Create two different binaries with same size and same md5 hash

Question

I have two different files: code1.c and code2.c, both of them already contain some C code (files contents differ).

I would like to compile both files preferably with the same compilation flags so I will end up with two binaries which would have same size and same md5 hash.

Note: It is allowed to add extra dead/junk code to one of the files. I think gcc compiler version should not matter? (I would use gcc version ≥ 7)

How can I achieve that?

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I found some articles which show that md5 hash collision is possible, but the problem is that it should result in the same file size:

• https://crypto.stackexchange.com/questions/1434/are-there-two-known-strings-which-have-the-same-md5-hash-value
• https://natmchugh.blogspot.com/2015/05/how-to-make-two-binaries-with-same-md5.html
• Can two different strings generate the same MD5 hash code?