pattern matching algorithm

[OHPen]

i think it's my fault,

i haven't explaned well what i need exactly.

OK:

2 Files:

1.exe (123.456 Byte)
2.exe (654.321 Byte)

Both packed with Packer/Crypter XYZ.
XYZ has a unique Signature 0xABCDEF12.

In 1.exe Signature can be found at offset 0x123.
In 2.exe Signature can be found at offset 0x321.

My question is:

Is there a tool or sourcecode which would be able to detect that 0xABCDEF12 is a Byte-Sequence which can be found in both files at different offsets.

That's exactly what im searchin for.

I have tested all of the tools you told me that they can,

but THEY CAN'T.

It's a problem so code such a "resyncronizing" compare algorithm, so i have to search a tool for it or have to find some source ( i love java )

regards

OHPen