Loading...
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/hmac.h>
20#include <crypto/internal/hash.h>
21#include <crypto/scatterwalk.h>
22#include <linux/err.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/scatterlist.h>
27#include <linux/string.h>
28
29struct hmac_ctx {
30 struct crypto_shash *hash;
31};
32
33static inline void *align_ptr(void *p, unsigned int align)
34{
35 return (void *)ALIGN((unsigned long)p, align);
36}
37
38static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
39{
40 return align_ptr(crypto_shash_ctx_aligned(tfm) +
41 crypto_shash_statesize(tfm) * 2,
42 crypto_tfm_ctx_alignment());
43}
44
45static int hmac_setkey(struct crypto_shash *parent,
46 const u8 *inkey, unsigned int keylen)
47{
48 int bs = crypto_shash_blocksize(parent);
49 int ds = crypto_shash_digestsize(parent);
50 int ss = crypto_shash_statesize(parent);
51 char *ipad = crypto_shash_ctx_aligned(parent);
52 char *opad = ipad + ss;
53 struct hmac_ctx *ctx = align_ptr(opad + ss,
54 crypto_tfm_ctx_alignment());
55 struct crypto_shash *hash = ctx->hash;
56 SHASH_DESC_ON_STACK(shash, hash);
57 unsigned int i;
58
59 shash->tfm = hash;
60 shash->flags = crypto_shash_get_flags(parent)
61 & CRYPTO_TFM_REQ_MAY_SLEEP;
62
63 if (keylen > bs) {
64 int err;
65
66 err = crypto_shash_digest(shash, inkey, keylen, ipad);
67 if (err)
68 return err;
69
70 keylen = ds;
71 } else
72 memcpy(ipad, inkey, keylen);
73
74 memset(ipad + keylen, 0, bs - keylen);
75 memcpy(opad, ipad, bs);
76
77 for (i = 0; i < bs; i++) {
78 ipad[i] ^= HMAC_IPAD_VALUE;
79 opad[i] ^= HMAC_OPAD_VALUE;
80 }
81
82 return crypto_shash_init(shash) ?:
83 crypto_shash_update(shash, ipad, bs) ?:
84 crypto_shash_export(shash, ipad) ?:
85 crypto_shash_init(shash) ?:
86 crypto_shash_update(shash, opad, bs) ?:
87 crypto_shash_export(shash, opad);
88}
89
90static int hmac_export(struct shash_desc *pdesc, void *out)
91{
92 struct shash_desc *desc = shash_desc_ctx(pdesc);
93
94 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
95
96 return crypto_shash_export(desc, out);
97}
98
99static int hmac_import(struct shash_desc *pdesc, const void *in)
100{
101 struct shash_desc *desc = shash_desc_ctx(pdesc);
102 struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
103
104 desc->tfm = ctx->hash;
105 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
106
107 return crypto_shash_import(desc, in);
108}
109
110static int hmac_init(struct shash_desc *pdesc)
111{
112 return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
113}
114
115static int hmac_update(struct shash_desc *pdesc,
116 const u8 *data, unsigned int nbytes)
117{
118 struct shash_desc *desc = shash_desc_ctx(pdesc);
119
120 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
121
122 return crypto_shash_update(desc, data, nbytes);
123}
124
125static int hmac_final(struct shash_desc *pdesc, u8 *out)
126{
127 struct crypto_shash *parent = pdesc->tfm;
128 int ds = crypto_shash_digestsize(parent);
129 int ss = crypto_shash_statesize(parent);
130 char *opad = crypto_shash_ctx_aligned(parent) + ss;
131 struct shash_desc *desc = shash_desc_ctx(pdesc);
132
133 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
134
135 return crypto_shash_final(desc, out) ?:
136 crypto_shash_import(desc, opad) ?:
137 crypto_shash_finup(desc, out, ds, out);
138}
139
140static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
141 unsigned int nbytes, u8 *out)
142{
143
144 struct crypto_shash *parent = pdesc->tfm;
145 int ds = crypto_shash_digestsize(parent);
146 int ss = crypto_shash_statesize(parent);
147 char *opad = crypto_shash_ctx_aligned(parent) + ss;
148 struct shash_desc *desc = shash_desc_ctx(pdesc);
149
150 desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
151
152 return crypto_shash_finup(desc, data, nbytes, out) ?:
153 crypto_shash_import(desc, opad) ?:
154 crypto_shash_finup(desc, out, ds, out);
155}
156
157static int hmac_init_tfm(struct crypto_tfm *tfm)
158{
159 struct crypto_shash *parent = __crypto_shash_cast(tfm);
160 struct crypto_shash *hash;
161 struct crypto_instance *inst = (void *)tfm->__crt_alg;
162 struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
163 struct hmac_ctx *ctx = hmac_ctx(parent);
164
165 hash = crypto_spawn_shash(spawn);
166 if (IS_ERR(hash))
167 return PTR_ERR(hash);
168
169 parent->descsize = sizeof(struct shash_desc) +
170 crypto_shash_descsize(hash);
171
172 ctx->hash = hash;
173 return 0;
174}
175
176static void hmac_exit_tfm(struct crypto_tfm *tfm)
177{
178 struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
179 crypto_free_shash(ctx->hash);
180}
181
182static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
183{
184 struct shash_instance *inst;
185 struct crypto_alg *alg;
186 struct shash_alg *salg;
187 int err;
188 int ds;
189 int ss;
190
191 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
192 if (err)
193 return err;
194
195 salg = shash_attr_alg(tb[1], 0, 0);
196 if (IS_ERR(salg))
197 return PTR_ERR(salg);
198 alg = &salg->base;
199
200 /* The underlying hash algorithm must be unkeyed */
201 err = -EINVAL;
202 if (crypto_shash_alg_has_setkey(salg))
203 goto out_put_alg;
204
205 ds = salg->digestsize;
206 ss = salg->statesize;
207 if (ds > alg->cra_blocksize ||
208 ss < alg->cra_blocksize)
209 goto out_put_alg;
210
211 inst = shash_alloc_instance("hmac", alg);
212 err = PTR_ERR(inst);
213 if (IS_ERR(inst))
214 goto out_put_alg;
215
216 err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
217 shash_crypto_instance(inst));
218 if (err)
219 goto out_free_inst;
220
221 inst->alg.base.cra_priority = alg->cra_priority;
222 inst->alg.base.cra_blocksize = alg->cra_blocksize;
223 inst->alg.base.cra_alignmask = alg->cra_alignmask;
224
225 ss = ALIGN(ss, alg->cra_alignmask + 1);
226 inst->alg.digestsize = ds;
227 inst->alg.statesize = ss;
228
229 inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
230 ALIGN(ss * 2, crypto_tfm_ctx_alignment());
231
232 inst->alg.base.cra_init = hmac_init_tfm;
233 inst->alg.base.cra_exit = hmac_exit_tfm;
234
235 inst->alg.init = hmac_init;
236 inst->alg.update = hmac_update;
237 inst->alg.final = hmac_final;
238 inst->alg.finup = hmac_finup;
239 inst->alg.export = hmac_export;
240 inst->alg.import = hmac_import;
241 inst->alg.setkey = hmac_setkey;
242
243 err = shash_register_instance(tmpl, inst);
244 if (err) {
245out_free_inst:
246 shash_free_instance(shash_crypto_instance(inst));
247 }
248
249out_put_alg:
250 crypto_mod_put(alg);
251 return err;
252}
253
254static struct crypto_template hmac_tmpl = {
255 .name = "hmac",
256 .create = hmac_create,
257 .free = shash_free_instance,
258 .module = THIS_MODULE,
259};
260
261static int __init hmac_module_init(void)
262{
263 return crypto_register_template(&hmac_tmpl);
264}
265
266static void __exit hmac_module_exit(void)
267{
268 crypto_unregister_template(&hmac_tmpl);
269}
270
271module_init(hmac_module_init);
272module_exit(hmac_module_exit);
273
274MODULE_LICENSE("GPL");
275MODULE_DESCRIPTION("HMAC hash algorithm");
276MODULE_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_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");