Package: prim_cipher_pkg

File: prim_cipher_pkg.sv

Description

Copyright lowRISC contributors.
Licensed under the Apache License, Version 2.0, see LICENSE for details.
SPDX-License-Identifier: Apache-2.0

This package holds common constants and functions for PRESENT- and
PRINCE-based scrambling devices.

Signals

Name	Type	Description
prim_cipher_pkg	endpackage

Constants

Name	Type	Value	Description
PRINCE_SBOX4	logic [15:0][3:0]	{ 4'h4, 4'hD, 4'h5, 4'hE,
PRINCE_SBOX4_INV	logic [15:0][3:0]	{ 4'h1, 4'hC, 4'hE, 4'h5,
PRINCE_SHIFT_ROWS64	logic [15:0][3:0]	undefined	nibble permutations
PRINCE_SHIFT_ROWS64_INV	logic [15:0][3:0]	logic [11:0][63:0]
PRINCE_ALPHA_CONST	logic [63:0]	64'hC0AC29B7C97C50DD	tweak constant for key modification between enc/dec modes
PRINCE_SHIFT_ROWS_CONST0	logic [15:0]	16'h7BDE	masking constants for shift rows function below
PRINCE_SHIFT_ROWS_CONST1	logic [15:0]	16'hBDE7
PRINCE_SHIFT_ROWS_CONST2	logic [15:0]	16'hDE7B
PRINCE_SHIFT_ROWS_CONST3	logic [15:0]	16'hE7BD
PRESENT_SBOX4	logic [15:0][3:0]	{ 4'h2, 4'h1, 4'h7, 4'h4,	////////////////// PRESENT Cipher // ////////////////// this is the sbox from the present cipher
PRESENT_SBOX4_INV	logic [15:0][3:0]	{ 4'hA, 4'h9, 4'h7, 4'h0,
PRESENT_PERM32	logic [31:0][4:0]	{ 5'd31, 5'd23, 5'd15, 5'd07,	these are modified permutation indices for a 32bit version that follow the same pattern as for the 64bit version
PRESENT_PERM32_INV	logic [31:0][4:0]	{ 5'd31, 5'd27, 5'd23, 5'd19,
PRESENT_PERM64	logic [63:0][5:0]	{ 6'd63, 6'd47, 6'd31, 6'd15,	these are the permutation indices of the present cipher
PRESENT_PERM64_INV	logic [63:0][5:0]	{ 6'd63, 6'd59, 6'd55, 6'd51,

Functions

prince_shiftrows_32bit (logic [31:0] state_) return (logic [31:0])

Description
nibble shifts

prince_shiftrows_64bit (logic [63:0] state_) return (logic [63:0])

prince_nibble_red16 (logic [15:0]) return (logic [3:0])

Description
XOR reduction of four nibbles in a 16bit subvector

prince_mult_prime_32bit (logic [31:0] state_in) return (logic [31:0])

Description
M prime multiplication

prince_mult_prime_64bit (logic [63:0] state_in) return (logic [63:0])

Description
M prime multiplication

present_update_key64 (logic [63:0] key_in,
) return (logic [63:0])

Description
forward key schedule

present_update_key80 (logic [79:0] key_in,
) return (logic [79:0])

present_update_key128 (logic [127:0] key_in,
) return (logic [127:0])

present_inv_update_key64 (logic [63:0] key_in,
) return (logic [63:0])

Description
inverse key schedule

present_inv_update_key80 (logic [79:0] key_in,
) return (logic [79:0])

present_inv_update_key128 (logic [127:0] key_in,
) return (logic [127:0])

present_get_dec_key64 (logic [63:0] key_in,
) return (logic [63:0])

Description
these functions can be used to derive the DEC key from the ENC key by
stepping the key by the correct number of rounds using the keyschedule functions above.

present_get_dec_key80 (logic [79:0] key_in,
) return (logic [79:0])

present_get_dec_key128 (logic [127:0] key_in,
) return (logic [127:0])

sbox4_8bit (logic [7:0] state_in,
logic [15:0][3:0]) return (logic [7:0])

Description
///////////////////////
Common Subfunctions //
///////////////////////

sbox4_16bit (logic [15:0] state_in,
logic [15:0][3:0]) return (logic [15:0])

sbox4_32bit (logic [31:0] state_in,
logic [15:0][3:0]) return (logic [31:0])

sbox4_64bit (logic [63:0] state_in,
logic [15:0][3:0]) return (logic [63:0])

perm_8bit (logic [7:0] state_in,
logic [7:0][2:0]) return (logic [7:0])

perm_16bit (logic [15:0] state_in,
logic [15:0][3:0]) return (logic [15:0])

perm_32bit (logic [31:0] state_in,
logic [31:0][4:0]) return (logic [31:0])

perm_64bit (logic [63:0] state_in,
logic [63:0][5:0]) return (logic [63:0])