pascalvault / lazarus_hashing

Checksum & Hashing library for Lazarus

Checksum & Hashing library for Lazarus

The goal is the create a library which is modular, fast and portable. There is no platform-specific code, no Assembly, no includes, no conditinal defines. Every algorith has it's own separate file and if you need just one algorithm in your program you can just copy 2 files- the file with the algorithm you need and "HasherBase.pas". Optionally you can copy "Hasher.pas" but that's just a helper class.

Available algorithms

More soon...

• CRC-4 interlaken,
• CRC-6 DARC, CRC-6 G704,
• CRC-7 mmc, CRC-7 umts,
• CRC-8 AUTOSAR, CRC-8 BLUETOOTH, CRC-8 CDMA2000, CRC-8 DARC, CRC-8 DVBS2, CRC-8 GSMA, CRC-8 GSMB, CRC-8 HITAG, CRC-8 I4321, CRC-8 ICODE, CRC-8 LTE, CRC-8 MAXIMDOW, CRC-8 MIFAREMAD, CRC-8 NRSC5, CRC-8 OPENSAFETY, CRC-8 ROHC, CRC-8 SAEJ1850, CRC-8 SMBUS, CRC-8 TECH3250, CRC-8 WCDMA,
• CRC-10 atm, CRC-10 gsm, CRC-10 cdma2000,
• CRC-11 flexray, CRC-11 umts,
• CRC-12 gsm, CRC-12 dect, CRC-12 cdma2000,
• CRC-13 bbc,
• CRC-14 gsm,
• CRC-15 can, CRC-15 MPT1327,
• CRC-16 ARC, CRC-16 CDMA2000, CRC-16 CMS, CRC-16 DDS110, CRC-16 DECTR, CRC-16 DECTX, CRC-16 DNP, CRC-16 EN13757, CRC-16 GENIBUS, CRC-16 GSM, CRC-16 IBM3740, CRC-16 IBMSDLC, CRC-16 KERMIT, CRC-16 LJ1200, CRC-16 M17, CRC-16 MAXIMDOW, CRC-16 MCRF4XX, CRC-16 MODBUS, CRC-16 NRSC5, CRC-16 OPENSAFETYA, CRC-16 OPENSAFETYB, CRC-16 PROFIBUS, CRC-16 SPIFUJITSU, CRC-16 T10DIF, CR-C16 TELEDISK, CRC-16 UMTS, CRC-16 USB, CRC-16 XMODEM,
• CRC-17 canfd,
• CRC-21 canfd,
• CRC-24 OS9, CRC-24 FLEXRAYA, CRC-24 FLEXRAYB, CRC-24 INTERLAKEN, CRC-24 LTEA, CRC-24 LTEB, CRC-24 OPENPGP,
• CRC-30 cdma,
• CRC-31 philips,
• CRC-32 MPEG2, CRC32 JAMCRC,
• CRC-40 gsm,
• CRC-64, CRC-64 ecma, CRC-64 go, CRC-64 ecma 182, CRC-64 xz, CRC-64 ms,
• CRC-82 darc,
• Adler8, Adler16, Adler32, Adler64,
• cksum mpeg2,
• Fletcher8, Fletcher16, Fletcher32, Fletcher64,
• SIZE64, Sum BSD, Sum SYSV,
• SUM8, SUM16, SUM24, SUM32, SUM64,
• XOR8, XOR16, XOR32
• xxHash32
• MurmurHash, MurmurHash2, MurmurHash2a, MurmurHash3
• SHA-0, SHA-1, SHA-224, SHA-256

PHP port available

https://github.com/PascalVault/PHP_Hashing

Usage examples

hashing a String

uses Hasher;

var Hasher: THasher;
    Hash: String;
begin
  try
    Hasher := THasher.Create('CRC-32 JAMCRC');
    Hasher.Update('123456789');
    Hash := Hasher.Final;
    Hasher.Free;
    
    Memo1.Lines.Add( Hash );
  finally
  end; 

hashing a Stream

uses Hasher;

var Hasher: THasher;
    Hash: String;
    Msg: TMemoryStream;
begin
  try
    Msg := TMemoryStream.Create;
    Hasher := THasher.Create('CRC-32 JAMCRC');
    Hasher.Update(Msg);
    Hash := Hasher.Final;
    Hasher.Free;
    
    Memo1.Lines.Add( Hash );
  finally
    Msg.Free;
  end; 

hashing a file

 uses Hasher;

var Hasher: THasher;
    Hash: String;
begin
  try       
    Hasher := THasher.Create('CRC-32 JAMCRC');
    Hasher.UpdateFile('directory/file.exe');
    Hash := Hasher.Final;
    Hasher.Free;
    
    Memo1.Lines.Add( Hash );
  finally
  end; 

Using classes directly- without THasher

hashing a String

uses CRC64;

var Hasher: THasherCRC64;
    Hash: String;
    Msg: String;
begin
  Msg := '123456789';
  Hasher := THasherCRC64.Create;
  Hasher.Update(@Msg[1], Length(Msg));
  Hash := Hasher.Final;
  Hasher.Free;

  Memo1.Lines.Add( Hash );
end;

hashing an Array

uses CRC64;

var Hasher: THasherCRC64;
    Hash: String;
    Msg: array of Byte;
    Len: Integer;
begin
  SetLength(Msg, Len);
  Hasher := THasherCRC64.Create;
  Hasher.Update(@Msg[0], Len);
  Hash := Hasher.Final;
  Hasher.Free;

  Memo1.Lines.Add( Hash );
end;

lazarus_hashing's Issues

little incorrect try/finally block

  try
    Algo := FClass.Create;
    Algo.Update(@Test[0], 9);
    Res := Algo.Final;

    if Algo.Check = Res then Result := True;
  finally
    Algo.Free;
  end;

move line Algo:= BEFORE try, common practice, more correct.

maybe use TStringList.CaseSensitive

function THasherList.FindClass(Name: String; out AClass: THasherClass): Boolean;
var Index: Integer;
begin
  Name := LowerCase(Name);

with CaseSensitive, you can avoid LowerCase

add helper method IsIndexValid

adding helper func will help in places like this:

function THasherList.GetName(Index: Integer): String;
begin
  if (Index > FList.Count-1) or (Index < 0) then Result := ''

add LICENSE.txt file to the github repo, pls

maybe make the Lazarus package?

.lpk file. Making it will allow to use the package and src-folder will be auto included the the proj. no need to copy files into proj dir.

before doing LPK file, pls move all .pas files to 'src' folder and include pas files from there. LPK file can be inside 'src' too.

small optim here?

function THasherList.FindClass(Name: String; out AClass: THasherClass): Boolean;
var Index: Integer;
begin
  Name := LowerCase(Name);
  Index := FList.IndexOf(Name);

FList.IndexOf(LowerCase(Name)) and make Name the const-param.

will be nice to add a 'prefix' to filenames

..., like e.g. Hashing or at least Hash. this allows to avoid collision of filenames in big projects.