• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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_Sign
23  *
24  * This function invokes the TPM2_Sign 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]  keyHandle Handle of key that will perform signing.
31  * @param[in]  shandle1 Session handle for authorization of keyHandle
32  * @param[in]  shandle2 Second session handle.
33  * @param[in]  shandle3 Third session handle.
34  * @param[in]  digest Digest to be signed.
35  * @param[in]  inScheme TPM2_Signing scheme to use if the scheme for keyHandle is
36  *             TPM2_ALG_NULL.
37  * @param[in]  validation Proof that digest was created by the TPM.
38  * @param[out] signature The signature.
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_ENCRYPT_PARAM: if one of the sessions has the
61  *         'encrypt' attribute set and the command does not support encryption
62  *          of the first response 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_Sign(ESYS_CONTEXT * esysContext,ESYS_TR keyHandle,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_DIGEST * digest,const TPMT_SIG_SCHEME * inScheme,const TPMT_TK_HASHCHECK * validation,TPMT_SIGNATURE ** signature)67 Esys_Sign(
68     ESYS_CONTEXT *esysContext,
69     ESYS_TR keyHandle,
70     ESYS_TR shandle1,
71     ESYS_TR shandle2,
72     ESYS_TR shandle3,
73     const TPM2B_DIGEST *digest,
74     const TPMT_SIG_SCHEME *inScheme,
75     const TPMT_TK_HASHCHECK *validation,
76     TPMT_SIGNATURE **signature)
77 {
78     TSS2_RC r;
79 
80     r = Esys_Sign_Async(esysContext, keyHandle, shandle1, shandle2, shandle3,
81                         digest, inScheme, validation);
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_Sign_Finish(esysContext, signature);
96         /* This is just debug information about the reattempt to finish the
97            command */
98         if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN)
99             LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
100                       " => resubmitting command", r);
101     } while ((r & ~TSS2_RC_LAYER_MASK) == 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_Sign
111  *
112  * This function invokes the TPM2_Sign 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_Sign_Finish.
116  *
117  * @param[in,out] esysContext The ESYS_CONTEXT.
118  * @param[in]  keyHandle Handle of key that will perform signing.
119  * @param[in]  shandle1 Session handle for authorization of keyHandle
120  * @param[in]  shandle2 Second session handle.
121  * @param[in]  shandle3 Third session handle.
122  * @param[in]  digest Digest to be signed.
123  * @param[in]  inScheme TPM2_Signing scheme to use if the scheme for keyHandle is
124  *             TPM2_ALG_NULL.
125  * @param[in]  validation Proof that digest was created by the TPM.
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_ENCRYPT_PARAM: if one of the sessions has the
142  *         'encrypt' attribute set and the command does not support encryption
143  *          of the first response parameter.
144  */
145 TSS2_RC
Esys_Sign_Async(ESYS_CONTEXT * esysContext,ESYS_TR keyHandle,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,const TPM2B_DIGEST * digest,const TPMT_SIG_SCHEME * inScheme,const TPMT_TK_HASHCHECK * validation)146 Esys_Sign_Async(
147     ESYS_CONTEXT *esysContext,
148     ESYS_TR keyHandle,
149     ESYS_TR shandle1,
150     ESYS_TR shandle2,
151     ESYS_TR shandle3,
152     const TPM2B_DIGEST *digest,
153     const TPMT_SIG_SCHEME *inScheme,
154     const TPMT_TK_HASHCHECK *validation)
155 {
156     TSS2_RC r;
157     LOG_TRACE("context=%p, keyHandle=%"PRIx32 ", digest=%p,"
158               "inScheme=%p, validation=%p",
159               esysContext, keyHandle, digest, inScheme, validation);
160     TSS2L_SYS_AUTH_COMMAND auths;
161     RSRC_NODE_T *keyHandleNode;
162 
163     /* Check context, sequence correctness and set state to error for now */
164     if (esysContext == NULL) {
165         LOG_ERROR("esyscontext is NULL.");
166         return TSS2_ESYS_RC_BAD_REFERENCE;
167     }
168     r = iesys_check_sequence_async(esysContext);
169     if (r != TSS2_RC_SUCCESS)
170         return r;
171     esysContext->state = _ESYS_STATE_INTERNALERROR;
172 
173     /* Check input parameters */
174     r = check_session_feasibility(shandle1, shandle2, shandle3, 1);
175     return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
176 
177     /* Retrieve the metadata objects for provided handles */
178     r = esys_GetResourceObject(esysContext, keyHandle, &keyHandleNode);
179     return_state_if_error(r, _ESYS_STATE_INIT, "keyHandle unknown.");
180 
181     /* Initial invocation of SAPI to prepare the command buffer with parameters */
182     r = Tss2_Sys_Sign_Prepare(esysContext->sys,
183                               (keyHandleNode == NULL) ? TPM2_RH_NULL
184                                : keyHandleNode->rsrc.handle, digest, inScheme,
185                               validation);
186     return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
187 
188     /* Calculate the cpHash Values */
189     r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
190     return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
191     if (keyHandleNode != NULL)
192        iesys_compute_session_value(esysContext->session_tab[0],
193                 &keyHandleNode->rsrc.name, &keyHandleNode->auth);
194     else
195         iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
196 
197     iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
198     iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
199 
200     /* Generate the auth values and set them in the SAPI command buffer */
201     r = iesys_gen_auths(esysContext, keyHandleNode, NULL, NULL, &auths);
202     return_state_if_error(r, _ESYS_STATE_INIT,
203                           "Error in computation of auth values");
204 
205     esysContext->authsCount = auths.count;
206     if (auths.count > 0) {
207         r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
208         return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
209     }
210 
211     /* Trigger execution and finish the async invocation */
212     r = Tss2_Sys_ExecuteAsync(esysContext->sys);
213     return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
214                           "Finish (Execute Async)");
215 
216     esysContext->state = _ESYS_STATE_SENT;
217 
218     return r;
219 }
220 
221 /** Asynchronous finish function for TPM2_Sign
222  *
223  * This function returns the results of a TPM2_Sign command
224  * invoked via Esys_Sign_Finish. All non-simple output parameters
225  * are allocated by the function's implementation. NULL can be passed for every
226  * output parameter if the value is not required.
227  *
228  * @param[in,out] esysContext The ESYS_CONTEXT.
229  * @param[out] signature The signature.
230  *             (callee-allocated)
231  * @retval TSS2_RC_SUCCESS on success
232  * @retval ESYS_RC_SUCCESS if the function call was a success.
233  * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
234  *         pointers or required output handle references are NULL.
235  * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
236  * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
237  *         internal operations or return parameters.
238  * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
239  *         operation already pending.
240  * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
241  *         TPM response is received.
242  * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
243  *         at least contain the tag, response length, and response code.
244  * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
245  *         not verify.
246  * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
247  * @retval TSS2_RCs produced by lower layers of the software stack may be
248  *         returned to the caller unaltered unless handled internally.
249  */
250 TSS2_RC
Esys_Sign_Finish(ESYS_CONTEXT * esysContext,TPMT_SIGNATURE ** signature)251 Esys_Sign_Finish(
252     ESYS_CONTEXT *esysContext,
253     TPMT_SIGNATURE **signature)
254 {
255     TSS2_RC r;
256     LOG_TRACE("context=%p, signature=%p",
257               esysContext, signature);
258 
259     if (esysContext == NULL) {
260         LOG_ERROR("esyscontext is NULL.");
261         return TSS2_ESYS_RC_BAD_REFERENCE;
262     }
263 
264     /* Check for correct sequence and set sequence to irregular for now */
265     if (esysContext->state != _ESYS_STATE_SENT &&
266         esysContext->state != _ESYS_STATE_RESUBMISSION) {
267         LOG_ERROR("Esys called in bad sequence.");
268         return TSS2_ESYS_RC_BAD_SEQUENCE;
269     }
270     esysContext->state = _ESYS_STATE_INTERNALERROR;
271 
272     /* Allocate memory for response parameters */
273     if (signature != NULL) {
274         *signature = calloc(sizeof(TPMT_SIGNATURE), 1);
275         if (*signature == NULL) {
276             return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
277         }
278     }
279 
280     /*Receive the TPM response and handle resubmissions if necessary. */
281     r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
282     if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN) {
283         LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
284         esysContext->state = _ESYS_STATE_SENT;
285         goto error_cleanup;
286     }
287     /* This block handle the resubmission of TPM commands given a certain set of
288      * TPM response codes. */
289     if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
290         LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
291             "resubmission: %" PRIx32, r);
292         if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
293             LOG_WARNING("Maximum number of (re)submissions has been reached.");
294             esysContext->state = _ESYS_STATE_INIT;
295             goto error_cleanup;
296         }
297         esysContext->state = _ESYS_STATE_RESUBMISSION;
298         r = Tss2_Sys_ExecuteAsync(esysContext->sys);
299         if (r != TSS2_RC_SUCCESS) {
300             LOG_WARNING("Error attempting to resubmit");
301             /* We do not set esysContext->state here but inherit the most recent
302              * state of the _async function. */
303             goto error_cleanup;
304         }
305         r = TSS2_ESYS_RC_TRY_AGAIN;
306         LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
307         goto error_cleanup;
308     }
309     /* The following is the "regular error" handling. */
310     if (iesys_tpm_error(r)) {
311         LOG_WARNING("Received TPM Error");
312         esysContext->state = _ESYS_STATE_INIT;
313         goto error_cleanup;
314     } else if (r != TSS2_RC_SUCCESS) {
315         LOG_ERROR("Received a non-TPM Error");
316         esysContext->state = _ESYS_STATE_INTERNALERROR;
317         goto error_cleanup;
318     }
319 
320     /*
321      * Now the verification of the response (hmac check) and if necessary the
322      * parameter decryption have to be done.
323      */
324     r = iesys_check_response(esysContext);
325     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
326                         error_cleanup);
327 
328     /*
329      * After the verification of the response we call the complete function
330      * to deliver the result.
331      */
332     r = Tss2_Sys_Sign_Complete(esysContext->sys,
333                                (signature != NULL) ? *signature : NULL);
334     goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
335                         "Received error from SAPI unmarshaling" ,
336                         error_cleanup);
337 
338     esysContext->state = _ESYS_STATE_INIT;
339 
340     return TSS2_RC_SUCCESS;
341 
342 error_cleanup:
343     if (signature != NULL)
344         SAFE_FREE(*signature);
345 
346     return r;
347 }
348