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/init.h>
 19#include <linux/kernel.h>
 20#include <linux/module.h>
 21#include <linux/scatterlist.h>
 22#include <linux/string.h>
 23
 24struct hmac_ctx {
 25	struct crypto_shash *hash;
 26};
 27
 28static inline void *align_ptr(void *p, unsigned int align)
 29{
 30	return (void *)ALIGN((unsigned long)p, align);
 31}
 32
 33static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
 34{
 35	return align_ptr(crypto_shash_ctx_aligned(tfm) +
 36			 crypto_shash_statesize(tfm) * 2,
 37			 crypto_tfm_ctx_alignment());
 38}
 39
 40static int hmac_setkey(struct crypto_shash *parent,
 41		       const u8 *inkey, unsigned int keylen)
 42{
 43	int bs = crypto_shash_blocksize(parent);
 44	int ds = crypto_shash_digestsize(parent);
 45	int ss = crypto_shash_statesize(parent);
 46	char *ipad = crypto_shash_ctx_aligned(parent);
 47	char *opad = ipad + ss;
 48	struct hmac_ctx *ctx = align_ptr(opad + ss,
 49					 crypto_tfm_ctx_alignment());
 50	struct crypto_shash *hash = ctx->hash;
 51	SHASH_DESC_ON_STACK(shash, hash);
 52	unsigned int i;
 53
 54	shash->tfm = hash;
 55
 56	if (keylen > bs) {
 57		int err;
 58
 59		err = crypto_shash_digest(shash, inkey, keylen, ipad);
 60		if (err)
 61			return err;
 62
 63		keylen = ds;
 64	} else
 65		memcpy(ipad, inkey, keylen);
 66
 67	memset(ipad + keylen, 0, bs - keylen);
 68	memcpy(opad, ipad, bs);
 69
 70	for (i = 0; i < bs; i++) {
 71		ipad[i] ^= HMAC_IPAD_VALUE;
 72		opad[i] ^= HMAC_OPAD_VALUE;
 73	}
 74
 75	return crypto_shash_init(shash) ?:
 76	       crypto_shash_update(shash, ipad, bs) ?:
 77	       crypto_shash_export(shash, ipad) ?:
 78	       crypto_shash_init(shash) ?:
 79	       crypto_shash_update(shash, opad, bs) ?:
 80	       crypto_shash_export(shash, opad);
 81}
 82
 83static int hmac_export(struct shash_desc *pdesc, void *out)
 84{
 85	struct shash_desc *desc = shash_desc_ctx(pdesc);
 86
 87	return crypto_shash_export(desc, out);
 88}
 89
 90static int hmac_import(struct shash_desc *pdesc, const void *in)
 91{
 92	struct shash_desc *desc = shash_desc_ctx(pdesc);
 93	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
 94
 95	desc->tfm = ctx->hash;
 96
 97	return crypto_shash_import(desc, in);
 98}
 99
100static int hmac_init(struct shash_desc *pdesc)
101{
102	return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
103}
104
105static int hmac_update(struct shash_desc *pdesc,
106		       const u8 *data, unsigned int nbytes)
107{
108	struct shash_desc *desc = shash_desc_ctx(pdesc);
109
110	return crypto_shash_update(desc, data, nbytes);
111}
112
113static int hmac_final(struct shash_desc *pdesc, u8 *out)
114{
115	struct crypto_shash *parent = pdesc->tfm;
116	int ds = crypto_shash_digestsize(parent);
117	int ss = crypto_shash_statesize(parent);
118	char *opad = crypto_shash_ctx_aligned(parent) + ss;
119	struct shash_desc *desc = shash_desc_ctx(pdesc);
120
121	return crypto_shash_final(desc, out) ?:
122	       crypto_shash_import(desc, opad) ?:
123	       crypto_shash_finup(desc, out, ds, out);
124}
125
126static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
127		      unsigned int nbytes, u8 *out)
128{
129
130	struct crypto_shash *parent = pdesc->tfm;
131	int ds = crypto_shash_digestsize(parent);
132	int ss = crypto_shash_statesize(parent);
133	char *opad = crypto_shash_ctx_aligned(parent) + ss;
134	struct shash_desc *desc = shash_desc_ctx(pdesc);
135
136	return crypto_shash_finup(desc, data, nbytes, out) ?:
137	       crypto_shash_import(desc, opad) ?:
138	       crypto_shash_finup(desc, out, ds, out);
139}
140
141static int hmac_init_tfm(struct crypto_shash *parent)
142{
 
143	struct crypto_shash *hash;
144	struct shash_instance *inst = shash_alg_instance(parent);
145	struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
146	struct hmac_ctx *ctx = hmac_ctx(parent);
147
148	hash = crypto_spawn_shash(spawn);
149	if (IS_ERR(hash))
150		return PTR_ERR(hash);
151
152	parent->descsize = sizeof(struct shash_desc) +
153			   crypto_shash_descsize(hash);
 
 
 
 
154
155	ctx->hash = hash;
156	return 0;
157}
158
159static void hmac_exit_tfm(struct crypto_shash *parent)
160{
161	struct hmac_ctx *ctx = hmac_ctx(parent);
162	crypto_free_shash(ctx->hash);
163}
164
165static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
166{
167	struct shash_instance *inst;
168	struct crypto_shash_spawn *spawn;
169	struct crypto_alg *alg;
170	struct shash_alg *salg;
171	u32 mask;
172	int err;
173	int ds;
174	int ss;
175
176	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);
177	if (err)
178		return err;
179
180	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
181	if (!inst)
182		return -ENOMEM;
183	spawn = shash_instance_ctx(inst);
184
185	err = crypto_grab_shash(spawn, shash_crypto_instance(inst),
186				crypto_attr_alg_name(tb[1]), 0, mask);
187	if (err)
188		goto err_free_inst;
189	salg = crypto_spawn_shash_alg(spawn);
190	alg = &salg->base;
191
192	/* The underlying hash algorithm must not require a key */
193	err = -EINVAL;
194	if (crypto_shash_alg_needs_key(salg))
195		goto err_free_inst;
196
197	ds = salg->digestsize;
198	ss = salg->statesize;
199	if (ds > alg->cra_blocksize ||
200	    ss < alg->cra_blocksize)
201		goto err_free_inst;
202
203	err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
 
 
 
 
 
 
204	if (err)
205		goto err_free_inst;
206
207	inst->alg.base.cra_priority = alg->cra_priority;
208	inst->alg.base.cra_blocksize = alg->cra_blocksize;
209	inst->alg.base.cra_alignmask = alg->cra_alignmask;
210
211	ss = ALIGN(ss, alg->cra_alignmask + 1);
212	inst->alg.digestsize = ds;
213	inst->alg.statesize = ss;
214
215	inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
216				     ALIGN(ss * 2, crypto_tfm_ctx_alignment());
217
 
 
 
218	inst->alg.init = hmac_init;
219	inst->alg.update = hmac_update;
220	inst->alg.final = hmac_final;
221	inst->alg.finup = hmac_finup;
222	inst->alg.export = hmac_export;
223	inst->alg.import = hmac_import;
224	inst->alg.setkey = hmac_setkey;
225	inst->alg.init_tfm = hmac_init_tfm;
226	inst->alg.exit_tfm = hmac_exit_tfm;
227
228	inst->free = shash_free_singlespawn_instance;
229
230	err = shash_register_instance(tmpl, inst);
231	if (err) {
232err_free_inst:
233		shash_free_singlespawn_instance(inst);
234	}
 
 
 
235	return err;
236}
237
238static struct crypto_template hmac_tmpl = {
239	.name = "hmac",
240	.create = hmac_create,
 
241	.module = THIS_MODULE,
242};
243
244static int __init hmac_module_init(void)
245{
246	return crypto_register_template(&hmac_tmpl);
247}
248
249static void __exit hmac_module_exit(void)
250{
251	crypto_unregister_template(&hmac_tmpl);
252}
253
254subsys_initcall(hmac_module_init);
255module_exit(hmac_module_exit);
256
257MODULE_LICENSE("GPL");
258MODULE_DESCRIPTION("HMAC hash algorithm");
259MODULE_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/init.h>
 19#include <linux/kernel.h>
 20#include <linux/module.h>
 21#include <linux/scatterlist.h>
 22#include <linux/string.h>
 23
 24struct hmac_ctx {
 25	struct crypto_shash *hash;
 26};
 27
 28static inline void *align_ptr(void *p, unsigned int align)
 29{
 30	return (void *)ALIGN((unsigned long)p, align);
 31}
 32
 33static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
 34{
 35	return align_ptr(crypto_shash_ctx_aligned(tfm) +
 36			 crypto_shash_statesize(tfm) * 2,
 37			 crypto_tfm_ctx_alignment());
 38}
 39
 40static int hmac_setkey(struct crypto_shash *parent,
 41		       const u8 *inkey, unsigned int keylen)
 42{
 43	int bs = crypto_shash_blocksize(parent);
 44	int ds = crypto_shash_digestsize(parent);
 45	int ss = crypto_shash_statesize(parent);
 46	char *ipad = crypto_shash_ctx_aligned(parent);
 47	char *opad = ipad + ss;
 48	struct hmac_ctx *ctx = align_ptr(opad + ss,
 49					 crypto_tfm_ctx_alignment());
 50	struct crypto_shash *hash = ctx->hash;
 51	SHASH_DESC_ON_STACK(shash, hash);
 52	unsigned int i;
 53
 54	shash->tfm = hash;
 55
 56	if (keylen > bs) {
 57		int err;
 58
 59		err = crypto_shash_digest(shash, inkey, keylen, ipad);
 60		if (err)
 61			return err;
 62
 63		keylen = ds;
 64	} else
 65		memcpy(ipad, inkey, keylen);
 66
 67	memset(ipad + keylen, 0, bs - keylen);
 68	memcpy(opad, ipad, bs);
 69
 70	for (i = 0; i < bs; i++) {
 71		ipad[i] ^= HMAC_IPAD_VALUE;
 72		opad[i] ^= HMAC_OPAD_VALUE;
 73	}
 74
 75	return crypto_shash_init(shash) ?:
 76	       crypto_shash_update(shash, ipad, bs) ?:
 77	       crypto_shash_export(shash, ipad) ?:
 78	       crypto_shash_init(shash) ?:
 79	       crypto_shash_update(shash, opad, bs) ?:
 80	       crypto_shash_export(shash, opad);
 81}
 82
 83static int hmac_export(struct shash_desc *pdesc, void *out)
 84{
 85	struct shash_desc *desc = shash_desc_ctx(pdesc);
 86
 87	return crypto_shash_export(desc, out);
 88}
 89
 90static int hmac_import(struct shash_desc *pdesc, const void *in)
 91{
 92	struct shash_desc *desc = shash_desc_ctx(pdesc);
 93	struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
 94
 95	desc->tfm = ctx->hash;
 96
 97	return crypto_shash_import(desc, in);
 98}
 99
100static int hmac_init(struct shash_desc *pdesc)
101{
102	return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
103}
104
105static int hmac_update(struct shash_desc *pdesc,
106		       const u8 *data, unsigned int nbytes)
107{
108	struct shash_desc *desc = shash_desc_ctx(pdesc);
109
110	return crypto_shash_update(desc, data, nbytes);
111}
112
113static int hmac_final(struct shash_desc *pdesc, u8 *out)
114{
115	struct crypto_shash *parent = pdesc->tfm;
116	int ds = crypto_shash_digestsize(parent);
117	int ss = crypto_shash_statesize(parent);
118	char *opad = crypto_shash_ctx_aligned(parent) + ss;
119	struct shash_desc *desc = shash_desc_ctx(pdesc);
120
121	return crypto_shash_final(desc, out) ?:
122	       crypto_shash_import(desc, opad) ?:
123	       crypto_shash_finup(desc, out, ds, out);
124}
125
126static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
127		      unsigned int nbytes, u8 *out)
128{
129
130	struct crypto_shash *parent = pdesc->tfm;
131	int ds = crypto_shash_digestsize(parent);
132	int ss = crypto_shash_statesize(parent);
133	char *opad = crypto_shash_ctx_aligned(parent) + ss;
134	struct shash_desc *desc = shash_desc_ctx(pdesc);
135
136	return crypto_shash_finup(desc, data, nbytes, out) ?:
137	       crypto_shash_import(desc, opad) ?:
138	       crypto_shash_finup(desc, out, ds, out);
139}
140
141static int hmac_init_tfm(struct crypto_tfm *tfm)
142{
143	struct crypto_shash *parent = __crypto_shash_cast(tfm);
144	struct crypto_shash *hash;
145	struct crypto_instance *inst = (void *)tfm->__crt_alg;
146	struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
147	struct hmac_ctx *ctx = hmac_ctx(parent);
148
149	hash = crypto_spawn_shash(spawn);
150	if (IS_ERR(hash))
151		return PTR_ERR(hash);
152
153	parent->descsize = sizeof(struct shash_desc) +
154			   crypto_shash_descsize(hash);
155	if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE)) {
156		crypto_free_shash(hash);
157		return -EINVAL;
158	}
159
160	ctx->hash = hash;
161	return 0;
162}
163
164static void hmac_exit_tfm(struct crypto_tfm *tfm)
165{
166	struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
167	crypto_free_shash(ctx->hash);
168}
169
170static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
171{
172	struct shash_instance *inst;
 
173	struct crypto_alg *alg;
174	struct shash_alg *salg;
 
175	int err;
176	int ds;
177	int ss;
178
179	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
180	if (err)
181		return err;
182
183	salg = shash_attr_alg(tb[1], 0, 0);
184	if (IS_ERR(salg))
185		return PTR_ERR(salg);
 
 
 
 
 
 
 
186	alg = &salg->base;
187
188	/* The underlying hash algorithm must be unkeyed */
189	err = -EINVAL;
190	if (crypto_shash_alg_has_setkey(salg))
191		goto out_put_alg;
192
193	ds = salg->digestsize;
194	ss = salg->statesize;
195	if (ds > alg->cra_blocksize ||
196	    ss < alg->cra_blocksize)
197		goto out_put_alg;
198
199	inst = shash_alloc_instance("hmac", alg);
200	err = PTR_ERR(inst);
201	if (IS_ERR(inst))
202		goto out_put_alg;
203
204	err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
205				      shash_crypto_instance(inst));
206	if (err)
207		goto out_free_inst;
208
209	inst->alg.base.cra_priority = alg->cra_priority;
210	inst->alg.base.cra_blocksize = alg->cra_blocksize;
211	inst->alg.base.cra_alignmask = alg->cra_alignmask;
212
213	ss = ALIGN(ss, alg->cra_alignmask + 1);
214	inst->alg.digestsize = ds;
215	inst->alg.statesize = ss;
216
217	inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
218				     ALIGN(ss * 2, crypto_tfm_ctx_alignment());
219
220	inst->alg.base.cra_init = hmac_init_tfm;
221	inst->alg.base.cra_exit = hmac_exit_tfm;
222
223	inst->alg.init = hmac_init;
224	inst->alg.update = hmac_update;
225	inst->alg.final = hmac_final;
226	inst->alg.finup = hmac_finup;
227	inst->alg.export = hmac_export;
228	inst->alg.import = hmac_import;
229	inst->alg.setkey = hmac_setkey;
 
 
 
 
230
231	err = shash_register_instance(tmpl, inst);
232	if (err) {
233out_free_inst:
234		shash_free_instance(shash_crypto_instance(inst));
235	}
236
237out_put_alg:
238	crypto_mod_put(alg);
239	return err;
240}
241
242static struct crypto_template hmac_tmpl = {
243	.name = "hmac",
244	.create = hmac_create,
245	.free = shash_free_instance,
246	.module = THIS_MODULE,
247};
248
249static int __init hmac_module_init(void)
250{
251	return crypto_register_template(&hmac_tmpl);
252}
253
254static void __exit hmac_module_exit(void)
255{
256	crypto_unregister_template(&hmac_tmpl);
257}
258
259subsys_initcall(hmac_module_init);
260module_exit(hmac_module_exit);
261
262MODULE_LICENSE("GPL");
263MODULE_DESCRIPTION("HMAC hash algorithm");
264MODULE_ALIAS_CRYPTO("hmac");