src/security/tpm/tss/tcg-1.2/tss.c

   1 /* SPDX-License-Identifier: BSD-3-Clause */
   2
   3 /*
   4  * A lightweight TPM command library.
   5  *
   6  * The general idea is that TPM commands are array of bytes whose
   7  * fields are mostly compile-time constant.  The goal is to build much
   8  * of the commands at compile time (or build time) and change some of
   9  * the fields at run time as needed.  The code in
  10  * utility/tlcl_generator.c builds structures containing the commands,
  11  * as well as the offsets of the fields that need to be set at run
  12  * time.
  13  */
  14
  15 #include <assert.h>
  16 #include <string.h>
  17 #include <security/tpm/tis.h>
  18 #include <vb2_api.h>
  19 #include <security/tpm/tss.h>
  20
  21 #include "tss_internal.h"
  22 #include "tss_commands.h"
  23
  24 #include <console/console.h>
  25 #define VBDEBUG(format, args...) printk(BIOS_DEBUG, format, ## args)
  26
  27 static tpm_result_t tpm_send_receive(const uint8_t *request,
  28                                      uint32_t request_length,
  29                                      uint8_t *response,
  30                                      uint32_t *response_length)
  31 {
  32         size_t len = *response_length;
  33         tpm_result_t rc;
  34
  35         if (tlcl_tis_sendrecv == NULL) {
  36                 printk(BIOS_ERR, "Attempted use of uninitialized TSS 1.2 stack\n");
  37                 return TPM_FAIL;
  38         }
  39
  40         rc = tlcl_tis_sendrecv(request, request_length, response, &len);
  41         if (rc)
  42                 return rc;
  43         /* check 64->32bit overflow and (re)check response buffer overflow */
  44         if (len > *response_length)
  45                 rc = TPM_CB_FAIL;
  46         else
  47                 *response_length = len;
  48         return rc;
  49 }
  50
  51 /* Sets the size field of a TPM command. */
  52 static inline void set_tpm_command_size(uint8_t *buffer, uint32_t size)
  53 {
  54         to_tpm_uint32(buffer + sizeof(uint16_t), size);
  55 }
  56
  57 /* Gets the size field of a TPM command. */
  58 __attribute__((unused))
  59 static inline int tpm_command_size(const uint8_t *buffer)
  60 {
  61         uint32_t size;
  62         from_tpm_uint32(buffer + sizeof(uint16_t), &size);
  63         return (int)size;
  64 }
  65
  66 /* Gets the code field of a TPM command. */
  67 static inline tpm_result_t tpm_command_code(const uint8_t *buffer)
  68 {
  69         tpm_result_t rc;
  70         from_tpm_uint32(buffer + sizeof(uint16_t) + sizeof(uint32_t), &rc);
  71         return rc;
  72 }
  73
  74 /* Gets the return code field of a TPM result. */
  75 static inline tpm_result_t tpm_return_code(const uint8_t *buffer)
  76 {
  77         return tpm_command_code(buffer);
  78 }
  79
  80 /*
  81  * Like TlclSendReceive below, but do not retry if NEEDS_SELFTEST or
  82  * DOING_SELFTEST errors are returned.
  83  */
  84 static tpm_result_t tlcl1_send_receive_no_retry(const uint8_t *request,
  85                                                 uint8_t *response, int max_length)
  86 {
  87         uint32_t response_length = max_length;
  88         tpm_result_t rc;
  89
  90         rc = tpm_send_receive(request, tpm_command_size(request),
  91                                         response, &response_length);
  92         if (rc != TPM_SUCCESS) {
  93                 /* Communication with TPM failed, so response is garbage */
  94                 VBDEBUG("TPM: command %#x send/receive failed: %#x\n",
  95                         tpm_command_code(request), rc);
  96                 return rc;
  97         }
  98         /* Otherwise, use the result code from the response */
  99         rc = tpm_return_code(response);
 100
 101         /* TODO: add paranoia about returned response_length vs. max_length
 102          * (and possibly expected length from the response header).  See
 103          * crosbug.com/17017 */
 104
 105         VBDEBUG("TPM: command %#x returned %#x\n",
 106                 tpm_command_code(request), rc);
 107
 108         return rc;
 109 }
 110
 111 /* Sends a TPM command and gets a response.  Returns 0 if success or the TPM
 112  * error code if error. Waits for the self test to complete if needed. */
 113 tpm_result_t tlcl1_send_receive(const uint8_t *request, uint8_t *response, int max_length)
 114 {
 115         tpm_result_t rc = tlcl1_send_receive_no_retry(request, response, max_length);
 116         /* If the command fails because the self test has not completed, try it
 117          * again after attempting to ensure that the self test has completed. */
 118         if (rc == TPM_NEEDS_SELFTEST || rc == TPM_DOING_SELFTEST) {
 119                 rc = tlcl1_continue_self_test();
 120                 if (rc != TPM_SUCCESS)
 121                         return rc;
 122 #if defined(TPM_BLOCKING_CONTINUESELFTEST) || defined(VB_RECOVERY_MODE)
 123                 /* Retry only once */
 124                 rc = tlcl1_send_receive_no_retry(request, response, max_length);
 125 #else
 126                 /* This needs serious testing. The TPM specification says: "iii.
 127                  * The caller MUST wait for the actions of TPM_ContinueSelfTest
 128                  * to complete before reissuing the command C1."  But, if
 129                  * ContinueSelfTest is non-blocking, how do we know that the
 130                  * actions have completed other than trying again? */
 131                 do {
 132                         rc = tlcl1_send_receive_no_retry(request, response, max_length);
 133                 } while (rc == TPM_DOING_SELFTEST);
 134 #endif
 135         }
 136         return rc;
 137 }
 138
 139 /* Sends a command and returns the error code. */
 140 static tpm_result_t send(const uint8_t *command)
 141 {
 142         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 143         return tlcl1_send_receive(command, response, sizeof(response));
 144 }
 145
 146 /* Exported functions. */
 147
 148 tpm_result_t tlcl1_startup(void)
 149 {
 150         VBDEBUG("TPM: Startup\n");
 151         return send(tpm_startup_cmd.buffer);
 152 }
 153
 154 tpm_result_t tlcl1_resume(void)
 155 {
 156         VBDEBUG("TPM: Resume\n");
 157         return send(tpm_resume_cmd.buffer);
 158 }
 159
 160 tpm_result_t tlcl1_save_state(void)
 161 {
 162         VBDEBUG("TPM: Save state\n");
 163         return send(tpm_savestate_cmd.buffer);
 164 }
 165
 166 tpm_result_t tlcl1_self_test_full(void)
 167 {
 168         VBDEBUG("TPM: Self test full\n");
 169         return send(tpm_selftestfull_cmd.buffer);
 170 }
 171
 172 tpm_result_t tlcl1_continue_self_test(void)
 173 {
 174         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 175         VBDEBUG("TPM: Continue self test\n");
 176         /* Call the No Retry version of SendReceive to avoid recursion. */
 177         return tlcl1_send_receive_no_retry(tpm_continueselftest_cmd.buffer,
 178                                            response, sizeof(response));
 179 }
 180
 181 tpm_result_t tlcl1_define_space(uint32_t index, uint32_t perm, uint32_t size)
 182 {
 183         struct s_tpm_nv_definespace_cmd cmd;
 184         VBDEBUG("TPM: TlclDefineSpace(%#x, %#x, %d)\n", index, perm, size);
 185         memcpy(&cmd, &tpm_nv_definespace_cmd, sizeof(cmd));
 186         to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.index, index);
 187         to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.perm, perm);
 188         to_tpm_uint32(cmd.buffer + tpm_nv_definespace_cmd.size, size);
 189         return send(cmd.buffer);
 190 }
 191
 192 tpm_result_t tlcl1_write(uint32_t index, const void *data, uint32_t length)
 193 {
 194         struct s_tpm_nv_write_cmd cmd;
 195         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 196         const int total_length =
 197                         kTpmRequestHeaderLength + kWriteInfoLength + length;
 198
 199         VBDEBUG("TPM: %s(%#x, %d)\n", __func__, index, length);
 200         memcpy(&cmd, &tpm_nv_write_cmd, sizeof(cmd));
 201         assert(total_length <= TPM_LARGE_ENOUGH_COMMAND_SIZE);
 202         set_tpm_command_size(cmd.buffer, total_length);
 203
 204         to_tpm_uint32(cmd.buffer + tpm_nv_write_cmd.index, index);
 205         to_tpm_uint32(cmd.buffer + tpm_nv_write_cmd.length, length);
 206         if (length > 0)
 207                 memcpy(cmd.buffer + tpm_nv_write_cmd.data, data, length);
 208
 209         return tlcl1_send_receive(cmd.buffer, response, sizeof(response));
 210 }
 211
 212 tpm_result_t tlcl1_read(uint32_t index, void *data, uint32_t length)
 213 {
 214         struct s_tpm_nv_read_cmd cmd;
 215         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 216         uint32_t result_length;
 217         tpm_result_t rc;
 218
 219         VBDEBUG("TPM: %s(%#x, %d)\n", __func__, index, length);
 220         memcpy(&cmd, &tpm_nv_read_cmd, sizeof(cmd));
 221         to_tpm_uint32(cmd.buffer + tpm_nv_read_cmd.index, index);
 222         to_tpm_uint32(cmd.buffer + tpm_nv_read_cmd.length, length);
 223
 224         rc = tlcl1_send_receive(cmd.buffer, response, sizeof(response));
 225         if (rc == TPM_SUCCESS && length > 0) {
 226                 uint8_t *nv_read_cursor = response + kTpmResponseHeaderLength;
 227                 from_tpm_uint32(nv_read_cursor, &result_length);
 228                 if (result_length > length)
 229                         return TPM_IOERROR;
 230                 nv_read_cursor += sizeof(uint32_t);
 231                 memcpy(data, nv_read_cursor, result_length);
 232         }
 233
 234         return rc;
 235 }
 236
 237 tpm_result_t tlcl1_assert_physical_presence(void)
 238 {
 239         VBDEBUG("TPM: Asserting physical presence\n");
 240         return send(tpm_ppassert_cmd.buffer);
 241 }
 242
 243 tpm_result_t tlcl1_physical_presence_cmd_enable(void)
 244 {
 245         VBDEBUG("TPM: Enable the physical presence command\n");
 246         return send(tpm_ppenable_cmd.buffer);
 247 }
 248
 249 tpm_result_t tlcl1_finalize_physical_presence(void)
 250 {
 251         VBDEBUG("TPM: Enable PP cmd, disable HW pp, and set lifetime lock\n");
 252         return send(tpm_finalizepp_cmd.buffer);
 253 }
 254
 255 tpm_result_t tlcl1_set_nv_locked(void)
 256 {
 257         VBDEBUG("TPM: Set NV locked\n");
 258         return tlcl1_define_space(TPM_NV_INDEX_LOCK, 0, 0);
 259 }
 260
 261 tpm_result_t tlcl1_force_clear(void)
 262 {
 263         VBDEBUG("TPM: Force clear\n");
 264         return send(tpm_forceclear_cmd.buffer);
 265 }
 266
 267 tpm_result_t tlcl1_set_enable(void)
 268 {
 269         VBDEBUG("TPM: Enabling TPM\n");
 270         return send(tpm_physicalenable_cmd.buffer);
 271 }
 272
 273 tpm_result_t tlcl1_set_deactivated(uint8_t flag)
 274 {
 275         struct s_tpm_physicalsetdeactivated_cmd cmd;
 276         VBDEBUG("TPM: SetDeactivated(%d)\n", flag);
 277         memcpy(&cmd, &tpm_physicalsetdeactivated_cmd, sizeof(cmd));
 278         *(cmd.buffer + cmd.deactivated) = flag;
 279         return send(cmd.buffer);
 280 }
 281
 282 tpm_result_t tlcl1_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags)
 283 {
 284         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 285         uint32_t size;
 286         tpm_result_t rc =
 287                 tlcl1_send_receive(tpm_getflags_cmd.buffer, response, sizeof(response));
 288         if (rc != TPM_SUCCESS)
 289                 return rc;
 290         from_tpm_uint32(response + kTpmResponseHeaderLength, &size);
 291         if (size != sizeof(TPM_PERMANENT_FLAGS))
 292                 return TPM_IOERROR;
 293         memcpy(pflags, response + kTpmResponseHeaderLength + sizeof(size),
 294                sizeof(TPM_PERMANENT_FLAGS));
 295         return rc;
 296 }
 297
 298 tpm_result_t tlcl1_get_flags(uint8_t *disable, uint8_t *deactivated, uint8_t *nvlocked)
 299 {
 300         TPM_PERMANENT_FLAGS pflags;
 301         tpm_result_t rc = tlcl1_get_permanent_flags(&pflags);
 302         if (rc == TPM_SUCCESS) {
 303                 if (disable)
 304                         *disable = pflags.disable;
 305                 if (deactivated)
 306                         *deactivated = pflags.deactivated;
 307                 if (nvlocked)
 308                         *nvlocked = pflags.nvLocked;
 309                 VBDEBUG("TPM: flags disable=%d, deactivated=%d, nvlocked=%d\n",
 310                         pflags.disable, pflags.deactivated, pflags.nvLocked);
 311         }
 312         return rc;
 313 }
 314
 315 tpm_result_t tlcl1_set_global_lock(void)
 316 {
 317         VBDEBUG("TPM: Set global lock\n");
 318         return tlcl1_write(TPM_NV_INDEX0, NULL, 0);
 319 }
 320
 321 tpm_result_t tlcl1_extend(int pcr_num, const uint8_t *digest_data,
 322                           enum vb2_hash_algorithm digest_algo)
 323 {
 324         struct s_tpm_extend_cmd cmd;
 325         uint8_t response[kTpmResponseHeaderLength + kPcrDigestLength];
 326
 327         if (digest_algo != VB2_HASH_SHA1)
 328                 return TPM_CB_INVALID_ARG;
 329
 330         memcpy(&cmd, &tpm_extend_cmd, sizeof(cmd));
 331         to_tpm_uint32(cmd.buffer + tpm_extend_cmd.pcrNum, pcr_num);
 332         memcpy(cmd.buffer + cmd.inDigest, digest_data, kPcrDigestLength);
 333
 334         return tlcl1_send_receive(cmd.buffer, response, sizeof(response));
 335 }
 336
 337 tpm_result_t tlcl1_get_permissions(uint32_t index, uint32_t *permissions)
 338 {
 339         struct s_tpm_getpermissions_cmd cmd;
 340         uint8_t response[TPM_LARGE_ENOUGH_COMMAND_SIZE];
 341         uint8_t *nvdata;
 342         tpm_result_t rc;
 343         uint32_t size;
 344
 345         memcpy(&cmd, &tpm_getpermissions_cmd, sizeof(cmd));
 346         to_tpm_uint32(cmd.buffer + tpm_getpermissions_cmd.index, index);
 347         rc = tlcl1_send_receive(cmd.buffer, response, sizeof(response));
 348         if (rc != TPM_SUCCESS)
 349                 return rc;
 350
 351         nvdata = response + kTpmResponseHeaderLength + sizeof(size);
 352         from_tpm_uint32(nvdata + kNvDataPublicPermissionsOffset, permissions);
 353         return rc;
 354 }