Suggestion: epa-file-select-keys should show currently selected keys

Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Hi *,

I like the new epa-file features to work transparently on gpg encrypted
files.  What could be improved is the management of the recipient to
encrypt to:

1. Am I right that `M-x epa-file-select-keys' can be used to change the
   recipients in an existing *.gpg file?  If so, that should be
   documented more clearly (and might be worth an default binding?)

2. If `epa-file-select-keys' is called on an existing gpg file it showld
   show the currently used recipients as marked.

cheers
sascha
-- 
Sascha Wilde   -.-. ..- .-. .. --- ... .. - -.-- 
               -.- .. .-.. .-.. . -.. 
               - .... .
               -.-. .- -

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Richard Stallman]

It would be a good idea to check mailcrypt and make sure that oga
provides fully equivalent functionality.  Also that it works
with all the various packages, including Rmail and Gnus.

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Richard Stallman <rms@gnu.org> wrote:

> It would be a good idea to check mailcrypt and make sure that oga
> provides fully equivalent functionality.  Also that it works
> with all the various packages, including Rmail and Gnus.

I agree.  But I don't see how this is related to the subject of my
original mail.  Does mailcrypt provide the functionality I'm missing?

cheers
sascha
-- 
Sascha Wilde 
- no sig today... sorry!

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Sascha Wilde <wilde@sha-bang.de> wrote:
> 1. Am I right that `M-x epa-file-select-keys' can be used to change the
>    recipients in an existing *.gpg file?  If so, that should be
>    documented more clearly (and might be worth an default binding?)

Unfortunately it seems that I'm mistaken:
- Open an existing *.gpg file
- do M-x epa-file-select-keys and select some keys
- do any change, so that saving is possible (a problem on its own, as
  changing the list of recipients should be considered a relevant change
  it self)
- C-x C-s leads to an error:

Debugger entered--Lisp error: (file-error "Opening output file" stringp
(epg-key . [ultimate ((epg-sub-key . [ultimate (sign certify) nil 17
1024 "BB2185144BB86568" (16792 . 47982) nil
"8C21030737FBEB0CA0AFDC90BB2185144BB86568"]) (epg-sub-key . [ultimate
(encrypt) nil 16 2048 "31A16202F8F7E674" (16792 . 48001) nil
"F82F26DB68EF79BDC859377131A16202F8F7E674"])) ((epg-user-id . [ultimate
"Sascha Wilde <sascha.wilde@intevation.de>" nil]) (epg-user-id
. [ultimate "Sascha Wilde <Sascha.Wilde@intevation.de>" nil])
(epg-user-id . [ultimate "Sascha Wilde (Dienstlicher Key)
<wilde@intevation.de>" nil]))]))
  signal(file-error ("Opening output file" stringp (epg-key . [ultimate
  ... ...])))
  byte-code("Ä\"‰\nÅ¡ˆÆÇÈAB\"‡" [file epa-file-passphrase-alist
  entry error assoc nil signal file-error "Opening output file"] 4)
  epa-file-write-region(1 157
  "/tmp/foo.gpg" nil t)
  apply(epa-file-write-region (1 157
  "/tmp/foo.gpg" nil t))
  epa-file-handler(write-region 1 157
  "/tmp/foo.gpg" nil t)
  write-region(1 157 "/tmp/foo.gpg"
  nil t "/tmp/foo.gpg")
  basic-save-buffer-2()
  basic-save-buffer-1()
  basic-save-buffer()
  save-buffer(1)
  call-interactively(save-buffer nil nil)

So is there any comfortable way at all to change the list of recipients?

cheers
sascha
-- 
Sascha Wilde
"The primary difference [...] is that the Java program will reliably
and obviously crash, whereas the C program will do something obscure."  
   -- Java Language Tutorial

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Richard Stallman]

    > It would be a good idea to check mailcrypt and make sure that oga
    > provides fully equivalent functionality.  Also that it works
    > with all the various packages, including Rmail and Gnus.

    I agree.  But I don't see how this is related to the subject of my
    original mail.

It doesn't relate to your specific issue, it is only about the same
Lisp package.  But your message reminded me about this.

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Daiki Ueno]

>>>>> In <m28x18834s.fsf@kenny.sha-bang.de> 
>>>>>	Sascha Wilde <wilde@sha-bang.de> wrote:
> Sascha Wilde <wilde@sha-bang.de> wrote:
> > 1. Am I right that `M-x epa-file-select-keys' can be used to change the
> >    recipients in an existing *.gpg file?  If so, that should be
> >    documented more clearly (and might be worth an default binding?)

> Unfortunately it seems that I'm mistaken:
> - Open an existing *.gpg file
> - do M-x epa-file-select-keys and select some keys
> - do any change, so that saving is possible (a problem on its own, as
>   changing the list of recipients should be considered a relevant change
>   it self)
> - C-x C-s leads to an error:

> Debugger entered--Lisp error: (file-error "Opening output file" stringp
> (epg-key . [ultimate ((epg-sub-key . [ultimate (sign certify) nil 17

Ah, that is apperantly a bug.  The attached patch will fix this.

Index: lisp/epa-file.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/epa-file.el,v
retrieving revision 1.4
diff -w -c -r1.4 epa-file.el
*** lisp/epa-file.el	10 Feb 2008 20:57:46 -0000	1.4
--- lisp/epa-file.el	27 Feb 2008 08:06:23 -0000
***************
*** 285,294 ****
    (interactive)
    (make-local-variable 'epa-file-encrypt-to)
    (setq epa-file-encrypt-to
  	(epa-select-keys
  	 (epg-make-context)
  	 "Select recipents for encryption.
! If no one is selected, symmetric encryption will be performed.  ")))
  
  ;;;###autoload
  (defun epa-file-enable ()
--- 285,297 ----
    (interactive)
    (make-local-variable 'epa-file-encrypt-to)
    (setq epa-file-encrypt-to
+ 	(mapcar
+ 	 (lambda (key)
+ 	   (epg-sub-key-id (car (epg-key-sub-key-list key))))
  	 (epa-select-keys
  	  (epg-make-context)
  	  "Select recipents for encryption.
! If no one is selected, symmetric encryption will be performed.  "))))
  
  ;;;###autoload
  (defun epa-file-enable ()

Anyway, thanks for your suggestions.  I'll look at them this weekend
since I've been a bit busy now.

Regards,
-- 
Daiki Ueno

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Daiki Ueno]

>>>>> In <E1JTia2-0001ig-5X@fencepost.gnu.org> 
>>>>>	Richard Stallman <rms@gnu.org> wrote:
> It would be a good idea to check mailcrypt and make sure that oga
> provides fully equivalent functionality.  Also that it works
> with all the various packages, including Rmail and Gnus.

I'll look at mailcrypt.

For Rmail, I would like someone familiar with Rmail to check.  The key
bindings in mail-mode are described in "(epa) Mail-mode integration".

Gnus has used EasyPG as its default PGP backend since the initial merge.
I would also like to know if there is really no problem about it.

Regards,
-- 
Daiki Ueno

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Daiki Ueno <ueno@unixuser.org> wrote:

>>>>>> In <m28x18834s.fsf@kenny.sha-bang.de> 
>>>>>>	Sascha Wilde <wilde@sha-bang.de> wrote:
>> Sascha Wilde <wilde@sha-bang.de> wrote:
>> > 1. Am I right that `M-x epa-file-select-keys' can be used to change the
>> >    recipients in an existing *.gpg file?  If so, that should be
>> >    documented more clearly (and might be worth an default binding?)
>
>> Unfortunately it seems that I'm mistaken:
[...]
>> Debugger entered--Lisp error: (file-error "Opening output file" stringp
>> (epg-key . [ultimate ((epg-sub-key . [ultimate (sign certify) nil 17
>
> Ah, that is apperantly a bug.  The attached patch will fix this.

Thanks, that fixes it.

> Anyway, thanks for your suggestions.  I'll look at them this weekend
> since I've been a bit busy now.

Thanks again.  I'm looking forward for your suggestions...  :-)

cheers
sascha
-- 
Sascha Wilde 
- no sig today... sorry!

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Richard Stallman]

    For Rmail, I would like someone familiar with Rmail to check.  The key
    bindings in mail-mode are described in "(epa) Mail-mode integration".

Could you remember to keep track of whether someone has actually done
this, and if not, make reminders?

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Daiki Ueno]

2008/2/28 Richard Stallman <rms@gnu.org>:
>     For Rmail, I would like someone familiar with Rmail to check.  The key
>     bindings in mail-mode are described in "(epa) Mail-mode integration".
>
>  Could you remember to keep track of whether someone has actually done
>  this, and if not, make reminders?

Sure.  Since I have barely used Rmail, I really appreciate if someone
will check this.

Regards,
-- 
Daiki Ueno

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Bastien]

Daiki Ueno <ueno@unixuser.org> writes:

>>>>>> In <E1JTia2-0001ig-5X@fencepost.gnu.org> 
>>>>>>	Richard Stallman <rms@gnu.org> wrote:
>> It would be a good idea to check mailcrypt and make sure that oga
>> provides fully equivalent functionality.  Also that it works
>> with all the various packages, including Rmail and Gnus.
>
> For Rmail, I would like someone familiar with Rmail to check.  The key
> bindings in mail-mode are described in "(epa) Mail-mode integration".

I will implement EasyPG support for Rmail.

BTW, I see there are many warnings like 

  "Don't use this code in Lisp programs!"

inside the docstrings of epa-*.el defuns.  
Are all those warnings necessary?  

> Gnus has used EasyPG as its default PGP backend since the initial merge.
> I would also like to know if there is really no problem about it.

I'm using EasyPG/Gnus since the merge with no problem at all.

-- 
Bastien

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Richard Stallman]

    BTW, I see there are many warnings like 

      "Don't use this code in Lisp programs!"

    inside the docstrings of epa-*.el defuns.  
    Are all those warnings necessary?  

Does it say why?

This could be analogous to the warning in the function goto-beginning:
there's a cleaner, simpler way for Lisp programs to do it.

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Daiki Ueno]

>>>>> In <87skzdi3pw.fsf@bzg.ath.cx> 
>>>>>	Bastien <bzg@altern.org> wrote:
> Daiki Ueno <ueno@unixuser.org> writes:
> > For Rmail, I would like someone familiar with Rmail to check.  The key
> > bindings in mail-mode are described in "(epa) Mail-mode integration".

> I will implement EasyPG support for Rmail.

Thanks.  Please let me know if you feel uneasy when using the library.

> BTW, I see there are many warnings like 

>   "Don't use this code in Lisp programs!"

> inside the docstrings of epa-*.el defuns.  
> Are all those warnings necessary?  

I would say yes.  The rationale is:

The library functions of EasyPG are designed to work on strings and
files rather than buffers, because implicit data conversion depending on
buffer's multibyteness is sometimes an impediment for binary data
handling.  All functions which have those warnings work on buffers.  The
buffer based commands also do automatic detection of coding-systems.

So I would recommend to use string based API instead of these commands
for reliable data handling.

> I'm using EasyPG/Gnus since the merge with no problem at all.

That's good.

Regards,
-- 
Daiki Ueno

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Stefan Monnier]

> The library functions of EasyPG are designed to work on strings and
> files rather than buffers, because implicit data conversion depending on
> buffer's multibyteness is sometimes an impediment for binary data
> handling.  All functions which have those warnings work on buffers.  The
> buffer based commands also do automatic detection of coding-systems.

Then the docstring should point to the closest alternative function that
should usually be used instead.


        Stefan

EasyPG API and usage questions (was: Suggestion: epa-file-select-keys should show currently selected keys)

[Ted Zlatanov]

On Fri, 29 Feb 2008 13:07:39 +0900 Daiki Ueno <ueno@unixuser.org> wrote: 

DU> The library functions of EasyPG are designed to work on strings and
DU> files rather than buffers, because implicit data conversion depending on
DU> buffer's multibyteness is sometimes an impediment for binary data
DU> handling.  All functions which have those warnings work on buffers.  The
DU> buffer based commands also do automatic detection of coding-systems.

DU> So I would recommend to use string based API instead of these commands
DU> for reliable data handling.

Hello,

I want to replace encrypt.el with EasyPG in netrc.el (in Gnus and later
also in Emacs).  Can you explain how to replace this

(let ((encryption-model 
       (when (netrc-bound-and-true-p encrypt-file-alist)
	 (encrypt-find-model file))))

  (if encryption-model
      (encrypt-insert-file-contents file encryption-model)
    (insert-file-contents file)))

with the equivalent EasyPG string-based or buffer-based functions?

It seems like (insert (epg-decrypt-string ...)) or
epa-file-insert-file-contents is the way to do it (probably the second
one), but I'd like to be sure I'm following the recommended usage.
Should netrc.el use the epa-* or epg-* interface?

In addition to writing the code, I have to document the new behavior of
netrc.el and explain to its users how to set up an encrypted netrc file.
Is there a guide for epa-file.el users that want to use that
functionality?  The epa.texi file doesn't seem to cover
epa-file-name-regexp for example, to explain what will happen with files
that match, and how to create such files with various options (see
below).  By the way, epa-file-name-regexp should be a list of regular
expressions and filenames, so the users can add something easily to the
list.

Generally the EasyPG user documentation is very bare, so I had a hard
time understanding how to use it.  Is there additional documentation
outside of epa.texi?  Specifically, as a user I couldn't figure out how
to do the following from inside EasyPG:

- how do I specify a particular cipher?

- how do I specify symmetric encryption?

- how do I specify plaintext instead of binary output?

- how do I generate a GPG key?  (I realize GPG will do it, but epa.texi
  just says you can import keys without explaining)

http://www.easypg.org and http://sourceforge.jp/projects/epg/ had no
documentation or mailing lists I could search.  I can get some of the
answers by reading the source code, but I'm wondering if there's
documentation I've missed, and if you can answer these questions where
the documentation doesn't.

Thanks
Ted

Re: EasyPG API and usage questions (was: Suggestion: epa-file-select-keys should show currently selected keys)

[Daiki Ueno]

2008/3/1, Ted Zlatanov <tzz@lifelogs.com>:
>  I want to replace encrypt.el with EasyPG in netrc.el (in Gnus and later
>  also in Emacs).  Can you explain how to replace this
>
>  (let ((encryption-model
>        (when (netrc-bound-and-true-p encrypt-file-alist)
>          (encrypt-find-model file))))
>
>   (if encryption-model
>       (encrypt-insert-file-contents file encryption-model)
>     (insert-file-contents file)))
>
>  with the equivalent EasyPG string-based or buffer-based functions?
>
>  It seems like (insert (epg-decrypt-string ...)) or
>  epa-file-insert-file-contents is the way to do it (probably the second
>  one), but I'd like to be sure I'm following the recommended usage.
>  Should netrc.el use the epa-* or epg-* interface?

Doesn't it work without any change?  epa-file changes
insert-file-contents behavior to decrypt *.gpg files automatically.

For example, I believe that the following code just works:

(epa-file-enable);; this may become (auto-encryption-mode t) in the future.

(setq nnimap-authinfo-file "~/.authinfo.gpg"
      nntp-authinfo-file "~/.authinfo.gpg"
      smtpmail-auth-credentials "~/.authinfo.gpg")

What feature do you want in addition to this?

>  functionality?  The epa.texi file doesn't seem to cover
>  epa-file-name-regexp for example, to explain what will happen with files
>  that match, and how to create such files with various options (see
>  below).  By the way, epa-file-name-regexp should be a list of regular
>  expressions and filenames, so the users can add something easily to the
>  list.

If all the custom-options should be documented in texi, I will do it.

>  Generally the EasyPG user documentation is very bare, so I had a hard
>  time understanding how to use it.  Is there additional documentation
>  outside of epa.texi?  Specifically, as a user I couldn't figure out how
>  to do the following from inside EasyPG:

Which are you talking about: user commands or API?

As the web-page says, EasyPG is consists of two different kinds of
components: EasyPG Assistant and EasyPG Library.  EasyPG Assistant is
an analog to GPA and EasyPG Library is an analog to GPGME.

Since IIRC Richard doesn't want API docs in texi, I only provide the
docs of EasyPG Assistant (user commands) and I think that epa.texi is
sufficient for typical users.

Anyway, a good starting point to use the EasyPG Library is the GPGME manual.

>  - how do I specify a particular cipher?

There is no such API in lisp level, since I doubt that there is any
practical use to select ciphers per data.  Is it not enough to put
cipher-algo option in ~/.gnupg/gpg.conf?

>  - how do I specify symmetric encryption?

Just pass nil as RECIPIENTS to the epg-encrypt-*.  This is documented
in their docstrings.

>  - how do I specify plaintext instead of binary output?

s/plaintext/ASCII armor/?  It can be done with:

(let ((epg-make-context 'OpenPGP))
  (epg-context-set-armor t)
  (epg-encrypt-string context "test test test" nil))

>  - how do I generate a GPG key?  (I realize GPG will do it, but epa.texi
>   just says you can import keys without explaining)

There are API functions epg-generate-key-from-*, but interactive
commands are missing.  Patches welcome.

Regards,
-- 
Daiki Ueno

Re: EasyPG API and usage questions (was: Suggestion: epa-file-select-keys should show currently selected keys)

[Daiki Ueno]

2008/3/1, Daiki Ueno <ueno@unixuser.org>:
>  >  - how do I specify plaintext instead of binary output?
>
> s/plaintext/ASCII armor/?  It can be done with:
>
>  (let ((epg-make-context 'OpenPGP))
>   (epg-context-set-armor t)
>   (epg-encrypt-string context "test test test" nil))

This is apparently wrong.  It should be:

(let ((context (epg-make-context 'OpenPGP)))
  (epg-context-set-armor context t)
  (epg-encrypt-string context "test test test" nil))

Sorry for the noise.
-- 
Daiki Ueno

Re: EasyPG API and usage questions

[Reiner Steib]

On Fri, Feb 29 2008, Ted Zlatanov wrote:

> I want to replace encrypt.el with EasyPG in netrc.el (in Gnus and later
> also in Emacs).

FWIW, "and later also in Emacs" might be misleading.  If you change
`lisp/netrc.el' in Gnus, the change will end up in Emacs (`lisp/net/netrc.el')
after a couple of days (depending on Miles' time), too.

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/

Re: EasyPG API and usage questions

[Ted Zlatanov]

On Sat, 01 Mar 2008 11:20:13 +0100 Reiner Steib <reinersteib+gmane@imap.cc> wrote: 

RS> On Fri, Feb 29 2008, Ted Zlatanov wrote:
>> I want to replace encrypt.el with EasyPG in netrc.el (in Gnus and later
>> also in Emacs).

RS> FWIW, "and later also in Emacs" might be misleading.  If you change
RS> `lisp/netrc.el' in Gnus, the change will end up in Emacs (`lisp/net/netrc.el')
RS> after a couple of days (depending on Miles' time), too.

That's what I meant, not that I'd do it personally.

Thanks
Ted

Re: EasyPG API and usage questions

[Ted Zlatanov]

On Sat, 1 Mar 2008 09:23:02 +0900 "Daiki Ueno" <ueno@unixuser.org> wrote: 

DU> 2008/3/1, Ted Zlatanov <tzz@lifelogs.com>:
>> I want to replace encrypt.el with EasyPG in netrc.el (in Gnus and later
>> also in Emacs).  Can you explain how to replace this
>> 
>> (let ((encryption-model
>> (when (netrc-bound-and-true-p encrypt-file-alist)
>> (encrypt-find-model file))))
>> 
>> (if encryption-model
>> (encrypt-insert-file-contents file encryption-model)
>> (insert-file-contents file)))
>> 
>> with the equivalent EasyPG string-based or buffer-based functions?
>> 
>> It seems like (insert (epg-decrypt-string ...)) or
>> epa-file-insert-file-contents is the way to do it (probably the second
>> one), but I'd like to be sure I'm following the recommended usage.
>> Should netrc.el use the epa-* or epg-* interface?

DU> Doesn't it work without any change?  epa-file changes
DU> insert-file-contents behavior to decrypt *.gpg files automatically.

Should we require users to override insert-file-contents to use
encryption with netrc.el?  It makes our life easier, but the user
doesn't have the choice to just use it for netrc.el anymore, he has to
turn it on globally.  I certainly don't know all the issues involved
here, so opinions are welcome.

DU> For example, I believe that the following code just works:

DU> (epa-file-enable);; this may become (auto-encryption-mode t) in the future.

DU> (setq nnimap-authinfo-file "~/.authinfo.gpg"
DU>       nntp-authinfo-file "~/.authinfo.gpg"
DU>       smtpmail-auth-credentials "~/.authinfo.gpg")

DU> What feature do you want in addition to this?

Just the choice of cipher, and a way to limit the epa-file-enable effect
to the insert only (pending discussion above).  I think specifying
symmetric encryption at the epa-file level would be nice too.

>> functionality?  The epa.texi file doesn't seem to cover
>> epa-file-name-regexp for example, to explain what will happen with files
>> that match, and how to create such files with various options (see
>> below).  By the way, epa-file-name-regexp should be a list of regular
>> expressions and filenames, so the users can add something easily to the
>> list.

DU> If all the custom-options should be documented in texi, I will do it.

If epa-file.el is a base Emacs feature, it should be documented so a
beginner can get started with it.  That doesn't mean every custom option
in depth necessarily, but some overview would be good.

>> - how do I specify a particular cipher?

DU> There is no such API in lisp level, since I doubt that there is any
DU> practical use to select ciphers per data.  Is it not enough to put
DU> cipher-algo option in ~/.gnupg/gpg.conf?

I don't know.  Can I say "I want all these files encrypted with light
encryption, but these with a better one"?  I think this is valuable
(yes, we already discussed this in the context of encrypt.el, but I
think the user should at least have some choice in the matter).  

It seems from reading the GPG docs that you can only set the algorithm
globally with gpg.conf, but I may have misunderstood.

For example, I want to store a Maildir spool encrypted and doing heavy
encryption is not practical at that scale, but my .authinfo file should
be protected with the best cipher possible and it's tiny.

This is related to epa-file-name-regexp, which makes it difficult to add
multiple patterns to the list (especially for beginners).  To add the
Maildir, I'd need to modify the regexp.  Perhaps a epa-file-names
variable would be better, with options (regexp | directory | filename)
per entry.

>> - how do I specify symmetric encryption?

DU> Just pass nil as RECIPIENTS to the epg-encrypt-*.  This is documented
DU> in their docstrings.

OK.  I think it would be nice at the epa-file level too.  Do you mind if
I submit a patch, or do you want it always asymmetrical in epa-file, or
is there a way to do it I don't know?

>> - how do I specify plaintext instead of binary output?

DU> s/plaintext/ASCII armor/?  It can be done with:

DU> (let ((epg-make-context 'OpenPGP))
DU>   (epg-context-set-armor t)
DU>   (epg-encrypt-string context "test test test" nil))

OK, thanks (I saw your followup correction about this).

>> - how do I generate a GPG key?  (I realize GPG will do it, but epa.texi
>> just says you can import keys without explaining)

DU> There are API functions epg-generate-key-from-*, but interactive
DU> commands are missing.  Patches welcome.

Perhaps I could contribute later, when I have learned the library
better.

Thank you
Ted

Re: EasyPG API and usage questions

[Daiki Ueno]

>>>>> In <86bq5vd0gk.fsf@lifelogs.com> 
>>>>>	Ted Zlatanov <tzz@lifelogs.com> wrote:
DU> What feature do you want in addition to this?

> Just the choice of cipher, and a way to limit the epa-file-enable effect
> to the insert only (pending discussion above).

I think that it would not be too late to implement these features until
someone else really wants them.  The former is not even provided by
GPGME, GPA, etc., and I doubt the usefulness of the latter since other
file-name-handlers (jka-compr-handler and image-file-handler) don't
support it.  Do you have reasonable criteria to make an exception in
favor of epa-file-handler?

> I think specifying symmetric encryption at the epa-file level would be
> nice too.

No, epa-file already supports this.  You have never used epa-file,
have you?  It interactively asks you which encryption to use.

DU> If all the custom-options should be documented in texi, I will do it.

> If epa-file.el is a base Emacs feature, it should be documented so a
> beginner can get started with it.

Ok, I'll do.

Regards,
-- 
Daiki Ueno

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Sascha Wilde <wilde@sha-bang.de> wrote:
> Daiki Ueno <ueno@unixuser.org> wrote:

>>>>>>> In <m28x18834s.fsf@kenny.sha-bang.de> 
>>>>>>>	Sascha Wilde <wilde@sha-bang.de> wrote:
>>> Sascha Wilde <wilde@sha-bang.de> wrote:
>>> > 1. Am I right that `M-x epa-file-select-keys' can be used to change the
>>> >    recipients in an existing *.gpg file?  If so, that should be
>>> >    documented more clearly (and might be worth an default binding?)
>>
>>> Unfortunately it seems that I'm mistaken:
> [...]
>>> Debugger entered--Lisp error: (file-error "Opening output file" stringp
>>> (epg-key . [ultimate ((epg-sub-key . [ultimate (sign certify) nil 17
>>
>> Ah, that is apperantly a bug.  The attached patch will fix this.
>
> Thanks, that fixes it.
>
>> Anyway, thanks for your suggestions.  I'll look at them this weekend
>> since I've been a bit busy now.
>
> Thanks again.  I'm looking forward for your suggestions...  :-)

Why is the fix still not in HEAD?
If there is no good reason not to do it, please check it in.

cheers
sascha
-- 
Sascha Wilde : "Ist es nicht schon schlimm genug, dass ICH hier rumtrolle?"
             : (Henning Leise in d.o.c.)

Re: EasyPG API and usage questions

[Ted Zlatanov]

On Tue, 04 Mar 2008 15:31:17 +0900 Daiki Ueno <ueno@unixuser.org> wrote: 

>>>>>> In <86bq5vd0gk.fsf@lifelogs.com> 
>>>>>> Ted Zlatanov <tzz@lifelogs.com> wrote:
DU> What feature do you want in addition to this?

>> Just the choice of cipher, and a way to limit the epa-file-enable effect
>> to the insert only (pending discussion above).

DU> I think that it would not be too late to implement these features until
DU> someone else really wants them.  The former is not even provided by
DU> GPGME, GPA, etc.,

I don't think that just because a feature has not been done means it's
not useful.  I gave specific examples: I'd like to encrypt a Maildir
spool, and don't want to burn the CPU cycles necessary to use the
default cipher on it.  On the other hand, I want a good cipher (better
than the default if possible) applied to my passwords file.  If you
think those examples are only useful to me, I'll set up my own functions
to do it.  I think other users would like that kind of flexibility.

>> I think specifying symmetric encryption at the epa-file level would be
>> nice too.

DU> No, epa-file already supports this.  You have never used epa-file,
DU> have you?  It interactively asks you which encryption to use.

Here's what I did (before asking you those questions) from an Emacs CVS
checkout (epa-mode is t, and I also ran epa-file-enable):

C-x C-f file-with-content
C-x C-w /tmp/c.gpg
Use untrusted key? n
[aborted]

C-x C-f file-with-content
C-x C-w /tmp/c.gpg
Use untrusted key? y
.../tmp/c.gpg written and in current buffer...
M-x kill-buffer
C-x C-f /tmp/c.gpg
"File exists, but cannot be read"

At this point I was in the /tmp/c.gpg buffer, it was read-only, but had
no content.

Here I assumed I need to set up GPG keys (I have none) and gave up.  I
looked at epa.texi and didn't see a solution.  I also tried M-x
epa-encrypt-file instead of the C-x C-w direct write, and got the same
results.  I was never asked about symmetric encryption AFAIK.  Is the
"untrusted key" question about symmetric encryption?

If I missed a way to do symmetric encryption in the above, please let me
know.  I appreciate your help.

Thanks
Ted

Re: EasyPG API and usage questions

[Daiki Ueno]

>>>>> In <867igiblec.fsf@jumptrading.com> 
>>>>>	Ted Zlatanov <tzz@lifelogs.com> wrote:
DU> I think that it would not be too late to implement these features until
DU> someone else really wants them.  The former is not even provided by
DU> GPGME, GPA, etc.,

> I don't think that just because a feature has not been done means it's
> not useful.  I gave specific examples: I'd like to encrypt a Maildir
> spool, and don't want to burn the CPU cycles necessary to use the
> default cipher on it.  On the other hand, I want a good cipher (better
> than the default if possible) applied to my passwords file.  If you
> think those examples are only useful to me, I'll set up my own functions
> to do it.  I think other users would like that kind of flexibility.

Well, please don't make a hypothesis.  Do you really see any performance
issues in your use cases?  Do you really see significant relevance
between speed and strength of ciphers which GnuPG supports?

I tried each cipher to encrypt 46MiB linux-2.6.24.tar.bz2, and got the
following result: 3DES 4.201s, CAST5 1.558s, BLOWFISH 2.628s, AES
1.901s, AES192 1.988, AES256 2.108s, and TWOFISH 2.029s.  Here the
fastest algorithm is CAST5 (128bit key), and the longest key length
algorithm is AES256.  The time difference of them are only 0.55s (1/4 of
AES256's).  The difference will decrease if the inputs are relatively
small files in mail spools.

> >> I think specifying symmetric encryption at the epa-file level would be
> >> nice too.

DU> No, epa-file already supports this.  You have never used epa-file,
DU> have you?  It interactively asks you which encryption to use.

> Here's what I did (before asking you those questions) from an Emacs CVS
> checkout (epa-mode is t, and I also ran epa-file-enable):
[...]
> Here I assumed I need to set up GPG keys (I have none) and gave up.

Ah, that's a bug.  Thanks for finding it in the corner case.  Here is a
patch to fix this.

Index: lisp/epa.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/epa.el,v
retrieving revision 1.6
diff -c -r1.6 epa.el
*** lisp/epa.el	12 Feb 2008 01:24:20 -0000	1.6
--- lisp/epa.el	5 Mar 2008 07:16:21 -0000
***************
*** 542,551 ****
  NAMES is a list of strings to be matched with keys.  If it is nil, all
  the keys are listed.
  If SECRET is non-nil, list secret keys instead of public keys."
!   (let ((keys (epg-list-keys context names secret)))
!     (if (> (length keys) 1)
! 	(epa--select-keys prompt keys)
!       keys)))
  
  (defun epa--show-key (key)
    (let* ((primary-sub-key (car (epg-key-sub-key-list key)))
--- 542,548 ----
  NAMES is a list of strings to be matched with keys.  If it is nil, all
  the keys are listed.
  If SECRET is non-nil, list secret keys instead of public keys."
!   (epa--select-keys prompt (epg-list-keys context names secret)))
  
  (defun epa--show-key (key)
    (let* ((primary-sub-key (car (epg-key-sub-key-list key)))

Regards,
-- 
Daiki Ueno

Re: EasyPG API and usage questions

[Ted Zlatanov]

On Wed, 05 Mar 2008 16:25:22 +0900 Daiki Ueno <ueno@unixuser.org> wrote: 

>>>>>> In <867igiblec.fsf@jumptrading.com> 
>>>>>> Ted Zlatanov <tzz@lifelogs.com> wrote:
DU> I think that it would not be too late to implement these features until
DU> someone else really wants them.  The former is not even provided by
DU> GPGME, GPA, etc.,

>> I don't think that just because a feature has not been done means it's
>> not useful.  I gave specific examples: I'd like to encrypt a Maildir
>> spool, and don't want to burn the CPU cycles necessary to use the
>> default cipher on it.  On the other hand, I want a good cipher (better
>> than the default if possible) applied to my passwords file.  If you
>> think those examples are only useful to me, I'll set up my own functions
>> to do it.  I think other users would like that kind of flexibility.

DU> Well, please don't make a hypothesis.  Do you really see any performance
DU> issues in your use cases?  Do you really see significant relevance
DU> between speed and strength of ciphers which GnuPG supports?

DU> I tried each cipher to encrypt 46MiB linux-2.6.24.tar.bz2, and got the
DU> following result: 3DES 4.201s, CAST5 1.558s, BLOWFISH 2.628s, AES
DU> 1.901s, AES192 1.988, AES256 2.108s, and TWOFISH 2.029s.  Here the
DU> fastest algorithm is CAST5 (128bit key), and the longest key length
DU> algorithm is AES256.  The time difference of them are only 0.55s (1/4 of
DU> AES256's).  The difference will decrease if the inputs are relatively
DU> small files in mail spools.

Right, because of startup costs.  Incidentally, is there a way to reduce
those by keeping GPG running continuously?  I couldn't find it in the
manual, but it will probably make a much bigger difference than the
cipher type.

I agree the difference is small, but it's measurable.  If you think it's
not useful to implement this, then let's drop the suggestion as we did
the other one (selective enabling of epa-file).

Ted

Re: EasyPG API and usage questions

[Ted Zlatanov]

On Wed, 05 Mar 2008 16:25:22 +0900 Daiki Ueno <ueno@unixuser.org> wrote: 

DU> Ah, that's a bug.  Thanks for finding it in the corner case.  Here is a
DU> patch to fix this.
DU> Index: lisp/epa.el
DU> ===================================================================
DU> RCS file: /sources/emacs/emacs/lisp/epa.el,v
DU> retrieving revision 1.6
DU> diff -c -r1.6 epa.el
DU> *** lisp/epa.el	12 Feb 2008 01:24:20 -0000	1.6
DU> --- lisp/epa.el	5 Mar 2008 07:16:21 -0000
DU> ***************
DU> *** 542,551 ****
DU>   NAMES is a list of strings to be matched with keys.  If it is nil, all
DU>   the keys are listed.
DU>   If SECRET is non-nil, list secret keys instead of public keys."
DU> !   (let ((keys (epg-list-keys context names secret)))
DU> !     (if (> (length keys) 1)
DU> ! 	(epa--select-keys prompt keys)
DU> !       keys)))
  
DU>   (defun epa--show-key (key)
DU>     (let* ((primary-sub-key (car (epg-key-sub-key-list key)))
DU> --- 542,548 ----
DU>   NAMES is a list of strings to be matched with keys.  If it is nil, all
DU>   the keys are listed.
DU>   If SECRET is non-nil, list secret keys instead of public keys."
DU> !   (epa--select-keys prompt (epg-list-keys context names secret)))
  
DU>   (defun epa--show-key (key)
DU>     (let* ((primary-sub-key (car (epg-key-sub-key-list key)))

I can confirm this fixes the bug, I hope you can commit it soon.

It's very nice that if I cancel the encryption, I remain in the file.gpg
buffer, but it's unsaved.  If I try to save again, it brings up the save
dialog again.

If I open a symetrically encrypted file.gpg and write it to another
file1.gpg, I never get a question about the encryption.  EasyPG assumes
I want symmetric encryption again.  I don't know if that's a feature or
a bug.

Can the passphrase and symmetric encryption/key choice be automatically
cached for a whole directory of files, if it's entered for any one of
them?  That way I can have ~/Maildir-crypt/{cur,tmp,new} encrypted
consistently, for example.

In the key selection buffer, (described as "Major mode for
`epa-list-keys'") I think it would be nice to have

C-c C-c and Enter anywhere (except the "Cancel" button or on a key)
equivalent to "OK"

C-c C-k equivalent to "Cancel"

Thanks
Ted

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Sascha Wilde]

Sascha Wilde <wilde@sha-bang.de> wrote:
> Sascha Wilde <wilde@sha-bang.de> wrote:
>> Daiki Ueno <ueno@unixuser.org> wrote:
>
>>>>>>>> In <m28x18834s.fsf@kenny.sha-bang.de> 
>>>>>>>>	Sascha Wilde <wilde@sha-bang.de> wrote:
>>>> Sascha Wilde <wilde@sha-bang.de> wrote:
>>>> > 1. Am I right that `M-x epa-file-select-keys' can be used to change the
>>>> >    recipients in an existing *.gpg file?  If so, that should be
>>>> >    documented more clearly (and might be worth an default binding?)
>>>
>>>> Unfortunately it seems that I'm mistaken:
>> [...]
>>>> Debugger entered--Lisp error: (file-error "Opening output file" stringp
>>>> (epg-key . [ultimate ((epg-sub-key . [ultimate (sign certify) nil 17
>>>
>>> Ah, that is apperantly a bug.  The attached patch will fix this.
>>
>> Thanks, that fixes it.
>>
>>> Anyway, thanks for your suggestions.  I'll look at them this weekend
>>> since I've been a bit busy now.
>>
>> Thanks again.  I'm looking forward for your suggestions...  :-)
>
> Why is the fix still not in HEAD?
> If there is no good reason not to do it, please check it in.

Ping.

Sorry, I don't intend to be a nuisance, but this fix seems to be still
missing from HEAD.  Why?

I would be very grateful if it could be committed.

cheers
sascha
-- 
Sascha Wilde

"There is no reason why anyone would want a computer in their home"
Ken Olson, DEC, 1977

Re: Suggestion: epa-file-select-keys should show currently selected keys

[Michael Olson]

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Sascha Wilde <wilde@sha-bang.de> writes:

> Ping.
>
> Sorry, I don't intend to be a nuisance, but this fix seems to be still
> missing from HEAD.  Why?
>
> I would be very grateful if it could be committed.

Fix checked in.

-- 
|       Michael Olson  |  FSF Associate Member #652     |
| http://mwolson.org/  |  Hobbies: Lisp, HCoop          |
| Projects: Emacs, Muse, ERC, EMMS, ErBot, DVC, Planner |
`-------------------------------------------------------'

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