def signature_subpacket_from_data(data, offset=0):
offset, length, partial = utils.new_packet_length(data, offset)
# TODO: smarter error
assert not partial
tag = data[offset]
subpacket_type = tag & 0x7F
critical = bool(tag & 0x80)
length -= 1 # Since we've parsed the tag from the data
offset += 1
sub_data = data[offset : offset + length]
offset += length
cls = SIGNATURE_SUBPACKET_TYPES.get(subpacket_type, SignatureSubpacket)
return (cls.from_subpacket_content(subpacket_type, critical, sub_data), offset)
def signature_subpacket_from_data(data, offset=0):
offset, length, partial = utils.new_packet_length(data, offset)
# TODO: smarter error
assert not partial
tag = data[offset]
subpacket_type = tag & 0x7f
critical = bool(tag & 0x80)
length -= 1 # Since we've parsed the tag from the data
offset += 1
sub_data = data[offset:offset + length]
offset += length
cls = SIGNATURE_SUBPACKET_TYPES.get(subpacket_type, SignatureSubpacket)
return (cls.from_subpacket_content(subpacket_type, critical,
sub_data), offset)
def user_attribute_subpacket_from_data(data, offset=0):
sub_data = bytearray()
offset, sub_len, sub_partial = utils.new_packet_length(data, offset)
if sub_partial:
# "An implementation MAY use Partial Body Lengths for data
# packets, be they literal, compressed, or encrypted. [...]
# Partial Body Lengths MUST NOT be used for any other packet
# types."
raise ValueError
sub_type = int(data[offset])
# + 1 for sub type
sub_data_start = offset + 1
sub_data_end = sub_data_start + sub_len - 1
sub_data.extend(data[sub_data_start:sub_data_end])
offset = sub_data_end
cls = USER_ATTRIBUTE_SUBPACKET_TYPES.get(sub_type, UserAttributeSubpacket)
return cls.from_subpacket_content(sub_type, sub_data), offset
def user_attribute_subpacket_from_data(data, offset=0):
sub_data = bytearray()
offset, sub_len, sub_partial = utils.new_packet_length(data, offset)
if sub_partial:
# "An implementation MAY use Partial Body Lengths for data
# packets, be they literal, compressed, or encrypted. [...]
# Partial Body Lengths MUST NOT be used for any other packet
# types."
raise ValueError
sub_type = int(data[offset])
# + 1 for sub type
sub_data_start = offset + 1
sub_data_end = sub_data_start + sub_len - 1
sub_data.extend(data[sub_data_start:sub_data_end])
offset = sub_data_end
cls = USER_ATTRIBUTE_SUBPACKET_TYPES.get(sub_type, UserAttributeSubpacket)
return cls.from_subpacket_content(sub_type, sub_data), offset
def parse_user_attribute_subpackets(p, parse_unknown=False):
offset = 0
while offset < len(p.data):
sub_data = bytearray()
sub_type = None
sub_offset, sub_len, sub_partial = \
utils.new_packet_length(p.data, offset)
if sub_partial:
# "An implementation MAY use Partial Body Lengths for data
# packets, be they literal, compressed, or encrypted. [...]
# Partial Body Lengths MUST NOT be used for any other packet
# types."
return
sub_type = p.data[sub_offset]
# + 1 for sub type
sub_data_start = offset + sub_offset + 1
sub_data_end = sub_data_start + sub_len
sub_data.extend(p.data[sub_data_start:sub_data_end])
offset = sub_data_end
if sub_type == 0x01:
# "The only currently defined subpacket type is 1, signifying
# an image."
# "The first two octets of the image header contain the length of
# the image header. Note that unlike other multi-octet numerical
# values in this document, due to a historical accident this
# value is encoded as a little-endian number."
header_length = sub_data[0] + (sub_data[1] << 8)
header_version = sub_data[2]
if header_version == 1:
if not header_length == 16:
continue
image_format = sub_data[3]
if any(sub_data[4:16]):
# Incorrect
continue
if (image_format == 1
or (image_format > 99 and image_format < 111)):
# "The only currently defined encoding format is the value
# 1 to indicate JPEG. Image format types 100 through 110
# are reserved for private or experimental use."
#
# "An implementation MAY try to determine the type of an
# image by examination of the image data if it is unable
# to handle a particular version of the image header or
# if a specified encoding format value is not
# recognized."
mime_type = magic.from_buffer(bytes(sub_data[16:1040]),
mime=True).decode('ascii')
yield {
'sub_type': sub_type,
'content_data': sub_data[16:],
'mimetype': mime_type,
}
elif parse_unknown:
# If we want to parse unknown, non-image data
content_data = sub_data[header_length:]
mime_type = magic.from_buffer(bytes(content_data[:1024]),
mime=True).decode('ascii')
yield {
'sub_type': sub_type,
'content_data': content_data,
'mimetype': mime_type,
}
def parse_user_attribute_subpackets(p, parse_unknown=False):
offset = 0
while offset < len(p.data):
sub_data = bytearray()
sub_type = None
sub_offset, sub_len, sub_partial = \
utils.new_packet_length(p.data, offset)
if sub_partial:
# "An implementation MAY use Partial Body Lengths for data
# packets, be they literal, compressed, or encrypted. [...]
# Partial Body Lengths MUST NOT be used for any other packet
# types."
return
sub_type = p.data[sub_offset]
# + 1 for sub type
sub_data_start = offset + sub_offset + 1
sub_data_end = sub_data_start + sub_len
sub_data.extend(p.data[sub_data_start:sub_data_end])
offset = sub_data_end
if sub_type == 0x01:
# "The only currently defined subpacket type is 1, signifying
# an image."
# "The first two octets of the image header contain the length of
# the image header. Note that unlike other multi-octet numerical
# values in this document, due to a historical accident this
# value is encoded as a little-endian number."
header_length = sub_data[0] + (sub_data[1] << 8)
header_version = sub_data[2]
if header_version == 1:
if not header_length == 16:
continue
image_format = sub_data[3]
if any(sub_data[4:16]):
# Incorrect
continue
if (image_format == 1 or
(image_format > 99 and image_format < 111)
):
# "The only currently defined encoding format is the value
# 1 to indicate JPEG. Image format types 100 through 110
# are reserved for private or experimental use."
#
# "An implementation MAY try to determine the type of an
# image by examination of the image data if it is unable
# to handle a particular version of the image header or
# if a specified encoding format value is not
# recognized."
mime_type = magic.from_buffer(bytes(sub_data[16:1040]),
mime=True).decode('ascii')
yield {
'sub_type': sub_type,
'content_data': sub_data[16:],
'mimetype': mime_type,
}
elif parse_unknown:
# If we want to parse unknown, non-image data
content_data = sub_data[header_length:]
mime_type = magic.from_buffer(bytes(content_data[:1024]),
mime=True).decode('ascii')
yield {
'sub_type': sub_type,
'content_data': content_data,
'mimetype': mime_type,
}
