xref: /freebsd/crypto/openssl/engines/e_padlock.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 2004-2023 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 /*
11  * This file uses the low level AES and engine functions (which are deprecated
12  * for non-internal use) in order to implement the padlock engine AES ciphers.
13  */
14 #define OPENSSL_SUPPRESS_DEPRECATED
15 
16 #include <stdio.h>
17 #include <string.h>
18 
19 #include <openssl/opensslconf.h>
20 #include <openssl/crypto.h>
21 #include <openssl/engine.h>
22 #include <openssl/evp.h>
23 #include <openssl/aes.h>
24 #include <openssl/rand.h>
25 #include <openssl/err.h>
26 #include <openssl/modes.h>
27 
28 #ifndef OPENSSL_NO_PADLOCKENG
29 
30 /*
31  * VIA PadLock AES is available *ONLY* on some x86 CPUs. Not only that it
32  * doesn't exist elsewhere, but it even can't be compiled on other platforms!
33  */
34 
35 #undef COMPILE_PADLOCKENG
36 #if defined(PADLOCK_ASM)
37 #define COMPILE_PADLOCKENG
38 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
39 static ENGINE *ENGINE_padlock(void);
40 #endif
41 #endif
42 
43 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
44 void engine_load_padlock_int(void);
45 void engine_load_padlock_int(void)
46 {
47 /* On non-x86 CPUs it just returns. */
48 #ifdef COMPILE_PADLOCKENG
49     ENGINE *toadd = ENGINE_padlock();
50     if (!toadd)
51         return;
52     ERR_set_mark();
53     ENGINE_add(toadd);
54     /*
55      * If the "add" worked, it gets a structural reference. So either way, we
56      * release our just-created reference.
57      */
58     ENGINE_free(toadd);
59     /*
60      * If the "add" didn't work, it was probably a conflict because it was
61      * already added (eg. someone calling ENGINE_load_blah then calling
62      * ENGINE_load_builtin_engines() perhaps).
63      */
64     ERR_pop_to_mark();
65 #endif
66 }
67 
68 #endif
69 
70 #ifdef COMPILE_PADLOCKENG
71 
72 /* Function for ENGINE detection and control */
73 static int padlock_available(void);
74 static int padlock_init(ENGINE *e);
75 
76 /* RNG Stuff */
77 static RAND_METHOD padlock_rand;
78 
79 /* Cipher Stuff */
80 static int padlock_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
81     const int **nids, int nid);
82 
83 /* Engine names */
84 static const char *padlock_id = "padlock";
85 static char padlock_name[100];
86 
87 /* Available features */
88 static int padlock_use_ace = 0; /* Advanced Cryptography Engine */
89 static int padlock_use_rng = 0; /* Random Number Generator */
90 
91 /* ===== Engine "management" functions ===== */
92 
93 /* Prepare the ENGINE structure for registration */
94 static int padlock_bind_helper(ENGINE *e)
95 {
96     /* Check available features */
97     padlock_available();
98 
99     /*
100      * RNG is currently disabled for reasons discussed in commentary just
101      * before padlock_rand_bytes function.
102      */
103     padlock_use_rng = 0;
104 
105     /* Generate a nice engine name with available features */
106     BIO_snprintf(padlock_name, sizeof(padlock_name),
107         "VIA PadLock (%s, %s)",
108         padlock_use_rng ? "RNG" : "no-RNG",
109         padlock_use_ace ? "ACE" : "no-ACE");
110 
111     /* Register everything or return with an error */
112     if (!ENGINE_set_id(e, padlock_id) || !ENGINE_set_name(e, padlock_name) || !ENGINE_set_init_function(e, padlock_init) || (padlock_use_ace && !ENGINE_set_ciphers(e, padlock_ciphers)) || (padlock_use_rng && !ENGINE_set_RAND(e, &padlock_rand))) {
113         return 0;
114     }
115 
116     /* Everything looks good */
117     return 1;
118 }
119 
120 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
121 /* Constructor */
122 static ENGINE *ENGINE_padlock(void)
123 {
124     ENGINE *eng = ENGINE_new();
125 
126     if (eng == NULL) {
127         return NULL;
128     }
129 
130     if (!padlock_bind_helper(eng)) {
131         ENGINE_free(eng);
132         return NULL;
133     }
134 
135     return eng;
136 }
137 #endif
138 
139 /* Check availability of the engine */
140 static int padlock_init(ENGINE *e)
141 {
142     return (padlock_use_rng || padlock_use_ace);
143 }
144 
145 #ifndef AES_ASM
146 static int padlock_aes_set_encrypt_key(const unsigned char *userKey,
147     const int bits,
148     AES_KEY *key);
149 static int padlock_aes_set_decrypt_key(const unsigned char *userKey,
150     const int bits,
151     AES_KEY *key);
152 #define AES_ASM
153 #define AES_set_encrypt_key padlock_aes_set_encrypt_key
154 #define AES_set_decrypt_key padlock_aes_set_decrypt_key
155 /* clang-format off */
156 #   include "../crypto/aes/aes_core.c"
157 /* clang-format on */
158 #endif
159 
160 /*
161  * This stuff is needed if this ENGINE is being compiled into a
162  * self-contained shared-library.
163  */
164 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
165 static int padlock_bind_fn(ENGINE *e, const char *id)
166 {
167     if (id && (strcmp(id, padlock_id) != 0)) {
168         return 0;
169     }
170 
171     if (!padlock_bind_helper(e)) {
172         return 0;
173     }
174 
175     return 1;
176 }
177 
178 IMPLEMENT_DYNAMIC_CHECK_FN()
179 IMPLEMENT_DYNAMIC_BIND_FN(padlock_bind_fn)
180 #endif /* !OPENSSL_NO_DYNAMIC_ENGINE */
181 /* ===== Here comes the "real" engine ===== */
182 
183 /* Some AES-related constants */
184 #define AES_BLOCK_SIZE 16
185 #define AES_KEY_SIZE_128 16
186 #define AES_KEY_SIZE_192 24
187 #define AES_KEY_SIZE_256 32
188 /*
189  * Here we store the status information relevant to the current context.
190  */
191 /*
192  * BIG FAT WARNING: Inline assembler in PADLOCK_XCRYPT_ASM() depends on
193  * the order of items in this structure.  Don't blindly modify, reorder,
194  * etc!
195  */
196 struct padlock_cipher_data {
197     unsigned char iv[AES_BLOCK_SIZE]; /* Initialization vector */
198     union {
199         unsigned int pad[4];
200         struct {
201             int rounds : 4;
202             int dgst : 1; /* n/a in C3 */
203             int align : 1; /* n/a in C3 */
204             int ciphr : 1; /* n/a in C3 */ /* codespell:ignore */
205             unsigned int keygen : 1;
206             int interm : 1; /* codespell:ignore */
207             unsigned int encdec : 1;
208             int ksize : 2;
209         } b;
210     } cword; /* Control word */
211     AES_KEY ks; /* Encryption key */
212 };
213 
214 /* Interface to assembler module */
215 unsigned int padlock_capability(void);
216 void padlock_key_bswap(AES_KEY *key);
217 void padlock_verify_context(struct padlock_cipher_data *ctx);
218 void padlock_reload_key(void);
219 void padlock_aes_block(void *out, const void *inp,
220     struct padlock_cipher_data *ctx);
221 int padlock_ecb_encrypt(void *out, const void *inp,
222     struct padlock_cipher_data *ctx, size_t len);
223 int padlock_cbc_encrypt(void *out, const void *inp,
224     struct padlock_cipher_data *ctx, size_t len);
225 int padlock_cfb_encrypt(void *out, const void *inp,
226     struct padlock_cipher_data *ctx, size_t len);
227 int padlock_ofb_encrypt(void *out, const void *inp,
228     struct padlock_cipher_data *ctx, size_t len);
229 int padlock_ctr32_encrypt(void *out, const void *inp,
230     struct padlock_cipher_data *ctx, size_t len);
231 int padlock_xstore(void *out, int edx);
232 void padlock_sha1_oneshot(void *ctx, const void *inp, size_t len);
233 void padlock_sha1(void *ctx, const void *inp, size_t len);
234 void padlock_sha256_oneshot(void *ctx, const void *inp, size_t len);
235 void padlock_sha256(void *ctx, const void *inp, size_t len);
236 
237 /*
238  * Load supported features of the CPU to see if the PadLock is available.
239  */
240 static int padlock_available(void)
241 {
242     unsigned int edx = padlock_capability();
243 
244     /* Fill up some flags */
245     padlock_use_ace = ((edx & (0x3 << 6)) == (0x3 << 6));
246     padlock_use_rng = ((edx & (0x3 << 2)) == (0x3 << 2));
247 
248     return padlock_use_ace + padlock_use_rng;
249 }
250 
251 /* ===== AES encryption/decryption ===== */
252 
253 #if defined(NID_aes_128_cfb128) && !defined(NID_aes_128_cfb)
254 #define NID_aes_128_cfb NID_aes_128_cfb128
255 #endif
256 
257 #if defined(NID_aes_128_ofb128) && !defined(NID_aes_128_ofb)
258 #define NID_aes_128_ofb NID_aes_128_ofb128
259 #endif
260 
261 #if defined(NID_aes_192_cfb128) && !defined(NID_aes_192_cfb)
262 #define NID_aes_192_cfb NID_aes_192_cfb128
263 #endif
264 
265 #if defined(NID_aes_192_ofb128) && !defined(NID_aes_192_ofb)
266 #define NID_aes_192_ofb NID_aes_192_ofb128
267 #endif
268 
269 #if defined(NID_aes_256_cfb128) && !defined(NID_aes_256_cfb)
270 #define NID_aes_256_cfb NID_aes_256_cfb128
271 #endif
272 
273 #if defined(NID_aes_256_ofb128) && !defined(NID_aes_256_ofb)
274 #define NID_aes_256_ofb NID_aes_256_ofb128
275 #endif
276 
277 /* List of supported ciphers. */
278 static const int padlock_cipher_nids[] = {
279     NID_aes_128_ecb,
280     NID_aes_128_cbc,
281     NID_aes_128_cfb,
282     NID_aes_128_ofb,
283     NID_aes_128_ctr,
284 
285     NID_aes_192_ecb,
286     NID_aes_192_cbc,
287     NID_aes_192_cfb,
288     NID_aes_192_ofb,
289     NID_aes_192_ctr,
290 
291     NID_aes_256_ecb,
292     NID_aes_256_cbc,
293     NID_aes_256_cfb,
294     NID_aes_256_ofb,
295     NID_aes_256_ctr
296 };
297 
298 static int padlock_cipher_nids_num = (sizeof(padlock_cipher_nids) / sizeof(padlock_cipher_nids[0]));
299 
300 /* Function prototypes ... */
301 static int padlock_aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
302     const unsigned char *iv, int enc);
303 
304 #define NEAREST_ALIGNED(ptr) ((unsigned char *)(ptr) + ((0x10 - ((size_t)(ptr) & 0x0F)) & 0x0F))
305 #define ALIGNED_CIPHER_DATA(ctx) ((struct padlock_cipher_data *) \
306         NEAREST_ALIGNED(EVP_CIPHER_CTX_get_cipher_data(ctx)))
307 
308 static int
309 padlock_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,
310     const unsigned char *in_arg, size_t nbytes)
311 {
312     return padlock_ecb_encrypt(out_arg, in_arg,
313         ALIGNED_CIPHER_DATA(ctx), nbytes);
314 }
315 
316 static int
317 padlock_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,
318     const unsigned char *in_arg, size_t nbytes)
319 {
320     struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);
321     int ret;
322 
323     memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);
324     if ((ret = padlock_cbc_encrypt(out_arg, in_arg, cdata, nbytes)))
325         memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);
326     return ret;
327 }
328 
329 static int
330 padlock_cfb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,
331     const unsigned char *in_arg, size_t nbytes)
332 {
333     struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);
334     size_t chunk;
335 
336     if ((chunk = EVP_CIPHER_CTX_get_num(ctx))) { /* borrow chunk variable */
337         unsigned char *ivp = EVP_CIPHER_CTX_iv_noconst(ctx);
338 
339         if (chunk >= AES_BLOCK_SIZE)
340             return 0; /* bogus value */
341 
342         if (EVP_CIPHER_CTX_is_encrypting(ctx))
343             while (chunk < AES_BLOCK_SIZE && nbytes != 0) {
344                 ivp[chunk] = *(out_arg++) = *(in_arg++) ^ ivp[chunk];
345                 chunk++, nbytes--;
346             }
347         else
348             while (chunk < AES_BLOCK_SIZE && nbytes != 0) {
349                 unsigned char c = *(in_arg++);
350                 *(out_arg++) = c ^ ivp[chunk];
351                 ivp[chunk++] = c, nbytes--;
352             }
353 
354         EVP_CIPHER_CTX_set_num(ctx, chunk % AES_BLOCK_SIZE);
355     }
356 
357     if (nbytes == 0)
358         return 1;
359 
360     memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);
361 
362     if ((chunk = nbytes & ~(AES_BLOCK_SIZE - 1))) {
363         if (!padlock_cfb_encrypt(out_arg, in_arg, cdata, chunk))
364             return 0;
365         nbytes -= chunk;
366     }
367 
368     if (nbytes) {
369         unsigned char *ivp = cdata->iv;
370 
371         out_arg += chunk;
372         in_arg += chunk;
373         EVP_CIPHER_CTX_set_num(ctx, nbytes);
374         if (cdata->cword.b.encdec) {
375             cdata->cword.b.encdec = 0;
376             padlock_reload_key();
377             padlock_aes_block(ivp, ivp, cdata);
378             cdata->cword.b.encdec = 1;
379             padlock_reload_key();
380             while (nbytes) {
381                 unsigned char c = *(in_arg++);
382                 *(out_arg++) = c ^ *ivp;
383                 *(ivp++) = c, nbytes--;
384             }
385         } else {
386             padlock_reload_key();
387             padlock_aes_block(ivp, ivp, cdata);
388             padlock_reload_key();
389             while (nbytes) {
390                 *ivp = *(out_arg++) = *(in_arg++) ^ *ivp;
391                 ivp++, nbytes--;
392             }
393         }
394     }
395 
396     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);
397 
398     return 1;
399 }
400 
401 static int
402 padlock_ofb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,
403     const unsigned char *in_arg, size_t nbytes)
404 {
405     struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);
406     size_t chunk;
407 
408     /*
409      * ctx->num is maintained in byte-oriented modes, such as CFB and OFB...
410      */
411     if ((chunk = EVP_CIPHER_CTX_get_num(ctx))) { /* borrow chunk variable */
412         unsigned char *ivp = EVP_CIPHER_CTX_iv_noconst(ctx);
413 
414         if (chunk >= AES_BLOCK_SIZE)
415             return 0; /* bogus value */
416 
417         while (chunk < AES_BLOCK_SIZE && nbytes != 0) {
418             *(out_arg++) = *(in_arg++) ^ ivp[chunk];
419             chunk++, nbytes--;
420         }
421 
422         EVP_CIPHER_CTX_set_num(ctx, chunk % AES_BLOCK_SIZE);
423     }
424 
425     if (nbytes == 0)
426         return 1;
427 
428     memcpy(cdata->iv, EVP_CIPHER_CTX_iv(ctx), AES_BLOCK_SIZE);
429 
430     if ((chunk = nbytes & ~(AES_BLOCK_SIZE - 1))) {
431         if (!padlock_ofb_encrypt(out_arg, in_arg, cdata, chunk))
432             return 0;
433         nbytes -= chunk;
434     }
435 
436     if (nbytes) {
437         unsigned char *ivp = cdata->iv;
438 
439         out_arg += chunk;
440         in_arg += chunk;
441         EVP_CIPHER_CTX_set_num(ctx, nbytes);
442         padlock_reload_key(); /* empirically found */
443         padlock_aes_block(ivp, ivp, cdata);
444         padlock_reload_key(); /* empirically found */
445         while (nbytes) {
446             *(out_arg++) = *(in_arg++) ^ *ivp;
447             ivp++, nbytes--;
448         }
449     }
450 
451     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), cdata->iv, AES_BLOCK_SIZE);
452 
453     return 1;
454 }
455 
456 static void padlock_ctr32_encrypt_glue(const unsigned char *in,
457     unsigned char *out, size_t blocks,
458     struct padlock_cipher_data *ctx,
459     const unsigned char *ivec)
460 {
461     memcpy(ctx->iv, ivec, AES_BLOCK_SIZE);
462     padlock_ctr32_encrypt(out, in, ctx, AES_BLOCK_SIZE * blocks);
463 }
464 
465 static int
466 padlock_ctr_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out_arg,
467     const unsigned char *in_arg, size_t nbytes)
468 {
469     struct padlock_cipher_data *cdata = ALIGNED_CIPHER_DATA(ctx);
470     int n = EVP_CIPHER_CTX_get_num(ctx);
471     unsigned int num;
472 
473     if (n < 0)
474         return 0;
475     num = (unsigned int)n;
476 
477     CRYPTO_ctr128_encrypt_ctr32(in_arg, out_arg, nbytes,
478         cdata, EVP_CIPHER_CTX_iv_noconst(ctx),
479         EVP_CIPHER_CTX_buf_noconst(ctx), &num,
480         (ctr128_f)padlock_ctr32_encrypt_glue);
481 
482     EVP_CIPHER_CTX_set_num(ctx, (size_t)num);
483     return 1;
484 }
485 
486 #define EVP_CIPHER_block_size_ECB AES_BLOCK_SIZE
487 #define EVP_CIPHER_block_size_CBC AES_BLOCK_SIZE
488 #define EVP_CIPHER_block_size_OFB 1
489 #define EVP_CIPHER_block_size_CFB 1
490 #define EVP_CIPHER_block_size_CTR 1
491 
492 /*
493  * Declaring so many ciphers by hand would be a pain. Instead introduce a bit
494  * of preprocessor magic :-)
495  */
496 #define DECLARE_AES_EVP(ksize, lmode, umode)                                                    \
497     static EVP_CIPHER *_hidden_aes_##ksize##_##lmode = NULL;                                    \
498     static const EVP_CIPHER *padlock_aes_##ksize##_##lmode(void)                                \
499     {                                                                                           \
500         if (_hidden_aes_##ksize##_##lmode == NULL                                               \
501             && ((_hidden_aes_##ksize##_##lmode = EVP_CIPHER_meth_new(NID_aes_##ksize##_##lmode, \
502                      EVP_CIPHER_block_size_##umode,                                             \
503                      AES_KEY_SIZE_##ksize))                                                     \
504                     == NULL                                                                     \
505                 || !EVP_CIPHER_meth_set_iv_length(_hidden_aes_##ksize##_##lmode,                \
506                     AES_BLOCK_SIZE)                                                             \
507                 || !EVP_CIPHER_meth_set_flags(_hidden_aes_##ksize##_##lmode,                    \
508                     0 | EVP_CIPH_##umode##_MODE)                                                \
509                 || !EVP_CIPHER_meth_set_init(_hidden_aes_##ksize##_##lmode,                     \
510                     padlock_aes_init_key)                                                       \
511                 || !EVP_CIPHER_meth_set_do_cipher(_hidden_aes_##ksize##_##lmode,                \
512                     padlock_##lmode##_cipher)                                                   \
513                 || !EVP_CIPHER_meth_set_impl_ctx_size(_hidden_aes_##ksize##_##lmode,            \
514                     sizeof(struct padlock_cipher_data) + 16)                                    \
515                 || !EVP_CIPHER_meth_set_set_asn1_params(_hidden_aes_##ksize##_##lmode,          \
516                     EVP_CIPHER_set_asn1_iv)                                                     \
517                 || !EVP_CIPHER_meth_set_get_asn1_params(_hidden_aes_##ksize##_##lmode,          \
518                     EVP_CIPHER_get_asn1_iv))) {                                                 \
519             EVP_CIPHER_meth_free(_hidden_aes_##ksize##_##lmode);                                \
520             _hidden_aes_##ksize##_##lmode = NULL;                                               \
521         }                                                                                       \
522         return _hidden_aes_##ksize##_##lmode;                                                   \
523     }
524 
525 DECLARE_AES_EVP(128, ecb, ECB)
526 DECLARE_AES_EVP(128, cbc, CBC)
527 DECLARE_AES_EVP(128, cfb, CFB)
528 DECLARE_AES_EVP(128, ofb, OFB)
529 DECLARE_AES_EVP(128, ctr, CTR)
530 
531 DECLARE_AES_EVP(192, ecb, ECB)
532 DECLARE_AES_EVP(192, cbc, CBC)
533 DECLARE_AES_EVP(192, cfb, CFB)
534 DECLARE_AES_EVP(192, ofb, OFB)
535 DECLARE_AES_EVP(192, ctr, CTR)
536 
537 DECLARE_AES_EVP(256, ecb, ECB)
538 DECLARE_AES_EVP(256, cbc, CBC)
539 DECLARE_AES_EVP(256, cfb, CFB)
540 DECLARE_AES_EVP(256, ofb, OFB)
541 DECLARE_AES_EVP(256, ctr, CTR)
542 
543 static int
544 padlock_ciphers(ENGINE *e, const EVP_CIPHER **cipher, const int **nids,
545     int nid)
546 {
547     /* No specific cipher => return a list of supported nids ... */
548     if (!cipher) {
549         *nids = padlock_cipher_nids;
550         return padlock_cipher_nids_num;
551     }
552 
553     /* ... or the requested "cipher" otherwise */
554     switch (nid) {
555     case NID_aes_128_ecb:
556         *cipher = padlock_aes_128_ecb();
557         break;
558     case NID_aes_128_cbc:
559         *cipher = padlock_aes_128_cbc();
560         break;
561     case NID_aes_128_cfb:
562         *cipher = padlock_aes_128_cfb();
563         break;
564     case NID_aes_128_ofb:
565         *cipher = padlock_aes_128_ofb();
566         break;
567     case NID_aes_128_ctr:
568         *cipher = padlock_aes_128_ctr();
569         break;
570 
571     case NID_aes_192_ecb:
572         *cipher = padlock_aes_192_ecb();
573         break;
574     case NID_aes_192_cbc:
575         *cipher = padlock_aes_192_cbc();
576         break;
577     case NID_aes_192_cfb:
578         *cipher = padlock_aes_192_cfb();
579         break;
580     case NID_aes_192_ofb:
581         *cipher = padlock_aes_192_ofb();
582         break;
583     case NID_aes_192_ctr:
584         *cipher = padlock_aes_192_ctr();
585         break;
586 
587     case NID_aes_256_ecb:
588         *cipher = padlock_aes_256_ecb();
589         break;
590     case NID_aes_256_cbc:
591         *cipher = padlock_aes_256_cbc();
592         break;
593     case NID_aes_256_cfb:
594         *cipher = padlock_aes_256_cfb();
595         break;
596     case NID_aes_256_ofb:
597         *cipher = padlock_aes_256_ofb();
598         break;
599     case NID_aes_256_ctr:
600         *cipher = padlock_aes_256_ctr();
601         break;
602 
603     default:
604         /* Sorry, we don't support this NID */
605         *cipher = NULL;
606         return 0;
607     }
608 
609     return 1;
610 }
611 
612 /* Prepare the encryption key for PadLock usage */
613 static int
614 padlock_aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
615     const unsigned char *iv, int enc)
616 {
617     struct padlock_cipher_data *cdata;
618     int key_len = EVP_CIPHER_CTX_get_key_length(ctx) * 8;
619     unsigned long mode = EVP_CIPHER_CTX_get_mode(ctx);
620 
621     if (key == NULL)
622         return 0; /* ERROR */
623 
624     cdata = ALIGNED_CIPHER_DATA(ctx);
625     memset(cdata, 0, sizeof(*cdata));
626 
627     /* Prepare Control word. */
628     if (mode == EVP_CIPH_OFB_MODE || mode == EVP_CIPH_CTR_MODE)
629         cdata->cword.b.encdec = 0;
630     else
631         cdata->cword.b.encdec = (EVP_CIPHER_CTX_is_encrypting(ctx) == 0);
632     cdata->cword.b.rounds = 10 + (key_len - 128) / 32;
633     cdata->cword.b.ksize = (key_len - 128) / 64;
634 
635     switch (key_len) {
636     case 128:
637         /*
638          * PadLock can generate an extended key for AES128 in hardware
639          */
640         memcpy(cdata->ks.rd_key, key, AES_KEY_SIZE_128);
641         cdata->cword.b.keygen = 0;
642         break;
643 
644     case 192:
645     case 256:
646         /*
647          * Generate an extended AES key in software. Needed for AES192/AES256
648          */
649         /*
650          * Well, the above applies to Stepping 8 CPUs and is listed as
651          * hardware errata. They most likely will fix it at some point and
652          * then a check for stepping would be due here.
653          */
654         if ((mode == EVP_CIPH_ECB_MODE || mode == EVP_CIPH_CBC_MODE)
655             && !enc)
656             AES_set_decrypt_key(key, key_len, &cdata->ks);
657         else
658             AES_set_encrypt_key(key, key_len, &cdata->ks);
659         /*
660          * OpenSSL C functions use byte-swapped extended key.
661          */
662         padlock_key_bswap(&cdata->ks);
663         cdata->cword.b.keygen = 1;
664         break;
665 
666     default:
667         /* ERROR */
668         return 0;
669     }
670 
671     /*
672      * This is done to cover for cases when user reuses the
673      * context for new key. The catch is that if we don't do
674      * this, padlock_eas_cipher might proceed with old key...
675      */
676     padlock_reload_key();
677 
678     return 1;
679 }
680 
681 /* ===== Random Number Generator ===== */
682 /*
683  * This code is not engaged. The reason is that it does not comply
684  * with recommendations for VIA RNG usage for secure applications
685  * (posted at http://www.via.com.tw/en/viac3/c3.jsp) nor does it
686  * provide meaningful error control...
687  */
688 /*
689  * Wrapper that provides an interface between the API and the raw PadLock
690  * RNG
691  */
692 static int padlock_rand_bytes(unsigned char *output, int count)
693 {
694     unsigned int eax, buf;
695 
696     while (count >= 8) {
697         eax = padlock_xstore(output, 0);
698         if (!(eax & (1 << 6)))
699             return 0; /* RNG disabled */
700         /* this ---vv--- covers DC bias, Raw Bits and String Filter */
701         if (eax & (0x1F << 10))
702             return 0;
703         if ((eax & 0x1F) == 0)
704             continue; /* no data, retry... */
705         if ((eax & 0x1F) != 8)
706             return 0; /* fatal failure...  */
707         output += 8;
708         count -= 8;
709     }
710     while (count > 0) {
711         eax = padlock_xstore(&buf, 3);
712         if (!(eax & (1 << 6)))
713             return 0; /* RNG disabled */
714         /* this ---vv--- covers DC bias, Raw Bits and String Filter */
715         if (eax & (0x1F << 10))
716             return 0;
717         if ((eax & 0x1F) == 0)
718             continue; /* no data, retry... */
719         if ((eax & 0x1F) != 1)
720             return 0; /* fatal failure...  */
721         *output++ = (unsigned char)buf;
722         count--;
723     }
724     OPENSSL_cleanse(&buf, sizeof(buf));
725 
726     return 1;
727 }
728 
729 /* Dummy but necessary function */
730 static int padlock_rand_status(void)
731 {
732     return 1;
733 }
734 
735 /* Prepare structure for registration */
736 static RAND_METHOD padlock_rand = {
737     NULL, /* seed */
738     padlock_rand_bytes, /* bytes */
739     NULL, /* cleanup */
740     NULL, /* add */
741     padlock_rand_bytes, /* pseudorand */
742     padlock_rand_status, /* rand status */
743 };
744 
745 #endif /* COMPILE_PADLOCKENG */
746 #endif /* !OPENSSL_NO_PADLOCKENG */
747 
748 #if defined(OPENSSL_NO_PADLOCKENG) || !defined(COMPILE_PADLOCKENG)
749 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
750 OPENSSL_EXPORT
751 int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns);
752 OPENSSL_EXPORT
753 int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns)
754 {
755     return 0;
756 }
757 
758 IMPLEMENT_DYNAMIC_CHECK_FN()
759 #endif
760 #endif
761