[CRYPTO] sha: Load the SHA[1|256] module by an alias
[linux-2.6.git] / drivers / crypto / padlock-sha.c
1 /*
2  * Cryptographic API.
3  *
4  * Support for VIA PadLock hardware crypto engine.
5  *
6  * Copyright (c) 2006  Michal Ludvig <michal@logix.cz>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  */
14
15 #include <crypto/algapi.h>
16 #include <linux/err.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/errno.h>
20 #include <linux/cryptohash.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/scatterlist.h>
24 #include "padlock.h"
25
26 #define SHA1_DEFAULT_FALLBACK   "sha1-generic"
27 #define SHA1_DIGEST_SIZE        20
28 #define SHA1_HMAC_BLOCK_SIZE    64
29
30 #define SHA256_DEFAULT_FALLBACK "sha256-generic"
31 #define SHA256_DIGEST_SIZE      32
32 #define SHA256_HMAC_BLOCK_SIZE  64
33
34 struct padlock_sha_ctx {
35         char            *data;
36         size_t          used;
37         int             bypass;
38         void (*f_sha_padlock)(const char *in, char *out, int count);
39         struct hash_desc fallback;
40 };
41
42 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
43 {
44         return crypto_tfm_ctx(tfm);
45 }
46
47 /* We'll need aligned address on the stack */
48 #define NEAREST_ALIGNED(ptr) \
49         ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
50
51 static struct crypto_alg sha1_alg, sha256_alg;
52
53 static void padlock_sha_bypass(struct crypto_tfm *tfm)
54 {
55         if (ctx(tfm)->bypass)
56                 return;
57
58         crypto_hash_init(&ctx(tfm)->fallback);
59         if (ctx(tfm)->data && ctx(tfm)->used) {
60                 struct scatterlist sg;
61
62                 sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used);
63                 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
64         }
65
66         ctx(tfm)->used = 0;
67         ctx(tfm)->bypass = 1;
68 }
69
70 static void padlock_sha_init(struct crypto_tfm *tfm)
71 {
72         ctx(tfm)->used = 0;
73         ctx(tfm)->bypass = 0;
74 }
75
76 static void padlock_sha_update(struct crypto_tfm *tfm,
77                         const uint8_t *data, unsigned int length)
78 {
79         /* Our buffer is always one page. */
80         if (unlikely(!ctx(tfm)->bypass &&
81                      (ctx(tfm)->used + length > PAGE_SIZE)))
82                 padlock_sha_bypass(tfm);
83
84         if (unlikely(ctx(tfm)->bypass)) {
85                 struct scatterlist sg;
86                 sg_set_buf(&sg, (uint8_t *)data, length);
87                 crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
88                 return;
89         }
90
91         memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
92         ctx(tfm)->used += length;
93 }
94
95 static inline void padlock_output_block(uint32_t *src,
96                         uint32_t *dst, size_t count)
97 {
98         while (count--)
99                 *dst++ = swab32(*src++);
100 }
101
102 static void padlock_do_sha1(const char *in, char *out, int count)
103 {
104         /* We can't store directly to *out as it may be unaligned. */
105         /* BTW Don't reduce the buffer size below 128 Bytes!
106          *     PadLock microcode needs it that big. */
107         char buf[128+16];
108         char *result = NEAREST_ALIGNED(buf);
109
110         ((uint32_t *)result)[0] = 0x67452301;
111         ((uint32_t *)result)[1] = 0xEFCDAB89;
112         ((uint32_t *)result)[2] = 0x98BADCFE;
113         ((uint32_t *)result)[3] = 0x10325476;
114         ((uint32_t *)result)[4] = 0xC3D2E1F0;
115  
116         asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
117                       : "+S"(in), "+D"(result)
118                       : "c"(count), "a"(0));
119
120         padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
121 }
122
123 static void padlock_do_sha256(const char *in, char *out, int count)
124 {
125         /* We can't store directly to *out as it may be unaligned. */
126         /* BTW Don't reduce the buffer size below 128 Bytes!
127          *     PadLock microcode needs it that big. */
128         char buf[128+16];
129         char *result = NEAREST_ALIGNED(buf);
130
131         ((uint32_t *)result)[0] = 0x6A09E667;
132         ((uint32_t *)result)[1] = 0xBB67AE85;
133         ((uint32_t *)result)[2] = 0x3C6EF372;
134         ((uint32_t *)result)[3] = 0xA54FF53A;
135         ((uint32_t *)result)[4] = 0x510E527F;
136         ((uint32_t *)result)[5] = 0x9B05688C;
137         ((uint32_t *)result)[6] = 0x1F83D9AB;
138         ((uint32_t *)result)[7] = 0x5BE0CD19;
139
140         asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
141                       : "+S"(in), "+D"(result)
142                       : "c"(count), "a"(0));
143
144         padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
145 }
146
147 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
148 {
149         if (unlikely(ctx(tfm)->bypass)) {
150                 crypto_hash_final(&ctx(tfm)->fallback, out);
151                 ctx(tfm)->bypass = 0;
152                 return;
153         }
154
155         /* Pass the input buffer to PadLock microcode... */
156         ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
157
158         ctx(tfm)->used = 0;
159 }
160
161 static int padlock_cra_init(struct crypto_tfm *tfm)
162 {
163         const char *fallback_driver_name = tfm->__crt_alg->cra_name;
164         struct crypto_hash *fallback_tfm;
165
166         /* For now we'll allocate one page. This
167          * could eventually be configurable one day. */
168         ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
169         if (!ctx(tfm)->data)
170                 return -ENOMEM;
171
172         /* Allocate a fallback and abort if it failed. */
173         fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
174                                          CRYPTO_ALG_ASYNC |
175                                          CRYPTO_ALG_NEED_FALLBACK);
176         if (IS_ERR(fallback_tfm)) {
177                 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
178                        fallback_driver_name);
179                 free_page((unsigned long)(ctx(tfm)->data));
180                 return PTR_ERR(fallback_tfm);
181         }
182
183         ctx(tfm)->fallback.tfm = fallback_tfm;
184         return 0;
185 }
186
187 static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
188 {
189         ctx(tfm)->f_sha_padlock = padlock_do_sha1;
190
191         return padlock_cra_init(tfm);
192 }
193
194 static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
195 {
196         ctx(tfm)->f_sha_padlock = padlock_do_sha256;
197
198         return padlock_cra_init(tfm);
199 }
200
201 static void padlock_cra_exit(struct crypto_tfm *tfm)
202 {
203         if (ctx(tfm)->data) {
204                 free_page((unsigned long)(ctx(tfm)->data));
205                 ctx(tfm)->data = NULL;
206         }
207
208         crypto_free_hash(ctx(tfm)->fallback.tfm);
209         ctx(tfm)->fallback.tfm = NULL;
210 }
211
212 static struct crypto_alg sha1_alg = {
213         .cra_name               =       "sha1",
214         .cra_driver_name        =       "sha1-padlock",
215         .cra_priority           =       PADLOCK_CRA_PRIORITY,
216         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
217                                         CRYPTO_ALG_NEED_FALLBACK,
218         .cra_blocksize          =       SHA1_HMAC_BLOCK_SIZE,
219         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
220         .cra_module             =       THIS_MODULE,
221         .cra_list               =       LIST_HEAD_INIT(sha1_alg.cra_list),
222         .cra_init               =       padlock_sha1_cra_init,
223         .cra_exit               =       padlock_cra_exit,
224         .cra_u                  =       {
225                 .digest = {
226                         .dia_digestsize =       SHA1_DIGEST_SIZE,
227                         .dia_init       =       padlock_sha_init,
228                         .dia_update     =       padlock_sha_update,
229                         .dia_final      =       padlock_sha_final,
230                 }
231         }
232 };
233
234 static struct crypto_alg sha256_alg = {
235         .cra_name               =       "sha256",
236         .cra_driver_name        =       "sha256-padlock",
237         .cra_priority           =       PADLOCK_CRA_PRIORITY,
238         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
239                                         CRYPTO_ALG_NEED_FALLBACK,
240         .cra_blocksize          =       SHA256_HMAC_BLOCK_SIZE,
241         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
242         .cra_module             =       THIS_MODULE,
243         .cra_list               =       LIST_HEAD_INIT(sha256_alg.cra_list),
244         .cra_init               =       padlock_sha256_cra_init,
245         .cra_exit               =       padlock_cra_exit,
246         .cra_u                  =       {
247                 .digest = {
248                         .dia_digestsize =       SHA256_DIGEST_SIZE,
249                         .dia_init       =       padlock_sha_init,
250                         .dia_update     =       padlock_sha_update,
251                         .dia_final      =       padlock_sha_final,
252                 }
253         }
254 };
255
256 static int __init padlock_init(void)
257 {
258         int rc = -ENODEV;
259
260         if (!cpu_has_phe) {
261                 printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
262                 return -ENODEV;
263         }
264
265         if (!cpu_has_phe_enabled) {
266                 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
267                 return -ENODEV;
268         }
269
270         rc = crypto_register_alg(&sha1_alg);
271         if (rc)
272                 goto out;
273
274         rc = crypto_register_alg(&sha256_alg);
275         if (rc)
276                 goto out_unreg1;
277
278         printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
279
280         return 0;
281
282 out_unreg1:
283         crypto_unregister_alg(&sha1_alg);
284 out:
285         printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
286         return rc;
287 }
288
289 static void __exit padlock_fini(void)
290 {
291         crypto_unregister_alg(&sha1_alg);
292         crypto_unregister_alg(&sha256_alg);
293 }
294
295 module_init(padlock_init);
296 module_exit(padlock_fini);
297
298 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
299 MODULE_LICENSE("GPL");
300 MODULE_AUTHOR("Michal Ludvig");
301
302 MODULE_ALIAS("sha1");
303 MODULE_ALIAS("sha256");
304 MODULE_ALIAS("sha1-padlock");
305 MODULE_ALIAS("sha256-padlock");