u-boot/board/gdsys/a38x/hre.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2013
* Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc
*/
#include <common.h>
#include <malloc.h>
#include <fs.h>
#include <i2c.h>
#include <mmc.h>
#include <tpm-v1.h>
#include <u-boot/sha1.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <pca9698.h>
#include "hre.h"
/* other constants */
enum {
ESDHC_BOOT_IMAGE_SIG_OFS = 0x40,
ESDHC_BOOT_IMAGE_SIZE_OFS = 0x48,
ESDHC_BOOT_IMAGE_ADDR_OFS = 0x50,
ESDHC_BOOT_IMAGE_TARGET_OFS = 0x58,
ESDHC_BOOT_IMAGE_ENTRY_OFS = 0x60,
};
enum {
I2C_SOC_0 = 0,
I2C_SOC_1 = 1,
};
enum access_mode {
HREG_NONE = 0,
HREG_RD = 1,
HREG_WR = 2,
HREG_RDWR = 3,
};
/* register constants */
enum {
FIX_HREG_DEVICE_ID_HASH = 0,
FIX_HREG_UNUSED1 = 1,
FIX_HREG_UNUSED2 = 2,
FIX_HREG_VENDOR = 3,
COUNT_FIX_HREGS
};
static struct h_reg pcr_hregs[24];
static struct h_reg fix_hregs[COUNT_FIX_HREGS];
static struct h_reg var_hregs[8];
/* hre opcodes */
enum {
/* opcodes w/o data */
HRE_NOP = 0x00,
HRE_SYNC = HRE_NOP,
HRE_CHECK0 = 0x01,
/* opcodes w/o data, w/ sync dst */
/* opcodes w/ data */
HRE_LOAD = 0x81,
/* opcodes w/data, w/sync dst */
HRE_XOR = 0xC1,
HRE_AND = 0xC2,
HRE_OR = 0xC3,
HRE_EXTEND = 0xC4,
HRE_LOADKEY = 0xC5,
};
/* hre errors */
enum {
HRE_E_OK = 0,
HRE_E_TPM_FAILURE,
HRE_E_INVALID_HREG,
};
static uint64_t device_id;
static uint64_t device_cl;
static uint64_t device_type;
static uint32_t platform_key_handle;
static uint32_t hre_tpm_err;
static int hre_err = HRE_E_OK;
#define IS_PCR_HREG(spec) ((spec) & 0x20)
#define IS_FIX_HREG(spec) (((spec) & 0x38) == 0x08)
#define IS_VAR_HREG(spec) (((spec) & 0x38) == 0x10)
#define HREG_IDX(spec) ((spec) & (IS_PCR_HREG(spec) ? 0x1f : 0x7))
static const uint8_t vendor[] = "Guntermann & Drunck";
/**
* @brief get the size of a given (TPM) NV area
* @param index NV index of the area to get size for
* @param size pointer to the size
* @return 0 on success, != 0 on error
*/
static int get_tpm_nv_size(uint32_t index, uint32_t *size)
{
uint32_t err;
uint8_t info[72];
uint8_t *ptr;
uint16_t v16;
err = tpm_get_capability(TPM_CAP_NV_INDEX, index,
info, sizeof(info));
if (err) {
printf("tpm_get_capability(CAP_NV_INDEX, %08x) failed: %u\n",
index, err);
return 1;
}
/* skip tag and nvIndex */
ptr = info + 6;
/* skip 2 pcr info fields */
v16 = get_unaligned_be16(ptr);
ptr += 2 + v16 + 1 + 20;
v16 = get_unaligned_be16(ptr);
ptr += 2 + v16 + 1 + 20;
/* skip permission and flags */
ptr += 6 + 3;
*size = get_unaligned_be32(ptr);
return 0;
}
/**
* @brief search for a key by usage auth and pub key hash.
* @param auth usage auth of the key to search for
* @param pubkey_digest (SHA1) hash of the pub key structure of the key
* @param[out] handle the handle of the key iff found
* @return 0 if key was found in TPM; != 0 if not.
*/
static int find_key(const uint8_t auth[20], const uint8_t pubkey_digest[20],
uint32_t *handle)
{
uint16_t key_count;
uint32_t key_handles[10];
uint8_t buf[288];
uint8_t *ptr;
uint32_t err;
uint8_t digest[20];
size_t buf_len;
unsigned int i;
/* fetch list of already loaded keys in the TPM */
err = tpm_get_capability(TPM_CAP_HANDLE, TPM_RT_KEY, buf, sizeof(buf));
if (err)
return -1;
key_count = get_unaligned_be16(buf);
ptr = buf + 2;
for (i = 0; i < key_count; ++i, ptr += 4)
key_handles[i] = get_unaligned_be32(ptr);
/* now search a(/ the) key which we can access with the given auth */
for (i = 0; i < key_count; ++i) {
buf_len = sizeof(buf);
err = tpm_get_pub_key_oiap(key_handles[i], auth, buf, &buf_len);
if (err && err != TPM_AUTHFAIL)
return -1;
if (err)
continue;
sha1_csum(buf, buf_len, digest);
if (!memcmp(digest, pubkey_digest, 20)) {
*handle = key_handles[i];
return 0;
}
}
return 1;
}
/**
* @brief read CCDM common data from TPM NV
* @return 0 if CCDM common data was found and read, !=0 if something failed.
*/
static int read_common_data(void)
{
uint32_t size = 0;
uint32_t err;
uint8_t buf[256];
sha1_context ctx;
if (get_tpm_nv_size(NV_COMMON_DATA_INDEX, &size) ||
size < NV_COMMON_DATA_MIN_SIZE)
return 1;
err = tpm_nv_read_value(NV_COMMON_DATA_INDEX,
buf, min(sizeof(buf), size));
if (err) {
printf("tpm_nv_read_value() failed: %u\n", err);
return 1;
}
device_id = get_unaligned_be64(buf);
device_cl = get_unaligned_be64(buf + 8);
device_type = get_unaligned_be64(buf + 16);
sha1_starts(&ctx);
sha1_update(&ctx, buf, 24);
sha1_finish(&ctx, fix_hregs[FIX_HREG_DEVICE_ID_HASH].digest);
fix_hregs[FIX_HREG_DEVICE_ID_HASH].valid = true;
platform_key_handle = get_unaligned_be32(buf + 24);
return 0;
}
/**
* @brief get pointer to hash register by specification
* @param spec specification of a hash register
* @return pointer to hash register or NULL if @a spec does not qualify a
* valid hash register; NULL else.
*/
static struct h_reg *get_hreg(uint8_t spec)
{
uint8_t idx;
idx = HREG_IDX(spec);
if (IS_FIX_HREG(spec)) {
if (idx < ARRAY_SIZE(fix_hregs))
return fix_hregs + idx;
hre_err = HRE_E_INVALID_HREG;
} else if (IS_PCR_HREG(spec)) {
if (idx < ARRAY_SIZE(pcr_hregs))
return pcr_hregs + idx;
hre_err = HRE_E_INVALID_HREG;
} else if (IS_VAR_HREG(spec)) {
if (idx < ARRAY_SIZE(var_hregs))
return var_hregs + idx;
hre_err = HRE_E_INVALID_HREG;
}
return NULL;
}
/**
* @brief get pointer of a hash register by specification and usage.
* @param spec specification of a hash register
* @param mode access mode (read or write or read/write)
* @return pointer to hash register if found and valid; NULL else.
*
* This func uses @a get_reg() to determine the hash register for a given spec.
* If a register is found it is validated according to the desired access mode.
* The value of automatic registers (PCR register and fixed registers) is
* loaded or computed on read access.
*/
static struct h_reg *access_hreg(uint8_t spec, enum access_mode mode)
{
struct h_reg *result;
result = get_hreg(spec);
if (!result)
return NULL;
if (mode & HREG_WR) {
if (IS_FIX_HREG(spec)) {
hre_err = HRE_E_INVALID_HREG;
return NULL;
}
}
if (mode & HREG_RD) {
if (!result->valid) {
if (IS_PCR_HREG(spec)) {
hre_tpm_err = tpm_pcr_read(HREG_IDX(spec),
result->digest, 20);
result->valid = (hre_tpm_err == TPM_SUCCESS);
} else if (IS_FIX_HREG(spec)) {
switch (HREG_IDX(spec)) {
case FIX_HREG_DEVICE_ID_HASH:
read_common_data();
break;
case FIX_HREG_VENDOR:
memcpy(result->digest, vendor, 20);
result->valid = true;
break;
}
} else {
result->valid = true;
}
}
if (!result->valid) {
hre_err = HRE_E_INVALID_HREG;
return NULL;
}
}
return result;
}
static void *compute_and(void *_dst, const void *_src, size_t n)
{
uint8_t *dst = _dst;
const uint8_t *src = _src;
size_t i;
for (i = n; i-- > 0; )
*dst++ &= *src++;
return _dst;
}
static void *compute_or(void *_dst, const void *_src, size_t n)
{
uint8_t *dst = _dst;
const uint8_t *src = _src;
size_t i;
for (i = n; i-- > 0; )
*dst++ |= *src++;
return _dst;
}
static void *compute_xor(void *_dst, const void *_src, size_t n)
{
uint8_t *dst = _dst;
const uint8_t *src = _src;
size_t i;
for (i = n; i-- > 0; )
*dst++ ^= *src++;
return _dst;
}
static void *compute_extend(void *_dst, const void *_src, size_t n)
{
uint8_t digest[20];
sha1_context ctx;
sha1_starts(&ctx);
sha1_update(&ctx, _dst, n);
sha1_update(&ctx, _src, n);
sha1_finish(&ctx, digest);
memcpy(_dst, digest, min(n, sizeof(digest)));
return _dst;
}
static int hre_op_loadkey(struct h_reg *src_reg, struct h_reg *dst_reg,
const void *key, size_t key_size)
{
uint32_t parent_handle;
uint32_t key_handle;
if (!src_reg || !dst_reg || !src_reg->valid || !dst_reg->valid)
return -1;
if (find_key(src_reg->digest, dst_reg->digest, &parent_handle))
return -1;
hre_tpm_err = tpm_load_key2_oiap(parent_handle, key, key_size,
src_reg->digest, &key_handle);
if (hre_tpm_err) {
hre_err = HRE_E_TPM_FAILURE;
return -1;
}
return 0;
}
/**
* @brief executes the next opcode on the hash register engine.
* @param[in,out] ip pointer to the opcode (instruction pointer)
* @param[in,out] code_size (remaining) size of the code
* @return new instruction pointer on success, NULL on error.
*/
static const uint8_t *hre_execute_op(const uint8_t **ip, size_t *code_size)
{
bool dst_modified = false;
uint32_t ins;
uint8_t opcode;
uint8_t src_spec;
uint8_t dst_spec;
uint16_t data_size;
struct h_reg *src_reg, *dst_reg;
uint8_t buf[20];
const uint8_t *src_buf, *data;
uint8_t *ptr;
int i;
void * (*bin_func)(void *, const void *, size_t);
if (*code_size < 4)
return NULL;
ins = get_unaligned_be32(*ip);
opcode = **ip;
data = *ip + 4;
src_spec = (ins >> 18) & 0x3f;
dst_spec = (ins >> 12) & 0x3f;
data_size = (ins & 0x7ff);
debug("HRE: ins=%08x (op=%02x, s=%02x, d=%02x, L=%d)\n", ins,
opcode, src_spec, dst_spec, data_size);
if ((opcode & 0x80) && (data_size + 4) > *code_size)
return NULL;
src_reg = access_hreg(src_spec, HREG_RD);
if (hre_err || hre_tpm_err)
return NULL;
dst_reg = access_hreg(dst_spec, (opcode & 0x40) ? HREG_RDWR : HREG_WR);
if (hre_err || hre_tpm_err)
return NULL;
switch (opcode) {
case HRE_NOP:
goto end;
case HRE_CHECK0:
if (src_reg) {
for (i = 0; i < 20; ++i) {
if (src_reg->digest[i])
return NULL;
}
}
break;
case HRE_LOAD:
bin_func = memcpy;
goto do_bin_func;
case HRE_XOR:
bin_func = compute_xor;
goto do_bin_func;
case HRE_AND:
bin_func = compute_and;
goto do_bin_func;
case HRE_OR:
bin_func = compute_or;
goto do_bin_func;
case HRE_EXTEND:
bin_func = compute_extend;
do_bin_func:
if (!dst_reg)
return NULL;
if (src_reg) {
src_buf = src_reg->digest;
} else {
if (!data_size) {
memset(buf, 0, 20);
src_buf = buf;
} else if (data_size == 1) {
memset(buf, *data, 20);
src_buf = buf;
} else if (data_size >= 20) {
src_buf = data;
} else {
src_buf = buf;
for (ptr = (uint8_t *)src_buf, i = 20; i > 0;
i -= data_size, ptr += data_size)
memcpy(ptr, data,
min_t(size_t, i, data_size));
}
}
bin_func(dst_reg->digest, src_buf, 20);
dst_reg->valid = true;
dst_modified = true;
break;
case HRE_LOADKEY:
if (hre_op_loadkey(src_reg, dst_reg, data, data_size))
return NULL;
break;
default:
return NULL;
}
if (dst_reg && dst_modified && IS_PCR_HREG(dst_spec)) {
hre_tpm_err = tpm_extend(HREG_IDX(dst_spec), dst_reg->digest,
dst_reg->digest);
if (hre_tpm_err) {
hre_err = HRE_E_TPM_FAILURE;
return NULL;
}
}
end:
*ip += 4;
*code_size -= 4;
if (opcode & 0x80) {
*ip += data_size;
*code_size -= data_size;
}
return *ip;
}
/**
* @brief runs a program on the hash register engine.
* @param code pointer to the (HRE) code.
* @param code_size size of the code (in bytes).
* @return 0 on success, != 0 on failure.
*/
int hre_run_program(const uint8_t *code, size_t code_size)
{
size_t code_left;
const uint8_t *ip = code;
code_left = code_size;
hre_tpm_err = 0;
hre_err = HRE_E_OK;
while (code_left > 0)
if (!hre_execute_op(&ip, &code_left))
return -1;
return hre_err;
}
int hre_verify_program(struct key_program *prg)
{
uint32_t crc;
crc = crc32(0, prg->code, prg->code_size);
if (crc != prg->code_crc) {
printf("HRC crc mismatch: %08x != %08x\n",
crc, prg->code_crc);
return 1;
}
return 0;
}