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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
4 | * HMAC: Keyed-Hashing for Message Authentication (RFC2104). | |
5 | * | |
6 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> | |
0796ae06 | 7 | * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> |
1da177e4 LT |
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 | |
0796ae06 | 14 | * Software Foundation; either version 2 of the License, or (at your option) |
1da177e4 LT |
15 | * any later version. |
16 | * | |
17 | */ | |
0796ae06 | 18 | |
03d7db56 | 19 | #include <crypto/hmac.h> |
5f7082ed | 20 | #include <crypto/internal/hash.h> |
b2ab4a57 | 21 | #include <crypto/scatterwalk.h> |
0796ae06 HX |
22 | #include <linux/err.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
378f058c | 26 | #include <linux/scatterlist.h> |
0796ae06 HX |
27 | #include <linux/string.h> |
28 | ||
29 | struct hmac_ctx { | |
0b767b4d | 30 | struct crypto_shash *hash; |
0796ae06 | 31 | }; |
1da177e4 | 32 | |
0796ae06 HX |
33 | static inline void *align_ptr(void *p, unsigned int align) |
34 | { | |
35 | return (void *)ALIGN((unsigned long)p, align); | |
36 | } | |
37 | ||
8bd1209c | 38 | static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm) |
0796ae06 | 39 | { |
8bd1209c | 40 | return align_ptr(crypto_shash_ctx_aligned(tfm) + |
0b767b4d | 41 | crypto_shash_statesize(tfm) * 2, |
8bd1209c | 42 | crypto_tfm_ctx_alignment()); |
0796ae06 HX |
43 | } |
44 | ||
8bd1209c | 45 | static int hmac_setkey(struct crypto_shash *parent, |
0796ae06 HX |
46 | const u8 *inkey, unsigned int keylen) |
47 | { | |
8bd1209c HX |
48 | int bs = crypto_shash_blocksize(parent); |
49 | int ds = crypto_shash_digestsize(parent); | |
0b767b4d | 50 | int ss = crypto_shash_statesize(parent); |
8bd1209c | 51 | char *ipad = crypto_shash_ctx_aligned(parent); |
0b767b4d HX |
52 | char *opad = ipad + ss; |
53 | struct hmac_ctx *ctx = align_ptr(opad + ss, | |
8bd1209c | 54 | crypto_tfm_ctx_alignment()); |
0b767b4d | 55 | struct crypto_shash *hash = ctx->hash; |
ffb32e97 | 56 | SHASH_DESC_ON_STACK(shash, hash); |
0796ae06 HX |
57 | unsigned int i; |
58 | ||
ffb32e97 | 59 | shash->tfm = hash; |
0b767b4d | 60 | |
0796ae06 | 61 | if (keylen > bs) { |
0796ae06 HX |
62 | int err; |
63 | ||
ffb32e97 | 64 | err = crypto_shash_digest(shash, inkey, keylen, ipad); |
0796ae06 HX |
65 | if (err) |
66 | return err; | |
67 | ||
0796ae06 | 68 | keylen = ds; |
0b767b4d HX |
69 | } else |
70 | memcpy(ipad, inkey, keylen); | |
0796ae06 | 71 | |
0796ae06 HX |
72 | memset(ipad + keylen, 0, bs - keylen); |
73 | memcpy(opad, ipad, bs); | |
74 | ||
75 | for (i = 0; i < bs; i++) { | |
03d7db56 CL |
76 | ipad[i] ^= HMAC_IPAD_VALUE; |
77 | opad[i] ^= HMAC_OPAD_VALUE; | |
0796ae06 HX |
78 | } |
79 | ||
ffb32e97 JSM |
80 | return crypto_shash_init(shash) ?: |
81 | crypto_shash_update(shash, ipad, bs) ?: | |
82 | crypto_shash_export(shash, ipad) ?: | |
83 | crypto_shash_init(shash) ?: | |
84 | crypto_shash_update(shash, opad, bs) ?: | |
85 | crypto_shash_export(shash, opad); | |
0796ae06 HX |
86 | } |
87 | ||
0b767b4d HX |
88 | static int hmac_export(struct shash_desc *pdesc, void *out) |
89 | { | |
90 | struct shash_desc *desc = shash_desc_ctx(pdesc); | |
91 | ||
0b767b4d HX |
92 | return crypto_shash_export(desc, out); |
93 | } | |
94 | ||
95 | static int hmac_import(struct shash_desc *pdesc, const void *in) | |
0796ae06 | 96 | { |
8bd1209c | 97 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0b767b4d | 98 | struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm); |
8bd1209c | 99 | |
0b767b4d | 100 | desc->tfm = ctx->hash; |
8bd1209c | 101 | |
0b767b4d HX |
102 | return crypto_shash_import(desc, in); |
103 | } | |
104 | ||
105 | static int hmac_init(struct shash_desc *pdesc) | |
106 | { | |
107 | return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm)); | |
0796ae06 HX |
108 | } |
109 | ||
8bd1209c HX |
110 | static int hmac_update(struct shash_desc *pdesc, |
111 | const u8 *data, unsigned int nbytes) | |
0796ae06 | 112 | { |
8bd1209c | 113 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 114 | |
8bd1209c | 115 | return crypto_shash_update(desc, data, nbytes); |
0796ae06 HX |
116 | } |
117 | ||
8bd1209c | 118 | static int hmac_final(struct shash_desc *pdesc, u8 *out) |
0796ae06 | 119 | { |
8bd1209c | 120 | struct crypto_shash *parent = pdesc->tfm; |
8bd1209c | 121 | int ds = crypto_shash_digestsize(parent); |
0b767b4d HX |
122 | int ss = crypto_shash_statesize(parent); |
123 | char *opad = crypto_shash_ctx_aligned(parent) + ss; | |
8bd1209c | 124 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 125 | |
0b767b4d HX |
126 | return crypto_shash_final(desc, out) ?: |
127 | crypto_shash_import(desc, opad) ?: | |
128 | crypto_shash_finup(desc, out, ds, out); | |
0796ae06 HX |
129 | } |
130 | ||
8bd1209c HX |
131 | static int hmac_finup(struct shash_desc *pdesc, const u8 *data, |
132 | unsigned int nbytes, u8 *out) | |
0796ae06 | 133 | { |
0796ae06 | 134 | |
8bd1209c | 135 | struct crypto_shash *parent = pdesc->tfm; |
8bd1209c | 136 | int ds = crypto_shash_digestsize(parent); |
0b767b4d HX |
137 | int ss = crypto_shash_statesize(parent); |
138 | char *opad = crypto_shash_ctx_aligned(parent) + ss; | |
8bd1209c | 139 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
78c2f0b8 | 140 | |
0b767b4d HX |
141 | return crypto_shash_finup(desc, data, nbytes, out) ?: |
142 | crypto_shash_import(desc, opad) ?: | |
143 | crypto_shash_finup(desc, out, ds, out); | |
0796ae06 HX |
144 | } |
145 | ||
146 | static int hmac_init_tfm(struct crypto_tfm *tfm) | |
147 | { | |
8bd1209c HX |
148 | struct crypto_shash *parent = __crypto_shash_cast(tfm); |
149 | struct crypto_shash *hash; | |
0796ae06 | 150 | struct crypto_instance *inst = (void *)tfm->__crt_alg; |
8bd1209c HX |
151 | struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst); |
152 | struct hmac_ctx *ctx = hmac_ctx(parent); | |
0796ae06 | 153 | |
8bd1209c | 154 | hash = crypto_spawn_shash(spawn); |
2e306ee0 HX |
155 | if (IS_ERR(hash)) |
156 | return PTR_ERR(hash); | |
0796ae06 | 157 | |
8bd1209c HX |
158 | parent->descsize = sizeof(struct shash_desc) + |
159 | crypto_shash_descsize(hash); | |
160 | ||
0b767b4d | 161 | ctx->hash = hash; |
0796ae06 HX |
162 | return 0; |
163 | } | |
164 | ||
165 | static void hmac_exit_tfm(struct crypto_tfm *tfm) | |
166 | { | |
8bd1209c | 167 | struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm)); |
0b767b4d | 168 | crypto_free_shash(ctx->hash); |
0796ae06 HX |
169 | } |
170 | ||
8bd1209c | 171 | static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb) |
0796ae06 | 172 | { |
8bd1209c | 173 | struct shash_instance *inst; |
0796ae06 | 174 | struct crypto_alg *alg; |
8bd1209c | 175 | struct shash_alg *salg; |
ebc610e5 | 176 | int err; |
ca786dc7 | 177 | int ds; |
0b767b4d | 178 | int ss; |
ebc610e5 | 179 | |
8bd1209c | 180 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); |
ebc610e5 | 181 | if (err) |
8bd1209c HX |
182 | return err; |
183 | ||
184 | salg = shash_attr_alg(tb[1], 0, 0); | |
185 | if (IS_ERR(salg)) | |
186 | return PTR_ERR(salg); | |
af3ff804 | 187 | alg = &salg->base; |
8bd1209c | 188 | |
af3ff804 | 189 | /* The underlying hash algorithm must be unkeyed */ |
8bd1209c | 190 | err = -EINVAL; |
af3ff804 EB |
191 | if (crypto_shash_alg_has_setkey(salg)) |
192 | goto out_put_alg; | |
193 | ||
8bd1209c | 194 | ds = salg->digestsize; |
0b767b4d | 195 | ss = salg->statesize; |
0b767b4d HX |
196 | if (ds > alg->cra_blocksize || |
197 | ss < alg->cra_blocksize) | |
ca786dc7 HX |
198 | goto out_put_alg; |
199 | ||
8bd1209c | 200 | inst = shash_alloc_instance("hmac", alg); |
3b3fc322 | 201 | err = PTR_ERR(inst); |
0796ae06 HX |
202 | if (IS_ERR(inst)) |
203 | goto out_put_alg; | |
204 | ||
8bd1209c HX |
205 | err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg, |
206 | shash_crypto_instance(inst)); | |
207 | if (err) | |
208 | goto out_free_inst; | |
209 | ||
210 | inst->alg.base.cra_priority = alg->cra_priority; | |
211 | inst->alg.base.cra_blocksize = alg->cra_blocksize; | |
212 | inst->alg.base.cra_alignmask = alg->cra_alignmask; | |
0796ae06 | 213 | |
0b767b4d | 214 | ss = ALIGN(ss, alg->cra_alignmask + 1); |
8bd1209c | 215 | inst->alg.digestsize = ds; |
0b767b4d | 216 | inst->alg.statesize = ss; |
0796ae06 | 217 | |
8bd1209c | 218 | inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) + |
0b767b4d | 219 | ALIGN(ss * 2, crypto_tfm_ctx_alignment()); |
0796ae06 | 220 | |
8bd1209c HX |
221 | inst->alg.base.cra_init = hmac_init_tfm; |
222 | inst->alg.base.cra_exit = hmac_exit_tfm; | |
0796ae06 | 223 | |
8bd1209c HX |
224 | inst->alg.init = hmac_init; |
225 | inst->alg.update = hmac_update; | |
226 | inst->alg.final = hmac_final; | |
227 | inst->alg.finup = hmac_finup; | |
0b767b4d HX |
228 | inst->alg.export = hmac_export; |
229 | inst->alg.import = hmac_import; | |
8bd1209c HX |
230 | inst->alg.setkey = hmac_setkey; |
231 | ||
232 | err = shash_register_instance(tmpl, inst); | |
233 | if (err) { | |
234 | out_free_inst: | |
235 | shash_free_instance(shash_crypto_instance(inst)); | |
236 | } | |
0796ae06 HX |
237 | |
238 | out_put_alg: | |
239 | crypto_mod_put(alg); | |
8bd1209c | 240 | return err; |
0796ae06 HX |
241 | } |
242 | ||
243 | static struct crypto_template hmac_tmpl = { | |
244 | .name = "hmac", | |
8bd1209c HX |
245 | .create = hmac_create, |
246 | .free = shash_free_instance, | |
0796ae06 HX |
247 | .module = THIS_MODULE, |
248 | }; | |
249 | ||
250 | static int __init hmac_module_init(void) | |
251 | { | |
252 | return crypto_register_template(&hmac_tmpl); | |
253 | } | |
254 | ||
255 | static void __exit hmac_module_exit(void) | |
256 | { | |
257 | crypto_unregister_template(&hmac_tmpl); | |
258 | } | |
259 | ||
c4741b23 | 260 | subsys_initcall(hmac_module_init); |
0796ae06 HX |
261 | module_exit(hmac_module_exit); |
262 | ||
263 | MODULE_LICENSE("GPL"); | |
264 | MODULE_DESCRIPTION("HMAC hash algorithm"); | |
4943ba16 | 265 | MODULE_ALIAS_CRYPTO("hmac"); |