
 37static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
 38{
 39	return align_ptr(crypto_shash_ctx_aligned(tfm) +
 40			 crypto_shash_statesize(tfm) * 2,
 41			 crypto_tfm_ctx_alignment());
 42}
 43
 44static int hmac_setkey(struct crypto_shash *parent,
 45		       const u8 *inkey, unsigned int keylen)
 46{
 47	int bs = crypto_shash_blocksize(parent);
 48	int ds = crypto_shash_digestsize(parent);
 49	int ss = crypto_shash_statesize(parent);
 50	char *ipad = crypto_shash_ctx_aligned(parent);
 51	char *opad = ipad + ss;
 52	struct hmac_ctx *ctx = align_ptr(opad + ss,
 53					 crypto_tfm_ctx_alignment());
 54	struct crypto_shash *hash = ctx->hash;
 55	SHASH_DESC_ON_STACK(shash, hash);
 56	unsigned int i;
 57
 
 
 
 58	shash->tfm = hash;
 59	shash->flags = crypto_shash_get_flags(parent)
 60		& CRYPTO_TFM_REQ_MAY_SLEEP;
 61
 62	if (keylen > bs) {
 63		int err;
 64
 65		err = crypto_shash_digest(shash, inkey, keylen, ipad);
 66		if (err)
 67			return err;
 68
 69		keylen = ds;
 70	} else
 71		memcpy(ipad, inkey, keylen);
 72
 73	memset(ipad + keylen, 0, bs - keylen);
 74	memcpy(opad, ipad, bs);
 75
 76	for (i = 0; i < bs; i++) {
 77		ipad[i] ^= 0x36;
 78		opad[i] ^= 0x5c;
 79	}
 80
 81	return crypto_shash_init(shash) ?:
 82	       crypto_shash_update(shash, ipad, bs) ?:
 83	       crypto_shash_export(shash, ipad) ?:
 84	       crypto_shash_init(shash) ?:
 85	       crypto_shash_update(shash, opad, bs) ?:
 86	       crypto_shash_export(shash, opad);
 87}
 88
 89static int hmac_export(struct shash_desc *pdesc, void *out)
 90{
 91	struct shash_desc *desc = shash_desc_ctx(pdesc);
 92
 93	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 94
 95	return crypto_shash_export(desc, out);
 96}
 97
 98static int hmac_import(struct shash_desc *pdesc, const void *in)
 99{
100	struct shash_desc *desc = shash_desc_ctx(pdesc);
101	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
102
103	desc->tfm = ctx->hash;
104	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
105
106	return crypto_shash_import(desc, in);
107}
108
109static int hmac_init(struct shash_desc *pdesc)
110{
111	return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
 
 
112}
113
114static int hmac_update(struct shash_desc *pdesc,
115		       const u8 *data, unsigned int nbytes)
116{
117	struct shash_desc *desc = shash_desc_ctx(pdesc);
118
119	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
120
121	return crypto_shash_update(desc, data, nbytes);
122}
123
124static int hmac_final(struct shash_desc *pdesc, u8 *out)
125{
126	struct crypto_shash *parent = pdesc->tfm;
127	int ds = crypto_shash_digestsize(parent);
128	int ss = crypto_shash_statesize(parent);
129	char *opad = crypto_shash_ctx_aligned(parent) + ss;
 
130	struct shash_desc *desc = shash_desc_ctx(pdesc);
131
132	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
133
134	return crypto_shash_final(desc, out) ?:
135	       crypto_shash_import(desc, opad) ?:
136	       crypto_shash_finup(desc, out, ds, out);
137}
138
139static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
140		      unsigned int nbytes, u8 *out)
141{
142
143	struct crypto_shash *parent = pdesc->tfm;
144	int ds = crypto_shash_digestsize(parent);
145	int ss = crypto_shash_statesize(parent);
146	char *opad = crypto_shash_ctx_aligned(parent) + ss;
 
147	struct shash_desc *desc = shash_desc_ctx(pdesc);
148
149	desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
150
151	return crypto_shash_finup(desc, data, nbytes, out) ?:
152	       crypto_shash_import(desc, opad) ?:
153	       crypto_shash_finup(desc, out, ds, out);
154}
155
156static int hmac_init_tfm(struct crypto_tfm *tfm)
157{
158	struct crypto_shash *parent = __crypto_shash_cast(tfm);
159	struct crypto_shash *hash;
160	struct crypto_instance *inst = (void *)tfm->__crt_alg;
161	struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
162	struct hmac_ctx *ctx = hmac_ctx(parent);
163
164	hash = crypto_spawn_shash(spawn);
165	if (IS_ERR(hash))
166		return PTR_ERR(hash);
167
168	parent->descsize = sizeof(struct shash_desc) +
169			   crypto_shash_descsize(hash);
170
171	ctx->hash = hash;
172	return 0;
173}
174
175static void hmac_exit_tfm(struct crypto_tfm *tfm)
176{
177	struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
178	crypto_free_shash(ctx->hash);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
179}
180
181static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
182{
183	struct shash_instance *inst;
 
184	struct crypto_alg *alg;
185	struct shash_alg *salg;
 
186	int err;
187	int ds;
188	int ss;
189
190	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
191	if (err)
192		return err;
193
194	salg = shash_attr_alg(tb[1], 0, 0);
195	if (IS_ERR(salg))
196		return PTR_ERR(salg);
 
 
 
 
 
 
 
 
197
 
198	err = -EINVAL;
 
 
 
199	ds = salg->digestsize;
200	ss = salg->statesize;
201	alg = &salg->base;
202	if (ds > alg->cra_blocksize ||
203	    ss < alg->cra_blocksize)
204		goto out_put_alg;
205
206	inst = shash_alloc_instance("hmac", alg);
207	err = PTR_ERR(inst);
208	if (IS_ERR(inst))
209		goto out_put_alg;
210
211	err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
212				      shash_crypto_instance(inst));
213	if (err)
214		goto out_free_inst;
215
216	inst->alg.base.cra_priority = alg->cra_priority;
217	inst->alg.base.cra_blocksize = alg->cra_blocksize;
218	inst->alg.base.cra_alignmask = alg->cra_alignmask;
219
220	ss = ALIGN(ss, alg->cra_alignmask + 1);
221	inst->alg.digestsize = ds;
222	inst->alg.statesize = ss;
223
224	inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
225				     ALIGN(ss * 2, crypto_tfm_ctx_alignment());
226
227	inst->alg.base.cra_init = hmac_init_tfm;
228	inst->alg.base.cra_exit = hmac_exit_tfm;
229
230	inst->alg.init = hmac_init;
231	inst->alg.update = hmac_update;
232	inst->alg.final = hmac_final;
233	inst->alg.finup = hmac_finup;
234	inst->alg.export = hmac_export;
235	inst->alg.import = hmac_import;
236	inst->alg.setkey = hmac_setkey;
 
 
 
 
 
237
238	err = shash_register_instance(tmpl, inst);
239	if (err) {
240out_free_inst:
241		shash_free_instance(shash_crypto_instance(inst));
242	}
243
244out_put_alg:
245	crypto_mod_put(alg);
246	return err;
247}
248
249static struct crypto_template hmac_tmpl = {
250	.name = "hmac",
251	.create = hmac_create,
252	.free = shash_free_instance,
253	.module = THIS_MODULE,
254};
255
256static int __init hmac_module_init(void)
257{
258	return crypto_register_template(&hmac_tmpl);
259}
260
261static void __exit hmac_module_exit(void)
262{
263	crypto_unregister_template(&hmac_tmpl);
264}
265
266module_init(hmac_module_init);
267module_exit(hmac_module_exit);
268
269MODULE_LICENSE("GPL");
270MODULE_DESCRIPTION("HMAC hash algorithm");
271MODULE_ALIAS_CRYPTO("hmac");

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Cryptographic API.
  4 *
  5 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
  6 *
  7 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  9 *
 10 * The HMAC implementation is derived from USAGI.
 11 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
 
 
 
 
 
 
 12 */
 13
 14#include <crypto/hmac.h>
 15#include <crypto/internal/hash.h>
 16#include <crypto/scatterwalk.h>
 17#include <linux/err.h>
 18#include <linux/fips.h>
 19#include <linux/init.h>
 20#include <linux/kernel.h>
 21#include <linux/module.h>
 22#include <linux/scatterlist.h>
 23#include <linux/string.h>
 24
 25struct hmac_ctx {
 26	struct crypto_shash *hash;
 27	/* Contains 'u8 ipad[statesize];', then 'u8 opad[statesize];' */
 28	u8 pads[];
 29};
 30
 
 
 
 
 
 
 
 
 
 
 
 
 31static int hmac_setkey(struct crypto_shash *parent,
 32		       const u8 *inkey, unsigned int keylen)
 33{
 34	int bs = crypto_shash_blocksize(parent);
 35	int ds = crypto_shash_digestsize(parent);
 36	int ss = crypto_shash_statesize(parent);
 37	struct hmac_ctx *tctx = crypto_shash_ctx(parent);
 38	struct crypto_shash *hash = tctx->hash;
 39	u8 *ipad = &tctx->pads[0];
 40	u8 *opad = &tctx->pads[ss];
 
 41	SHASH_DESC_ON_STACK(shash, hash);
 42	unsigned int i;
 43
 44	if (fips_enabled && (keylen < 112 / 8))
 45		return -EINVAL;
 46
 47	shash->tfm = hash;
 
 
 48
 49	if (keylen > bs) {
 50		int err;
 51
 52		err = crypto_shash_digest(shash, inkey, keylen, ipad);
 53		if (err)
 54			return err;
 55
 56		keylen = ds;
 57	} else
 58		memcpy(ipad, inkey, keylen);
 59
 60	memset(ipad + keylen, 0, bs - keylen);
 61	memcpy(opad, ipad, bs);
 62
 63	for (i = 0; i < bs; i++) {
 64		ipad[i] ^= HMAC_IPAD_VALUE;
 65		opad[i] ^= HMAC_OPAD_VALUE;
 66	}
 67
 68	return crypto_shash_init(shash) ?:
 69	       crypto_shash_update(shash, ipad, bs) ?:
 70	       crypto_shash_export(shash, ipad) ?:
 71	       crypto_shash_init(shash) ?:
 72	       crypto_shash_update(shash, opad, bs) ?:
 73	       crypto_shash_export(shash, opad);
 74}
 75
 76static int hmac_export(struct shash_desc *pdesc, void *out)
 77{
 78	struct shash_desc *desc = shash_desc_ctx(pdesc);
 79
 
 
 80	return crypto_shash_export(desc, out);
 81}
 82
 83static int hmac_import(struct shash_desc *pdesc, const void *in)
 84{
 85	struct shash_desc *desc = shash_desc_ctx(pdesc);
 86	const struct hmac_ctx *tctx = crypto_shash_ctx(pdesc->tfm);
 87
 88	desc->tfm = tctx->hash;
 
 89
 90	return crypto_shash_import(desc, in);
 91}
 92
 93static int hmac_init(struct shash_desc *pdesc)
 94{
 95	const struct hmac_ctx *tctx = crypto_shash_ctx(pdesc->tfm);
 96
 97	return hmac_import(pdesc, &tctx->pads[0]);
 98}
 99
100static int hmac_update(struct shash_desc *pdesc,
101		       const u8 *data, unsigned int nbytes)
102{
103	struct shash_desc *desc = shash_desc_ctx(pdesc);
104
 
 
105	return crypto_shash_update(desc, data, nbytes);
106}
107
108static int hmac_final(struct shash_desc *pdesc, u8 *out)
109{
110	struct crypto_shash *parent = pdesc->tfm;
111	int ds = crypto_shash_digestsize(parent);
112	int ss = crypto_shash_statesize(parent);
113	const struct hmac_ctx *tctx = crypto_shash_ctx(parent);
114	const u8 *opad = &tctx->pads[ss];
115	struct shash_desc *desc = shash_desc_ctx(pdesc);
116
 
 
117	return crypto_shash_final(desc, out) ?:
118	       crypto_shash_import(desc, opad) ?:
119	       crypto_shash_finup(desc, out, ds, out);
120}
121
122static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
123		      unsigned int nbytes, u8 *out)
124{
125
126	struct crypto_shash *parent = pdesc->tfm;
127	int ds = crypto_shash_digestsize(parent);
128	int ss = crypto_shash_statesize(parent);
129	const struct hmac_ctx *tctx = crypto_shash_ctx(parent);
130	const u8 *opad = &tctx->pads[ss];
131	struct shash_desc *desc = shash_desc_ctx(pdesc);
132
 
 
133	return crypto_shash_finup(desc, data, nbytes, out) ?:
134	       crypto_shash_import(desc, opad) ?:
135	       crypto_shash_finup(desc, out, ds, out);
136}
137
138static int hmac_init_tfm(struct crypto_shash *parent)
139{
 
140	struct crypto_shash *hash;
141	struct shash_instance *inst = shash_alg_instance(parent);
142	struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
143	struct hmac_ctx *tctx = crypto_shash_ctx(parent);
144
145	hash = crypto_spawn_shash(spawn);
146	if (IS_ERR(hash))
147		return PTR_ERR(hash);
148
149	parent->descsize = sizeof(struct shash_desc) +
150			   crypto_shash_descsize(hash);
151
152	tctx->hash = hash;
153	return 0;
154}
155
156static int hmac_clone_tfm(struct crypto_shash *dst, struct crypto_shash *src)
157{
158	struct hmac_ctx *sctx = crypto_shash_ctx(src);
159	struct hmac_ctx *dctx = crypto_shash_ctx(dst);
160	struct crypto_shash *hash;
161
162	hash = crypto_clone_shash(sctx->hash);
163	if (IS_ERR(hash))
164		return PTR_ERR(hash);
165
166	dctx->hash = hash;
167	return 0;
168}
169
170static void hmac_exit_tfm(struct crypto_shash *parent)
171{
172	struct hmac_ctx *tctx = crypto_shash_ctx(parent);
173
174	crypto_free_shash(tctx->hash);
175}
176
177static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
178{
179	struct shash_instance *inst;
180	struct crypto_shash_spawn *spawn;
181	struct crypto_alg *alg;
182	struct shash_alg *salg;
183	u32 mask;
184	int err;
185	int ds;
186	int ss;
187
188	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
189	if (err)
190		return err;
191
192	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
193	if (!inst)
194		return -ENOMEM;
195	spawn = shash_instance_ctx(inst);
196
197	err = crypto_grab_shash(spawn, shash_crypto_instance(inst),
198				crypto_attr_alg_name(tb[1]), 0, mask);
199	if (err)
200		goto err_free_inst;
201	salg = crypto_spawn_shash_alg(spawn);
202	alg = &salg->base;
203
204	/* The underlying hash algorithm must not require a key */
205	err = -EINVAL;
206	if (crypto_shash_alg_needs_key(salg))
207		goto err_free_inst;
208
209	ds = salg->digestsize;
210	ss = salg->statesize;
 
211	if (ds > alg->cra_blocksize ||
212	    ss < alg->cra_blocksize)
213		goto err_free_inst;
214
215	err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
 
 
 
 
 
 
216	if (err)
217		goto err_free_inst;
218
219	inst->alg.base.cra_priority = alg->cra_priority;
220	inst->alg.base.cra_blocksize = alg->cra_blocksize;
221	inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) + (ss * 2);
222
 
223	inst->alg.digestsize = ds;
224	inst->alg.statesize = ss;
 
 
 
 
 
 
 
225	inst->alg.init = hmac_init;
226	inst->alg.update = hmac_update;
227	inst->alg.final = hmac_final;
228	inst->alg.finup = hmac_finup;
229	inst->alg.export = hmac_export;
230	inst->alg.import = hmac_import;
231	inst->alg.setkey = hmac_setkey;
232	inst->alg.init_tfm = hmac_init_tfm;
233	inst->alg.clone_tfm = hmac_clone_tfm;
234	inst->alg.exit_tfm = hmac_exit_tfm;
235
236	inst->free = shash_free_singlespawn_instance;
237
238	err = shash_register_instance(tmpl, inst);
239	if (err) {
240err_free_inst:
241		shash_free_singlespawn_instance(inst);
242	}
 
 
 
243	return err;
244}
245
246static struct crypto_template hmac_tmpl = {
247	.name = "hmac",
248	.create = hmac_create,
 
249	.module = THIS_MODULE,
250};
251
252static int __init hmac_module_init(void)
253{
254	return crypto_register_template(&hmac_tmpl);
255}
256
257static void __exit hmac_module_exit(void)
258{
259	crypto_unregister_template(&hmac_tmpl);
260}
261
262subsys_initcall(hmac_module_init);
263module_exit(hmac_module_exit);
264
265MODULE_LICENSE("GPL");
266MODULE_DESCRIPTION("HMAC hash algorithm");
267MODULE_ALIAS_CRYPTO("hmac");