xref: /freebsd/crypto/openssl/engines/e_ossltest.c (revision d66820f2c8c6cdc3d0359abf1004dac0a466a01d)
1 /*
2  * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (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 is the OSSLTEST engine. It provides deliberately crippled digest
12  * implementations for test purposes. It is highly insecure and must NOT be
13  * used for any purpose except testing
14  */
15 
16 #include <stdio.h>
17 #include <string.h>
18 
19 #include <openssl/engine.h>
20 #include <openssl/sha.h>
21 #include <openssl/md5.h>
22 #include <openssl/rsa.h>
23 #include <openssl/evp.h>
24 #include <openssl/modes.h>
25 #include <openssl/aes.h>
26 #include <openssl/rand.h>
27 #include <openssl/crypto.h>
28 
29 #include "e_ossltest_err.c"
30 
31 /* Engine Id and Name */
32 static const char *engine_ossltest_id = "ossltest";
33 static const char *engine_ossltest_name = "OpenSSL Test engine support";
34 
35 
36 /* Engine Lifetime functions */
37 static int ossltest_destroy(ENGINE *e);
38 static int ossltest_init(ENGINE *e);
39 static int ossltest_finish(ENGINE *e);
40 void ENGINE_load_ossltest(void);
41 
42 
43 /* Set up digests */
44 static int ossltest_digests(ENGINE *e, const EVP_MD **digest,
45                           const int **nids, int nid);
46 static const RAND_METHOD *ossltest_rand_method(void);
47 
48 /* MD5 */
49 static int digest_md5_init(EVP_MD_CTX *ctx);
50 static int digest_md5_update(EVP_MD_CTX *ctx, const void *data,
51                              size_t count);
52 static int digest_md5_final(EVP_MD_CTX *ctx, unsigned char *md);
53 
54 static EVP_MD *_hidden_md5_md = NULL;
55 static const EVP_MD *digest_md5(void)
56 {
57     if (_hidden_md5_md == NULL) {
58         EVP_MD *md;
59 
60         if ((md = EVP_MD_meth_new(NID_md5, NID_md5WithRSAEncryption)) == NULL
61             || !EVP_MD_meth_set_result_size(md, MD5_DIGEST_LENGTH)
62             || !EVP_MD_meth_set_input_blocksize(md, MD5_CBLOCK)
63             || !EVP_MD_meth_set_app_datasize(md,
64                                              sizeof(EVP_MD *) + sizeof(MD5_CTX))
65             || !EVP_MD_meth_set_flags(md, 0)
66             || !EVP_MD_meth_set_init(md, digest_md5_init)
67             || !EVP_MD_meth_set_update(md, digest_md5_update)
68             || !EVP_MD_meth_set_final(md, digest_md5_final)) {
69             EVP_MD_meth_free(md);
70             md = NULL;
71         }
72         _hidden_md5_md = md;
73     }
74     return _hidden_md5_md;
75 }
76 
77 /* SHA1 */
78 static int digest_sha1_init(EVP_MD_CTX *ctx);
79 static int digest_sha1_update(EVP_MD_CTX *ctx, const void *data,
80                               size_t count);
81 static int digest_sha1_final(EVP_MD_CTX *ctx, unsigned char *md);
82 
83 static EVP_MD *_hidden_sha1_md = NULL;
84 static const EVP_MD *digest_sha1(void)
85 {
86     if (_hidden_sha1_md == NULL) {
87         EVP_MD *md;
88 
89         if ((md = EVP_MD_meth_new(NID_sha1, NID_sha1WithRSAEncryption)) == NULL
90             || !EVP_MD_meth_set_result_size(md, SHA_DIGEST_LENGTH)
91             || !EVP_MD_meth_set_input_blocksize(md, SHA_CBLOCK)
92             || !EVP_MD_meth_set_app_datasize(md,
93                                              sizeof(EVP_MD *) + sizeof(SHA_CTX))
94             || !EVP_MD_meth_set_flags(md, EVP_MD_FLAG_DIGALGID_ABSENT)
95             || !EVP_MD_meth_set_init(md, digest_sha1_init)
96             || !EVP_MD_meth_set_update(md, digest_sha1_update)
97             || !EVP_MD_meth_set_final(md, digest_sha1_final)) {
98             EVP_MD_meth_free(md);
99             md = NULL;
100         }
101         _hidden_sha1_md = md;
102     }
103     return _hidden_sha1_md;
104 }
105 
106 /* SHA256 */
107 static int digest_sha256_init(EVP_MD_CTX *ctx);
108 static int digest_sha256_update(EVP_MD_CTX *ctx, const void *data,
109                                 size_t count);
110 static int digest_sha256_final(EVP_MD_CTX *ctx, unsigned char *md);
111 
112 static EVP_MD *_hidden_sha256_md = NULL;
113 static const EVP_MD *digest_sha256(void)
114 {
115     if (_hidden_sha256_md == NULL) {
116         EVP_MD *md;
117 
118         if ((md = EVP_MD_meth_new(NID_sha256, NID_sha256WithRSAEncryption)) == NULL
119             || !EVP_MD_meth_set_result_size(md, SHA256_DIGEST_LENGTH)
120             || !EVP_MD_meth_set_input_blocksize(md, SHA256_CBLOCK)
121             || !EVP_MD_meth_set_app_datasize(md,
122                                              sizeof(EVP_MD *) + sizeof(SHA256_CTX))
123             || !EVP_MD_meth_set_flags(md, EVP_MD_FLAG_DIGALGID_ABSENT)
124             || !EVP_MD_meth_set_init(md, digest_sha256_init)
125             || !EVP_MD_meth_set_update(md, digest_sha256_update)
126             || !EVP_MD_meth_set_final(md, digest_sha256_final)) {
127             EVP_MD_meth_free(md);
128             md = NULL;
129         }
130         _hidden_sha256_md = md;
131     }
132     return _hidden_sha256_md;
133 }
134 
135 /* SHA384/SHA512 */
136 static int digest_sha384_init(EVP_MD_CTX *ctx);
137 static int digest_sha512_init(EVP_MD_CTX *ctx);
138 static int digest_sha512_update(EVP_MD_CTX *ctx, const void *data,
139                                 size_t count);
140 static int digest_sha384_final(EVP_MD_CTX *ctx, unsigned char *md);
141 static int digest_sha512_final(EVP_MD_CTX *ctx, unsigned char *md);
142 
143 static EVP_MD *_hidden_sha384_md = NULL;
144 static const EVP_MD *digest_sha384(void)
145 {
146     if (_hidden_sha384_md == NULL) {
147         EVP_MD *md;
148 
149         if ((md = EVP_MD_meth_new(NID_sha384, NID_sha384WithRSAEncryption)) == NULL
150             || !EVP_MD_meth_set_result_size(md, SHA384_DIGEST_LENGTH)
151             || !EVP_MD_meth_set_input_blocksize(md, SHA512_CBLOCK)
152             || !EVP_MD_meth_set_app_datasize(md,
153                                              sizeof(EVP_MD *) + sizeof(SHA512_CTX))
154             || !EVP_MD_meth_set_flags(md, EVP_MD_FLAG_DIGALGID_ABSENT)
155             || !EVP_MD_meth_set_init(md, digest_sha384_init)
156             || !EVP_MD_meth_set_update(md, digest_sha512_update)
157             || !EVP_MD_meth_set_final(md, digest_sha384_final)) {
158             EVP_MD_meth_free(md);
159             md = NULL;
160         }
161         _hidden_sha384_md = md;
162     }
163     return _hidden_sha384_md;
164 }
165 static EVP_MD *_hidden_sha512_md = NULL;
166 static const EVP_MD *digest_sha512(void)
167 {
168     if (_hidden_sha512_md == NULL) {
169         EVP_MD *md;
170 
171         if ((md = EVP_MD_meth_new(NID_sha512, NID_sha512WithRSAEncryption)) == NULL
172             || !EVP_MD_meth_set_result_size(md, SHA512_DIGEST_LENGTH)
173             || !EVP_MD_meth_set_input_blocksize(md, SHA512_CBLOCK)
174             || !EVP_MD_meth_set_app_datasize(md,
175                                              sizeof(EVP_MD *) + sizeof(SHA512_CTX))
176             || !EVP_MD_meth_set_flags(md, EVP_MD_FLAG_DIGALGID_ABSENT)
177             || !EVP_MD_meth_set_init(md, digest_sha512_init)
178             || !EVP_MD_meth_set_update(md, digest_sha512_update)
179             || !EVP_MD_meth_set_final(md, digest_sha512_final)) {
180             EVP_MD_meth_free(md);
181             md = NULL;
182         }
183         _hidden_sha512_md = md;
184     }
185     return _hidden_sha512_md;
186 }
187 static void destroy_digests(void)
188 {
189     EVP_MD_meth_free(_hidden_md5_md);
190     _hidden_md5_md = NULL;
191     EVP_MD_meth_free(_hidden_sha1_md);
192     _hidden_sha1_md = NULL;
193     EVP_MD_meth_free(_hidden_sha256_md);
194     _hidden_sha256_md = NULL;
195     EVP_MD_meth_free(_hidden_sha384_md);
196     _hidden_sha384_md = NULL;
197     EVP_MD_meth_free(_hidden_sha512_md);
198     _hidden_sha512_md = NULL;
199 }
200 static int ossltest_digest_nids(const int **nids)
201 {
202     static int digest_nids[6] = { 0, 0, 0, 0, 0, 0 };
203     static int pos = 0;
204     static int init = 0;
205 
206     if (!init) {
207         const EVP_MD *md;
208         if ((md = digest_md5()) != NULL)
209             digest_nids[pos++] = EVP_MD_type(md);
210         if ((md = digest_sha1()) != NULL)
211             digest_nids[pos++] = EVP_MD_type(md);
212         if ((md = digest_sha256()) != NULL)
213             digest_nids[pos++] = EVP_MD_type(md);
214         if ((md = digest_sha384()) != NULL)
215             digest_nids[pos++] = EVP_MD_type(md);
216         if ((md = digest_sha512()) != NULL)
217             digest_nids[pos++] = EVP_MD_type(md);
218         digest_nids[pos] = 0;
219         init = 1;
220     }
221     *nids = digest_nids;
222     return pos;
223 }
224 
225 /* Setup ciphers */
226 static int ossltest_ciphers(ENGINE *, const EVP_CIPHER **,
227                             const int **, int);
228 
229 static int ossltest_cipher_nids[] = {
230     NID_aes_128_cbc, NID_aes_128_gcm, 0
231 };
232 
233 /* AES128 */
234 
235 int ossltest_aes128_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
236                              const unsigned char *iv, int enc);
237 int ossltest_aes128_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
238                                const unsigned char *in, size_t inl);
239 int ossltest_aes128_gcm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
240                              const unsigned char *iv, int enc);
241 int ossltest_aes128_gcm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
242                                const unsigned char *in, size_t inl);
243 static int ossltest_aes128_gcm_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
244                                     void *ptr);
245 
246 static EVP_CIPHER *_hidden_aes_128_cbc = NULL;
247 static const EVP_CIPHER *ossltest_aes_128_cbc(void)
248 {
249     if (_hidden_aes_128_cbc == NULL
250         && ((_hidden_aes_128_cbc = EVP_CIPHER_meth_new(NID_aes_128_cbc,
251                                                        16 /* block size */,
252                                                        16 /* key len */)) == NULL
253             || !EVP_CIPHER_meth_set_iv_length(_hidden_aes_128_cbc,16)
254             || !EVP_CIPHER_meth_set_flags(_hidden_aes_128_cbc,
255                                           EVP_CIPH_FLAG_DEFAULT_ASN1
256                                           | EVP_CIPH_CBC_MODE)
257             || !EVP_CIPHER_meth_set_init(_hidden_aes_128_cbc,
258                                          ossltest_aes128_init_key)
259             || !EVP_CIPHER_meth_set_do_cipher(_hidden_aes_128_cbc,
260                                               ossltest_aes128_cbc_cipher)
261             || !EVP_CIPHER_meth_set_impl_ctx_size(_hidden_aes_128_cbc,
262                                                   EVP_CIPHER_impl_ctx_size(EVP_aes_128_cbc())))) {
263         EVP_CIPHER_meth_free(_hidden_aes_128_cbc);
264         _hidden_aes_128_cbc = NULL;
265     }
266     return _hidden_aes_128_cbc;
267 }
268 static EVP_CIPHER *_hidden_aes_128_gcm = NULL;
269 
270 #define AES_GCM_FLAGS   (EVP_CIPH_FLAG_DEFAULT_ASN1 \
271                 | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER \
272                 | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT \
273                 | EVP_CIPH_CUSTOM_COPY |EVP_CIPH_FLAG_AEAD_CIPHER \
274                 | EVP_CIPH_GCM_MODE)
275 
276 static const EVP_CIPHER *ossltest_aes_128_gcm(void)
277 {
278     if (_hidden_aes_128_gcm == NULL
279         && ((_hidden_aes_128_gcm = EVP_CIPHER_meth_new(NID_aes_128_gcm,
280                                                        1 /* block size */,
281                                                        16 /* key len */)) == NULL
282             || !EVP_CIPHER_meth_set_iv_length(_hidden_aes_128_gcm,12)
283             || !EVP_CIPHER_meth_set_flags(_hidden_aes_128_gcm, AES_GCM_FLAGS)
284             || !EVP_CIPHER_meth_set_init(_hidden_aes_128_gcm,
285                                          ossltest_aes128_gcm_init_key)
286             || !EVP_CIPHER_meth_set_do_cipher(_hidden_aes_128_gcm,
287                                               ossltest_aes128_gcm_cipher)
288             || !EVP_CIPHER_meth_set_ctrl(_hidden_aes_128_gcm,
289                                               ossltest_aes128_gcm_ctrl)
290             || !EVP_CIPHER_meth_set_impl_ctx_size(_hidden_aes_128_gcm,
291                               EVP_CIPHER_impl_ctx_size(EVP_aes_128_gcm())))) {
292         EVP_CIPHER_meth_free(_hidden_aes_128_gcm);
293         _hidden_aes_128_gcm = NULL;
294     }
295     return _hidden_aes_128_gcm;
296 }
297 
298 static void destroy_ciphers(void)
299 {
300     EVP_CIPHER_meth_free(_hidden_aes_128_cbc);
301     EVP_CIPHER_meth_free(_hidden_aes_128_gcm);
302     _hidden_aes_128_cbc = NULL;
303 }
304 
305 static int bind_ossltest(ENGINE *e)
306 {
307     /* Ensure the ossltest error handling is set up */
308     ERR_load_OSSLTEST_strings();
309 
310     if (!ENGINE_set_id(e, engine_ossltest_id)
311         || !ENGINE_set_name(e, engine_ossltest_name)
312         || !ENGINE_set_digests(e, ossltest_digests)
313         || !ENGINE_set_ciphers(e, ossltest_ciphers)
314         || !ENGINE_set_RAND(e, ossltest_rand_method())
315         || !ENGINE_set_destroy_function(e, ossltest_destroy)
316         || !ENGINE_set_init_function(e, ossltest_init)
317         || !ENGINE_set_finish_function(e, ossltest_finish)) {
318         OSSLTESTerr(OSSLTEST_F_BIND_OSSLTEST, OSSLTEST_R_INIT_FAILED);
319         return 0;
320     }
321 
322     return 1;
323 }
324 
325 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
326 static int bind_helper(ENGINE *e, const char *id)
327 {
328     if (id && (strcmp(id, engine_ossltest_id) != 0))
329         return 0;
330     if (!bind_ossltest(e))
331         return 0;
332     return 1;
333 }
334 
335 IMPLEMENT_DYNAMIC_CHECK_FN()
336     IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
337 #endif
338 
339 static ENGINE *engine_ossltest(void)
340 {
341     ENGINE *ret = ENGINE_new();
342     if (ret == NULL)
343         return NULL;
344     if (!bind_ossltest(ret)) {
345         ENGINE_free(ret);
346         return NULL;
347     }
348     return ret;
349 }
350 
351 void ENGINE_load_ossltest(void)
352 {
353     /* Copied from eng_[openssl|dyn].c */
354     ENGINE *toadd = engine_ossltest();
355     if (!toadd)
356         return;
357     ENGINE_add(toadd);
358     ENGINE_free(toadd);
359     ERR_clear_error();
360 }
361 
362 
363 static int ossltest_init(ENGINE *e)
364 {
365     return 1;
366 }
367 
368 
369 static int ossltest_finish(ENGINE *e)
370 {
371     return 1;
372 }
373 
374 
375 static int ossltest_destroy(ENGINE *e)
376 {
377     destroy_digests();
378     destroy_ciphers();
379     ERR_unload_OSSLTEST_strings();
380     return 1;
381 }
382 
383 static int ossltest_digests(ENGINE *e, const EVP_MD **digest,
384                           const int **nids, int nid)
385 {
386     int ok = 1;
387     if (!digest) {
388         /* We are returning a list of supported nids */
389         return ossltest_digest_nids(nids);
390     }
391     /* We are being asked for a specific digest */
392     switch (nid) {
393     case NID_md5:
394         *digest = digest_md5();
395         break;
396     case NID_sha1:
397         *digest = digest_sha1();
398         break;
399     case NID_sha256:
400         *digest = digest_sha256();
401         break;
402     case NID_sha384:
403         *digest = digest_sha384();
404         break;
405     case NID_sha512:
406         *digest = digest_sha512();
407         break;
408     default:
409         ok = 0;
410         *digest = NULL;
411         break;
412     }
413     return ok;
414 }
415 
416 static int ossltest_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
417                           const int **nids, int nid)
418 {
419     int ok = 1;
420     if (!cipher) {
421         /* We are returning a list of supported nids */
422         *nids = ossltest_cipher_nids;
423         return (sizeof(ossltest_cipher_nids) - 1)
424                / sizeof(ossltest_cipher_nids[0]);
425     }
426     /* We are being asked for a specific cipher */
427     switch (nid) {
428     case NID_aes_128_cbc:
429         *cipher = ossltest_aes_128_cbc();
430         break;
431     case NID_aes_128_gcm:
432         *cipher = ossltest_aes_128_gcm();
433         break;
434     default:
435         ok = 0;
436         *cipher = NULL;
437         break;
438     }
439     return ok;
440 }
441 
442 static void fill_known_data(unsigned char *md, unsigned int len)
443 {
444     unsigned int i;
445 
446     for (i=0; i<len; i++) {
447         md[i] = (unsigned char)(i & 0xff);
448     }
449 }
450 
451 /*
452  * MD5 implementation. We go through the motions of doing MD5 by deferring to
453  * the standard implementation. Then we overwrite the result with a will defined
454  * value, so that all "MD5" digests using the test engine always end up with
455  * the same value.
456  */
457 #undef data
458 #define data(ctx) ((MD5_CTX *)EVP_MD_CTX_md_data(ctx))
459 static int digest_md5_init(EVP_MD_CTX *ctx)
460 {
461     return MD5_Init(data(ctx));
462 }
463 
464 static int digest_md5_update(EVP_MD_CTX *ctx, const void *data,
465                              size_t count)
466 {
467     return MD5_Update(data(ctx), data, (size_t)count);
468 }
469 
470 static int digest_md5_final(EVP_MD_CTX *ctx, unsigned char *md)
471 {
472     int ret;
473     ret = MD5_Final(md, data(ctx));
474 
475     if (ret > 0) {
476         fill_known_data(md, MD5_DIGEST_LENGTH);
477     }
478     return ret;
479 }
480 
481 /*
482  * SHA1 implementation.
483  */
484 #undef data
485 #define data(ctx) ((SHA_CTX *)EVP_MD_CTX_md_data(ctx))
486 static int digest_sha1_init(EVP_MD_CTX *ctx)
487 {
488     return SHA1_Init(data(ctx));
489 }
490 
491 static int digest_sha1_update(EVP_MD_CTX *ctx, const void *data,
492                               size_t count)
493 {
494     return SHA1_Update(data(ctx), data, (size_t)count);
495 }
496 
497 static int digest_sha1_final(EVP_MD_CTX *ctx, unsigned char *md)
498 {
499     int ret;
500     ret = SHA1_Final(md, data(ctx));
501 
502     if (ret > 0) {
503         fill_known_data(md, SHA_DIGEST_LENGTH);
504     }
505     return ret;
506 }
507 
508 /*
509  * SHA256 implementation.
510  */
511 #undef data
512 #define data(ctx) ((SHA256_CTX *)EVP_MD_CTX_md_data(ctx))
513 static int digest_sha256_init(EVP_MD_CTX *ctx)
514 {
515     return SHA256_Init(data(ctx));
516 }
517 
518 static int digest_sha256_update(EVP_MD_CTX *ctx, const void *data,
519                                 size_t count)
520 {
521     return SHA256_Update(data(ctx), data, (size_t)count);
522 }
523 
524 static int digest_sha256_final(EVP_MD_CTX *ctx, unsigned char *md)
525 {
526     int ret;
527     ret = SHA256_Final(md, data(ctx));
528 
529     if (ret > 0) {
530         fill_known_data(md, SHA256_DIGEST_LENGTH);
531     }
532     return ret;
533 }
534 
535 /*
536  * SHA384/512 implementation.
537  */
538 #undef data
539 #define data(ctx) ((SHA512_CTX *)EVP_MD_CTX_md_data(ctx))
540 static int digest_sha384_init(EVP_MD_CTX *ctx)
541 {
542     return SHA384_Init(data(ctx));
543 }
544 
545 static int digest_sha512_init(EVP_MD_CTX *ctx)
546 {
547     return SHA512_Init(data(ctx));
548 }
549 
550 static int digest_sha512_update(EVP_MD_CTX *ctx, const void *data,
551                                 size_t count)
552 {
553     return SHA512_Update(data(ctx), data, (size_t)count);
554 }
555 
556 static int digest_sha384_final(EVP_MD_CTX *ctx, unsigned char *md)
557 {
558     int ret;
559     /* Actually uses SHA512_Final! */
560     ret = SHA512_Final(md, data(ctx));
561 
562     if (ret > 0) {
563         fill_known_data(md, SHA384_DIGEST_LENGTH);
564     }
565     return ret;
566 }
567 
568 static int digest_sha512_final(EVP_MD_CTX *ctx, unsigned char *md)
569 {
570     int ret;
571     ret = SHA512_Final(md, data(ctx));
572 
573     if (ret > 0) {
574         fill_known_data(md, SHA512_DIGEST_LENGTH);
575     }
576     return ret;
577 }
578 
579 /*
580  * AES128 Implementation
581  */
582 
583 int ossltest_aes128_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
584                              const unsigned char *iv, int enc)
585 {
586     return EVP_CIPHER_meth_get_init(EVP_aes_128_cbc()) (ctx, key, iv, enc);
587 }
588 
589 int ossltest_aes128_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
590                                const unsigned char *in, size_t inl)
591 {
592     unsigned char *tmpbuf;
593     int ret;
594 
595     tmpbuf = OPENSSL_malloc(inl);
596 
597     /* OPENSSL_malloc will return NULL if inl == 0 */
598     if (tmpbuf == NULL && inl > 0)
599         return -1;
600 
601     /* Remember what we were asked to encrypt */
602     if (tmpbuf != NULL)
603         memcpy(tmpbuf, in, inl);
604 
605     /* Go through the motions of encrypting it */
606     ret = EVP_CIPHER_meth_get_do_cipher(EVP_aes_128_cbc())(ctx, out, in, inl);
607 
608     /* Throw it all away and just use the plaintext as the output */
609     if (tmpbuf != NULL)
610         memcpy(out, tmpbuf, inl);
611     OPENSSL_free(tmpbuf);
612 
613     return ret;
614 }
615 
616 int ossltest_aes128_gcm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
617                              const unsigned char *iv, int enc)
618 {
619     return EVP_CIPHER_meth_get_init(EVP_aes_128_gcm()) (ctx, key, iv, enc);
620 }
621 
622 
623 int ossltest_aes128_gcm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
624                                const unsigned char *in, size_t inl)
625 {
626     unsigned char *tmpbuf = OPENSSL_malloc(inl);
627 
628     /* OPENSSL_malloc will return NULL if inl == 0 */
629     if (tmpbuf == NULL && inl > 0)
630         return -1;
631 
632     /* Remember what we were asked to encrypt */
633     if (tmpbuf != NULL)
634         memcpy(tmpbuf, in, inl);
635 
636     /* Go through the motions of encrypting it */
637     EVP_CIPHER_meth_get_do_cipher(EVP_aes_128_gcm())(ctx, out, in, inl);
638 
639     /* Throw it all away and just use the plaintext as the output */
640     if (tmpbuf != NULL && out != NULL)
641         memcpy(out, tmpbuf, inl);
642     OPENSSL_free(tmpbuf);
643 
644     return inl;
645 }
646 
647 static int ossltest_aes128_gcm_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
648                                     void *ptr)
649 {
650     /* Pass the ctrl down */
651     int ret = EVP_CIPHER_meth_get_ctrl(EVP_aes_128_gcm())(ctx, type, arg, ptr);
652 
653     if (ret <= 0)
654         return ret;
655 
656     switch(type) {
657     case EVP_CTRL_AEAD_GET_TAG:
658         /* Always give the same tag */
659         memset(ptr, 0, EVP_GCM_TLS_TAG_LEN);
660         break;
661 
662     default:
663         break;
664     }
665 
666     return 1;
667 }
668 
669 static int ossltest_rand_bytes(unsigned char *buf, int num)
670 {
671     unsigned char val = 1;
672 
673     while (--num >= 0)
674         *buf++ = val++;
675     return 1;
676 }
677 
678 static int ossltest_rand_status(void)
679 {
680     return 1;
681 }
682 
683 static const RAND_METHOD *ossltest_rand_method(void)
684 {
685 
686     static RAND_METHOD osslt_rand_meth = {
687         NULL,
688         ossltest_rand_bytes,
689         NULL,
690         NULL,
691         ossltest_rand_bytes,
692         ossltest_rand_status
693     };
694 
695     return &osslt_rand_meth;
696 }
697