With CONFIG_OPTEE_TA_AVB use the trusted application AVB provided by OP-TEE to manage rollback indexes and device lock status.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org --- common/avb_verify.c | 118 ++++++++++++++++++++++++++++++++++++++++++- doc/README.avb2 | 13 +++++ include/avb_verify.h | 4 ++ 3 files changed, 134 insertions(+), 1 deletion(-)
diff --git a/common/avb_verify.c b/common/avb_verify.c index 3a1282a09204..c2248c92514e 100644 --- a/common/avb_verify.c +++ b/common/avb_verify.c @@ -10,6 +10,8 @@ #include <image.h> #include <malloc.h> #include <part.h> +#include <tee.h> +#include <tee/optee_ta_avb.h>
const unsigned char avb_root_pub[1032] = { 0x0, 0x0, 0x10, 0x0, 0x55, 0xd9, 0x4, 0xad, 0xd8, 0x4, @@ -594,6 +596,65 @@ static AvbIOResult validate_vbmeta_public_key(AvbOps *ops, return AVB_IO_RESULT_OK; }
+#ifdef CONFIG_OPTEE_TA_AVB +static int get_open_session(struct AvbOpsData *ops_data) +{ + struct udevice *tee = NULL; + + while (!ops_data->tee) { + const struct tee_optee_ta_uuid uuid = TA_AVB_UUID; + struct tee_open_session_arg arg; + int rc; + + tee = tee_find_device(tee, NULL, NULL, NULL); + if (!tee) + return -ENODEV; + + memset(&arg, 0, sizeof(arg)); + tee_optee_ta_uuid_to_octets(arg.uuid, &uuid); + rc = tee_open_session(tee, &arg, 0, NULL); + if (!rc) { + ops_data->tee = tee; + ops_data->session = arg.session; + } + } + + return 0; +} + +static AvbIOResult invoke_func(struct AvbOpsData *ops_data, u32 func, + ulong num_param, struct tee_param *param) +{ + struct tee_invoke_arg arg; + + if (get_open_session(ops_data)) + return AVB_IO_RESULT_ERROR_IO; + + memset(&arg, 0, sizeof(arg)); + arg.func = func; + arg.session = ops_data->session; + + if (tee_invoke_func(ops_data->tee, &arg, num_param, param)) + return AVB_IO_RESULT_ERROR_IO; + switch (arg.ret) { + case TEE_SUCCESS: + return AVB_IO_RESULT_OK; + case TEE_ERROR_OUT_OF_MEMORY: + return AVB_IO_RESULT_ERROR_OOM; + case TEE_ERROR_TARGET_DEAD: + /* + * The TA has paniced, close the session to reload the TA + * for the next request. + */ + tee_close_session(ops_data->tee, ops_data->session); + ops_data->tee = NULL; + return AVB_IO_RESULT_ERROR_IO; + default: + return AVB_IO_RESULT_ERROR_IO; + } +} +#endif + /** * read_rollback_index() - gets the rollback index corresponding to the * location of given by @out_rollback_index. @@ -609,6 +670,7 @@ static AvbIOResult read_rollback_index(AvbOps *ops, size_t rollback_index_slot, u64 *out_rollback_index) { +#ifndef CONFIG_OPTEE_TA_AVB /* For now we always return 0 as the stored rollback index. */ printf("%s not supported yet\n", __func__);
@@ -616,6 +678,27 @@ static AvbIOResult read_rollback_index(AvbOps *ops, *out_rollback_index = 0;
return AVB_IO_RESULT_OK; +#else + AvbIOResult rc; + struct tee_param param[2]; + + if (rollback_index_slot >= TA_AVB_MAX_ROLLBACK_LOCATIONS) + return AVB_IO_RESULT_ERROR_NO_SUCH_VALUE; + + memset(param, 0, sizeof(param)); + param[0].attr = TEE_PARAM_ATTR_TYPE_VALUE_INPUT; + param[0].u.value.a = rollback_index_slot; + param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT; + + rc = invoke_func(ops->user_data, TA_AVB_CMD_READ_ROLLBACK_INDEX, + ARRAY_SIZE(param), param); + if (rc) + return rc; + + *out_rollback_index = (u64)param[1].u.value.a << 32 | + (u32)param[1].u.value.b; + return AVB_IO_RESULT_OK; +#endif }
/** @@ -633,10 +716,27 @@ static AvbIOResult write_rollback_index(AvbOps *ops, size_t rollback_index_slot, u64 rollback_index) { +#ifndef CONFIG_OPTEE_TA_AVB /* For now this is a no-op. */ printf("%s not supported yet\n", __func__);
return AVB_IO_RESULT_OK; +#else + struct tee_param param[2]; + + if (rollback_index_slot >= TA_AVB_MAX_ROLLBACK_LOCATIONS) + return AVB_IO_RESULT_ERROR_NO_SUCH_VALUE; + + memset(param, 0, sizeof(param)); + param[0].attr = TEE_PARAM_ATTR_TYPE_VALUE_INPUT; + param[0].u.value.a = rollback_index_slot; + param[1].attr = TEE_PARAM_ATTR_TYPE_VALUE_INPUT; + param[1].u.value.a = (u32)(rollback_index >> 32); + param[1].u.value.b = (u32)rollback_index; + + return invoke_func(ops->user_data, TA_AVB_CMD_WRITE_ROLLBACK_INDEX, + ARRAY_SIZE(param), param); +#endif }
/** @@ -652,6 +752,7 @@ static AvbIOResult write_rollback_index(AvbOps *ops, */ static AvbIOResult read_is_device_unlocked(AvbOps *ops, bool *out_is_unlocked) { +#ifndef CONFIG_OPTEE_TA_AVB /* For now we always return that the device is unlocked. */
printf("%s not supported yet\n", __func__); @@ -659,6 +760,16 @@ static AvbIOResult read_is_device_unlocked(AvbOps *ops, bool *out_is_unlocked) *out_is_unlocked = true;
return AVB_IO_RESULT_OK; +#else + AvbIOResult rc; + struct tee_param param = { .attr = TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT }; + + rc = invoke_func(ops->user_data, TA_AVB_CMD_READ_LOCK_STATE, 1, ¶m); + if (rc) + return rc; + *out_is_unlocked = !param.u.value.a; + return AVB_IO_RESULT_OK; +#endif }
/** @@ -737,6 +848,11 @@ void avb_ops_free(AvbOps *ops)
ops_data = ops->user_data;
- if (ops_data) + if (ops_data) { +#ifdef CONFIG_OPTEE_TA_AVB + if (ops_data->tee) + tee_close_session(ops_data->tee, ops_data->session); +#endif avb_free(ops_data); + } } diff --git a/doc/README.avb2 b/doc/README.avb2 index 120279fedbe2..a29cee1b6f50 100644 --- a/doc/README.avb2 +++ b/doc/README.avb2 @@ -18,6 +18,13 @@ Integrity of the bootloader (U-boot BLOB and environment) is out of scope. For additional details check: https://android.googlesource.com/platform/external/avb/+/master/README.md
+1.1. AVB using OP-TEE (optional) +--------------------------------- +If AVB is configured to use OP-TEE (see 4. below) rollback indexes and +device lock state are stored in RPMB. The RPMB partition is managed by +OP-TEE (https://www.op-tee.org/) which is a secure OS leveraging ARM +TrustZone. +
2. AVB 2.0 U-BOOT SHELL COMMANDS ----------------------------------- @@ -61,6 +68,12 @@ CONFIG_LIBAVB=y CONFIG_AVB_VERIFY=y CONFIG_CMD_AVB=y
+In addtion optionally if storing rollback indexes in RPMB with help of +OP-TEE: +CONFIG_TEE=y +CONFIG_OPTEE=y +CONFIG_OPTEE_TA_AVB=y +CONFIG_SUPPORT_EMMC_RPMB=y
Then add `avb verify` invocation to your android boot sequence of commands, e.g.: diff --git a/include/avb_verify.h b/include/avb_verify.h index eaa60f5393ef..a532a2331aea 100644 --- a/include/avb_verify.h +++ b/include/avb_verify.h @@ -27,6 +27,10 @@ struct AvbOpsData { struct AvbOps ops; int mmc_dev; enum avb_boot_state boot_state; +#ifdef CONFIG_OPTEE_TA_AVB + struct udevice *tee; + u32 session; +#endif };
struct mmc_part {