URL-encode base64 encoded hash

[juergenhoetzel]

Base64 strings can contain "+", "=" and "/" characters.

Also use PHP for hash generation (like the showcased symfony code).

[juergenhoetzel]

$ grep ^APP_SECRET .env 
APP_SECRET=2d196390accfb409bd1091203a572531
$ python3 -c "import base64, hmac, hashlib; print(base64.b64encode(hmac.HMAC(b'2d196390accfb409bd1091203a572531', b'http://localhost:8000/_fragment', hashlib.sha256).digest()))"
b'aluwOeeQHfCCQvO8IpQBah0UwshTEzLVYE4T+uJYi3c='

The existing code did not work for my APP_SECRET because of the special char + in the Base64 encoding.

[carlospolop]

thanks!