1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Permission is hereby granted, free of charge, to any person
5  * obtaining a copy of this software and associated documentation
6  * files (the "Software"), to deal in the Software without
7  * restriction, including without limitation the rights to use, copy,
8  * modify, merge, publish, distribute, sublicense, and/or sell copies
9  * of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include "avb_slot_verify.h"
26 #include "avb_chain_partition_descriptor.h"
27 #include "avb_footer.h"
28 #include "avb_hash_descriptor.h"
29 #include "avb_kernel_cmdline_descriptor.h"
30 #include "avb_sha.h"
31 #include "avb_util.h"
32 #include "avb_vbmeta_image.h"
33 #include "avb_version.h"
34 
35 /* Maximum allow length (in bytes) of a partition name, including
36  * ab_suffix.
37  */
38 #define PART_NAME_MAX_SIZE 32
39 
40 /* Maximum number of partitions that can be loaded with avb_slot_verify(). */
41 #define MAX_NUMBER_OF_LOADED_PARTITIONS 32
42 
43 /* Maximum number of vbmeta images that can be loaded with avb_slot_verify(). */
44 #define MAX_NUMBER_OF_VBMETA_IMAGES 32
45 
46 /* Maximum size of a vbmeta image - 64 KiB. */
47 #define VBMETA_MAX_SIZE (64 * 1024)
48 
49 /* Helper function to see if we should continue with verification in
50  * allow_verification_error=true mode if something goes wrong. See the
51  * comments for the avb_slot_verify() function for more information.
52  */
result_should_continue(AvbSlotVerifyResult result)53 static inline bool result_should_continue(AvbSlotVerifyResult result) {
54   switch (result) {
55     case AVB_SLOT_VERIFY_RESULT_ERROR_OOM:
56     case AVB_SLOT_VERIFY_RESULT_ERROR_IO:
57     case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA:
58     case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION:
59       return false;
60 
61     case AVB_SLOT_VERIFY_RESULT_OK:
62     case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION:
63     case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX:
64     case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED:
65       return true;
66   }
67 
68   return false;
69 }
70 
load_and_verify_hash_partition(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,bool allow_verification_error,const AvbDescriptor * descriptor,AvbSlotVerifyData * slot_data)71 static AvbSlotVerifyResult load_and_verify_hash_partition(
72     AvbOps* ops,
73     const char* const* requested_partitions,
74     const char* ab_suffix,
75     bool allow_verification_error,
76     const AvbDescriptor* descriptor,
77     AvbSlotVerifyData* slot_data) {
78   AvbHashDescriptor hash_desc;
79   const uint8_t* desc_partition_name = NULL;
80   const uint8_t* desc_salt;
81   const uint8_t* desc_digest;
82   char part_name[PART_NAME_MAX_SIZE];
83   AvbSlotVerifyResult ret;
84   AvbIOResult io_ret;
85   uint8_t* image_buf = NULL;
86   size_t part_num_read;
87   uint8_t* digest;
88   size_t digest_len;
89   const char* found;
90 
91   if (!avb_hash_descriptor_validate_and_byteswap(
92           (const AvbHashDescriptor*)descriptor, &hash_desc)) {
93     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
94     goto out;
95   }
96 
97   desc_partition_name =
98       ((const uint8_t*)descriptor) + sizeof(AvbHashDescriptor);
99   desc_salt = desc_partition_name + hash_desc.partition_name_len;
100   desc_digest = desc_salt + hash_desc.salt_len;
101 
102   if (!avb_validate_utf8(desc_partition_name, hash_desc.partition_name_len)) {
103     avb_error("Partition name is not valid UTF-8.\n");
104     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
105     goto out;
106   }
107 
108   if (!avb_str_concat(part_name,
109                       sizeof part_name,
110                       (const char*)desc_partition_name,
111                       hash_desc.partition_name_len,
112                       ab_suffix,
113                       avb_strlen(ab_suffix))) {
114     avb_error("Partition name and suffix does not fit.\n");
115     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
116     goto out;
117   }
118 
119   image_buf = avb_malloc(hash_desc.image_size);
120   if (image_buf == NULL) {
121     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
122     goto out;
123   }
124 
125   io_ret = ops->read_from_partition(ops,
126                                     part_name,
127                                     0 /* offset */,
128                                     hash_desc.image_size,
129                                     image_buf,
130                                     &part_num_read);
131   if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
132     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
133     goto out;
134   } else if (io_ret != AVB_IO_RESULT_OK) {
135     avb_errorv(part_name, ": Error loading data from partition.\n", NULL);
136     ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
137     goto out;
138   }
139   if (part_num_read != hash_desc.image_size) {
140     avb_errorv(part_name, ": Read fewer than requested bytes.\n", NULL);
141     ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
142     goto out;
143   }
144 
145   if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha256") == 0) {
146     AvbSHA256Ctx sha256_ctx;
147     avb_sha256_init(&sha256_ctx);
148     avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len);
149     avb_sha256_update(&sha256_ctx, image_buf, hash_desc.image_size);
150     digest = avb_sha256_final(&sha256_ctx);
151     digest_len = AVB_SHA256_DIGEST_SIZE;
152   } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) {
153     AvbSHA512Ctx sha512_ctx;
154     avb_sha512_init(&sha512_ctx);
155     avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len);
156     avb_sha512_update(&sha512_ctx, image_buf, hash_desc.image_size);
157     digest = avb_sha512_final(&sha512_ctx);
158     digest_len = AVB_SHA512_DIGEST_SIZE;
159   } else {
160     avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL);
161     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
162     goto out;
163   }
164 
165   if (digest_len != hash_desc.digest_len) {
166     avb_errorv(
167         part_name, ": Digest in descriptor not of expected size.\n", NULL);
168     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
169     goto out;
170   }
171 
172   if (avb_safe_memcmp(digest, desc_digest, digest_len) != 0) {
173     avb_errorv(part_name,
174                ": Hash of data does not match digest in descriptor.\n",
175                NULL);
176     ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
177     goto out;
178   }
179 
180   ret = AVB_SLOT_VERIFY_RESULT_OK;
181 
182 out:
183 
184   if (ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) {
185     /* If this is the requested partition, copy to slot_data. */
186     found = avb_strv_find_str(requested_partitions,
187                               (const char*)desc_partition_name,
188                               hash_desc.partition_name_len);
189     if (found != NULL) {
190       AvbPartitionData* loaded_partition;
191       if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) {
192         avb_errorv(part_name, ": Too many loaded partitions.\n", NULL);
193         ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
194         goto fail;
195       }
196       loaded_partition =
197           &slot_data->loaded_partitions[slot_data->num_loaded_partitions++];
198       loaded_partition->partition_name = avb_strdup(found);
199       loaded_partition->data_size = hash_desc.image_size;
200       loaded_partition->data = image_buf;
201       image_buf = NULL;
202     }
203   }
204 
205 fail:
206   if (image_buf != NULL) {
207     avb_free(image_buf);
208   }
209   return ret;
210 }
211 
load_and_verify_vbmeta(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,bool allow_verification_error,AvbVBMetaImageFlags toplevel_vbmeta_flags,int rollback_index_location,const char * partition_name,size_t partition_name_len,const uint8_t * expected_public_key,size_t expected_public_key_length,AvbSlotVerifyData * slot_data,AvbAlgorithmType * out_algorithm_type)212 static AvbSlotVerifyResult load_and_verify_vbmeta(
213     AvbOps* ops,
214     const char* const* requested_partitions,
215     const char* ab_suffix,
216     bool allow_verification_error,
217     AvbVBMetaImageFlags toplevel_vbmeta_flags,
218     int rollback_index_location,
219     const char* partition_name,
220     size_t partition_name_len,
221     const uint8_t* expected_public_key,
222     size_t expected_public_key_length,
223     AvbSlotVerifyData* slot_data,
224     AvbAlgorithmType* out_algorithm_type) {
225   char full_partition_name[PART_NAME_MAX_SIZE];
226   AvbSlotVerifyResult ret;
227   AvbIOResult io_ret;
228   size_t vbmeta_offset;
229   size_t vbmeta_size;
230   uint8_t* vbmeta_buf = NULL;
231   size_t vbmeta_num_read;
232   AvbVBMetaVerifyResult vbmeta_ret;
233   const uint8_t* pk_data;
234   size_t pk_len;
235   AvbVBMetaImageHeader vbmeta_header;
236   uint64_t stored_rollback_index;
237   const AvbDescriptor** descriptors = NULL;
238   size_t num_descriptors;
239   size_t n;
240   bool is_main_vbmeta;
241   bool is_vbmeta_partition;
242   AvbVBMetaData* vbmeta_image_data = NULL;
243 
244   ret = AVB_SLOT_VERIFY_RESULT_OK;
245 
246   avb_assert(slot_data != NULL);
247 
248   /* Since we allow top-level vbmeta in 'boot', use
249    * rollback_index_location to determine whether we're the main
250    * vbmeta struct.
251    */
252   is_main_vbmeta = (rollback_index_location == 0);
253   is_vbmeta_partition = (avb_strcmp(partition_name, "vbmeta") == 0);
254 
255   if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) {
256     avb_error("Partition name is not valid UTF-8.\n");
257     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
258     goto out;
259   }
260 
261   /* Construct full partition name. */
262   if (!avb_str_concat(full_partition_name,
263                       sizeof full_partition_name,
264                       partition_name,
265                       partition_name_len,
266                       ab_suffix,
267                       avb_strlen(ab_suffix))) {
268     avb_error("Partition name and suffix does not fit.\n");
269     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
270     goto out;
271   }
272 
273   avb_debugv("Loading vbmeta struct from partition '",
274              full_partition_name,
275              "'.\n",
276              NULL);
277 
278   /* If we're loading from the main vbmeta partition, the vbmeta
279    * struct is in the beginning. Otherwise we have to locate it via a
280    * footer.
281    */
282   if (is_vbmeta_partition) {
283     vbmeta_offset = 0;
284     vbmeta_size = VBMETA_MAX_SIZE;
285   } else {
286     uint8_t footer_buf[AVB_FOOTER_SIZE];
287     size_t footer_num_read;
288     AvbFooter footer;
289 
290     io_ret = ops->read_from_partition(ops,
291                                       full_partition_name,
292                                       -AVB_FOOTER_SIZE,
293                                       AVB_FOOTER_SIZE,
294                                       footer_buf,
295                                       &footer_num_read);
296     if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
297       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
298       goto out;
299     } else if (io_ret != AVB_IO_RESULT_OK) {
300       avb_errorv(full_partition_name, ": Error loading footer.\n", NULL);
301       ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
302       goto out;
303     }
304     avb_assert(footer_num_read == AVB_FOOTER_SIZE);
305 
306     if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf,
307                                           &footer)) {
308       avb_errorv(full_partition_name, ": Error validating footer.\n", NULL);
309       ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
310       goto out;
311     }
312 
313     /* Basic footer sanity check since the data is untrusted. */
314     if (footer.vbmeta_size > VBMETA_MAX_SIZE) {
315       avb_errorv(
316           full_partition_name, ": Invalid vbmeta size in footer.\n", NULL);
317       ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
318       goto out;
319     }
320 
321     vbmeta_offset = footer.vbmeta_offset;
322     vbmeta_size = footer.vbmeta_size;
323   }
324 
325   vbmeta_buf = avb_malloc(vbmeta_size);
326   if (vbmeta_buf == NULL) {
327     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
328     goto out;
329   }
330 
331   io_ret = ops->read_from_partition(ops,
332                                     full_partition_name,
333                                     vbmeta_offset,
334                                     vbmeta_size,
335                                     vbmeta_buf,
336                                     &vbmeta_num_read);
337   if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
338     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
339     goto out;
340   } else if (io_ret != AVB_IO_RESULT_OK) {
341     /* If we're looking for 'vbmeta' but there is no such partition,
342      * go try to get it from the boot partition instead.
343      */
344     if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION &&
345         is_vbmeta_partition) {
346       avb_debugv(full_partition_name,
347                  ": No such partition. Trying 'boot' instead.\n",
348                  NULL);
349       ret = load_and_verify_vbmeta(ops,
350                                    requested_partitions,
351                                    ab_suffix,
352                                    allow_verification_error,
353                                    0 /* toplevel_vbmeta_flags */,
354                                    0 /* rollback_index_location */,
355                                    "boot",
356                                    avb_strlen("boot"),
357                                    NULL /* expected_public_key */,
358                                    0 /* expected_public_key_length */,
359                                    slot_data,
360                                    out_algorithm_type);
361       goto out;
362     } else {
363       avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL);
364       ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
365       goto out;
366     }
367   }
368   avb_assert(vbmeta_num_read <= vbmeta_size);
369 
370   /* Check if the image is properly signed and get the public key used
371    * to sign the image.
372    */
373   vbmeta_ret =
374       avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len);
375   switch (vbmeta_ret) {
376     case AVB_VBMETA_VERIFY_RESULT_OK:
377       avb_assert(pk_data != NULL && pk_len > 0);
378       break;
379 
380     case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED:
381     case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH:
382     case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH:
383       ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION;
384       avb_errorv(full_partition_name,
385                  ": Error verifying vbmeta image: ",
386                  avb_vbmeta_verify_result_to_string(vbmeta_ret),
387                  "\n",
388                  NULL);
389       if (!allow_verification_error) {
390         goto out;
391       }
392       break;
393 
394     case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER:
395       /* No way to continue this case. */
396       ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
397       avb_errorv(full_partition_name,
398                  ": Error verifying vbmeta image: invalid vbmeta header\n",
399                  NULL);
400       goto out;
401 
402     case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION:
403       /* No way to continue this case. */
404       ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION;
405       avb_errorv(full_partition_name,
406                  ": Error verifying vbmeta image: unsupported AVB version\n",
407                  NULL);
408       goto out;
409   }
410 
411   /* Byteswap the header. */
412   avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf,
413                                              &vbmeta_header);
414 
415   /* If we're the toplevel, assign flags so they'll be passed down. */
416   if (is_main_vbmeta) {
417     toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags;
418   } else {
419     if (vbmeta_header.flags != 0) {
420       ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
421       avb_errorv(full_partition_name,
422                  ": chained vbmeta image has non-zero flags\n",
423                  NULL);
424       goto out;
425     }
426   }
427 
428   /* Check if key used to make signature matches what is expected. */
429   if (pk_data != NULL) {
430     if (expected_public_key != NULL) {
431       avb_assert(!is_main_vbmeta);
432       if (expected_public_key_length != pk_len ||
433           avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) {
434         avb_errorv(full_partition_name,
435                    ": Public key used to sign data does not match key in chain "
436                    "partition descriptor.\n",
437                    NULL);
438         ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
439         if (!allow_verification_error) {
440           goto out;
441         }
442       }
443     } else {
444       bool key_is_trusted = false;
445       const uint8_t* pk_metadata = NULL;
446       size_t pk_metadata_len = 0;
447 
448       if (vbmeta_header.public_key_metadata_size > 0) {
449         pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) +
450                       vbmeta_header.authentication_data_block_size +
451                       vbmeta_header.public_key_metadata_offset;
452         pk_metadata_len = vbmeta_header.public_key_metadata_size;
453       }
454 
455       avb_assert(is_main_vbmeta);
456       io_ret = ops->validate_vbmeta_public_key(
457           ops, pk_data, pk_len, pk_metadata, pk_metadata_len, &key_is_trusted);
458       if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
459         ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
460         goto out;
461       } else if (io_ret != AVB_IO_RESULT_OK) {
462         avb_errorv(full_partition_name,
463                    ": Error while checking public key used to sign data.\n",
464                    NULL);
465         ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
466         goto out;
467       }
468       if (!key_is_trusted) {
469         avb_errorv(full_partition_name,
470                    ": Public key used to sign data rejected.\n",
471                    NULL);
472         ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED;
473         if (!allow_verification_error) {
474           goto out;
475         }
476       }
477     }
478   }
479 
480   /* Check rollback index. */
481   io_ret = ops->read_rollback_index(
482       ops, rollback_index_location, &stored_rollback_index);
483   if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
484     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
485     goto out;
486   } else if (io_ret != AVB_IO_RESULT_OK) {
487     avb_errorv(full_partition_name,
488                ": Error getting rollback index for location.\n",
489                NULL);
490     ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
491     goto out;
492   }
493   if (vbmeta_header.rollback_index < stored_rollback_index) {
494     avb_errorv(
495         full_partition_name,
496         ": Image rollback index is less than the stored rollback index.\n",
497         NULL);
498     ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX;
499     if (!allow_verification_error) {
500       goto out;
501     }
502   }
503 
504   /* Copy vbmeta to vbmeta_images before recursing. */
505   if (is_main_vbmeta) {
506     avb_assert(slot_data->num_vbmeta_images == 0);
507   } else {
508     avb_assert(slot_data->num_vbmeta_images > 0);
509   }
510   if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) {
511     avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL);
512     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
513     goto out;
514   }
515   vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++];
516   vbmeta_image_data->partition_name = avb_strdup(partition_name);
517   vbmeta_image_data->vbmeta_data = vbmeta_buf;
518   /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long
519    * and this includes data past the end of the image. Pass the
520    * actual size of the vbmeta image. Also, no need to use
521    * avb_safe_add() since the header has already been verified.
522    */
523   vbmeta_image_data->vbmeta_size =
524       sizeof(AvbVBMetaImageHeader) +
525       vbmeta_header.authentication_data_block_size +
526       vbmeta_header.auxiliary_data_block_size;
527   vbmeta_image_data->verify_result = vbmeta_ret;
528 
529   /* Now go through all descriptors and take the appropriate action:
530    *
531    * - hash descriptor: Load data from partition, calculate hash, and
532    *   checks that it matches what's in the hash descriptor.
533    *
534    * - hashtree descriptor: Do nothing since verification happens
535    *   on-the-fly from within the OS.
536    *
537    * - chained partition descriptor: Load the footer, load the vbmeta
538    *   image, verify vbmeta image (includes rollback checks, hash
539    *   checks, bail on chained partitions).
540    */
541   descriptors =
542       avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors);
543   for (n = 0; n < num_descriptors; n++) {
544     AvbDescriptor desc;
545 
546     if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) {
547       avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL);
548       ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
549       goto out;
550     }
551 
552     switch (desc.tag) {
553       case AVB_DESCRIPTOR_TAG_HASH: {
554         AvbSlotVerifyResult sub_ret;
555         sub_ret = load_and_verify_hash_partition(ops,
556                                                  requested_partitions,
557                                                  ab_suffix,
558                                                  allow_verification_error,
559                                                  descriptors[n],
560                                                  slot_data);
561         if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
562           ret = sub_ret;
563           if (!allow_verification_error || !result_should_continue(ret)) {
564             goto out;
565           }
566         }
567       } break;
568 
569       case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: {
570         AvbSlotVerifyResult sub_ret;
571         AvbChainPartitionDescriptor chain_desc;
572         const uint8_t* chain_partition_name;
573         const uint8_t* chain_public_key;
574 
575         /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */
576         if (!is_main_vbmeta) {
577           avb_errorv(full_partition_name,
578                      ": Encountered chain descriptor not in main image.\n",
579                      NULL);
580           ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
581           goto out;
582         }
583 
584         if (!avb_chain_partition_descriptor_validate_and_byteswap(
585                 (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) {
586           avb_errorv(full_partition_name,
587                      ": Chain partition descriptor is invalid.\n",
588                      NULL);
589           ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
590           goto out;
591         }
592 
593         if (chain_desc.rollback_index_location == 0) {
594           avb_errorv(full_partition_name,
595                      ": Chain partition has invalid "
596                      "rollback_index_location field.\n",
597                      NULL);
598           ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
599           goto out;
600         }
601 
602         chain_partition_name = ((const uint8_t*)descriptors[n]) +
603                                sizeof(AvbChainPartitionDescriptor);
604         chain_public_key = chain_partition_name + chain_desc.partition_name_len;
605 
606         sub_ret = load_and_verify_vbmeta(ops,
607                                          requested_partitions,
608                                          ab_suffix,
609                                          allow_verification_error,
610                                          toplevel_vbmeta_flags,
611                                          chain_desc.rollback_index_location,
612                                          (const char*)chain_partition_name,
613                                          chain_desc.partition_name_len,
614                                          chain_public_key,
615                                          chain_desc.public_key_len,
616                                          slot_data,
617                                          NULL /* out_algorithm_type */);
618         if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) {
619           ret = sub_ret;
620           if (!result_should_continue(ret)) {
621             goto out;
622           }
623         }
624       } break;
625 
626       case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: {
627         const uint8_t* kernel_cmdline;
628         AvbKernelCmdlineDescriptor kernel_cmdline_desc;
629         bool apply_cmdline;
630 
631         if (!avb_kernel_cmdline_descriptor_validate_and_byteswap(
632                 (AvbKernelCmdlineDescriptor*)descriptors[n],
633                 &kernel_cmdline_desc)) {
634           avb_errorv(full_partition_name,
635                      ": Kernel cmdline descriptor is invalid.\n",
636                      NULL);
637           ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
638           goto out;
639         }
640 
641         kernel_cmdline = ((const uint8_t*)descriptors[n]) +
642                          sizeof(AvbKernelCmdlineDescriptor);
643 
644         if (!avb_validate_utf8(kernel_cmdline,
645                                kernel_cmdline_desc.kernel_cmdline_length)) {
646           avb_errorv(full_partition_name,
647                      ": Kernel cmdline is not valid UTF-8.\n",
648                      NULL);
649           ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
650           goto out;
651         }
652 
653         /* Compare the flags for top-level VBMeta struct with flags in
654          * the command-line descriptor so command-line snippets only
655          * intended for a certain mode (dm-verity enabled/disabled)
656          * are skipped if applicable.
657          */
658         apply_cmdline = true;
659         if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) {
660           if (kernel_cmdline_desc.flags &
661               AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) {
662             apply_cmdline = false;
663           }
664         } else {
665           if (kernel_cmdline_desc.flags &
666               AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) {
667             apply_cmdline = false;
668           }
669         }
670 
671         if (apply_cmdline) {
672           if (slot_data->cmdline == NULL) {
673             slot_data->cmdline =
674                 avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1);
675             if (slot_data->cmdline == NULL) {
676               ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
677               goto out;
678             }
679             avb_memcpy(slot_data->cmdline,
680                        kernel_cmdline,
681                        kernel_cmdline_desc.kernel_cmdline_length);
682           } else {
683             /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */
684             size_t orig_size = avb_strlen(slot_data->cmdline);
685             size_t new_size =
686                 orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1;
687             char* new_cmdline = avb_calloc(new_size);
688             if (new_cmdline == NULL) {
689               ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
690               goto out;
691             }
692             avb_memcpy(new_cmdline, slot_data->cmdline, orig_size);
693             new_cmdline[orig_size] = ' ';
694             avb_memcpy(new_cmdline + orig_size + 1,
695                        kernel_cmdline,
696                        kernel_cmdline_desc.kernel_cmdline_length);
697             avb_free(slot_data->cmdline);
698             slot_data->cmdline = new_cmdline;
699           }
700         }
701       } break;
702 
703       /* Explicit fall-through */
704       case AVB_DESCRIPTOR_TAG_PROPERTY:
705       case AVB_DESCRIPTOR_TAG_HASHTREE:
706         /* Do nothing. */
707         break;
708     }
709   }
710 
711   if (rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) {
712     avb_errorv(
713         full_partition_name, ": Invalid rollback_index_location.\n", NULL);
714     ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA;
715     goto out;
716   }
717 
718   slot_data->rollback_indexes[rollback_index_location] =
719       vbmeta_header.rollback_index;
720 
721   if (out_algorithm_type != NULL) {
722     *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type;
723   }
724 
725 out:
726   /* If |vbmeta_image_data| isn't NULL it means that it adopted
727    * |vbmeta_buf| so in that case don't free it here.
728    */
729   if (vbmeta_image_data == NULL) {
730     if (vbmeta_buf != NULL) {
731       avb_free(vbmeta_buf);
732     }
733   }
734   if (descriptors != NULL) {
735     avb_free(descriptors);
736   }
737   return ret;
738 }
739 
740 #define NUM_GUIDS 3
741 
742 /* Substitutes all variables (e.g. $(ANDROID_SYSTEM_PARTUUID)) with
743  * values. Returns NULL on OOM, otherwise the cmdline with values
744  * replaced.
745  */
sub_cmdline(AvbOps * ops,const char * cmdline,const char * ab_suffix,bool using_boot_for_vbmeta)746 static char* sub_cmdline(AvbOps* ops,
747                          const char* cmdline,
748                          const char* ab_suffix,
749                          bool using_boot_for_vbmeta) {
750   const char* part_name_str[NUM_GUIDS] = {"system", "boot", "vbmeta"};
751   const char* replace_str[NUM_GUIDS] = {"$(ANDROID_SYSTEM_PARTUUID)",
752                                         "$(ANDROID_BOOT_PARTUUID)",
753                                         "$(ANDROID_VBMETA_PARTUUID)"};
754   char* ret = NULL;
755   AvbIOResult io_ret;
756 
757   /* Special-case for when the top-level vbmeta struct is in the boot
758    * partition.
759    */
760   if (using_boot_for_vbmeta) {
761     part_name_str[2] = "boot";
762   }
763 
764   /* Replace unique partition GUIDs */
765   for (size_t n = 0; n < NUM_GUIDS; n++) {
766     char part_name[PART_NAME_MAX_SIZE];
767     char guid_buf[37];
768 
769     if (!avb_str_concat(part_name,
770                         sizeof part_name,
771                         part_name_str[n],
772                         avb_strlen(part_name_str[n]),
773                         ab_suffix,
774                         avb_strlen(ab_suffix))) {
775       avb_error("Partition name and suffix does not fit.\n");
776       goto fail;
777     }
778 
779     io_ret = ops->get_unique_guid_for_partition(
780         ops, part_name, guid_buf, sizeof guid_buf);
781     if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
782       return NULL;
783     } else if (io_ret != AVB_IO_RESULT_OK) {
784       avb_error("Error getting unique GUID for partition.\n");
785       goto fail;
786     }
787 
788     if (ret == NULL) {
789       ret = avb_replace(cmdline, replace_str[n], guid_buf);
790     } else {
791       char* new_ret = avb_replace(ret, replace_str[n], guid_buf);
792       avb_free(ret);
793       ret = new_ret;
794     }
795     if (ret == NULL) {
796       goto fail;
797     }
798   }
799 
800   return ret;
801 
802 fail:
803   if (ret != NULL) {
804     avb_free(ret);
805   }
806   return NULL;
807 }
808 
cmdline_append_option(AvbSlotVerifyData * slot_data,const char * key,const char * value)809 static int cmdline_append_option(AvbSlotVerifyData* slot_data,
810                                  const char* key,
811                                  const char* value) {
812   size_t offset, key_len, value_len;
813   char* new_cmdline;
814 
815   key_len = avb_strlen(key);
816   value_len = avb_strlen(value);
817 
818   offset = 0;
819   if (slot_data->cmdline != NULL) {
820     offset = avb_strlen(slot_data->cmdline);
821     if (offset > 0) {
822       offset += 1;
823     }
824   }
825 
826   new_cmdline = avb_calloc(offset + key_len + value_len + 2);
827   if (new_cmdline == NULL) {
828     return 0;
829   }
830   if (offset > 0) {
831     avb_memcpy(new_cmdline, slot_data->cmdline, offset - 1);
832     new_cmdline[offset - 1] = ' ';
833   }
834   avb_memcpy(new_cmdline + offset, key, key_len);
835   new_cmdline[offset + key_len] = '=';
836   avb_memcpy(new_cmdline + offset + key_len + 1, value, value_len);
837   if (slot_data->cmdline != NULL) {
838     avb_free(slot_data->cmdline);
839   }
840   slot_data->cmdline = new_cmdline;
841 
842   return 1;
843 }
844 
845 #define AVB_MAX_DIGITS_UINT64 32
846 
847 /* Writes |value| to |digits| in base 10 followed by a NUL byte.
848  * Returns number of characters written excluding the NUL byte.
849  */
uint64_to_base10(uint64_t value,char digits[AVB_MAX_DIGITS_UINT64])850 static size_t uint64_to_base10(uint64_t value,
851                                char digits[AVB_MAX_DIGITS_UINT64]) {
852   char rev_digits[AVB_MAX_DIGITS_UINT64];
853   size_t n, num_digits;
854 
855   for (num_digits = 0; num_digits < AVB_MAX_DIGITS_UINT64 - 1;) {
856     rev_digits[num_digits++] = (value % 10) + '0';
857     value /= 10;
858     if (value == 0) {
859       break;
860     }
861   }
862 
863   for (n = 0; n < num_digits; n++) {
864     digits[n] = rev_digits[num_digits - 1 - n];
865   }
866   digits[n] = '\0';
867   return n;
868 }
869 
cmdline_append_version(AvbSlotVerifyData * slot_data,const char * key,uint64_t major_version,uint64_t minor_version)870 static int cmdline_append_version(AvbSlotVerifyData* slot_data,
871                                   const char* key,
872                                   uint64_t major_version,
873                                   uint64_t minor_version) {
874   char major_digits[AVB_MAX_DIGITS_UINT64];
875   char minor_digits[AVB_MAX_DIGITS_UINT64];
876   char combined[AVB_MAX_DIGITS_UINT64 * 2 + 1];
877   size_t num_major_digits, num_minor_digits;
878 
879   num_major_digits = uint64_to_base10(major_version, major_digits);
880   num_minor_digits = uint64_to_base10(minor_version, minor_digits);
881   avb_memcpy(combined, major_digits, num_major_digits);
882   combined[num_major_digits] = '.';
883   avb_memcpy(combined + num_major_digits + 1, minor_digits, num_minor_digits);
884   combined[num_major_digits + 1 + num_minor_digits] = '\0';
885 
886   return cmdline_append_option(slot_data, key, combined);
887 }
888 
cmdline_append_uint64_base10(AvbSlotVerifyData * slot_data,const char * key,uint64_t value)889 static int cmdline_append_uint64_base10(AvbSlotVerifyData* slot_data,
890                                         const char* key,
891                                         uint64_t value) {
892   char digits[AVB_MAX_DIGITS_UINT64];
893   uint64_to_base10(value, digits);
894   return cmdline_append_option(slot_data, key, digits);
895 }
896 
cmdline_append_hex(AvbSlotVerifyData * slot_data,const char * key,const uint8_t * data,size_t data_len)897 static int cmdline_append_hex(AvbSlotVerifyData* slot_data,
898                               const char* key,
899                               const uint8_t* data,
900                               size_t data_len) {
901   char hex_digits[17] = "0123456789abcdef";
902   char* hex_data;
903   int ret;
904   size_t n;
905 
906   hex_data = avb_malloc(data_len * 2 + 1);
907   if (hex_data == NULL) {
908     return 0;
909   }
910 
911   for (n = 0; n < data_len; n++) {
912     hex_data[n * 2] = hex_digits[data[n] >> 4];
913     hex_data[n * 2 + 1] = hex_digits[data[n] & 0x0f];
914   }
915   hex_data[n * 2] = '\0';
916 
917   ret = cmdline_append_option(slot_data, key, hex_data);
918   avb_free(hex_data);
919   return ret;
920 }
921 
avb_slot_verify(AvbOps * ops,const char * const * requested_partitions,const char * ab_suffix,bool allow_verification_error,AvbSlotVerifyData ** out_data)922 AvbSlotVerifyResult avb_slot_verify(AvbOps* ops,
923                                     const char* const* requested_partitions,
924                                     const char* ab_suffix,
925                                     bool allow_verification_error,
926                                     AvbSlotVerifyData** out_data) {
927   AvbSlotVerifyResult ret;
928   AvbSlotVerifyData* slot_data = NULL;
929   AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE;
930   AvbIOResult io_ret;
931   bool using_boot_for_vbmeta = false;
932 
933   if (out_data != NULL) {
934     *out_data = NULL;
935   }
936 
937   slot_data = avb_calloc(sizeof(AvbSlotVerifyData));
938   if (slot_data == NULL) {
939     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
940     goto fail;
941   }
942   slot_data->vbmeta_images =
943       avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES);
944   if (slot_data->vbmeta_images == NULL) {
945     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
946     goto fail;
947   }
948   slot_data->loaded_partitions =
949       avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS);
950   if (slot_data->loaded_partitions == NULL) {
951     ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
952     goto fail;
953   }
954 
955   ret = load_and_verify_vbmeta(ops,
956                                requested_partitions,
957                                ab_suffix,
958                                allow_verification_error,
959                                0 /* toplevel_vbmeta_flags */,
960                                0 /* rollback_index_location */,
961                                "vbmeta",
962                                avb_strlen("vbmeta"),
963                                NULL /* expected_public_key */,
964                                0 /* expected_public_key_length */,
965                                slot_data,
966                                &algorithm_type);
967   if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) {
968     goto fail;
969   }
970 
971   if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) {
972     avb_assert(avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") ==
973                0);
974     using_boot_for_vbmeta = true;
975   }
976 
977   /* If things check out, mangle the kernel command-line as needed. */
978   if (result_should_continue(ret)) {
979     /* Fill in |ab_suffix| field. */
980     slot_data->ab_suffix = avb_strdup(ab_suffix);
981     if (slot_data->ab_suffix == NULL) {
982       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
983       goto fail;
984     }
985 
986     /* Add androidboot.vbmeta.device option. */
987     if (!cmdline_append_option(slot_data,
988                                "androidboot.vbmeta.device",
989                                "PARTUUID=$(ANDROID_VBMETA_PARTUUID)")) {
990       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
991       goto fail;
992     }
993 
994     /* Add androidboot.vbmeta.avb_version option. */
995     if (!cmdline_append_version(slot_data,
996                                 "androidboot.vbmeta.avb_version",
997                                 AVB_VERSION_MAJOR,
998                                 AVB_VERSION_MINOR)) {
999       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1000       goto fail;
1001     }
1002 
1003     /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */
1004     if (slot_data->cmdline != NULL) {
1005       char* new_cmdline;
1006       new_cmdline = sub_cmdline(
1007           ops, slot_data->cmdline, ab_suffix, using_boot_for_vbmeta);
1008       if (new_cmdline == NULL) {
1009         ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1010         goto fail;
1011       }
1012       avb_free(slot_data->cmdline);
1013       slot_data->cmdline = new_cmdline;
1014     }
1015 
1016     /* Set androidboot.avb.device_state to "locked" or "unlocked". */
1017     bool is_device_unlocked;
1018     io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked);
1019     if (io_ret == AVB_IO_RESULT_ERROR_OOM) {
1020       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1021       goto fail;
1022     } else if (io_ret != AVB_IO_RESULT_OK) {
1023       avb_error("Error getting device state.\n");
1024       ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO;
1025       goto fail;
1026     }
1027     if (!cmdline_append_option(slot_data,
1028                                "androidboot.vbmeta.device_state",
1029                                is_device_unlocked ? "unlocked" : "locked")) {
1030       ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1031       goto fail;
1032     }
1033 
1034     /* Set androidboot.vbmeta.{hash_alg, size, digest} - use same hash
1035      * function as is used to sign vbmeta.
1036      */
1037     switch (algorithm_type) {
1038       /* Explicit fallthrough. */
1039       case AVB_ALGORITHM_TYPE_NONE:
1040       case AVB_ALGORITHM_TYPE_SHA256_RSA2048:
1041       case AVB_ALGORITHM_TYPE_SHA256_RSA4096:
1042       case AVB_ALGORITHM_TYPE_SHA256_RSA8192: {
1043         AvbSHA256Ctx ctx;
1044         size_t n, total_size = 0;
1045         avb_sha256_init(&ctx);
1046         for (n = 0; n < slot_data->num_vbmeta_images; n++) {
1047           avb_sha256_update(&ctx,
1048                             slot_data->vbmeta_images[n].vbmeta_data,
1049                             slot_data->vbmeta_images[n].vbmeta_size);
1050           total_size += slot_data->vbmeta_images[n].vbmeta_size;
1051         }
1052         if (!cmdline_append_option(
1053                 slot_data, "androidboot.vbmeta.hash_alg", "sha256") ||
1054             !cmdline_append_uint64_base10(
1055                 slot_data, "androidboot.vbmeta.size", total_size) ||
1056             !cmdline_append_hex(slot_data,
1057                                 "androidboot.vbmeta.digest",
1058                                 avb_sha256_final(&ctx),
1059                                 AVB_SHA256_DIGEST_SIZE)) {
1060           ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1061           goto fail;
1062         }
1063       } break;
1064       /* Explicit fallthrough. */
1065       case AVB_ALGORITHM_TYPE_SHA512_RSA2048:
1066       case AVB_ALGORITHM_TYPE_SHA512_RSA4096:
1067       case AVB_ALGORITHM_TYPE_SHA512_RSA8192: {
1068         AvbSHA512Ctx ctx;
1069         size_t n, total_size = 0;
1070         avb_sha512_init(&ctx);
1071         for (n = 0; n < slot_data->num_vbmeta_images; n++) {
1072           avb_sha512_update(&ctx,
1073                             slot_data->vbmeta_images[n].vbmeta_data,
1074                             slot_data->vbmeta_images[n].vbmeta_size);
1075           total_size += slot_data->vbmeta_images[n].vbmeta_size;
1076         }
1077         if (!cmdline_append_option(
1078                 slot_data, "androidboot.vbmeta.hash_alg", "sha512") ||
1079             !cmdline_append_uint64_base10(
1080                 slot_data, "androidboot.vbmeta.size", total_size) ||
1081             !cmdline_append_hex(slot_data,
1082                                 "androidboot.vbmeta.digest",
1083                                 avb_sha512_final(&ctx),
1084                                 AVB_SHA512_DIGEST_SIZE)) {
1085           ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM;
1086           goto fail;
1087         }
1088       } break;
1089       case _AVB_ALGORITHM_NUM_TYPES:
1090         avb_assert_not_reached();
1091         break;
1092     }
1093 
1094     if (out_data != NULL) {
1095       *out_data = slot_data;
1096     } else {
1097       avb_slot_verify_data_free(slot_data);
1098     }
1099   }
1100 
1101   if (!allow_verification_error) {
1102     avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK);
1103   }
1104 
1105   return ret;
1106 
1107 fail:
1108   if (slot_data != NULL) {
1109     avb_slot_verify_data_free(slot_data);
1110   }
1111   return ret;
1112 }
1113 
avb_slot_verify_data_free(AvbSlotVerifyData * data)1114 void avb_slot_verify_data_free(AvbSlotVerifyData* data) {
1115   if (data->ab_suffix != NULL) {
1116     avb_free(data->ab_suffix);
1117   }
1118   if (data->cmdline != NULL) {
1119     avb_free(data->cmdline);
1120   }
1121   if (data->vbmeta_images != NULL) {
1122     size_t n;
1123     for (n = 0; n < data->num_vbmeta_images; n++) {
1124       AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n];
1125       if (vbmeta_image->partition_name != NULL) {
1126         avb_free(vbmeta_image->partition_name);
1127       }
1128       if (vbmeta_image->vbmeta_data != NULL) {
1129         avb_free(vbmeta_image->vbmeta_data);
1130       }
1131     }
1132     avb_free(data->vbmeta_images);
1133   }
1134   if (data->loaded_partitions != NULL) {
1135     size_t n;
1136     for (n = 0; n < data->num_loaded_partitions; n++) {
1137       AvbPartitionData* loaded_partition = &data->loaded_partitions[n];
1138       if (loaded_partition->partition_name != NULL) {
1139         avb_free(loaded_partition->partition_name);
1140       }
1141       if (loaded_partition->data != NULL) {
1142         avb_free(loaded_partition->data);
1143       }
1144     }
1145     avb_free(data->loaded_partitions);
1146   }
1147   avb_free(data);
1148 }
1149 
avb_slot_verify_result_to_string(AvbSlotVerifyResult result)1150 const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) {
1151   const char* ret = NULL;
1152 
1153   switch (result) {
1154     case AVB_SLOT_VERIFY_RESULT_OK:
1155       ret = "OK";
1156       break;
1157     case AVB_SLOT_VERIFY_RESULT_ERROR_OOM:
1158       ret = "ERROR_OOM";
1159       break;
1160     case AVB_SLOT_VERIFY_RESULT_ERROR_IO:
1161       ret = "ERROR_IO";
1162       break;
1163     case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION:
1164       ret = "ERROR_VERIFICATION";
1165       break;
1166     case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX:
1167       ret = "ERROR_ROLLBACK_INDEX";
1168       break;
1169     case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED:
1170       ret = "ERROR_PUBLIC_KEY_REJECTED";
1171       break;
1172     case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA:
1173       ret = "ERROR_INVALID_METADATA";
1174       break;
1175     case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION:
1176       ret = "ERROR_UNSUPPORTED_VERSION";
1177       break;
1178       /* Do not add a 'default:' case here because of -Wswitch. */
1179   }
1180 
1181   if (ret == NULL) {
1182     avb_error("Unknown AvbSlotVerifyResult value.\n");
1183     ret = "(unknown)";
1184   }
1185 
1186   return ret;
1187 }
1188