2 * Copyright (C) 2016 The Android Open Source Project
4 * SPDX-License-Identifier: MIT
7 #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION)
8 #error "Never include this file directly, include libavb.h instead."
11 #ifndef AVB_SLOT_VERIFY_H_
12 #define AVB_SLOT_VERIFY_H_
15 #include "avb_vbmeta_image.h"
21 /* Return codes used in avb_slot_verify(), see that function for
22 * documentation for each field.
24 * Use avb_slot_verify_result_to_string() to get a textual
25 * representation usable for error/debug output.
28 AVB_SLOT_VERIFY_RESULT_OK,
29 AVB_SLOT_VERIFY_RESULT_ERROR_OOM,
30 AVB_SLOT_VERIFY_RESULT_ERROR_IO,
31 AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION,
32 AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX,
33 AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED,
34 AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA,
35 AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION,
36 AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT
37 } AvbSlotVerifyResult;
39 /* Various error handling modes for when verification fails using a
40 * hashtree at runtime inside the HLOS.
42 * AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE means that the OS
43 * will invalidate the current slot and restart.
45 * AVB_HASHTREE_ERROR_MODE_RESTART means that the OS will restart.
47 * AVB_HASHTREE_ERROR_MODE_EIO means that an EIO error will be
48 * returned to applications.
50 * AVB_HASHTREE_ERROR_MODE_LOGGING means that errors will be logged
51 * and corrupt data may be returned to applications. This mode should
52 * be used ONLY for diagnostics and debugging. It cannot be used
53 * unless AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is also
57 AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE,
58 AVB_HASHTREE_ERROR_MODE_RESTART,
59 AVB_HASHTREE_ERROR_MODE_EIO,
60 AVB_HASHTREE_ERROR_MODE_LOGGING
61 } AvbHashtreeErrorMode;
63 /* Flags that influence how avb_slot_verify() works.
65 * If AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is NOT set then
66 * avb_slot_verify() will bail out as soon as an error is encountered
67 * and |out_data| is set only if AVB_SLOT_VERIFY_RESULT_OK is
70 * Otherwise if AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is set
71 * avb_slot_verify() will continue verification efforts and |out_data|
72 * is also set if AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED,
73 * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, or
74 * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned. It is
75 * undefined which error is returned if more than one distinct error
76 * is encountered. It is guaranteed that AVB_SLOT_VERIFY_RESULT_OK is
77 * returned if, and only if, there are no errors. This mode is needed
78 * to boot valid but unverified slots when the device is unlocked.
80 * Also, if AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR is set the
81 * contents loaded from |requested_partition| will be the contents of
82 * the entire partition instead of just the size specified in the hash
86 AVB_SLOT_VERIFY_FLAGS_NONE = 0,
87 AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR = (1 << 0)
90 /* Get a textual representation of |result|. */
91 const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result);
93 /* Maximum number of rollback index locations supported. */
94 #define AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS 32
96 /* AvbPartitionData contains data loaded from partitions when using
97 * avb_slot_verify(). The |partition_name| field contains the name of
98 * the partition (without A/B suffix), |data| points to the loaded
99 * data which is |data_size| bytes long. If |preloaded| is set to true,
100 * this structure dose not own |data|. The caller of |avb_slot_verify|
101 * needs to make sure that the preloaded data outlives this
102 * |AvbPartitionData| structure.
104 * Note that this is strictly less than the partition size - it's only
105 * the image stored there, not the entire partition nor any of the
109 char* partition_name;
115 /* AvbVBMetaData contains a vbmeta struct loaded from a partition when
116 * using avb_slot_verify(). The |partition_name| field contains the
117 * name of the partition (without A/B suffix), |vbmeta_data| points to
118 * the loaded data which is |vbmeta_size| bytes long.
120 * The |verify_result| field contains the result of
121 * avb_vbmeta_image_verify() on the data. This is guaranteed to be
122 * AVB_VBMETA_VERIFY_RESULT_OK for all vbmeta images if
123 * avb_slot_verify() returns AVB_SLOT_VERIFY_RESULT_OK.
125 * You can use avb_descriptor_get_all(), avb_descriptor_foreach(), and
126 * avb_vbmeta_image_header_to_host_byte_order() with this data.
129 char* partition_name;
130 uint8_t* vbmeta_data;
132 AvbVBMetaVerifyResult verify_result;
135 /* AvbSlotVerifyData contains data needed to boot a particular slot
136 * and is returned by avb_slot_verify() if partitions in a slot are
137 * successfully verified.
139 * All data pointed to by this struct - including data in each item in
140 * the |partitions| array - will be freed when the
141 * avb_slot_verify_data_free() function is called.
143 * The |ab_suffix| field is the copy of the of |ab_suffix| field
144 * passed to avb_slot_verify(). It is the A/B suffix of the slot. This
145 * value includes the leading underscore - typical values are "" (if
146 * no slots are in use), "_a" (for the first slot), and "_b" (for the
149 * The VBMeta images that were checked are available in the
150 * |vbmeta_images| field. The field |num_vbmeta_images| contains the
151 * number of elements in this array. The first element -
152 * vbmeta_images[0] - is guaranteed to be from the partition with the
153 * top-level vbmeta struct. This is usually the "vbmeta" partition in
154 * the requested slot but if there is no "vbmeta" partition it can
155 * also be the "boot" partition.
157 * The partitions loaded and verified from from the slot are
158 * accessible in the |loaded_partitions| array. The field
159 * |num_loaded_partitions| contains the number of elements in this
160 * array. The order of partitions in this array may not necessarily be
161 * the same order as in the passed-in |requested_partitions| array.
163 * Rollback indexes for the verified slot are stored in the
164 * |rollback_indexes| field. Note that avb_slot_verify() will NEVER
165 * modify stored_rollback_index[n] locations e.g. it will never use
166 * the write_rollback_index() AvbOps operation. Instead it is the job
167 * of the caller of avb_slot_verify() to do this based on e.g. A/B
168 * policy and other factors. See libavb_ab/avb_ab_flow.c for an
169 * example of how to do this.
171 * The |cmdline| field is a NUL-terminated string in UTF-8 resulting
172 * from concatenating all |AvbKernelCmdlineDescriptor| and then
173 * performing proper substitution of the variables
174 * $(ANDROID_SYSTEM_PARTUUID), $(ANDROID_BOOT_PARTUUID), and
175 * $(ANDROID_VBMETA_PARTUUID) using the
176 * get_unique_guid_for_partition() operation in |AvbOps|. Additionally
177 * $(ANDROID_VERITY_MODE) will be replaced with the proper dm-verity
178 * option depending on the value of |hashtree_error_mode|.
180 * Additionally, the |cmdline| field will have the following kernel
181 * command-line options set (unless verification is disabled, see
184 * androidboot.veritymode: This is set to 'disabled' if the
185 * AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED flag is set in top-level
186 * vbmeta struct. Otherwise it is set to 'enforcing' if the
187 * passed-in hashtree error mode is AVB_HASHTREE_ERROR_MODE_RESTART
188 * or AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE, 'eio' if it's
189 * set to AVB_HASHTREE_ERROR_MODE_EIO, and 'logging' if it's set to
190 * AVB_HASHTREE_ERROR_MODE_LOGGING.
192 * androidboot.vbmeta.invalidate_on_error: This is set to 'yes' only
193 * if hashtree validation isn't disabled and the passed-in hashtree
194 * error mode is AVB_HASHTREE_ERROR_MODE_RESTART_AND_INVALIDATE.
196 * androidboot.vbmeta.device_state: set to "locked" or "unlocked"
197 * depending on the result of the result of AvbOps's
198 * read_is_unlocked() function.
200 * androidboot.vbmeta.{hash_alg, size, digest}: Will be set to
201 * the digest of all images in |vbmeta_images|.
203 * androidboot.vbmeta.device: This is set to the value
204 * PARTUUID=$(ANDROID_VBMETA_PARTUUID) before substitution so it
205 * will end up pointing to the vbmeta partition for the verified
206 * slot. If there is no vbmeta partition it will point to the boot
207 * partition of the verified slot.
209 * androidboot.vbmeta.avb_version: This is set to the decimal value
210 * of AVB_VERSION_MAJOR followed by a dot followed by the decimal
211 * value of AVB_VERSION_MINOR, for example "1.0" or "1.4". This
212 * version number represents the vbmeta file format version
213 * supported by libavb copy used in the boot loader. This is not
214 * necessarily the same version number of the on-disk metadata for
215 * the slot that was verified.
217 * Note that androidboot.slot_suffix is not set in the |cmdline| field
218 * in |AvbSlotVerifyData| - you will have to set this yourself.
220 * If the |AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED| flag is set
221 * in the top-level vbmeta struct then only the top-level vbmeta
222 * struct is verified and descriptors will not processed. The return
223 * value will be set accordingly (if this flag is set via 'avbctl
224 * disable-verification' then the return value will be
225 * |AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION|) and
226 * |AvbSlotVerifyData| is returned. Additionally all partitions in the
227 * |requested_partitions| are loaded and the |cmdline| field is set to
228 * "root=PARTUUID=$(ANDROID_SYSTEM_PARTUUID)" and the GUID for the
229 * appropriate system partition is substituted in. Note that none of
230 * the androidboot.* options mentioned above will be set.
232 * This struct may grow in the future without it being considered an
237 AvbVBMetaData* vbmeta_images;
238 size_t num_vbmeta_images;
239 AvbPartitionData* loaded_partitions;
240 size_t num_loaded_partitions;
242 uint64_t rollback_indexes[AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS];
245 /* Calculates a digest of all vbmeta images in |data| using
246 * the digest indicated by |digest_type|. Stores the result
247 * in |out_digest| which must be large enough to hold a digest
248 * of the requested type.
250 void avb_slot_verify_data_calculate_vbmeta_digest(AvbSlotVerifyData* data,
251 AvbDigestType digest_type,
252 uint8_t* out_digest);
254 /* Frees a |AvbSlotVerifyData| including all data it points to. */
255 void avb_slot_verify_data_free(AvbSlotVerifyData* data);
257 /* Performs a full verification of the slot identified by |ab_suffix|
258 * and load and verify the contents of the partitions whose name is in
259 * the NULL-terminated string array |requested_partitions| (each
260 * partition must use hash verification). If not using A/B, pass an
261 * empty string (e.g. "", not NULL) for |ab_suffix|. This parameter
262 * must include the leading underscore, for example "_a" should be
263 * used to refer to the first slot.
265 * Typically the |requested_partitions| array only contains a single
266 * item for the boot partition, 'boot'.
268 * Verification includes loading and verifying data from the 'vbmeta',
269 * the requested hash partitions, and possibly other partitions (with
270 * |ab_suffix| appended), inspecting rollback indexes, and checking if
271 * the public key used to sign the data is acceptable. The functions
272 * in |ops| will be used to do this.
274 * If |out_data| is not NULL, it will be set to a newly allocated
275 * |AvbSlotVerifyData| struct containing all the data needed to
276 * actually boot the slot. This data structure should be freed with
277 * avb_slot_verify_data_free() when you are done with it. See below
278 * for when this is returned.
280 * The |flags| parameter is used to influence the semantics of
281 * avb_slot_verify() - for example the
282 * AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR flag can be used to
283 * ignore verification errors which is something needed in the
284 * UNLOCKED state. See the AvbSlotVerifyFlags enumeration for details.
286 * The |hashtree_error_mode| parameter should be set to the desired
287 * error handling mode when hashtree validation fails inside the
288 * HLOS. This value isn't used by libavb per se - it is forwarded to
289 * the HLOS through the androidboot.veritymode and
290 * androidboot.vbmeta.invalidate_on_error cmdline parameters. See the
291 * AvbHashtreeErrorMode enumeration for details.
293 * Also note that |out_data| is never set if
294 * AVB_SLOT_VERIFY_RESULT_ERROR_OOM, AVB_SLOT_VERIFY_RESULT_ERROR_IO,
295 * or AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned.
297 * AVB_SLOT_VERIFY_RESULT_OK is returned if everything is verified
298 * correctly and all public keys are accepted.
300 * AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED is returned if
301 * everything is verified correctly out but one or more public keys
302 * are not accepted. This includes the case where integrity data is
305 * AVB_SLOT_VERIFY_RESULT_ERROR_OOM is returned if unable to
308 * AVB_SLOT_VERIFY_RESULT_ERROR_IO is returned if an I/O error
309 * occurred while trying to load data or get a rollback index.
311 * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION is returned if the data
312 * did not verify, e.g. the digest didn't match or signature checks
315 * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned if a
316 * rollback index was less than its stored value.
318 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned if some
319 * of the metadata is invalid or inconsistent.
321 * AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION is returned if
322 * some of the metadata requires a newer version of libavb than what
325 * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_ARGUMENT is returned if the
326 * caller passed invalid parameters, for example trying to use
327 * AVB_HASHTREE_ERROR_MODE_LOGGING without
328 * AVB_SLOT_VERIFY_FLAGS_ALLOW_VERIFICATION_ERROR.
330 AvbSlotVerifyResult avb_slot_verify(AvbOps* ops,
331 const char* const* requested_partitions,
332 const char* ab_suffix,
333 AvbSlotVerifyFlags flags,
334 AvbHashtreeErrorMode hashtree_error_mode,
335 AvbSlotVerifyData** out_data);
341 #endif /* AVB_SLOT_VERIFY_H_ */