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_GetRandom
23 *
24 * This function invokes the TPM2_GetRandom 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] bytesRequested Number of octets to return.
34 * @param[out] randomBytes The random octets.
35 * (callee-allocated)
36 * @retval TSS2_RC_SUCCESS if the function call was a success.
37 * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
38 * pointers or required output handle references are NULL.
39 * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
40 * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
41 * internal operations or return parameters.
42 * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
43 * operation already pending.
44 * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
45 * at least contain the tag, response length, and response code.
46 * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
47 * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM
48 did not verify.
49 * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
50 * the 'decrypt' attribute bit set.
51 * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
52 * the 'encrypt' attribute bit set.
53 * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
54 * 'decrypt' attribute set and the command does not support encryption
55 * of the first command parameter.
56 * @retval TSS2_RCs produced by lower layers of the software stack may be
57 * returned to the caller unaltered unless handled internally.
58 */
59 TSS2_RC
Esys_GetRandom(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,UINT16 bytesRequested,TPM2B_DIGEST ** randomBytes)60 Esys_GetRandom(
61 ESYS_CONTEXT *esysContext,
62 ESYS_TR shandle1,
63 ESYS_TR shandle2,
64 ESYS_TR shandle3,
65 UINT16 bytesRequested,
66 TPM2B_DIGEST **randomBytes)
67 {
68 TSS2_RC r;
69
70 r = Esys_GetRandom_Async(esysContext, shandle1, shandle2, shandle3,
71 bytesRequested);
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_GetRandom_Finish(esysContext, randomBytes);
86 /* This is just debug information about the reattempt to finish the
87 command */
88 if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN)
89 LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32
90 " => resubmitting command", r);
91 } while ((r & ~TSS2_RC_LAYER_MASK) == 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_GetRandom
101 *
102 * This function invokes the TPM2_GetRandom 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_GetRandom_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 * @param[in] bytesRequested Number of octets to return.
112 * @retval ESYS_RC_SUCCESS if the function call was a success.
113 * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
114 * pointers or required output handle references are NULL.
115 * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
116 * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
117 * internal operations or return parameters.
118 * @retval TSS2_RCs produced by lower layers of the software stack may be
119 returned to the caller unaltered unless handled internally.
120 * @retval TSS2_ESYS_RC_MULTIPLE_DECRYPT_SESSIONS: if more than one session has
121 * the 'decrypt' attribute bit set.
122 * @retval TSS2_ESYS_RC_MULTIPLE_ENCRYPT_SESSIONS: if more than one session has
123 * the 'encrypt' attribute bit set.
124 * @retval TSS2_ESYS_RC_NO_DECRYPT_PARAM: if one of the sessions has the
125 * 'decrypt' attribute set and the command does not support encryption
126 * of the first command parameter.
127 */
128 TSS2_RC
Esys_GetRandom_Async(ESYS_CONTEXT * esysContext,ESYS_TR shandle1,ESYS_TR shandle2,ESYS_TR shandle3,UINT16 bytesRequested)129 Esys_GetRandom_Async(
130 ESYS_CONTEXT *esysContext,
131 ESYS_TR shandle1,
132 ESYS_TR shandle2,
133 ESYS_TR shandle3,
134 UINT16 bytesRequested)
135 {
136 TSS2_RC r;
137 LOG_TRACE("context=%p, bytesRequested=%04"PRIx16"",
138 esysContext, bytesRequested);
139 TSS2L_SYS_AUTH_COMMAND auths;
140
141 /* Check context, sequence correctness and set state to error for now */
142 if (esysContext == NULL) {
143 LOG_ERROR("esyscontext is NULL.");
144 return TSS2_ESYS_RC_BAD_REFERENCE;
145 }
146 r = iesys_check_sequence_async(esysContext);
147 if (r != TSS2_RC_SUCCESS)
148 return r;
149 esysContext->state = _ESYS_STATE_INTERNALERROR;
150
151 /* Check input parameters */
152 r = check_session_feasibility(shandle1, shandle2, shandle3, 0);
153 return_state_if_error(r, _ESYS_STATE_INIT, "Check session usage");
154
155 /* Initial invocation of SAPI to prepare the command buffer with parameters */
156 r = Tss2_Sys_GetRandom_Prepare(esysContext->sys, bytesRequested);
157 return_state_if_error(r, _ESYS_STATE_INIT, "SAPI Prepare returned error.");
158
159 /* Calculate the cpHash Values */
160 r = init_session_tab(esysContext, shandle1, shandle2, shandle3);
161 return_state_if_error(r, _ESYS_STATE_INIT, "Initialize session resources");
162 iesys_compute_session_value(esysContext->session_tab[0], NULL, NULL);
163 iesys_compute_session_value(esysContext->session_tab[1], NULL, NULL);
164 iesys_compute_session_value(esysContext->session_tab[2], NULL, NULL);
165
166 /* Generate the auth values and set them in the SAPI command buffer */
167 r = iesys_gen_auths(esysContext, NULL, NULL, NULL, &auths);
168 return_state_if_error(r, _ESYS_STATE_INIT,
169 "Error in computation of auth values");
170
171 esysContext->authsCount = auths.count;
172 if (auths.count > 0) {
173 r = Tss2_Sys_SetCmdAuths(esysContext->sys, &auths);
174 return_state_if_error(r, _ESYS_STATE_INIT, "SAPI error on SetCmdAuths");
175 }
176
177 /* Trigger execution and finish the async invocation */
178 r = Tss2_Sys_ExecuteAsync(esysContext->sys);
179 return_state_if_error(r, _ESYS_STATE_INTERNALERROR,
180 "Finish (Execute Async)");
181
182 esysContext->state = _ESYS_STATE_SENT;
183
184 return r;
185 }
186
187 /** Asynchronous finish function for TPM2_GetRandom
188 *
189 * This function returns the results of a TPM2_GetRandom command
190 * invoked via Esys_GetRandom_Finish. All non-simple output parameters
191 * are allocated by the function's implementation. NULL can be passed for every
192 * output parameter if the value is not required.
193 *
194 * @param[in,out] esysContext The ESYS_CONTEXT.
195 * @param[out] randomBytes The random octets.
196 * (callee-allocated)
197 * @retval TSS2_RC_SUCCESS on success
198 * @retval ESYS_RC_SUCCESS if the function call was a success.
199 * @retval TSS2_ESYS_RC_BAD_REFERENCE if the esysContext or required input
200 * pointers or required output handle references are NULL.
201 * @retval TSS2_ESYS_RC_BAD_CONTEXT: if esysContext corruption is detected.
202 * @retval TSS2_ESYS_RC_MEMORY: if the ESAPI cannot allocate enough memory for
203 * internal operations or return parameters.
204 * @retval TSS2_ESYS_RC_BAD_SEQUENCE: if the context has an asynchronous
205 * operation already pending.
206 * @retval TSS2_ESYS_RC_TRY_AGAIN: if the timeout counter expires before the
207 * TPM response is received.
208 * @retval TSS2_ESYS_RC_INSUFFICIENT_RESPONSE: if the TPM's response does not
209 * at least contain the tag, response length, and response code.
210 * @retval TSS2_ESYS_RC_RSP_AUTH_FAILED: if the response HMAC from the TPM did
211 * not verify.
212 * @retval TSS2_ESYS_RC_MALFORMED_RESPONSE: if the TPM's response is corrupted.
213 * @retval TSS2_RCs produced by lower layers of the software stack may be
214 * returned to the caller unaltered unless handled internally.
215 */
216 TSS2_RC
Esys_GetRandom_Finish(ESYS_CONTEXT * esysContext,TPM2B_DIGEST ** randomBytes)217 Esys_GetRandom_Finish(
218 ESYS_CONTEXT *esysContext,
219 TPM2B_DIGEST **randomBytes)
220 {
221 TSS2_RC r;
222 LOG_TRACE("context=%p, randomBytes=%p",
223 esysContext, randomBytes);
224
225 if (esysContext == NULL) {
226 LOG_ERROR("esyscontext is NULL.");
227 return TSS2_ESYS_RC_BAD_REFERENCE;
228 }
229
230 /* Check for correct sequence and set sequence to irregular for now */
231 if (esysContext->state != _ESYS_STATE_SENT &&
232 esysContext->state != _ESYS_STATE_RESUBMISSION) {
233 LOG_ERROR("Esys called in bad sequence.");
234 return TSS2_ESYS_RC_BAD_SEQUENCE;
235 }
236 esysContext->state = _ESYS_STATE_INTERNALERROR;
237
238 /* Allocate memory for response parameters */
239 if (randomBytes != NULL) {
240 *randomBytes = calloc(sizeof(TPM2B_DIGEST), 1);
241 if (*randomBytes == NULL) {
242 return_error(TSS2_ESYS_RC_MEMORY, "Out of memory");
243 }
244 }
245
246 /*Receive the TPM response and handle resubmissions if necessary. */
247 r = Tss2_Sys_ExecuteFinish(esysContext->sys, esysContext->timeout);
248 if ((r & ~TSS2_RC_LAYER_MASK) == TSS2_BASE_RC_TRY_AGAIN) {
249 LOG_DEBUG("A layer below returned TRY_AGAIN: %" PRIx32, r);
250 esysContext->state = _ESYS_STATE_SENT;
251 goto error_cleanup;
252 }
253 /* This block handle the resubmission of TPM commands given a certain set of
254 * TPM response codes. */
255 if (r == TPM2_RC_RETRY || r == TPM2_RC_TESTING || r == TPM2_RC_YIELDED) {
256 LOG_DEBUG("TPM returned RETRY, TESTING or YIELDED, which triggers a "
257 "resubmission: %" PRIx32, r);
258 if (esysContext->submissionCount++ >= _ESYS_MAX_SUBMISSIONS) {
259 LOG_WARNING("Maximum number of (re)submissions has been reached.");
260 esysContext->state = _ESYS_STATE_INIT;
261 goto error_cleanup;
262 }
263 esysContext->state = _ESYS_STATE_RESUBMISSION;
264 r = Tss2_Sys_ExecuteAsync(esysContext->sys);
265 if (r != TSS2_RC_SUCCESS) {
266 LOG_WARNING("Error attempting to resubmit");
267 /* We do not set esysContext->state here but inherit the most recent
268 * state of the _async function. */
269 goto error_cleanup;
270 }
271 r = TSS2_ESYS_RC_TRY_AGAIN;
272 LOG_DEBUG("Resubmission initiated and returning RC_TRY_AGAIN.");
273 goto error_cleanup;
274 }
275 /* The following is the "regular error" handling. */
276 if (iesys_tpm_error(r)) {
277 LOG_WARNING("Received TPM Error");
278 esysContext->state = _ESYS_STATE_INIT;
279 goto error_cleanup;
280 } else if (r != TSS2_RC_SUCCESS) {
281 LOG_ERROR("Received a non-TPM Error");
282 esysContext->state = _ESYS_STATE_INTERNALERROR;
283 goto error_cleanup;
284 }
285
286 /*
287 * Now the verification of the response (hmac check) and if necessary the
288 * parameter decryption have to be done.
289 */
290 r = iesys_check_response(esysContext);
291 goto_state_if_error(r, _ESYS_STATE_INTERNALERROR, "Error: check response",
292 error_cleanup);
293
294 /*
295 * After the verification of the response we call the complete function
296 * to deliver the result.
297 */
298 r = Tss2_Sys_GetRandom_Complete(esysContext->sys,
299 (randomBytes != NULL) ? *randomBytes
300 : NULL);
301 goto_state_if_error(r, _ESYS_STATE_INTERNALERROR,
302 "Received error from SAPI unmarshaling" ,
303 error_cleanup);
304
305 esysContext->state = _ESYS_STATE_INIT;
306
307 return TSS2_RC_SUCCESS;
308
309 error_cleanup:
310 if (randomBytes != NULL)
311 SAFE_FREE(*randomBytes);
312
313 return r;
314 }
315