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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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 <crypto/sha.h>
 17 #include <linux/err.h>
 18 #include <linux/module.h>
 19 #include <linux/init.h>
 20 #include <linux/errno.h>
 21 #include <linux/cryptohash.h>
 22 #include <linux/interrupt.h>
 23 #include <linux/kernel.h>
 24 #include <linux/scatterlist.h>
 25 #include "padlock.h"
 26 
 27 #define SHA1_DEFAULT_FALLBACK   "sha1-generic"
 28 #define SHA256_DEFAULT_FALLBACK "sha256-generic"
 29 
 30 struct padlock_sha_ctx {
 31         char            *data;
 32         size_t          used;
 33         int             bypass;
 34         void (*f_sha_padlock)(const char *in, char *out, int count);
 35         struct hash_desc fallback;
 36 };
 37 
 38 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
 39 {
 40         return crypto_tfm_ctx(tfm);
 41 }
 42 
 43 /* We'll need aligned address on the stack */
 44 #define NEAREST_ALIGNED(ptr) \
 45         ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
 46 
 47 static struct crypto_alg sha1_alg, sha256_alg;
 48 
 49 static void padlock_sha_bypass(struct crypto_tfm *tfm)
 50 {
 51         if (ctx(tfm)->bypass)
 52                 return;
 53 
 54         crypto_hash_init(&ctx(tfm)->fallback);
 55         if (ctx(tfm)->data && ctx(tfm)->used) {
 56                 struct scatterlist sg;
 57 
 58                 sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
 59                 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
 60         }
 61 
 62         ctx(tfm)->used = 0;
 63         ctx(tfm)->bypass = 1;
 64 }
 65 
 66 static void padlock_sha_init(struct crypto_tfm *tfm)
 67 {
 68         ctx(tfm)->used = 0;
 69         ctx(tfm)->bypass = 0;
 70 }
 71 
 72 static void padlock_sha_update(struct crypto_tfm *tfm,
 73                         const uint8_t *data, unsigned int length)
 74 {
 75         /* Our buffer is always one page. */
 76         if (unlikely(!ctx(tfm)->bypass &&
 77                      (ctx(tfm)->used + length > PAGE_SIZE)))
 78                 padlock_sha_bypass(tfm);
 79 
 80         if (unlikely(ctx(tfm)->bypass)) {
 81                 struct scatterlist sg;
 82                 sg_init_one(&sg, (uint8_t *)data, length);
 83                 crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
 84                 return;
 85         }
 86 
 87         memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
 88         ctx(tfm)->used += length;
 89 }
 90 
 91 static inline void padlock_output_block(uint32_t *src,
 92                         uint32_t *dst, size_t count)
 93 {
 94         while (count--)
 95                 *dst++ = swab32(*src++);
 96 }
 97 
 98 static void padlock_do_sha1(const char *in, char *out, int count)
 99 {
100         /* We can't store directly to *out as it may be unaligned. */
101         /* BTW Don't reduce the buffer size below 128 Bytes!
102          *     PadLock microcode needs it that big. */
103         char buf[128+16];
104         char *result = NEAREST_ALIGNED(buf);
105 
106         ((uint32_t *)result)[0] = SHA1_H0;
107         ((uint32_t *)result)[1] = SHA1_H1;
108         ((uint32_t *)result)[2] = SHA1_H2;
109         ((uint32_t *)result)[3] = SHA1_H3;
110         ((uint32_t *)result)[4] = SHA1_H4;
111  
112         asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
113                       : "+S"(in), "+D"(result)
114                       : "c"(count), "a"(0));
115 
116         padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
117 }
118 
119 static void padlock_do_sha256(const char *in, char *out, int count)
120 {
121         /* We can't store directly to *out as it may be unaligned. */
122         /* BTW Don't reduce the buffer size below 128 Bytes!
123          *     PadLock microcode needs it that big. */
124         char buf[128+16];
125         char *result = NEAREST_ALIGNED(buf);
126 
127         ((uint32_t *)result)[0] = SHA256_H0;
128         ((uint32_t *)result)[1] = SHA256_H1;
129         ((uint32_t *)result)[2] = SHA256_H2;
130         ((uint32_t *)result)[3] = SHA256_H3;
131         ((uint32_t *)result)[4] = SHA256_H4;
132         ((uint32_t *)result)[5] = SHA256_H5;
133         ((uint32_t *)result)[6] = SHA256_H6;
134         ((uint32_t *)result)[7] = SHA256_H7;
135 
136         asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
137                       : "+S"(in), "+D"(result)
138                       : "c"(count), "a"(0));
139 
140         padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
141 }
142 
143 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
144 {
145         if (unlikely(ctx(tfm)->bypass)) {
146                 crypto_hash_final(&ctx(tfm)->fallback, out);
147                 ctx(tfm)->bypass = 0;
148                 return;
149         }
150 
151         /* Pass the input buffer to PadLock microcode... */
152         ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
153 
154         ctx(tfm)->used = 0;
155 }
156 
157 static int padlock_cra_init(struct crypto_tfm *tfm)
158 {
159         const char *fallback_driver_name = tfm->__crt_alg->cra_name;
160         struct crypto_hash *fallback_tfm;
161 
162         /* For now we'll allocate one page. This
163          * could eventually be configurable one day. */
164         ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
165         if (!ctx(tfm)->data)
166                 return -ENOMEM;
167 
168         /* Allocate a fallback and abort if it failed. */
169         fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
170                                          CRYPTO_ALG_ASYNC |
171                                          CRYPTO_ALG_NEED_FALLBACK);
172         if (IS_ERR(fallback_tfm)) {
173                 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
174                        fallback_driver_name);
175                 free_page((unsigned long)(ctx(tfm)->data));
176                 return PTR_ERR(fallback_tfm);
177         }
178 
179         ctx(tfm)->fallback.tfm = fallback_tfm;
180         return 0;
181 }
182 
183 static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
184 {
185         ctx(tfm)->f_sha_padlock = padlock_do_sha1;
186 
187         return padlock_cra_init(tfm);
188 }
189 
190 static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
191 {
192         ctx(tfm)->f_sha_padlock = padlock_do_sha256;
193 
194         return padlock_cra_init(tfm);
195 }
196 
197 static void padlock_cra_exit(struct crypto_tfm *tfm)
198 {
199         if (ctx(tfm)->data) {
200                 free_page((unsigned long)(ctx(tfm)->data));
201                 ctx(tfm)->data = NULL;
202         }
203 
204         crypto_free_hash(ctx(tfm)->fallback.tfm);
205         ctx(tfm)->fallback.tfm = NULL;
206 }
207 
208 static struct crypto_alg sha1_alg = {
209         .cra_name               =       "sha1",
210         .cra_driver_name        =       "sha1-padlock",
211         .cra_priority           =       PADLOCK_CRA_PRIORITY,
212         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
213                                         CRYPTO_ALG_NEED_FALLBACK,
214         .cra_blocksize          =       SHA1_BLOCK_SIZE,
215         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
216         .cra_module             =       THIS_MODULE,
217         .cra_list               =       LIST_HEAD_INIT(sha1_alg.cra_list),
218         .cra_init               =       padlock_sha1_cra_init,
219         .cra_exit               =       padlock_cra_exit,
220         .cra_u                  =       {
221                 .digest = {
222                         .dia_digestsize =       SHA1_DIGEST_SIZE,
223                         .dia_init       =       padlock_sha_init,
224                         .dia_update     =       padlock_sha_update,
225                         .dia_final      =       padlock_sha_final,
226                 }
227         }
228 };
229 
230 static struct crypto_alg sha256_alg = {
231         .cra_name               =       "sha256",
232         .cra_driver_name        =       "sha256-padlock",
233         .cra_priority           =       PADLOCK_CRA_PRIORITY,
234         .cra_flags              =       CRYPTO_ALG_TYPE_DIGEST |
235                                         CRYPTO_ALG_NEED_FALLBACK,
236         .cra_blocksize          =       SHA256_BLOCK_SIZE,
237         .cra_ctxsize            =       sizeof(struct padlock_sha_ctx),
238         .cra_module             =       THIS_MODULE,
239         .cra_list               =       LIST_HEAD_INIT(sha256_alg.cra_list),
240         .cra_init               =       padlock_sha256_cra_init,
241         .cra_exit               =       padlock_cra_exit,
242         .cra_u                  =       {
243                 .digest = {
244                         .dia_digestsize =       SHA256_DIGEST_SIZE,
245                         .dia_init       =       padlock_sha_init,
246                         .dia_update     =       padlock_sha_update,
247                         .dia_final      =       padlock_sha_final,
248                 }
249         }
250 };
251 
252 static int __init padlock_init(void)
253 {
254         int rc = -ENODEV;
255 
256         if (!cpu_has_phe) {
257                 printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n");
258                 return -ENODEV;
259         }
260 
261         if (!cpu_has_phe_enabled) {
262                 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
263                 return -ENODEV;
264         }
265 
266         rc = crypto_register_alg(&sha1_alg);
267         if (rc)
268                 goto out;
269 
270         rc = crypto_register_alg(&sha256_alg);
271         if (rc)
272                 goto out_unreg1;
273 
274         printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
275 
276         return 0;
277 
278 out_unreg1:
279         crypto_unregister_alg(&sha1_alg);
280 out:
281         printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
282         return rc;
283 }
284 
285 static void __exit padlock_fini(void)
286 {
287         crypto_unregister_alg(&sha1_alg);
288         crypto_unregister_alg(&sha256_alg);
289 }
290 
291 module_init(padlock_init);
292 module_exit(padlock_fini);
293 
294 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
295 MODULE_LICENSE("GPL");
296 MODULE_AUTHOR("Michal Ludvig");
297 
298 MODULE_ALIAS("sha1");
299 MODULE_ALIAS("sha256");
300 MODULE_ALIAS("sha1-padlock");
301 MODULE_ALIAS("sha256-padlock");
302 
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