On Wed, 2021-08-25 at 21:41 +0300, Vitaly Chikunov wrote:

Mimi,

On Wed, Aug 25, 2021 at 07:39:30AM -0400, Mimi Zohar wrote:

quoted

Hi Vitaly,

On Sun, 2021-08-22 at 03:10 +0300, Vitaly Chikunov wrote:

quoted

After CRYPTO_secure_malloc_init OpenSSL will store private keys 

^and passwords

No, it meant openssl automatically will handle private keys (and other
internal private data) in secure heap.

Handling of passwords in openssl's secure heap we do ourselves. I can
extend commit message about this.

Ah, nice!   Please expand the patch description, adding what you said
here.

Also, you might want to include that since OPENSSL_secure_malloc_init()
is called from evmctl.c, any application linking with libimaevm would
not be using secure heap.

quoted

quoted

in
secure heap. This facility is only available since OpenSSL_1_1_0-pre1.

Signed-off-by: Vitaly Chikunov <redacted>

Initially we started out discussing ways of protecting passwords, which
this patch does.  Thank you!  I'm not sure, however, it is protecting
the private keys.  Does read_priv_pkey()  also use the secure heap or
is PEM_read_PrivateKey() already safe?

After CRYPTO_secure_malloc_init call all openssl API functions that
handle private keys and passwords should use secure heap. So, in that
regard we don't need to add anything.

Ok

quoted

quoted

---
 src/evmctl.c | 148 +++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 121 insertions(+), 27 deletions(-)

diff --git a/src/evmctl.c b/src/evmctl.c

@@ -188,7 +207,9 @@ static int bin2file(const char *file, const char *ext, const unsigned char *data
 	return err;
 }

-static unsigned char *file2bin(const char *file, const char *ext, int *size)
+/* Return data in OpenSSL secure heap if 'secure' is true. */
+static unsigned char *file2bin(const char *file, const char *ext, int *size,
+			       int secure)
 {

The only caller of file2bin() that sets "secure" is evm_calc_hmac(),
but evm_calc_hmac() is a debugging tool, not meant for setting the real
security.evm xattr.

I can undo file2bin change if you wish, but for uniformity I would have
it changed. We can add comment that it is handling only test & debugging
data, thus not using security measures. May also output some warning at
runtime.

Either way is fine, but somehow please document it.

thanks,

Mimi