NetworkPkg/TlsDxe: verify DataSize for EfiTlsCipherList
[mirror_edk2.git] / NetworkPkg / TlsDxe / TlsProtocol.c
1 /** @file
2 Implementation of EFI TLS Protocol Interfaces.
3
4 Copyright (c) 2016 - 2017, Intel Corporation. All rights reserved.<BR>
5
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php.
10
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13
14 **/
15
16 #include "TlsImpl.h"
17
18 EFI_TLS_PROTOCOL mTlsProtocol = {
19 TlsSetSessionData,
20 TlsGetSessionData,
21 TlsBuildResponsePacket,
22 TlsProcessPacket
23 };
24
25 /**
26 Set TLS session data.
27
28 The SetSessionData() function set data for a new TLS session. All session data should
29 be set before BuildResponsePacket() invoked.
30
31 @param[in] This Pointer to the EFI_TLS_PROTOCOL instance.
32 @param[in] DataType TLS session data type.
33 @param[in] Data Pointer to session data.
34 @param[in] DataSize Total size of session data.
35
36 @retval EFI_SUCCESS The TLS session data is set successfully.
37 @retval EFI_INVALID_PARAMETER One or more of the following conditions is TRUE:
38 This is NULL.
39 Data is NULL.
40 DataSize is 0.
41 DataSize is invalid for DataType.
42 @retval EFI_UNSUPPORTED The DataType is unsupported.
43 @retval EFI_ACCESS_DENIED If the DataType is one of below:
44 EfiTlsClientRandom
45 EfiTlsServerRandom
46 EfiTlsKeyMaterial
47 @retval EFI_NOT_READY Current TLS session state is NOT
48 EfiTlsSessionStateNotStarted.
49 @retval EFI_OUT_OF_RESOURCES Required system resources could not be allocated.
50 **/
51 EFI_STATUS
52 EFIAPI
53 TlsSetSessionData (
54 IN EFI_TLS_PROTOCOL *This,
55 IN EFI_TLS_SESSION_DATA_TYPE DataType,
56 IN VOID *Data,
57 IN UINTN DataSize
58 )
59 {
60 EFI_STATUS Status;
61 TLS_INSTANCE *Instance;
62 UINT16 *CipherId;
63 UINTN CipherCount;
64 UINTN Index;
65
66 EFI_TPL OldTpl;
67
68 Status = EFI_SUCCESS;
69 CipherId = NULL;
70
71 if (This == NULL || Data == NULL || DataSize == 0) {
72 return EFI_INVALID_PARAMETER;
73 }
74
75 OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
76
77 Instance = TLS_INSTANCE_FROM_PROTOCOL (This);
78
79 if (DataType != EfiTlsSessionState && Instance->TlsSessionState != EfiTlsSessionNotStarted){
80 Status = EFI_NOT_READY;
81 goto ON_EXIT;
82 }
83
84 switch (DataType) {
85 //
86 // Session Configuration
87 //
88 case EfiTlsVersion:
89 if (DataSize != sizeof (EFI_TLS_VERSION)) {
90 Status = EFI_INVALID_PARAMETER;
91 goto ON_EXIT;
92 }
93
94 Status = TlsSetVersion (Instance->TlsConn, ((EFI_TLS_VERSION *) Data)->Major, ((EFI_TLS_VERSION *) Data)->Minor);
95 break;
96 case EfiTlsConnectionEnd:
97 if (DataSize != sizeof (EFI_TLS_CONNECTION_END)) {
98 Status = EFI_INVALID_PARAMETER;
99 goto ON_EXIT;
100 }
101
102 Status = TlsSetConnectionEnd (Instance->TlsConn, *((EFI_TLS_CONNECTION_END *) Data));
103 break;
104 case EfiTlsCipherList:
105 if (DataSize % sizeof (EFI_TLS_CIPHER) != 0) {
106 Status = EFI_INVALID_PARAMETER;
107 goto ON_EXIT;
108 }
109
110 CipherId = AllocatePool (DataSize);
111 if (CipherId == NULL) {
112 Status = EFI_OUT_OF_RESOURCES;
113 goto ON_EXIT;
114 }
115
116 CipherCount = DataSize / sizeof (EFI_TLS_CIPHER);
117 for (Index = 0; Index < CipherCount; Index++) {
118 *(CipherId +Index) = HTONS (*(((UINT16 *) Data) + Index));
119 }
120
121 Status = TlsSetCipherList (Instance->TlsConn, CipherId, CipherCount);
122
123 FreePool (CipherId);
124 break;
125 case EfiTlsCompressionMethod:
126 //
127 // TLS seems only define one CompressionMethod.null, which specifies that data exchanged via the
128 // record protocol will not be compressed.
129 // More information from OpenSSL: http://www.openssl.org/docs/manmaster/ssl/SSL_COMP_add_compression_method.html
130 // The TLS RFC does however not specify compression methods or their corresponding identifiers,
131 // so there is currently no compatible way to integrate compression with unknown peers.
132 // It is therefore currently not recommended to integrate compression into applications.
133 // Applications for non-public use may agree on certain compression methods.
134 // Using different compression methods with the same identifier will lead to connection failure.
135 //
136 for (Index = 0; Index < DataSize / sizeof (EFI_TLS_COMPRESSION); Index++) {
137 Status = TlsSetCompressionMethod (*((UINT8 *) Data + Index));
138 if (EFI_ERROR (Status)) {
139 break;
140 }
141 }
142
143 break;
144 case EfiTlsExtensionData:
145 Status = EFI_UNSUPPORTED;
146 goto ON_EXIT;
147 case EfiTlsVerifyMethod:
148 if (DataSize != sizeof (EFI_TLS_VERIFY)) {
149 Status = EFI_INVALID_PARAMETER;
150 goto ON_EXIT;
151 }
152
153 TlsSetVerify (Instance->TlsConn, *((UINT32 *) Data));
154 break;
155 case EfiTlsSessionID:
156 if (DataSize != sizeof (EFI_TLS_SESSION_ID)) {
157 Status = EFI_INVALID_PARAMETER;
158 goto ON_EXIT;
159 }
160
161 Status = TlsSetSessionId (
162 Instance->TlsConn,
163 ((EFI_TLS_SESSION_ID *) Data)->Data,
164 ((EFI_TLS_SESSION_ID *) Data)->Length
165 );
166 break;
167 case EfiTlsSessionState:
168 if (DataSize != sizeof (EFI_TLS_SESSION_STATE)) {
169 Status = EFI_INVALID_PARAMETER;
170 goto ON_EXIT;
171 }
172
173 Instance->TlsSessionState = *(EFI_TLS_SESSION_STATE *) Data;
174 break;
175 //
176 // Session information
177 //
178 case EfiTlsClientRandom:
179 Status = EFI_ACCESS_DENIED;
180 break;
181 case EfiTlsServerRandom:
182 Status = EFI_ACCESS_DENIED;
183 break;
184 case EfiTlsKeyMaterial:
185 Status = EFI_ACCESS_DENIED;
186 break;
187 //
188 // Unsupported type.
189 //
190 default:
191 Status = EFI_UNSUPPORTED;
192 }
193
194 ON_EXIT:
195 gBS->RestoreTPL (OldTpl);
196 return Status;
197 }
198
199 /**
200 Get TLS session data.
201
202 The GetSessionData() function return the TLS session information.
203
204 @param[in] This Pointer to the EFI_TLS_PROTOCOL instance.
205 @param[in] DataType TLS session data type.
206 @param[in, out] Data Pointer to session data.
207 @param[in, out] DataSize Total size of session data. On input, it means
208 the size of Data buffer. On output, it means the size
209 of copied Data buffer if EFI_SUCCESS, and means the
210 size of desired Data buffer if EFI_BUFFER_TOO_SMALL.
211
212 @retval EFI_SUCCESS The TLS session data is got successfully.
213 @retval EFI_INVALID_PARAMETER One or more of the following conditions is TRUE:
214 This is NULL.
215 DataSize is NULL.
216 Data is NULL if *DataSize is not zero.
217 @retval EFI_UNSUPPORTED The DataType is unsupported.
218 @retval EFI_NOT_FOUND The TLS session data is not found.
219 @retval EFI_NOT_READY The DataType is not ready in current session state.
220 @retval EFI_BUFFER_TOO_SMALL The buffer is too small to hold the data.
221 **/
222 EFI_STATUS
223 EFIAPI
224 TlsGetSessionData (
225 IN EFI_TLS_PROTOCOL *This,
226 IN EFI_TLS_SESSION_DATA_TYPE DataType,
227 IN OUT VOID *Data, OPTIONAL
228 IN OUT UINTN *DataSize
229 )
230 {
231 EFI_STATUS Status;
232 TLS_INSTANCE *Instance;
233
234 EFI_TPL OldTpl;
235
236 Status = EFI_SUCCESS;
237
238 if (This == NULL || DataSize == NULL || (Data == NULL && *DataSize != 0)) {
239 return EFI_INVALID_PARAMETER;
240 }
241
242 OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
243
244 Instance = TLS_INSTANCE_FROM_PROTOCOL (This);
245
246 if (Instance->TlsSessionState == EfiTlsSessionNotStarted &&
247 (DataType == EfiTlsSessionID || DataType == EfiTlsClientRandom ||
248 DataType == EfiTlsServerRandom || DataType == EfiTlsKeyMaterial)) {
249 Status = EFI_NOT_READY;
250 goto ON_EXIT;
251 }
252
253 switch (DataType) {
254 case EfiTlsVersion:
255 if (*DataSize < sizeof (EFI_TLS_VERSION)) {
256 *DataSize = sizeof (EFI_TLS_VERSION);
257 Status = EFI_BUFFER_TOO_SMALL;
258 goto ON_EXIT;
259 }
260 *DataSize = sizeof (EFI_TLS_VERSION);
261 *((UINT16 *) Data) = HTONS (TlsGetVersion (Instance->TlsConn));
262 break;
263 case EfiTlsConnectionEnd:
264 if (*DataSize < sizeof (EFI_TLS_CONNECTION_END)) {
265 *DataSize = sizeof (EFI_TLS_CONNECTION_END);
266 Status = EFI_BUFFER_TOO_SMALL;
267 goto ON_EXIT;
268 }
269 *DataSize = sizeof (EFI_TLS_CONNECTION_END);
270 *((UINT8 *) Data) = TlsGetConnectionEnd (Instance->TlsConn);
271 break;
272 case EfiTlsCipherList:
273 //
274 // Get the current session cipher suite.
275 //
276 if (*DataSize < sizeof (EFI_TLS_CIPHER)) {
277 *DataSize = sizeof (EFI_TLS_CIPHER);
278 Status = EFI_BUFFER_TOO_SMALL;
279 goto ON_EXIT;
280 }
281 *DataSize = sizeof(EFI_TLS_CIPHER);
282 Status = TlsGetCurrentCipher (Instance->TlsConn, (UINT16 *) Data);
283 *((UINT16 *) Data) = HTONS (*((UINT16 *) Data));
284 break;
285 case EfiTlsCompressionMethod:
286 //
287 // Get the current session compression method.
288 //
289 if (*DataSize < sizeof (EFI_TLS_COMPRESSION)) {
290 *DataSize = sizeof (EFI_TLS_COMPRESSION);
291 Status = EFI_BUFFER_TOO_SMALL;
292 goto ON_EXIT;
293 }
294 *DataSize = sizeof (EFI_TLS_COMPRESSION);
295 Status = TlsGetCurrentCompressionId (Instance->TlsConn, (UINT8 *) Data);
296 break;
297 case EfiTlsExtensionData:
298 Status = EFI_UNSUPPORTED;
299 goto ON_EXIT;
300 case EfiTlsVerifyMethod:
301 if (*DataSize < sizeof (EFI_TLS_VERIFY)) {
302 *DataSize = sizeof (EFI_TLS_VERIFY);
303 Status = EFI_BUFFER_TOO_SMALL;
304 goto ON_EXIT;
305 }
306 *DataSize = sizeof (EFI_TLS_VERIFY);
307 *((UINT32 *) Data) = TlsGetVerify (Instance->TlsConn);
308 break;
309 case EfiTlsSessionID:
310 if (*DataSize < sizeof (EFI_TLS_SESSION_ID)) {
311 *DataSize = sizeof (EFI_TLS_SESSION_ID);
312 Status = EFI_BUFFER_TOO_SMALL;
313 goto ON_EXIT;
314 }
315 *DataSize = sizeof (EFI_TLS_SESSION_ID);
316 Status = TlsGetSessionId (
317 Instance->TlsConn,
318 ((EFI_TLS_SESSION_ID *) Data)->Data,
319 &(((EFI_TLS_SESSION_ID *) Data)->Length)
320 );
321 break;
322 case EfiTlsSessionState:
323 if (*DataSize < sizeof (EFI_TLS_SESSION_STATE)) {
324 *DataSize = sizeof (EFI_TLS_SESSION_STATE);
325 Status = EFI_BUFFER_TOO_SMALL;
326 goto ON_EXIT;
327 }
328 *DataSize = sizeof (EFI_TLS_SESSION_STATE);
329 CopyMem (Data, &Instance->TlsSessionState, *DataSize);
330 break;
331 case EfiTlsClientRandom:
332 if (*DataSize < sizeof (EFI_TLS_RANDOM)) {
333 *DataSize = sizeof (EFI_TLS_RANDOM);
334 Status = EFI_BUFFER_TOO_SMALL;
335 goto ON_EXIT;
336 }
337 *DataSize = sizeof (EFI_TLS_RANDOM);
338 TlsGetClientRandom (Instance->TlsConn, (UINT8 *) Data);
339 break;
340 case EfiTlsServerRandom:
341 if (*DataSize < sizeof (EFI_TLS_RANDOM)) {
342 *DataSize = sizeof (EFI_TLS_RANDOM);
343 Status = EFI_BUFFER_TOO_SMALL;
344 goto ON_EXIT;
345 }
346 *DataSize = sizeof (EFI_TLS_RANDOM);
347 TlsGetServerRandom (Instance->TlsConn, (UINT8 *) Data);
348 break;
349 case EfiTlsKeyMaterial:
350 if (*DataSize < sizeof (EFI_TLS_MASTER_SECRET)) {
351 *DataSize = sizeof (EFI_TLS_MASTER_SECRET);
352 Status = EFI_BUFFER_TOO_SMALL;
353 goto ON_EXIT;
354 }
355 *DataSize = sizeof (EFI_TLS_MASTER_SECRET);
356 Status = TlsGetKeyMaterial (Instance->TlsConn, (UINT8 *) Data);
357 break;
358 //
359 // Unsupported type.
360 //
361 default:
362 Status = EFI_UNSUPPORTED;
363 }
364
365 ON_EXIT:
366 gBS->RestoreTPL (OldTpl);
367 return Status;
368 }
369
370 /**
371 Build response packet according to TLS state machine. This function is only valid for
372 alert, handshake and change_cipher_spec content type.
373
374 The BuildResponsePacket() function builds TLS response packet in response to the TLS
375 request packet specified by RequestBuffer and RequestSize. If RequestBuffer is NULL and
376 RequestSize is 0, and TLS session status is EfiTlsSessionNotStarted, the TLS session
377 will be initiated and the response packet needs to be ClientHello. If RequestBuffer is
378 NULL and RequestSize is 0, and TLS session status is EfiTlsSessionClosing, the TLS
379 session will be closed and response packet needs to be CloseNotify. If RequestBuffer is
380 NULL and RequestSize is 0, and TLS session status is EfiTlsSessionError, the TLS
381 session has errors and the response packet needs to be Alert message based on error
382 type.
383
384 @param[in] This Pointer to the EFI_TLS_PROTOCOL instance.
385 @param[in] RequestBuffer Pointer to the most recently received TLS packet. NULL
386 means TLS need initiate the TLS session and response
387 packet need to be ClientHello.
388 @param[in] RequestSize Packet size in bytes for the most recently received TLS
389 packet. 0 is only valid when RequestBuffer is NULL.
390 @param[out] Buffer Pointer to the buffer to hold the built packet.
391 @param[in, out] BufferSize Pointer to the buffer size in bytes. On input, it is
392 the buffer size provided by the caller. On output, it
393 is the buffer size in fact needed to contain the
394 packet.
395
396 @retval EFI_SUCCESS The required TLS packet is built successfully.
397 @retval EFI_INVALID_PARAMETER One or more of the following conditions is TRUE:
398 This is NULL.
399 RequestBuffer is NULL but RequestSize is NOT 0.
400 RequestSize is 0 but RequestBuffer is NOT NULL.
401 BufferSize is NULL.
402 Buffer is NULL if *BufferSize is not zero.
403 @retval EFI_BUFFER_TOO_SMALL BufferSize is too small to hold the response packet.
404 @retval EFI_NOT_READY Current TLS session state is NOT ready to build
405 ResponsePacket.
406 @retval EFI_ABORTED Something wrong build response packet.
407 **/
408 EFI_STATUS
409 EFIAPI
410 TlsBuildResponsePacket (
411 IN EFI_TLS_PROTOCOL *This,
412 IN UINT8 *RequestBuffer, OPTIONAL
413 IN UINTN RequestSize, OPTIONAL
414 OUT UINT8 *Buffer, OPTIONAL
415 IN OUT UINTN *BufferSize
416 )
417 {
418 EFI_STATUS Status;
419 TLS_INSTANCE *Instance;
420 EFI_TPL OldTpl;
421
422 Status = EFI_SUCCESS;
423
424 if ((This == NULL) || (BufferSize == NULL) ||
425 (RequestBuffer == NULL && RequestSize != 0) ||
426 (RequestBuffer != NULL && RequestSize == 0) ||
427 (Buffer == NULL && *BufferSize !=0)) {
428 return EFI_INVALID_PARAMETER;
429 }
430
431 OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
432
433 Instance = TLS_INSTANCE_FROM_PROTOCOL (This);
434
435 if(RequestBuffer == NULL && RequestSize == 0) {
436 switch (Instance->TlsSessionState) {
437 case EfiTlsSessionNotStarted:
438 //
439 // ClientHello.
440 //
441 Status = TlsDoHandshake (
442 Instance->TlsConn,
443 NULL,
444 0,
445 Buffer,
446 BufferSize
447 );
448 if (EFI_ERROR (Status)) {
449 goto ON_EXIT;
450 }
451
452 //
453 // *BufferSize should not be zero when ClientHello.
454 //
455 if (*BufferSize == 0) {
456 Status = EFI_ABORTED;
457 goto ON_EXIT;
458 }
459
460 Instance->TlsSessionState = EfiTlsSessionHandShaking;
461
462 break;
463 case EfiTlsSessionClosing:
464 //
465 // TLS session will be closed and response packet needs to be CloseNotify.
466 //
467 Status = TlsCloseNotify (
468 Instance->TlsConn,
469 Buffer,
470 BufferSize
471 );
472 if (EFI_ERROR (Status)) {
473 goto ON_EXIT;
474 }
475
476 //
477 // *BufferSize should not be zero when build CloseNotify message.
478 //
479 if (*BufferSize == 0) {
480 Status = EFI_ABORTED;
481 goto ON_EXIT;
482 }
483
484 break;
485 case EfiTlsSessionError:
486 //
487 // TLS session has errors and the response packet needs to be Alert
488 // message based on error type.
489 //
490 Status = TlsHandleAlert (
491 Instance->TlsConn,
492 NULL,
493 0,
494 Buffer,
495 BufferSize
496 );
497 if (EFI_ERROR (Status)) {
498 goto ON_EXIT;
499 }
500
501 break;
502 default:
503 //
504 // Current TLS session state is NOT ready to build ResponsePacket.
505 //
506 Status = EFI_NOT_READY;
507 }
508 } else {
509 //
510 // 1. Received packet may have multiple TLS record messages.
511 // 2. One TLS record message may have multiple handshake protocol.
512 // 3. Some errors may be happened in handshake.
513 // TlsDoHandshake() can handle all of those cases.
514 //
515 if (TlsInHandshake (Instance->TlsConn)) {
516 Status = TlsDoHandshake (
517 Instance->TlsConn,
518 RequestBuffer,
519 RequestSize,
520 Buffer,
521 BufferSize
522 );
523 if (EFI_ERROR (Status)) {
524 goto ON_EXIT;
525 }
526
527 if (!TlsInHandshake (Instance->TlsConn)) {
528 Instance->TlsSessionState = EfiTlsSessionDataTransferring;
529 }
530 } else {
531 //
532 // Must be alert message, Decrypt it and build the ResponsePacket.
533 //
534 ASSERT (((TLS_RECORD_HEADER *) RequestBuffer)->ContentType == TlsContentTypeAlert);
535
536 Status = TlsHandleAlert (
537 Instance->TlsConn,
538 RequestBuffer,
539 RequestSize,
540 Buffer,
541 BufferSize
542 );
543 if (EFI_ERROR (Status)) {
544 if (Status != EFI_BUFFER_TOO_SMALL) {
545 Instance->TlsSessionState = EfiTlsSessionError;
546 }
547
548 goto ON_EXIT;
549 }
550 }
551 }
552
553 ON_EXIT:
554 gBS->RestoreTPL (OldTpl);
555 return Status;
556 }
557
558 /**
559 Decrypt or encrypt TLS packet during session. This function is only valid after
560 session connected and for application_data content type.
561
562 The ProcessPacket () function process each inbound or outbound TLS APP packet.
563
564 @param[in] This Pointer to the EFI_TLS_PROTOCOL instance.
565 @param[in, out] FragmentTable Pointer to a list of fragment. The caller will take
566 responsible to handle the original FragmentTable while
567 it may be reallocated in TLS driver. If CryptMode is
568 EfiTlsEncrypt, on input these fragments contain the TLS
569 header and plain text TLS APP payload; on output these
570 fragments contain the TLS header and cipher text TLS
571 APP payload. If CryptMode is EfiTlsDecrypt, on input
572 these fragments contain the TLS header and cipher text
573 TLS APP payload; on output these fragments contain the
574 TLS header and plain text TLS APP payload.
575 @param[in] FragmentCount Number of fragment.
576 @param[in] CryptMode Crypt mode.
577
578 @retval EFI_SUCCESS The operation completed successfully.
579 @retval EFI_INVALID_PARAMETER One or more of the following conditions is TRUE:
580 This is NULL.
581 FragmentTable is NULL.
582 FragmentCount is NULL.
583 CryptoMode is invalid.
584 @retval EFI_NOT_READY Current TLS session state is NOT
585 EfiTlsSessionDataTransferring.
586 @retval EFI_ABORTED Something wrong decryption the message. TLS session
587 status will become EfiTlsSessionError. The caller need
588 call BuildResponsePacket() to generate Error Alert
589 message and send it out.
590 @retval EFI_OUT_OF_RESOURCES No enough resource to finish the operation.
591 **/
592 EFI_STATUS
593 EFIAPI
594 TlsProcessPacket (
595 IN EFI_TLS_PROTOCOL *This,
596 IN OUT EFI_TLS_FRAGMENT_DATA **FragmentTable,
597 IN UINT32 *FragmentCount,
598 IN EFI_TLS_CRYPT_MODE CryptMode
599 )
600 {
601 EFI_STATUS Status;
602 TLS_INSTANCE *Instance;
603
604 EFI_TPL OldTpl;
605
606 Status = EFI_SUCCESS;
607
608 if (This == NULL || FragmentTable == NULL || FragmentCount == NULL) {
609 return EFI_INVALID_PARAMETER;
610 }
611
612 OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
613
614 Instance = TLS_INSTANCE_FROM_PROTOCOL (This);
615
616 if (Instance->TlsSessionState != EfiTlsSessionDataTransferring) {
617 Status = EFI_NOT_READY;
618 goto ON_EXIT;
619 }
620
621 //
622 // Packet sent or received may have multiple TLS record messages (Application data type).
623 // So,on input these fragments contain the TLS header and TLS APP payload;
624 // on output these fragments also contain the TLS header and TLS APP payload.
625 //
626 switch (CryptMode) {
627 case EfiTlsEncrypt:
628 Status = TlsEncryptPacket (Instance, FragmentTable, FragmentCount);
629 break;
630 case EfiTlsDecrypt:
631 Status = TlsDecryptPacket (Instance, FragmentTable, FragmentCount);
632 break;
633 default:
634 return EFI_INVALID_PARAMETER;
635 }
636
637 ON_EXIT:
638 gBS->RestoreTPL (OldTpl);
639 return Status;
640 }
641