| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Permission is hereby granted, free of charge, to any person |
| * obtaining a copy of this software and associated documentation |
| * files (the "Software"), to deal in the Software without |
| * restriction, including without limitation the rights to use, copy, |
| * modify, merge, publish, distribute, sublicense, and/or sell copies |
| * of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be |
| * included in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| |
| #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) |
| #error "Never include this file directly, include libavb.h instead." |
| #endif |
| |
| #ifndef AVB_SLOT_VERIFY_H_ |
| #define AVB_SLOT_VERIFY_H_ |
| |
| #include "avb_ops.h" |
| #include "avb_vbmeta_image.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Return codes used in avb_slot_verify(), see that function for |
| * documentation for each field. |
| * |
| * Use avb_slot_verify_result_to_string() to get a textual |
| * representation usable for error/debug output. |
| */ |
| typedef enum { |
| AVB_SLOT_VERIFY_RESULT_OK, |
| AVB_SLOT_VERIFY_RESULT_ERROR_OOM, |
| AVB_SLOT_VERIFY_RESULT_ERROR_IO, |
| AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, |
| AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX, |
| AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED, |
| AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA, |
| AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION, |
| AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT |
| } AvbSlotVerifyResult; |
| |
| /* Various error handling modes for when verification fails using a |
| * hashtree at runtime inside the HLOS. |
| * |
| * AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE means that the OS |
| * will invalidate the current slot and restart. |
| * |
| * AVB_HASHTREE_ERROR_MODE_RESTART means that the OS will restart. |
| * |
| * AVB_HASHTREE_ERROR_MODE_EIO means that an EIO error will be |
| * returned to applications. |
| * |
| * AVB_HASHTREE_ERROR_MODE_LOGGING means that errors will be logged |
| * and corrupt data may be returned to applications. This mode should |
| * be used ONLY for diagnostics and debugging. It cannot be used |
| * unless AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is also |
| * used. |
| * |
| * AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO means that either |
| * AVB_HASHTREE_ERROR_MODE_RESTART or AVB_HASHTREE_ERROR_MODE_EIO is used |
| * depending on state. This mode implements a state machine whereby |
| * AVB_HASHTREE_ERROR_MODE_RESTART is used by default and when |
| * AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION is passed the |
| * mode transitions to AVB_HASHTREE_ERROR_MODE_EIO. When a new OS has been |
| * detected the device transitions back to the AVB_HASHTREE_ERROR_MODE_RESTART |
| * mode. To do this persistent storage is needed - specifically this means that |
| * the passed in AvbOps will need to have the read_persistent_value() and |
| * write_persistent_value() operations implemented. The name of the persistent |
| * value used is "avb.managed_verity_mode" and 32 bytes of storage is needed. |
| */ |
| typedef enum { |
| AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, |
| AVB_HASHTREE_ERROR_MODE_RESTART, |
| AVB_HASHTREE_ERROR_MODE_EIO, |
| AVB_HASHTREE_ERROR_MODE_LOGGING, |
| AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO |
| } AvbHashtreeErrorMode; |
| |
| /* Flags that influence how avb_slot_verify() works. |
| * |
| * If AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is NOT set then |
| * avb_slot_verify() will bail out as soon as an error is encountered |
| * and |out_data| is set only if AVB_SLOT_VERIFY_RESULT_OK is |
| * returned. |
| * |
| * Otherwise if AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is set |
| * avb_slot_verify() will continue verification efforts and |out_data| |
| * is also set if AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED, |
| * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, or |
| * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned. It is |
| * undefined which error is returned if more than one distinct error |
| * is encountered. It is guaranteed that AVB_SLOT_VERIFY_RESULT_OK is |
| * returned if, and only if, there are no errors. This mode is needed |
| * to boot valid but unverified slots when the device is unlocked. |
| * |
| * Also, if AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is set the |
| * contents loaded from |requested_partition| will be the contents of |
| * the entire partition instead of just the size specified in the hash |
| * descriptor. |
| * |
| * The AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION flag |
| * should be set if using AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO |
| * and the reason the boot loader is running is because the device |
| * was restarted by the dm-verity driver. |
| * |
| * If the AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION flag is set then |
| * data won't be loaded from the "vbmeta" partition and the |
| * |validate_vbmeta_public_key| operation is never called. Instead, the |
| * vbmeta structs in |requested_partitions| are loaded and processed and the |
| * |validate_public_key_for_partition| operation is called for each of these |
| * vbmeta structs. This flag is useful when booting into recovery on a device |
| * not using A/B - see section "Booting into recovery" in README.md for |
| * more information. |
| */ |
| typedef enum { |
| AVB_SLOT_VERIFY_FLAGS_NONE = 0, |
| AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR = (1 << 0), |
| AVB_SLOT_VERIFY_FLAGS_RESTART_CAUSED_BY_HASHTREE_CORRUPTION = (1 << 1), |
| AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION = (1 << 2), |
| } AvbSlotVerifyFlags; |
| |
| /* Get a textual representation of |result|. */ |
| const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result); |
| |
| /* Maximum number of rollback index locations supported. */ |
| /* Local modification for Estelle. See lib/fuchsia/README.estelle.md. */ |
| #define AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS 6 |
| |
| /* AvbPartitionData contains data loaded from partitions when using |
| * avb_slot_verify(). The |partition_name| field contains the name of |
| * the partition (without A/B suffix), |data| points to the loaded |
| * data which is |data_size| bytes long. If |preloaded| is set to true, |
| * this structure dose not own |data|. The caller of |avb_slot_verify| |
| * needs to make sure that the preloaded data outlives this |
| * |AvbPartitionData| structure. |
| * |
| * Note that this is strictly less than the partition size - it's only |
| * the image stored there, not the entire partition nor any of the |
| * metadata. |
| */ |
| typedef struct { |
| char* partition_name; |
| uint8_t* data; |
| size_t data_size; |
| bool preloaded; |
| } AvbPartitionData; |
| |
| /* AvbVBMetaData contains a vbmeta struct loaded from a partition when |
| * using avb_slot_verify(). The |partition_name| field contains the |
| * name of the partition (without A/B suffix), |vbmeta_data| points to |
| * the loaded data which is |vbmeta_size| bytes long. |
| * |
| * The |verify_result| field contains the result of |
| * avb_vbmeta_image_verify() on the data. This is guaranteed to be |
| * AVB_VBMETA_VERIFY_RESULT_OK for all vbmeta images if |
| * avb_slot_verify() returns AVB_SLOT_VERIFY_RESULT_OK. |
| * |
| * You can use avb_descriptor_get_all(), avb_descriptor_foreach(), and |
| * avb_vbmeta_image_header_to_host_byte_order() with this data. |
| */ |
| typedef struct { |
| char* partition_name; |
| uint8_t* vbmeta_data; |
| size_t vbmeta_size; |
| AvbVBMetaVerifyResult verify_result; |
| } AvbVBMetaData; |
| |
| /* AvbSlotVerifyData contains data needed to boot a particular slot |
| * and is returned by avb_slot_verify() if partitions in a slot are |
| * successfully verified. |
| * |
| * All data pointed to by this struct - including data in each item in |
| * the |partitions| array - will be freed when the |
| * avb_slot_verify_data_free() function is called. |
| * |
| * The |ab_suffix| field is the copy of the of |ab_suffix| field |
| * passed to avb_slot_verify(). It is the A/B suffix of the slot. This |
| * value includes the leading underscore - typical values are "" (if |
| * no slots are in use), "_a" (for the first slot), and "_b" (for the |
| * second slot). |
| * |
| * The VBMeta images that were checked are available in the |
| * |vbmeta_images| field. The field |num_vbmeta_images| contains the |
| * number of elements in this array. The first element - |
| * vbmeta_images[0] - is guaranteed to be from the partition with the |
| * top-level vbmeta struct. This is usually the "vbmeta" partition in |
| * the requested slot but if there is no "vbmeta" partition it can |
| * also be the "boot" partition. |
| * |
| * The partitions loaded and verified from from the slot are |
| * accessible in the |loaded_partitions| array. The field |
| * |num_loaded_partitions| contains the number of elements in this |
| * array. The order of partitions in this array may not necessarily be |
| * the same order as in the passed-in |requested_partitions| array. |
| * |
| * Rollback indexes for the verified slot are stored in the |
| * |rollback_indexes| field. Note that avb_slot_verify() will NEVER |
| * modify stored_rollback_index[n] locations e.g. it will never use |
| * the write_rollback_index() AvbOps operation. Instead it is the job |
| * of the caller of avb_slot_verify() to do this based on e.g. A/B |
| * policy and other factors. See libavb_ab/avb_ab_flow.c for an |
| * example of how to do this. |
| * |
| * The |cmdline| field is a NUL-terminated string in UTF-8 resulting |
| * from concatenating all |AvbKernelCmdlineDescriptor| and then |
| * performing proper substitution of the variables |
| * $(ANDROID_SYSTEM_PARTUUID), $(ANDROID_BOOT_PARTUUID), and |
| * $(ANDROID_VBMETA_PARTUUID) using the |
| * get_unique_guid_for_partition() operation in |AvbOps|. Additionally |
| * $(ANDROID_VERITY_MODE) will be replaced with the proper dm-verity |
| * option depending on the value of |hashtree_error_mode|. |
| * |
| * Additionally, the |cmdline| field will have the following kernel |
| * command-line options set (unless verification is disabled, see |
| * below): |
| * |
| * androidboot.veritymode: This is set to 'disabled' if the |
| * AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED flag is set in top-level |
| * vbmeta struct. Otherwise it is set to 'enforcing' if the |
| * passed-in hashtree error mode is AVB_HASHTREE_ERROR_MODE_RESTART |
| * or AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, 'eio' if it's |
| * set to AVB_HASHTREE_ERROR_MODE_EIO, and 'logging' if it's set to |
| * AVB_HASHTREE_ERROR_MODE_LOGGING. |
| * |
| * androidboot.veritymode.managed: This is set to 'yes' only |
| * if hashtree validation isn't disabled and the passed-in hashtree |
| * error mode is AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO. |
| * |
| * androidboot.vbmeta.invalidate_on_error: This is set to 'yes' only |
| * if hashtree validation isn't disabled and the passed-in hashtree |
| * error mode is AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE. |
| * |
| * androidboot.vbmeta.device_state: set to "locked" or "unlocked" |
| * depending on the result of the result of AvbOps's |
| * read_is_unlocked() function. |
| * |
| * androidboot.vbmeta.{hash_alg, size, digest}: Will be set to |
| * the digest of all images in |vbmeta_images|. |
| * |
| * androidboot.vbmeta.device: This is set to the value |
| * PARTUUID=$(ANDROID_VBMETA_PARTUUID) before substitution so it |
| * will end up pointing to the vbmeta partition for the verified |
| * slot. If there is no vbmeta partition it will point to the boot |
| * partition of the verified slot. If the flag |
| * AVB_SLOT_VERIFY_FLAGS_NO_VBMETA_PARTITION is used, this is not |
| * set. |
| * |
| * androidboot.vbmeta.avb_version: This is set to the decimal value |
| * of AVB_VERSION_MAJOR followed by a dot followed by the decimal |
| * value of AVB_VERSION_MINOR, for example "1.0" or "1.4". This |
| * version number represents the vbmeta file format version |
| * supported by libavb copy used in the boot loader. This is not |
| * necessarily the same version number of the on-disk metadata for |
| * the slot that was verified. |
| * |
| * Note that androidboot.slot_suffix is not set in the |cmdline| field |
| * in |AvbSlotVerifyData| - you will have to set this yourself. |
| * |
| * If the |AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED| flag is set |
| * in the top-level vbmeta struct then only the top-level vbmeta |
| * struct is verified and descriptors will not processed. The return |
| * value will be set accordingly (if this flag is set via 'avbctl |
| * disable-verification' then the return value will be |
| * |AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION|) and |
| * |AvbSlotVerifyData| is returned. Additionally all partitions in the |
| * |requested_partitions| are loaded and the |cmdline| field is set to |
| * "root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)" and the GUID for the |
| * appropriate system partition is substituted in. Note that none of |
| * the androidboot.* options mentioned above will be set. |
| * |
| * The |resolved_hashtree_error_mode| is the the value of the passed |
| * avb_slot_verify()'s |hashtree_error_mode| parameter except that it never has |
| * the value AVB_HASHTREE_ERROR_MODE_MANAGED_RESTART_AND_EIO. If this value was |
| * passed in, then the restart/eio state machine is used resulting in |
| * |resolved_hashtree_error_mode| being set to either |
| * AVB_HASHTREE_ERROR_MODE_RESTART or AVB_HASHTREE_ERROR_MODE_EIO. If set to |
| * AVB_HASHTREE_ERROR_MODE_EIO the boot loader should present a RED warning |
| * screen for the user to click through before continuing to boot. |
| * |
| * This struct may grow in the future without it being considered an |
| * ABI break. |
| */ |
| typedef struct { |
| char* ab_suffix; |
| AvbVBMetaData* vbmeta_images; |
| size_t num_vbmeta_images; |
| AvbPartitionData* loaded_partitions; |
| size_t num_loaded_partitions; |
| char* cmdline; |
| uint64_t rollback_indexes[AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS]; |
| AvbHashtreeErrorMode resolved_hashtree_error_mode; |
| } AvbSlotVerifyData; |
| |
| /* Calculates a digest of all vbmeta images in |data| using |
| * the digest indicated by |digest_type|. Stores the result |
| * in |out_digest| which must be large enough to hold a digest |
| * of the requested type. |
| */ |
| void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data, |
| AvbDigestType digest_type, |
| uint8_t* out_digest); |
| |
| /* Frees a |AvbSlotVerifyData| including all data it points to. */ |
| void avb_slot_verify_data_free(AvbSlotVerifyData* data); |
| |
| /* Performs a full verification of the slot identified by |ab_suffix| |
| * and load and verify the contents of the partitions whose name is in |
| * the NULL-terminated string array |requested_partitions| (each |
| * partition must use hash verification). If not using A/B, pass an |
| * empty string (e.g. "", not NULL) for |ab_suffix|. This parameter |
| * must include the leading underscore, for example "_a" should be |
| * used to refer to the first slot. |
| * |
| * Typically the |requested_partitions| array only contains a single |
| * item for the boot partition, 'boot'. |
| * |
| * Verification includes loading and verifying data from the 'vbmeta', |
| * the requested hash partitions, and possibly other partitions (with |
| * |ab_suffix| appended), inspecting rollback indexes, and checking if |
| * the public key used to sign the data is acceptable. The functions |
| * in |ops| will be used to do this. |
| * |
| * If |out_data| is not NULL, it will be set to a newly allocated |
| * |AvbSlotVerifyData| struct containing all the data needed to |
| * actually boot the slot. This data structure should be freed with |
| * avb_slot_verify_data_free() when you are done with it. See below |
| * for when this is returned. |
| * |
| * The |flags| parameter is used to influence the semantics of |
| * avb_slot_verify() - for example the |
| * AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR flag can be used to |
| * ignore verification errors which is something needed in the |
| * UNLOCKED state. See the AvbSlotVerifyFlags enumeration for details. |
| * |
| * The |hashtree_error_mode| parameter should be set to the desired error |
| * handling mode. See the AvbHashtreeErrorMode enumeration for details. |
| * |
| * Also note that |out_data| is never set if |
| * AVB_SLOT_VERIFY_RESULT_ERROR_OOM, AVB_SLOT_VERIFY_RESULT_ERROR_IO, |
| * or AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned. |
| * |
| * AVB_SLOT_VERIFY_RESULT_OK is returned if everything is verified |
| * correctly and all public keys are accepted. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED is returned if |
| * everything is verified correctly out but one or more public keys |
| * are not accepted. This includes the case where integrity data is |
| * not signed. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_OOM is returned if unable to |
| * allocate memory. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_IO is returned if an I/O error |
| * occurred while trying to load data or get a rollback index. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION is returned if the data |
| * did not verify, e.g. the digest didn't match or signature checks |
| * failed. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned if a |
| * rollback index was less than its stored value. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned if some |
| * of the metadata is invalid or inconsistent. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION is returned if |
| * some of the metadata requires a newer version of libavb than what |
| * is in use. |
| * |
| * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT is returned if the |
| * caller passed invalid parameters, for example trying to use |
| * AVB_HASHTREE_ERROR_MODE_LOGGING without |
| * AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR. |
| */ |
| AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, |
| const char* const* requested_partitions, |
| const char* ab_suffix, |
| AvbSlotVerifyFlags flags, |
| AvbHashtreeErrorMode hashtree_error_mode, |
| AvbSlotVerifyData** out_data); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* AVB_SLOT_VERIFY_H_ */ |