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_PolicyPCR
23  *
24  * This function invokes the TPM2_PolicyPCR 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]  policySession Handle for the policy session being extended.
31  * @param[in]  shandle1 First session handle.
32  * @param[in]  shandle2 Second session handle.
33  * @param[in]  shandle3 Third session handle.
34  * @param[in]  pcrDigest Expected digest value of the selected PCR using the
35  *             hash algorithm of the session; may be zero length.
36  * @param[in]  pcrs The PCR to include in the check digest.
37  * @retval TSS2_RC_SUCCESS if the function call was a success.
38  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
39  *         pointers or required output handle references are NULL.
40  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
41  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
42  *         internal operations or return parameters.
43  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
44  *         operation already pending.
45  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
46  *          at least contain the tag, response length, and response code.
47  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
48  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
49            did not verify.
50  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
51  *         the 'decrypt' attribute bit set.
52  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
53  *         the 'encrypt' attribute bit set.
54  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
55  *         to the ESYS_CONTEXT or are of the wrong type or if required
56  *         ESYS_TR objects are ESYS_TR_NONE.
57  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
58  *         'encrypt' attribute set and the command does not support encryption
59  *          of the first response parameter.
60  * @retval TSS2_RCs produced by lower layers of the software stack may be
61  *         returned to the caller unaltered unless handled internally.
62  */
63 TSS2_RC
Esys_PolicyPCR(ESYS_CONTEXT * esysContext,ESYS_TR policySession,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_DIGEST * pcrDigest,const TPML_PCR_SELECTION * pcrs)64 Esys_PolicyPCR(
65     ESYS_CONTEXT *esysContext,
66     ESYS_TR policySession,
67     ESYS_TR shandle1,
68     ESYS_TR shandle2,
69     ESYS_TR shandle3,
70     const TPM2B_DIGEST *pcrDigest,
71     const TPML_PCR_SELECTION *pcrs)
72 {
73     TSS2_RC r;
74 
75     r = Esys_PolicyPCR_Async(esysContext, policySession, shandle1, shandle2,
76                              shandle3, pcrDigest, pcrs);
77     return_if_error(r, "Error in async function");
78 
79     /* Set the timeout to indefinite for now, since we want _Finish to block */
80     int32_t timeouttmp = esysContext->timeout;
81     esysContext->timeout = -1;
82     /*
83      * Now we call the finish function, until return code is not equal to
84      * from TSS2_BASE_RC_TRY_AGAIN.
85      * Note that the finish function may return TSS2_RC_TRY_AGAIN, even if we
86      * have set the timeout to -1. This occurs for example if the TPM requests
87      * a retransmission of the command via TPM2_RC_YIELDED.
88      */
89     do {
90         r = Esys_PolicyPCR_Finish(esysContext);
91         /* This is just debug information about the reattempt to finish the
92            command */
93         if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN)
94             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
95                       " => resubmitting command", r);
96     } while (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN);
97 
98     /* Restore the timeout value to the original value */
99     esysContext->timeout = timeouttmp;
100     return_if_error(r, "Esys Finish");
101 
102     return TSS2_RC_SUCCESS;
103 }
104 
105 /** Asynchronous function for TPM2_PolicyPCR
106  *
107  * This function invokes the TPM2_PolicyPCR command in a asynchronous
108  * variant. This means the function will return as soon as the command has been
109  * sent downwards the stack to the TPM. All input parameters are const.
110  * In order to retrieve the TPM's response call Esys_PolicyPCR_Finish.
111  *
112  * @param[in,out] esysContext The ESYS_CONTEXT.
113  * @param[in]  policySession Handle for the policy session being extended.
114  * @param[in]  shandle1 First session handle.
115  * @param[in]  shandle2 Second session handle.
116  * @param[in]  shandle3 Third session handle.
117  * @param[in]  pcrDigest Expected digest value of the selected PCR using the
118  *             hash algorithm of the session; may be zero length.
119  * @param[in]  pcrs The PCR to include in the check digest.
120  * @retval ESYS_RC_SUCCESS if the function call was a success.
121  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
122  *         pointers or required output handle references are NULL.
123  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
124  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
125  *         internal operations or return parameters.
126  * @retval TSS2_RCs produced by lower layers of the software stack may be
127            returned to the caller unaltered unless handled internally.
128  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
129  *         the 'decrypt' attribute bit set.
130  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
131  *         the 'encrypt' attribute bit set.
132  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
133  *         to the ESYS_CONTEXT or are of the wrong type or if required
134  *         ESYS_TR objects are ESYS_TR_NONE.
135  * @retval TSS2_ESYS_RC_NO_ENCRYPT_PARAM: if one of the sessions has the
136  *         'encrypt' attribute set and the command does not support encryption
137  *          of the first response parameter.
138  */
139 TSS2_RC
Esys_PolicyPCR_Async(ESYS_CONTEXT * esysContext,ESYS_TR policySession,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_DIGEST * pcrDigest,const TPML_PCR_SELECTION * pcrs)140 Esys_PolicyPCR_Async(
141     ESYS_CONTEXT *esysContext,
142     ESYS_TR policySession,
143     ESYS_TR shandle1,
144     ESYS_TR shandle2,
145     ESYS_TR shandle3,
146     const TPM2B_DIGEST *pcrDigest,
147     const TPML_PCR_SELECTION *pcrs)
148 {
149     TSS2_RC r;
150     LOG_TRACE("context=%p, policySession=%"PRIx32 ", pcrDigest=%p,"
151               "pcrs=%p",
152               esysContext, policySession, pcrDigest, pcrs);
153     TSS2L_SYS_AUTH_COMMAND auths;
154     RSRC_NODE_T *policySessionNode;
155 
156     /* Check context, sequence correctness and set state to error for now */
157     if (esysContext == NULL) {
158         LOG_ERROR("esyscontext is NULL.");
159         return TSS2_ESYS_RC_BAD_REFERENCE;
160     }
161     r = iesys_check_sequence_async(esysContext);
162     if (r != TSS2_RC_SUCCESS)
163         return r;
164     esysContext->state = _ESYS_STATE_INTERNALERROR;
165 
166     /* Check input parameters */
167     r = check_session_feasibility(shandle1, shandle2, shandle3, 0);
168     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
169 
170     /* Retrieve the metadata objects for provided handles */
171     r = esys_GetResourceObject(esysContext, policySession, &policySessionNode);
172     return_state_if_error(r, _ESYS_STATE_INIT, "policySession unknown.");
173 
174     /* Initial invocation of SAPI to prepare the command buffer with parameters */
175     r = Tss2_Sys_PolicyPCR_Prepare(esysContext->sys,
176                                    (policySessionNode == NULL) ? TPM2_RH_NULL
177                                     : policySessionNode->rsrc.handle, pcrDigest,
178                                    pcrs);
179     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
180 
181     /* Calculate the cpHash Values */
182     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
183     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
184     iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
185     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
186     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
187 
188     /* Generate the auth values and set them in the SAPI command buffer */
189     r = iesys_gen_auths(esysContext, policySessionNode, NULL, NULL, &auths);
190     return_state_if_error(r, _ESYS_STATE_INIT,
191                           "Error in computation of auth values");
192 
193     esysContext->authsCount = auths.count;
194     if (auths.count > 0) {
195         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
196         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
197     }
198 
199     /* Trigger execution and finish the async invocation */
200     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
201     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
202                           "Finish (Execute Async)");
203 
204     esysContext->state = _ESYS_STATE_SENT;
205 
206     return r;
207 }
208 
209 /** Asynchronous finish function for TPM2_PolicyPCR
210  *
211  * This function returns the results of a TPM2_PolicyPCR command
212  * invoked via Esys_PolicyPCR_Finish. All non-simple output parameters
213  * are allocated by the function's implementation. NULL can be passed for every
214  * output parameter if the value is not required.
215  *
216  * @param[in,out] esysContext The ESYS_CONTEXT.
217  * @retval TSS2_RC_SUCCESS on success
218  * @retval ESYS_RC_SUCCESS if the function call was a success.
219  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
220  *         pointers or required output handle references are NULL.
221  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
222  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
223  *         internal operations or return parameters.
224  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
225  *         operation already pending.
226  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
227  *         TPM response is received.
228  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
229  *         at least contain the tag, response length, and response code.
230  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
231  *         not verify.
232  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
233  * @retval TSS2_RCs produced by lower layers of the software stack may be
234  *         returned to the caller unaltered unless handled internally.
235  */
236 TSS2_RC
Esys_PolicyPCR_Finish(ESYS_CONTEXT * esysContext)237 Esys_PolicyPCR_Finish(
238     ESYS_CONTEXT *esysContext)
239 {
240     TSS2_RC r;
241     LOG_TRACE("context=%p",
242               esysContext);
243 
244     if (esysContext == NULL) {
245         LOG_ERROR("esyscontext is NULL.");
246         return TSS2_ESYS_RC_BAD_REFERENCE;
247     }
248 
249     /* Check for correct sequence and set sequence to irregular for now */
250     if (esysContext->state != _ESYS_STATE_SENT &&
251         esysContext->state != _ESYS_STATE_RESUBMISSION) {
252         LOG_ERROR("Esys called in bad sequence.");
253         return TSS2_ESYS_RC_BAD_SEQUENCE;
254     }
255     esysContext->state = _ESYS_STATE_INTERNALERROR;
256 
257     /*Receive the TPM response and handle resubmissions if necessary. */
258     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
259     if (base_rc(r) == TSS2_BASE_RC_TRY_AGAIN) {
260         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
261         esysContext->state = _ESYS_STATE_SENT;
262         return r;
263     }
264     /* This block handle the resubmission of TPM commands given a certain set of
265      * TPM response codes. */
266     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
267         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
268             "resubmission: %" PRIx32, r);
269         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
270             LOG_WARNING("Maximum number of (re)submissions has been reached.");
271             esysContext->state = _ESYS_STATE_INIT;
272             return r;
273         }
274         esysContext->state = _ESYS_STATE_RESUBMISSION;
275         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
276         if (r != TSS2_RC_SUCCESS) {
277             LOG_WARNING("Error attempting to resubmit");
278             /* We do not set esysContext->state here but inherit the most recent
279              * state of the _async function. */
280             return r;
281         }
282         r = TSS2_ESYS_RC_TRY_AGAIN;
283         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
284         return r;
285     }
286     /* The following is the "regular error" handling. */
287     if (iesys_tpm_error(r)) {
288         LOG_WARNING("Received TPM Error");
289         esysContext->state = _ESYS_STATE_INIT;
290         return r;
291     } else if (r != TSS2_RC_SUCCESS) {
292         LOG_ERROR("Received a non-TPM Error");
293         esysContext->state = _ESYS_STATE_INTERNALERROR;
294         return r;
295     }
296 
297     /*
298      * Now the verification of the response (hmac check) and if necessary the
299      * parameter decryption have to be done.
300      */
301     r = iesys_check_response(esysContext);
302     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
303                           "Error: check response");
304 
305     /*
306      * After the verification of the response we call the complete function
307      * to deliver the result.
308      */
309     r = Tss2_Sys_PolicyPCR_Complete(esysContext->sys);
310     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
311                           "Received error from SAPI unmarshaling" );
312 
313     esysContext->state = _ESYS_STATE_INIT;
314 
315     return TSS2_RC_SUCCESS;
316 }
317