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Diffstat (limited to 'board/gdsys/a38x/hre.c')
-rw-r--r-- | board/gdsys/a38x/hre.c | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/board/gdsys/a38x/hre.c b/board/gdsys/a38x/hre.c new file mode 100644 index 0000000000..1689d44db6 --- /dev/null +++ b/board/gdsys/a38x/hre.c @@ -0,0 +1,516 @@ +/* + * (C) Copyright 2013 + * Reinhard Pfau, Guntermann & Drunck GmbH, reinhard.pfau@gdsys.cc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <malloc.h> +#include <fs.h> +#include <i2c.h> +#include <mmc.h> +#include <tpm.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; +} |