Clarify what character encoding is used in the returned UI strings

When not used any more, the returned method should be freed with

UI_destroy_method().

=head1 NOTES

UI_UTIL_read_pw_string() and UI_UTIL_read_pw() use default

B<UI_METHOD>.

See L<UI_get_default_method(3)> and friends for more information.

The result from the B<UI_METHOD> created by

UI_UTIL_wrap_read_pem_callback() will generate password strings in the

encoding that the given password callback generates.

The default password prompting functions (apart from

UI_UTIL_read_pw_string() and UI_UTIL_read_pw(), there is

PEM_def_callback(), EVP_read_pw_string() and EVP_read_pw_string_min())

all use the default B<UI_METHOD>.

=head1 SEE ALSO

L<UI_get_default_method(3)>

=head1 COPYRIGHT

Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.

UI_new_method() creates a new UI using the given UI method.  When done with

this UI, it should be freed using UI_free().

UI_OpenSSL() returns the built-in UI method (note: not the default one,

since the default can be changed.  See further on).  This method is the

most machine/OS dependent part of OpenSSL and normally generates the

most problems when porting.

UI_OpenSSL() returns the built-in UI method (note: not necessarely the

default one, since the default can be changed.  See further on).  This

method is the most machine/OS dependent part of OpenSSL and normally

generates the most problems when porting.

UI_null() returns a UI method that does nothing.  Its use is to avoid

getting internal defaults for passed UI_METHOD pointers.

UI_free() removes a UI from memory, along with all other pieces of memory

that's connected to it, like duplicated input strings, results and others.

UI_set_method() changes the UI method associated with a given UI.

UI_OpenSSL() is the default OpenSSL UI method for prompting

passphrases on the command line.

=head1 NOTES

UI_null() is a UI method that does nothing.  Its use is to avoid

getting internal defaults for passed UI_METHOD pointers.

The resulting strings that the built in method UI_OpenSSL() generate

are assumed to be encoded according to the current locale or (for

Windows) code page.

For applications having different demands, these strings need to be

converted appropriately by the caller.

For Windows, if the OPENSSL_WIN32_UTF8 environment variable is set,

the built-in method UI_OpenSSL() will produce UTF-8 encoded strings

instead.

=head1 COPYRIGHT