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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_ZGen_2Phase
23  *
24  * This function invokes the TPM2_ZGen_2Phase 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]  keyA Handle of an unrestricted decryption key ECC.
31  * @param[in]  shandle1 Session handle for authorization of keyA
32  * @param[in]  shandle2 Second session handle.
33  * @param[in]  shandle3 Third session handle.
34  * @param[in]  inQsB Other party's static public key (Qs,B = (Xs,B, Ys,B)).
35  * @param[in]  inQeB Other party's ephemeral public key (Qe,B = (Xe,B, Ye,B)).
36  * @param[in]  inScheme The key exchange scheme.
37  * @param[in]  counter Value returned by TPM2_EC_Ephemeral().
38  * @param[out] outZ1 X and Y coordinates of the computed value (scheme
39  *             dependent).
40  *             (callee-allocated)
41  * @param[out] outZ2 X and Y coordinates of the second computed value (scheme
42  *             dependent).
43  *             (callee-allocated)
44  * @retval TSS2_RC_SUCCESS if the function call was a success.
45  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
46  *         pointers or required output handle references are NULL.
47  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
48  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
49  *         internal operations or return parameters.
50  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
51  *         operation already pending.
52  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
53  *          at least contain the tag, response length, and response code.
54  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
55  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
56            did not verify.
57  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
58  *         the 'decrypt' attribute bit set.
59  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
60  *         the 'encrypt' attribute bit set.
61  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
62  *         to the ESYS_CONTEXT or are of the wrong type or if required
63  *         ESYS_TR objects are ESYS_TR_NONE.
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_ZGen_2Phase(ESYS_CONTEXT * esysContext,ESYS_TR keyA,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_ECC_POINT * inQsB,const TPM2B_ECC_POINT * inQeB,TPMI_ECC_KEY_EXCHANGE inScheme,UINT16 counter,TPM2B_ECC_POINT ** outZ1,TPM2B_ECC_POINT ** outZ2)68 Esys_ZGen_2Phase(
69     ESYS_CONTEXT *esysContext,
70     ESYS_TR keyA,
71     ESYS_TR shandle1,
72     ESYS_TR shandle2,
73     ESYS_TR shandle3,
74     const TPM2B_ECC_POINT *inQsB,
75     const TPM2B_ECC_POINT *inQeB,
76     TPMI_ECC_KEY_EXCHANGE inScheme,
77     UINT16 counter,
78     TPM2B_ECC_POINT **outZ1,
79     TPM2B_ECC_POINT **outZ2)
80 {
81     TSS2_RC r;
82 
83     r = Esys_ZGen_2Phase_Async(esysContext, keyA, shandle1, shandle2, shandle3,
84                                inQsB, inQeB, inScheme, counter);
85     return_if_error(r, "Error in async function");
86 
87     /* Set the timeout to indefinite for now, since we want _Finish to block */
88     int32_t timeouttmp = esysContext->timeout;
89     esysContext->timeout = -1;
90     /*
91      * Now we call the finish function, until return code is not equal to
92      * from TSS2_BASE_RC_TRY_AGAIN.
93      * Note that the finish function may return TSS2_RC_TRY_AGAIN, even if we
94      * have set the timeout to -1. This occurs for example if the TPM requests
95      * a retransmission of the command via TPM2_RC_YIELDED.
96      */
97     do {
98         r = Esys_ZGen_2Phase_Finish(esysContext, outZ1, outZ2);
99         /* This is just debug information about the reattempt to finish the
100            command */
101         if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN)
102             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
103                       " => resubmitting command", r);
104     } while ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN);
105 
106     /* Restore the timeout value to the original value */
107     esysContext->timeout = timeouttmp;
108     return_if_error(r, "Esys Finish");
109 
110     return TSS2_RC_SUCCESS;
111 }
112 
113 /** Asynchronous function for TPM2_ZGen_2Phase
114  *
115  * This function invokes the TPM2_ZGen_2Phase command in a asynchronous
116  * variant. This means the function will return as soon as the command has been
117  * sent downwards the stack to the TPM. All input parameters are const.
118  * In order to retrieve the TPM's response call Esys_ZGen_2Phase_Finish.
119  *
120  * @param[in,out] esysContext The ESYS_CONTEXT.
121  * @param[in]  keyA Handle of an unrestricted decryption key ECC.
122  * @param[in]  shandle1 Session handle for authorization of keyA
123  * @param[in]  shandle2 Second session handle.
124  * @param[in]  shandle3 Third session handle.
125  * @param[in]  inQsB Other party's static public key (Qs,B = (Xs,B, Ys,B)).
126  * @param[in]  inQeB Other party's ephemeral public key (Qe,B = (Xe,B, Ye,B)).
127  * @param[in]  inScheme The key exchange scheme.
128  * @param[in]  counter Value returned by TPM2_EC_Ephemeral().
129  * @retval ESYS_RC_SUCCESS if the function call was a success.
130  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
131  *         pointers or required output handle references are NULL.
132  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
133  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
134  *         internal operations or return parameters.
135  * @retval TSS2_RCs produced by lower layers of the software stack may be
136            returned to the caller unaltered unless handled internally.
137  * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
138  *         the 'decrypt' attribute bit set.
139  * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
140  *         the 'encrypt' attribute bit set.
141  * @retval TSS2_ESYS_RC_BAD_TR: if any of the ESYS_TR objects are unknown
142  *         to the ESYS_CONTEXT or are of the wrong type or if required
143  *         ESYS_TR objects are ESYS_TR_NONE.
144  */
145 TSS2_RC
Esys_ZGen_2Phase_Async(ESYS_CONTEXT * esysContext,ESYS_TR keyA,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_ECC_POINT * inQsB,const TPM2B_ECC_POINT * inQeB,TPMI_ECC_KEY_EXCHANGE inScheme,UINT16 counter)146 Esys_ZGen_2Phase_Async(
147     ESYS_CONTEXT *esysContext,
148     ESYS_TR keyA,
149     ESYS_TR shandle1,
150     ESYS_TR shandle2,
151     ESYS_TR shandle3,
152     const TPM2B_ECC_POINT *inQsB,
153     const TPM2B_ECC_POINT *inQeB,
154     TPMI_ECC_KEY_EXCHANGE inScheme,
155     UINT16 counter)
156 {
157     TSS2_RC r;
158     LOG_TRACE("context=%p, keyA=%"PRIx32 ", inQsB=%p,"
159               "inQeB=%p, inScheme=%04"PRIx16", counter=%04"PRIx16"",
160               esysContext, keyA, inQsB, inQeB, inScheme,
161               counter);
162     TSS2L_SYS_AUTH_COMMAND auths;
163     RSRC_NODE_T *keyANode;
164 
165     /* Check context, sequence correctness and set state to error for now */
166     if (esysContext == NULL) {
167         LOG_ERROR("esyscontext is NULL.");
168         return TSS2_ESYS_RC_BAD_REFERENCE;
169     }
170     r = iesys_check_sequence_async(esysContext);
171     if (r != TSS2_RC_SUCCESS)
172         return r;
173     esysContext->state = _ESYS_STATE_INTERNALERROR;
174 
175     /* Check input parameters */
176     r = check_session_feasibility(shandle1, shandle2, shandle3, 1);
177     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
178 
179     /* Retrieve the metadata objects for provided handles */
180     r = esys_GetResourceObject(esysContext, keyA, &keyANode);
181     return_state_if_error(r, _ESYS_STATE_INIT, "keyA unknown.");
182 
183     /* Initial invocation of SAPI to prepare the command buffer with parameters */
184     r = Tss2_Sys_ZGen_2Phase_Prepare(esysContext->sys,
185                                      (keyANode == NULL) ? TPM2_RH_NULL
186                                       : keyANode->rsrc.handle, inQsB, inQeB,
187                                      inScheme, counter);
188     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
189 
190     /* Calculate the cpHash Values */
191     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
192     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
193     if (keyANode != NULL)
194         iesys_compute_session_value(esysContext->session_tab[0],
195                 &keyANode->rsrc.name, &keyANode->auth);
196     else
197         iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
198 
199     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
200     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
201 
202     /* Generate the auth values and set them in the SAPI command buffer */
203     r = iesys_gen_auths(esysContext, keyANode, NULL, NULL, &auths);
204     return_state_if_error(r, _ESYS_STATE_INIT,
205                           "Error in computation of auth values");
206 
207     esysContext->authsCount = auths.count;
208     if (auths.count > 0) {
209         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
210         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
211     }
212 
213     /* Trigger execution and finish the async invocation */
214     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
215     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
216                           "Finish (Execute Async)");
217 
218     esysContext->state = _ESYS_STATE_SENT;
219 
220     return r;
221 }
222 
223 /** Asynchronous finish function for TPM2_ZGen_2Phase
224  *
225  * This function returns the results of a TPM2_ZGen_2Phase command
226  * invoked via Esys_ZGen_2Phase_Finish. All non-simple output parameters
227  * are allocated by the function's implementation. NULL can be passed for every
228  * output parameter if the value is not required.
229  *
230  * @param[in,out] esysContext The ESYS_CONTEXT.
231  * @param[out] outZ1 X and Y coordinates of the computed value (scheme
232  *             dependent).
233  *             (callee-allocated)
234  * @param[out] outZ2 X and Y coordinates of the second computed value (scheme
235  *             dependent).
236  *             (callee-allocated)
237  * @retval TSS2_RC_SUCCESS on success
238  * @retval ESYS_RC_SUCCESS if the function call was a success.
239  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
240  *         pointers or required output handle references are NULL.
241  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
242  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
243  *         internal operations or return parameters.
244  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
245  *         operation already pending.
246  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
247  *         TPM response is received.
248  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
249  *         at least contain the tag, response length, and response code.
250  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
251  *         not verify.
252  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
253  * @retval TSS2_RCs produced by lower layers of the software stack may be
254  *         returned to the caller unaltered unless handled internally.
255  */
256 TSS2_RC
Esys_ZGen_2Phase_Finish(ESYS_CONTEXT * esysContext,TPM2B_ECC_POINT ** outZ1,TPM2B_ECC_POINT ** outZ2)257 Esys_ZGen_2Phase_Finish(
258     ESYS_CONTEXT *esysContext,
259     TPM2B_ECC_POINT **outZ1,
260     TPM2B_ECC_POINT **outZ2)
261 {
262     TSS2_RC r;
263     LOG_TRACE("context=%p, outZ1=%p, outZ2=%p",
264               esysContext, outZ1, outZ2);
265 
266     if (esysContext == NULL) {
267         LOG_ERROR("esyscontext is NULL.");
268         return TSS2_ESYS_RC_BAD_REFERENCE;
269     }
270 
271     /* Check for correct sequence and set sequence to irregular for now */
272     if (esysContext->state != _ESYS_STATE_SENT &&
273         esysContext->state != _ESYS_STATE_RESUBMISSION) {
274         LOG_ERROR("Esys called in bad sequence.");
275         return TSS2_ESYS_RC_BAD_SEQUENCE;
276     }
277     esysContext->state = _ESYS_STATE_INTERNALERROR;
278 
279     /* Allocate memory for response parameters */
280     if (outZ1 != NULL) {
281         *outZ1 = calloc(sizeof(TPM2B_ECC_POINT), 1);
282         if (*outZ1 == NULL) {
283             return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
284         }
285     }
286     if (outZ2 != NULL) {
287         *outZ2 = calloc(sizeof(TPM2B_ECC_POINT), 1);
288         if (*outZ2 == NULL) {
289             goto_error(r, TSS2_ESYS_RC_MEMORY, "Out of memory", error_cleanup);
290         }
291     }
292 
293     /*Receive the TPM response and handle resubmissions if necessary. */
294     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
295     if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN) {
296         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
297         esysContext->state = _ESYS_STATE_SENT;
298         goto error_cleanup;
299     }
300     /* This block handle the resubmission of TPM commands given a certain set of
301      * TPM response codes. */
302     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
303         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
304             "resubmission: %" PRIx32, r);
305         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
306             LOG_WARNING("Maximum number of (re)submissions has been reached.");
307             esysContext->state = _ESYS_STATE_INIT;
308             goto error_cleanup;
309         }
310         esysContext->state = _ESYS_STATE_RESUBMISSION;
311         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
312         if (r != TSS2_RC_SUCCESS) {
313             LOG_WARNING("Error attempting to resubmit");
314             /* We do not set esysContext->state here but inherit the most recent
315              * state of the _async function. */
316             goto error_cleanup;
317         }
318         r = TSS2_ESYS_RC_TRY_AGAIN;
319         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
320         goto error_cleanup;
321     }
322     /* The following is the "regular error" handling. */
323     if (iesys_tpm_error(r)) {
324         LOG_WARNING("Received TPM Error");
325         esysContext->state = _ESYS_STATE_INIT;
326         goto error_cleanup;
327     } else if (r != TSS2_RC_SUCCESS) {
328         LOG_ERROR("Received a non-TPM Error");
329         esysContext->state = _ESYS_STATE_INTERNALERROR;
330         goto error_cleanup;
331     }
332 
333     /*
334      * Now the verification of the response (hmac check) and if necessary the
335      * parameter decryption have to be done.
336      */
337     r = iesys_check_response(esysContext);
338     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
339                         error_cleanup);
340 
341     /*
342      * After the verification of the response we call the complete function
343      * to deliver the result.
344      */
345     r = Tss2_Sys_ZGen_2Phase_Complete(esysContext->sys,
346                                       (outZ1 != NULL) ? *outZ1 : NULL,
347                                       (outZ2 != NULL) ? *outZ2 : NULL);
348     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
349                         "Received error from SAPI unmarshaling" ,
350                         error_cleanup);
351 
352     esysContext->state = _ESYS_STATE_INIT;
353 
354     return TSS2_RC_SUCCESS;
355 
356 error_cleanup:
357     if (outZ1 != NULL)
358         SAFE_FREE(*outZ1);
359     if (outZ2 != NULL)
360         SAFE_FREE(*outZ2);
361 
362     return r;
363 }
364