[PATCH v2 0/8] The great TCG deduplication saga

Hi all
Apologies on resending so fast. We are close to the release and some patches are needed. This is v2 of [0]
Not much changed, since v1. The major change is that I managed to split the code and headers file moving around as Heinrich asked for easier review
Changes since v1: - Added a comment on why we return EFI_INVALID_PARAMETER on failures while EFI_DEVICE_ERROR would make more sense - Fixed some typos - split patch 4 to 2 patches - collected r-b tags
The testing was ok again, and comparing the eventlog between versions had no changes -- aprt from PCR0 which is expected
Ilias Apalodimas (8): tpm: fix the return code, if the eventlog buffer is full efi_loader: fix the return values on efi_tcg efi_loader: remove unused TCG algo definitions tpm: Move TCG headers into a separate file tpm: Move TCG functions into a separate file efi_loader: remove unneeded header files tpm: Untangle tpm2_get_pcr_info() tpm: allow the user to select the compiled algorithms
boot/Kconfig | 4 + boot/bootm.c | 1 + include/efi_tcg2.h | 9 +- include/tpm-v2.h | 388 +++---------------- include/tpm_tcg2.h | 348 +++++++++++++++++ lib/Kconfig | 6 +- lib/Makefile | 2 + lib/efi_loader/efi_tcg2.c | 129 ++++--- lib/tpm-v2.c | 767 +++----------------------------------- lib/tpm_tcg2.c | 731 ++++++++++++++++++++++++++++++++++++ 10 files changed, 1262 insertions(+), 1123 deletions(-) create mode 100644 include/tpm_tcg2.h create mode 100644 lib/tpm_tcg2.c
-- 2.45.2

We currently return 'No space left on device' if the eventlong buffer we allocated is not enough. On a similar check later on that function during the call to tcg2_log_init() we return 'No buffer space available'. So switch both error codes to -ENOBUFS since we are always checking a buffer and not a device.
Fixes: commit 97707f12fdab ("tpm: Support boot measurements") Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- lib/tpm-v2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index a67daed2f3c1..91526af33acb 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -554,7 +554,7 @@ int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, if (elog->log_size) { if (log.found) { if (elog->log_size < log.log_position) - return -ENOSPC; + return -ENOBUFS;
/* * Copy the discovered log into the user buffer

Hi Ilias,
On Sun, 23 Jun 2024 at 05:48, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
We currently return 'No space left on device' if the eventlong buffer we allocated is not enough. On a similar check later on that function during the call to tcg2_log_init() we return 'No buffer space available'. So switch both error codes to -ENOBUFS since we are always checking a buffer and not a device.
Fixes: commit 97707f12fdab ("tpm: Support boot measurements") Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/tpm-v2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
For better or worse, we mostly use -ENOSPC for this sort of thing. But this will at least make the TPM error stand out.
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index a67daed2f3c1..91526af33acb 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -554,7 +554,7 @@ int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, if (elog->log_size) { if (log.found) { if (elog->log_size < log.log_position)
return -ENOSPC;
return -ENOBUFS; /* * Copy the discovered log into the user buffer
-- 2.45.2
Regards, Simon

Hi Simon,
On Mon, 24 Jun 2024 at 00:52, Simon Glass sjg@chromium.org wrote:
Hi Ilias,
On Sun, 23 Jun 2024 at 05:48, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
We currently return 'No space left on device' if the eventlong buffer we allocated is not enough. On a similar check later on that function during the call to tcg2_log_init() we return 'No buffer space available'. So switch both error codes to -ENOBUFS since we are always checking a buffer and not a device.
Fixes: commit 97707f12fdab ("tpm: Support boot measurements") Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
lib/tpm-v2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
Thanks
For better or worse, we mostly use -ENOSPC for this sort of thing. But this will at least make the TPM error stand out.
The TCG spec is an EFI one. Since we moved that code to u-boots core we had to convert the return values from efi to int etc. We need mapping to be as precise as possible. The reason I switched this to ENOBUFS is because it seemed more appropriate. I just wanted that function to be coherent on the return code, I can switch both errors to ENOSPC just as easily.
/Ilias
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index a67daed2f3c1..91526af33acb 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -554,7 +554,7 @@ int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, if (elog->log_size) { if (log.found) { if (elog->log_size < log.log_position)
return -ENOSPC;
return -ENOBUFS; /* * Copy the discovered log into the user buffer
-- 2.45.2
Regards, Simon

A while back we moved the core functions of the EFI TCG protocol to the TPM APIs in order for them to be used with bootm, booti etc. Some prototypes changed from returning efi_status_t to int, which is more appropriate for the non-EFI APIs. However, some of the EFI callsites never changed and we ended up assigning the int value to efi_status_t.
This is unlikely to cause any problems, apart from returning invalid values on failures and violating the EFI spec. Let's fix them by looking at the new return code and map it to the proper EFI return code on failures.
Fixes: commit 97707f12fdab ("tpm: Support boot measurements") Fixes: commit d6b55a420cfc ("efi_loader: startup the tpm device when installing the protocol") Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- lib/efi_loader/efi_tcg2.c | 126 +++++++++++++++++++++----------------- 1 file changed, 69 insertions(+), 57 deletions(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index d56bd5657c8a..b4915cab6be7 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -257,8 +257,8 @@ efi_tcg2_get_capability(struct efi_tcg2_protocol *this, capability->protocol_version.major = 1; capability->protocol_version.minor = 1;
- efi_ret = tcg2_platform_get_tpm2(&dev); - if (efi_ret != EFI_SUCCESS) { + ret = tcg2_platform_get_tpm2(&dev); + if (ret) { capability->supported_event_logs = 0; capability->hash_algorithm_bitmap = 0; capability->tpm_present_flag = false; @@ -353,8 +353,7 @@ efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this, goto out; }
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) { + if (tcg2_platform_get_tpm2(&dev)) { event_log_location = NULL; event_log_last_entry = NULL; *event_log_truncated = false; @@ -389,7 +388,7 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size, void *new_efi = NULL; u8 hash[TPM2_SHA512_DIGEST_SIZE]; struct udevice *dev; - efi_status_t ret; + efi_status_t ret = EFI_SUCCESS; u32 active; int i;
@@ -404,12 +403,13 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size, goto out; }
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) { + ret = EFI_DEVICE_ERROR; goto out; + }
- ret = tcg2_get_active_pcr_banks(dev, &active); - if (ret != EFI_SUCCESS) { + if (tcg2_get_active_pcr_banks(dev, &active)) { + ret = EFI_DEVICE_ERROR; goto out; }
@@ -473,12 +473,12 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size, IMAGE_DOS_HEADER *dos; IMAGE_NT_HEADERS32 *nt; struct efi_handler *handler; + int rc;
if (!is_tcg2_protocol_installed()) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) return EFI_SECURITY_VIOLATION;
switch (handle->image_type) { @@ -502,9 +502,9 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size, if (ret != EFI_SUCCESS) return ret;
- ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); - if (ret != EFI_SUCCESS) - return ret; + rc = tcg2_pcr_extend(dev, pcr_index, &digest_list); + if (rc) + return EFI_DEVICE_ERROR;
ret = efi_search_protocol(&handle->header, &efi_guid_loaded_image_device_path, &handler); @@ -574,9 +574,10 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, struct efi_tcg2_event *efi_tcg_event) { struct udevice *dev; - efi_status_t ret; + efi_status_t ret = EFI_SUCCESS; u32 event_type, pcr_index, event_size; struct tpml_digest_values digest_list; + int rc = 0;
EFI_ENTRY("%p, %llu, %llu, %llu, %p", this, flags, data_to_hash, data_to_hash_len, efi_tcg_event); @@ -586,9 +587,10 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, goto out; }
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) { + ret = EFI_DEVICE_ERROR; goto out; + }
if (efi_tcg_event->size < efi_tcg_event->header.header_size + sizeof(u32)) { @@ -621,8 +623,10 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, ret = tcg2_hash_pe_image((void *)(uintptr_t)data_to_hash, data_to_hash_len, &digest_list); } else { - ret = tcg2_create_digest(dev, (u8 *)(uintptr_t)data_to_hash, - data_to_hash_len, &digest_list); + rc = tcg2_create_digest(dev, (u8 *)(uintptr_t)data_to_hash, + data_to_hash_len, &digest_list); + if (rc) + ret = EFI_DEVICE_ERROR; }
if (ret != EFI_SUCCESS) @@ -631,9 +635,11 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags, pcr_index = efi_tcg_event->header.pcr_index; event_type = efi_tcg_event->header.event_type;
- ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); - if (ret != EFI_SUCCESS) + rc = tcg2_pcr_extend(dev, pcr_index, &digest_list); + if (rc) { + ret = EFI_DEVICE_ERROR; goto out; + }
if (flags & EFI_TCG2_EXTEND_ONLY) { if (event_log.truncated) @@ -672,7 +678,7 @@ efi_tcg2_submit_command(struct efi_tcg2_protocol *this, u8 *output_param_block) { struct udevice *dev; - efi_status_t ret; + efi_status_t ret = EFI_SUCCESS; u32 rc; size_t resp_buf_size = output_param_block_size;
@@ -684,9 +690,10 @@ efi_tcg2_submit_command(struct efi_tcg2_protocol *this, goto out; }
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) { + ret = EFI_DEVICE_ERROR; goto out; + }
rc = tpm2_submit_command(dev, input_param_block, output_param_block, &resp_buf_size); @@ -714,19 +721,25 @@ efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this, u32 *active_pcr_banks) { struct udevice *dev; - efi_status_t ret; + efi_status_t ret = EFI_INVALID_PARAMETER;
EFI_ENTRY("%p, %p", this, active_pcr_banks);
- if (!this || !active_pcr_banks) { - ret = EFI_INVALID_PARAMETER; + if (!this || !active_pcr_banks) goto out; - } - ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + + if (tcg2_platform_get_tpm2(&dev)) + goto out; + + /* + * EFI_INVALID_PARAMETER does not convey the problem type. + * but that's what currently the spec specifies. + * EFI_DEVICE_ERROR would be better + */ + if (tcg2_get_active_pcr_banks(dev, active_pcr_banks)) goto out;
- ret = tcg2_get_active_pcr_banks(dev, active_pcr_banks); + ret = EFI_SUCCESS;
out: return EFI_EXIT(ret); @@ -852,14 +865,15 @@ static efi_status_t measure_event(struct udevice *dev, u32 pcr_index, u32 event_type, u32 size, u8 event[]) { struct tpml_digest_values digest_list; - efi_status_t ret; + efi_status_t ret = EFI_DEVICE_ERROR; + int rc;
- ret = tcg2_create_digest(dev, event, size, &digest_list); - if (ret != EFI_SUCCESS) + rc = tcg2_create_digest(dev, event, size, &digest_list); + if (rc) goto out;
- ret = tcg2_pcr_extend(dev, pcr_index, &digest_list); - if (ret != EFI_SUCCESS) + rc = tcg2_pcr_extend(dev, pcr_index, &digest_list); + if (rc) goto out;
ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list, @@ -901,10 +915,10 @@ static efi_status_t efi_init_event_log(void) struct tcg2_event_log elog; struct udevice *dev; efi_status_t ret; + int rc;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) - return ret; + if (tcg2_platform_get_tpm2(&dev)) + return EFI_DEVICE_ERROR;
ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE, (void **)&event_log.buffer); @@ -933,9 +947,11 @@ static efi_status_t efi_init_event_log(void) */ elog.log = event_log.buffer; elog.log_size = TPM2_EVENT_LOG_SIZE; - ret = tcg2_log_prepare_buffer(dev, &elog, false); - if (ret != EFI_SUCCESS) + rc = tcg2_log_prepare_buffer(dev, &elog, false); + if (rc) { + ret = (rc == -ENOBUFS) ? EFI_BUFFER_TOO_SMALL : EFI_DEVICE_ERROR; goto free_pool; + }
event_log.pos = elog.log_position;
@@ -1306,8 +1322,7 @@ efi_status_t efi_tcg2_measure_dtb(void *dtb) if (!is_tcg2_protocol_installed()) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) return EFI_SECURITY_VIOLATION;
rsvmap_size = size_of_rsvmap(dtb); @@ -1356,8 +1371,7 @@ efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *ha if (tcg2_efi_app_invoked) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) return EFI_SECURITY_VIOLATION;
ret = tcg2_measure_boot_variable(dev); @@ -1406,9 +1420,8 @@ efi_status_t efi_tcg2_measure_efi_app_exit(void) if (!is_tcg2_protocol_installed()) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) - return ret; + if (tcg2_platform_get_tpm2(&dev)) + return EFI_SECURITY_VIOLATION;
ret = measure_event(dev, 4, EV_EFI_ACTION, strlen(EFI_RETURNING_FROM_EFI_APPLICATION), @@ -1437,9 +1450,10 @@ efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context) goto out; }
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) { + ret = EFI_SECURITY_VIOLATION; goto out; + }
ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION), @@ -1469,9 +1483,8 @@ efi_status_t efi_tcg2_notify_exit_boot_services_failed(void) if (!is_tcg2_protocol_installed()) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) - goto out; + if (tcg2_platform_get_tpm2(&dev)) + return EFI_SECURITY_VIOLATION;
ret = measure_event(dev, 5, EV_EFI_ACTION, strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION), @@ -1551,8 +1564,7 @@ efi_status_t efi_tcg2_do_initial_measurement(void) if (!is_tcg2_protocol_installed()) return EFI_SUCCESS;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) + if (tcg2_platform_get_tpm2(&dev)) return EFI_SECURITY_VIOLATION;
ret = tcg2_measure_secure_boot_variable(dev); @@ -1577,8 +1589,7 @@ efi_status_t efi_tcg2_register(void) struct efi_event *event; u32 err;
- ret = tcg2_platform_get_tpm2(&dev); - if (ret != EFI_SUCCESS) { + if (tcg2_platform_get_tpm2(&dev)) { log_warning("Missing TPMv2 device for EFI_TCG_PROTOCOL\n"); return EFI_SUCCESS; } @@ -1586,6 +1597,7 @@ efi_status_t efi_tcg2_register(void) /* initialize the TPM as early as possible. */ err = tpm_auto_start(dev); if (err) { + ret = EFI_DEVICE_ERROR; log_err("TPM startup failed\n"); goto fail; }

commit 97707f12fdab ("tpm: Support boot measurements") moved some of the EFI TCG code to the TPM subsystem. Those definitions are now in tpm-v2.h. Let's remove the stale entries
Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- include/efi_tcg2.h | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h index a75b5a35b6e7..54490969b2d1 100644 --- a/include/efi_tcg2.h +++ b/include/efi_tcg2.h @@ -25,14 +25,6 @@ #define PE_COFF_IMAGE 0x0000000000000010
#define EFI_TCG2_MAX_PCR_INDEX 23 - -/* Algorithm Registry */ -#define EFI_TCG2_BOOT_HASH_ALG_SHA1 0x00000001 -#define EFI_TCG2_BOOT_HASH_ALG_SHA256 0x00000002 -#define EFI_TCG2_BOOT_HASH_ALG_SHA384 0x00000004 -#define EFI_TCG2_BOOT_HASH_ALG_SHA512 0x00000008 -#define EFI_TCG2_BOOT_HASH_ALG_SM3_256 0x00000010 - #define EFI_TCG2_FINAL_EVENTS_TABLE_VERSION 1
#define TPM2_EVENT_LOG_SIZE CONFIG_EFI_TCG2_PROTOCOL_EVENTLOG_SIZE

commit 97707f12fdab ("tpm: Support boot measurements") moved out code from the EFI subsystem into the TPM one to support measurements when booting with !EFI.
Those were moved directly into the TPM subsystem and in the tpm-v2.c library. In hindsight, it would have been better to move it in new files since the TCG2 is governed by its own spec, it's overeall cleaner and also easier to enable certain parts of the TPM functionality.
So let's start moving the headers in a new file containing the TCG specific bits.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- boot/bootm.c | 1 + include/efi_tcg2.h | 1 + include/tpm-v2.h | 131 ---------------------------------------- include/tpm_tcg2.h | 146 +++++++++++++++++++++++++++++++++++++++++++++ lib/tpm-v2.c | 1 + 5 files changed, 149 insertions(+), 131 deletions(-) create mode 100644 include/tpm_tcg2.h
diff --git a/boot/bootm.c b/boot/bootm.c index 9879e1bba4eb..395b42cccd88 100644 --- a/boot/bootm.c +++ b/boot/bootm.c @@ -25,6 +25,7 @@ #include <asm/io.h> #include <linux/sizes.h> #include <tpm-v2.h> +#include <tpm_tcg2.h> #if defined(CONFIG_CMD_USB) #include <usb.h> #endif diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h index 54490969b2d1..8dfb1bc9527b 100644 --- a/include/efi_tcg2.h +++ b/include/efi_tcg2.h @@ -18,6 +18,7 @@
#include <efi_api.h> #include <tpm-v2.h> +#include <tpm_tcg2.h>
/* TPMV2 only */ #define TCG2_EVENT_LOG_FORMAT_TCG_2 0x00000002 diff --git a/include/tpm-v2.h b/include/tpm-v2.h index c9d5cb6d3e5a..38d79207e321 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -55,59 +55,6 @@ struct udevice; #define TPM2_PT_MAX_COMMAND_SIZE (u32)(TPM2_PT_FIXED + 30) #define TPM2_PT_MAX_RESPONSE_SIZE (u32)(TPM2_PT_FIXED + 31)
-/* - * event types, cf. - * "TCG Server Management Domain Firmware Profile Specification", - * rev 1.00, 2020-05-01 - */ -#define EV_POST_CODE ((u32)0x00000001) -#define EV_NO_ACTION ((u32)0x00000003) -#define EV_SEPARATOR ((u32)0x00000004) -#define EV_ACTION ((u32)0x00000005) -#define EV_TAG ((u32)0x00000006) -#define EV_S_CRTM_CONTENTS ((u32)0x00000007) -#define EV_S_CRTM_VERSION ((u32)0x00000008) -#define EV_CPU_MICROCODE ((u32)0x00000009) -#define EV_PLATFORM_CONFIG_FLAGS ((u32)0x0000000A) -#define EV_TABLE_OF_DEVICES ((u32)0x0000000B) -#define EV_COMPACT_HASH ((u32)0x0000000C) - -/* - * event types, cf. - * "TCG PC Client Platform Firmware Profile Specification", Family "2.0" - * Level 00 Version 1.05 Revision 23, May 7, 2021 - */ -#define EV_EFI_EVENT_BASE ((u32)0x80000000) -#define EV_EFI_VARIABLE_DRIVER_CONFIG ((u32)0x80000001) -#define EV_EFI_VARIABLE_BOOT ((u32)0x80000002) -#define EV_EFI_BOOT_SERVICES_APPLICATION ((u32)0x80000003) -#define EV_EFI_BOOT_SERVICES_DRIVER ((u32)0x80000004) -#define EV_EFI_RUNTIME_SERVICES_DRIVER ((u32)0x80000005) -#define EV_EFI_GPT_EVENT ((u32)0x80000006) -#define EV_EFI_ACTION ((u32)0x80000007) -#define EV_EFI_PLATFORM_FIRMWARE_BLOB ((u32)0x80000008) -#define EV_EFI_HANDOFF_TABLES ((u32)0x80000009) -#define EV_EFI_PLATFORM_FIRMWARE_BLOB2 ((u32)0x8000000A) -#define EV_EFI_HANDOFF_TABLES2 ((u32)0x8000000B) -#define EV_EFI_VARIABLE_BOOT2 ((u32)0x8000000C) -#define EV_EFI_HCRTM_EVENT ((u32)0x80000010) -#define EV_EFI_VARIABLE_AUTHORITY ((u32)0x800000E0) -#define EV_EFI_SPDM_FIRMWARE_BLOB ((u32)0x800000E1) -#define EV_EFI_SPDM_FIRMWARE_CONFIG ((u32)0x800000E2) - -#define EFI_CALLING_EFI_APPLICATION \ - "Calling EFI Application from Boot Option" -#define EFI_RETURNING_FROM_EFI_APPLICATION \ - "Returning from EFI Application from Boot Option" -#define EFI_EXIT_BOOT_SERVICES_INVOCATION \ - "Exit Boot Services Invocation" -#define EFI_EXIT_BOOT_SERVICES_FAILED \ - "Exit Boot Services Returned with Failure" -#define EFI_EXIT_BOOT_SERVICES_SUCCEEDED \ - "Exit Boot Services Returned with Success" -#define EFI_DTB_EVENT_STRING \ - "DTB DATA" - /* TPMS_TAGGED_PROPERTY Structure */ struct tpms_tagged_property { u32 property; @@ -149,23 +96,6 @@ struct tpms_capability_data { union tpmu_capabilities data; } __packed;
-/** - * SHA1 Event Log Entry Format - * - * @pcr_index: PCRIndex event extended to - * @event_type: Type of event (see EFI specs) - * @digest: Value extended into PCR index - * @event_size: Size of event - * @event: Event data - */ -struct tcg_pcr_event { - u32 pcr_index; - u32 event_type; - u8 digest[TPM2_SHA1_DIGEST_SIZE]; - u32 event_size; - u8 event[]; -} __packed; - /** * Definition of TPMU_HA Union */ @@ -199,67 +129,6 @@ struct tpml_digest_values { struct tpmt_ha digests[TPM2_NUM_PCR_BANKS]; } __packed;
-/** - * Crypto Agile Log Entry Format - * - * @pcr_index: PCRIndex event extended to - * @event_type: Type of event - * @digests: List of digestsextended to PCR index - * @event_size: Size of the event data - * @event: Event data - */ -struct tcg_pcr_event2 { - u32 pcr_index; - u32 event_type; - struct tpml_digest_values digests; - u32 event_size; - u8 event[]; -} __packed; - -/** - * struct TCG_EfiSpecIdEventAlgorithmSize - hashing algorithm information - * - * @algorithm_id: algorithm defined in enum tpm2_algorithms - * @digest_size: size of the algorithm - */ -struct tcg_efi_spec_id_event_algorithm_size { - u16 algorithm_id; - u16 digest_size; -} __packed; - -#define TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03 "Spec ID Event03" -#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2 2 -#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 0 -#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2 2 - -/** - * struct TCG_EfiSpecIDEventStruct - content of the event log header - * - * @signature: signature, set to Spec ID Event03 - * @platform_class: class defined in TCG ACPI Specification - * Client Common Header. - * @spec_version_minor: minor version - * @spec_version_major: major version - * @spec_version_errata: major version - * @uintn_size: size of the efi_uintn_t fields used in various - * data structures used in this specification. - * 0x01 indicates u32 and 0x02 indicates u64 - * @number_of_algorithms: hashing algorithms used in this event log - * @digest_sizes: array of number_of_algorithms pairs - * 1st member defines the algorithm id - * 2nd member defines the algorithm size - */ -struct tcg_efi_spec_id_event { - u8 signature[16]; - u32 platform_class; - u8 spec_version_minor; - u8 spec_version_major; - u8 spec_errata; - u8 uintn_size; - u32 number_of_algorithms; - struct tcg_efi_spec_id_event_algorithm_size digest_sizes[]; -} __packed; - /** * TPM2 Structure Tags for command/response buffers. * diff --git a/include/tpm_tcg2.h b/include/tpm_tcg2.h new file mode 100644 index 000000000000..581ff6f24a4c --- /dev/null +++ b/include/tpm_tcg2.h @@ -0,0 +1,146 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Defines APIs and structures that adhere to + * https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmw... + * https://trustedcomputinggroup.org/resource/tcg-efi-protocol-specification/ + * + * Copyright (c) 2020 Linaro Limited + */ + +#ifndef __TPM_TCG_V2_H +#define __TPM_TCG_V2_H + +#include <tpm-v2.h> + +/* + * event types, cf. + * "TCG Server Management Domain Firmware Profile Specification", + * rev 1.00, 2020-05-01 + */ +#define EV_POST_CODE ((u32)0x00000001) +#define EV_NO_ACTION ((u32)0x00000003) +#define EV_SEPARATOR ((u32)0x00000004) +#define EV_ACTION ((u32)0x00000005) +#define EV_TAG ((u32)0x00000006) +#define EV_S_CRTM_CONTENTS ((u32)0x00000007) +#define EV_S_CRTM_VERSION ((u32)0x00000008) +#define EV_CPU_MICROCODE ((u32)0x00000009) +#define EV_PLATFORM_CONFIG_FLAGS ((u32)0x0000000A) +#define EV_TABLE_OF_DEVICES ((u32)0x0000000B) +#define EV_COMPACT_HASH ((u32)0x0000000C) + +/* + * event types, cf. + * "TCG PC Client Platform Firmware Profile Specification", Family "2.0" + * Level 00 Version 1.05 Revision 23, May 7, 2021 + */ +#define EV_EFI_EVENT_BASE ((u32)0x80000000) +#define EV_EFI_VARIABLE_DRIVER_CONFIG ((u32)0x80000001) +#define EV_EFI_VARIABLE_BOOT ((u32)0x80000002) +#define EV_EFI_BOOT_SERVICES_APPLICATION ((u32)0x80000003) +#define EV_EFI_BOOT_SERVICES_DRIVER ((u32)0x80000004) +#define EV_EFI_RUNTIME_SERVICES_DRIVER ((u32)0x80000005) +#define EV_EFI_GPT_EVENT ((u32)0x80000006) +#define EV_EFI_ACTION ((u32)0x80000007) +#define EV_EFI_PLATFORM_FIRMWARE_BLOB ((u32)0x80000008) +#define EV_EFI_HANDOFF_TABLES ((u32)0x80000009) +#define EV_EFI_PLATFORM_FIRMWARE_BLOB2 ((u32)0x8000000A) +#define EV_EFI_HANDOFF_TABLES2 ((u32)0x8000000B) +#define EV_EFI_VARIABLE_BOOT2 ((u32)0x8000000C) +#define EV_EFI_HCRTM_EVENT ((u32)0x80000010) +#define EV_EFI_VARIABLE_AUTHORITY ((u32)0x800000E0) +#define EV_EFI_SPDM_FIRMWARE_BLOB ((u32)0x800000E1) +#define EV_EFI_SPDM_FIRMWARE_CONFIG ((u32)0x800000E2) + +#define EFI_CALLING_EFI_APPLICATION \ + "Calling EFI Application from Boot Option" +#define EFI_RETURNING_FROM_EFI_APPLICATION \ + "Returning from EFI Application from Boot Option" +#define EFI_EXIT_BOOT_SERVICES_INVOCATION \ + "Exit Boot Services Invocation" +#define EFI_EXIT_BOOT_SERVICES_FAILED \ + "Exit Boot Services Returned with Failure" +#define EFI_EXIT_BOOT_SERVICES_SUCCEEDED \ + "Exit Boot Services Returned with Success" +#define EFI_DTB_EVENT_STRING \ + "DTB DATA" + +/** + * struct TCG_EfiSpecIdEventAlgorithmSize - hashing algorithm information + * + * @algorithm_id: algorithm defined in enum tpm2_algorithms + * @digest_size: size of the algorithm + */ +struct tcg_efi_spec_id_event_algorithm_size { + u16 algorithm_id; + u16 digest_size; +} __packed; + +/** + * SHA1 Event Log Entry Format + * + * @pcr_index: PCRIndex event extended to + * @event_type: Type of event (see EFI specs) + * @digest: Value extended into PCR index + * @event_size: Size of event + * @event: Event data + */ +struct tcg_pcr_event { + u32 pcr_index; + u32 event_type; + u8 digest[TPM2_SHA1_DIGEST_SIZE]; + u32 event_size; + u8 event[]; +} __packed; + +/** + * Crypto Agile Log Entry Format + * + * @pcr_index: PCRIndex event extended to + * @event_type: Type of event + * @digests: List of digestsextended to PCR index + * @event_size: Size of the event data + * @event: Event data + */ +struct tcg_pcr_event2 { + u32 pcr_index; + u32 event_type; + struct tpml_digest_values digests; + u32 event_size; + u8 event[]; +} __packed; + +/** + * struct TCG_EfiSpecIDEventStruct - content of the event log header + * + * @signature: signature, set to Spec ID Event03 + * @platform_class: class defined in TCG ACPI Specification + * Client Common Header. + * @spec_version_minor: minor version + * @spec_version_major: major version + * @spec_version_errata: major version + * @uintn_size: size of the efi_uintn_t fields used in various + * data structures used in this specification. + * 0x01 indicates u32 and 0x02 indicates u64 + * @number_of_algorithms: hashing algorithms used in this event log + * @digest_sizes: array of number_of_algorithms pairs + * 1st member defines the algorithm id + * 2nd member defines the algorithm size + */ +struct tcg_efi_spec_id_event { + u8 signature[16]; + u32 platform_class; + u8 spec_version_minor; + u8 spec_version_major; + u8 spec_errata; + u8 uintn_size; + u32 number_of_algorithms; + struct tcg_efi_spec_id_event_algorithm_size digest_sizes[]; +} __packed; + +#define TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03 "Spec ID Event03" +#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2 2 +#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 0 +#define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2 2 + +#endif /* __TPM_TCG_V2_H */ diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 91526af33acb..c3832bb7f767 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -10,6 +10,7 @@ #include <tpm_api.h> #include <tpm-common.h> #include <tpm-v2.h> +#include <tpm_tcg2.h> #include <u-boot/sha1.h> #include <u-boot/sha256.h> #include <u-boot/sha512.h>

The previous patch is moving the TPM TCG headers in their own file for a cleaner API. Move the functions in their own file as well.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- include/tpm-v2.h | 190 ------------- include/tpm_tcg2.h | 189 ++++++++++++ lib/Makefile | 2 + lib/tpm-v2.c | 675 +------------------------------------------ lib/tpm_tcg2.c | 695 +++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 887 insertions(+), 864 deletions(-) create mode 100644 lib/tpm_tcg2.c
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index 38d79207e321..fc7c58204e58 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -399,188 +399,6 @@ enum { HR_NV_INDEX = TPM_HT_NV_INDEX << HR_SHIFT, };
-/** - * struct tcg2_event_log - Container for managing the platform event log - * - * @log: Address of the log - * @log_position: Current entry position - * @log_size: Log space available - * @found: Boolean indicating if an existing log was discovered - */ -struct tcg2_event_log { - u8 *log; - u32 log_position; - u32 log_size; - bool found; -}; - -/** - * Create a list of digests of the supported PCR banks for a given input data - * - * @dev TPM device - * @input Data - * @length Length of the data to calculate the digest - * @digest_list List of digests to fill in - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length, - struct tpml_digest_values *digest_list); - -/** - * Get the event size of the specified digests - * - * @digest_list List of digests for the event - * - * Return: Size in bytes of the event - */ -u32 tcg2_event_get_size(struct tpml_digest_values *digest_list); - -/** - * tcg2_get_active_pcr_banks - * - * @dev TPM device - * @active_pcr_banks Bitmask of PCR algorithms supported - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks); - -/** - * tcg2_log_append - Append an event to an event log - * - * @pcr_index Index of the PCR - * @event_type Type of event - * @digest_list List of digests to add - * @size Size of event - * @event Event data - * @log Log buffer to append the event to - */ -void tcg2_log_append(u32 pcr_index, u32 event_type, - struct tpml_digest_values *digest_list, u32 size, - const u8 *event, u8 *log); - -/** - * Extend the PCR with specified digests - * - * @dev TPM device - * @pcr_index Index of the PCR - * @digest_list List of digests to extend - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index, - struct tpml_digest_values *digest_list); - -/** - * Read the PCR into a list of digests - * - * @dev TPM device - * @pcr_index Index of the PCR - * @digest_list List of digests to extend - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_pcr_read(struct udevice *dev, u32 pcr_index, - struct tpml_digest_values *digest_list); - -/** - * Measure data into the TPM PCRs and the platform event log. - * - * @dev TPM device - * @log Platform event log - * @pcr_index Index of the PCR - * @size Size of the data or 0 for event only - * @data Pointer to the data or NULL for event only - * @event_type Event log type - * @event_size Size of the event - * @event Pointer to the event - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog, - u32 pcr_index, u32 size, const u8 *data, u32 event_type, - u32 event_size, const u8 *event); - -#define tcg2_measure_event(dev, elog, pcr_index, event_type, size, event) \ - tcg2_measure_data(dev, elog, pcr_index, 0, NULL, event_type, size, \ - event) - -/** - * Prepare the event log buffer. This function tries to discover an existing - * event log in memory from a previous bootloader stage. If such a log exists - * and the PCRs are not extended, the log is "replayed" to extend the PCRs. - * If no log is discovered, create the log header. - * - * @dev TPM device - * @elog Platform event log. The log pointer and log_size - * members must be initialized to either 0 or to a valid - * memory region, in which case any existing log - * discovered will be copied to the specified memory - * region. - * @ignore_existing_log Boolean to indicate whether or not to ignore an - * existing platform log in memory - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, - bool ignore_existing_log); - -/** - * Begin measurements. - * - * @dev TPM device - * @elog Platform event log. The log pointer and log_size - * members must be initialized to either 0 or to a valid - * memory region, in which case any existing log - * discovered will be copied to the specified memory - * region. - * @ignore_existing_log Boolean to indicate whether or not to ignore an - * existing platform log in memory - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog, - bool ignore_existing_log); - -/** - * Stop measurements and record separator events. - * - * @dev TPM device - * @elog Platform event log - * @error Boolean to indicate whether an error ocurred or not - */ -void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog, - bool error); - -/** - * Get the platform event log address and size. - * - * @dev TPM device - * @addr Address of the log - * @size Size of the log - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size); - -/** - * Get the first TPM2 device found. - * - * @dev TPM device - * - * Return: zero on success, negative errno otherwise - */ -int tcg2_platform_get_tpm2(struct udevice **dev); - -/** - * Platform-specific function for handling TPM startup errors - * - * @dev TPM device - * @rc The TPM response code - */ -void tcg2_platform_startup_error(struct udevice *dev, int rc); - /** * Issue a TPM2_Startup command. * @@ -897,12 +715,4 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); */ const char *tpm2_algorithm_name(enum tpm2_algorithms);
-/** - * tpm2_algorithm_to_mask() - Get a TCG hash mask for algorithm - * - * @hash_alg: TCG defined algorithm - * Return: TCG hashing algorithm bitmaps (or 0 if algo not supported) - */ -u32 tpm2_algorithm_to_mask(enum tpm2_algorithms); - #endif /* __TPM_V2_H */ diff --git a/include/tpm_tcg2.h b/include/tpm_tcg2.h index 581ff6f24a4c..4e4ea1e8067d 100644 --- a/include/tpm_tcg2.h +++ b/include/tpm_tcg2.h @@ -142,5 +142,194 @@ struct tcg_efi_spec_id_event { #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2 2 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 0 #define TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2 2 +/** + * struct tcg2_event_log - Container for managing the platform event log + * + * @log: Address of the log + * @log_position: Current entry position + * @log_size: Log space available + * @found: Boolean indicating if an existing log was discovered + */ +struct tcg2_event_log { + u8 *log; + u32 log_position; + u32 log_size; + bool found; +}; + +/** + * Create a list of digests of the supported PCR banks for a given input data + * + * @dev TPM device + * @input Data + * @length Length of the data to calculate the digest + * @digest_list List of digests to fill in + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length, + struct tpml_digest_values *digest_list); + +/** + * Get the event size of the specified digests + * + * @digest_list List of digests for the event + * + * Return: Size in bytes of the event + */ +u32 tcg2_event_get_size(struct tpml_digest_values *digest_list); + +/** + * tcg2_get_active_pcr_banks + * + * @dev TPM device + * @active_pcr_banks Bitmask of PCR algorithms supported + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks); + +/** + * tcg2_log_append - Append an event to an event log + * + * @pcr_index Index of the PCR + * @event_type Type of event + * @digest_list List of digests to add + * @size Size of event + * @event Event data + * @log Log buffer to append the event to + */ +void tcg2_log_append(u32 pcr_index, u32 event_type, + struct tpml_digest_values *digest_list, u32 size, + const u8 *event, u8 *log); + +/** + * Extend the PCR with specified digests + * + * @dev TPM device + * @pcr_index Index of the PCR + * @digest_list List of digests to extend + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index, + struct tpml_digest_values *digest_list); + +/** + * Read the PCR into a list of digests + * + * @dev TPM device + * @pcr_index Index of the PCR + * @digest_list List of digests to extend + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_pcr_read(struct udevice *dev, u32 pcr_index, + struct tpml_digest_values *digest_list); + +/** + * Measure data into the TPM PCRs and the platform event log. + * + * @dev TPM device + * @log Platform event log + * @pcr_index Index of the PCR + * @size Size of the data or 0 for event only + * @data Pointer to the data or NULL for event only + * @event_type Event log type + * @event_size Size of the event + * @event Pointer to the event + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog, + u32 pcr_index, u32 size, const u8 *data, u32 event_type, + u32 event_size, const u8 *event); + +#define tcg2_measure_event(dev, elog, pcr_index, event_type, size, event) \ + tcg2_measure_data(dev, elog, pcr_index, 0, NULL, event_type, size, \ + event) + +/** + * Prepare the event log buffer. This function tries to discover an existing + * event log in memory from a previous bootloader stage. If such a log exists + * and the PCRs are not extended, the log is "replayed" to extend the PCRs. + * If no log is discovered, create the log header. + * + * @dev TPM device + * @elog Platform event log. The log pointer and log_size + * members must be initialized to either 0 or to a valid + * memory region, in which case any existing log + * discovered will be copied to the specified memory + * region. + * @ignore_existing_log Boolean to indicate whether or not to ignore an + * existing platform log in memory + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, + bool ignore_existing_log); + +/** + * Begin measurements. + * + * @dev TPM device + * @elog Platform event log. The log pointer and log_size + * members must be initialized to either 0 or to a valid + * memory region, in which case any existing log + * discovered will be copied to the specified memory + * region. + * @ignore_existing_log Boolean to indicate whether or not to ignore an + * existing platform log in memory + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog, + bool ignore_existing_log); + +/** + * Stop measurements and record separator events. + * + * @dev TPM device + * @elog Platform event log + * @error Boolean to indicate whether an error ocurred or not + */ +void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog, + bool error); + +/** + * Get the platform event log address and size. + * + * @dev TPM device + * @addr Address of the log + * @size Size of the log + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size); + +/** + * Get the first TPM2 device found. + * + * @dev TPM device + * + * Return: zero on success, negative errno otherwise + */ +int tcg2_platform_get_tpm2(struct udevice **dev); + +/** + * Platform-specific function for handling TPM startup errors + * + * @dev TPM device + * @rc The TPM response code + */ +void tcg2_platform_startup_error(struct udevice *dev, int rc); + +/** + * tcg2_algorithm_to_mask() - Get a TCG hash mask for algorithm + * + * @hash_alg: TCG defined algorithm + * Return: TCG hashing algorithm bitmaps (or 0 if algo not supported) + */ +u32 tcg2_algorithm_to_mask(enum tpm2_algorithms);
#endif /* __TPM_TCG_V2_H */ diff --git a/lib/Makefile b/lib/Makefile index 2a76acf100d0..e389ad014f89 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -61,6 +61,8 @@ ifeq ($(CONFIG_$(SPL_TPL_)TPM),y) obj-$(CONFIG_TPM) += tpm_api.o obj-$(CONFIG_TPM_V1) += tpm-v1.o obj-$(CONFIG_TPM_V2) += tpm-v2.o +obj-$(CONFIG_EFI_TCG2_PROTOCOL) += tpm_tcg2.o +obj-$(CONFIG_MEASURED_BOOT) += tpm_tcg2.o endif
obj-$(CONFIG_$(SPL_TPL_)CRC8) += crc8.o diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index c3832bb7f767..62ab804b4b38 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -23,668 +23,6 @@
#include "tpm-utils.h"
-int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks) -{ - u32 supported = 0; - u32 pcr_banks = 0; - u32 active = 0; - int rc; - - rc = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks); - if (rc) - return rc; - - *active_pcr_banks = active; - - return 0; -} - -u32 tcg2_event_get_size(struct tpml_digest_values *digest_list) -{ - u32 len; - size_t i; - - len = offsetof(struct tcg_pcr_event2, digests); - len += offsetof(struct tpml_digest_values, digests); - for (i = 0; i < digest_list->count; ++i) { - u16 l = tpm2_algorithm_to_len(digest_list->digests[i].hash_alg); - - if (!l) - continue; - - len += l + offsetof(struct tpmt_ha, digest); - } - len += sizeof(u32); - - return len; -} - -int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length, - struct tpml_digest_values *digest_list) -{ - u8 final[sizeof(union tpmu_ha)]; - sha256_context ctx_256; - sha512_context ctx_512; - sha1_context ctx; - u32 active; - size_t i; - u32 len; - int rc; - - rc = tcg2_get_active_pcr_banks(dev, &active); - if (rc) - return rc; - - digest_list->count = 0; - for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { - if (!(active & hash_algo_list[i].hash_mask)) - continue; - - switch (hash_algo_list[i].hash_alg) { - case TPM2_ALG_SHA1: - sha1_starts(&ctx); - sha1_update(&ctx, input, length); - sha1_finish(&ctx, final); - len = TPM2_SHA1_DIGEST_SIZE; - break; - case TPM2_ALG_SHA256: - sha256_starts(&ctx_256); - sha256_update(&ctx_256, input, length); - sha256_finish(&ctx_256, final); - len = TPM2_SHA256_DIGEST_SIZE; - break; - case TPM2_ALG_SHA384: - sha384_starts(&ctx_512); - sha384_update(&ctx_512, input, length); - sha384_finish(&ctx_512, final); - len = TPM2_SHA384_DIGEST_SIZE; - break; - case TPM2_ALG_SHA512: - sha512_starts(&ctx_512); - sha512_update(&ctx_512, input, length); - sha512_finish(&ctx_512, final); - len = TPM2_SHA512_DIGEST_SIZE; - break; - default: - printf("%s: unsupported algorithm %x\n", __func__, - hash_algo_list[i].hash_alg); - continue; - } - - digest_list->digests[digest_list->count].hash_alg = - hash_algo_list[i].hash_alg; - memcpy(&digest_list->digests[digest_list->count].digest, final, - len); - digest_list->count++; - } - - return 0; -} - -void tcg2_log_append(u32 pcr_index, u32 event_type, - struct tpml_digest_values *digest_list, u32 size, - const u8 *event, u8 *log) -{ - size_t len; - size_t pos; - u32 i; - - pos = offsetof(struct tcg_pcr_event2, pcr_index); - put_unaligned_le32(pcr_index, log); - pos = offsetof(struct tcg_pcr_event2, event_type); - put_unaligned_le32(event_type, log + pos); - pos = offsetof(struct tcg_pcr_event2, digests) + - offsetof(struct tpml_digest_values, count); - put_unaligned_le32(digest_list->count, log + pos); - - pos = offsetof(struct tcg_pcr_event2, digests) + - offsetof(struct tpml_digest_values, digests); - for (i = 0; i < digest_list->count; ++i) { - u16 hash_alg = digest_list->digests[i].hash_alg; - - len = tpm2_algorithm_to_len(hash_alg); - if (!len) - continue; - - pos += offsetof(struct tpmt_ha, hash_alg); - put_unaligned_le16(hash_alg, log + pos); - pos += offsetof(struct tpmt_ha, digest); - memcpy(log + pos, (u8 *)&digest_list->digests[i].digest, len); - pos += len; - } - - put_unaligned_le32(size, log + pos); - pos += sizeof(u32); - memcpy(log + pos, event, size); -} - -static int tcg2_log_append_check(struct tcg2_event_log *elog, u32 pcr_index, - u32 event_type, - struct tpml_digest_values *digest_list, - u32 size, const u8 *event) -{ - u32 event_size; - u8 *log; - - event_size = size + tcg2_event_get_size(digest_list); - if (elog->log_position + event_size > elog->log_size) { - printf("%s: log too large: %u + %u > %u\n", __func__, - elog->log_position, event_size, elog->log_size); - return -ENOBUFS; - } - - log = elog->log + elog->log_position; - elog->log_position += event_size; - - tcg2_log_append(pcr_index, event_type, digest_list, size, event, log); - - return 0; -} - -static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog) -{ - struct tcg_efi_spec_id_event *ev; - struct tcg_pcr_event *log; - u32 event_size; - u32 count = 0; - u32 log_size; - u32 active; - size_t i; - u16 len; - int rc; - - rc = tcg2_get_active_pcr_banks(dev, &active); - if (rc) - return rc; - - event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes); - for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { - if (!(active & hash_algo_list[i].hash_mask)) - continue; - - switch (hash_algo_list[i].hash_alg) { - case TPM2_ALG_SHA1: - case TPM2_ALG_SHA256: - case TPM2_ALG_SHA384: - case TPM2_ALG_SHA512: - count++; - break; - default: - continue; - } - } - - event_size += 1 + - (sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count); - log_size = offsetof(struct tcg_pcr_event, event) + event_size; - - if (log_size > elog->log_size) { - printf("%s: log too large: %u > %u\n", __func__, log_size, - elog->log_size); - return -ENOBUFS; - } - - log = (struct tcg_pcr_event *)elog->log; - put_unaligned_le32(0, &log->pcr_index); - put_unaligned_le32(EV_NO_ACTION, &log->event_type); - memset(&log->digest, 0, sizeof(log->digest)); - put_unaligned_le32(event_size, &log->event_size); - - ev = (struct tcg_efi_spec_id_event *)log->event; - strlcpy((char *)ev->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, - sizeof(ev->signature)); - put_unaligned_le32(0, &ev->platform_class); - ev->spec_version_minor = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2; - ev->spec_version_major = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2; - ev->spec_errata = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2; - ev->uintn_size = sizeof(size_t) / sizeof(u32); - put_unaligned_le32(count, &ev->number_of_algorithms); - - count = 0; - for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { - if (!(active & hash_algo_list[i].hash_mask)) - continue; - - len = hash_algo_list[i].hash_len; - if (!len) - continue; - - put_unaligned_le16(hash_algo_list[i].hash_alg, - &ev->digest_sizes[count].algorithm_id); - put_unaligned_le16(len, &ev->digest_sizes[count].digest_size); - count++; - } - - *((u8 *)ev + (event_size - 1)) = 0; - elog->log_position = log_size; - - return 0; -} - -static int tcg2_replay_eventlog(struct tcg2_event_log *elog, - struct udevice *dev, - struct tpml_digest_values *digest_list, - u32 log_position) -{ - const u32 offset = offsetof(struct tcg_pcr_event2, digests) + - offsetof(struct tpml_digest_values, digests); - u32 event_size; - u32 count; - u16 algo; - u32 pcr; - u32 pos; - u16 len; - u8 *log; - int rc; - u32 i; - - while (log_position + offset < elog->log_size) { - log = elog->log + log_position; - - pos = offsetof(struct tcg_pcr_event2, pcr_index); - pcr = get_unaligned_le32(log + pos); - pos = offsetof(struct tcg_pcr_event2, event_type); - if (!get_unaligned_le32(log + pos)) - return 0; - - pos = offsetof(struct tcg_pcr_event2, digests) + - offsetof(struct tpml_digest_values, count); - count = get_unaligned_le32(log + pos); - if (count > ARRAY_SIZE(hash_algo_list) || - (digest_list->count && digest_list->count != count)) - return 0; - - pos = offsetof(struct tcg_pcr_event2, digests) + - offsetof(struct tpml_digest_values, digests); - for (i = 0; i < count; ++i) { - pos += offsetof(struct tpmt_ha, hash_alg); - if (log_position + pos + sizeof(u16) >= elog->log_size) - return 0; - - algo = get_unaligned_le16(log + pos); - pos += offsetof(struct tpmt_ha, digest); - switch (algo) { - case TPM2_ALG_SHA1: - case TPM2_ALG_SHA256: - case TPM2_ALG_SHA384: - case TPM2_ALG_SHA512: - len = tpm2_algorithm_to_len(algo); - break; - default: - return 0; - } - - if (digest_list->count) { - if (algo != digest_list->digests[i].hash_alg || - log_position + pos + len >= elog->log_size) - return 0; - - memcpy(digest_list->digests[i].digest.sha512, - log + pos, len); - } - - pos += len; - } - - if (log_position + pos + sizeof(u32) >= elog->log_size) - return 0; - - event_size = get_unaligned_le32(log + pos); - pos += event_size + sizeof(u32); - if (log_position + pos > elog->log_size) - return 0; - - if (digest_list->count) { - rc = tcg2_pcr_extend(dev, pcr, digest_list); - if (rc) - return rc; - } - - log_position += pos; - } - - elog->log_position = log_position; - elog->found = true; - return 0; -} - -static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog) -{ - struct tpml_digest_values digest_list; - struct tcg_efi_spec_id_event *event; - struct tcg_pcr_event *log; - u32 log_active; - u32 calc_size; - u32 active; - u32 count; - u32 evsz; - u32 mask; - u16 algo; - u16 len; - int rc; - u32 i; - u16 j; - - if (elog->log_size <= offsetof(struct tcg_pcr_event, event)) - return 0; - - log = (struct tcg_pcr_event *)elog->log; - if (get_unaligned_le32(&log->pcr_index) != 0 || - get_unaligned_le32(&log->event_type) != EV_NO_ACTION) - return 0; - - for (i = 0; i < sizeof(log->digest); i++) { - if (log->digest[i]) - return 0; - } - - evsz = get_unaligned_le32(&log->event_size); - if (evsz < offsetof(struct tcg_efi_spec_id_event, digest_sizes) || - evsz + offsetof(struct tcg_pcr_event, event) > elog->log_size) - return 0; - - event = (struct tcg_efi_spec_id_event *)log->event; - if (memcmp(event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, - sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03))) - return 0; - - if (event->spec_version_minor != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 || - event->spec_version_major != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2) - return 0; - - count = get_unaligned_le32(&event->number_of_algorithms); - if (count > ARRAY_SIZE(hash_algo_list)) - return 0; - - calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) + - (sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count) + - 1; - if (evsz != calc_size) - return 0; - - rc = tcg2_get_active_pcr_banks(dev, &active); - if (rc) - return rc; - - digest_list.count = 0; - log_active = 0; - - for (i = 0; i < count; ++i) { - algo = get_unaligned_le16(&event->digest_sizes[i].algorithm_id); - mask = tpm2_algorithm_to_mask(algo); - - if (!(active & mask)) - return 0; - - switch (algo) { - case TPM2_ALG_SHA1: - case TPM2_ALG_SHA256: - case TPM2_ALG_SHA384: - case TPM2_ALG_SHA512: - len = get_unaligned_le16(&event->digest_sizes[i].digest_size); - if (tpm2_algorithm_to_len(algo) != len) - return 0; - digest_list.digests[digest_list.count++].hash_alg = algo; - break; - default: - return 0; - } - - log_active |= mask; - } - - /* Ensure the previous firmware extended all the PCRs. */ - if (log_active != active) - return 0; - - /* Read PCR0 to check if previous firmware extended the PCRs or not. */ - rc = tcg2_pcr_read(dev, 0, &digest_list); - if (rc) - return rc; - - for (i = 0; i < digest_list.count; ++i) { - len = tpm2_algorithm_to_len(digest_list.digests[i].hash_alg); - for (j = 0; j < len; ++j) { - if (digest_list.digests[i].digest.sha512[j]) - break; - } - - /* PCR is non-zero; it has been extended, so skip extending. */ - if (j != len) { - digest_list.count = 0; - break; - } - } - - return tcg2_replay_eventlog(elog, dev, &digest_list, - offsetof(struct tcg_pcr_event, event) + - evsz); -} - -int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index, - struct tpml_digest_values *digest_list) -{ - u32 rc; - u32 i; - - for (i = 0; i < digest_list->count; i++) { - u32 alg = digest_list->digests[i].hash_alg; - - rc = tpm2_pcr_extend(dev, pcr_index, alg, - (u8 *)&digest_list->digests[i].digest, - tpm2_algorithm_to_len(alg)); - if (rc) { - printf("%s: error pcr:%u alg:%08x\n", __func__, - pcr_index, alg); - return rc; - } - } - - return 0; -} - -int tcg2_pcr_read(struct udevice *dev, u32 pcr_index, - struct tpml_digest_values *digest_list) -{ - struct tpm_chip_priv *priv; - u32 rc; - u32 i; - - priv = dev_get_uclass_priv(dev); - if (!priv) - return -ENODEV; - - for (i = 0; i < digest_list->count; i++) { - u32 alg = digest_list->digests[i].hash_alg; - u8 *digest = (u8 *)&digest_list->digests[i].digest; - - rc = tpm2_pcr_read(dev, pcr_index, priv->pcr_select_min, alg, - digest, tpm2_algorithm_to_len(alg), NULL); - if (rc) { - printf("%s: error pcr:%u alg:%08x\n", __func__, - pcr_index, alg); - return rc; - } - } - - return 0; -} - -int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog, - u32 pcr_index, u32 size, const u8 *data, u32 event_type, - u32 event_size, const u8 *event) -{ - struct tpml_digest_values digest_list; - int rc; - - if (data) - rc = tcg2_create_digest(dev, data, size, &digest_list); - else - rc = tcg2_create_digest(dev, event, event_size, &digest_list); - if (rc) - return rc; - - rc = tcg2_pcr_extend(dev, pcr_index, &digest_list); - if (rc) - return rc; - - return tcg2_log_append_check(elog, pcr_index, event_type, &digest_list, - event_size, event); -} - -int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, - bool ignore_existing_log) -{ - struct tcg2_event_log log; - int rc; - - elog->log_position = 0; - elog->found = false; - - rc = tcg2_platform_get_log(dev, (void **)&log.log, &log.log_size); - if (!rc) { - log.log_position = 0; - log.found = false; - - if (!ignore_existing_log) { - rc = tcg2_log_parse(dev, &log); - if (rc) - return rc; - } - - if (elog->log_size) { - if (log.found) { - if (elog->log_size < log.log_position) - return -ENOBUFS; - - /* - * Copy the discovered log into the user buffer - * if there's enough space. - */ - memcpy(elog->log, log.log, log.log_position); - } - - unmap_physmem(log.log, MAP_NOCACHE); - } else { - elog->log = log.log; - elog->log_size = log.log_size; - } - - elog->log_position = log.log_position; - elog->found = log.found; - } - - /* - * Initialize the log buffer if no log was discovered and the buffer is - * valid. User's can pass in their own buffer as a fallback if no - * memory region is found. - */ - if (!elog->found && elog->log_size) - rc = tcg2_log_init(dev, elog); - - return rc; -} - -int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog, - bool ignore_existing_log) -{ - int rc; - - rc = tcg2_platform_get_tpm2(dev); - if (rc) - return rc; - - rc = tpm_auto_start(*dev); - if (rc) - return rc; - - rc = tcg2_log_prepare_buffer(*dev, elog, ignore_existing_log); - if (rc) { - tcg2_measurement_term(*dev, elog, true); - return rc; - } - - rc = tcg2_measure_event(*dev, elog, 0, EV_S_CRTM_VERSION, - strlen(version_string) + 1, - (u8 *)version_string); - if (rc) { - tcg2_measurement_term(*dev, elog, true); - return rc; - } - - return 0; -} - -void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog, - bool error) -{ - u32 event = error ? 0x1 : 0xffffffff; - int i; - - for (i = 0; i < 8; ++i) - tcg2_measure_event(dev, elog, i, EV_SEPARATOR, sizeof(event), - (const u8 *)&event); - - if (elog->log) - unmap_physmem(elog->log, MAP_NOCACHE); -} - -__weak int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size) -{ - const __be32 *addr_prop; - const __be32 *size_prop; - int asize; - int ssize; - - *addr = NULL; - *size = 0; - - addr_prop = dev_read_prop(dev, "tpm_event_log_addr", &asize); - if (!addr_prop) - addr_prop = dev_read_prop(dev, "linux,sml-base", &asize); - - size_prop = dev_read_prop(dev, "tpm_event_log_size", &ssize); - if (!size_prop) - size_prop = dev_read_prop(dev, "linux,sml-size", &ssize); - - if (addr_prop && size_prop) { - u64 a = of_read_number(addr_prop, asize / sizeof(__be32)); - u64 s = of_read_number(size_prop, ssize / sizeof(__be32)); - - *addr = map_physmem(a, s, MAP_NOCACHE); - *size = (u32)s; - } else { - struct ofnode_phandle_args args; - phys_addr_t a; - fdt_size_t s; - - if (dev_read_phandle_with_args(dev, "memory-region", NULL, 0, - 0, &args)) - return -ENODEV; - - a = ofnode_get_addr_size(args.node, "reg", &s); - if (a == FDT_ADDR_T_NONE) - return -ENOMEM; - - *addr = map_physmem(a, s, MAP_NOCACHE); - *size = (u32)s; - } - - return 0; -} - -__weak int tcg2_platform_get_tpm2(struct udevice **dev) -{ - for_each_tpm_device(*dev) { - if (tpm_get_version(*dev) == TPM_V2) - return 0; - } - - return -ENODEV; -} - -__weak void tcg2_platform_startup_error(struct udevice *dev, int rc) {} - u32 tpm2_startup(struct udevice *dev, enum tpm2_startup_types mode) { const u8 command_v2[12] = { @@ -1141,7 +479,7 @@ int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, }
for (i = 0; i < pcrs.count; i++) { - u32 hash_mask = tpm2_algorithm_to_mask(pcrs.selection[i].hash); + u32 hash_mask = tcg2_algorithm_to_mask(pcrs.selection[i].hash);
if (hash_mask) { *supported_pcr |= hash_mask; @@ -1567,14 +905,3 @@ const char *tpm2_algorithm_name(enum tpm2_algorithms algo) return ""; }
-u32 tpm2_algorithm_to_mask(enum tpm2_algorithms algo) -{ - size_t i; - - for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) { - if (hash_algo_list[i].hash_alg == algo) - return hash_algo_list[i].hash_mask; - } - - return 0; -} diff --git a/lib/tpm_tcg2.c b/lib/tpm_tcg2.c new file mode 100644 index 000000000000..91b9612fd3f6 --- /dev/null +++ b/lib/tpm_tcg2.c @@ -0,0 +1,695 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2023 Linaro Limited + */ + +#include <dm.h> +#include <dm/of_access.h> +#include <tpm_api.h> +#include <tpm-common.h> +#include <tpm-v2.h> +#include <tpm_tcg2.h> +#include <u-boot/sha1.h> +#include <u-boot/sha256.h> +#include <u-boot/sha512.h> +#include <version_string.h> +#include <asm/io.h> +#include <linux/bitops.h> +#include <linux/unaligned/be_byteshift.h> +#include <linux/unaligned/generic.h> +#include <linux/unaligned/le_byteshift.h> +#include "tpm-utils.h" + +int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks) +{ + u32 supported = 0; + u32 pcr_banks = 0; + u32 active = 0; + int rc; + + rc = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks); + if (rc) + return rc; + + *active_pcr_banks = active; + + return 0; +} + +u32 tcg2_event_get_size(struct tpml_digest_values *digest_list) +{ + u32 len; + size_t i; + + len = offsetof(struct tcg_pcr_event2, digests); + len += offsetof(struct tpml_digest_values, digests); + for (i = 0; i < digest_list->count; ++i) { + u16 l = tpm2_algorithm_to_len(digest_list->digests[i].hash_alg); + + if (!l) + continue; + + len += l + offsetof(struct tpmt_ha, digest); + } + len += sizeof(u32); + + return len; +} + +int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length, + struct tpml_digest_values *digest_list) +{ + u8 final[sizeof(union tpmu_ha)]; + sha256_context ctx_256; + sha512_context ctx_512; + sha1_context ctx; + u32 active; + size_t i; + u32 len; + int rc; + + rc = tcg2_get_active_pcr_banks(dev, &active); + if (rc) + return rc; + + digest_list->count = 0; + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { + if (!(active & hash_algo_list[i].hash_mask)) + continue; + + switch (hash_algo_list[i].hash_alg) { + case TPM2_ALG_SHA1: + sha1_starts(&ctx); + sha1_update(&ctx, input, length); + sha1_finish(&ctx, final); + len = TPM2_SHA1_DIGEST_SIZE; + break; + case TPM2_ALG_SHA256: + sha256_starts(&ctx_256); + sha256_update(&ctx_256, input, length); + sha256_finish(&ctx_256, final); + len = TPM2_SHA256_DIGEST_SIZE; + break; + case TPM2_ALG_SHA384: + sha384_starts(&ctx_512); + sha384_update(&ctx_512, input, length); + sha384_finish(&ctx_512, final); + len = TPM2_SHA384_DIGEST_SIZE; + break; + case TPM2_ALG_SHA512: + sha512_starts(&ctx_512); + sha512_update(&ctx_512, input, length); + sha512_finish(&ctx_512, final); + len = TPM2_SHA512_DIGEST_SIZE; + break; + default: + printf("%s: unsupported algorithm %x\n", __func__, + hash_algo_list[i].hash_alg); + continue; + } + + digest_list->digests[digest_list->count].hash_alg = + hash_algo_list[i].hash_alg; + memcpy(&digest_list->digests[digest_list->count].digest, final, + len); + digest_list->count++; + } + + return 0; +} + +void tcg2_log_append(u32 pcr_index, u32 event_type, + struct tpml_digest_values *digest_list, u32 size, + const u8 *event, u8 *log) +{ + size_t len; + size_t pos; + u32 i; + + pos = offsetof(struct tcg_pcr_event2, pcr_index); + put_unaligned_le32(pcr_index, log); + pos = offsetof(struct tcg_pcr_event2, event_type); + put_unaligned_le32(event_type, log + pos); + pos = offsetof(struct tcg_pcr_event2, digests) + + offsetof(struct tpml_digest_values, count); + put_unaligned_le32(digest_list->count, log + pos); + + pos = offsetof(struct tcg_pcr_event2, digests) + + offsetof(struct tpml_digest_values, digests); + for (i = 0; i < digest_list->count; ++i) { + u16 hash_alg = digest_list->digests[i].hash_alg; + + len = tpm2_algorithm_to_len(hash_alg); + if (!len) + continue; + + pos += offsetof(struct tpmt_ha, hash_alg); + put_unaligned_le16(hash_alg, log + pos); + pos += offsetof(struct tpmt_ha, digest); + memcpy(log + pos, (u8 *)&digest_list->digests[i].digest, len); + pos += len; + } + + put_unaligned_le32(size, log + pos); + pos += sizeof(u32); + memcpy(log + pos, event, size); +} + +static int tcg2_log_append_check(struct tcg2_event_log *elog, u32 pcr_index, + u32 event_type, + struct tpml_digest_values *digest_list, + u32 size, const u8 *event) +{ + u32 event_size; + u8 *log; + + event_size = size + tcg2_event_get_size(digest_list); + if (elog->log_position + event_size > elog->log_size) { + printf("%s: log too large: %u + %u > %u\n", __func__, + elog->log_position, event_size, elog->log_size); + return -ENOBUFS; + } + + log = elog->log + elog->log_position; + elog->log_position += event_size; + + tcg2_log_append(pcr_index, event_type, digest_list, size, event, log); + + return 0; +} + +static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog) +{ + struct tcg_efi_spec_id_event *ev; + struct tcg_pcr_event *log; + u32 event_size; + u32 count = 0; + u32 log_size; + u32 active; + size_t i; + u16 len; + int rc; + + rc = tcg2_get_active_pcr_banks(dev, &active); + if (rc) + return rc; + + event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes); + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { + if (!(active & hash_algo_list[i].hash_mask)) + continue; + + switch (hash_algo_list[i].hash_alg) { + case TPM2_ALG_SHA1: + case TPM2_ALG_SHA256: + case TPM2_ALG_SHA384: + case TPM2_ALG_SHA512: + count++; + break; + default: + continue; + } + } + + event_size += 1 + + (sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count); + log_size = offsetof(struct tcg_pcr_event, event) + event_size; + + if (log_size > elog->log_size) { + printf("%s: log too large: %u > %u\n", __func__, log_size, + elog->log_size); + return -ENOBUFS; + } + + log = (struct tcg_pcr_event *)elog->log; + put_unaligned_le32(0, &log->pcr_index); + put_unaligned_le32(EV_NO_ACTION, &log->event_type); + memset(&log->digest, 0, sizeof(log->digest)); + put_unaligned_le32(event_size, &log->event_size); + + ev = (struct tcg_efi_spec_id_event *)log->event; + strlcpy((char *)ev->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, + sizeof(ev->signature)); + put_unaligned_le32(0, &ev->platform_class); + ev->spec_version_minor = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2; + ev->spec_version_major = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2; + ev->spec_errata = TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_ERRATA_TPM2; + ev->uintn_size = sizeof(size_t) / sizeof(u32); + put_unaligned_le32(count, &ev->number_of_algorithms); + + count = 0; + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { + if (!(active & hash_algo_list[i].hash_mask)) + continue; + + len = hash_algo_list[i].hash_len; + if (!len) + continue; + + put_unaligned_le16(hash_algo_list[i].hash_alg, + &ev->digest_sizes[count].algorithm_id); + put_unaligned_le16(len, &ev->digest_sizes[count].digest_size); + count++; + } + + *((u8 *)ev + (event_size - 1)) = 0; + elog->log_position = log_size; + + return 0; +} + +static int tcg2_replay_eventlog(struct tcg2_event_log *elog, + struct udevice *dev, + struct tpml_digest_values *digest_list, + u32 log_position) +{ + const u32 offset = offsetof(struct tcg_pcr_event2, digests) + + offsetof(struct tpml_digest_values, digests); + u32 event_size; + u32 count; + u16 algo; + u32 pcr; + u32 pos; + u16 len; + u8 *log; + int rc; + u32 i; + + while (log_position + offset < elog->log_size) { + log = elog->log + log_position; + + pos = offsetof(struct tcg_pcr_event2, pcr_index); + pcr = get_unaligned_le32(log + pos); + pos = offsetof(struct tcg_pcr_event2, event_type); + if (!get_unaligned_le32(log + pos)) + return 0; + + pos = offsetof(struct tcg_pcr_event2, digests) + + offsetof(struct tpml_digest_values, count); + count = get_unaligned_le32(log + pos); + if (count > ARRAY_SIZE(hash_algo_list) || + (digest_list->count && digest_list->count != count)) + return 0; + + pos = offsetof(struct tcg_pcr_event2, digests) + + offsetof(struct tpml_digest_values, digests); + for (i = 0; i < count; ++i) { + pos += offsetof(struct tpmt_ha, hash_alg); + if (log_position + pos + sizeof(u16) >= elog->log_size) + return 0; + + algo = get_unaligned_le16(log + pos); + pos += offsetof(struct tpmt_ha, digest); + switch (algo) { + case TPM2_ALG_SHA1: + case TPM2_ALG_SHA256: + case TPM2_ALG_SHA384: + case TPM2_ALG_SHA512: + len = tpm2_algorithm_to_len(algo); + break; + default: + return 0; + } + + if (digest_list->count) { + if (algo != digest_list->digests[i].hash_alg || + log_position + pos + len >= elog->log_size) + return 0; + + memcpy(digest_list->digests[i].digest.sha512, + log + pos, len); + } + + pos += len; + } + + if (log_position + pos + sizeof(u32) >= elog->log_size) + return 0; + + event_size = get_unaligned_le32(log + pos); + pos += event_size + sizeof(u32); + if (log_position + pos > elog->log_size) + return 0; + + if (digest_list->count) { + rc = tcg2_pcr_extend(dev, pcr, digest_list); + if (rc) + return rc; + } + + log_position += pos; + } + + elog->log_position = log_position; + elog->found = true; + return 0; +} + +static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog) +{ + struct tpml_digest_values digest_list; + struct tcg_efi_spec_id_event *event; + struct tcg_pcr_event *log; + u32 log_active; + u32 calc_size; + u32 active; + u32 count; + u32 evsz; + u32 mask; + u16 algo; + u16 len; + int rc; + u32 i; + u16 j; + + if (elog->log_size <= offsetof(struct tcg_pcr_event, event)) + return 0; + + log = (struct tcg_pcr_event *)elog->log; + if (get_unaligned_le32(&log->pcr_index) != 0 || + get_unaligned_le32(&log->event_type) != EV_NO_ACTION) + return 0; + + for (i = 0; i < sizeof(log->digest); i++) { + if (log->digest[i]) + return 0; + } + + evsz = get_unaligned_le32(&log->event_size); + if (evsz < offsetof(struct tcg_efi_spec_id_event, digest_sizes) || + evsz + offsetof(struct tcg_pcr_event, event) > elog->log_size) + return 0; + + event = (struct tcg_efi_spec_id_event *)log->event; + if (memcmp(event->signature, TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03, + sizeof(TCG_EFI_SPEC_ID_EVENT_SIGNATURE_03))) + return 0; + + if (event->spec_version_minor != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MINOR_TPM2 || + event->spec_version_major != TCG_EFI_SPEC_ID_EVENT_SPEC_VERSION_MAJOR_TPM2) + return 0; + + count = get_unaligned_le32(&event->number_of_algorithms); + if (count > ARRAY_SIZE(hash_algo_list)) + return 0; + + calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) + + (sizeof(struct tcg_efi_spec_id_event_algorithm_size) * count) + + 1; + if (evsz != calc_size) + return 0; + + rc = tcg2_get_active_pcr_banks(dev, &active); + if (rc) + return rc; + + digest_list.count = 0; + log_active = 0; + + for (i = 0; i < count; ++i) { + algo = get_unaligned_le16(&event->digest_sizes[i].algorithm_id); + mask = tcg2_algorithm_to_mask(algo); + + if (!(active & mask)) + return 0; + + switch (algo) { + case TPM2_ALG_SHA1: + case TPM2_ALG_SHA256: + case TPM2_ALG_SHA384: + case TPM2_ALG_SHA512: + len = get_unaligned_le16(&event->digest_sizes[i].digest_size); + if (tpm2_algorithm_to_len(algo) != len) + return 0; + digest_list.digests[digest_list.count++].hash_alg = algo; + break; + default: + return 0; + } + + log_active |= mask; + } + + /* Ensure the previous firmware extended all the PCRs. */ + if (log_active != active) + return 0; + + /* Read PCR0 to check if previous firmware extended the PCRs or not. */ + rc = tcg2_pcr_read(dev, 0, &digest_list); + if (rc) + return rc; + + for (i = 0; i < digest_list.count; ++i) { + len = tpm2_algorithm_to_len(digest_list.digests[i].hash_alg); + for (j = 0; j < len; ++j) { + if (digest_list.digests[i].digest.sha512[j]) + break; + } + + /* PCR is non-zero; it has been extended, so skip extending. */ + if (j != len) { + digest_list.count = 0; + break; + } + } + + return tcg2_replay_eventlog(elog, dev, &digest_list, + offsetof(struct tcg_pcr_event, event) + + evsz); +} + +int tcg2_pcr_extend(struct udevice *dev, u32 pcr_index, + struct tpml_digest_values *digest_list) +{ + u32 rc; + u32 i; + + for (i = 0; i < digest_list->count; i++) { + u32 alg = digest_list->digests[i].hash_alg; + + rc = tpm2_pcr_extend(dev, pcr_index, alg, + (u8 *)&digest_list->digests[i].digest, + tpm2_algorithm_to_len(alg)); + if (rc) { + printf("%s: error pcr:%u alg:%08x\n", __func__, + pcr_index, alg); + return rc; + } + } + + return 0; +} + +int tcg2_pcr_read(struct udevice *dev, u32 pcr_index, + struct tpml_digest_values *digest_list) +{ + struct tpm_chip_priv *priv; + u32 rc; + u32 i; + + priv = dev_get_uclass_priv(dev); + if (!priv) + return -ENODEV; + + for (i = 0; i < digest_list->count; i++) { + u32 alg = digest_list->digests[i].hash_alg; + u8 *digest = (u8 *)&digest_list->digests[i].digest; + + rc = tpm2_pcr_read(dev, pcr_index, priv->pcr_select_min, alg, + digest, tpm2_algorithm_to_len(alg), NULL); + if (rc) { + printf("%s: error pcr:%u alg:%08x\n", __func__, + pcr_index, alg); + return rc; + } + } + + return 0; +} + +int tcg2_measure_data(struct udevice *dev, struct tcg2_event_log *elog, + u32 pcr_index, u32 size, const u8 *data, u32 event_type, + u32 event_size, const u8 *event) +{ + struct tpml_digest_values digest_list; + int rc; + + if (data) + rc = tcg2_create_digest(dev, data, size, &digest_list); + else + rc = tcg2_create_digest(dev, event, event_size, &digest_list); + if (rc) + return rc; + + rc = tcg2_pcr_extend(dev, pcr_index, &digest_list); + if (rc) + return rc; + + return tcg2_log_append_check(elog, pcr_index, event_type, &digest_list, + event_size, event); +} + +int tcg2_log_prepare_buffer(struct udevice *dev, struct tcg2_event_log *elog, + bool ignore_existing_log) +{ + struct tcg2_event_log log; + int rc; + + elog->log_position = 0; + elog->found = false; + + rc = tcg2_platform_get_log(dev, (void **)&log.log, &log.log_size); + if (!rc) { + log.log_position = 0; + log.found = false; + + if (!ignore_existing_log) { + rc = tcg2_log_parse(dev, &log); + if (rc) + return rc; + } + + if (elog->log_size) { + if (log.found) { + if (elog->log_size < log.log_position) + return -ENOBUFS; + + /* + * Copy the discovered log into the user buffer + * if there's enough space. + */ + memcpy(elog->log, log.log, log.log_position); + } + + unmap_physmem(log.log, MAP_NOCACHE); + } else { + elog->log = log.log; + elog->log_size = log.log_size; + } + + elog->log_position = log.log_position; + elog->found = log.found; + } + + /* + * Initialize the log buffer if no log was discovered and the buffer is + * valid. User's can pass in their own buffer as a fallback if no + * memory region is found. + */ + if (!elog->found && elog->log_size) + rc = tcg2_log_init(dev, elog); + + return rc; +} + +int tcg2_measurement_init(struct udevice **dev, struct tcg2_event_log *elog, + bool ignore_existing_log) +{ + int rc; + + rc = tcg2_platform_get_tpm2(dev); + if (rc) + return rc; + + rc = tpm_auto_start(*dev); + if (rc) + return rc; + + rc = tcg2_log_prepare_buffer(*dev, elog, ignore_existing_log); + if (rc) { + tcg2_measurement_term(*dev, elog, true); + return rc; + } + + rc = tcg2_measure_event(*dev, elog, 0, EV_S_CRTM_VERSION, + strlen(version_string) + 1, + (u8 *)version_string); + if (rc) { + tcg2_measurement_term(*dev, elog, true); + return rc; + } + + return 0; +} + +void tcg2_measurement_term(struct udevice *dev, struct tcg2_event_log *elog, + bool error) +{ + u32 event = error ? 0x1 : 0xffffffff; + int i; + + for (i = 0; i < 8; ++i) + tcg2_measure_event(dev, elog, i, EV_SEPARATOR, sizeof(event), + (const u8 *)&event); + + if (elog->log) + unmap_physmem(elog->log, MAP_NOCACHE); +} + +__weak int tcg2_platform_get_log(struct udevice *dev, void **addr, u32 *size) +{ + const __be32 *addr_prop; + const __be32 *size_prop; + int asize; + int ssize; + + *addr = NULL; + *size = 0; + + addr_prop = dev_read_prop(dev, "tpm_event_log_addr", &asize); + if (!addr_prop) + addr_prop = dev_read_prop(dev, "linux,sml-base", &asize); + + size_prop = dev_read_prop(dev, "tpm_event_log_size", &ssize); + if (!size_prop) + size_prop = dev_read_prop(dev, "linux,sml-size", &ssize); + + if (addr_prop && size_prop) { + u64 a = of_read_number(addr_prop, asize / sizeof(__be32)); + u64 s = of_read_number(size_prop, ssize / sizeof(__be32)); + + *addr = map_physmem(a, s, MAP_NOCACHE); + *size = (u32)s; + } else { + struct ofnode_phandle_args args; + phys_addr_t a; + fdt_size_t s; + + if (dev_read_phandle_with_args(dev, "memory-region", NULL, 0, + 0, &args)) + return -ENODEV; + + a = ofnode_get_addr_size(args.node, "reg", &s); + if (a == FDT_ADDR_T_NONE) + return -ENOMEM; + + *addr = map_physmem(a, s, MAP_NOCACHE); + *size = (u32)s; + } + + return 0; +} + +__weak int tcg2_platform_get_tpm2(struct udevice **dev) +{ + for_each_tpm_device(*dev) { + if (tpm_get_version(*dev) == TPM_V2) + return 0; + } + + return -ENODEV; +} + +u32 tcg2_algorithm_to_mask(enum tpm2_algorithms algo) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) { + if (hash_algo_list[i].hash_alg == algo) + return hash_algo_list[i].hash_mask; + } + + return 0; +} + +__weak void tcg2_platform_startup_error(struct udevice *dev, int rc) {}

efi_tcg2.h already includes tpm-v2.h. Remove it
Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- lib/efi_loader/efi_tcg2.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index b4915cab6be7..19fe4720ef48 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -16,7 +16,6 @@ #include <malloc.h> #include <smbios.h> #include <version_string.h> -#include <tpm-v2.h> #include <tpm_api.h> #include <u-boot/hash-checksum.h> #include <u-boot/sha1.h>

This function was used on measured boot to retrieve the number of active PCR banks and was designed to work with the TCG protocols. Since we now have the need to retrieve the active PCRs outside the measured boot context -- e.g use the in the command line, decouple the function.
Create one that will only adheres to TCG TSS2.0 [0] specification called tpm2_get_pcr_info() which can be used by the TPM2.0 APIs and a new one that is called from the measured boot context called tcg2_get_pcr_info()
[0] https://trustedcomputinggroup.org/wp-content/uploads/TSS_Overview_Common_Str...
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- include/tpm-v2.h | 16 ++++++--- include/tpm_tcg2.h | 13 +++++++ lib/efi_loader/efi_tcg2.c | 2 +- lib/tpm-v2.c | 73 +++++++++++++-------------------------- lib/tpm_tcg2.c | 38 +++++++++++++++++++- 5 files changed, 86 insertions(+), 56 deletions(-)
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index fc7c58204e58..aedf2c0f4f5c 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -522,14 +522,11 @@ u32 tpm2_get_capability(struct udevice *dev, u32 capability, u32 property, * tpm2_get_pcr_info() - get the supported, active PCRs and number of banks * * @dev: TPM device - * @supported_pcr: bitmask with the algorithms supported - * @active_pcr: bitmask with the active algorithms - * @pcr_banks: number of PCR banks + * @pcrs: struct tpml_pcr_selection of available PCRs * * @return 0 on success, code of operation or negative errno on failure */ -int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, - u32 *pcr_banks); +int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs);
/** * Issue a TPM2_DictionaryAttackLockReset command. @@ -715,4 +712,13 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); */ const char *tpm2_algorithm_name(enum tpm2_algorithms);
+/** + * tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs + * supports the algorithm add it on the active ones + * + * @selection: PCR selection structure + * Return: True if the algorithm is active + */ +bool tpm2_is_active_pcr(struct tpms_pcr_selection *selection); + #endif /* __TPM_V2_H */ diff --git a/include/tpm_tcg2.h b/include/tpm_tcg2.h index 4e4ea1e8067d..6519004cc410 100644 --- a/include/tpm_tcg2.h +++ b/include/tpm_tcg2.h @@ -93,6 +93,19 @@ struct tcg_pcr_event { u8 event[]; } __packed;
+/** + * tcg2_get_pcr_info() - get the supported, active PCRs and number of banks + * + * @dev: TPM device + * @supported_pcr: bitmask with the algorithms supported + * @active_pcr: bitmask with the active algorithms + * @pcr_banks: number of PCR banks + * + * @return 0 on success, code of operation or negative errno on failure + */ +int tcg2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, + u32 *pcr_banks); + /** * Crypto Agile Log Entry Format * diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 19fe4720ef48..ebbcd13bfbf6 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -279,7 +279,7 @@ efi_tcg2_get_capability(struct efi_tcg2_protocol *this, /* Supported and active PCRs */ capability->hash_algorithm_bitmap = 0; capability->active_pcr_banks = 0; - ret = tpm2_get_pcr_info(dev, &capability->hash_algorithm_bitmap, + ret = tcg2_get_pcr_info(dev, &capability->hash_algorithm_bitmap, &capability->active_pcr_banks, &capability->number_of_pcr_banks); if (ret) { diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 62ab804b4b38..36aace03cf4e 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -395,48 +395,26 @@ static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr) return 0; }
-static bool tpm2_is_active_pcr(struct tpms_pcr_selection *selection) -{ - int i; - - /* - * check the pcr_select. If at least one of the PCRs supports the - * algorithm add it on the active ones - */ - for (i = 0; i < selection->size_of_select; i++) { - if (selection->pcr_select[i]) - return true; - } - - return false; -} - -int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, - u32 *pcr_banks) +int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs) { u8 response[(sizeof(struct tpms_capability_data) - offsetof(struct tpms_capability_data, data))]; - struct tpml_pcr_selection pcrs; u32 num_pcr; size_t i; u32 ret;
- *supported_pcr = 0; - *active_pcr = 0; - *pcr_banks = 0; - memset(response, 0, sizeof(response)); ret = tpm2_get_capability(dev, TPM2_CAP_PCRS, 0, response, 1); if (ret) return ret;
- pcrs.count = get_unaligned_be32(response); + pcrs->count = get_unaligned_be32(response); /* * We only support 5 algorithms for now so check against that * instead of TPM2_NUM_PCR_BANKS */ - if (pcrs.count > ARRAY_SIZE(hash_algo_list) || - pcrs.count < 1) { - printf("%s: too many pcrs: %u\n", __func__, pcrs.count); + if (pcrs->count > ARRAY_SIZE(hash_algo_list) || + pcrs->count < 1) { + printf("%s: too many pcrs: %u\n", __func__, pcrs->count); return -EMSGSIZE; }
@@ -444,7 +422,7 @@ int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, if (ret) return ret;
- for (i = 0; i < pcrs.count; i++) { + for (i = 0; i < pcrs->count; i++) { /* * Definition of TPMS_PCR_SELECTION Structure * hash: u16 @@ -464,35 +442,20 @@ int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, hash_offset + offsetof(struct tpms_pcr_selection, pcr_select);
- pcrs.selection[i].hash = + pcrs->selection[i].hash = get_unaligned_be16(response + hash_offset); - pcrs.selection[i].size_of_select = + pcrs->selection[i].size_of_select = __get_unaligned_be(response + size_select_offset); - if (pcrs.selection[i].size_of_select > TPM2_PCR_SELECT_MAX) { + if (pcrs->selection[i].size_of_select > TPM2_PCR_SELECT_MAX) { printf("%s: pcrs selection too large: %u\n", __func__, - pcrs.selection[i].size_of_select); + pcrs->selection[i].size_of_select); return -ENOBUFS; } /* copy the array of pcr_select */ - memcpy(pcrs.selection[i].pcr_select, response + pcr_select_offset, - pcrs.selection[i].size_of_select); - } - - for (i = 0; i < pcrs.count; i++) { - u32 hash_mask = tcg2_algorithm_to_mask(pcrs.selection[i].hash); - - if (hash_mask) { - *supported_pcr |= hash_mask; - if (tpm2_is_active_pcr(&pcrs.selection[i])) - *active_pcr |= hash_mask; - } else { - printf("%s: unknown algorithm %x\n", __func__, - pcrs.selection[i].hash); - } + memcpy(pcrs->selection[i].pcr_select, response + pcr_select_offset, + pcrs->selection[i].size_of_select); }
- *pcr_banks = pcrs.count; - return 0; }
@@ -880,6 +843,18 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd, return 0; }
+bool tpm2_is_active_pcr(struct tpms_pcr_selection *selection) +{ + int i; + + for (i = 0; i < selection->size_of_select; i++) { + if (selection->pcr_select[i]) + return true; + } + + return false; +} + enum tpm2_algorithms tpm2_name_to_algorithm(const char *name) { size_t i; diff --git a/lib/tpm_tcg2.c b/lib/tpm_tcg2.c index 91b9612fd3f6..7f868cc88374 100644 --- a/lib/tpm_tcg2.c +++ b/lib/tpm_tcg2.c @@ -20,6 +20,42 @@ #include <linux/unaligned/le_byteshift.h> #include "tpm-utils.h"
+int tcg2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr, + u32 *pcr_banks) +{ + u8 response[(sizeof(struct tpms_capability_data) - + offsetof(struct tpms_capability_data, data))]; + struct tpml_pcr_selection pcrs; + size_t i; + u32 ret; + + *supported_pcr = 0; + *active_pcr = 0; + *pcr_banks = 0; + memset(response, 0, sizeof(response)); + + ret = tpm2_get_pcr_info(dev, &pcrs); + if (ret) + return ret; + + for (i = 0; i < pcrs.count; i++) { + u32 hash_mask = tcg2_algorithm_to_mask(pcrs.selection[i].hash); + + if (hash_mask) { + *supported_pcr |= hash_mask; + if (tpm2_is_active_pcr(&pcrs.selection[i])) + *active_pcr |= hash_mask; + } else { + printf("%s: unknown algorithm %x\n", __func__, + pcrs.selection[i].hash); + } + } + + *pcr_banks = pcrs.count; + + return 0; +} + int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks) { u32 supported = 0; @@ -27,7 +63,7 @@ int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks) u32 active = 0; int rc;
- rc = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks); + rc = tcg2_get_pcr_info(dev, &supported, &active, &pcr_banks); if (rc) return rc;

Simon reports that after enabling all algorithms on the TPM some boards fail since they don't have enough storage to accommodate the ~5KB growth.
The choice of hash algorithms is determined by the platform and the TPM configuration. Failing to cap a PCR in a bank which the platform left active is a security vulnerability. It might allow unsealing of secrets if an attacker can replay a good set of measurements into an unused bank.
If MEASURED_BOOT or EFI_TCG2_PROTOCOL is enabled our Kconfig will enable all supported hashing algorithms. We still want to allow users to add a TPM and not enable measured boot via EFI or bootm though and at the same time, control the compiled algorithms for size reasons.
So let's add a function tpm2_allow_extend() which checks the TPM active PCRs banks against the one U-Boot was compiled with. We only allow extending PCRs if the algorithms selected during build match the TPM configuration.
It's worth noting that this is only added for TPM2.0, since TPM1.2 is lacking a lot of code at the moment to read the available PCR banks. We unconditionally enable SHA1 when a TPM is selected, which is the only hashing algorithm v1.2 supports.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- boot/Kconfig | 4 ++++ include/tpm-v2.h | 59 +++++++++++++++++++++++++++++++++++------------- lib/Kconfig | 6 ++--- lib/tpm-v2.c | 40 +++++++++++++++++++++++++++++--- 4 files changed, 87 insertions(+), 22 deletions(-)
diff --git a/boot/Kconfig b/boot/Kconfig index 6f3096c15a6f..b061891e109c 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -734,6 +734,10 @@ config LEGACY_IMAGE_FORMAT config MEASURED_BOOT bool "Measure boot images and configuration when booting without EFI" depends on HASH && TPM_V2 + select SHA1 + select SHA256 + select SHA384 + select SHA512 help This option enables measurement of the boot process when booting without UEFI . Measurement involves creating cryptographic hashes diff --git a/include/tpm-v2.h b/include/tpm-v2.h index aedf2c0f4f5c..4fd19c52fd70 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -278,48 +278,40 @@ struct digest_info { #define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
static const struct digest_info hash_algo_list[] = { +#if IS_ENABLED(CONFIG_SHA1) { "sha1", TPM2_ALG_SHA1, TCG2_BOOT_HASH_ALG_SHA1, TPM2_SHA1_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA256) { "sha256", TPM2_ALG_SHA256, TCG2_BOOT_HASH_ALG_SHA256, TPM2_SHA256_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA384) { "sha384", TPM2_ALG_SHA384, TCG2_BOOT_HASH_ALG_SHA384, TPM2_SHA384_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA512) { "sha512", TPM2_ALG_SHA512, TCG2_BOOT_HASH_ALG_SHA512, TPM2_SHA512_DIGEST_SIZE, }, +#endif };
-static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a) -{ - switch (a) { - case TPM2_ALG_SHA1: - return TPM2_SHA1_DIGEST_SIZE; - case TPM2_ALG_SHA256: - return TPM2_SHA256_DIGEST_SIZE; - case TPM2_ALG_SHA384: - return TPM2_SHA384_DIGEST_SIZE; - case TPM2_ALG_SHA512: - return TPM2_SHA512_DIGEST_SIZE; - default: - return 0; - } -} - /* NV index attributes */ enum tpm_index_attrs { TPMA_NV_PPWRITE = 1UL << 0, @@ -712,6 +704,41 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); */ const char *tpm2_algorithm_name(enum tpm2_algorithms);
+/** + * tpm2_algorithm_to_len() - Return an algorithm length for supported algorithm id + * + * @algorithm_id: algorithm defined in enum tpm2_algorithms + * Return: len or 0 if not supported + */ +u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo); + +/* + * When measured boot is enabled via EFI or bootX commands all the algorithms + * above are selected by our Kconfigs. Due to U-Boots nature of being small there + * are cases where we need some functionality from the TPM -- e.g storage or RNG + * but we don't want to support measurements. + * + * The choice of hash algorithms are determined by the platform and the TPM + * configuration. Failing to cap a PCR in a bank which the platform left + * active is a security vulnerability. It permits the unsealing of secrets + * if an attacker can replay a good set of measurements into an unused bank. + * + * On top of that a previous stage bootloader (e.g TF-A), migh pass an eventlog + * since it doesn't have a TPM driver, which U-Boot needs to replace. The algorit h + * choice is a compile time option in that case and we need to make sure we conform. + * + * Add a variable here that sums the supported algorithms U-Boot was compiled + * with so we can refuse to do measurements if we don't support all of them + */ + +/** + * tpm2_allow_extend() - Check if extending PCRs is allowed and safe + * + * @dev: TPM device + * Return: true if allowed + */ +bool tpm2_allow_extend(struct udevice *dev); + /** * tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs * supports the algorithm add it on the active ones diff --git a/lib/Kconfig b/lib/Kconfig index 189e6eb31aa1..b3baa4b85b07 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -439,9 +439,6 @@ config TPM depends on DM imply DM_RNG select SHA1 - select SHA256 - select SHA384 - select SHA512 help This enables support for TPMs which can be used to provide security features for your board. The TPM can be connected via LPC or I2C @@ -449,6 +446,9 @@ config TPM command to interactive the TPM. Driver model support is provided for the low-level TPM interface, but only one TPM is supported at a time by the TPM library. + For size reasons only SHA1 is selected which is supported on TPM1.2. + If you want a fully functional TPM enable all hashing algorithms. + If you enabled measured boot all hashing algorithms are selected.
config SPL_TPM bool "Trusted Platform Module (TPM) Support in SPL" diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 36aace03cf4e..59e6cbafafaa 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -196,6 +196,11 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
if (!digest) return -EINVAL; + + if (!tpm2_allow_extend(dev)) { + log_err("Cannot extend PCRs if all the TPM enabled algorithms are not supported\n"); + return -EINVAL; + } /* * Fill the command structure starting from the first buffer: * - the digest @@ -409,11 +414,10 @@ int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs)
pcrs->count = get_unaligned_be32(response); /* - * We only support 5 algorithms for now so check against that + * We only support 4 algorithms for now so check against that * instead of TPM2_NUM_PCR_BANKS */ - if (pcrs->count > ARRAY_SIZE(hash_algo_list) || - pcrs->count < 1) { + if (pcrs->count > 4 || pcrs->count < 1) { printf("%s: too many pcrs: %u\n", __func__, pcrs->count); return -EMSGSIZE; } @@ -880,3 +884,33 @@ const char *tpm2_algorithm_name(enum tpm2_algorithms algo) return ""; }
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) { + if (hash_algo_list[i].hash_alg == algo) + return hash_algo_list[i].hash_len; + } + + return 0; +} + +bool tpm2_allow_extend(struct udevice *dev) +{ + struct tpml_pcr_selection pcrs; + size_t i; + int rc; + + rc = tpm2_get_pcr_info(dev, &pcrs); + if (rc) + return false; + + for (i = 0; i < pcrs.count; i++) { + if (tpm2_is_active_pcr(&pcrs.selection[i]) && + !tpm2_algorithm_to_len(pcrs.selection[i].hash)) + return false; + } + + return true; +}

Hi Ilias,
On Sun, 23 Jun 2024 at 05:49, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Simon reports that after enabling all algorithms on the TPM some boards fail since they don't have enough storage to accommodate the ~5KB growth.
The choice of hash algorithms is determined by the platform and the TPM configuration. Failing to cap a PCR in a bank which the platform left active is a security vulnerability. It might allow unsealing of secrets if an attacker can replay a good set of measurements into an unused bank.
If MEASURED_BOOT or EFI_TCG2_PROTOCOL is enabled our Kconfig will enable all supported hashing algorithms. We still want to allow users to add a TPM and not enable measured boot via EFI or bootm though and at the same time, control the compiled algorithms for size reasons.
So let's add a function tpm2_allow_extend() which checks the TPM active PCRs banks against the one U-Boot was compiled with. We only allow extending PCRs if the algorithms selected during build match the TPM configuration.
It's worth noting that this is only added for TPM2.0, since TPM1.2 is lacking a lot of code at the moment to read the available PCR banks. We unconditionally enable SHA1 when a TPM is selected, which is the only hashing algorithm v1.2 supports.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
boot/Kconfig | 4 ++++ include/tpm-v2.h | 59 +++++++++++++++++++++++++++++++++++------------- lib/Kconfig | 6 ++--- lib/tpm-v2.c | 40 +++++++++++++++++++++++++++++--- 4 files changed, 87 insertions(+), 22 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org # chromebook-link
nits / thoughts for the future below
diff --git a/boot/Kconfig b/boot/Kconfig index 6f3096c15a6f..b061891e109c 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -734,6 +734,10 @@ config LEGACY_IMAGE_FORMAT config MEASURED_BOOT bool "Measure boot images and configuration when booting without EFI" depends on HASH && TPM_V2
select SHA1
select SHA256
select SHA384
select SHA512 help This option enables measurement of the boot process when booting without UEFI . Measurement involves creating cryptographic hashes
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index aedf2c0f4f5c..4fd19c52fd70 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -278,48 +278,40 @@ struct digest_info { #define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
static const struct digest_info hash_algo_list[] = { +#if IS_ENABLED(CONFIG_SHA1) { "sha1", TPM2_ALG_SHA1, TCG2_BOOT_HASH_ALG_SHA1, TPM2_SHA1_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA256) { "sha256", TPM2_ALG_SHA256, TCG2_BOOT_HASH_ALG_SHA256, TPM2_SHA256_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA384) { "sha384", TPM2_ALG_SHA384, TCG2_BOOT_HASH_ALG_SHA384, TPM2_SHA384_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA512) { "sha512",
This is a duplicate of common/hash.c (we can worry about all this later)
TPM2_ALG_SHA512, TCG2_BOOT_HASH_ALG_SHA512, TPM2_SHA512_DIGEST_SIZE,
so is this
},
+#endif };
-static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a) -{
switch (a) {
case TPM2_ALG_SHA1:
return TPM2_SHA1_DIGEST_SIZE;
case TPM2_ALG_SHA256:
return TPM2_SHA256_DIGEST_SIZE;
case TPM2_ALG_SHA384:
return TPM2_SHA384_DIGEST_SIZE;
case TPM2_ALG_SHA512:
return TPM2_SHA512_DIGEST_SIZE;
default:
return 0;
}
-}
/* NV index attributes */ enum tpm_index_attrs { TPMA_NV_PPWRITE = 1UL << 0, @@ -712,6 +704,41 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); */ const char *tpm2_algorithm_name(enum tpm2_algorithms);
+/**
- tpm2_algorithm_to_len() - Return an algorithm length for supported algorithm id
- @algorithm_id: algorithm defined in enum tpm2_algorithms
- Return: len or 0 if not supported
- */
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo);
+/*
- When measured boot is enabled via EFI or bootX commands all the algorithms
- above are selected by our Kconfigs. Due to U-Boots nature of being small there
U-Boot's
- are cases where we need some functionality from the TPM -- e.g storage or RNG
- but we don't want to support measurements.
- The choice of hash algorithms are determined by the platform and the TPM
- configuration. Failing to cap a PCR in a bank which the platform left
- active is a security vulnerability. It permits the unsealing of secrets
- if an attacker can replay a good set of measurements into an unused bank.
- On top of that a previous stage bootloader (e.g TF-A), migh pass an eventlog
might
- since it doesn't have a TPM driver, which U-Boot needs to replace. The algorit h
algorithm
- choice is a compile time option in that case and we need to make sure we conform.
- Add a variable here that sums the supported algorithms U-Boot was compiled
- with so we can refuse to do measurements if we don't support all of them
- */
+/**
- tpm2_allow_extend() - Check if extending PCRs is allowed and safe
- @dev: TPM device
- Return: true if allowed
- */
+bool tpm2_allow_extend(struct udevice *dev);
/**
- tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs
supports the algorithm add it on the active ones
diff --git a/lib/Kconfig b/lib/Kconfig index 189e6eb31aa1..b3baa4b85b07 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -439,9 +439,6 @@ config TPM depends on DM imply DM_RNG select SHA1
select SHA256
select SHA384
select SHA512 help This enables support for TPMs which can be used to provide security features for your board. The TPM can be connected via LPC or I2C
@@ -449,6 +446,9 @@ config TPM command to interactive the TPM. Driver model support is provided for the low-level TPM interface, but only one TPM is supported at a time by the TPM library.
For size reasons only SHA1 is selected which is supported on TPM1.2.
If you want a fully functional TPM enable all hashing algorithms.
If you enabled measured boot all hashing algorithms are selected.
config SPL_TPM bool "Trusted Platform Module (TPM) Support in SPL" diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 36aace03cf4e..59e6cbafafaa 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -196,6 +196,11 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
if (!digest) return -EINVAL;
if (!tpm2_allow_extend(dev)) {
log_err("Cannot extend PCRs if all the TPM enabled algorithms are not supported\n");
return -EINVAL;
} /* * Fill the command structure starting from the first buffer: * - the digest
@@ -409,11 +414,10 @@ int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs)
pcrs->count = get_unaligned_be32(response); /*
* We only support 5 algorithms for now so check against that
* We only support 4 algorithms for now so check against that * instead of TPM2_NUM_PCR_BANKS */
if (pcrs->count > ARRAY_SIZE(hash_algo_list) ||
pcrs->count < 1) {
if (pcrs->count > 4 || pcrs->count < 1) { printf("%s: too many pcrs: %u\n", __func__, pcrs->count); return -EMSGSIZE; }
@@ -880,3 +884,33 @@ const char *tpm2_algorithm_name(enum tpm2_algorithms algo) return ""; }
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo)
nit: return uint? There is no need to mask the register here
+{
size_t i;
for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
if (hash_algo_list[i].hash_alg == algo)
return hash_algo_list[i].hash_len;
}
return 0;
+}
At some point we could have a HASH_ALGOT variable in hash.h which encodes the hash algorithm, then some of this will be common
+bool tpm2_allow_extend(struct udevice *dev) +{
struct tpml_pcr_selection pcrs;
size_t i;
int rc;
rc = tpm2_get_pcr_info(dev, &pcrs);
if (rc)
return false;
for (i = 0; i < pcrs.count; i++) {
if (tpm2_is_active_pcr(&pcrs.selection[i]) &&
!tpm2_algorithm_to_len(pcrs.selection[i].hash))
return false;
}
return true;
+}
2.45.2
REgards, Simon

On Mon, 24 Jun 2024 at 00:52, Simon Glass sjg@chromium.org wrote:
Hi Ilias,
On Sun, 23 Jun 2024 at 05:49, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
Simon reports that after enabling all algorithms on the TPM some boards fail since they don't have enough storage to accommodate the ~5KB growth.
The choice of hash algorithms is determined by the platform and the TPM configuration. Failing to cap a PCR in a bank which the platform left active is a security vulnerability. It might allow unsealing of secrets if an attacker can replay a good set of measurements into an unused bank.
If MEASURED_BOOT or EFI_TCG2_PROTOCOL is enabled our Kconfig will enable all supported hashing algorithms. We still want to allow users to add a TPM and not enable measured boot via EFI or bootm though and at the same time, control the compiled algorithms for size reasons.
So let's add a function tpm2_allow_extend() which checks the TPM active PCRs banks against the one U-Boot was compiled with. We only allow extending PCRs if the algorithms selected during build match the TPM configuration.
It's worth noting that this is only added for TPM2.0, since TPM1.2 is lacking a lot of code at the moment to read the available PCR banks. We unconditionally enable SHA1 when a TPM is selected, which is the only hashing algorithm v1.2 supports.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
boot/Kconfig | 4 ++++ include/tpm-v2.h | 59 +++++++++++++++++++++++++++++++++++------------- lib/Kconfig | 6 ++--- lib/tpm-v2.c | 40 +++++++++++++++++++++++++++++--- 4 files changed, 87 insertions(+), 22 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org # chromebook-link
nits / thoughts for the future below
I'll fix the spelling errors before merging
diff --git a/boot/Kconfig b/boot/Kconfig index 6f3096c15a6f..b061891e109c 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -734,6 +734,10 @@ config LEGACY_IMAGE_FORMAT config MEASURED_BOOT bool "Measure boot images and configuration when booting without EFI" depends on HASH && TPM_V2
select SHA1
select SHA256
select SHA384
select SHA512 help This option enables measurement of the boot process when booting without UEFI . Measurement involves creating cryptographic hashes
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index aedf2c0f4f5c..4fd19c52fd70 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -278,48 +278,40 @@ struct digest_info { #define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
static const struct digest_info hash_algo_list[] = { +#if IS_ENABLED(CONFIG_SHA1) { "sha1", TPM2_ALG_SHA1, TCG2_BOOT_HASH_ALG_SHA1, TPM2_SHA1_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA256) { "sha256", TPM2_ALG_SHA256, TCG2_BOOT_HASH_ALG_SHA256, TPM2_SHA256_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA384) { "sha384", TPM2_ALG_SHA384, TCG2_BOOT_HASH_ALG_SHA384, TPM2_SHA384_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA512) { "sha512",
This is a duplicate of common/hash.c (we can worry about all this later)
The name and length are. TPM2_ALG_SHAXXX is what the device returns though when probed for available algorithms and since those values are not maskable, TCG defined its masks .... TCG2_BOOT_HASH_ALG_SHA512 etc. This is unfortunate but I can't immediately think of an elegant way to combine those.
TPM2_ALG_SHA512, TCG2_BOOT_HASH_ALG_SHA512, TPM2_SHA512_DIGEST_SIZE,
so is this
},
+#endif };
-static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a) -{
switch (a) {
case TPM2_ALG_SHA1:
return TPM2_SHA1_DIGEST_SIZE;
case TPM2_ALG_SHA256:
return TPM2_SHA256_DIGEST_SIZE;
case TPM2_ALG_SHA384:
return TPM2_SHA384_DIGEST_SIZE;
case TPM2_ALG_SHA512:
return TPM2_SHA512_DIGEST_SIZE;
default:
return 0;
}
-}
/* NV index attributes */ enum tpm_index_attrs { TPMA_NV_PPWRITE = 1UL << 0, @@ -712,6 +704,41 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); */ const char *tpm2_algorithm_name(enum tpm2_algorithms);
+/**
- tpm2_algorithm_to_len() - Return an algorithm length for supported algorithm id
- @algorithm_id: algorithm defined in enum tpm2_algorithms
- Return: len or 0 if not supported
- */
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo);
+/*
- When measured boot is enabled via EFI or bootX commands all the algorithms
- above are selected by our Kconfigs. Due to U-Boots nature of being small there
U-Boot's
- are cases where we need some functionality from the TPM -- e.g storage or RNG
- but we don't want to support measurements.
- The choice of hash algorithms are determined by the platform and the TPM
- configuration. Failing to cap a PCR in a bank which the platform left
- active is a security vulnerability. It permits the unsealing of secrets
- if an attacker can replay a good set of measurements into an unused bank.
- On top of that a previous stage bootloader (e.g TF-A), migh pass an eventlog
might
- since it doesn't have a TPM driver, which U-Boot needs to replace. The algorit h
algorithm
- choice is a compile time option in that case and we need to make sure we conform.
- Add a variable here that sums the supported algorithms U-Boot was compiled
- with so we can refuse to do measurements if we don't support all of them
- */
+/**
- tpm2_allow_extend() - Check if extending PCRs is allowed and safe
- @dev: TPM device
- Return: true if allowed
- */
+bool tpm2_allow_extend(struct udevice *dev);
/**
- tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs
supports the algorithm add it on the active ones
diff --git a/lib/Kconfig b/lib/Kconfig index 189e6eb31aa1..b3baa4b85b07 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -439,9 +439,6 @@ config TPM depends on DM imply DM_RNG select SHA1
select SHA256
select SHA384
select SHA512 help This enables support for TPMs which can be used to provide security features for your board. The TPM can be connected via LPC or I2C
@@ -449,6 +446,9 @@ config TPM command to interactive the TPM. Driver model support is provided for the low-level TPM interface, but only one TPM is supported at a time by the TPM library.
For size reasons only SHA1 is selected which is supported on TPM1.2.
If you want a fully functional TPM enable all hashing algorithms.
If you enabled measured boot all hashing algorithms are selected.
config SPL_TPM bool "Trusted Platform Module (TPM) Support in SPL" diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 36aace03cf4e..59e6cbafafaa 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -196,6 +196,11 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
if (!digest) return -EINVAL;
if (!tpm2_allow_extend(dev)) {
log_err("Cannot extend PCRs if all the TPM enabled algorithms are not supported\n");
return -EINVAL;
} /* * Fill the command structure starting from the first buffer: * - the digest
@@ -409,11 +414,10 @@ int tpm2_get_pcr_info(struct udevice *dev, struct tpml_pcr_selection *pcrs)
pcrs->count = get_unaligned_be32(response); /*
* We only support 5 algorithms for now so check against that
* We only support 4 algorithms for now so check against that * instead of TPM2_NUM_PCR_BANKS */
if (pcrs->count > ARRAY_SIZE(hash_algo_list) ||
pcrs->count < 1) {
if (pcrs->count > 4 || pcrs->count < 1) { printf("%s: too many pcrs: %u\n", __func__, pcrs->count); return -EMSGSIZE; }
@@ -880,3 +884,33 @@ const char *tpm2_algorithm_name(enum tpm2_algorithms algo) return ""; }
+u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo)
nit: return uint? There is no need to mask the register here
+{
size_t i;
for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
if (hash_algo_list[i].hash_alg == algo)
return hash_algo_list[i].hash_len;
}
return 0;
+}
At some point we could have a HASH_ALGOT variable in hash.h which encodes the hash algorithm, then some of this will be common
Yes, I was toying around with the idea of creating a mask with the supported algorithms. We could even reuse the masking the TCG defines. There's nothing special to this function tbh, so we can move it in common/hash.c instead as well. But I'll pick this as-is for now and plan for a wider refactoring of all the hashing support we have. There are a lot of places we redefine those and we shouldn't.
Thanks /Ilias
+bool tpm2_allow_extend(struct udevice *dev) +{
struct tpml_pcr_selection pcrs;
size_t i;
int rc;
rc = tpm2_get_pcr_info(dev, &pcrs);
if (rc)
return false;
for (i = 0; i < pcrs.count; i++) {
if (tpm2_is_active_pcr(&pcrs.selection[i]) &&
!tpm2_algorithm_to_len(pcrs.selection[i].hash))
return false;
}
return true;
+}
2.45.2
REgards, Simon
participants (2)
-
Ilias Apalodimas
-
Simon Glass