@c This is part of the Emacs manual.
-@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2012
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2015 Free Software
+@c Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Packages
@chapter Emacs Lisp Packages
@item
The package's status---normally one of @samp{available} (can be
-downloaded from the package archive), @samp{installed}, or
-@samp{built-in} (included in Emacs by default).
+downloaded from the package archive), @samp{installed},
+@c @samp{unsigned} (installed, but not signed; @pxref{Package Signing}),
+or @samp{built-in} (included in Emacs by default).
The status can also be @samp{new}. This is equivalent to
@samp{available}, except that it means the package became newly
Refresh the package list (@code{package-menu-refresh}). This fetches
the list of available packages from the package archive again, and
recomputes the package list.
+
+@item f
+Filter the package list (@code{package-menu-filter}). This prompts
+for a keyword (e.g., @samp{games}), then shows only the packages
+that relate to that keyword. To restore the full package list,
+type @kbd{q}.
@end table
@noindent
wish to use third party package archives---but do so at your own risk,
and use only third parties that you think you can trust!
+@anchor{Package Signing}
+@cindex package security
+@cindex package signing
+ The maintainers of package archives can increase the trust that you
+can have in their packages by @dfn{signing} them. They generate a
+private/public pair of cryptographic keys, and use the private key to
+create a @dfn{signature file} for each package. With the public key, you
+can use the signature files to verify who created the package, and
+that it has not been modified. A valid signature is not a cast-iron
+guarantee that a package is not malicious, so you should still
+exercise caution. Package archives should provide instructions
+on how you can obtain their public key. One way is to download the
+key from a server such as @url{http://pgp.mit.edu/}.
+Use @kbd{M-x package-import-keyring} to import the key into Emacs.
+Emacs stores package keys in the @file{gnupg} subdirectory
+of @code{package-user-dir}.
+The public key for the GNU package archive is distributed with Emacs,
+in the @file{etc/package-keyring.gpg}. Emacs uses it automatically.
+
+@vindex package-check-signature
+@vindex package-unsigned-archives
+ If the user option @code{package-check-signature} is non-@code{nil},
+Emacs attempts to verify signatures when you install packages. If the
+option has the value @code{allow-unsigned}, you can still install a
+package that is not signed. If you use some archives that do not sign
+their packages, you can add them to the list @code{package-unsigned-archives}.
+
+ For more information on cryptographic keys and signing,
+@pxref{Top,, Top, gnupg, The GNU Privacy Guard Manual}.
+Emacs comes with an interface to GNU Privacy Guard,
+@pxref{Top,, EasyPG, epa, Emacs EasyPG Assistant Manual}.
+
+@vindex package-pinned-packages
+ If you have more than one package archive enabled, and some of them
+offer different versions of the same package, you may find the option
+@code{package-pinned-packages} useful. You can add package/archive
+pairs to this list, to ensure that the specified package is only ever
+downloaded from the specified archive.
+
Once a package is downloaded and installed, it is @dfn{loaded} into
the current Emacs session. Loading a package is not quite the same as
loading a Lisp library (@pxref{Lisp Libraries}); its effect varies