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doc/emacs/misc.texi (Network Security): Improve wording and indexing.

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Eli Zaretskii 2014-11-24 20:07:51 +02:00
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doc/emacs/ChangeLog
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@ -1,3 +1,8 @@
2014-11-24 Eli Zaretskii <eliz@gnu.org>
* misc.texi (Network Security): Improve wording and indexing of
last change.
2014-11-24 Lars Magne Ingebrigtsen <larsi@gnus.org>
* misc.texi (Gnus Summary Buffer): Move the Network Security

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doc/emacs/misc.texi
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@ -252,27 +252,30 @@ Exit the summary buffer and return to the group buffer.
@node Network Security
@section Network Security
@cindex Network Security Manager
@cindex network security manager
@cindex NSM
@cindex encryption
@cindex SSL
@cindex TLS
@cindex STARTTLS
After establishing a network connection, the connection is then passed
on to the Network Security Manager (@acronym{NSM}).
Whenever Emacs establishes any network connection, it passes the
established connection to the @dfn{Network Security Manager}
(@acronym{NSM}). @acronym{NSM} is responsible for enforcing the
network security under your control.
@vindex network-security-level
The @code{network-security-level} variable determines the security
level. If this is @code{low}, no security checks are performed.
level that @acronym{NSM} enforces. If its value is @code{low}, no
security checks are performed.
If this variable is @code{medium} (which is the default), a number of
checks will be performed. If the @acronym{NSM} determines that the
network connection might be unsafe, the user is made aware of this,
and the @acronym{NSM} will ask the user what to do about the network
connection.
checks will be performed. If as result @acronym{NSM} determines that
the network connection might be unsafe, it will make you aware of
that, and will ask you what to do about the network connection.
The user is given the choice of registering a permanent security
exception, a temporary one, or whether to refuse the connection
You can decide to register a permanent security exception for an
unsafe connection, a temporary exception, or refuse the connection
entirely.
Below is a list of the checks done on the @code{medium} level.
@ -281,24 +284,23 @@ Below is a list of the checks done on the @code{medium} level.
@item unable to verify a @acronym{TLS} certificate
If the connection is a @acronym{TLS}, @acronym{SSL} or
@acronym{STARTTLS} connection, the @acronym{NSM} will check whether
@acronym{STARTTLS} connection, @acronym{NSM} will check whether
the certificate used to establish the identity of the server we're
connecting to can be verified.
While an invalid certificate is often the cause for concern (there may
be a Man-in-the-Middle hijacking your network connection and stealing
your password), there may be valid reasons for going ahead with the
connection anyway.
For instance, the server may be using a self-signed certificate, or
the certificate may have expired. It's up to the user to determine
whether it's acceptable to continue the connection.
While an invalid certificate is often the cause for concern (there
could be a Man-in-the-Middle hijacking your network connection and
stealing your password), there may be valid reasons for going ahead
with the connection anyway. For instance, the server may be using a
self-signed certificate, or the certificate may have expired. It's up
to you to determine whether it's acceptable to continue with the
connection.
@item a self-signed certificate has changed
If you've previously accepted a self-signed certificate, but it has
now changed, that either means that the server has just changed the
certificate, or this might mean that the network connection has been
hijacked.
now changed, that could mean that the server has just changed the
certificate, but it might also mean that the network connection has
been hijacked.
@item previously encrypted connection now unencrypted
If the connection is unencrypted, but it was encrypted in previous
@ -311,44 +313,44 @@ When connecting to an @acronym{IMAP} or @acronym{POP3} server, these
should usually be encrypted, because it's common to send passwords
over these connections. Similarly, if you're sending email via
@acronym{SMTP} that requires a password, you usually want that
connection to be encrypted. If the connection isn't encrypted, the
connection to be encrypted. If the connection isn't encrypted,
@acronym{NSM} will warn you.
@end table
If @code{network-security-level} is @code{high}, the following checks
will be made:
will be made, in addition to the above:
@table @asis
@item a validated certificate changes the public key
Servers change their keys occasionally, and that is normally nothing
to be concerned about. However, if you are worried that your network
connections are being hijacked by agencies who have access to pliable
Certificate Authorities that issue new certificates for third-party
Certificate Authorities which issue new certificates for third-party
services, you may want to keep track of these changes.
@end table
Finally, if @code{network-security-level} is @code{paranoid}, you will
also be notified the first time the @acronym{NSM} sees any new
also be notified the first time @acronym{NSM} sees any new
certificate. This will allow you to inspect all the certificates from
all the connections that Emacs makes.
The following additional variables can be used to control
@acronym{NSM} details.
The following additional variables can be used to control details of
@acronym{NSM} operation:
@table @code
@item nsm-settings-file
@vindex nsm-settings-file
The @acronym{NSM} stores details on the connections in this file. It
defaults to @file{~/.emacs.d/network-security.data}.
This is the file where @acronym{NSM} stores details about connections.
It defaults to @file{~/.emacs.d/network-security.data}.
@item nsm-save-host-names
@vindex nsm-save-host-names
By default, host names will not be saved per non-@code{STARTTLS}
connection. Instead a host/port hash is used to identify connections.
By default, host names will not be saved for non-@code{STARTTLS}
connections. Instead a host/port hash is used to identify connections.
This means that one can't casually read the settings file to see what
servers the user has connected to. If this variable is @code{t}, host
names will be saved in the file, too.
servers the user has connected to. If this variable is @code{t},
@acronym{NSM} will also save host names in the nsm-settings-file.
@end table