Livt packages
Livt.Utils
Version 1.1.1
Reusable Livt utility components, including configurable CRC helpers and CRC32.
Published files (8)
src/hashing/Crc32.lvt
namespace Livt.Utils.Hashing
/**
* CRC32 checksum (IEEE 802.3 / zlib, reflected polynomial 0xEDB88320).
*
* Usage:
* 1. Reset() — initialise accumulator to 0xFFFFFFFF
* 2. ProcessBlock(blk) × 0..n — feed full 16-byte blocks
* 3. ProcessFinalBlock(blk, len) — feed last 0..16 bytes; applies final XOR
* 4. GetCrc() / GetByte(idx) — read 4-byte result, little-endian
*
* Output byte order: little-endian.
* GetByte(0) = LSB of the CRC32 value.
* GetByte(3) = MSB of the CRC32 value.
*
* Example: CRC32("123456789") = 0xCBF43926
* GetByte(0) = 0x26, GetByte(1) = 0x39, GetByte(2) = 0xF4, GetByte(3) = 0xCB
*/
component Crc32
{
// Number of bytes accepted by ProcessBlock.
public const BLOCK_SIZE: int = 16
// Little-endian running CRC accumulator; finalization applies the output XOR.
crc: byte[4]
/**
* Initialises the accumulator to 0xFFFFFFFF.
*/
new()
{
crc[0] = 0xFF
crc[1] = 0xFF
crc[2] = 0xFF
crc[3] = 0xFF
}
/**
* Initialise the accumulator to 0xFFFFFFFF, starting a new computation.
*/
public fn Reset()
{
state {
crc[0] = 0xFF
crc[1] = 0xFF
crc[2] = 0xFF
crc[3] = 0xFF
}
}
/**
* Feed a full 16-byte block into the accumulator.
* Call zero or more times before ProcessFinalBlock.
*/
public fn ProcessBlock(blk: byte[16])
{
var i: int = 0
while (i < 16) {
var b: byte = blk[i]
var idx: byte = crc[0] ^ b
var lB0: byte = this.LookupB0(idx)
var lB1: byte = this.LookupB1(idx)
var lB2: byte = this.LookupB2(idx)
var lB3: byte = this.LookupB3(idx)
state {
crc[0] = crc[1] ^ lB0
crc[1] = crc[2] ^ lB1
crc[2] = crc[3] ^ lB2
crc[3] = lB3
}
i++
}
}
/**
* Feed the last partial block and apply the final XOR.
* After this call, GetCrc() / GetByte() return the final CRC32 value.
* Pass len = 0 to finalise with no additional data (e.g. empty input).
*
* Requires: len in 0..16. Behaviour is undefined for len > 16.
*/
public fn ProcessFinalBlock(blk: byte[16], len: int)
{
var i: int = 0
while (i < len) {
var b: byte = blk[i]
var idx: byte = crc[0] ^ b
var lB0: byte = this.LookupB0(idx)
var lB1: byte = this.LookupB1(idx)
var lB2: byte = this.LookupB2(idx)
var lB3: byte = this.LookupB3(idx)
state {
crc[0] = crc[1] ^ lB0
crc[1] = crc[2] ^ lB1
crc[2] = crc[3] ^ lB2
crc[3] = lB3
}
i++
}
// Apply final XOR (0xFFFFFFFF).
var c0: byte = crc[0]
var c1: byte = crc[1]
var c2: byte = crc[2]
var c3: byte = crc[3]
state {
crc[0] = c0 ^ 0xFF
crc[1] = c1 ^ 0xFF
crc[2] = c2 ^ 0xFF
crc[3] = c3 ^ 0xFF
}
}
/**
* Return the 4-byte CRC32 result in little-endian order.
* Call only after ProcessFinalBlock.
*/
public fn GetCrc() byte[4]
{
return crc
}
/**
* Return a single byte of the CRC32 result (idx 0 = LSB, 3 = MSB).
*
* Requires: idx in 0..3. Out-of-range idx returns crc[3].
*/
public fn GetByte(idx: int) byte
{
if (idx == 0) {
return crc[0]
}
if (idx == 1) {
return crc[1]
}
if (idx == 2) {
return crc[2]
}
return crc[3]
}
/**
* Return byte 0 (LSB) of the CRC32 table entry for the given index.
*/
fn LookupB0(idx: byte) byte
{
var i: int = idx as int
if (i < 64) {
return TABLE_B0_Q0[i]
}
if (i < 128) {
var j1: int = i - 64
return TABLE_B0_Q1[j1]
}
if (i < 192) {
var j2: int = i - 128
return TABLE_B0_Q2[j2]
}
var j3: int = i - 192
return TABLE_B0_Q3[j3]
}
/**
* Return byte 1 of the CRC32 table entry for the given index.
*/
fn LookupB1(idx: byte) byte
{
var i: int = idx as int
if (i < 64) {
return TABLE_B1_Q0[i]
}
if (i < 128) {
var j1: int = i - 64
return TABLE_B1_Q1[j1]
}
if (i < 192) {
var j2: int = i - 128
return TABLE_B1_Q2[j2]
}
var j3: int = i - 192
return TABLE_B1_Q3[j3]
}
/**
* Return byte 2 of the CRC32 table entry for the given index.
*/
fn LookupB2(idx: byte) byte
{
var i: int = idx as int
if (i < 64) {
return TABLE_B2_Q0[i]
}
if (i < 128) {
var j1: int = i - 64
return TABLE_B2_Q1[j1]
}
if (i < 192) {
var j2: int = i - 128
return TABLE_B2_Q2[j2]
}
var j3: int = i - 192
return TABLE_B2_Q3[j3]
}
/**
* Return byte 3 (MSB) of the CRC32 table entry for the given index.
*/
fn LookupB3(idx: byte) byte
{
var i: int = idx as int
if (i < 64) {
return TABLE_B3_Q0[i]
}
if (i < 128) {
var j1: int = i - 64
return TABLE_B3_Q1[j1]
}
if (i < 192) {
var j2: int = i - 128
return TABLE_B3_Q2[j2]
}
var j3: int = i - 192
return TABLE_B3_Q3[j3]
}
// -----------------------------------------------------------------------
// CRC32 table — byte 0 (LSB) of each 32-bit entry.
// table[i] = CRC32 entry for byte value i; generated from polynomial 0xEDB88320.
// -----------------------------------------------------------------------
// table[ 0.. 63] & 0xFF
const TABLE_B0_Q0: byte[64] = [
0x00, 0x96, 0x2C, 0xBA, 0x19, 0x8F, 0x35, 0xA3,
0x32, 0xA4, 0x1E, 0x88, 0x2B, 0xBD, 0x07, 0x91,
0x64, 0xF2, 0x48, 0xDE, 0x7D, 0xEB, 0x51, 0xC7,
0x56, 0xC0, 0x7A, 0xEC, 0x4F, 0xD9, 0x63, 0xF5,
0xC8, 0x5E, 0xE4, 0x72, 0xD1, 0x47, 0xFD, 0x6B,
0xFA, 0x6C, 0xD6, 0x40, 0xE3, 0x75, 0xCF, 0x59,
0xAC, 0x3A, 0x80, 0x16, 0xB5, 0x23, 0x99, 0x0F,
0x9E, 0x08, 0xB2, 0x24, 0x87, 0x11, 0xAB, 0x3D]
// table[ 64..127] & 0xFF
const TABLE_B0_Q1: byte[64] = [
0x90, 0x06, 0xBC, 0x2A, 0x89, 0x1F, 0xA5, 0x33,
0xA2, 0x34, 0x8E, 0x18, 0xBB, 0x2D, 0x97, 0x01,
0xF4, 0x62, 0xD8, 0x4E, 0xED, 0x7B, 0xC1, 0x57,
0xC6, 0x50, 0xEA, 0x7C, 0xDF, 0x49, 0xF3, 0x65,
0x58, 0xCE, 0x74, 0xE2, 0x41, 0xD7, 0x6D, 0xFB,
0x6A, 0xFC, 0x46, 0xD0, 0x73, 0xE5, 0x5F, 0xC9,
0x3C, 0xAA, 0x10, 0x86, 0x25, 0xB3, 0x09, 0x9F,
0x0E, 0x98, 0x22, 0xB4, 0x17, 0x81, 0x3B, 0xAD]
// table[128..191] & 0xFF
const TABLE_B0_Q2: byte[64] = [
0x20, 0xB6, 0x0C, 0x9A, 0x39, 0xAF, 0x15, 0x83,
0x12, 0x84, 0x3E, 0xA8, 0x0B, 0x9D, 0x27, 0xB1,
0x44, 0xD2, 0x68, 0xFE, 0x5D, 0xCB, 0x71, 0xE7,
0x76, 0xE0, 0x5A, 0xCC, 0x6F, 0xF9, 0x43, 0xD5,
0xE8, 0x7E, 0xC4, 0x52, 0xF1, 0x67, 0xDD, 0x4B,
0xDA, 0x4C, 0xF6, 0x60, 0xC3, 0x55, 0xEF, 0x79,
0x8C, 0x1A, 0xA0, 0x36, 0x95, 0x03, 0xB9, 0x2F,
0xBE, 0x28, 0x92, 0x04, 0xA7, 0x31, 0x8B, 0x1D]
// table[192..255] & 0xFF
const TABLE_B0_Q3: byte[64] = [
0xB0, 0x26, 0x9C, 0x0A, 0xA9, 0x3F, 0x85, 0x13,
0x82, 0x14, 0xAE, 0x38, 0x9B, 0x0D, 0xB7, 0x21,
0xD4, 0x42, 0xF8, 0x6E, 0xCD, 0x5B, 0xE1, 0x77,
0xE6, 0x70, 0xCA, 0x5C, 0xFF, 0x69, 0xD3, 0x45,
0x78, 0xEE, 0x54, 0xC2, 0x61, 0xF7, 0x4D, 0xDB,
0x4A, 0xDC, 0x66, 0xF0, 0x53, 0xC5, 0x7F, 0xE9,
0x1C, 0x8A, 0x30, 0xA6, 0x05, 0x93, 0x29, 0xBF,
0x2E, 0xB8, 0x02, 0x94, 0x37, 0xA1, 0x1B, 0x8D]
// -----------------------------------------------------------------------
// CRC32 table — byte 1 of each 32-bit entry.
// -----------------------------------------------------------------------
// table[ 0.. 63] >> 8 & 0xFF
const TABLE_B1_Q0: byte[64] = [
0x00, 0x30, 0x61, 0x51, 0xC4, 0xF4, 0xA5, 0x95,
0x88, 0xB8, 0xE9, 0xD9, 0x4C, 0x7C, 0x2D, 0x1D,
0x10, 0x20, 0x71, 0x41, 0xD4, 0xE4, 0xB5, 0x85,
0x98, 0xA8, 0xF9, 0xC9, 0x5C, 0x6C, 0x3D, 0x0D,
0x20, 0x10, 0x41, 0x71, 0xE4, 0xD4, 0x85, 0xB5,
0xA8, 0x98, 0xC9, 0xF9, 0x6C, 0x5C, 0x0D, 0x3D,
0x30, 0x00, 0x51, 0x61, 0xF4, 0xC4, 0x95, 0xA5,
0xB8, 0x88, 0xD9, 0xE9, 0x7C, 0x4C, 0x1D, 0x2D]
// table[ 64..127] >> 8 & 0xFF
const TABLE_B1_Q1: byte[64] = [
0x41, 0x71, 0x20, 0x10, 0x85, 0xB5, 0xE4, 0xD4,
0xC9, 0xF9, 0xA8, 0x98, 0x0D, 0x3D, 0x6C, 0x5C,
0x51, 0x61, 0x30, 0x00, 0x95, 0xA5, 0xF4, 0xC4,
0xD9, 0xE9, 0xB8, 0x88, 0x1D, 0x2D, 0x7C, 0x4C,
0x61, 0x51, 0x00, 0x30, 0xA5, 0x95, 0xC4, 0xF4,
0xE9, 0xD9, 0x88, 0xB8, 0x2D, 0x1D, 0x4C, 0x7C,
0x71, 0x41, 0x10, 0x20, 0xB5, 0x85, 0xD4, 0xE4,
0xF9, 0xC9, 0x98, 0xA8, 0x3D, 0x0D, 0x5C, 0x6C]
// table[128..191] >> 8 & 0xFF
const TABLE_B1_Q2: byte[64] = [
0x83, 0xB3, 0xE2, 0xD2, 0x47, 0x77, 0x26, 0x16,
0x0B, 0x3B, 0x6A, 0x5A, 0xCF, 0xFF, 0xAE, 0x9E,
0x93, 0xA3, 0xF2, 0xC2, 0x57, 0x67, 0x36, 0x06,
0x1B, 0x2B, 0x7A, 0x4A, 0xDF, 0xEF, 0xBE, 0x8E,
0xA3, 0x93, 0xC2, 0xF2, 0x67, 0x57, 0x06, 0x36,
0x2B, 0x1B, 0x4A, 0x7A, 0xEF, 0xDF, 0x8E, 0xBE,
0xB3, 0x83, 0xD2, 0xE2, 0x77, 0x47, 0x16, 0x26,
0x3B, 0x0B, 0x5A, 0x6A, 0xFF, 0xCF, 0x9E, 0xAE]
// table[192..255] >> 8 & 0xFF
const TABLE_B1_Q3: byte[64] = [
0xC2, 0xF2, 0xA3, 0x93, 0x06, 0x36, 0x67, 0x57,
0x4A, 0x7A, 0x2B, 0x1B, 0x8E, 0xBE, 0xEF, 0xDF,
0xD2, 0xE2, 0xB3, 0x83, 0x16, 0x26, 0x77, 0x47,
0x5A, 0x6A, 0x3B, 0x0B, 0x9E, 0xAE, 0xFF, 0xCF,
0xE2, 0xD2, 0x83, 0xB3, 0x26, 0x16, 0x47, 0x77,
0x6A, 0x5A, 0x0B, 0x3B, 0xAE, 0x9E, 0xCF, 0xFF,
0xF2, 0xC2, 0x93, 0xA3, 0x36, 0x06, 0x57, 0x67,
0x7A, 0x4A, 0x1B, 0x2B, 0xBE, 0x8E, 0xDF, 0xEF]
// -----------------------------------------------------------------------
// CRC32 table — byte 2 of each 32-bit entry.
// -----------------------------------------------------------------------
// table[ 0.. 63] >> 16 & 0xFF
const TABLE_B2_Q0: byte[64] = [
0x00, 0x07, 0x0E, 0x09, 0x6D, 0x6A, 0x63, 0x64,
0xDB, 0xDC, 0xD5, 0xD2, 0xB6, 0xB1, 0xB8, 0xBF,
0xB7, 0xB0, 0xB9, 0xBE, 0xDA, 0xDD, 0xD4, 0xD3,
0x6C, 0x6B, 0x62, 0x65, 0x01, 0x06, 0x0F, 0x08,
0x6E, 0x69, 0x60, 0x67, 0x03, 0x04, 0x0D, 0x0A,
0xB5, 0xB2, 0xBB, 0xBC, 0xD8, 0xDF, 0xD6, 0xD1,
0xD9, 0xDE, 0xD7, 0xD0, 0xB4, 0xB3, 0xBA, 0xBD,
0x02, 0x05, 0x0C, 0x0B, 0x6F, 0x68, 0x61, 0x66]
// table[ 64..127] >> 16 & 0xFF
const TABLE_B2_Q1: byte[64] = [
0xDC, 0xDB, 0xD2, 0xD5, 0xB1, 0xB6, 0xBF, 0xB8,
0x07, 0x00, 0x09, 0x0E, 0x6A, 0x6D, 0x64, 0x63,
0x6B, 0x6C, 0x65, 0x62, 0x06, 0x01, 0x08, 0x0F,
0xB0, 0xB7, 0xBE, 0xB9, 0xDD, 0xDA, 0xD3, 0xD4,
0xB2, 0xB5, 0xBC, 0xBB, 0xDF, 0xD8, 0xD1, 0xD6,
0x69, 0x6E, 0x67, 0x60, 0x04, 0x03, 0x0A, 0x0D,
0x05, 0x02, 0x0B, 0x0C, 0x68, 0x6F, 0x66, 0x61,
0xDE, 0xD9, 0xD0, 0xD7, 0xB3, 0xB4, 0xBD, 0xBA]
// table[128..191] >> 16 & 0xFF
const TABLE_B2_Q2: byte[64] = [
0xB8, 0xBF, 0xB6, 0xB1, 0xD5, 0xD2, 0xDB, 0xDC,
0x63, 0x64, 0x6D, 0x6A, 0x0E, 0x09, 0x00, 0x07,
0x0F, 0x08, 0x01, 0x06, 0x62, 0x65, 0x6C, 0x6B,
0xD4, 0xD3, 0xDA, 0xDD, 0xB9, 0xBE, 0xB7, 0xB0,
0xD6, 0xD1, 0xD8, 0xDF, 0xBB, 0xBC, 0xB5, 0xB2,
0x0D, 0x0A, 0x03, 0x04, 0x60, 0x67, 0x6E, 0x69,
0x61, 0x66, 0x6F, 0x68, 0x0C, 0x0B, 0x02, 0x05,
0xBA, 0xBD, 0xB4, 0xB3, 0xD7, 0xD0, 0xD9, 0xDE]
// table[192..255] >> 16 & 0xFF
const TABLE_B2_Q3: byte[64] = [
0x64, 0x63, 0x6A, 0x6D, 0x09, 0x0E, 0x07, 0x00,
0xBF, 0xB8, 0xB1, 0xB6, 0xD2, 0xD5, 0xDC, 0xDB,
0xD3, 0xD4, 0xDD, 0xDA, 0xBE, 0xB9, 0xB0, 0xB7,
0x08, 0x0F, 0x06, 0x01, 0x65, 0x62, 0x6B, 0x6C,
0x0A, 0x0D, 0x04, 0x03, 0x67, 0x60, 0x69, 0x6E,
0xD1, 0xD6, 0xDF, 0xD8, 0xBC, 0xBB, 0xB2, 0xB5,
0xBD, 0xBA, 0xB3, 0xB4, 0xD0, 0xD7, 0xDE, 0xD9,
0x66, 0x61, 0x68, 0x6F, 0x0B, 0x0C, 0x05, 0x02]
// -----------------------------------------------------------------------
// CRC32 table — byte 3 (MSB) of each 32-bit entry.
// -----------------------------------------------------------------------
// table[ 0.. 63] >> 24 & 0xFF
const TABLE_B3_Q0: byte[64] = [
0x00, 0x77, 0xEE, 0x99, 0x07, 0x70, 0xE9, 0x9E,
0x0E, 0x79, 0xE0, 0x97, 0x09, 0x7E, 0xE7, 0x90,
0x1D, 0x6A, 0xF3, 0x84, 0x1A, 0x6D, 0xF4, 0x83,
0x13, 0x64, 0xFD, 0x8A, 0x14, 0x63, 0xFA, 0x8D,
0x3B, 0x4C, 0xD5, 0xA2, 0x3C, 0x4B, 0xD2, 0xA5,
0x35, 0x42, 0xDB, 0xAC, 0x32, 0x45, 0xDC, 0xAB,
0x26, 0x51, 0xC8, 0xBF, 0x21, 0x56, 0xCF, 0xB8,
0x28, 0x5F, 0xC6, 0xB1, 0x2F, 0x58, 0xC1, 0xB6]
// table[ 64..127] >> 24 & 0xFF
const TABLE_B3_Q1: byte[64] = [
0x76, 0x01, 0x98, 0xEF, 0x71, 0x06, 0x9F, 0xE8,
0x78, 0x0F, 0x96, 0xE1, 0x7F, 0x08, 0x91, 0xE6,
0x6B, 0x1C, 0x85, 0xF2, 0x6C, 0x1B, 0x82, 0xF5,
0x65, 0x12, 0x8B, 0xFC, 0x62, 0x15, 0x8C, 0xFB,
0x4D, 0x3A, 0xA3, 0xD4, 0x4A, 0x3D, 0xA4, 0xD3,
0x43, 0x34, 0xAD, 0xDA, 0x44, 0x33, 0xAA, 0xDD,
0x50, 0x27, 0xBE, 0xC9, 0x57, 0x20, 0xB9, 0xCE,
0x5E, 0x29, 0xB0, 0xC7, 0x59, 0x2E, 0xB7, 0xC0]
// table[128..191] >> 24 & 0xFF
const TABLE_B3_Q2: byte[64] = [
0xED, 0x9A, 0x03, 0x74, 0xEA, 0x9D, 0x04, 0x73,
0xE3, 0x94, 0x0D, 0x7A, 0xE4, 0x93, 0x0A, 0x7D,
0xF0, 0x87, 0x1E, 0x69, 0xF7, 0x80, 0x19, 0x6E,
0xFE, 0x89, 0x10, 0x67, 0xF9, 0x8E, 0x17, 0x60,
0xD6, 0xA1, 0x38, 0x4F, 0xD1, 0xA6, 0x3F, 0x48,
0xD8, 0xAF, 0x36, 0x41, 0xDF, 0xA8, 0x31, 0x46,
0xCB, 0xBC, 0x25, 0x52, 0xCC, 0xBB, 0x22, 0x55,
0xC5, 0xB2, 0x2B, 0x5C, 0xC2, 0xB5, 0x2C, 0x5B]
// table[192..255] >> 24 & 0xFF
const TABLE_B3_Q3: byte[64] = [
0x9B, 0xEC, 0x75, 0x02, 0x9C, 0xEB, 0x72, 0x05,
0x95, 0xE2, 0x7B, 0x0C, 0x92, 0xE5, 0x7C, 0x0B,
0x86, 0xF1, 0x68, 0x1F, 0x81, 0xF6, 0x6F, 0x18,
0x88, 0xFF, 0x66, 0x11, 0x8F, 0xF8, 0x61, 0x16,
0xA0, 0xD7, 0x4E, 0x39, 0xA7, 0xD0, 0x49, 0x3E,
0xAE, 0xD9, 0x40, 0x37, 0xA9, 0xDE, 0x47, 0x30,
0xBD, 0xCA, 0x53, 0x24, 0xBA, 0xCD, 0x54, 0x23,
0xB3, 0xC4, 0x5D, 0x2A, 0xB4, 0xC3, 0x5A, 0x2D]
}