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avb2.0: implement AVB ops

Implement AVB ops on top of existing mmc subsystem API. Currently there
is a full implementation of such operations, defined by [1]
AVB2.0 specification:

.read_from_partition() - reads N bytes from a partition identified by
a name.
.write_to_partition() - Writes N bytes to a partition identified by a name.
.validate_vbmeta_public_key() - checks if the given public ‘vbmeta’
partition is trusted.
.get_unique_guid_for_partition() - Gets the GUID for a partition identified
by a string name.

As [1] specification recommends to use tamper-evident storage for storing
rollback indexes and device state (LOCKED/UNLOCKED),
currently are only stubs instead of full implementation for these ops:
.read_rollback_index() - Gets the rollback index for a given index location
.write_rollback_index() - Sets the rollback index to a given location
.read_is_device_unlocked() - Gets where the device is unlocked

[1] https://android.googlesource.com/platform/external/avb/+/master/README.md

Signed-off-by: Igor Opaniuk <igor.opaniuk@linaro.org>
tags/2020-06-01
Igor Opaniuk 2 years ago
committed by Tom Rini
parent
commit
3af30e4443
3 changed files with 691 additions and 0 deletions
  1. +2
    -0
      common/Makefile
  2. +610
    -0
      common/avb_verify.c
  3. +79
    -0
      include/avb_verify.h

+ 2
- 0
common/Makefile View File

@@ -120,3 +120,5 @@ obj-$(CONFIG_$(SPL_)LOG) += log.o
obj-$(CONFIG_$(SPL_)LOG_CONSOLE) += log_console.o
obj-y += s_record.o
obj-y += xyzModem.o

obj-$(CONFIG_LIBAVB) += avb_verify.o

+ 610
- 0
common/avb_verify.c View File

@@ -0,0 +1,610 @@
/*
* (C) Copyright 2018, Linaro Limited
*
* SPDX-License-Identifier: GPL-2.0+
*/

#include <avb_verify.h>
#include <fastboot.h>
#include <image.h>
#include <malloc.h>
#include <part.h>

const unsigned char avb_root_pub[1032] = {
0x0, 0x0, 0x10, 0x0, 0x55, 0xd9, 0x4, 0xad, 0xd8, 0x4,
0xaf, 0xe3, 0xd3, 0x84, 0x6c, 0x7e, 0xd, 0x89, 0x3d, 0xc2,
0x8c, 0xd3, 0x12, 0x55, 0xe9, 0x62, 0xc9, 0xf1, 0xf, 0x5e,
0xcc, 0x16, 0x72, 0xab, 0x44, 0x7c, 0x2c, 0x65, 0x4a, 0x94,
0xb5, 0x16, 0x2b, 0x0, 0xbb, 0x6, 0xef, 0x13, 0x7, 0x53,
0x4c, 0xf9, 0x64, 0xb9, 0x28, 0x7a, 0x1b, 0x84, 0x98, 0x88,
0xd8, 0x67, 0xa4, 0x23, 0xf9, 0xa7, 0x4b, 0xdc, 0x4a, 0xf,
0xf7, 0x3a, 0x18, 0xae, 0x54, 0xa8, 0x15, 0xfe, 0xb0, 0xad,
0xac, 0x35, 0xda, 0x3b, 0xad, 0x27, 0xbc, 0xaf, 0xe8, 0xd3,
0x2f, 0x37, 0x34, 0xd6, 0x51, 0x2b, 0x6c, 0x5a, 0x27, 0xd7,
0x96, 0x6, 0xaf, 0x6b, 0xb8, 0x80, 0xca, 0xfa, 0x30, 0xb4,
0xb1, 0x85, 0xb3, 0x4d, 0xaa, 0xaa, 0xc3, 0x16, 0x34, 0x1a,
0xb8, 0xe7, 0xc7, 0xfa, 0xf9, 0x9, 0x77, 0xab, 0x97, 0x93,
0xeb, 0x44, 0xae, 0xcf, 0x20, 0xbc, 0xf0, 0x80, 0x11, 0xdb,
0x23, 0xc, 0x47, 0x71, 0xb9, 0x6d, 0xd6, 0x7b, 0x60, 0x47,
0x87, 0x16, 0x56, 0x93, 0xb7, 0xc2, 0x2a, 0x9a, 0xb0, 0x4c,
0x1, 0xc, 0x30, 0xd8, 0x93, 0x87, 0xf0, 0xed, 0x6e, 0x8b,
0xbe, 0x30, 0x5b, 0xf6, 0xa6, 0xaf, 0xdd, 0x80, 0x7c, 0x45,
0x5e, 0x8f, 0x91, 0x93, 0x5e, 0x44, 0xfe, 0xb8, 0x82, 0x7,
0xee, 0x79, 0xca, 0xbf, 0x31, 0x73, 0x62, 0x58, 0xe3, 0xcd,
0xc4, 0xbc, 0xc2, 0x11, 0x1d, 0xa1, 0x4a, 0xbf, 0xfe, 0x27,
0x7d, 0xa1, 0xf6, 0x35, 0xa3, 0x5e, 0xca, 0xdc, 0x57, 0x2f,
0x3e, 0xf0, 0xc9, 0x5d, 0x86, 0x6a, 0xf8, 0xaf, 0x66, 0xa7,
0xed, 0xcd, 0xb8, 0xed, 0xa1, 0x5f, 0xba, 0x9b, 0x85, 0x1a,
0xd5, 0x9, 0xae, 0x94, 0x4e, 0x3b, 0xcf, 0xcb, 0x5c, 0xc9,
0x79, 0x80, 0xf7, 0xcc, 0xa6, 0x4a, 0xa8, 0x6a, 0xd8, 0xd3,
0x31, 0x11, 0xf9, 0xf6, 0x2, 0x63, 0x2a, 0x1a, 0x2d, 0xd1,
0x1a, 0x66, 0x1b, 0x16, 0x41, 0xbd, 0xbd, 0xf7, 0x4d, 0xc0,
0x4a, 0xe5, 0x27, 0x49, 0x5f, 0x7f, 0x58, 0xe3, 0x27, 0x2d,
0xe5, 0xc9, 0x66, 0xe, 0x52, 0x38, 0x16, 0x38, 0xfb, 0x16,
0xeb, 0x53, 0x3f, 0xe6, 0xfd, 0xe9, 0xa2, 0x5e, 0x25, 0x59,
0xd8, 0x79, 0x45, 0xff, 0x3, 0x4c, 0x26, 0xa2, 0x0, 0x5a,
0x8e, 0xc2, 0x51, 0xa1, 0x15, 0xf9, 0x7b, 0xf4, 0x5c, 0x81,
0x9b, 0x18, 0x47, 0x35, 0xd8, 0x2d, 0x5, 0xe9, 0xad, 0xf,
0x35, 0x74, 0x15, 0xa3, 0x8e, 0x8b, 0xcc, 0x27, 0xda, 0x7c,
0x5d, 0xe4, 0xfa, 0x4, 0xd3, 0x5, 0xb, 0xba, 0x3a, 0xb2,
0x49, 0x45, 0x2f, 0x47, 0xc7, 0xd, 0x41, 0x3f, 0x97, 0x80,
0x4d, 0x3f, 0xc1, 0xb5, 0xbb, 0x70, 0x5f, 0xa7, 0x37, 0xaf,
0x48, 0x22, 0x12, 0x45, 0x2e, 0xf5, 0xf, 0x87, 0x92, 0xe2,
0x84, 0x1, 0xf9, 0x12, 0xf, 0x14, 0x15, 0x24, 0xce, 0x89,
0x99, 0xee, 0xb9, 0xc4, 0x17, 0x70, 0x70, 0x15, 0xea, 0xbe,
0xc6, 0x6c, 0x1f, 0x62, 0xb3, 0xf4, 0x2d, 0x16, 0x87, 0xfb,
0x56, 0x1e, 0x45, 0xab, 0xae, 0x32, 0xe4, 0x5e, 0x91, 0xed,
0x53, 0x66, 0x5e, 0xbd, 0xed, 0xad, 0xe6, 0x12, 0x39, 0xd,
0x83, 0xc9, 0xe8, 0x6b, 0x6c, 0x2d, 0xa5, 0xee, 0xc4, 0x5a,
0x66, 0xae, 0x8c, 0x97, 0xd7, 0xd, 0x6c, 0x49, 0xc7, 0xf5,
0xc4, 0x92, 0x31, 0x8b, 0x9, 0xee, 0x33, 0xda, 0xa9, 0x37,
0xb6, 0x49, 0x18, 0xf8, 0xe, 0x60, 0x45, 0xc8, 0x33, 0x91,
0xef, 0x20, 0x57, 0x10, 0xbe, 0x78, 0x2d, 0x83, 0x26, 0xd6,
0xca, 0x61, 0xf9, 0x2f, 0xe0, 0xbf, 0x5, 0x30, 0x52, 0x5a,
0x12, 0x1c, 0x0, 0xa7, 0x5d, 0xcc, 0x7c, 0x2e, 0xc5, 0x95,
0x8b, 0xa3, 0x3b, 0xf0, 0x43, 0x2e, 0x5e, 0xdd, 0x0, 0xdb,
0xd, 0xb3, 0x37, 0x99, 0xa9, 0xcd, 0x9c, 0xb7, 0x43, 0xf7,
0x35, 0x44, 0x21, 0xc2, 0x82, 0x71, 0xab, 0x8d, 0xaa, 0xb4,
0x41, 0x11, 0xec, 0x1e, 0x8d, 0xfc, 0x14, 0x82, 0x92, 0x4e,
0x83, 0x6a, 0xa, 0x6b, 0x35, 0x5e, 0x5d, 0xe9, 0x5c, 0xcc,
0x8c, 0xde, 0x39, 0xd1, 0x4a, 0x5b, 0x5f, 0x63, 0xa9, 0x64,
0xe0, 0xa, 0xcb, 0xb, 0xb8, 0x5a, 0x7c, 0xc3, 0xb, 0xe6,
0xbe, 0xfe, 0x8b, 0xf, 0x7d, 0x34, 0x8e, 0x2, 0x66, 0x74,
0x1, 0x6c, 0xca, 0x76, 0xac, 0x7c, 0x67, 0x8, 0x2f, 0x3f,
0x1a, 0xa6, 0x2c, 0x60, 0xb3, 0xff, 0xda, 0x8d, 0xb8, 0x12,
0xc, 0x0, 0x7f, 0xcc, 0x50, 0xa1, 0x5c, 0x64, 0xa1, 0xe2,
0x5f, 0x32, 0x65, 0xc9, 0x9c, 0xbe, 0xd6, 0xa, 0x13, 0x87,
0x3c, 0x2a, 0x45, 0x47, 0xc, 0xca, 0x42, 0x82, 0xfa, 0x89,
0x65, 0xe7, 0x89, 0xb4, 0x8f, 0xf7, 0x1e, 0xe6, 0x23, 0xa5,
0xd0, 0x59, 0x37, 0x79, 0x92, 0xd7, 0xce, 0x3d, 0xfd, 0xe3,
0xa1, 0xb, 0xcf, 0x6c, 0x85, 0xa0, 0x65, 0xf3, 0x5c, 0xc6,
0x4a, 0x63, 0x5f, 0x6e, 0x3a, 0x3a, 0x2a, 0x8b, 0x6a, 0xb6,
0x2f, 0xbb, 0xf8, 0xb2, 0x4b, 0x62, 0xbc, 0x1a, 0x91, 0x25,
0x66, 0xe3, 0x69, 0xca, 0x60, 0x49, 0xb, 0xf6, 0x8a, 0xbe,
0x3e, 0x76, 0x53, 0xc2, 0x7a, 0xa8, 0x4, 0x17, 0x75, 0xf1,
0xf3, 0x3, 0x62, 0x1b, 0x85, 0xb2, 0xb0, 0xef, 0x80, 0x15,
0xb6, 0xd4, 0x4e, 0xdf, 0x71, 0xac, 0xdb, 0x2a, 0x4, 0xd4,
0xb4, 0x21, 0xba, 0x65, 0x56, 0x57, 0xe8, 0xfa, 0x84, 0xa2,
0x7d, 0x13, 0xe, 0xaf, 0xd7, 0x9a, 0x58, 0x2a, 0xa3, 0x81,
0x84, 0x8d, 0x9, 0xa0, 0x6a, 0xc1, 0xbb, 0xd9, 0xf5, 0x86,
0xac, 0xbd, 0x75, 0x61, 0x9, 0xe6, 0x8c, 0x3d, 0x77, 0xb2,
0xed, 0x30, 0x20, 0xe4, 0x0, 0x1d, 0x97, 0xe8, 0xbf, 0xc7,
0x0, 0x1b, 0x21, 0xb1, 0x16, 0xe7, 0x41, 0x67, 0x2e, 0xec,
0x38, 0xbc, 0xe5, 0x1b, 0xb4, 0x6, 0x23, 0x31, 0x71, 0x1c,
0x49, 0xcd, 0x76, 0x4a, 0x76, 0x36, 0x8d, 0xa3, 0x89, 0x8b,
0x4a, 0x7a, 0xf4, 0x87, 0xc8, 0x15, 0xf, 0x37, 0x39, 0xf6,
0x6d, 0x80, 0x19, 0xef, 0x5c, 0xa8, 0x66, 0xce, 0x1b, 0x16,
0x79, 0x21, 0xdf, 0xd7, 0x31, 0x30, 0xc4, 0x21, 0xdd, 0x34,
0x5b, 0xd2, 0x1a, 0x2b, 0x3e, 0x5d, 0xf7, 0xea, 0xca, 0x5,
0x8e, 0xb7, 0xcb, 0x49, 0x2e, 0xa0, 0xe3, 0xf4, 0xa7, 0x48,
0x19, 0x10, 0x9c, 0x4, 0xa7, 0xf4, 0x28, 0x74, 0xc8, 0x6f,
0x63, 0x20, 0x2b, 0x46, 0x24, 0x26, 0x19, 0x1d, 0xd1, 0x2c,
0x31, 0x6d, 0x5a, 0x29, 0xa2, 0x6, 0xa6, 0xb2, 0x41, 0xcc,
0xa, 0x27, 0x96, 0x9, 0x96, 0xac, 0x47, 0x65, 0x78, 0x68,
0x51, 0x98, 0xd6, 0xd8, 0xa6, 0x2d, 0xa0, 0xcf, 0xec, 0xe2,
0x74, 0xf2, 0x82, 0xe3, 0x97, 0xd9, 0x7e, 0xd4, 0xf8, 0xb,
0x70, 0x43, 0x3d, 0xb1, 0x7b, 0x97, 0x80, 0xd6, 0xcb, 0xd7,
0x19, 0xbc, 0x63, 0xb, 0xfd, 0x4d, 0x88, 0xfe, 0x67, 0xac,
0xb8, 0xcc, 0x50, 0xb7, 0x68, 0xb3, 0x5b, 0xd6, 0x1e, 0x25,
0xfc, 0x5f, 0x3c, 0x8d, 0xb1, 0x33, 0x7c, 0xb3, 0x49, 0x1,
0x3f, 0x71, 0x55, 0xe, 0x51, 0xba, 0x61, 0x26, 0xfa, 0xea,
0xe5, 0xb5, 0xe8, 0xaa, 0xcf, 0xcd, 0x96, 0x9f, 0xd6, 0xc1,
0x5f, 0x53, 0x91, 0xad, 0x5, 0xde, 0x20, 0xe7, 0x51, 0xda,
0x5b, 0x95, 0x67, 0xed, 0xf4, 0xee, 0x42, 0x65, 0x70, 0x13,
0xb, 0x70, 0x14, 0x1c, 0xc9, 0xe0, 0x19, 0xca, 0x5f, 0xf5,
0x1d, 0x70, 0x4b, 0x6c, 0x6, 0x74, 0xec, 0xb5, 0x2e, 0x77,
0xe1, 0x74, 0xa1, 0xa3, 0x99, 0xa0, 0x85, 0x9e, 0xf1, 0xac,
0xd8, 0x7e,
};

/**
* ============================================================================
* IO(mmc) auxiliary functions
* ============================================================================
*/
static unsigned long mmc_read_and_flush(struct mmc_part *part,
lbaint_t start,
lbaint_t sectors,
void *buffer)
{
unsigned long blks;
void *tmp_buf;
size_t buf_size;
bool unaligned = is_buf_unaligned(buffer);

if (start < part->info.start) {
printf("%s: partition start out of bounds\n", __func__);
return 0;
}
if ((start + sectors) > (part->info.start + part->info.size)) {
sectors = part->info.start + part->info.size - start;
printf("%s: read sector aligned to partition bounds (%ld)\n",
__func__, sectors);
}

/*
* Reading fails on unaligned buffers, so we have to
* use aligned temporary buffer and then copy to destination
*/

if (unaligned) {
printf("Handling unaligned read buffer..\n");
tmp_buf = get_sector_buf();
buf_size = get_sector_buf_size();
if (sectors > buf_size / part->info.blksz)
sectors = buf_size / part->info.blksz;
} else {
tmp_buf = buffer;
}

blks = part->mmc->block_dev.block_read(part->mmc_blk,
start, sectors, tmp_buf);
/* flush cache after read */
flush_cache((ulong)tmp_buf, sectors * part->info.blksz);

if (unaligned)
memcpy(buffer, tmp_buf, sectors * part->info.blksz);

return blks;
}

static unsigned long mmc_write(struct mmc_part *part, lbaint_t start,
lbaint_t sectors, void *buffer)
{
void *tmp_buf;
size_t buf_size;
bool unaligned = is_buf_unaligned(buffer);

if (start < part->info.start) {
printf("%s: partition start out of bounds\n", __func__);
return 0;
}
if ((start + sectors) > (part->info.start + part->info.size)) {
sectors = part->info.start + part->info.size - start;
printf("%s: sector aligned to partition bounds (%ld)\n",
__func__, sectors);
}
if (unaligned) {
tmp_buf = get_sector_buf();
buf_size = get_sector_buf_size();
printf("Handling unaligned wrire buffer..\n");
if (sectors > buf_size / part->info.blksz)
sectors = buf_size / part->info.blksz;

memcpy(tmp_buf, buffer, sectors * part->info.blksz);
} else {
tmp_buf = buffer;
}

return part->mmc->block_dev.block_write(part->mmc_blk,
start, sectors, tmp_buf);
}

static struct mmc_part *get_partition(AvbOps *ops, const char *partition)
{
int ret;
u8 dev_num;
int part_num = 0;
struct mmc_part *part;
struct blk_desc *mmc_blk;

part = malloc(sizeof(struct mmc_part));
if (!part)
return NULL;

dev_num = get_boot_device(ops);
part->mmc = find_mmc_device(dev_num);
if (!part->mmc) {
printf("No MMC device at slot %x\n", dev_num);
return NULL;
}

if (mmc_init(part->mmc)) {
printf("MMC initialization failed\n");
return NULL;
}

ret = mmc_switch_part(part->mmc, part_num);
if (ret)
return NULL;

mmc_blk = mmc_get_blk_desc(part->mmc);
if (!mmc_blk) {
printf("Error - failed to obtain block descriptor\n");
return NULL;
}

ret = part_get_info_by_name(mmc_blk, partition, &part->info);
if (!ret) {
printf("Can't find partition '%s'\n", partition);
return NULL;
}

part->dev_num = dev_num;
part->mmc_blk = mmc_blk;

return part;
}

static AvbIOResult mmc_byte_io(AvbOps *ops,
const char *partition,
s64 offset,
size_t num_bytes,
void *buffer,
size_t *out_num_read,
enum mmc_io_type io_type)
{
ulong ret;
struct mmc_part *part;
u64 start_offset, start_sector, sectors, residue;
u8 *tmp_buf;
size_t io_cnt = 0;

if (!partition || !buffer || io_type > IO_WRITE)
return AVB_IO_RESULT_ERROR_IO;

part = get_partition(ops, partition);
if (!part)
return AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION;

start_offset = calc_offset(part, offset);
while (num_bytes) {
start_sector = start_offset / part->info.blksz;
sectors = num_bytes / part->info.blksz;
/* handle non block-aligned reads */
if (start_offset % part->info.blksz ||
num_bytes < part->info.blksz) {
tmp_buf = get_sector_buf();
if (start_offset % part->info.blksz) {
residue = part->info.blksz -
(start_offset % part->info.blksz);
if (residue > num_bytes)
residue = num_bytes;
} else {
residue = num_bytes;
}

if (io_type == IO_READ) {
ret = mmc_read_and_flush(part,
part->info.start +
start_sector,
1, tmp_buf);

if (ret != 1) {
printf("%s: read error (%ld, %lld)\n",
__func__, ret, start_sector);
return AVB_IO_RESULT_ERROR_IO;
}
/*
* if this is not aligned at sector start,
* we have to adjust the tmp buffer
*/
tmp_buf += (start_offset % part->info.blksz);
memcpy(buffer, (void *)tmp_buf, residue);
} else {
ret = mmc_read_and_flush(part,
part->info.start +
start_sector,
1, tmp_buf);

if (ret != 1) {
printf("%s: read error (%ld, %lld)\n",
__func__, ret, start_sector);
return AVB_IO_RESULT_ERROR_IO;
}
memcpy((void *)tmp_buf +
start_offset % part->info.blksz,
buffer, residue);

ret = mmc_write(part, part->info.start +
start_sector, 1, tmp_buf);
if (ret != 1) {
printf("%s: write error (%ld, %lld)\n",
__func__, ret, start_sector);
return AVB_IO_RESULT_ERROR_IO;
}
}

io_cnt += residue;
buffer += residue;
start_offset += residue;
num_bytes -= residue;
continue;
}

if (sectors) {
if (io_type == IO_READ) {
ret = mmc_read_and_flush(part,
part->info.start +
start_sector,
sectors, buffer);
} else {
ret = mmc_write(part,
part->info.start +
start_sector,
sectors, buffer);
}

if (!ret) {
printf("%s: sector read error\n", __func__);
return AVB_IO_RESULT_ERROR_IO;
}

io_cnt += ret * part->info.blksz;
buffer += ret * part->info.blksz;
start_offset += ret * part->info.blksz;
num_bytes -= ret * part->info.blksz;
}
}

/* Set counter for read operation */
if (io_type == IO_READ && out_num_read)
*out_num_read = io_cnt;

return AVB_IO_RESULT_OK;
}

/**
* ============================================================================
* AVB 2.0 operations
* ============================================================================
*/

/**
* read_from_partition() - reads @num_bytes from @offset from partition
* identified by a string name
*
* @ops: contains AVB ops handlers
* @partition_name: partition name, NUL-terminated UTF-8 string
* @offset: offset from the beginning of partition
* @num_bytes: amount of bytes to read
* @buffer: destination buffer to store data
* @out_num_read:
*
* @return:
* AVB_IO_RESULT_OK, if partition was found and read operation succeed
* AVB_IO_RESULT_ERROR_IO, if i/o error occurred from the underlying i/o
* subsystem
* AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION, if there is no partition with
* the given name
*/
static AvbIOResult read_from_partition(AvbOps *ops,
const char *partition_name,
s64 offset_from_partition,
size_t num_bytes,
void *buffer,
size_t *out_num_read)
{
return mmc_byte_io(ops, partition_name, offset_from_partition,
num_bytes, buffer, out_num_read, IO_READ);
}

/**
* write_to_partition() - writes N bytes to a partition identified by a string
* name
*
* @ops: AvbOps, contains AVB ops handlers
* @partition_name: partition name
* @offset_from_partition: offset from the beginning of partition
* @num_bytes: amount of bytes to write
* @buf: data to write
* @out_num_read:
*
* @return:
* AVB_IO_RESULT_OK, if partition was found and read operation succeed
* AVB_IO_RESULT_ERROR_IO, if input/output error occurred
* AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION, if partition, specified in
* @partition_name was not found
*/
static AvbIOResult write_to_partition(AvbOps *ops,
const char *partition_name,
s64 offset_from_partition,
size_t num_bytes,
const void *buffer)
{
return mmc_byte_io(ops, partition_name, offset_from_partition,
num_bytes, (void *)buffer, NULL, IO_WRITE);
}

/**
* validate_vmbeta_public_key() - checks if the given public key used to sign
* the vbmeta partition is trusted
*
* @ops: AvbOps, contains AVB ops handlers
* @public_key_data: public key for verifying vbmeta partition signature
* @public_key_length: length of public key
* @public_key_metadata:
* @public_key_metadata_length:
* @out_key_is_trusted:
*
* @return:
* AVB_IO_RESULT_OK, if partition was found and read operation succeed
*/
static AvbIOResult validate_vbmeta_public_key(AvbOps *ops,
const u8 *public_key_data,
size_t public_key_length,
const u8
*public_key_metadata,
size_t
public_key_metadata_length,
bool *out_key_is_trusted)
{
if (!public_key_length || !public_key_data || !out_key_is_trusted)
return AVB_IO_RESULT_ERROR_IO;

*out_key_is_trusted = false;
if (public_key_length != sizeof(avb_root_pub))
return AVB_IO_RESULT_ERROR_IO;

if (memcmp(avb_root_pub, public_key_data, public_key_length) == 0)
*out_key_is_trusted = true;

return AVB_IO_RESULT_OK;
}

/**
* read_rollback_index() - gets the rollback index corresponding to the
* location of given by @out_rollback_index.
*
* @ops: contains AvbOps handlers
* @rollback_index_slot:
* @out_rollback_index: used to write a retrieved rollback index.
*
* @return
* AVB_IO_RESULT_OK, if the roolback index was retrieved
*/
static AvbIOResult read_rollback_index(AvbOps *ops,
size_t rollback_index_slot,
u64 *out_rollback_index)
{
/* For now we always return 0 as the stored rollback index. */
printf("TODO: implement %s.\n", __func__);

if (out_rollback_index)
*out_rollback_index = 0;

return AVB_IO_RESULT_OK;
}

/**
* write_rollback_index() - sets the rollback index corresponding to the
* location of given by @out_rollback_index.
*
* @ops: contains AvbOps handlers
* @rollback_index_slot:
* @rollback_index: rollback index to write.
*
* @return
* AVB_IO_RESULT_OK, if the roolback index was retrieved
*/
static AvbIOResult write_rollback_index(AvbOps *ops,
size_t rollback_index_slot,
u64 rollback_index)
{
/* For now this is a no-op. */
printf("TODO: implement %s.\n", __func__);

return AVB_IO_RESULT_OK;
}

/**
* read_is_device_unlocked() - gets whether the device is unlocked
*
* @ops: contains AVB ops handlers
* @out_is_unlocked: device unlock state is stored here, true if unlocked,
* false otherwise
*
* @return:
* AVB_IO_RESULT_OK: state is retrieved successfully
* AVB_IO_RESULT_ERROR_IO: an error occurred
*/
static AvbIOResult read_is_device_unlocked(AvbOps *ops, bool *out_is_unlocked)
{
/* For now we always return that the device is unlocked. */

printf("TODO: implement %s.\n", __func__);

*out_is_unlocked = true;

return AVB_IO_RESULT_OK;
}

/**
* get_unique_guid_for_partition() - gets the GUID for a partition identified
* by a string name
*
* @ops: contains AVB ops handlers
* @partition: partition name (NUL-terminated UTF-8 string)
* @guid_buf: buf, used to copy in GUID string. Example of value:
* 527c1c6d-6361-4593-8842-3c78fcd39219
* @guid_buf_size: @guid_buf buffer size
*
* @return:
* AVB_IO_RESULT_OK, on success (GUID found)
* AVB_IO_RESULT_ERROR_IO, if incorrect buffer size (@guid_buf_size) was
* provided
* AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION, if partition was not found
*/
static AvbIOResult get_unique_guid_for_partition(AvbOps *ops,
const char *partition,
char *guid_buf,
size_t guid_buf_size)
{
struct mmc_part *part;
size_t uuid_size;

part = get_partition(ops, partition);
if (!part)
return AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION;

uuid_size = sizeof(part->info.uuid);
if (uuid_size > guid_buf_size)
return AVB_IO_RESULT_ERROR_IO;

memcpy(guid_buf, part->info.uuid, uuid_size);
guid_buf[uuid_size - 1] = 0;

return AVB_IO_RESULT_OK;
}

/**
* ============================================================================
* AVB2.0 AvbOps alloc/initialisation/free
* ============================================================================
*/
AvbOps *avb_ops_alloc(int boot_device)
{
struct AvbOpsData *ops_data;

ops_data = avb_calloc(sizeof(struct AvbOpsData));
if (!ops_data)
return NULL;

ops_data->ops.user_data = ops_data;

ops_data->ops.read_from_partition = read_from_partition;
ops_data->ops.write_to_partition = write_to_partition;
ops_data->ops.validate_vbmeta_public_key = validate_vbmeta_public_key;
ops_data->ops.read_rollback_index = read_rollback_index;
ops_data->ops.write_rollback_index = write_rollback_index;
ops_data->ops.read_is_device_unlocked = read_is_device_unlocked;
ops_data->ops.get_unique_guid_for_partition =
get_unique_guid_for_partition;

ops_data->mmc_dev = boot_device;

return &ops_data->ops;
}

void avb_ops_free(AvbOps *ops)
{
struct AvbOpsData *ops_data;

if (ops)
return;

ops_data = ops->user_data;

if (ops_data)
avb_free(ops_data);
}

+ 79
- 0
include/avb_verify.h View File

@@ -0,0 +1,79 @@

/*
* (C) Copyright 2018, Linaro Limited
*
* SPDX-License-Identifier: GPL-2.0+
*/

#ifndef _AVB_VERIFY_H
#define _AVB_VERIFY_H

#include <../lib/libavb/libavb.h>
#include <mmc.h>

#define ALLOWED_BUF_ALIGN 8

struct AvbOpsData {
struct AvbOps ops;
int mmc_dev;
};

struct mmc_part {
int dev_num;
struct mmc *mmc;
struct blk_desc *mmc_blk;
disk_partition_t info;
};

enum mmc_io_type {
IO_READ,
IO_WRITE
};

AvbOps *avb_ops_alloc(int boot_device);
void avb_ops_free(AvbOps *ops);

/**
* ============================================================================
* I/O helper inline functions
* ============================================================================
*/
static inline uint64_t calc_offset(struct mmc_part *part, int64_t offset)
{
u64 part_size = part->info.size * part->info.blksz;

if (offset < 0)
return part_size + offset;

return offset;
}

static inline size_t get_sector_buf_size(void)
{
return (size_t)CONFIG_FASTBOOT_BUF_SIZE;
}

static inline void *get_sector_buf(void)
{
return (void *)CONFIG_FASTBOOT_BUF_ADDR;
}

static inline bool is_buf_unaligned(void *buffer)
{
return (bool)((uintptr_t)buffer % ALLOWED_BUF_ALIGN);
}

static inline int get_boot_device(AvbOps *ops)
{
struct AvbOpsData *data;

if (ops) {
data = ops->user_data;
if (data)
return data->mmc_dev;
}

return -1;
}

#endif /* _AVB_VERIFY_H */

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