async def test_sflash():
dis.clear()
dis.text(None, 18, 'Serial Flash')
dis.show()
from sflash import SF
from ustruct import pack
import ngu
msize = 1024 * 1024
SF.chip_erase()
for phase in [0, 1]:
steps = 7 * 4
for i in range(steps):
dis.progress_bar(i / steps)
dis.show()
await sleep_ms(250)
if not SF.is_busy(): break
assert not SF.is_busy() # "didn't finish"
# leave chip blank
if phase == 1: break
buf = bytearray(32)
for addr in range(0, msize, 1024):
SF.read(addr, buf)
assert set(buf) == {255} # "not blank"
rnd = ngu.hash.sha256s(pack('I', addr))
SF.write(addr, rnd)
SF.read(addr, buf)
assert buf == rnd # "write failed"
dis.progress_bar_show(addr / msize)
# check no aliasing, also right size part
for addr in range(0, msize, 1024):
expect = ngu.hash.sha256s(pack('I', addr))
SF.read(addr, buf)
assert buf == expect # "readback failed"
dis.progress_bar_show(addr / msize)
async def interact(self):
from version import decode_firmware_header
from sflash import SF
date, version, _ = decode_firmware_header(self.hdr)
msg = '''\
Install this new firmware?
{version}
{built}
Binary checksum and signature will be further verified before any changes are made.
'''.format(version=version, built=date)
try:
ch = await ux_show_story(msg)
if ch == 'y':
# Accepted:
# - write final file header, so bootloader will see it
# - reboot to start process
from glob import dis
import callgate
SF.write(self.length, self.hdr)
dis.fullscreen('Upgrading...', percent=1)
callgate.show_logout(2)
else:
# they don't want to!
self.refused = True
SF.block_erase(0) # just in case, but not required
await ux_dramatic_pause("Refused.", 2)
except BaseException as exc:
self.failed = "Exception"
sys.print_exception(exc)
finally:
UserAuthorizedAction.cleanup() # because no results to store
self.pop_menu()
def write(self, b):
# immediate write, no buffering
assert not self.readonly
assert self.pos == self.length # "can only append"
assert self.pos + len(
b
) <= self.max_size # "past end: %r" % [self.pos, len(b), self.max_size]
left = len(b)
# must perform page-aligned (256) writes, but can start
# anywhere in the page, and can write just one byte
sofar = 0
while left:
if (self.pos + sofar) % 256 != 0:
# start is unaligned, do a partial write to align
assert sofar == 0 #, (sofar, (self.pos+sofar)) # can only happen on first page
runt = min(left, 256 - (self.pos % 256))
here = memoryview(b)[0:runt]
assert len(here) == runt
else:
# write full pages, or final runt
here = memoryview(b)[sofar:sofar + 256]
assert 1 <= len(here) <= 256
self.wait_writable()
SF.write(self.start + self.pos + sofar, here)
left -= len(here)
sofar += len(here)
self.checksum.update(here)
assert left >= 0
assert sofar == len(b)
self.pos += sofar
self.length = self.pos
return sofar
def load(self, dis=None):
# Search all slots for any we can read, decrypt that,
# and pick the newest one (in unlikely case of dups)
# reset
self.current.clear()
self.overrides.clear()
self.my_pos = 0
self.is_dirty = 0
self.capacity = 0
# 4k, but last 32 bytes are a SHA (itself encrypted)
global _tmp
buf = bytearray(4)
empty = 0
for pos in SLOTS:
if dis:
dis.progress_bar_show(
(pos - SLOTS.start) / (SLOTS.stop - SLOTS.start))
gc.collect()
SF.read(pos, buf)
if buf[0] == buf[1] == buf[2] == buf[3] == 0xff:
# erased (probably)
empty += 1
continue
# check if first 2 bytes makes sense for JSON
aes = self.get_aes(pos)
chk = aes.copy().cipher(b'{"')
if chk != buf[0:2]:
# doesn't look like JSON meant for me
continue
# probably good, read it
chk = sha256()
aes = aes.cipher
expect = None
with SFFile(pos, length=4096, pre_erased=True) as fd:
for i in range(4096 / 32):
b = aes(fd.read(32))
if i != 127:
_tmp[i * 32:(i * 32) + 32] = b
chk.update(b)
else:
expect = b
try:
# verify checksum in last 32 bytes
assert expect == chk.digest()
# loads() can't work from a byte array, and converting to
# bytes here would copy it; better to use file emulation.
fd = BytesIO(_tmp)
d = ujson.load(fd)
self.capacity = fd.seek(0, 1) / 4096 # .tell() is missing
except:
# One in 65k or so chance to come here w/ garbage decoded, so
# not an error.
continue
got_age = d.get('_age', 0)
if got_age > self.current.get('_age', -1):
# likely winner
self.current = d
self.my_pos = pos
#print("NV: data @ %d w/ age=%d" % (pos, got_age))
else:
# stale data seen; clean it up.
assert self.current['_age'] > 0
#print("NV: cleanup @ %d" % pos)
SF.sector_erase(pos)
SF.wait_done()
# 4k is a large object, sigh, for us right now. cleanup
gc.collect()
# done, if we found something
if self.my_pos:
return
# nothing found.
self.my_pos = 0
self.current = self.default_values()
if empty == len(SLOTS):
# Whole thing is blank. Bad for plausible deniability. Write 3 slots
# with garbage. They will be wasted space until it fills.
blks = list(SLOTS)
shuffle(blks)
for pos in blks[0:3]:
for i in range(0, 4096, 256):
h = ngu.random.bytes(256)
SF.wait_done()
SF.write(pos + i, h)
async def handle_upload(self, offset, total_size, data):
from sflash import SF
from glob import dis, hsm_active
from utils import check_firmware_hdr
from sigheader import FW_HEADER_OFFSET, FW_HEADER_SIZE, FW_HEADER_MAGIC
# maintain a running SHA256 over what's received
if offset == 0:
self.file_checksum = sha256()
self.is_fw_upgrade = False
assert offset % 256 == 0, 'alignment'
assert offset + len(data) <= total_size <= MAX_UPLOAD_LEN, 'long'
if hsm_active:
# additional restrictions in HSM mode
assert offset + len(data) <= total_size <= MAX_TXN_LEN, 'psbt'
if offset == 0:
assert data[0:5] == b'psbt\xff', 'psbt'
for pos in range(offset, offset + len(data), 256):
if pos % 4096 == 0:
# erase here
dis.fullscreen("Receiving...", offset / total_size)
SF.sector_erase(pos)
# expect 10-22 ms delay here
await sleep_ms(12)
while SF.is_busy():
await sleep_ms(2)
# write up to 256 bytes
here = data[pos - offset:pos - offset + 256]
self.file_checksum.update(here)
# Very special case for firmware upgrades: intercept and modify
# header contents on the fly, and also fail faster if wouldn't work
# on this specific hardware.
# - workaround: ckcc-protocol upgrade process understates the file
# length and appends hdr, but that's kinda a bug, so support both
is_trailer = (pos == (total_size - FW_HEADER_SIZE)
or pos == total_size)
if pos == (FW_HEADER_OFFSET & ~255):
hdr = memoryview(here)[-128:]
magic, = unpack_from('<I', hdr[0:4])
if magic == FW_HEADER_MAGIC:
self.is_fw_upgrade = bytes(hdr)
prob = check_firmware_hdr(hdr, total_size)
if prob:
raise ValueError(prob)
if is_trailer and self.is_fw_upgrade:
# expect the trailer to exactly match the original one
assert len(here) == 128 # == FW_HEADER_SIZE
hdr = memoryview(here)[-128:]
assert hdr == self.is_fw_upgrade # indicates hacking
# but don't write it, instead offer user a chance to abort
from auth import authorize_upgrade
authorize_upgrade(self.is_fw_upgrade, pos)
# pretend we wrote it, so ckcc-protocol or whatever gives normal feedback
return offset
SF.write(pos, here)
# full page write: 0.6 to 3ms
while SF.is_busy():
await sleep_ms(1)
if offset + len(data) >= total_size and not hsm_active:
# probably done
dis.progress_bar_show(1.0)
ux.restore_menu()
return offset
settings.save()
b = bytearray(4096)
SF.read(settings.my_pos, b)
was_age = settings.get('_age')
settings.set('wrecked', 123)
settings.save()
assert settings.get('_age') == was_age+1
was_pos = settings.my_pos
# write old data everywhere else
for pos in SLOTS:
if pos != was_pos:
for i in range(0, 4096, 256):
SF.write(pos+i, b[i:i+256])
settings.load()
assert was_pos == settings.my_pos
assert settings.get('_age') == was_age+1
assert settings.get('wrecked') == 123
# try changing one byte
b = bytearray(256)
SF.read(settings.my_pos, b)
for i in range(10, 100):
# can only change non-zero bytes (ie. clear bits)
if b[i] != 0:
b[i] = 0
break
SF.write(settings.my_pos, b)
async def handle_upload(self, offset, total_size, data):
from sflash import SF
from glob import dis, hsm_active
from utils import check_firmware_hdr
from sigheader import FW_HEADER_OFFSET, FW_HEADER_SIZE
# maintain a running SHA256 over what's received
if offset == 0:
self.file_checksum = sha256()
assert offset % 256 == 0, 'alignment'
assert offset + len(data) <= total_size <= MAX_UPLOAD_LEN, 'long'
if hsm_active:
# additional restrictions in HSM mode
assert offset + len(data) <= total_size <= MAX_TXN_LEN, 'psbt'
if offset == 0:
assert data[0:5] == b'psbt\xff', 'psbt'
for pos in range(offset, offset + len(data), 256):
if pos % 4096 == 0:
# erase here
dis.fullscreen("Receiving...", offset / total_size)
SF.sector_erase(pos)
# expect 10-22 ms delay here
await sleep_ms(12)
while SF.is_busy():
await sleep_ms(2)
# write up to 256 bytes
here = data[pos - offset:pos - offset + 256]
self.file_checksum.update(here)
# Very special case for firmware upgrades: intercept and modify
# header contents on the fly, and also fail faster if wouldn't work
# on this specific hardware.
# - workaround: ckcc-protocol upgrade process understates the file
# length and appends hdr, but that's kinda a bug, so support both
if (pos == (FW_HEADER_OFFSET & ~255)
or pos == (total_size - FW_HEADER_SIZE)
or pos == total_size):
prob = check_firmware_hdr(memoryview(here)[-128:],
None,
bad_magic_ok=True)
if prob:
raise ValueError(prob)
SF.write(pos, here)
# full page write: 0.6 to 3ms
while SF.is_busy():
await sleep_ms(1)
if offset + len(data) >= total_size and not hsm_active:
# probably done
dis.progress_bar_show(1.0)
ux.restore_menu()
return offset
