""" Class for standard NVS page structure """
+
+
class Page(object):
PAGE_PARAMS = {
"max_size": 4096,
CHUNK_ANY = 0xFF
ACTIVE = 0xFFFFFFFE
FULL = 0xFFFFFFFC
- VERSION1=0xFF
- VERSION2=0xFE
+ VERSION1 = 0xFF
+ VERSION2 = 0xFE
def __init__(self, page_num, is_rsrv_page=False):
self.entry_num = 0
self.encr_key = None
self.bitmap_array = array.array('B')
self.version = Page.VERSION2
- self.page_buf = bytearray(b'\xff')*Page.PAGE_PARAMS["max_size"]
+ self.page_buf = bytearray(b'\xff') * Page.PAGE_PARAMS["max_size"]
if not is_rsrv_page:
self.bitmap_array = self.create_bitmap_array()
self.set_header(page_num)
global page_header
# set page state to active
- page_header= bytearray(b'\xff') *32
+ page_header = bytearray(b'\xff') * 32
page_state_active_seq = Page.ACTIVE
struct.pack_into('<I', page_header, 0, page_state_active_seq)
# set page sequence number
struct.pack_into('<I', page_header, 28, crc & 0xFFFFFFFF)
self.page_buf[0:len(page_header)] = page_header
-
def create_bitmap_array(self):
bitarray = array.array('B')
- charsize = 32 # bitmaparray has 256 bits, hence 32 bytes
- fill = 255 # Fill all 8 bits with 1's
+ charsize = 32 # bitmaparray has 256 bits, hence 32 bytes
+ fill = 255 # Fill all 8 bits with 1's
bitarray.extend((fill,) * charsize)
return bitarray
-
def write_bitmaparray(self):
bitnum = self.entry_num * 2
- byte_idx = bitnum // 8 # Find byte index in the array
- bit_offset = bitnum & 7 # Find bit offset in given byte index
+ byte_idx = bitnum // 8 # Find byte index in the array
+ bit_offset = bitnum & 7 # Find bit offset in given byte index
mask = ~(1 << bit_offset)
self.bitmap_array[byte_idx] &= mask
start_idx = Page.BITMAPARRAY_OFFSET
end_idx = Page.BITMAPARRAY_OFFSET + Page.BITMAPARRAY_SIZE_IN_BYTES
self.page_buf[start_idx:end_idx] = self.bitmap_array
-
def encrypt_entry(self, data_arr, tweak_arr, encr_key):
# Encrypt 32 bytes of data using AES-XTS encryption
backend = default_backend()
return encrypted_data
-
def reverse_hexbytes(self, addr_tmp):
addr = []
reversed_bytes = ""
for i in range(0, len(addr_tmp), 2):
- addr.append(addr_tmp[i:i+2])
+ addr.append(addr_tmp[i:i + 2])
reversed_bytes = "".join(reversed(addr))
return reversed_bytes
-
def encrypt_data(self, data_input, no_of_entries, nvs_obj):
# Set values needed for encryption and encrypt data byte wise
encr_data_to_write = bytearray()
- data_len_needed = 64 #in hex
- tweak_len_needed = 32 #in hex
+ data_len_needed = 64 # in hex
+ tweak_len_needed = 32 # in hex
init_tweak_val = '0'
init_data_val = 'f'
tweak_tmp = ''
encr_key_input = None
-
# Extract encryption key and tweak key from given key input
if len(self.encr_key) == key_len_needed:
encr_key_input = self.encr_key
return encr_data_to_write
-
def write_entry_to_buf(self, data, entrycount,nvs_obj):
encr_data = bytearray()
self.write_bitmaparray()
self.entry_num += 1
-
def set_crc_header(self, entry_struct):
crc_data = bytearray(b'28')
crc_data[0:4] = entry_struct[0:4]
struct.pack_into('<I', entry_struct, 4, crc & 0xFFFFFFFF)
return entry_struct
-
def write_varlen_binary_data(self, entry_struct, ns_index, key, data, data_size, total_entry_count, encoding, nvs_obj):
chunk_start = 0
chunk_count = 0
# Get the size available in current page
tailroom = (Page.PAGE_PARAMS["max_entries"] - self.entry_num - 1) * Page.SINGLE_ENTRY_SIZE
- assert tailroom >=0, "Page overflow!!"
+ assert tailroom >= 0, "Page overflow!!"
# Split the binary data into two and store a chunk of available size onto curr page
if tailroom < remaining_size:
# Calculate no. of entries data chunk will require
datachunk_rounded_size = (chunk_size + 31) & ~31
datachunk_entry_count = datachunk_rounded_size // 32
- datachunk_total_entry_count = datachunk_entry_count + 1 # +1 for the entry header
+ datachunk_total_entry_count = datachunk_entry_count + 1 # +1 for the entry header
# Set Span
entry_struct[2] = datachunk_total_entry_count
entry_struct[3] = chunk_index
# Set data chunk
- data_chunk = data[offset:offset + chunk_size]
+ data_chunk = data[offset:offset + chunk_size]
# Compute CRC of data chunk
struct.pack_into('<H', entry_struct, 24, chunk_size)
offset = offset + chunk_size
-
# All chunks are stored, now store the index
if not remaining_size:
# Initialise data field to 0xff
- data_array = bytearray(b'\xff')*8
+ data_array = bytearray(b'\xff') * 8
entry_struct[24:32] = data_array
# change type of data to BLOB_IDX
return entry_struct
-
def write_single_page_entry(self, entry_struct, data, datalen, data_entry_count, nvs_obj):
# compute CRC of data
struct.pack_into('<H', entry_struct, 24, datalen)
# write actual data
self.write_entry_to_buf(data, data_entry_count, nvs_obj)
-
"""
Low-level function to write variable length data into page buffer. Data should be formatted
according to encoding specified.
# Set size of data
datalen = len(data)
- if version == Page.VERSION1:
- if datalen > Page.PAGE_PARAMS["max_old_blob_size"]:
+ if datalen > Page.PAGE_PARAMS["max_old_blob_size"]:
+ if version == Page.VERSION1:
raise InputError("Version %s\n%s: Size exceeds max allowed length." % (VERSION1_PRINT,key))
-
- if version == Page.VERSION2:
- if encoding == "string":
- if datalen > Page.PAGE_PARAMS["max_new_blob_size"]:
+ else:
+ if encoding == "string":
raise InputError("Version %s\n%s: Size exceeds max allowed length." % (VERSION2_PRINT,key))
# Calculate no. of entries data will require
rounded_size = (datalen + 31) & ~31
data_entry_count = rounded_size // 32
- total_entry_count = data_entry_count + 1 # +1 for the entry header
+ total_entry_count = data_entry_count + 1 # +1 for the entry header
# Check if page is already full and new page is needed to be created right away
- if encoding == "string":
- if (self.entry_num + total_entry_count) >= Page.PAGE_PARAMS["max_entries"]:
+ if self.entry_num >= Page.PAGE_PARAMS["max_entries"]:
+ raise PageFullError()
+ elif (self.entry_num + total_entry_count) >= Page.PAGE_PARAMS["max_entries"]:
+ if not (version == Page.VERSION2 and encoding in ["hex2bin", "binary", "base64"]):
raise PageFullError()
# Entry header
- entry_struct = bytearray(b'\xff')*32
+ entry_struct = bytearray(b'\xff') * 32
# Set Namespace Index
entry_struct[0] = ns_index
# Set Span
entry_struct[1] = Page.BLOB
if version == Page.VERSION2 and (encoding in ["hex2bin", "binary", "base64"]):
- entry_struct = self.write_varlen_binary_data(entry_struct,ns_index,key,data,\
- datalen,total_entry_count, encoding, nvs_obj)
+ entry_struct = self.write_varlen_binary_data(entry_struct,ns_index,key,data,
+ datalen,total_entry_count, encoding, nvs_obj)
else:
self.write_single_page_entry(entry_struct, data, datalen, data_entry_count, nvs_obj)
-
-
""" Low-level function to write data of primitive type into page buffer. """
def write_primitive_data(self, key, data, encoding, ns_index,nvs_obj):
# Check if entry exceeds max number of entries allowed per page
if self.entry_num >= Page.PAGE_PARAMS["max_entries"]:
raise PageFullError()
- entry_struct = bytearray(b'\xff')*32
- entry_struct[0] = ns_index # namespace index
- entry_struct[2] = 0x01 # Span
+ entry_struct = bytearray(b'\xff') * 32
+ entry_struct[0] = ns_index # namespace index
+ entry_struct[2] = 0x01 # Span
chunk_index = Page.CHUNK_ANY
entry_struct[3] = chunk_index
# write key
- key_array = b'\x00' *16
+ key_array = b'\x00' * 16
entry_struct[8:24] = key_array
entry_struct[8:8 + len(key)] = key.encode()
def get_data(self):
return self.page_buf
+
"""
-NVS class encapsulates all NVS specific operations to create a binary with given key-value pairs. Binary can later be flashed onto device via a flashing utility.
+NVS class encapsulates all NVS specific operations to create a binary with given key-value pairs.
+Binary can later be flashed onto device via a flashing utility.
"""
+
+
class NVS(object):
def __init__(self, fout, input_size):
self.size = input_size
return self
def __exit__(self, exc_type, exc_value, traceback):
- if exc_type == None and exc_value == None:
+ if exc_type is None and exc_value is None:
# Create pages for remaining available size
while True:
try:
- new_page = self.create_new_page()
+ self.create_new_page()
except InsufficientSizeError:
self.size = None
# Creating the last reserved page
data += page.get_data()
return data
+
class PageFullError(RuntimeError):
"""
Represents error when current page doesn't have sufficient entries left
to accommodate current request
"""
def __init__(self):
- super(PageFullError, self).__init__()
+ super(PageFullError, self).__init__()
+
class InputError(RuntimeError):
"""
def __init__(self, e):
super(InputError, self).__init__(e)
+
class InsufficientSizeError(RuntimeError):
"""
Represents error when NVS Partition size given is insufficient
def __init__(self, e):
super(InsufficientSizeError, self).__init__(e)
+
def nvs_open(result_obj, input_size):
""" Wrapper to create and NVS class object. This object can later be used to set key-value pairs
"""
return NVS(result_obj, input_size)
+
def write_entry(nvs_instance, key, datatype, encoding, value):
""" Wrapper to set key-value pair in NVS format
if datatype == "file":
abs_file_path = value
- if os.path.isabs(value) == False:
+ if os.path.isabs(value) is False:
script_dir = os.path.dirname(__file__)
abs_file_path = os.path.join(script_dir, value)
else:
nvs_instance.write_entry(key, value, encoding)
+
def nvs_close(nvs_instance):
""" Wrapper to finish writing to NVS and write data to file/stream object provided to nvs_open method
nvs_instance.__exit__(None, None, None)
-def check_input_args(input_filename=None, output_filename=None, input_part_size=None, is_key_gen=None,\
-encrypt_mode=None, key_file=None, version_no=None, print_arg_str=None, print_encrypt_arg_str=None):
+def check_input_args(input_filename=None, output_filename=None, input_part_size=None, is_key_gen=None,
+ encrypt_mode=None, key_file=None, version_no=None, print_arg_str=None, print_encrypt_arg_str=None):
global version, is_encrypt_data, input_size, key_gen
elif is_encrypt_data.lower() == 'false':
is_encrypt_data = False
-
if version == 'v1':
version = Page.VERSION1
elif version == 'v2':
elif key_gen.lower() == 'false':
key_gen = False
-
if key_gen:
if all(arg is not None for arg in [input_filename, output_filename, input_size]):
if not is_encrypt_data:
if not all(arg is not None for arg in [input_filename, output_filename]):
sys.exit(print_arg_str)
-
if is_encrypt_data and not key_gen and not key_file:
sys.exit(print_encrypt_arg_str)
# Set size
input_size = int(input_size, 0)
- if input_size % 4096 !=0:
+ if input_size % 4096 != 0:
sys.exit("Size of partition must be multiple of 4096")
# Update size as a page needs to be reserved of size 4KB
sys.exit("Minimum NVS partition size needed is 0x3000 bytes.")
-
-
def nvs_part_gen(input_filename=None, output_filename=None, input_part_size=None, is_key_gen=None, encrypt_mode=None, key_file=None, version_no=None):
""" Wrapper to generate nvs partition binary
input_file.close()
output_file.close()
-
if key_gen:
- keys_page_buf = bytearray(b'\xff')*Page.PAGE_PARAMS["max_size"]
+ keys_page_buf = bytearray(b'\xff') * Page.PAGE_PARAMS["max_size"]
key_bytes = bytearray()
if len(key_input) == key_len_needed:
key_bytes = key_input
parser = argparse.ArgumentParser(description="ESP32 NVS partition generation utility")
nvs_part_gen_group = parser.add_argument_group('To generate NVS partition')
nvs_part_gen_group.add_argument(
- "--input",
- help="Path to CSV file to parse.",
- default=None)
+ "--input",
+ help="Path to CSV file to parse.",
+ default=None)
nvs_part_gen_group.add_argument(
- "--output",
- help='Path to output converted binary file.',
- default=None)
+ "--output",
+ help='Path to output converted binary file.',
+ default=None)
nvs_part_gen_group.add_argument(
- "--size",
- help='Size of NVS Partition in bytes (must be multiple of 4096)')
+ "--size",
+ help='Size of NVS Partition in bytes (must be multiple of 4096)')
nvs_part_gen_group.add_argument(
- "--version",
- help='Set version. Default: v2',
- choices=['v1','v2'],
- default='v2',
- type=str.lower)
-
- keygen_action=nvs_part_gen_group.add_argument(
- "--keygen",
- help='Generate keys for encryption. Creates an `encryption_keys.bin` file. Default: false',
- choices=['true','false'],
- default= 'false',
- type=str.lower)
+ "--version",
+ help='Set version. Default: v2',
+ choices=['v1','v2'],
+ default='v2',
+ type=str.lower)
+
+ keygen_action = nvs_part_gen_group.add_argument(
+ "--keygen",
+ help='Generate keys for encryption. Creates an `encryption_keys.bin` file. Default: false',
+ choices=['true','false'],
+ default='false',
+ type=str.lower)
nvs_part_gen_group.add_argument(
- "--encrypt",
- help='Set encryption mode. Default: false',
- choices=['true','false'],
- default='false',
- type=str.lower)
+ "--encrypt",
+ help='Set encryption mode. Default: false',
+ choices=['true','false'],
+ default='false',
+ type=str.lower)
nvs_part_gen_group.add_argument(
- "--keyfile",
- help='File having key for encryption (Applicable only if encryption mode is true)',
- default = None)
+ "--keyfile",
+ help='File having key for encryption (Applicable only if encryption mode is true)',
+ default=None)
key_gen_group = parser.add_argument_group('To generate encryption keys')
key_gen_group._group_actions.append(keygen_action)
is_encrypt_data = args.encrypt
key_file = args.keyfile
- print_arg_str = "Invalid.\nTo generate nvs partition binary --input, --output and --size arguments are mandatory.\nTo generate encryption keys --keygen argument is mandatory."
+ print_arg_str = "Invalid.\nTo generate nvs partition binary --input, --output and --size arguments are mandatory.\n \
+ To generate encryption keys --keygen argument is mandatory."
print_encrypt_arg_str = "Missing parameter. Enter --keyfile or --keygen."
check_input_args(input_filename,output_filename, part_size, is_key_gen, is_encrypt_data, key_file, version_no, print_arg_str, print_encrypt_arg_str)
nvs_part_gen(input_filename, output_filename, part_size, is_key_gen, is_encrypt_data, key_file, version_no)
-
if __name__ == "__main__":
main()