external password backend does not work with special characters

[npiazza at disroot.org]

On Mon, May 06, 2024 at 02:09:45PM -0400, npiazza at disroot.org wrote:
> with a long password that contains special characters, the wpa_supplicant
> can connect to the network if using
> 
> password="mypassword"
> 
> in the .config file (i.e. the actual password enclosed in quotation marks)
> but not if using
> 
> password=ext:pwd_eduroam
> 
> with the external password file containing a line
> 
> pwd_eduroam=mypassword
> 
> without quotation marks.  I also tried and failed with quotation marks
> 
> pwd_eduroam="mypassword"
> 
> The external file works correctly with other networks, or simpler/shorter
> passwords on this network.
> 
> Are there any restrictions on the characters allowed in the external file
> backend, compared to the regular .conf file, or am I doing something wrong,
> or missing some recently added patch?
> 
> Thanks.

After some experiments, I think what breaks the external file backend
is the presence of a # character in the password field.  This seems to
work for me in wpa_supplicant.conf but not in the external file.  If so,
is this a well-known limitation or a bug?  (tested on v2.11)