Why crypto.createHash returns different output in new version?

Question

Problem

I have node.js module that is using crypto.createHash to generate md5 hash.

Recently I noticed that hash g

Answer 1

Some inputs in Node v6+ calculate a different hash than previous Node versions.

Basically, when you pass a string to .update(), with Node versions before v6 the default encoding was binary, but for Node v6 that changed to utf-8.

For example, take this code:

require('crypto').createHash('md5').update('¥').digest('hex')

This outputs ab3af8566ffffd20d7efc9b314abe90755 on Node pre-6 and 07625e142e4ac5961de57472657a88c1 on Node 6.

If you want Node 6 to output the same as pre-6 versions, you have to tell .update() to use binary encoding:

require('crypto').createHash('md5').update('¥', 'binary').digest('hex')

Or the other way around (make Node pre-6 output the same as 6):

require('crypto').createHash('md5').update('¥', 'utf-8').digest('hex')

Answer 2

Just like mark this issue in github: https://github.com/nodejs/node/issues/6813 is about the default encoding for digests that was changed to utf8 in v5/v6 and in v4 and earlier it was binary