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atjboottool: add support for FwuTail

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Change-Id: Ib01a2ff92294dd0bb59439c23f26bc31eafa4a39
This commit is contained in:
Amaury Pouly 2017-10-20 23:57:58 +02:00
parent 6e79c4cb7c
commit 7e42e90294
1 changed files with 60 additions and 6 deletions
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66
utils/atj2137/atjboottool/fwu.c
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@ -29,6 +29,11 @@
{ cprintf(RED, str_bad); return 1; } \
else { cprintf(RED, str_ok); }
#define check_field_soft(v_exp, v_have, str_ok, str_bad) \
if((v_exp) != (v_have)) \
{ cprintf(RED, str_bad); } \
else { cprintf(RED, str_ok); }
#define FWU_SIG_SIZE 16
#define FWU_BLOCK_SIZE 512
@ -47,6 +52,19 @@ const uint8_t g_fwu_signature[FWU_SIG_SIZE] =
0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x75
};
struct fwu_tail_t
{
uint8_t length; /* in blocks? it's always 1 */
uint8_t type; /* always 7 */
uint8_t reserved[14];
uint32_t fwu_checksum;
uint32_t flags; /* always 0x55aa55aa */
uint8_t desc[8]; /* always 'FwuTail' */
uint8_t fwu_crc_checksum[32]; /* always 0 */
uint8_t reserved2[444];
uint32_t fwutail_checksum;
} __attribute__((packed));
struct version_desc_t
{
uint8_t version;
@ -727,6 +745,7 @@ static int get_key_fwu_v3(size_t size, uint8_t *buf, uint8_t *blockA, uint8_t *b
uint8_t ba = buf[0x1ee] & 0xf;
uint8_t bb = buf[0x1fe] & 0xf;
cprintf(BLUE, "Crypto\n");
cprintf_field(" Block A: ", "%d\n", ba + 2);
cprintf_field(" Block B: ", "%d\n", ba + bb + 5);
@ -882,6 +901,7 @@ static int decrypt_fwu_v3(uint8_t *buf, size_t *size, uint8_t block[512], enum f
uint8_t blockA;
uint8_t blockB;
uint8_t keybuf[32];
struct fwu_hdr_t *hdr = (void *)buf;
memset(keybuf, 0, sizeof(keybuf));
int ret = get_key_fwu_v3(*size, buf, &blockA, &blockB, keybuf, block);
if(ret != 0)
@ -890,6 +910,7 @@ static int decrypt_fwu_v3(uint8_t *buf, size_t *size, uint8_t block[512], enum f
size_t file_size = *size;
/* the input buffer is reorganized based on two offsets (blockA and blockB),
* skip 2048 bytes of data used for crypto init */
*size = hdr->fw_size; /* use firmware size, not file size */
*size -= 2048;
uint8_t *tmpbuf = malloc(*size);
memset(tmpbuf, 0, *size);
@ -919,12 +940,7 @@ static int decrypt_fwu_v3(uint8_t *buf, size_t *size, uint8_t block[512], enum f
rounds_to_perform = 1;
/* the ATJ213x and ATJ2127 do not use the same encryption at this point, and I
* don't see any obvious way to tell which encryption is used (since they
* use the same version above). The only difference is that ATJ2127 images
* I have seen have an extra 512 bytes at the end file (ie the actual file
* is 512 bytes larger than indicated by the header) but I don't know if this
* is the case for all files. Thus, unless the user force encryption mode,
* try both and see if one looks like an AFI file. To guess which one to use,
* decrypt the first sector and see if it looks like an AFI file */
* use the same version above). */
bool is_atj2127 = false;
if(mode == FWU_AUTO)
{
@ -951,6 +967,17 @@ static int decrypt_fwu_v3(uint8_t *buf, size_t *size, uint8_t block[512], enum f
return 0;
}
uint32_t fwu_checksum(void *buf, size_t size)
{
if(size % 4)
cprintf(GREY, "WARNING: checksum of buffer whose length is not a multiple of 4");
uint32_t *p = buf;
uint32_t sum = 0;
for(size_t i = 0; i < size / 4; i++)
sum += *p++;
return sum;
}
int fwu_decrypt(uint8_t *buf, size_t *size, enum fwu_mode_t mode)
{
struct fwu_hdr_t *hdr = (void *)buf;
@ -1010,6 +1037,33 @@ int fwu_decrypt(uint8_t *buf, size_t *size, enum fwu_mode_t mode)
return 2;
}
/* check whether the firmware has a FwuTail (as far as I know, there is no flag anywhere that
* indicates its presence or not) */
struct fwu_tail_t *tail = (void *)(buf + hdr->fw_size - sizeof(struct fwu_tail_t));
if(tail->flags == 0x55aa55aa && strcmp((char *)tail->desc, "FwuTail") == 0)
{
cprintf(BLUE, "Tail\n");
cprintf_field(" Length: ", "%d ", tail->length);
check_field_soft(tail->length, 1, "Ok\n", "Fail\n");
cprintf_field(" Type: ", "%d ", tail->type);
check_field_soft(tail->type, 7, "Ok\n", "Fail\n");
cprintf_field(" FW checksum: ", "%x ", tail->fwu_checksum);
check_field_soft(fwu_checksum(buf, hdr->fw_size - sizeof(struct fwu_tail_t)),
tail->fwu_checksum, "Ok\n", "Mismatch\n");
cprintf(GREEN, " FW CRC Checksum: ");
for(unsigned i = 0; i < sizeof(tail->fwu_crc_checksum); i++)
cprintf(YELLOW, "%02x", tail->fwu_crc_checksum[i]);
cprintf(RED, " Ignored (should be 0)\n");
cprintf_field(" Tail checksum: ", "%x ", tail->fwutail_checksum);
check_field_soft(fwu_checksum(tail, sizeof(struct fwu_tail_t) - 4),
tail->fwutail_checksum, "Ok\n", "Mismatch\n");
/* if it has a tail, the firmware size includes it, so we need to decrease it to avoid
* "decrypting" the tail and output garbage */
hdr->fw_size -= sizeof(struct fwu_tail_t);
}
else
cprintf(BLUE, "Firmware does not seem to have a tail\n");
if(g_version[ver].version == 3)
{
uint8_t block[512];