(require 'epa-setup)
-Then you can do some cryptographic operations on dired.
+Then you can browse your keyring by `M-x epa-list-keys'. In addition,
+you can do some cryptographic operations on dired.
M-x dired
(mark some files)
* Security consideration
-** `call-process-region' writes data in region to a temporary file
+** Passphrase may leak to a temporary file.
`call-process-region' writes data in region to a temporary file.
-EasyPG does *not* use `call-process-region' to communicate with a gpg
+The EasyPG Library does not use `call-process-region' to communicate with a gpg
subprocess.
-** `(fillarray string 0)' is not enough to clear passphrases
+** There is no way to clear passphrase safely.
-If Emacs crashed and dumps core, passphrase strings in memory are also
+If Emacs crashes and dumps core, Lisp strings in memory are also
dumped within the core file. `read-passwd' function clears passphrase
strings by `(fillarray string 0)'. However, Emacs performs compaction
in gc_sweep phase. If GC happens before `fillarray', passphrase
-strings may be moved elsewhere in memory.
+strings may be moved elsewhere in memory. Therefore, passphrase
+caching in elisp is generally a bad idea.
-Fortunately, there is gpg-agent to cache passphrases in more secure
-way, so the EasyPG Library dares *not* to cache passphrase by itself.
-Elisp programs can set `epg-context-passphrase-callback' to cache
-user's passphrases.
+The EasyPG Library dares to disable passphrase caching. Fortunately,
+there is more secure way to cache passphrases - use gpg-agent. Elisp
+programs can set `epg-context-passphrase-callback' to cache user's
+passphrases, it is not recommended though.
projects / elisp / epg.git / blobdiff