On Fri, Aug 20, 2021 at 12:42:26AM +0300, Vitaly Chikunov wrote:

On Thu, Aug 19, 2021 at 05:11:36AM +0300, Vitaly Chikunov wrote:

quoted

After CRYPTO_secure_malloc_init OpenSSL will store private keys in
secure heap. This facility is only available since OpenSSL_1_1_0-pre1.

Signed-off-by: Vitaly Chikunov <redacted>
---
Change from v1:
- Do not use setfbuf to disable buffering as this is not proven to be
  meaningful.
- Use secure heap for passwords too as suggested by Mimi Zohar.
- Fallback to OPENSSL_malloc for old OpenSSL as suggested by Mimi Zohar.
- Simplify logic of calling CRYPTO_secure_malloc_init (call it always on
  OpenSSL init.)
- Should be applied after Bruno Meneguele's "evmctl: fix memory leak in
  get_password" patch v2.

 src/evmctl.c | 143 ++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 118 insertions(+), 25 deletions(-)

@@ -2596,15 +2637,41 @@ static struct option opts[] = {
 
 };
 
+/*
+ * Copy password from optarg into secure heap, so it could be
+ * freed in the same way as a result of get_password().
+ */
+static char *optarg_password(char *optarg)
+{
+	size_t len;
+	char *keypass;
+
+	if (!optarg)
+		return NULL;
+	len = strlen(optarg);
+	keypass = OPENSSL_secure_malloc(len + 1);
+	if (keypass)
+		memcpy(keypass, optarg, len + 1);
+	else
+		perror("OPENSSL_secure_malloc");

I also realized that OPENSSL_secure_malloc does not (intentionally)
set errno, so using perror is perhaps wrong. Better method should be
thanked out.

After some more thinking I think all this perror usage should be
replaced with log_err like in all other places. (perror is used only in
get_password). Log_err hypothetically could log to stdout or to syslog
depending on USE_FPRINTF(*), but perror will always log to stderr.

  (*) Which is _always_ defined though. This is obscure.

Thanks,