Changing hashes when switching JVM version

[rutchkiwi]

Hi! Thanks for writing this library!

I just upgraded my JVM version from java 1.8 to openjdk 11, and with that change the hashes generated by the digest/md5 function changed.

This creates a problem for me, as I use this library for generating hashes that are used to check uniqueness of images uploaded into a system. (by storing the generated hashed in a database)

Is this expected behaviour?

Thanks!

[tebeka]

Thanks @rutchkiwi ! I'm not aware of the changes to MD5 in JDK11, will investigate.

[rutchkiwi]

Great, thank you! :) If it helps I'm hashing java.io.files and byte arrays - both their hashes changed.

[tebeka]

I don't see a difference:

JDK 11

root@12f28f5aef6b:/# ./lein repl
nREPL server started on port 46203 on host 127.0.0.1 - nrepl://127.0.0.1:46203
REPL-y 0.4.3, nREPL 0.5.3
Clojure 1.8.0
OpenJDK 64-Bit Server VM 11.0.1+13-Debian-3
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=> (load-file "digest.clj")
nil
user=> (digest/md5 "hello")
"5d41402abc4b2a76b9719d911017c592"

JDK 8

root@f88c0777af13:/# ./lein repl
nREPL server started on port 35125 on host 127.0.0.1 - nrepl://127.0.0.1:35125
REPL-y 0.4.3, nREPL 0.5.3
Clojure 1.8.0
OpenJDK 64-Bit Server VM 1.8.0_181-8u181-b13-2~deb9u1-b13
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=> (load-file "digest.clj")
nil
user=> (digest/md5 "hello")
"5d41402abc4b2a76b9719d911017c592"

[rutchkiwi]

Hmm odd - I'll come back to you with a concrete test case in a bit.

[rutchkiwi]

Hi @tebeka after looking into this a bit futher and trying to make a concrete test case, it seems that in fact my problem is not with this library 😬 but rather that something else in the JDK has changed (I'm hashing images after some processing - probably somewhere in this processing something changed).

I'm really sorry for wasting you time.

Thank you very much for the help, and for this library!

[tebeka]

No worries, thanks for using clj-digest and reporting problems.