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 | |
5f7082ed | 19 | #include <crypto/internal/hash.h> |
b2ab4a57 | 20 | #include <crypto/scatterwalk.h> |
0796ae06 HX |
21 | #include <linux/err.h> |
22 | #include <linux/init.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/module.h> | |
378f058c | 25 | #include <linux/scatterlist.h> |
0796ae06 HX |
26 | #include <linux/slab.h> |
27 | #include <linux/string.h> | |
28 | ||
29 | struct hmac_ctx { | |
8bd1209c | 30 | struct shash_desc *desc; |
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 HX |
40 | return align_ptr(crypto_shash_ctx_aligned(tfm) + |
41 | crypto_shash_blocksize(tfm) * 2 + | |
42 | crypto_shash_digestsize(tfm), | |
43 | crypto_tfm_ctx_alignment()); | |
0796ae06 HX |
44 | } |
45 | ||
8bd1209c | 46 | static int hmac_setkey(struct crypto_shash *parent, |
0796ae06 HX |
47 | const u8 *inkey, unsigned int keylen) |
48 | { | |
8bd1209c HX |
49 | int bs = crypto_shash_blocksize(parent); |
50 | int ds = crypto_shash_digestsize(parent); | |
51 | char *ipad = crypto_shash_ctx_aligned(parent); | |
0796ae06 HX |
52 | char *opad = ipad + bs; |
53 | char *digest = opad + bs; | |
8bd1209c HX |
54 | struct hmac_ctx *ctx = align_ptr(digest + ds, |
55 | crypto_tfm_ctx_alignment()); | |
0796ae06 HX |
56 | unsigned int i; |
57 | ||
58 | if (keylen > bs) { | |
0796ae06 HX |
59 | int err; |
60 | ||
8bd1209c HX |
61 | ctx->desc->flags = crypto_shash_get_flags(parent) & |
62 | CRYPTO_TFM_REQ_MAY_SLEEP; | |
0796ae06 | 63 | |
8bd1209c | 64 | err = crypto_shash_digest(ctx->desc, inkey, keylen, digest); |
0796ae06 HX |
65 | if (err) |
66 | return err; | |
67 | ||
68 | inkey = digest; | |
69 | keylen = ds; | |
70 | } | |
71 | ||
72 | memcpy(ipad, inkey, keylen); | |
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 0; | |
82 | } | |
83 | ||
8bd1209c | 84 | static int hmac_init(struct shash_desc *pdesc) |
0796ae06 | 85 | { |
8bd1209c HX |
86 | struct crypto_shash *parent = pdesc->tfm; |
87 | int bs = crypto_shash_blocksize(parent); | |
88 | int ds = crypto_shash_digestsize(parent); | |
89 | char *ipad = crypto_shash_ctx_aligned(parent); | |
90 | struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, | |
91 | crypto_tfm_ctx_alignment()); | |
92 | struct shash_desc *desc = shash_desc_ctx(pdesc); | |
93 | ||
94 | desc->tfm = ctx->desc->tfm; | |
95 | desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; | |
96 | ||
97 | return crypto_shash_init(desc) ?: | |
98 | crypto_shash_update(desc, ipad, bs); | |
0796ae06 HX |
99 | } |
100 | ||
8bd1209c HX |
101 | static int hmac_update(struct shash_desc *pdesc, |
102 | const u8 *data, unsigned int nbytes) | |
0796ae06 | 103 | { |
8bd1209c | 104 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 105 | |
8bd1209c | 106 | desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; |
0796ae06 | 107 | |
8bd1209c | 108 | return crypto_shash_update(desc, data, nbytes); |
0796ae06 HX |
109 | } |
110 | ||
8bd1209c | 111 | static int hmac_final(struct shash_desc *pdesc, u8 *out) |
0796ae06 | 112 | { |
8bd1209c HX |
113 | struct crypto_shash *parent = pdesc->tfm; |
114 | int bs = crypto_shash_blocksize(parent); | |
115 | int ds = crypto_shash_digestsize(parent); | |
116 | char *opad = crypto_shash_ctx_aligned(parent) + bs; | |
0796ae06 | 117 | char *digest = opad + bs; |
8bd1209c | 118 | struct shash_desc *desc = shash_desc_ctx(pdesc); |
0796ae06 | 119 | |
8bd1209c | 120 | desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; |
73af07de | 121 | |
8bd1209c HX |
122 | return crypto_shash_final(desc, digest) ?: |
123 | crypto_shash_digest(desc, opad, bs + ds, out); | |
0796ae06 HX |
124 | } |
125 | ||
8bd1209c HX |
126 | static int hmac_finup(struct shash_desc *pdesc, const u8 *data, |
127 | unsigned int nbytes, u8 *out) | |
0796ae06 | 128 | { |
0796ae06 | 129 | |
8bd1209c HX |
130 | struct crypto_shash *parent = pdesc->tfm; |
131 | int bs = crypto_shash_blocksize(parent); | |
132 | int ds = crypto_shash_digestsize(parent); | |
133 | char *opad = crypto_shash_ctx_aligned(parent) + bs; | |
134 | char *digest = opad + bs; | |
135 | struct shash_desc *desc = shash_desc_ctx(pdesc); | |
78c2f0b8 | 136 | |
8bd1209c | 137 | desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; |
0796ae06 | 138 | |
8bd1209c HX |
139 | return crypto_shash_finup(desc, data, nbytes, digest) ?: |
140 | crypto_shash_digest(desc, opad, bs + ds, out); | |
0796ae06 HX |
141 | } |
142 | ||
143 | static int hmac_init_tfm(struct crypto_tfm *tfm) | |
144 | { | |
8bd1209c HX |
145 | struct crypto_shash *parent = __crypto_shash_cast(tfm); |
146 | struct crypto_shash *hash; | |
0796ae06 | 147 | struct crypto_instance *inst = (void *)tfm->__crt_alg; |
8bd1209c HX |
148 | struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst); |
149 | struct hmac_ctx *ctx = hmac_ctx(parent); | |
0796ae06 | 150 | |
8bd1209c | 151 | hash = crypto_spawn_shash(spawn); |
2e306ee0 HX |
152 | if (IS_ERR(hash)) |
153 | return PTR_ERR(hash); | |
0796ae06 | 154 | |
8bd1209c HX |
155 | parent->descsize = sizeof(struct shash_desc) + |
156 | crypto_shash_descsize(hash); | |
157 | ||
158 | ctx->desc = kmalloc(parent->descsize, GFP_KERNEL); | |
159 | if (!ctx->desc) { | |
160 | crypto_free_shash(hash); | |
161 | return -ENOMEM; | |
162 | } | |
163 | ||
164 | ctx->desc->tfm = hash; | |
0796ae06 HX |
165 | return 0; |
166 | } | |
167 | ||
168 | static void hmac_exit_tfm(struct crypto_tfm *tfm) | |
169 | { | |
8bd1209c HX |
170 | struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm)); |
171 | crypto_free_shash(ctx->desc->tfm); | |
172 | kzfree(ctx->desc); | |
0796ae06 HX |
173 | } |
174 | ||
8bd1209c | 175 | static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb) |
0796ae06 | 176 | { |
8bd1209c | 177 | struct shash_instance *inst; |
0796ae06 | 178 | struct crypto_alg *alg; |
8bd1209c | 179 | struct shash_alg *salg; |
ebc610e5 | 180 | int err; |
ca786dc7 | 181 | int ds; |
ebc610e5 | 182 | |
8bd1209c | 183 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); |
ebc610e5 | 184 | if (err) |
8bd1209c HX |
185 | return err; |
186 | ||
187 | salg = shash_attr_alg(tb[1], 0, 0); | |
188 | if (IS_ERR(salg)) | |
189 | return PTR_ERR(salg); | |
190 | ||
191 | err = -EINVAL; | |
192 | ds = salg->digestsize; | |
193 | alg = &salg->base; | |
ca786dc7 HX |
194 | if (ds > alg->cra_blocksize) |
195 | goto out_put_alg; | |
196 | ||
8bd1209c | 197 | inst = shash_alloc_instance("hmac", alg); |
0796ae06 HX |
198 | if (IS_ERR(inst)) |
199 | goto out_put_alg; | |
200 | ||
8bd1209c HX |
201 | err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg, |
202 | shash_crypto_instance(inst)); | |
203 | if (err) | |
204 | goto out_free_inst; | |
205 | ||
206 | inst->alg.base.cra_priority = alg->cra_priority; | |
207 | inst->alg.base.cra_blocksize = alg->cra_blocksize; | |
208 | inst->alg.base.cra_alignmask = alg->cra_alignmask; | |
0796ae06 | 209 | |
8bd1209c | 210 | inst->alg.digestsize = ds; |
0796ae06 | 211 | |
8bd1209c HX |
212 | inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) + |
213 | ALIGN(alg->cra_blocksize * 2 + ds, | |
214 | crypto_tfm_ctx_alignment()); | |
0796ae06 | 215 | |
8bd1209c HX |
216 | inst->alg.base.cra_init = hmac_init_tfm; |
217 | inst->alg.base.cra_exit = hmac_exit_tfm; | |
0796ae06 | 218 | |
8bd1209c HX |
219 | inst->alg.init = hmac_init; |
220 | inst->alg.update = hmac_update; | |
221 | inst->alg.final = hmac_final; | |
222 | inst->alg.finup = hmac_finup; | |
223 | inst->alg.setkey = hmac_setkey; | |
224 | ||
225 | err = shash_register_instance(tmpl, inst); | |
226 | if (err) { | |
227 | out_free_inst: | |
228 | shash_free_instance(shash_crypto_instance(inst)); | |
229 | } | |
0796ae06 HX |
230 | |
231 | out_put_alg: | |
232 | crypto_mod_put(alg); | |
8bd1209c | 233 | return err; |
0796ae06 HX |
234 | } |
235 | ||
236 | static struct crypto_template hmac_tmpl = { | |
237 | .name = "hmac", | |
8bd1209c HX |
238 | .create = hmac_create, |
239 | .free = shash_free_instance, | |
0796ae06 HX |
240 | .module = THIS_MODULE, |
241 | }; | |
242 | ||
243 | static int __init hmac_module_init(void) | |
244 | { | |
245 | return crypto_register_template(&hmac_tmpl); | |
246 | } | |
247 | ||
248 | static void __exit hmac_module_exit(void) | |
249 | { | |
250 | crypto_unregister_template(&hmac_tmpl); | |
251 | } | |
252 | ||
253 | module_init(hmac_module_init); | |
254 | module_exit(hmac_module_exit); | |
255 | ||
256 | MODULE_LICENSE("GPL"); | |
257 | MODULE_DESCRIPTION("HMAC hash algorithm"); |