Files
xen/stubdom/vtpm/vtpm.c
T
Daniel De Graaf c1fe4dcf3f vtpm: passthru requests to manager
When sending commands to a vTPM, commands with the VTPM_TAG_REQ2 tag are
passed directly to the TPM Manager since they are used in the management
interface to the TPM Manager. The VTPM_TAG_REQ tag is translated to
TPM_TAG_RQU_COMMAND to allow access to the physical TPM for certain
ordinals (PCRRead, Extend, and GetRandom).

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2014-04-23 11:57:53 +01:00

505 lines
14 KiB
C

/*
* Copyright (c) 2010-2012 United States Government, as represented by
* the Secretary of Defense. All rights reserved.
*
* THIS SOFTWARE AND ITS DOCUMENTATION ARE PROVIDED AS IS AND WITHOUT
* ANY EXPRESS OR IMPLIED WARRANTIES WHATSOEVER. ALL WARRANTIES
* INCLUDING, BUT NOT LIMITED TO, PERFORMANCE, MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT ARE HEREBY
* DISCLAIMED. USERS ASSUME THE ENTIRE RISK AND LIABILITY OF USING THE
* SOFTWARE.
*/
#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <stdbool.h>
#include <errno.h>
#include <sys/time.h>
#include <xen/xen.h>
#include <tpmback.h>
#include <tpmfront.h>
#include <polarssl/entropy.h>
#include <polarssl/ctr_drbg.h>
#include "tpm/tpm_emulator_extern.h"
#include "tpm/tpm_marshalling.h"
#include "vtpm.h"
#include "vtpm_cmd.h"
#include "vtpm_pcrs.h"
#include "vtpmblk.h"
#include "vtpm_manager.h"
#define TPM_LOG_INFO LOG_INFO
#define TPM_LOG_ERROR LOG_ERR
#define TPM_LOG_DEBUG LOG_DEBUG
/* Global commandline options - default values */
struct Opt_args opt_args = {
.startup = ST_CLEAR,
.loglevel = TPM_LOG_INFO,
.hwinitpcrs = VTPM_PCRNONE,
.tpmconf = 0,
.enable_maint_cmds = false,
};
static uint32_t badords[32];
static unsigned int n_badords = 0;
entropy_context entropy;
ctr_drbg_context ctr_drbg;
struct tpmfront_dev* tpmfront_dev;
void vtpm_get_extern_random_bytes(void *buf, size_t nbytes)
{
ctr_drbg_random(&ctr_drbg, buf, nbytes);
}
int vtpm_read_from_file(uint8_t **data, size_t *data_length) {
return read_vtpmblk(tpmfront_dev, data, data_length);
}
int vtpm_write_to_file(uint8_t *data, size_t data_length) {
return write_vtpmblk(tpmfront_dev, data, data_length);
}
int vtpm_extern_init_fake(void) {
return 0;
}
void vtpm_extern_release_fake(void) {
}
void vtpm_log(int priority, const char *fmt, ...)
{
if(opt_args.loglevel >= priority) {
va_list v;
va_start(v, fmt);
vprintf(fmt, v);
va_end(v);
}
}
static uint64_t vtpm_get_ticks(void)
{
static uint64_t old_t = 0;
uint64_t new_t, res_t;
struct timeval tv;
gettimeofday(&tv, NULL);
new_t = (uint64_t)tv.tv_sec * 1000000 + (uint64_t)tv.tv_usec;
res_t = (old_t > 0) ? new_t - old_t : 0;
old_t = new_t;
return res_t;
}
static int tpm_entropy_source(void* dummy, unsigned char* data, size_t len, size_t* olen) {
UINT32 sz = len;
TPM_RESULT rc = VTPM_GetRandom(tpmfront_dev, data, &sz);
*olen = sz;
return rc == TPM_SUCCESS ? 0 : POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
}
int init_random(void) {
/* Initialize the rng */
entropy_init(&entropy);
entropy_add_source(&entropy, tpm_entropy_source, NULL, 0);
entropy_gather(&entropy);
ctr_drbg_init(&ctr_drbg, entropy_func, &entropy, NULL, 0);
ctr_drbg_set_prediction_resistance( &ctr_drbg, CTR_DRBG_PR_OFF );
return 0;
}
int check_passthru(tpmcmd_t* tpmcmd) {
TPM_TAG tag;
UINT32 len = 10;
BYTE* ptr;
size_t size;
if(tpmcmd->req_len < 10) {
return false;
}
ptr = tpmcmd->req;
tpm_unmarshal_UINT16(&ptr, &len, &tag);
if (tag == VTPM_TAG_REQ2) {
info("VTPM passthru: %d bytes", (int)tpmcmd->req_len);
tpmfront_cmd(tpmfront_dev, tpmcmd->req, tpmcmd->req_len, &tpmcmd->resp, &size);
tpmcmd->resp_len = size;
info("VTPM passthru return: %d bytes", (int)size);
return true;
}
if (tag == VTPM_TAG_REQ) {
info("VTPM pTPM-cmd: %d bytes", (int)tpmcmd->req_len);
ptr = tpmcmd->req;
tpm_marshal_UINT16(&ptr, &len, TPM_TAG_RQU_COMMAND);
tpmfront_cmd(tpmfront_dev, tpmcmd->req, tpmcmd->req_len, &tpmcmd->resp, &size);
tpmcmd->resp_len = size;
info("VTPM pTPM-cmd return: %d bytes", (int)size);
return true;
}
return false;
}
int check_ordinal(tpmcmd_t* tpmcmd) {
TPM_COMMAND_CODE ord;
UINT32 len = 4;
BYTE* ptr;
unsigned int i;
if(tpmcmd->req_len < 10) {
return true;
}
ptr = tpmcmd->req + 6;
tpm_unmarshal_UINT32(&ptr, &len, &ord);
for(i = 0; i < n_badords; ++i) {
if(ord == badords[i]) {
error("Disabled command ordinal (%" PRIu32") requested!\n");
return false;
}
}
return true;
}
struct locality_item {
char* lbl;
uint8_t mask[32];
};
#define MAX_CLIENT_LOCALITIES 16
static struct locality_item client_locality[MAX_CLIENT_LOCALITIES];
static int nr_client_localities = 0;
static void *generate_locality_mask(domid_t domid, unsigned int handle)
{
char label[512];
int i;
if (tpmback_get_peercontext(domid, handle, label, sizeof(label)))
BUG();
for(i=0; i < nr_client_localities; i++) {
if (!strcmp(client_locality[i].lbl, label))
goto found;
if (client_locality[i].lbl[0] == '*') {
char * f = strstr(label, 1 + client_locality[i].lbl);
if (!strcmp(f, 1 + client_locality[i].lbl))
goto found;
}
}
return NULL;
found:
tpmback_set_opaque(domid, handle, client_locality[i].mask);
return client_locality[i].mask;
}
static void main_loop(void) {
tpmcmd_t* tpmcmd = NULL;
int res = -1;
info("VTPM Initializing\n");
/* Set required tpm config args */
opt_args.tpmconf |= TPM_CONF_STRONG_PERSISTENCE;
opt_args.tpmconf &= ~TPM_CONF_USE_INTERNAL_PRNG;
opt_args.tpmconf |= TPM_CONF_GENERATE_EK;
opt_args.tpmconf |= TPM_CONF_GENERATE_SEED_DAA;
/* Initialize the emulator */
tpm_emulator_init(opt_args.startup, opt_args.tpmconf);
/* Initialize any requested PCRs with hardware TPM values */
if(vtpm_initialize_hw_pcrs(tpmfront_dev, opt_args.hwinitpcrs) != TPM_SUCCESS) {
error("Failed to initialize PCRs with hardware TPM values");
goto abort_postpcrs;
}
tpmcmd = tpmback_req_any();
while(tpmcmd) {
/* Handle the request */
if(tpmcmd->req_len) {
uint8_t* locality_mask = tpmcmd->opaque;
uint8_t locality_bit = (1 << (tpmcmd->locality & 7));
int locality_byte = tpmcmd->locality >> 3;
tpmcmd->resp = NULL;
tpmcmd->resp_len = 0;
if (nr_client_localities && !locality_mask)
locality_mask = generate_locality_mask(tpmcmd->domid, tpmcmd->handle);
if (nr_client_localities && !locality_mask) {
error("Unknown client label in tpm_handle_command");
create_error_response(tpmcmd, TPM_FAIL);
}
else if (nr_client_localities && !(locality_mask[locality_byte] & locality_bit)) {
error("Invalid locality (%d) for client in tpm_handle_command", tpmcmd->locality);
create_error_response(tpmcmd, TPM_FAIL);
}
/* Check for TPM Manager passthrough command */
else if(check_passthru(tpmcmd)) {
}
/* Check for disabled ordinals */
else if(!check_ordinal(tpmcmd)) {
create_error_response(tpmcmd, TPM_BAD_ORDINAL);
}
/* If not disabled, do the command */
else {
if((res = tpm_handle_command(tpmcmd->req, tpmcmd->req_len, &tpmcmd->resp, &tpmcmd->resp_len, tpmcmd->locality)) != 0) {
error("tpm_handle_command() failed");
create_error_response(tpmcmd, TPM_FAIL);
}
}
}
/* Send the response */
tpmback_resp(tpmcmd);
/* Wait for the next request */
tpmcmd = tpmback_req_any();
}
abort_postpcrs:
info("VTPM Shutting down");
tpm_emulator_shutdown();
}
int parse_cmd_line(int argc, char** argv)
{
char sval[25];
char* logstr = NULL;
/* Parse the command strings */
for(unsigned int i = 1; i < argc; ++i) {
if (sscanf(argv[i], "loglevel=%25s", sval) == 1){
if (!strcmp(sval, "debug")) {
opt_args.loglevel = TPM_LOG_DEBUG;
logstr = "debug";
}
else if (!strcmp(sval, "info")) {
logstr = "info";
opt_args.loglevel = TPM_LOG_INFO;
}
else if (!strcmp(sval, "error")) {
logstr = "error";
opt_args.loglevel = TPM_LOG_ERROR;
}
}
else if (!strcmp(argv[i], "clear")) {
opt_args.startup = ST_CLEAR;
}
else if (!strcmp(argv[i], "save")) {
opt_args.startup = ST_SAVE;
}
else if (!strcmp(argv[i], "deactivated")) {
opt_args.startup = ST_DEACTIVATED;
}
else if (!strncmp(argv[i], "maintcmds=", 10)) {
if(!strcmp(argv[i] + 10, "1")) {
opt_args.enable_maint_cmds = true;
} else if(!strcmp(argv[i] + 10, "0")) {
opt_args.enable_maint_cmds = false;
}
}
else if(!strncmp(argv[i], "hwinitpcr=", 10)) {
char *pch = argv[i] + 10;
unsigned int v1, v2;
pch = strtok(pch, ",");
while(pch != NULL) {
if(!strcmp(pch, "all")) {
//Set all
opt_args.hwinitpcrs = VTPM_PCRALL;
} else if(!strcmp(pch, "none")) {
//Set none
opt_args.hwinitpcrs = VTPM_PCRNONE;
} else if(sscanf(pch, "%u", &v1) == 1) {
//Set one
if(v1 >= TPM_NUM_PCR) {
error("hwinitpcr error: Invalid PCR index %u", v1);
return -1;
}
opt_args.hwinitpcrs |= (1 << v1);
} else if(sscanf(pch, "%u-%u", &v1, &v2) == 2) {
//Set range
if(v1 >= TPM_NUM_PCR) {
error("hwinitpcr error: Invalid PCR index %u", v1);
return -1;
}
if(v2 >= TPM_NUM_PCR) {
error("hwinitpcr error: Invalid PCR index %u", v1);
return -1;
}
if(v2 < v1) {
unsigned tp = v1;
v1 = v2;
v2 = tp;
}
for(unsigned int i = v1; i <= v2; ++i) {
opt_args.hwinitpcrs |= (1 << i);
}
} else {
error("hwintipcr error: Invalid PCR specification : %s", pch);
return -1;
}
pch = strtok(NULL, ",");
}
}
else if(!strncmp(argv[i], "locality=", 9)) {
char *lbl = argv[i] + 9;
char *pch = strchr(lbl, '=');
uint8_t* locality_mask = client_locality[nr_client_localities].mask;
if (pch == NULL) {
error("Invalid locality specification: %s", lbl);
return -1;
}
if (nr_client_localities == MAX_CLIENT_LOCALITIES) {
error("Too many locality specifications");
return -1;
}
client_locality[nr_client_localities].lbl = lbl;
memset(locality_mask, 0, 32);
nr_client_localities++;
*pch = 0;
pch = strtok(pch + 1, ",");
while (pch != NULL) {
unsigned int loc;
if (sscanf(pch, "%u", &loc) == 1 && loc < 256) {
uint8_t locality_bit = (1 << (loc & 7));
int locality_byte = loc >> 3;
locality_mask[locality_byte] |= locality_bit;
} else {
error("Invalid locality item: %s", pch);
return -1;
}
pch = strtok(NULL, ",");
}
}
else {
error("Invalid command line option `%s'", argv[i]);
}
}
/* Check Errors and print results */
switch(opt_args.startup) {
case ST_CLEAR:
info("Startup mode is `clear'");
break;
case ST_SAVE:
info("Startup mode is `save'");
break;
case ST_DEACTIVATED:
info("Startup mode is `deactivated'");
break;
default:
error("Invalid startup mode %d", opt_args.startup);
return -1;
}
if(opt_args.hwinitpcrs & (VTPM_PCRALL))
{
char pcrstr[1024];
char* ptr = pcrstr;
pcrstr[0] = '\0';
info("The following PCRs will be initialized with values from the hardware TPM:");
for(unsigned int i = 0; i < TPM_NUM_PCR; ++i) {
if(opt_args.hwinitpcrs & (1 << i)) {
ptr += sprintf(ptr, "%u, ", i);
}
}
/* get rid of the last comma if any numbers were printed */
*(ptr -2) = '\0';
info("\t%s", pcrstr);
} else {
info("All PCRs initialized to default values");
}
if(!opt_args.enable_maint_cmds) {
info("TPM Maintenance Commands disabled");
badords[n_badords++] = TPM_ORD_CreateMaintenanceArchive;
badords[n_badords++] = TPM_ORD_LoadMaintenanceArchive;
badords[n_badords++] = TPM_ORD_KillMaintenanceFeature;
badords[n_badords++] = TPM_ORD_LoadManuMaintPub;
badords[n_badords++] = TPM_ORD_ReadManuMaintPub;
} else {
info("TPM Maintenance Commands enabled");
}
info("Log level set to %s", logstr);
return 0;
}
void cleanup_opt_args(void) {
}
int main(int argc, char **argv)
{
//FIXME: initializing blkfront without this sleep causes the domain to crash on boot
sleep(2);
/* Setup extern function pointers */
tpm_extern_init = vtpm_extern_init_fake;
tpm_extern_release = vtpm_extern_release_fake;
tpm_malloc = malloc;
tpm_free = free;
tpm_log = vtpm_log;
tpm_get_ticks = vtpm_get_ticks;
tpm_get_extern_random_bytes = vtpm_get_extern_random_bytes;
tpm_write_to_storage = vtpm_write_to_file;
tpm_read_from_storage = vtpm_read_from_file;
info("starting TPM Emulator (1.2.%d.%d-%d)", VERSION_MAJOR, VERSION_MINOR, VERSION_BUILD);
if(parse_cmd_line(argc, argv)) {
error("Error parsing commandline\n");
return -1;
}
/* Initialize devices */
init_tpmback(NULL, NULL);
if((tpmfront_dev = init_tpmfront(NULL)) == NULL) {
error("Unable to initialize tpmfront device");
goto abort_posttpmfront;
}
/* Seed the RNG with entropy from hardware TPM */
if(init_random()) {
error("Unable to initialize RNG");
goto abort_postrng;
}
/* Initialize blkfront device */
if(init_vtpmblk(tpmfront_dev)) {
error("Unable to initialize Blkfront persistent storage");
goto abort_postvtpmblk;
}
/* Run main loop */
main_loop();
/* Shutdown blkfront */
shutdown_vtpmblk();
abort_postvtpmblk:
abort_postrng:
/* Close devices */
shutdown_tpmfront(tpmfront_dev);
abort_posttpmfront:
shutdown_tpmback();
cleanup_opt_args();
return 0;
}