1 /* SPDX-License-Identifier: BSD-2-Clause */
2 /*******************************************************************************
3  * Copyright 2017-2018, Fraunhofer SIT sponsored by Infineon Technologies AG
4  * All rights reserved.
5  ******************************************************************************/
6 
7 #ifdef HAVE_CONFIG_H
8 #include <config.h>
9 #endif
10 
11 #include "tss2_mu.h"
12 #include "tss2_sys.h"
13 #include "tss2_esys.h"
14 
15 #include "esys_types.h"
16 #include "esys_iutil.h"
17 #include "esys_mu.h"
18 #define LOGMODULE esys
19 #include "util/log.h"
20 #include "util/aux_util.h"
21 
22 /** One-Call function for TPM2_NV_Read
23  *
24  * This function invokes the TPM2_NV_Read command in a one-call
25  * variant. This means the function will block until the TPM response is
26  * available. All input parameters are const. The memory for non-simple output
27  * parameters is allocated by the function implementation.
28  *
29  * @param[in,out] esysContext The ESYS_CONTEXT.
30  * @param[in]  authHandle The handle indicating the source of the authorization
31  *             value.
32  * @param[in]  nvIndex The NV Index to be read.
33  * @param[in]  shandle1 Session handle for authorization of authHandle
34  * @param[in]  shandle2 Second session handle.
35  * @param[in]  shandle3 Third session handle.
36  * @param[in]  size Number of octets to read.
37  * @param[in]  offset Octet offset into the area.
38  * @param[out] data The data read.
39  *             (callee-allocated)
40  * @retval TSS2_RC_SUCCESS if the function call was a success.
41  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
42  *         pointers or required output handle references are NULL.
43  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
44  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
45  *         internal operations or return parameters.
46  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
47  *         operation already pending.
48  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
49  *          at least contain the tag, response length, and response code.
50  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
51  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
52            did not verify.
53  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
54  *         the 'decrypt' attribute bit set.
55  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
56  *         the 'encrypt' attribute bit set.
57  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
58  *         to the ESYS_CONTEXT or are of the wrong type or if required
59  *         ESYS_TR objects are ESYS_TR_NONE.
60  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
61  *         'decrypt' attribute set and the command does not support encryption
62  *         of the first command parameter.
63  * @retval TSS2_RCs produced by lower layers of the software stack may be
64  *         returned to the caller unaltered unless handled internally.
65  */
66 TSS2_RC
Esys_NV_Read(ESYS_CONTEXT * esysContext,ESYS_TR authHandle,ESYS_TR nvIndex,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,UINT16 size,UINT16 offset,TPM2B_MAX_NV_BUFFER ** data)67 Esys_NV_Read(
68     ESYS_CONTEXT *esysContext,
69     ESYS_TR authHandle,
70     ESYS_TR nvIndex,
71     ESYS_TR shandle1,
72     ESYS_TR shandle2,
73     ESYS_TR shandle3,
74     UINT16 size,
75     UINT16 offset,
76     TPM2B_MAX_NV_BUFFER **data)
77 {
78     TSS2_RC r;
79 
80     r = Esys_NV_Read_Async(esysContext, authHandle, nvIndex, shandle1, shandle2,
81                            shandle3, size, offset);
82     return_if_error(r, "Error in async function");
83 
84     /* Set the timeout to indefinite for now, since we want _Finish to block */
85     int32_t timeouttmp = esysContext->timeout;
86     esysContext->timeout = -1;
87     /*
88      * Now we call the finish function, until return code is not equal to
89      * from TSS2_BASE_RC_TRY_AGAIN.
90      * Note that the finish function may return TSS2_RC_TRY_AGAIN, even if we
91      * have set the timeout to -1. This occurs for example if the TPM requests
92      * a retransmission of the command via TPM2_RC_YIELDED.
93      */
94     do {
95         r = Esys_NV_Read_Finish(esysContext, data);
96         /* This is just debug information about the reattempt to finish the
97            command */
98         if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN)
99             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
100                       " => resubmitting command", r);
101     } while (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN);
102 
103     /* Restore the timeout value to the original value */
104     esysContext->timeout = timeouttmp;
105     return_if_error(r, "Esys Finish");
106 
107     return TSS2_RC_SUCCESS;
108 }
109 
110 /** Asynchronous function for TPM2_NV_Read
111  *
112  * This function invokes the TPM2_NV_Read command in a asynchronous
113  * variant. This means the function will return as soon as the command has been
114  * sent downwards the stack to the TPM. All input parameters are const.
115  * In order to retrieve the TPM's response call Esys_NV_Read_Finish.
116  *
117  * @param[in,out] esysContext The ESYS_CONTEXT.
118  * @param[in]  authHandle The handle indicating the source of the authorization
119  *             value.
120  * @param[in]  nvIndex The NV Index to be read.
121  * @param[in]  shandle1 Session handle for authorization of authHandle
122  * @param[in]  shandle2 Second session handle.
123  * @param[in]  shandle3 Third session handle.
124  * @param[in]  size Number of octets to read.
125  * @param[in]  offset Octet offset into the area.
126  * @retval ESYS_RC_SUCCESS if the function call was a success.
127  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
128  *         pointers or required output handle references are NULL.
129  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
130  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
131  *         internal operations or return parameters.
132  * @retval TSS2_RCs produced by lower layers of the software stack may be
133            returned to the caller unaltered unless handled internally.
134  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
135  *         the 'decrypt' attribute bit set.
136  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
137  *         the 'encrypt' attribute bit set.
138  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
139  *         to the ESYS_CONTEXT or are of the wrong type or if required
140  *         ESYS_TR objects are ESYS_TR_NONE.
141  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
142  *         'decrypt' attribute set and the command does not support encryption
143  *         of the first command parameter.
144  */
145 TSS2_RC
Esys_NV_Read_Async(ESYS_CONTEXT * esysContext,ESYS_TR authHandle,ESYS_TR nvIndex,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,UINT16 size,UINT16 offset)146 Esys_NV_Read_Async(
147     ESYS_CONTEXT *esysContext,
148     ESYS_TR authHandle,
149     ESYS_TR nvIndex,
150     ESYS_TR shandle1,
151     ESYS_TR shandle2,
152     ESYS_TR shandle3,
153     UINT16 size,
154     UINT16 offset)
155 {
156     TSS2_RC r;
157     LOG_TRACE("context=%p, authHandle=%"PRIx32 ", nvIndex=%"PRIx32 ","
158               "size=%04"PRIx16", offset=%04"PRIx16"",
159               esysContext, authHandle, nvIndex, size, offset);
160     TSS2L_SYS_AUTH_COMMAND auths;
161     RSRC_NODE_T *authHandleNode;
162     RSRC_NODE_T *nvIndexNode;
163 
164     /* Check context, sequence correctness and set state to error for now */
165     if (esysContext == NULL) {
166         LOG_ERROR("esyscontext is NULL.");
167         return TSS2_ESYS_RC_BAD_REFERENCE;
168     }
169     r = iesys_check_sequence_async(esysContext);
170     if (r != TSS2_RC_SUCCESS)
171         return r;
172     esysContext->state = _ESYS_STATE_INTERNALERROR;
173 
174     /* Check input parameters */
175     r = check_session_feasibility(shandle1, shandle2, shandle3, 1);
176     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
177 
178     /* Retrieve the metadata objects for provided handles */
179     r = esys_GetResourceObject(esysContext, authHandle, &authHandleNode);
180     return_state_if_error(r, _ESYS_STATE_INIT, "authHandle unknown.");
181     r = esys_GetResourceObject(esysContext, nvIndex, &nvIndexNode);
182     return_state_if_error(r, _ESYS_STATE_INIT, "nvIndex unknown.");
183 
184     /* Initial invocation of SAPI to prepare the command buffer with parameters */
185     r = Tss2_Sys_NV_Read_Prepare(esysContext->sys,
186                                  (authHandleNode == NULL) ? TPM2_RH_NULL
187                                   : authHandleNode->rsrc.handle,
188                                  (nvIndexNode == NULL) ? TPM2_RH_NULL
189                                   : nvIndexNode->rsrc.handle, size, offset);
190     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
191 
192     /* Calculate the cpHash Values */
193     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
194     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
195     if (authHandleNode != NULL)
196         iesys_compute_session_value(esysContext->session_tab[0],
197                 &authHandleNode->rsrc.name, &authHandleNode->auth);
198     else
199         iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
200 
201     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
202     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
203 
204     /* Generate the auth values and set them in the SAPI command buffer */
205     r = iesys_gen_auths(esysContext, authHandleNode, nvIndexNode, NULL, &auths);
206     return_state_if_error(r, _ESYS_STATE_INIT,
207                           "Error in computation of auth values");
208 
209     esysContext->authsCount = auths.count;
210     if (auths.count > 0) {
211         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
212         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
213     }
214 
215     /* Trigger execution and finish the async invocation */
216     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
217     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
218                           "Finish (Execute Async)");
219 
220     esysContext->state = _ESYS_STATE_SENT;
221 
222     return r;
223 }
224 
225 /** Asynchronous finish function for TPM2_NV_Read
226  *
227  * This function returns the results of a TPM2_NV_Read command
228  * invoked via Esys_NV_Read_Finish. All non-simple output parameters
229  * are allocated by the function's implementation. NULL can be passed for every
230  * output parameter if the value is not required.
231  *
232  * @param[in,out] esysContext The ESYS_CONTEXT.
233  * @param[out] data The data read.
234  *             (callee-allocated)
235  * @retval TSS2_RC_SUCCESS on success
236  * @retval ESYS_RC_SUCCESS if the function call was a success.
237  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
238  *         pointers or required output handle references are NULL.
239  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
240  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
241  *         internal operations or return parameters.
242  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
243  *         operation already pending.
244  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
245  *         TPM response is received.
246  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
247  *         at least contain the tag, response length, and response code.
248  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
249  *         not verify.
250  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
251  * @retval TSS2_RCs produced by lower layers of the software stack may be
252  *         returned to the caller unaltered unless handled internally.
253  */
254 TSS2_RC
Esys_NV_Read_Finish(ESYS_CONTEXT * esysContext,TPM2B_MAX_NV_BUFFER ** data)255 Esys_NV_Read_Finish(
256     ESYS_CONTEXT *esysContext,
257     TPM2B_MAX_NV_BUFFER **data)
258 {
259     TSS2_RC r;
260     LOG_TRACE("context=%p, data=%p",
261               esysContext, data);
262 
263     if (esysContext == NULL) {
264         LOG_ERROR("esyscontext is NULL.");
265         return TSS2_ESYS_RC_BAD_REFERENCE;
266     }
267 
268     /* Check for correct sequence and set sequence to irregular for now */
269     if (esysContext->state != _ESYS_STATE_SENT &&
270         esysContext->state != _ESYS_STATE_RESUBMISSION) {
271         LOG_ERROR("Esys called in bad sequence.");
272         return TSS2_ESYS_RC_BAD_SEQUENCE;
273     }
274     esysContext->state = _ESYS_STATE_INTERNALERROR;
275 
276     /* Allocate memory for response parameters */
277     if (data != NULL) {
278         *data = calloc(sizeof(TPM2B_MAX_NV_BUFFER), 1);
279         if (*data == NULL) {
280             return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
281         }
282     }
283 
284     /*Receive the TPM response and handle resubmissions if necessary. */
285     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
286     if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN) {
287         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
288         esysContext->state = _ESYS_STATE_SENT;
289         goto error_cleanup;
290     }
291     /* This block handle the resubmission of TPM commands given a certain set of
292      * TPM response codes. */
293     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
294         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
295             "resubmission: %" PRIx32, r);
296         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
297             LOG_WARNING("Maximum number of (re)submissions has been reached.");
298             esysContext->state = _ESYS_STATE_INIT;
299             goto error_cleanup;
300         }
301         esysContext->state = _ESYS_STATE_RESUBMISSION;
302         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
303         if (r != TSS2_RC_SUCCESS) {
304             LOG_WARNING("Error attempting to resubmit");
305             /* We do not set esysContext->state here but inherit the most recent
306              * state of the _async function. */
307             goto error_cleanup;
308         }
309         r = TSS2_ESYS_RC_TRY_AGAIN;
310         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
311         goto error_cleanup;
312     }
313     /* The following is the "regular error" handling. */
314     if (iesys_tpm_error(r)) {
315         LOG_WARNING("Received TPM Error");
316         esysContext->state = _ESYS_STATE_INIT;
317         goto error_cleanup;
318     } else if (r != TSS2_RC_SUCCESS) {
319         LOG_ERROR("Received a non-TPM Error");
320         esysContext->state = _ESYS_STATE_INTERNALERROR;
321         goto error_cleanup;
322     }
323 
324     /*
325      * Now the verification of the response (hmac check) and if necessary the
326      * parameter decryption have to be done.
327      */
328     r = iesys_check_response(esysContext);
329     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
330                         error_cleanup);
331 
332     /*
333      * After the verification of the response we call the complete function
334      * to deliver the result.
335      */
336     r = Tss2_Sys_NV_Read_Complete(esysContext->sys,
337                                   (data != NULL) ? *data : NULL);
338     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
339                         "Received error from SAPI unmarshaling" ,
340                         error_cleanup);
341 
342     esysContext->state = _ESYS_STATE_INIT;
343 
344     return TSS2_RC_SUCCESS;
345 
346 error_cleanup:
347     if (data != NULL)
348         SAFE_FREE(*data);
349 
350     return r;
351 }
352