How do I hash a string with Delphi?

Question

How do I make an MD5 hash of a string with Delphi?

Answer 1

If you want an MD5 digest and have the Indy components installed, you can do this:

uses SysUtils, IdGlobal, IdHash, IdHashMessageDigest;

with TIdHashMessageDigest5.Create do
try
    Result := TIdHash128.AsHex(HashValue('Hello, world'));
finally
    Free;
end;

Most popular algorithms are supported in the Delphi Cryptography Package:

• Haval
• MD4, MD5
• RipeMD-128, RipeMD-160
• SHA-1, SHA-256, SHA-384, SHA-512,
• Tiger

Update DCPCrypt is now maintained by Warren Postma and source can be found here.

Answer 2

If you want an MD5 hash string as hexadeciamal and you have Delphi XE 1 installed, so you have Indy 10.5.7 components you can do this:

uses IdGlobal, IdHash, IdHashMessageDigest;

class function getMd5HashString(value: string): string;
var
    hashMessageDigest5 : TIdHashMessageDigest5;
begin
    hashMessageDigest5 := nil;
    try
        hashMessageDigest5 := TIdHashMessageDigest5.Create;
        Result := IdGlobal.IndyLowerCase ( hashMessageDigest5.HashStringAsHex ( value ) );
    finally
        hashMessageDigest5.Free;
    end;
end;

Answer 3

Why not use the system.Hash unit from RTL, that contains also a hash algorithm for MD5 since Delphi Seattle?

MD5HashCode := THashMD5.GetHashString(ClearTextString);

Answer 4

I usually use DCPCrypt2 (Delphi Cryptography Package) from David Barton (City in the Sky).

It is also contains the following Encryption Algorithms:

• Blowfish
• Cast 128
• Cast 256
• DES, 3DES
• Ice, Thin Ice, Ice2
• IDEA
• Mars
• Misty1
• RC2, RC4, RC5, RC6
• Rijndael (the new AES)
• Serpent
• Tea
• Twofish

Update DCPCrypt is now maintained by Warren Postma and source can be found here.

Answer 5

This is a modification of devstopfix's answer which was accepted.

In current Indy version you can hash strings and streams more easily. Example:

function MD5String(str: String): String;
begin
  with TIdHashMessageDigest5.Create do
    try
      Result := HashStringAsHex(str);
    finally
      Free;
    end;
end;

Use HashString, HashStringAsHex, HashBytes, HashBytesAsHex, HashStream, HashStreamAsHex. The advantage is that you can also specify a text encoding

Answer 6

Spring For Delphi project - http://www.spring4d.org - has implementation for a number of SHAxxx hashes, MD5 hash, and also number of CRC functions

Answer 7

If all you want to do is use a dictionary, and you're not looking for security then:
In Delphi 2009 and higher, hash values for strings can be created with

BobJenkinsHash(Value, Length(Value) * SizeOf(Value), 0)

where Value is a string.

http://docwiki.embarcadero.com/VCL/en/Generics.Defaults.BobJenkinsHash

Answer 8

You can also use the WindowsCrypto API with Delphi:

• General Crypto & Hash demo and resources

There is a unit in there that wraps all the CryptoAPI. You can also use Lockbox, which is now open source.

In the end you can support pretty much any Hash algorithms with Delphi. The Indy example is probably the closest you will get to natively in Delphi since Indy is included with most versions of Delphi. For the rest you will need to either use a library or write some more code to access the CryptoAPI or implement it yourself.

Answer 9

TurboPower Lockbox supports:

• MD-5,
• SHA-1 and
• the entire SHA-2 family including the recently published SHA-512/224 & SHA-512/256 hashes.

Answer 10

Using ICS, you simply call StrMD5 function which is located in OverbytecsMD5 unit.

Beside that specific function, there are a lot more MD5 function for other datatypes and scenarios. There are also other hash methods such as SHA.