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 <asm/i387.h>
26 #include "padlock.h"
27
28 #define SHA1_DEFAULT_FALLBACK "sha1-generic"
29 #define SHA256_DEFAULT_FALLBACK "sha256-generic"
30
31 struct padlock_sha_ctx {
32 char *data;
33 size_t used;
34 int bypass;
35 void (*f_sha_padlock)(const char *in, char *out, int count);
36 struct hash_desc fallback;
37 };
38
39 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm)
40 {
41 return crypto_tfm_ctx(tfm);
42 }
43
44 /* We'll need aligned address on the stack */
45 #define NEAREST_ALIGNED(ptr) \
46 ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT))
47
48 static struct crypto_alg sha1_alg, sha256_alg;
49
50 static void padlock_sha_bypass(struct crypto_tfm *tfm)
51 {
52 if (ctx(tfm)->bypass)
53 return;
54
55 crypto_hash_init(&ctx(tfm)->fallback);
56 if (ctx(tfm)->data && ctx(tfm)->used) {
57 struct scatterlist sg;
58
59 sg_init_one(&sg, ctx(tfm)->data, ctx(tfm)->used);
60 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length);
61 }
62
63 ctx(tfm)->used = 0;
64 ctx(tfm)->bypass = 1;
65 }
66
67 static void padlock_sha_init(struct crypto_tfm *tfm)
68 {
69 ctx(tfm)->used = 0;
70 ctx(tfm)->bypass = 0;
71 }
72
73 static void padlock_sha_update(struct crypto_tfm *tfm,
74 const uint8_t *data, unsigned int length)
75 {
76 /* Our buffer is always one page. */
77 if (unlikely(!ctx(tfm)->bypass &&
78 (ctx(tfm)->used + length > PAGE_SIZE)))
79 padlock_sha_bypass(tfm);
80
81 if (unlikely(ctx(tfm)->bypass)) {
82 struct scatterlist sg;
83 sg_init_one(&sg, (uint8_t *)data, length);
84 crypto_hash_update(&ctx(tfm)->fallback, &sg, length);
85 return;
86 }
87
88 memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length);
89 ctx(tfm)->used += length;
90 }
91
92 static inline void padlock_output_block(uint32_t *src,
93 uint32_t *dst, size_t count)
94 {
95 while (count--)
96 *dst++ = swab32(*src++);
97 }
98
99 static void padlock_do_sha1(const char *in, char *out, int count)
100 {
101 /* We can't store directly to *out as it may be unaligned. */
102 /* BTW Don't reduce the buffer size below 128 Bytes!
103 * PadLock microcode needs it that big. */
104 char buf[128+16];
105 char *result = NEAREST_ALIGNED(buf);
106 int ts_state;
107
108 ((uint32_t *)result)[0] = SHA1_H0;
109 ((uint32_t *)result)[1] = SHA1_H1;
110 ((uint32_t *)result)[2] = SHA1_H2;
111 ((uint32_t *)result)[3] = SHA1_H3;
112 ((uint32_t *)result)[4] = SHA1_H4;
113
114 /* prevent taking the spurious DNA fault with padlock. */
115 ts_state = irq_ts_save();
116 asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */
117 : "+S"(in), "+D"(result)
118 : "c"(count), "a"(0));
119 irq_ts_restore(ts_state);
120
121 padlock_output_block((uint32_t *)result, (uint32_t *)out, 5);
122 }
123
124 static void padlock_do_sha256(const char *in, char *out, int count)
125 {
126 /* We can't store directly to *out as it may be unaligned. */
127 /* BTW Don't reduce the buffer size below 128 Bytes!
128 * PadLock microcode needs it that big. */
129 char buf[128+16];
130 char *result = NEAREST_ALIGNED(buf);
131 int ts_state;
132
133 ((uint32_t *)result)[0] = SHA256_H0;
134 ((uint32_t *)result)[1] = SHA256_H1;
135 ((uint32_t *)result)[2] = SHA256_H2;
136 ((uint32_t *)result)[3] = SHA256_H3;
137 ((uint32_t *)result)[4] = SHA256_H4;
138 ((uint32_t *)result)[5] = SHA256_H5;
139 ((uint32_t *)result)[6] = SHA256_H6;
140 ((uint32_t *)result)[7] = SHA256_H7;
141
142 /* prevent taking the spurious DNA fault with padlock. */
143 ts_state = irq_ts_save();
144 asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */
145 : "+S"(in), "+D"(result)
146 : "c"(count), "a"(0));
147 irq_ts_restore(ts_state);
148
149 padlock_output_block((uint32_t *)result, (uint32_t *)out, 8);
150 }
151
152 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out)
153 {
154 if (unlikely(ctx(tfm)->bypass)) {
155 crypto_hash_final(&ctx(tfm)->fallback, out);
156 ctx(tfm)->bypass = 0;
157 return;
158 }
159
160 /* Pass the input buffer to PadLock microcode... */
161 ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used);
162
163 ctx(tfm)->used = 0;
164 }
165
166 static int padlock_cra_init(struct crypto_tfm *tfm)
167 {
168 const char *fallback_driver_name = tfm->__crt_alg->cra_name;
169 struct crypto_hash *fallback_tfm;
170
171 /* For now we'll allocate one page. This
172 * could eventually be configurable one day. */
173 ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL);
174 if (!ctx(tfm)->data)
175 return -ENOMEM;
176
177 /* Allocate a fallback and abort if it failed. */
178 fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0,
179 CRYPTO_ALG_ASYNC |
180 CRYPTO_ALG_NEED_FALLBACK);
181 if (IS_ERR(fallback_tfm)) {
182 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n",
183 fallback_driver_name);
184 free_page((unsigned long)(ctx(tfm)->data));
185 return PTR_ERR(fallback_tfm);
186 }
187
188 ctx(tfm)->fallback.tfm = fallback_tfm;
189 return 0;
190 }
191
192 static int padlock_sha1_cra_init(struct crypto_tfm *tfm)
193 {
194 ctx(tfm)->f_sha_padlock = padlock_do_sha1;
195
196 return padlock_cra_init(tfm);
197 }
198
199 static int padlock_sha256_cra_init(struct crypto_tfm *tfm)
200 {
201 ctx(tfm)->f_sha_padlock = padlock_do_sha256;
202
203 return padlock_cra_init(tfm);
204 }
205
206 static void padlock_cra_exit(struct crypto_tfm *tfm)
207 {
208 if (ctx(tfm)->data) {
209 free_page((unsigned long)(ctx(tfm)->data));
210 ctx(tfm)->data = NULL;
211 }
212
213 crypto_free_hash(ctx(tfm)->fallback.tfm);
214 ctx(tfm)->fallback.tfm = NULL;
215 }
216
217 static struct crypto_alg sha1_alg = {
218 .cra_name = "sha1",
219 .cra_driver_name = "sha1-padlock",
220 .cra_priority = PADLOCK_CRA_PRIORITY,
221 .cra_flags = CRYPTO_ALG_TYPE_DIGEST |
222 CRYPTO_ALG_NEED_FALLBACK,
223 .cra_blocksize = SHA1_BLOCK_SIZE,
224 .cra_ctxsize = sizeof(struct padlock_sha_ctx),
225 .cra_module = THIS_MODULE,
226 .cra_list = LIST_HEAD_INIT(sha1_alg.cra_list),
227 .cra_init = padlock_sha1_cra_init,
228 .cra_exit = padlock_cra_exit,
229 .cra_u = {
230 .digest = {
231 .dia_digestsize = SHA1_DIGEST_SIZE,
232 .dia_init = padlock_sha_init,
233 .dia_update = padlock_sha_update,
234 .dia_final = padlock_sha_final,
235 }
236 }
237 };
238
239 static struct crypto_alg sha256_alg = {
240 .cra_name = "sha256",
241 .cra_driver_name = "sha256-padlock",
242 .cra_priority = PADLOCK_CRA_PRIORITY,
243 .cra_flags = CRYPTO_ALG_TYPE_DIGEST |
244 CRYPTO_ALG_NEED_FALLBACK,
245 .cra_blocksize = SHA256_BLOCK_SIZE,
246 .cra_ctxsize = sizeof(struct padlock_sha_ctx),
247 .cra_module = THIS_MODULE,
248 .cra_list = LIST_HEAD_INIT(sha256_alg.cra_list),
249 .cra_init = padlock_sha256_cra_init,
250 .cra_exit = padlock_cra_exit,
251 .cra_u = {
252 .digest = {
253 .dia_digestsize = SHA256_DIGEST_SIZE,
254 .dia_init = padlock_sha_init,
255 .dia_update = padlock_sha_update,
256 .dia_final = padlock_sha_final,
257 }
258 }
259 };
260
261 static int __init padlock_init(void)
262 {
263 int rc = -ENODEV;
264
265 if (!cpu_has_phe) {
266 printk(KERN_NOTICE PFX "VIA PadLock Hash Engine not detected.\n");
267 return -ENODEV;
268 }
269
270 if (!cpu_has_phe_enabled) {
271 printk(KERN_NOTICE PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n");
272 return -ENODEV;
273 }
274
275 rc = crypto_register_alg(&sha1_alg);
276 if (rc)
277 goto out;
278
279 rc = crypto_register_alg(&sha256_alg);
280 if (rc)
281 goto out_unreg1;
282
283 printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n");
284
285 return 0;
286
287 out_unreg1:
288 crypto_unregister_alg(&sha1_alg);
289 out:
290 printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n");
291 return rc;
292 }
293
294 static void __exit padlock_fini(void)
295 {
296 crypto_unregister_alg(&sha1_alg);
297 crypto_unregister_alg(&sha256_alg);
298 }
299
300 module_init(padlock_init);
301 module_exit(padlock_fini);
302
303 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support.");
304 MODULE_LICENSE("GPL");
305 MODULE_AUTHOR("Michal Ludvig");
306
307 MODULE_ALIAS("sha1-all");
308 MODULE_ALIAS("sha256-all");
309 MODULE_ALIAS("sha1-padlock");
310 MODULE_ALIAS("sha256-padlock");
311
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