Min Password Length vs Block Common Passwords

[mpalmer (Matt Palmer)]

My bet there is that the client-side validation is counting octets, whereas the server, being Unicode-aware, is counting characters, and coming up with a different result.

[elijah (Eli the Bearded)]

Characters in that codeblock (and indeed all of U+1xxxx) are four-octets long in UTF-8. I don’t know what it’s counting, but Unicode 7/Unicode 8 issues (like amphora) could be in play.

[david (David Taylor)]

Taking the string " " as an example, javascript says

"😀".length = 2

and Ruby says

"😀".length = 1

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Which is the correct implementation here? @codinghorror's blog post says:

Enforce a minimum Unicode password length

because it’s nice and simple for users. So is one character. That sounds reasonable to me.

However… the blog also says

If you paste the above four Unicode emojis into your favorite login dialog (go ahead – try it), to discover that it … isn’t in fact four characters.

This is indeed true of the Discourse password fields - one emoji = 2 characters. So if it’s showing as 2 characters in the password field, surely that should count as 2 characters in a password

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On a related note, it is currently very difficult to type emojis directly into html password inputs - you can only copy/paste them in. This is the case on Chrome on mac (using system emoji window), and also Safari on iOS (the emoji button doesn’t even show up with the password field focused). So, as much as I try, I can’t use as my password on Discourse (without cheating with copy/paste).

[elijah (Eli the Bearded)]

😀 is four octets in UTF-8: Base64 visualizer

I have no idea why Javascript gets that count. (UTF-16?) But 😀 does show as ⏺⏺ in the password field of Discourse (for me).

[david (David Taylor)]

@elijah

UTF-16?

It would appear so (from here)

This property returns the number of code units in the string. UTF-16, the string format used by JavaScript, uses a single 16-bit code unit to represent the most common characters, but needs to use two code units for less commonly-used characters, so it’s possible for the value returned by length to not match the actual number of characters in the string.

[fedup]

A sentence with spaces - could be the best personal password choice

[Mittineague]

I’m not sure a space would work. It’s a control character and there might be some filters somewhere that wouldn’t like it.

[david (David Taylor)]

@Mittineague

I’m not sure a space would work

A space is absolutely fine, it’s just another character as far as a password is concerned. Try it here on meta - it works.

[Alt-Elijah (Elijah's Alternate)]

@Alt-Elijah

Descubrí que el cuadro para cambiar la contraseña me muestra un mensaje verde de “correcto” tras introducir ocho caracteres del bloque “Símbolos misceláneos y pictogramas”, como y otros cercanos, pero al enviarlo cambia a un mensaje rojo de “demasiado corto”. Tengo que llegar a los diez caracteres completos, incluso si todos son no-ASCII. Tras el cambio de contraseña, pude iniciar sesión tanto con Firefox como con Chromium.

Voy a probar de nuevo, ahora que sé que mi gestor de contraseñas está seguro. Ahora ocurre lo mismo: la cantidad de emojis necesaria para que aparezca el mensaje verde de “correcto” no es suficiente para que funcione realmente. Y a medida que probaba contraseñas cada vez más largas, de forma iterativa, me cerró la sesión; creo que fue en el tercer intento. Cuando finalmente lo configuré con éxito, con una contraseña de emojis, aún parpadeó el mensaje de “te han cerrado la sesión”, pero en realidad no me cerró la sesión.

No estoy seguro de si ese cierre de sesión es un error específico de los emojis o alguna característica mal planteada (o al menos poco útil). Si es una característica, por favor, que el cuadro de “te han cerrado la sesión” explique por qué.

[riking (Kane York)]

Sí, esto se debe a una limitación heredada de JavaScript que hace que cuente incorrectamente la longitud de las cadenas que contienen emojis (y otros caracteres del Plano Astral). El servidor cuenta la longitud correctamente.