xref: /illumos-gate/usr/src/lib/pkcs11/pkcs11_kernel/common/kernelDecrypt.c (revision 2aeafac3612e19716bf8164f89c3c9196342979c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  * Copyright 2018, Joyent, Inc.
25  */
26 
27 #include <pthread.h>
28 #include <stdlib.h>
29 #include <errno.h>
30 #include <sys/crypto/ioctl.h>
31 #include <security/cryptoki.h>
32 #include "kernelGlobal.h"
33 #include "kernelSession.h"
34 #include "kernelObject.h"
35 
36 
37 /*
38  * Real decryptInit work. The caller doesn't hold the session lock.
39  */
40 CK_RV
41 kernel_decrypt_init(kernel_session_t *session_p, kernel_object_t *key_p,
42     CK_MECHANISM_PTR pMechanism)
43 {
44 	CK_RV rv;
45 	crypto_decrypt_init_t decrypt_init;
46 	crypto_mech_type_t k_mech_type;
47 	boolean_t ses_lock_held = B_FALSE;
48 	int r;
49 	CK_AES_CCM_PARAMS ccm_params = { 0 };
50 
51 	/* Check to see if key object allows for decryption. */
52 	if (key_p->is_lib_obj && !(key_p->bool_attr_mask & DECRYPT_BOOL_ON)) {
53 		return (CKR_KEY_TYPE_INCONSISTENT);
54 	}
55 
56 	/* Get the kernel's internal mechanism number. */
57 	rv = kernel_mech(pMechanism->mechanism, &k_mech_type);
58 	if (rv != CKR_OK)
59 		return (rv);
60 
61 	(void) pthread_mutex_lock(&session_p->session_mutex);
62 	ses_lock_held = B_TRUE;
63 
64 	/*
65 	 * This active flag will remain ON until application calls either
66 	 * C_Decrypt or C_DecryptFinal to actually obtain the final piece
67 	 * of plaintext.
68 	 */
69 	session_p->decrypt.flags = CRYPTO_OPERATION_ACTIVE;
70 
71 	/* set up key data */
72 	if (!key_p->is_lib_obj) {
73 		decrypt_init.di_key.ck_format = CRYPTO_KEY_REFERENCE;
74 		decrypt_init.di_key.ck_obj_id = key_p->k_handle;
75 	} else {
76 		if (key_p->class == CKO_SECRET_KEY) {
77 			decrypt_init.di_key.ck_format = CRYPTO_KEY_RAW;
78 			decrypt_init.di_key.ck_data =
79 			    get_symmetric_key_value(key_p);
80 			if (decrypt_init.di_key.ck_data == NULL) {
81 				rv = CKR_HOST_MEMORY;
82 				goto clean_exit;
83 			}
84 			/* KEF key lengths are expressed in bits */
85 			decrypt_init.di_key.ck_length =
86 			    OBJ_SEC(key_p)->sk_value_len << 3;
87 
88 		} else if (key_p->key_type == CKK_RSA) {
89 			if (get_rsa_private_key(key_p, &decrypt_init.di_key) !=
90 			    CKR_OK) {
91 				rv = CKR_HOST_MEMORY;
92 				goto clean_exit;
93 			}
94 		} else {
95 			rv = CKR_KEY_TYPE_INCONSISTENT;
96 			goto clean_exit;
97 		}
98 	}
99 
100 	decrypt_init.di_session = session_p->k_session;
101 	session_p->decrypt.mech = *pMechanism;
102 
103 	/* Cache this capability value for efficiency */
104 	if (INPLACE_MECHANISM(session_p->decrypt.mech.mechanism)) {
105 		session_p->decrypt.flags |= CRYPTO_OPERATION_INPLACE_OK;
106 	}
107 	(void) pthread_mutex_unlock(&session_p->session_mutex);
108 
109 	ses_lock_held = B_FALSE;
110 	decrypt_init.di_mech.cm_type = k_mech_type;
111 	decrypt_init.di_mech.cm_param = pMechanism->pParameter;
112 	decrypt_init.di_mech.cm_param_len = pMechanism->ulParameterLen;
113 
114 	/*
115 	 * PKCS#11 uses CK_CCM_PARAMS as its mechanism parameter, while the
116 	 * kernel uses CK_AES_CCM_PARAMS.  Unlike
117 	 * CK_GCM_PARAMS / CK_AES_GCM_PARAMS, the two definitions are not
118 	 * equivalent -- the fields are defined in different orders, so
119 	 * we must translate.
120 	 */
121 	if (session_p->decrypt.mech.mechanism == CKM_AES_CCM) {
122 		if (pMechanism->ulParameterLen != sizeof (CK_CCM_PARAMS)) {
123 			rv = CKR_MECHANISM_PARAM_INVALID;
124 			goto clean_exit;
125 		}
126 		p11_to_kernel_ccm_params(pMechanism->pParameter, &ccm_params);
127 		decrypt_init.di_mech.cm_param = (caddr_t)&ccm_params;
128 		decrypt_init.di_mech.cm_param_len = sizeof (ccm_params);
129 	}
130 
131 	while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_INIT, &decrypt_init)) < 0) {
132 		if (errno != EINTR)
133 			break;
134 	}
135 	if (r < 0) {
136 		rv = CKR_FUNCTION_FAILED;
137 	} else {
138 		rv = crypto2pkcs11_error_number(decrypt_init.di_return_value);
139 	}
140 
141 	/* Free memory allocated for decrypt_init.di_key */
142 	if (key_p->is_lib_obj) {
143 		if (key_p->class == CKO_SECRET_KEY) {
144 			free(decrypt_init.di_key.ck_data);
145 		} else if (key_p->key_type == CKK_RSA) {
146 			free_key_attributes(&decrypt_init.di_key);
147 		}
148 	}
149 
150 clean_exit:
151 	/*
152 	 * ccm_params does not contain any key material -- just lengths and
153 	 * pointers, therefore it does not need to be zeroed on exit.
154 	 */
155 	if (!ses_lock_held) {
156 		(void) pthread_mutex_lock(&session_p->session_mutex);
157 		ses_lock_held = B_TRUE;
158 	}
159 
160 	if (rv != CKR_OK)
161 		session_p->decrypt.flags &= ~CRYPTO_OPERATION_ACTIVE;
162 
163 	if (ses_lock_held) {
164 		(void) pthread_mutex_unlock(&session_p->session_mutex);
165 		ses_lock_held = B_FALSE;
166 	}
167 
168 	return (rv);
169 }
170 
171 CK_RV
172 C_DecryptInit(CK_SESSION_HANDLE hSession, CK_MECHANISM_PTR pMechanism,
173     CK_OBJECT_HANDLE hKey)
174 {
175 
176 	CK_RV rv;
177 	kernel_session_t *session_p;
178 	kernel_object_t	*key_p;
179 	boolean_t ses_lock_held = B_FALSE;
180 
181 	if (!kernel_initialized)
182 		return (CKR_CRYPTOKI_NOT_INITIALIZED);
183 
184 	if (pMechanism == NULL) {
185 		return (CKR_ARGUMENTS_BAD);
186 	}
187 
188 	/* Obtain the session pointer. */
189 	rv = handle2session(hSession, &session_p);
190 	if (rv != CKR_OK)
191 		return (rv);
192 
193 	/* Obtain the object pointer. */
194 	HANDLE2OBJECT(hKey, key_p, rv);
195 	if (rv == CKR_OK) {
196 		rv = kernel_decrypt_init(session_p, key_p, pMechanism);
197 		OBJ_REFRELE(key_p);
198 	}
199 
200 	REFRELE(session_p, ses_lock_held);
201 	return (rv);
202 }
203 
204 
205 
206 /*
207  * Real decrypt work. The caller doesn't hold the session lock.
208  */
209 CK_RV
210 kernel_decrypt(kernel_session_t *session_p, CK_BYTE_PTR pEncryptedData,
211     CK_ULONG ulEncryptedData, CK_BYTE_PTR pData, CK_ULONG_PTR pulDataLen)
212 {
213 	crypto_decrypt_t decrypt;
214 	boolean_t ses_lock_held = B_FALSE;
215 	boolean_t inplace;
216 	CK_RV rv;
217 	int r;
218 
219 	(void) pthread_mutex_lock(&session_p->session_mutex);
220 	ses_lock_held = B_TRUE;
221 
222 	/* Application must call C_DecryptInit before calling C_Decrypt. */
223 	if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
224 		rv = CKR_OPERATION_NOT_INITIALIZED;
225 		goto clean_exit;
226 	}
227 
228 	/*
229 	 * C_Decrypt must be called without intervening C_DecryptUpdate
230 	 * calls.
231 	 */
232 	if (session_p->decrypt.flags & CRYPTO_OPERATION_UPDATE) {
233 		/*
234 		 * C_Decrypt cannot be used to terminate a multiple-part
235 		 * operation, so we'll leave the active decrypt operation
236 		 * flag on and let the application continue with the
237 		 * decrypt update operation.
238 		 */
239 		rv = CKR_FUNCTION_FAILED;
240 		goto clean_exit;
241 	}
242 
243 	decrypt.cd_session = session_p->k_session;
244 
245 	/*
246 	 * Certain mechanisms, where the length of the plaintext is
247 	 * same as the transformed ciphertext, can be optimized
248 	 * by the kernel into an in-place operation. Unfortunately,
249 	 * some applications use a plaintext buffer that is larger
250 	 * than it needs to be. We fix that here.
251 	 */
252 	inplace = (session_p->decrypt.flags & CRYPTO_OPERATION_INPLACE_OK) != 0;
253 
254 	if (ulEncryptedData < *pulDataLen && inplace) {
255 		decrypt.cd_datalen = ulEncryptedData;
256 	} else {
257 		decrypt.cd_datalen = *pulDataLen;
258 	}
259 	(void) pthread_mutex_unlock(&session_p->session_mutex);
260 	ses_lock_held = B_FALSE;
261 
262 	decrypt.cd_databuf = (char *)pData;
263 	decrypt.cd_encrlen = ulEncryptedData;
264 	decrypt.cd_encrbuf = (char *)pEncryptedData;
265 	decrypt.cd_flags =
266 	    ((inplace && (pData != NULL)) || (pData == pEncryptedData)) &&
267 	    (decrypt.cd_datalen == decrypt.cd_encrlen) ?
268 	    CRYPTO_INPLACE_OPERATION : 0;
269 
270 	while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT, &decrypt)) < 0) {
271 		if (errno != EINTR)
272 			break;
273 	}
274 	if (r < 0) {
275 		rv = CKR_FUNCTION_FAILED;
276 	} else {
277 		rv = crypto2pkcs11_error_number(decrypt.cd_return_value);
278 	}
279 
280 	if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL)
281 		*pulDataLen = decrypt.cd_datalen;
282 
283 clean_exit:
284 
285 	if (ses_lock_held)
286 		(void) pthread_mutex_unlock(&session_p->session_mutex);
287 
288 	return (rv);
289 }
290 
291 CK_RV
292 C_Decrypt(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pEncryptedData,
293     CK_ULONG ulEncryptedData, CK_BYTE_PTR pData, CK_ULONG_PTR pulDataLen)
294 {
295 	CK_RV rv;
296 	kernel_session_t *session_p;
297 	boolean_t ses_lock_held = B_FALSE;
298 
299 	if (!kernel_initialized)
300 		return (CKR_CRYPTOKI_NOT_INITIALIZED);
301 
302 	/* Obtain the session pointer. */
303 	rv = handle2session(hSession, &session_p);
304 	if (rv != CKR_OK)
305 		return (rv);
306 
307 	/*
308 	 * No need to check pData because application might
309 	 * just want to know the length of decrypted data.
310 	 */
311 	if (pulDataLen == NULL) {
312 		rv = CKR_ARGUMENTS_BAD;
313 		goto clean_exit;
314 	}
315 
316 	rv = kernel_decrypt(session_p, pEncryptedData, ulEncryptedData, pData,
317 	    pulDataLen);
318 
319 	if ((rv == CKR_BUFFER_TOO_SMALL) ||
320 	    (rv == CKR_OK && pData == NULL)) {
321 		/*
322 		 * We will not terminate the active decrypt operation flag,
323 		 * when the application-supplied buffer is too small, or
324 		 * the application asks for the length of buffer to hold
325 		 * the plaintext.
326 		 */
327 		REFRELE(session_p, ses_lock_held);
328 		return (rv);
329 	}
330 
331 clean_exit:
332 	/*
333 	 * Terminates the active decrypt operation.
334 	 * Application needs to call C_DecryptInit again for next
335 	 * decrypt operation.
336 	 */
337 	(void) pthread_mutex_lock(&session_p->session_mutex);
338 	session_p->decrypt.flags = 0;
339 	ses_lock_held = B_TRUE;
340 	REFRELE(session_p, ses_lock_held);
341 
342 	return (rv);
343 }
344 
345 
346 CK_RV
347 C_DecryptUpdate(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pEncryptedPart,
348     CK_ULONG ulEncryptedPartLen, CK_BYTE_PTR pPart,
349     CK_ULONG_PTR pulPartLen)
350 {
351 
352 	CK_RV rv;
353 	kernel_session_t *session_p;
354 	boolean_t ses_lock_held = B_FALSE;
355 	boolean_t inplace;
356 	crypto_decrypt_update_t decrypt_update;
357 	int r;
358 
359 	if (!kernel_initialized)
360 		return (CKR_CRYPTOKI_NOT_INITIALIZED);
361 
362 	/* Obtain the session pointer. */
363 	rv = handle2session(hSession, &session_p);
364 	if (rv != CKR_OK)
365 		return (rv);
366 
367 	if (pEncryptedPart == NULL) {
368 		rv = CKR_ARGUMENTS_BAD;
369 		goto clean_exit;
370 	}
371 
372 	/*
373 	 * Only check if pulPartLen is NULL.
374 	 * No need to check if pPart is NULL because application
375 	 * might just ask for the length of buffer to hold the
376 	 * recovered data.
377 	 */
378 	if (pulPartLen == NULL) {
379 		rv = CKR_ARGUMENTS_BAD;
380 		goto clean_exit;
381 	}
382 
383 	(void) pthread_mutex_lock(&session_p->session_mutex);
384 	ses_lock_held = B_TRUE;
385 
386 	/*
387 	 * Application must call C_DecryptInit before calling
388 	 * C_DecryptUpdate.
389 	 */
390 	if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
391 		REFRELE(session_p, ses_lock_held);
392 		return (CKR_OPERATION_NOT_INITIALIZED);
393 	}
394 
395 	session_p->decrypt.flags |= CRYPTO_OPERATION_UPDATE;
396 
397 	decrypt_update.du_session = session_p->k_session;
398 	(void) pthread_mutex_unlock(&session_p->session_mutex);
399 	ses_lock_held = B_FALSE;
400 
401 	decrypt_update.du_datalen = *pulPartLen;
402 	decrypt_update.du_databuf = (char *)pPart;
403 	decrypt_update.du_encrlen = ulEncryptedPartLen;
404 	decrypt_update.du_encrbuf = (char *)pEncryptedPart;
405 
406 	inplace = (session_p->decrypt.flags & CRYPTO_OPERATION_INPLACE_OK) != 0;
407 	decrypt_update.du_flags =
408 	    ((inplace && (pPart != NULL)) || (pPart == pEncryptedPart)) &&
409 	    (decrypt_update.du_datalen == decrypt_update.du_encrlen) ?
410 	    CRYPTO_INPLACE_OPERATION : 0;
411 
412 	while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_UPDATE,
413 	    &decrypt_update)) < 0) {
414 		if (errno != EINTR)
415 			break;
416 	}
417 	if (r < 0) {
418 		rv = CKR_FUNCTION_FAILED;
419 	} else {
420 		rv = crypto2pkcs11_error_number(
421 		    decrypt_update.du_return_value);
422 	}
423 
424 	/*
425 	 * If CKR_OK or CKR_BUFFER_TOO_SMALL, set the output length.
426 	 * We don't terminate the current decryption operation.
427 	 */
428 	if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL) {
429 		*pulPartLen = decrypt_update.du_datalen;
430 		REFRELE(session_p, ses_lock_held);
431 		return (rv);
432 	}
433 
434 clean_exit:
435 	/*
436 	 * After an error occurred, terminate the current decrypt
437 	 * operation by resetting the active and update flags.
438 	 */
439 	(void) pthread_mutex_lock(&session_p->session_mutex);
440 	session_p->decrypt.flags = 0;
441 	ses_lock_held = B_TRUE;
442 	REFRELE(session_p, ses_lock_held);
443 
444 	return (rv);
445 }
446 
447 
448 CK_RV
449 C_DecryptFinal(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pLastPart,
450     CK_ULONG_PTR pulLastPartLen)
451 {
452 
453 	CK_RV rv;
454 	kernel_session_t *session_p;
455 	boolean_t ses_lock_held = B_FALSE;
456 	crypto_decrypt_final_t decrypt_final;
457 	int r;
458 
459 	if (!kernel_initialized)
460 		return (CKR_CRYPTOKI_NOT_INITIALIZED);
461 
462 	/* Obtain the session pointer. */
463 	rv = handle2session(hSession, &session_p);
464 	if (rv != CKR_OK)
465 		return (rv);
466 
467 	if (pulLastPartLen == NULL) {
468 		rv = CKR_ARGUMENTS_BAD;
469 		goto clean_exit;
470 	}
471 
472 	(void) pthread_mutex_lock(&session_p->session_mutex);
473 	ses_lock_held = B_TRUE;
474 
475 	/*
476 	 * Application must call C_DecryptInit before calling
477 	 * C_DecryptFinal.
478 	 */
479 	if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
480 		REFRELE(session_p, ses_lock_held);
481 		return (CKR_OPERATION_NOT_INITIALIZED);
482 	}
483 
484 	decrypt_final.df_session = session_p->k_session;
485 	(void) pthread_mutex_unlock(&session_p->session_mutex);
486 	ses_lock_held = B_FALSE;
487 
488 	decrypt_final.df_datalen = *pulLastPartLen;
489 	decrypt_final.df_databuf = (char *)pLastPart;
490 
491 	while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_FINAL,
492 	    &decrypt_final)) < 0) {
493 		if (errno != EINTR)
494 			break;
495 	}
496 	if (r < 0) {
497 		rv = CKR_FUNCTION_FAILED;
498 	} else {
499 		rv = crypto2pkcs11_error_number(decrypt_final.df_return_value);
500 	}
501 
502 	if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL)
503 		*pulLastPartLen = decrypt_final.df_datalen;
504 
505 	if (rv == CKR_BUFFER_TOO_SMALL ||
506 	    (rv == CKR_OK && pLastPart == NULL)) {
507 		/*
508 		 * We will not terminate the active decrypt operation flag,
509 		 * when the application-supplied buffer is too small, or
510 		 * the application asks for the length of buffer to hold
511 		 * the plaintext.
512 		 */
513 		REFRELE(session_p, ses_lock_held);
514 		return (rv);
515 	}
516 
517 clean_exit:
518 	/* Terminates the active decrypt operation */
519 	(void) pthread_mutex_lock(&session_p->session_mutex);
520 	session_p->decrypt.flags = 0;
521 	ses_lock_held = B_TRUE;
522 	REFRELE(session_p, ses_lock_held);
523 
524 	return (rv);
525 }
526