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_ReadClock
23  *
24  * This function invokes the TPM2_ReadClock 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]  shandle1 First session handle.
31  * @param[in]  shandle2 Second session handle.
32  * @param[in]  shandle3 Third session handle.
33  * @param[out] currentTime .
34  *             (callee-allocated)
35  * @retval TSS2_RC_SUCCESS if the function call was a success.
36  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
37  *         pointers or required output handle references are NULL.
38  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
39  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
40  *         internal operations or return parameters.
41  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
42  *         operation already pending.
43  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
44  *          at least contain the tag, response length, and response code.
45  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
46  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
47            did not verify.
48  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
49  *         the 'decrypt' attribute bit set.
50  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
51  *         the 'encrypt' attribute bit set.
52  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
53  *         'decrypt' attribute set and the command does not support encryption
54  *         of the first command parameter.
55  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
56  *         'encrypt' attribute set and the command does not support encryption
57  *          of the first response parameter.
58  * @retval TSS2_RCs produced by lower layers of the software stack may be
59  *         returned to the caller unaltered unless handled internally.
60  */
61 TSS2_RC
Esys_ReadClock(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,TPMS_TIME_INFO ** currentTime)62 Esys_ReadClock(
63     ESYS_CONTEXT *esysContext,
64     ESYS_TR shandle1,
65     ESYS_TR shandle2,
66     ESYS_TR shandle3,
67     TPMS_TIME_INFO **currentTime)
68 {
69     TSS2_RC r;
70 
71     r = Esys_ReadClock_Async(esysContext, shandle1, shandle2, shandle3);
72     return_if_error(r, "Error in async function");
73 
74     /* Set the timeout to indefinite for now, since we want _Finish to block */
75     int32_t timeouttmp = esysContext->timeout;
76     esysContext->timeout = -1;
77     /*
78      * Now we call the finish function, until return code is not equal to
79      * from TSS2_BASE_RC_TRY_AGAIN.
80      * Note that the finish function may return TSS2_RC_TRY_AGAIN, even if we
81      * have set the timeout to -1. This occurs for example if the TPM requests
82      * a retransmission of the command via TPM2_RC_YIELDED.
83      */
84     do {
85         r = Esys_ReadClock_Finish(esysContext, currentTime);
86         /* This is just debug information about the reattempt to finish the
87            command */
88         if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN)
89             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
90                       " => resubmitting command", r);
91     } while (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN);
92 
93     /* Restore the timeout value to the original value */
94     esysContext->timeout = timeouttmp;
95     return_if_error(r, "Esys Finish");
96 
97     return TSS2_RC_SUCCESS;
98 }
99 
100 /** Asynchronous function for TPM2_ReadClock
101  *
102  * This function invokes the TPM2_ReadClock command in a asynchronous
103  * variant. This means the function will return as soon as the command has been
104  * sent downwards the stack to the TPM. All input parameters are const.
105  * In order to retrieve the TPM's response call Esys_ReadClock_Finish.
106  *
107  * @param[in,out] esysContext The ESYS_CONTEXT.
108  * @param[in]  shandle1 First session handle.
109  * @param[in]  shandle2 Second session handle.
110  * @param[in]  shandle3 Third session handle.
111  * @retval ESYS_RC_SUCCESS if the function call was a success.
112  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
113  *         pointers or required output handle references are NULL.
114  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
115  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
116  *         internal operations or return parameters.
117  * @retval TSS2_RCs produced by lower layers of the software stack may be
118            returned to the caller unaltered unless handled internally.
119  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
120  *         the 'decrypt' attribute bit set.
121  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
122  *         the 'encrypt' attribute bit set.
123  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
124  *         'decrypt' attribute set and the command does not support encryption
125  *         of the first command parameter.
126  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
127  *         'encrypt' attribute set and the command does not support encryption
128  *          of the first response parameter.
129  */
130 TSS2_RC
Esys_ReadClock_Async(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3)131 Esys_ReadClock_Async(
132     ESYS_CONTEXT *esysContext,
133     ESYS_TR shandle1,
134     ESYS_TR shandle2,
135     ESYS_TR shandle3)
136 {
137     TSS2_RC r;
138     LOG_TRACE("context=%p",
139               esysContext);
140     TSS2L_SYS_AUTH_COMMAND auths;
141 
142     /* Check context, sequence correctness and set state to error for now */
143     if (esysContext == NULL) {
144         LOG_ERROR("esyscontext is NULL.");
145         return TSS2_ESYS_RC_BAD_REFERENCE;
146     }
147     r = iesys_check_sequence_async(esysContext);
148     if (r != TSS2_RC_SUCCESS)
149         return r;
150     esysContext->state = _ESYS_STATE_INTERNALERROR;
151 
152     /* Check input parameters */
153     r = check_session_feasibility(shandle1, shandle2, shandle3, 0);
154     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
155 
156     /* Initial invocation of SAPI to prepare the command buffer with parameters */
157     r = Tss2_Sys_ReadClock_Prepare(esysContext->sys);
158     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
159 
160     /* Calculate the cpHash Values */
161     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
162     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
163     iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
164     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
165     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
166 
167     /* Generate the auth values and set them in the SAPI command buffer */
168     r = iesys_gen_auths(esysContext, NULL, NULL, NULL, &auths);
169     return_state_if_error(r, _ESYS_STATE_INIT,
170                           "Error in computation of auth values");
171 
172     esysContext->authsCount = auths.count;
173     if (auths.count > 0) {
174         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
175         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
176     }
177 
178     /* Trigger execution and finish the async invocation */
179     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
180     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
181                           "Finish (Execute Async)");
182 
183     esysContext->state = _ESYS_STATE_SENT;
184 
185     return r;
186 }
187 
188 /** Asynchronous finish function for TPM2_ReadClock
189  *
190  * This function returns the results of a TPM2_ReadClock command
191  * invoked via Esys_ReadClock_Finish. All non-simple output parameters
192  * are allocated by the function's implementation. NULL can be passed for every
193  * output parameter if the value is not required.
194  *
195  * @param[in,out] esysContext The ESYS_CONTEXT.
196  * @param[out] currentTime .
197  *             (callee-allocated)
198  * @retval TSS2_RC_SUCCESS on success
199  * @retval ESYS_RC_SUCCESS if the function call was a success.
200  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
201  *         pointers or required output handle references are NULL.
202  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
203  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
204  *         internal operations or return parameters.
205  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
206  *         operation already pending.
207  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
208  *         TPM response is received.
209  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
210  *         at least contain the tag, response length, and response code.
211  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
212  *         not verify.
213  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
214  * @retval TSS2_RCs produced by lower layers of the software stack may be
215  *         returned to the caller unaltered unless handled internally.
216  */
217 TSS2_RC
Esys_ReadClock_Finish(ESYS_CONTEXT * esysContext,TPMS_TIME_INFO ** currentTime)218 Esys_ReadClock_Finish(
219     ESYS_CONTEXT *esysContext,
220     TPMS_TIME_INFO **currentTime)
221 {
222     TSS2_RC r;
223     LOG_TRACE("context=%p, currentTime=%p",
224               esysContext, currentTime);
225 
226     if (esysContext == NULL) {
227         LOG_ERROR("esyscontext is NULL.");
228         return TSS2_ESYS_RC_BAD_REFERENCE;
229     }
230 
231     /* Check for correct sequence and set sequence to irregular for now */
232     if (esysContext->state != _ESYS_STATE_SENT &&
233         esysContext->state != _ESYS_STATE_RESUBMISSION) {
234         LOG_ERROR("Esys called in bad sequence.");
235         return TSS2_ESYS_RC_BAD_SEQUENCE;
236     }
237     esysContext->state = _ESYS_STATE_INTERNALERROR;
238 
239     /* Allocate memory for response parameters */
240     if (currentTime != NULL) {
241         *currentTime = calloc(sizeof(TPMS_TIME_INFO), 1);
242         if (*currentTime == NULL) {
243             return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
244         }
245     }
246 
247     /*Receive the TPM response and handle resubmissions if necessary. */
248     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
249     if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN) {
250         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
251         esysContext->state = _ESYS_STATE_SENT;
252         goto error_cleanup;
253     }
254     /* This block handle the resubmission of TPM commands given a certain set of
255      * TPM response codes. */
256     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
257         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
258             "resubmission: %" PRIx32, r);
259         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
260             LOG_WARNING("Maximum number of (re)submissions has been reached.");
261             esysContext->state = _ESYS_STATE_INIT;
262             goto error_cleanup;
263         }
264         esysContext->state = _ESYS_STATE_RESUBMISSION;
265         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
266         if (r != TSS2_RC_SUCCESS) {
267             LOG_WARNING("Error attempting to resubmit");
268             /* We do not set esysContext->state here but inherit the most recent
269              * state of the _async function. */
270             goto error_cleanup;
271         }
272         r = TSS2_ESYS_RC_TRY_AGAIN;
273         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
274         goto error_cleanup;
275     }
276     /* The following is the "regular error" handling. */
277     if (iesys_tpm_error(r)) {
278         LOG_WARNING("Received TPM Error");
279         esysContext->state = _ESYS_STATE_INIT;
280         goto error_cleanup;
281     } else if (r != TSS2_RC_SUCCESS) {
282         LOG_ERROR("Received a non-TPM Error");
283         esysContext->state = _ESYS_STATE_INTERNALERROR;
284         goto error_cleanup;
285     }
286 
287     /*
288      * Now the verification of the response (hmac check) and if necessary the
289      * parameter decryption have to be done.
290      */
291     r = iesys_check_response(esysContext);
292     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
293                         error_cleanup);
294 
295     /*
296      * After the verification of the response we call the complete function
297      * to deliver the result.
298      */
299     r = Tss2_Sys_ReadClock_Complete(esysContext->sys,
300                                     (currentTime != NULL) ? *currentTime
301                                      : NULL);
302     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
303                         "Received error from SAPI unmarshaling" ,
304                         error_cleanup);
305 
306     esysContext->state = _ESYS_STATE_INIT;
307 
308     return TSS2_RC_SUCCESS;
309 
310 error_cleanup:
311     if (currentTime != NULL)
312         SAFE_FREE(*currentTime);
313 
314     return r;
315 }
316