PASSWORD_ARGON2I constant undefined in 7.2-alpine

[forevermatt]

While testing password_hash() in PHP 7.2, I noticed that the 7.2-alpine Docker image seems to lack the PASSWORD_ARGON2I constant.

Example of error:

$ docker run --rm -it library/php:7.2-alpine ash
/ # php -r "echo PASSWORD_ARGON2I . PHP_EOL;"

Warning: Use of undefined constant PASSWORD_ARGON2I - assumed 'PASSWORD_ARGON2I' (this will throw an Error in a future version of PHP) in Command line code on line 1
PASSWORD_ARGON2I

Example of expected behavior (using the 7.2 image):

$ docker run --rm -it library/php:7.2 bash
root@068d1b669538:/# php -r "echo PASSWORD_ARGON2I . PHP_EOL;"
2

I don't know if it's related to the LibreSSL configuration discussion here, but this seemed worth mentioning since the new password hashing stuff is one of the great benefits of PHP 7.2

[yosifkit]

From #515 (comment)

Looks like the library is libargon2-0-dev in Debian -- it's in Alpine also (argon2-dev), but only in edge.

Unfortunately this is still true, so perhaps with Alpine 3.8 we can have the argon2 library.

[TBK]

Create an issue on https://bugs.alpinelinux.org/ and it might get backported.

[tianon]

I think updating to Alpine 3.8 (now that it's released) is probably our best bet forward here (ala #683).

[TimWolla]

I think updating to Alpine 3.8 (now that it's released) is probably our best bet forward here (ala #683).

Yes, #677 adds support for Argon 2 to the Alpine 3.8 based images: 7e230c9

[tianon]

Woot, this is fixed (and will be published once docker-library/official-images#4752 merges). 👍

Thanks @TimWolla and @forevermatt!