wolfTPM/examples/attestation/activate_credential.c

248 lines
7.9 KiB
C

/* activate_credential.c
*
* Copyright (C) 2006-2025 wolfSSL Inc.
*
* This file is part of wolfTPM.
*
* wolfTPM is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* wolfTPM is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
*/
/* This example shows how to decrypt a credential for Remote Attestation
* and extract the secret for challenge response to an attestation server
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <wolftpm/tpm2_wrap.h>
#include <stdio.h>
#ifndef WOLFTPM2_NO_WRAPPER
#include <examples/attestation/attestation.h>
#include <hal/tpm_io.h>
#include <examples/tpm_test.h>
#include <examples/tpm_test_keys.h>
/******************************************************************************/
/* --- BEGIN TPM2.0 Activate Credential example tool -- */
/******************************************************************************/
static void usage(void)
{
printf("Expected usage:\n");
printf("./examples/attestation/activate_credential [cred.blob] [-eh]\n");
printf("* cred.blob is a input file holding the generated credential.\n");
printf("* -eh: Use the EK public key to encrypt the challenge\n");
printf("Demo usage without parameters, uses \"cred.blob\" filename.\n");
}
int TPM2_ActivateCredential_Example(void* userCtx, int argc, char *argv[])
{
int rc = -1;
int endorseKey = 0;
WOLFTPM2_DEV dev;
WOLFTPM2_KEY endorse;
WOLFTPM2_KEY storage;
WOLFTPM2_KEY *primary = NULL;
WOLFTPM2_KEYBLOB akKey;
WOLFTPM2_SESSION tpmSession;
#if !defined(NO_FILESYSTEM) && !defined(NO_WRITE_TEMP_FILES)
FILE *fp;
int dataSize = 0;
#endif
const char *input = "cred.blob";
const char *keyblob = "keyblob.bin";
ActivateCredential_In activCredIn;
ActivateCredential_Out activCredOut;
if (argc == 1) {
printf("Using default values\n");
}
else if (argc == 2) {
if (XSTRCMP(argv[1], "-?") == 0 ||
XSTRCMP(argv[1], "-h") == 0 ||
XSTRCMP(argv[1], "--help") == 0) {
usage();
return 0;
}
if (argv[1][0] != '-') {
input = argv[1];
}
if (XSTRCMP(argv[1], "-eh") == 0) {
printf("Use Endorsement Key\n");
endorseKey = 1;
}
}
else {
printf("Incorrect arguments\n");
usage();
goto exit_badargs;
}
XMEMSET(&endorse, 0, sizeof(endorse));
XMEMSET(&storage, 0, sizeof(storage));
XMEMSET(&akKey, 0, sizeof(akKey));
printf("Demo how to create a credential blob for remote attestation\n");
rc = wolfTPM2_Init(&dev, TPM2_IoCb, userCtx);
if (rc != TPM_RC_SUCCESS) {
printf("wolfTPM2_Init failed 0x%x: %s\n", rc, TPM2_GetRCString(rc));
goto exit;
}
printf("wolfTPM2_Init: success\n");
printf("Credential will be read from %s\n", input);
/* Load key, required to unwrap credential */
if (endorseKey) {
rc = wolfTPM2_CreateEK(&dev, &endorse, TPM_ALG_RSA);
if (rc != 0) goto exit;
printf("EK loaded\n");
/* Endorsement Key requires authorization with Policy */
endorse.handle.policyAuth = 1;
rc = wolfTPM2_CreateAuthSession_EkPolicy(&dev, &tpmSession);
if (rc != 0) goto exit;
/* Set the created Policy Session for use in next operation */
rc = wolfTPM2_SetAuthSession(&dev, 0, &tpmSession, 0);
if (rc != 0) goto exit;
primary = &endorse;
}
else {
rc = getPrimaryStoragekey(&dev, &storage, TPM_ALG_RSA);
if (rc != 0) goto exit;
printf("SRK loaded\n");
wolfTPM2_SetAuthHandle(&dev, 0, &storage.handle);
primary = &storage;
}
/* Load AK, required to verify the Key Attributes in the credential */
rc = readKeyBlob(keyblob, &akKey);
if (rc != TPM_RC_SUCCESS) {
printf("Failure to read keyblob.\n");
}
rc = wolfTPM2_LoadKey(&dev, &akKey, &primary->handle);
if (rc != TPM_RC_SUCCESS) {
printf("Failure to load the AK and read its Name.\n");
goto exit;
}
printf("AK loaded at 0x%x\n", (word32)akKey.handle.hndl);
rc = wolfTPM2_UnsetAuth(&dev, 0);
if (rc != 0) goto exit;
if (endorseKey) {
/* Fresh policy session for EK auth */
rc = wolfTPM2_CreateAuthSession_EkPolicy(&dev, &tpmSession);
if (rc != 0) goto exit;
/* Set the created Policy Session for use in next operation */
rc = wolfTPM2_SetAuthSession(&dev, 1, &tpmSession, 0);
if (rc != 0) goto exit;
/* Set the name for the endorsement handle */
rc = wolfTPM2_SetAuthHandleName(&dev, 1, &endorse.handle);
if (rc != 0) goto exit;
}
else {
rc = wolfTPM2_SetAuthHandle(&dev, 1, &storage.handle);
if (rc != 0) goto exit;
}
/* Prepare the auth password for the Attestation Key */
akKey.handle.auth.size = sizeof(gAiKeyAuth)-1;
XMEMCPY(akKey.handle.auth.buffer, gAiKeyAuth,
akKey.handle.auth.size);
wolfTPM2_SetAuthHandle(&dev, 0, &akKey.handle);
/* Prepare the Activate Credential command */
XMEMSET(&activCredIn, 0, sizeof(activCredIn));
XMEMSET(&activCredOut, 0, sizeof(activCredOut));
activCredIn.activateHandle = akKey.handle.hndl;
activCredIn.keyHandle = primary->handle.hndl;
/* Read credential from the user file */
#if !defined(NO_FILESYSTEM) && !defined(NO_WRITE_TEMP_FILES)
fp = XFOPEN(input, "rb");
if (fp != XBADFILE) {
dataSize = (int)XFREAD((BYTE*)&activCredIn.credentialBlob, 1,
sizeof(activCredIn.credentialBlob), fp);
if (dataSize > 0) {
dataSize += (int)XFREAD((BYTE*)&activCredIn.secret, 1,
sizeof(activCredIn.secret), fp);
}
XFCLOSE(fp);
}
printf("Read credential blob and secret from %s, %d bytes\n",
input, dataSize);
#else
printf("Can not load credential. File support not enabled\n");
goto exit;
#endif
/* All required data to verify the credential is prepared */
rc = TPM2_ActivateCredential(&activCredIn, &activCredOut);
if (rc != TPM_RC_SUCCESS) {
printf("TPM2_ActivateCredential failed 0x%x: %s\n", rc,
TPM2_GetRCString(rc));
goto exit;
}
printf("TPM2_ActivateCredential success\n");
if (endorseKey) {
/* The policy session is closed after use.
* Reset handle, so we don't try and free it */
tpmSession.handle.hndl = TPM_RH_NULL;
}
printf("Secret: %d\n", activCredOut.certInfo.size);
TPM2_PrintBin(activCredOut.certInfo.buffer,
activCredOut.certInfo.size);
exit:
wolfTPM2_UnloadHandle(&dev, &primary->handle);
wolfTPM2_UnloadHandle(&dev, &akKey.handle);
wolfTPM2_UnloadHandle(&dev, &tpmSession.handle);
wolfTPM2_Cleanup(&dev);
exit_badargs:
return rc;
}
/******************************************************************************/
/* --- END TPM2.0 Activate Credential example tool -- */
/******************************************************************************/
#endif /* !WOLFTPM2_NO_WRAPPER */
#ifndef NO_MAIN_DRIVER
int main(int argc, char *argv[])
{
int rc = -1;
#ifndef WOLFTPM2_NO_WRAPPER
rc = TPM2_ActivateCredential_Example(NULL, argc, argv);
#else
printf("Wrapper code not compiled in\n");
(void)argc;
(void)argv;
#endif /* !WOLFTPM2_NO_WRAPPER */
return rc;
}
#endif