CODEWITHSUNDEEP
c#utf-8sha256
user3667122
user3667122

Reputation: 124

Converted to and form UTF8 after SHA256 yields different results, why?

var test = "sdfsdfsdfasfwerqwer";

var q = UTF8Encoding.UTF8.GetBytes(test);

var sha256 = SHA256.Create();

var hash = sha256.ComputeHash(q);

var z = UTF8Encoding.UTF8.GetString(hash);

var t = UTF8Encoding.UTF8.GetBytes(z);

In the above example, hash and t have different values. Why is this?

Upvotes: 0

Views: 1039

Answers (1)

fejesjoco
fejesjoco

Reputation: 11903

hash is not an UTF-8 encoded byte array, just some random bytes. Note: not all byte arrays are valid as UTF-8, UTF-8 has its own rules. Therefore, it cannot necessarily be decoded into a string. (Specifically, invalid bytes are usually decoded into a question mark in .NET.)

You can try a regular 8-bit encoding which supports all possible byte arrays, like ISO-8859-1. Of course you will still get garbage when you try to read that as a string, but it should work back and forth.

If you are trying to transfer a random byte array as a string, I suggest you use BASE-64 encoding, which converts byte arrays to an ASCII string, which should be safe in all circumstances.

Upvotes: 4

Related Questions