DHCP Encoding Class

class bloxone.dhcp_encode

Class to assist with Hex Encoding of DHCP Options and sub_options

binary_to_hex(data)

Format hex string of binary/hex encoded data

Parameters:data (str) – data to format Returns:hex encoding as string

boolean_to_hex(flag)

Encode boolean value as single hex byte

Parameters:flag (bool/str) – True or False as bool or text Returns:hex encoding as string

empty_to_hex(data)

Return empyt hex string ‘’

Parameters:data (str) – Data not to encode (should be empty) Returns:Empty String ‘’

encode_data(sub_opt, padding=False, pad_bytes=1)

Encode the data section of a sub_option definition

Parameters:

• sub_opt (dict) – Dict containing sub option details Must include ‘data’ and ‘type’ keys
• padding (bool) – Whether extra ‘null’ termination bytes are req.
• pad_bytes (int) – Number of null bytes to append

Returns:

Hex encoded data for specified data-type as string

encode_dhcp_option(sub_opt_defs=[], padding=False, pad_bytes=1, encapsulate=False, id=None, prefix='')

Encode list of DHCP Sub Options to Hex

Parameters:

• sub_opt_defs (list) – List of Sub Option definition dictionaries
• padding (bool) – Whether extra ‘null’ termination bytes are req.
• pad_bytes (int) – Number of null bytes to append
• encapsulate (bool) – Add id and total length as prefix
• id (int) – option code to prepend
• prefix (str) – String value to prepend to encoded options

Returns:

Encoded suboption as a hex string

encode_sub_option(sub_opt, data_only=False, padding=False, pad_bytes=1)

Encode individual sub option

Parameters:

• sub_opt (dict) – Sub Option Definition, as dict.
• data_only (bool) – Encode data portion only if True (Note the sub_opt dict is also checked for the ‘data-only’ key)
• padding (bool) – Whether extra ‘null’ termination bytes are req.
• pad_bytes (int) – Number of null bytes to append

Returns:

Encoded suboption as a hex string

fqdn_to_hex(fqdn)

Encode an fdqn in RFC 1035 Section 3.1 formatted hex

Parameters:fqdn (str) – hostname to encode Returns:hex encoding as string

hex_length(hex_string)

Encode Option Length in hex (1-octet)

Parameters:hex_string (str) – Octet Encoded Hex String Returns:Number of Hex Octects as hex encoded string

int_to_hex(i, size=8)

Encode integer of specified size as signed int in hex

Parameters:

• i (int) – integer value to encode
• size (int) – size in bits [8, 16, 32]

Returns:

hex encoding as string

ip_to_hex(ip)

Encode an IPv4 or IPv6 address to hex

Parameters:ip (str) – IPv4 or IPv6 address as a string Returns:hex encoding as string

ipv4_address_to_hex(ipv4)

Encode an IPv4 address to hex

Parameters:ipv4 (str) – IPv4 address as a string Returns:hex encoding as string

ipv6_address_to_hex(ipv6)

Encode an IPv6 address to hex

Parameters:ipv6 (str) – IPv4 or IPv6 address as a string Returns:hex encoding as string

optcode_to_hex(optcode)

Encode Option Code in hex (1-octet)

Parameters:optcode (str/int) – Option Code Returns:hex encoding as string

string_to_hex(string)

Encode a text string to hex

Parameters:string (str) – text string Returns:hex encoding as string

tests()

Run through encoding methods and output example results

uint_to_hex(i, size=8)

Encode integer of specified size as unsigned int in hex Uses 2’s compliment if supplied with negative number

Parameters:

• i (int) – integer value to encode
• size (int) – size in bits [8, 16, 32]

Returns:

hex encoding as string

validate_ip(ip)

Validate input data is a valid IP address (Supports both IPv4 and IPv6)

Parameters:ip (str) – ip address as a string Returns:Return True for valid and False otherwise Return type:bool