security-and-privacy/gnupg
security-and-privacy/gnupg
1
0
Fork 0
mirror of git://git.gnupg.org/gnupg.git synced 2025-07-02 22:46:30 +02:00
Code Activity

gpg: Make the use of "--verify FILE" for detached sigs harder.

Browse source 
* g10/openfile.c (open_sigfile): Factor some code out to ...
(get_matching_datafile): new function.
* g10/plaintext.c (hash_datafiles): Do not try to find matching file
in batch mode.
* g10/mainproc.c (check_sig_and_print): Print a warning if a possibly
matching data file is not used by a standard signatures.
--

Allowing to use the abbreviated form for detached signatures is a long
standing bug which has only been noticed by the public with the
release of 2.1.0.  :-(

What we do is to remove the ability to check detached signature in
--batch using the one file abbreviated mode.  This should exhibit
problems in scripts which use this insecure practice.  We also print a
warning if a matching data file exists but was not considered because
the detached signature was actually a standard signature:

  gpgv: Good signature from "Werner Koch (dist sig)"
  gpgv: WARNING: not a detached signature; \
  file 'gnupg-2.1.0.tar.bz2' was NOT verified!

We can only print a warning because it is possible that a standard
signature is indeed to be verified but by coincidence a file with a
matching name is stored alongside the standard signature.

Reported-by: Simon Nicolussi (to gnupg-users on Nov 7)
Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2014-11-13 17:39:31 +01:00
parent 22748338da
commit 69384568f6
5 changed files with 125 additions and 51 deletions
Download patch file Download diff file Expand all files Collapse all files

5
g10/main.h
View file

@ -286,7 +286,8 @@ char *make_outfile_name( const char *iname );
char *ask_outfile_name( const char *name, size_t namelen );
int open_outfile (int inp_fd, const char *iname, int mode,
int restrictedperm, iobuf_t *a);
iobuf_t open_sigfile( const char *iname, progress_filter_context_t *pfx );
char *get_matching_datafile (const char *sigfilename);
iobuf_t open_sigfile (const char *sigfilename, progress_filter_context_t *pfx);
void try_make_homedir( const char *fname );
char *get_openpgp_revocdir (const char *home);
@ -374,7 +375,7 @@ void decrypt_messages (ctrl_t ctrl, int nfiles, char *files[]);
/*-- plaintext.c --*/
int hash_datafiles( gcry_md_hd_t md, gcry_md_hd_t md2,
strlist_t files, const char *sigfilename, int textmode );
strlist_t files, const char *sigfilename, int textmode);
int hash_datafile_by_fd ( gcry_md_hd_t md, gcry_md_hd_t md2, int data_fd,
int textmode );
PKT_plaintext *setup_plaintext_name(const char *filename,IOBUF iobuf);