Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Cryptographic API. | |
4 | * | |
5 | * HMAC: Keyed-Hashing for Message Authentication (RFC2104). | |
6 | * | |
7 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> | |
0796ae06 | 8 | * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> |
1da177e4 LT |
9 | * |
10 | * The HMAC implementation is derived from USAGI. | |
11 | * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI | |
1da177e4 | 12 | */ |
0796ae06 | 13 | |
03d7db56 | 14 | #include <crypto/hmac.h> |
5f7082ed | 15 | #include <crypto/internal/hash.h> |
b2ab4a57 | 16 | #include <crypto/scatterwalk.h> |
0796ae06 | 17 | #include <linux/err.h> |
37f36e57 | 18 | #include <linux/fips.h> |
0796ae06 HX |
19 | #include <linux/init.h> |
20 | #include <linux/kernel.h> | |
21 | #include <linux/module.h> | |
378f058c | 22 | #include <linux/scatterlist.h> |
0796ae06 HX |
23 | #include <linux/string.h> |
24 | ||
25 | struct hmac_ctx { | |
0b767b4d | 26 | struct crypto_shash *hash; |
0796ae06 | 27 | }; |
1da177e4 | 28 | |
0796ae06 HX |
29 | static inline void *align_ptr(void *p, unsigned int align) |
30 | { | |
31 | return (void *)ALIGN((unsigned long)p, align); | |
32 | } | |
33 | ||
8bd1209c | 34 | static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm) |
0796ae06 | 35 | { |
8bd1209c | 36 | return align_ptr(crypto_shash_ctx_aligned(tfm) + |
0b767b4d | 37 | crypto_shash_statesize(tfm) * 2, |
8bd1209c | 38 | crypto_tfm_ctx_alignment()); |
0796ae06 HX |
39 | } |
40 | ||
8bd1209c | 41 | static int hmac_setkey(struct crypto_shash *parent, |
0796ae06 HX |
42 | const u8 *inkey, unsigned int keylen) |
43 | { | |
8bd1209c HX |
44 | int bs = crypto_shash_blocksize(parent); |
45 | int ds = crypto_shash_digestsize(parent); | |
0b767b4d | 46 | int ss = crypto_shash_statesize(parent); |
8bd1209c | 47 | char *ipad = crypto_shash_ctx_aligned(parent); |
0b767b4d HX |
48 | char *opad = ipad + ss; |
49 | struct hmac_ctx *ctx = align_ptr(opad + ss, | |
8bd1209c | 50 | crypto_tfm_ctx_alignment()); |
0b767b4d | 51 | struct crypto_shash *hash = ctx->hash; |
ffb32e97 | 52 | SHASH_DESC_ON_STACK(shash, hash); |
0796ae06 HX |
53 | unsigned int i; |
54 | ||
37f36e57 SM |
55 | if (fips_enabled && (keylen < 112 / 8)) |
56 | return -EINVAL; | |
57 | ||
ffb32e97 | 58 | shash->tfm = hash; |
0b767b4d | 59 | |
0796ae06 | 60 | if (keylen > bs) { |
0796ae06 HX |
61 | int err; |
62 | ||
ffb32e97 | 63 | err = crypto_shash_digest(shash, inkey, keylen, ipad); |
0796ae06 HX |
64 | if (err) |
65 | return err; | |
66 | ||
0796ae06 | 67 | keylen = ds; |
0b767b4d HX |
68 | } else |
69 | memcpy(ipad, inkey, keylen); | |
0796ae06 | 70 | |
0796ae06 HX |
71 | memset(ipad + keylen, 0, bs - keylen); |
72 | memcpy(opad, ipad, bs); | |
73 | ||
74 | for (i = 0; i < bs; i++) { | |
03d7db56 CL |
75 | ipad[i] ^= HMAC_IPAD_VALUE; |
76 | opad[i] ^= HMAC_OPAD_VALUE; | |
0796ae06 HX |
77 | } |
78 | ||
ffb32e97 JSM |
79 | return crypto_shash_init(shash) ?: |
80 | crypto_shash_update(shash, ipad, bs) ?: | |
81 | crypto_shash_export(shash, ipad) ?: | |
82 | crypto_shash_init(shash) ?: | |
83 | crypto_shash_update(shash, opad, bs) ?: | |
84 | crypto_shash_export(shash, opad); | |
0796ae06 HX |
85 | } |
86 | ||
0b767b4d HX |
87 | static int hmac_export(struct shash_desc *pdesc, void *out) |
88 | { | |
89 | struct shash_desc *desc = shash_desc_ctx(pdesc); | |
90 | ||
0b767b4d HX |
91 | return crypto_shash_export(desc, out); |
92 | } | |
93 | ||
94 | static int hmac_import(struct shash_desc *pdesc, const void *in) | |
0796ae06 | 95 | { |
8bd1209c | 96 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0b767b4d | 97 | struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm); |
8bd1209c | 98 | |
0b767b4d | 99 | desc->tfm = ctx->hash; |
8bd1209c | 100 | |
0b767b4d HX |
101 | return crypto_shash_import(desc, in); |
102 | } | |
103 | ||
104 | static int hmac_init(struct shash_desc *pdesc) | |
105 | { | |
106 | return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm)); | |
0796ae06 HX |
107 | } |
108 | ||
8bd1209c HX |
109 | static int hmac_update(struct shash_desc *pdesc, |
110 | const u8 *data, unsigned int nbytes) | |
0796ae06 | 111 | { |
8bd1209c | 112 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 113 | |
8bd1209c | 114 | return crypto_shash_update(desc, data, nbytes); |
0796ae06 HX |
115 | } |
116 | ||
8bd1209c | 117 | static int hmac_final(struct shash_desc *pdesc, u8 *out) |
0796ae06 | 118 | { |
8bd1209c | 119 | struct crypto_shash *parent = pdesc->tfm; |
8bd1209c | 120 | int ds = crypto_shash_digestsize(parent); |
0b767b4d HX |
121 | int ss = crypto_shash_statesize(parent); |
122 | char *opad = crypto_shash_ctx_aligned(parent) + ss; | |
8bd1209c | 123 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 124 | |
0b767b4d HX |
125 | return crypto_shash_final(desc, out) ?: |
126 | crypto_shash_import(desc, opad) ?: | |
127 | crypto_shash_finup(desc, out, ds, out); | |
0796ae06 HX |
128 | } |
129 | ||
8bd1209c HX |
130 | static int hmac_finup(struct shash_desc *pdesc, const u8 *data, |
131 | unsigned int nbytes, u8 *out) | |
0796ae06 | 132 | { |
0796ae06 | 133 | |
8bd1209c | 134 | struct crypto_shash *parent = pdesc->tfm; |
8bd1209c | 135 | int ds = crypto_shash_digestsize(parent); |
0b767b4d HX |
136 | int ss = crypto_shash_statesize(parent); |
137 | char *opad = crypto_shash_ctx_aligned(parent) + ss; | |
8bd1209c | 138 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
78c2f0b8 | 139 | |
0b767b4d HX |
140 | return crypto_shash_finup(desc, data, nbytes, out) ?: |
141 | crypto_shash_import(desc, opad) ?: | |
142 | crypto_shash_finup(desc, out, ds, out); | |
0796ae06 HX |
143 | } |
144 | ||
d9e1670b | 145 | static int hmac_init_tfm(struct crypto_shash *parent) |
0796ae06 | 146 | { |
8bd1209c | 147 | struct crypto_shash *hash; |
d9e1670b HX |
148 | struct shash_instance *inst = shash_alg_instance(parent); |
149 | struct crypto_shash_spawn *spawn = shash_instance_ctx(inst); | |
8bd1209c | 150 | struct hmac_ctx *ctx = hmac_ctx(parent); |
0796ae06 | 151 | |
8bd1209c | 152 | hash = crypto_spawn_shash(spawn); |
2e306ee0 HX |
153 | if (IS_ERR(hash)) |
154 | return PTR_ERR(hash); | |
0796ae06 | 155 | |
8bd1209c HX |
156 | parent->descsize = sizeof(struct shash_desc) + |
157 | crypto_shash_descsize(hash); | |
158 | ||
0b767b4d | 159 | ctx->hash = hash; |
0796ae06 HX |
160 | return 0; |
161 | } | |
162 | ||
d9e1670b | 163 | static void hmac_exit_tfm(struct crypto_shash *parent) |
0796ae06 | 164 | { |
d9e1670b | 165 | struct hmac_ctx *ctx = hmac_ctx(parent); |
0b767b4d | 166 | crypto_free_shash(ctx->hash); |
0796ae06 HX |
167 | } |
168 | ||
8bd1209c | 169 | static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb) |
0796ae06 | 170 | { |
8bd1209c | 171 | struct shash_instance *inst; |
39e7a283 | 172 | struct crypto_shash_spawn *spawn; |
0796ae06 | 173 | struct crypto_alg *alg; |
8bd1209c | 174 | struct shash_alg *salg; |
7bcb2c99 | 175 | u32 mask; |
ebc610e5 | 176 | int err; |
ca786dc7 | 177 | int ds; |
0b767b4d | 178 | int ss; |
ebc610e5 | 179 | |
7bcb2c99 | 180 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask); |
ebc610e5 | 181 | if (err) |
8bd1209c HX |
182 | return err; |
183 | ||
39e7a283 EB |
184 | inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); |
185 | if (!inst) | |
186 | return -ENOMEM; | |
187 | spawn = shash_instance_ctx(inst); | |
188 | ||
189 | err = crypto_grab_shash(spawn, shash_crypto_instance(inst), | |
7bcb2c99 | 190 | crypto_attr_alg_name(tb[1]), 0, mask); |
39e7a283 EB |
191 | if (err) |
192 | goto err_free_inst; | |
193 | salg = crypto_spawn_shash_alg(spawn); | |
af3ff804 | 194 | alg = &salg->base; |
8bd1209c | 195 | |
c2881789 | 196 | /* The underlying hash algorithm must not require a key */ |
8bd1209c | 197 | err = -EINVAL; |
c2881789 | 198 | if (crypto_shash_alg_needs_key(salg)) |
39e7a283 | 199 | goto err_free_inst; |
af3ff804 | 200 | |
8bd1209c | 201 | ds = salg->digestsize; |
0b767b4d | 202 | ss = salg->statesize; |
0b767b4d HX |
203 | if (ds > alg->cra_blocksize || |
204 | ss < alg->cra_blocksize) | |
39e7a283 | 205 | goto err_free_inst; |
ca786dc7 | 206 | |
39e7a283 | 207 | err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg); |
8bd1209c | 208 | if (err) |
39e7a283 | 209 | goto err_free_inst; |
8bd1209c HX |
210 | |
211 | inst->alg.base.cra_priority = alg->cra_priority; | |
212 | inst->alg.base.cra_blocksize = alg->cra_blocksize; | |
213 | inst->alg.base.cra_alignmask = alg->cra_alignmask; | |
0796ae06 | 214 | |
0b767b4d | 215 | ss = ALIGN(ss, alg->cra_alignmask + 1); |
8bd1209c | 216 | inst->alg.digestsize = ds; |
0b767b4d | 217 | inst->alg.statesize = ss; |
0796ae06 | 218 | |
8bd1209c | 219 | inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) + |
0b767b4d | 220 | ALIGN(ss * 2, crypto_tfm_ctx_alignment()); |
0796ae06 | 221 | |
8bd1209c HX |
222 | inst->alg.init = hmac_init; |
223 | inst->alg.update = hmac_update; | |
224 | inst->alg.final = hmac_final; | |
225 | inst->alg.finup = hmac_finup; | |
0b767b4d HX |
226 | inst->alg.export = hmac_export; |
227 | inst->alg.import = hmac_import; | |
8bd1209c | 228 | inst->alg.setkey = hmac_setkey; |
d9e1670b HX |
229 | inst->alg.init_tfm = hmac_init_tfm; |
230 | inst->alg.exit_tfm = hmac_exit_tfm; | |
8bd1209c | 231 | |
a39c66cc EB |
232 | inst->free = shash_free_singlespawn_instance; |
233 | ||
8bd1209c HX |
234 | err = shash_register_instance(tmpl, inst); |
235 | if (err) { | |
39e7a283 | 236 | err_free_inst: |
a39c66cc | 237 | shash_free_singlespawn_instance(inst); |
8bd1209c | 238 | } |
8bd1209c | 239 | return err; |
0796ae06 HX |
240 | } |
241 | ||
242 | static struct crypto_template hmac_tmpl = { | |
243 | .name = "hmac", | |
8bd1209c | 244 | .create = hmac_create, |
0796ae06 HX |
245 | .module = THIS_MODULE, |
246 | }; | |
247 | ||
248 | static int __init hmac_module_init(void) | |
249 | { | |
250 | return crypto_register_template(&hmac_tmpl); | |
251 | } | |
252 | ||
253 | static void __exit hmac_module_exit(void) | |
254 | { | |
255 | crypto_unregister_template(&hmac_tmpl); | |
256 | } | |
257 | ||
c4741b23 | 258 | subsys_initcall(hmac_module_init); |
0796ae06 HX |
259 | module_exit(hmac_module_exit); |
260 | ||
261 | MODULE_LICENSE("GPL"); | |
262 | MODULE_DESCRIPTION("HMAC hash algorithm"); | |
4943ba16 | 263 | MODULE_ALIAS_CRYPTO("hmac"); |