Re: [PATCH v2] ima-evm-utils: rework openssl init

[Vitaly Chikunov <vt@altlinux.org>]

Mimi,

On Mon, Mar 11, 2019 at 02:15:49AM +0300, Vitaly Chikunov wrote:
> On Sun, Mar 10, 2019 at 06:32:02PM -0400, Mimi Zohar wrote:
> > 
> > On Sun, 2019-02-03 at 20:47 +0300, Vitaly Chikunov wrote:
> > > Remove deprecated call to OpenSSL_add_all_algorithms().
> > > Allow to disable openssl config loading via configure
> > > `--disable-openssl-conf' option.
> > > Finish engine initialization properly by calling ENGINE_set_default(),
> > > as suggested by James Bottomley.
> > > 
> > 
> > Thanks, could you also display the status under "Give some feedback".
> 
> OK.
> 
> > 
> > Mimi
> > 
> > 
> > > Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
> > > ---
> > > - v1 is "ima-evm-utils: remove redundant call to OpenSSL_add_all_algorithms"
> > > - everything is changed as suggested in mailing list, not just
> > >   redundant OpenSSL_add_all_algorithms() call is removed.
> > > 
> > >  configure.ac    | 6 ++++++
> > >  src/evmctl.c    | 1 +
> > >  src/libimaevm.c | 8 ++++++--
> > >  3 files changed, 13 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/configure.ac b/configure.ac
> > > index 60f3684..ff8ac29 100644
> > > --- a/configure.ac
> > > +++ b/configure.ac
> > > @@ -39,6 +39,12 @@ AC_ARG_WITH(kernel_headers, [AS_HELP_STRING([--with-kernel-headers=PATH],
> > >  	    [KERNEL_HEADERS="$withval"],
> > >  	    [KERNEL_HEADERS=/lib/modules/$(uname -r)/source])
> > > 
> > > +AC_ARG_ENABLE([openssl_conf],
> > > +	      [AS_HELP_STRING([--disable-openssl-conf], [disable loading of openssl config by libimaevm])],
> > > +	      if test "$enable_openssl_conf" = "no"; then
> > > +		AC_DEFINE(DISABLE_OPENSSL_CONF, 1, [Define to disable loading of openssl config by libimaevm.])
> > > +	      fi)
> > > +
> > >  #debug support - yes for a while
> > >  PKG_ARG_ENABLE(debug, "yes", DEBUG, [Enable Debug support])
> > >  if test $pkg_cv_enable_debug = yes; then
> > > diff --git a/src/evmctl.c b/src/evmctl.c
> > > index 2e4d551..fa074c4 100644
> > > --- a/src/evmctl.c
> > > +++ b/src/evmctl.c
> > > @@ -1904,6 +1904,7 @@ int main(int argc, char *argv[])
> > >  				ENGINE_free(eng);
> > >  				eng = NULL;
> > >  			}
> > > +			ENGINE_set_default(eng, ENGINE_METHOD_ALL);
> > >  			break;
> > >  		case 140: /* --xattr-user */
> > >  			xattr_ima = "user.ima";
> > > diff --git a/src/libimaevm.c b/src/libimaevm.c
> > > index 799eeec..db27c6f 100644
> > > --- a/src/libimaevm.c
> > > +++ b/src/libimaevm.c
> > > @@ -976,7 +976,11 @@ int sign_hash(const char *hashalgo, const unsigned char *hash, int size, const c
> > > 
> > >  static void libinit()
> > >  {
> > > -	OpenSSL_add_all_algorithms();
> > > -	OPENSSL_add_all_algorithms_conf();
> > > +	OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS |
> > > +			    OPENSSL_INIT_ADD_ALL_DIGESTS |
> > > +#ifndef DISABLE_OPENSSL_CONF
> > > +			    OPENSSL_INIT_LOAD_CONFIG |
> > > +#endif
> > > +			    OPENSSL_INIT_ENGINE_ALL_BUILTIN, NULL);

I think now, that libimaevm should not load config, because it is
library and that decision should be of the program that uses it.

Thus, src/libimaevm.c:libinit should only call 

      OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS |
			  OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);

(like OpenSSL_add_all_algorithms*() was doing) and option
`--disable-openssl-conf` should be removed.

But, evmctl should always call OPENSSL_init_crypto() again, with
`OPENSSL_INIT_LOAD_CONFIG | OPENSSL_INIT_ENGINE_ALL_BUILTIN`.

What do you think?

If you wish we can repurpose `--disable-openssl-conf` to affect `evmctl`
instead of `libimaevm`.

Thanks,