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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_PCR_Read
23  *
24  * This function invokes the TPM2_PCR_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]  shandle1 First session handle.
31  * @param[in]  shandle2 Second session handle.
32  * @param[in]  shandle3 Third session handle.
33  * @param[in]  pcrSelectionIn The selection of PCR to read.
34  * @param[out] pcrUpdateCounter The current value of the PCR update counter.
35  *             (callee-allocated)
36  * @param[out] pcrSelectionOut The PCR in the returned list.
37  *             (callee-allocated)
38  * @param[out] pcrValues The contents of the PCR indicated in pcrSelectOut->
39  *             pcrSelection[] as tagged digests.
40  *             (callee-allocated)
41  * @retval TSS2_RC_SUCCESS if the function call was a success.
42  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
43  *         pointers or required output handle references are NULL.
44  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
45  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
46  *         internal operations or return parameters.
47  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
48  *         operation already pending.
49  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
50  *          at least contain the tag, response length, and response code.
51  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
52  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
53            did not verify.
54  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
55  *         the 'decrypt' attribute bit set.
56  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
57  *         the 'encrypt' attribute bit set.
58  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
59  *         'decrypt' attribute set and the command does not support encryption
60  *         of the first command parameter.
61  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
62  *         'encrypt' attribute set and the command does not support encryption
63  *          of the first response parameter.
64  * @retval TSS2_RCs produced by lower layers of the software stack may be
65  *         returned to the caller unaltered unless handled internally.
66  */
67 TSS2_RC
Esys_PCR_Read(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPML_PCR_SELECTION * pcrSelectionIn,UINT32 * pcrUpdateCounter,TPML_PCR_SELECTION ** pcrSelectionOut,TPML_DIGEST ** pcrValues)68 Esys_PCR_Read(
69     ESYS_CONTEXT *esysContext,
70     ESYS_TR shandle1,
71     ESYS_TR shandle2,
72     ESYS_TR shandle3,
73     const TPML_PCR_SELECTION *pcrSelectionIn,
74     UINT32 *pcrUpdateCounter,
75     TPML_PCR_SELECTION **pcrSelectionOut,
76     TPML_DIGEST **pcrValues)
77 {
78     TSS2_RC r;
79 
80     r = Esys_PCR_Read_Async(esysContext, shandle1, shandle2, shandle3,
81                             pcrSelectionIn);
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_PCR_Read_Finish(esysContext, pcrUpdateCounter, pcrSelectionOut,
96                                  pcrValues);
97         /* This is just debug information about the reattempt to finish the
98            command */
99         if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN)
100             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
101                       " => resubmitting command", r);
102     } while ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN);
103 
104     /* Restore the timeout value to the original value */
105     esysContext->timeout = timeouttmp;
106     return_if_error(r, "Esys Finish");
107 
108     return TSS2_RC_SUCCESS;
109 }
110 
111 /** Asynchronous function for TPM2_PCR_Read
112  *
113  * This function invokes the TPM2_PCR_Read command in a asynchronous
114  * variant. This means the function will return as soon as the command has been
115  * sent downwards the stack to the TPM. All input parameters are const.
116  * In order to retrieve the TPM's response call Esys_PCR_Read_Finish.
117  *
118  * @param[in,out] esysContext The ESYS_CONTEXT.
119  * @param[in]  shandle1 First session handle.
120  * @param[in]  shandle2 Second session handle.
121  * @param[in]  shandle3 Third session handle.
122  * @param[in]  pcrSelectionIn The selection of PCR to read.
123  * @retval ESYS_RC_SUCCESS if the function call was a success.
124  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
125  *         pointers or required output handle references are NULL.
126  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
127  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
128  *         internal operations or return parameters.
129  * @retval TSS2_RCs produced by lower layers of the software stack may be
130            returned to the caller unaltered unless handled internally.
131  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
132  *         the 'decrypt' attribute bit set.
133  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
134  *         the 'encrypt' attribute bit set.
135  * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
136  *         'decrypt' attribute set and the command does not support encryption
137  *         of the first command parameter.
138  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
139  *         'encrypt' attribute set and the command does not support encryption
140  *          of the first response parameter.
141  */
142 TSS2_RC
Esys_PCR_Read_Async(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPML_PCR_SELECTION * pcrSelectionIn)143 Esys_PCR_Read_Async(
144     ESYS_CONTEXT *esysContext,
145     ESYS_TR shandle1,
146     ESYS_TR shandle2,
147     ESYS_TR shandle3,
148     const TPML_PCR_SELECTION *pcrSelectionIn)
149 {
150     TSS2_RC r;
151     LOG_TRACE("context=%p, pcrSelectionIn=%p",
152               esysContext, pcrSelectionIn);
153     TSS2L_SYS_AUTH_COMMAND auths;
154 
155     /* Check context, sequence correctness and set state to error for now */
156     if (esysContext == NULL) {
157         LOG_ERROR("esyscontext is NULL.");
158         return TSS2_ESYS_RC_BAD_REFERENCE;
159     }
160     r = iesys_check_sequence_async(esysContext);
161     if (r != TSS2_RC_SUCCESS)
162         return r;
163     esysContext->state = _ESYS_STATE_INTERNALERROR;
164 
165     /* Check input parameters */
166     r = check_session_feasibility(shandle1, shandle2, shandle3, 0);
167     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
168 
169     /* Initial invocation of SAPI to prepare the command buffer with parameters */
170     r = Tss2_Sys_PCR_Read_Prepare(esysContext->sys, pcrSelectionIn);
171     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
172 
173     /* Calculate the cpHash Values */
174     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
175     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
176     iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
177     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
178     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
179 
180     /* Generate the auth values and set them in the SAPI command buffer */
181     r = iesys_gen_auths(esysContext, NULL, NULL, NULL, &auths);
182     return_state_if_error(r, _ESYS_STATE_INIT,
183                           "Error in computation of auth values");
184 
185     esysContext->authsCount = auths.count;
186     if (auths.count > 0) {
187         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
188         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
189     }
190 
191     /* Trigger execution and finish the async invocation */
192     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
193     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
194                           "Finish (Execute Async)");
195 
196     esysContext->state = _ESYS_STATE_SENT;
197 
198     return r;
199 }
200 
201 /** Asynchronous finish function for TPM2_PCR_Read
202  *
203  * This function returns the results of a TPM2_PCR_Read command
204  * invoked via Esys_PCR_Read_Finish. All non-simple output parameters
205  * are allocated by the function's implementation. NULL can be passed for every
206  * output parameter if the value is not required.
207  *
208  * @param[in,out] esysContext The ESYS_CONTEXT.
209  * @param[out] pcrUpdateCounter The current value of the PCR update counter.
210  *             (callee-allocated)
211  * @param[out] pcrSelectionOut The PCR in the returned list.
212  *             (callee-allocated)
213  * @param[out] pcrValues The contents of the PCR indicated in pcrSelectOut->
214  *             pcrSelection[] as tagged digests.
215  *             (callee-allocated)
216  * @retval TSS2_RC_SUCCESS on success
217  * @retval ESYS_RC_SUCCESS if the function call was a success.
218  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
219  *         pointers or required output handle references are NULL.
220  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
221  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
222  *         internal operations or return parameters.
223  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
224  *         operation already pending.
225  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
226  *         TPM response is received.
227  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
228  *         at least contain the tag, response length, and response code.
229  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
230  *         not verify.
231  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
232  * @retval TSS2_RCs produced by lower layers of the software stack may be
233  *         returned to the caller unaltered unless handled internally.
234  */
235 TSS2_RC
Esys_PCR_Read_Finish(ESYS_CONTEXT * esysContext,UINT32 * pcrUpdateCounter,TPML_PCR_SELECTION ** pcrSelectionOut,TPML_DIGEST ** pcrValues)236 Esys_PCR_Read_Finish(
237     ESYS_CONTEXT *esysContext,
238     UINT32 *pcrUpdateCounter,
239     TPML_PCR_SELECTION **pcrSelectionOut,
240     TPML_DIGEST **pcrValues)
241 {
242     TSS2_RC r;
243     LOG_TRACE("context=%p, pcrUpdateCounter=%p, pcrSelectionOut=%p,"
244               "pcrValues=%p",
245               esysContext, pcrUpdateCounter, pcrSelectionOut,
246               pcrValues);
247 
248     if (esysContext == NULL) {
249         LOG_ERROR("esyscontext is NULL.");
250         return TSS2_ESYS_RC_BAD_REFERENCE;
251     }
252 
253     /* Check for correct sequence and set sequence to irregular for now */
254     if (esysContext->state != _ESYS_STATE_SENT &&
255         esysContext->state != _ESYS_STATE_RESUBMISSION) {
256         LOG_ERROR("Esys called in bad sequence.");
257         return TSS2_ESYS_RC_BAD_SEQUENCE;
258     }
259     esysContext->state = _ESYS_STATE_INTERNALERROR;
260 
261     /* Allocate memory for response parameters */
262     if (pcrSelectionOut != NULL) {
263         *pcrSelectionOut = calloc(sizeof(TPML_PCR_SELECTION), 1);
264         if (*pcrSelectionOut == NULL) {
265             return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
266         }
267     }
268     if (pcrValues != NULL) {
269         *pcrValues = calloc(sizeof(TPML_DIGEST), 1);
270         if (*pcrValues == NULL) {
271             goto_error(r, TSS2_ESYS_RC_MEMORY, "Out of memory", error_cleanup);
272         }
273     }
274 
275     /*Receive the TPM response and handle resubmissions if necessary. */
276     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
277     if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN) {
278         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
279         esysContext->state = _ESYS_STATE_SENT;
280         goto error_cleanup;
281     }
282     /* This block handle the resubmission of TPM commands given a certain set of
283      * TPM response codes. */
284     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
285         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
286             "resubmission: %" PRIx32, r);
287         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
288             LOG_WARNING("Maximum number of (re)submissions has been reached.");
289             esysContext->state = _ESYS_STATE_INIT;
290             goto error_cleanup;
291         }
292         esysContext->state = _ESYS_STATE_RESUBMISSION;
293         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
294         if (r != TSS2_RC_SUCCESS) {
295             LOG_WARNING("Error attempting to resubmit");
296             /* We do not set esysContext->state here but inherit the most recent
297              * state of the _async function. */
298             goto error_cleanup;
299         }
300         r = TSS2_ESYS_RC_TRY_AGAIN;
301         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
302         goto error_cleanup;
303     }
304     /* The following is the "regular error" handling. */
305     if (iesys_tpm_error(r)) {
306         LOG_WARNING("Received TPM Error");
307         esysContext->state = _ESYS_STATE_INIT;
308         goto error_cleanup;
309     } else if (r != TSS2_RC_SUCCESS) {
310         LOG_ERROR("Received a non-TPM Error");
311         esysContext->state = _ESYS_STATE_INTERNALERROR;
312         goto error_cleanup;
313     }
314 
315     /*
316      * Now the verification of the response (hmac check) and if necessary the
317      * parameter decryption have to be done.
318      */
319     r = iesys_check_response(esysContext);
320     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
321                         error_cleanup);
322 
323     /*
324      * After the verification of the response we call the complete function
325      * to deliver the result.
326      */
327     r = Tss2_Sys_PCR_Read_Complete(esysContext->sys, pcrUpdateCounter,
328                                    (pcrSelectionOut != NULL) ? *pcrSelectionOut
329                                     : NULL,
330                                    (pcrValues != NULL) ? *pcrValues : NULL);
331     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
332                         "Received error from SAPI unmarshaling" ,
333                         error_cleanup);
334 
335     esysContext->state = _ESYS_STATE_INIT;
336 
337     return TSS2_RC_SUCCESS;
338 
339 error_cleanup:
340     if (pcrSelectionOut != NULL)
341         SAFE_FREE(*pcrSelectionOut);
342     if (pcrValues != NULL)
343         SAFE_FREE(*pcrValues);
344 
345     return r;
346 }
347