TPM: Verify PCR0 matches the bootmode if it is already initialized
Refuse to boot in case of a mismatch
Google-Bug-Id: 24814315
Change-Id: I6bd5abba7583eae95968fba4a63dd56f85497727
diff --git a/arch/arm/boards/optimus/tpm.c b/arch/arm/boards/optimus/tpm.c
index 1e5081f..e61eba1 100644
--- a/arch/arm/boards/optimus/tpm.c
+++ b/arch/arm/boards/optimus/tpm.c
@@ -35,44 +35,82 @@
#define PCR_DIGEST_LENGTH 20
+struct pcr_value_pair {
+ uint8_t digest[PCR_DIGEST_LENGTH];
+ uint8_t extended[PCR_DIGEST_LENGTH];
+};
+
struct bootmode_pcr_values {
- uint8_t normal_boot[PCR_DIGEST_LENGTH];
- uint8_t recovery_mode[PCR_DIGEST_LENGTH];
+ struct pcr_value_pair normal_boot;
+ struct pcr_value_pair recovery_mode;
};
static struct bootmode_pcr_values pcr_values_secure_boot = {
#ifdef CONFIG_DEVELOPER_BAREBOX
/* secure boot, normal boot, dev firmware [0, 0, 2] */
- .normal_boot = {0x1e, 0xf6, 0x24, 0x48, 0x2d, 0x62, 0x0e, 0x43, 0xe6, 0xd3,
- 0x4d, 0xa1, 0xaf, 0xe4, 0x62, 0x67, 0xfc, 0x69, 0x5d, 0x9b},
+ .normal_boot = {
+ .digest = {0x1e, 0xf6, 0x24, 0x48, 0x2d, 0x62, 0x0e, 0x43, 0xe6, 0xd3,
+ 0x4d, 0xa1, 0xaf, 0xe4, 0x62, 0x67, 0xfc, 0x69, 0x5d, 0x9b},
+ .extended = {0xee, 0x56, 0xc3, 0x2d, 0x5f, 0x7b, 0xfa, 0x56, 0xba, 0x92,
+ 0x6f, 0x66, 0x27, 0x0e, 0xc2, 0xe9, 0xd0, 0x1c, 0x64, 0xb3},
+ },
+
/* secure boot, recovery mode, dev firmware [0, 1, 2] */
- .recovery_mode = {0x0c, 0x7a, 0x62, 0x3f, 0xd2, 0xbb, 0xc0, 0x5b, 0x06, 0x42,
- 0x3b, 0xe3, 0x59, 0xe4, 0x02, 0x1d, 0x36, 0xe7, 0x21, 0xad},
+ .recovery_mode = {
+ .digest = {0x0c, 0x7a, 0x62, 0x3f, 0xd2, 0xbb, 0xc0, 0x5b, 0x06, 0x42,
+ 0x3b, 0xe3, 0x59, 0xe4, 0x02, 0x1d, 0x36, 0xe7, 0x21, 0xad},
+ .extended = {0x08, 0x20, 0xc4, 0xb6, 0x7b, 0x33, 0xb2, 0x81, 0x25, 0x6b,
+ 0x03, 0x53, 0xdc, 0xc9, 0xfa, 0x43, 0x66, 0xe4, 0x27, 0xaf},
+ },
#else
/* secure boot, normal boot, prod firmware [0, 0, 1] */
- .normal_boot = {0x25, 0x47, 0xcc, 0x73, 0x6e, 0x95, 0x1f, 0xa4, 0x91, 0x98,
- 0x53, 0xc4, 0x3a, 0xe8, 0x90, 0x86, 0x1a, 0x3b, 0x32, 0x64},
+ .normal_boot = {
+ .digest = {0x25, 0x47, 0xcc, 0x73, 0x6e, 0x95, 0x1f, 0xa4, 0x91, 0x98,
+ 0x53, 0xc4, 0x3a, 0xe8, 0x90, 0x86, 0x1a, 0x3b, 0x32, 0x64},
+ .extended = {0x06, 0x4a, 0xec, 0x9b, 0xbd, 0x94, 0xde, 0xa1, 0x23, 0x1a,
+ 0xe7, 0x57, 0x67, 0x64, 0x7f, 0x09, 0x8c, 0x39, 0x8e, 0x79},
+ },
/* secure boot, recovery mode, prod firmware [0, 1, 1] */
- .recovery_mode = {0xee, 0xe4, 0x47, 0xed, 0xc7, 0x9f, 0xea, 0x1c, 0xa7, 0xc7,
- 0xd3, 0x4e, 0x46, 0x32, 0x61, 0xcd, 0xa4, 0xba, 0x33, 0x9e},
+ .recovery_mode = {
+ .digest = {0xee, 0xe4, 0x47, 0xed, 0xc7, 0x9f, 0xea, 0x1c, 0xa7, 0xc7,
+ 0xd3, 0x4e, 0x46, 0x32, 0x61, 0xcd, 0xa4, 0xba, 0x33, 0x9e},
+ .extended = {0x17, 0x18, 0xb0, 0x87, 0xa1, 0x6a, 0x4e, 0x80, 0xe7, 0x50,
+ 0x74, 0xc8, 0x11, 0x09, 0xde, 0x23, 0x1a, 0x04, 0xc0, 0x0b},
+ },
#endif
};
static struct bootmode_pcr_values pcr_values_nonsecure_boot = {
#ifdef CONFIG_DEVELOPER_BAREBOX
/* non-secure boot, normal boot, dev firmware [1, 0, 2] */
- .normal_boot = {0xfa, 0x01, 0x0d, 0x26, 0x64, 0xcc, 0x5b, 0x3b, 0x82, 0xee,
- 0x48, 0x8f, 0xe2, 0xb9, 0xf5, 0x0f, 0x49, 0x32, 0xeb, 0x8f},
+ .normal_boot = {
+ .digest = {0xfa, 0x01, 0x0d, 0x26, 0x64, 0xcc, 0x5b, 0x3b, 0x82, 0xee,
+ 0x48, 0x8f, 0xe2, 0xb9, 0xf5, 0x0f, 0x49, 0x32, 0xeb, 0x8f},
+ .extended = {0x29, 0x56, 0x57, 0x4c, 0x9d, 0x6a, 0x95, 0xd3, 0x15, 0x8a,
+ 0x81, 0x45, 0x71, 0x6a, 0x25, 0x7c, 0x3f, 0x6d, 0x62, 0xc1},
+ },
/* non-secure boot, recovery mode, dev firmware [1, 1, 2] */
- .recovery_mode = {0x12, 0xa3, 0x40, 0xd7, 0x89, 0x7f, 0xe7, 0x13, 0xfc, 0x8f,
- 0x02, 0xac, 0x53, 0x65, 0xb8, 0x6e, 0xbf, 0x35, 0x31, 0x78},
+ .recovery_mode = {
+ .digest = {0x12, 0xa3, 0x40, 0xd7, 0x89, 0x7f, 0xe7, 0x13, 0xfc, 0x8f,
+ 0x02, 0xac, 0x53, 0x65, 0xb8, 0x6e, 0xbf, 0x35, 0x31, 0x78},
+ .extended = {0x36, 0x56, 0x6d, 0xe7, 0x9c, 0x23, 0x94, 0x2f, 0x1b, 0x79,
+ 0xcf, 0xd7, 0xde, 0x56, 0xe6, 0x9b, 0xe4, 0xfe, 0xcd, 0x72},
+ },
#else
/* non-secure boot, normal boot, dev firmware [1, 0, 2] */
- .normal_boot = {0xfa, 0x01, 0x0d, 0x26, 0x64, 0xcc, 0x5b, 0x3b, 0x82, 0xee,
- 0x48, 0x8f, 0xe2, 0xb9, 0xf5, 0x0f, 0x49, 0x32, 0xeb, 0x8f},
+ .normal_boot = {
+ .digest = {0xfa, 0x01, 0x0d, 0x26, 0x64, 0xcc, 0x5b, 0x3b, 0x82, 0xee,
+ 0x48, 0x8f, 0xe2, 0xb9, 0xf5, 0x0f, 0x49, 0x32, 0xeb, 0x8f},
+ .extended = {0x29, 0x56, 0x57, 0x4c, 0x9d, 0x6a, 0x95, 0xd3, 0x15, 0x8a,
+ 0x81, 0x45, 0x71, 0x6a, 0x25, 0x7c, 0x3f, 0x6d, 0x62, 0xc1},
+ },
/* non-secure boot, recovery mode, dev firmware [1, 1, 2] */
- .recovery_mode = {0x12, 0xa3, 0x40, 0xd7, 0x89, 0x7f, 0xe7, 0x13, 0xfc, 0x8f,
- 0x02, 0xac, 0x53, 0x65, 0xb8, 0x6e, 0xbf, 0x35, 0x31, 0x78},
+ .recovery_mode = {
+ .digest = {0x12, 0xa3, 0x40, 0xd7, 0x89, 0x7f, 0xe7, 0x13, 0xfc, 0x8f,
+ 0x02, 0xac, 0x53, 0x65, 0xb8, 0x6e, 0xbf, 0x35, 0x31, 0x78},
+ .extended = {0x36, 0x56, 0x6d, 0xe7, 0x9c, 0x23, 0x94, 0x2f, 0x1b, 0x79,
+ 0xcf, 0xd7, 0xde, 0x56, 0xe6, 0x9b, 0xe4, 0xfe, 0xcd, 0x72},
+ },
#endif
};
@@ -87,6 +125,13 @@
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
+static void pcr_value_to_string(const uint8_t *value, char *str) {
+ int i;
+ for (i = 0; i < PCR_DIGEST_LENGTH; i++) {
+ sprintf(&str[i * 2], "%02x", value[i]);
+ }
+}
+
uint32_t tpm_init(void) {
uint32_t result;
uint8_t disable;
@@ -111,6 +156,8 @@
RETURN_ON_FAILURE(tlcl_continue_self_test());
if (!is_recovery_mode()) {
+ struct pcr_value_pair *bootmode_pcr_values;
+
RETURN_ON_FAILURE(tlcl_get_flags(&disable, &deactivated, NULL));
if (disable || deactivated) {
printk(KERN_DEBUG "TPM: disabled (%d) or deactivated (%d). "
@@ -126,18 +173,27 @@
return TPM_E_MUST_REBOOT;
}
+ if (get_secure_boot_mode() == SECURE) {
+ bootmode_pcr_values = &pcr_values_secure_boot.normal_boot;
+ } else {
+ bootmode_pcr_values = &pcr_values_nonsecure_boot.normal_boot;
+ }
+
RETURN_ON_FAILURE(tlcl_read_pcr(0, pcr_value));
if (!memcmp(pcr_value, PCR_uninitialized, PCR_DIGEST_LENGTH)) {
/* PCR0 not initialized, extend it with the boot mode */
- const uint8_t *digest;
-
- if (get_secure_boot_mode() == SECURE) {
- digest = pcr_values_secure_boot.normal_boot;
- } else {
- digest = pcr_values_nonsecure_boot.normal_boot;
+ RETURN_ON_FAILURE(tlcl_extend(0, bootmode_pcr_values->digest, NULL));
+ } else {
+ /* PCR0 is initialized from previous boot, verify the value matches */
+ if (memcmp(pcr_value, bootmode_pcr_values->extended, PCR_DIGEST_LENGTH)) {
+ char str[PCR_DIGEST_LENGTH * 2 + 1];
+ printk("TPM: PCR0 mismatch\n");
+ pcr_value_to_string(bootmode_pcr_values->extended, str);
+ printk(" expected: %s\n", str);
+ pcr_value_to_string(pcr_value, str);
+ printk(" is: %s\n", str);
+ return TPM_E_MUST_REBOOT;
}
-
- RETURN_ON_FAILURE(tlcl_extend(0, digest, NULL));
}
} else {
const uint8_t *digest;
@@ -150,9 +206,9 @@
RETURN_ON_FAILURE(tlcl_set_deactivated(0));
if (get_secure_boot_mode() == SECURE) {
- digest = pcr_values_secure_boot.recovery_mode;
+ digest = pcr_values_secure_boot.recovery_mode.digest;
} else {
- digest = pcr_values_nonsecure_boot.recovery_mode;
+ digest = pcr_values_nonsecure_boot.recovery_mode.digest;
}
RETURN_ON_FAILURE(tlcl_extend(0, digest, NULL));
