Hi Michael, When I issue the command I get a prompt for the password -the same thing that happens when trying to connect through tramp- and, in this case, I get the password that I enter, returned as a string to the minibuffer and the *Messages Buffer*. When I write the password it is masked with asterisks, but the string returned is readable -as I imagine it could not be in any other way-.
In summary, the read-passwd function seems to be working as expected. The question is then why tramp gets trapped on asking for the password, that is, why, after having inserted te password it asks for it again as if it was not correct. The thing is that it continues to ask for the password even after the third trial, which normally is the point where all these password requests stop. I am going to look for some other WebDAV server that I may have access to to make some additional tests. To see if the problem are WebDAV servers in general or this one in particular. I would appreciate if you know of some free service that may serve me to test this. As always, thank you very much for your help. Best Manuel