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I'm hashing a password in Java using google's Hashing. 

password = Hashing
        .sha256()
        .hashString(input, StandardCharsets.UTF_8)
        .toString();

When I pass any text to that line, it hashes and outputs everything with lowercase characters, for example, if I pass "foo", the value of password becomes:

2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae

However, if I use this site to hash "foo", the value it outputs is

2C26B46B68FFC68FF99B453C1D30413413422D706483BFA0F98A5E886266E7AE

As far as I can tell that's just the exact same password except with uppercase letters instead of lowercase.

What's causing those to output different values, and how can I get guava to output with uppercase letters (without just calling toUpperCase, unless that's really the only way)

realmature
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    They're hex digits, and case isn't semantically significant. – chrylis -cautiouslyoptimistic- Nov 30 '18 at 18:47
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    It is simply hex-encoding of binary data. Hex-encoding does not specify upper-/lower-case, because it doesn't matter to hex-encoding. If you compare the hex-encoded string, *you* need to do a case-insensitive comparison, or *you* need to standardize on either upper or lower case. – Andreas Nov 30 '18 at 18:47
  • Cool, thanks. The explanation was really what I was asking for. I already knew I could just call toUpperCase – realmature Nov 30 '18 at 18:53

1 Answers1

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The main reason why Guava is making the result string in lower case, is because of the implementation of: com.google.common.hash.HashCode.toString() method.

You can simply call toUpperCase() method, from String class, on your result hash string value:

password = Hashing
        .sha256()
        .hashString(input, StandardCharsets.UTF_8)
        .toString()
        .toUpperCase();
Aleksandr Podkutin
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