openssl: report errors in OpenSSL error queue when clear it

* ext/openssl/ossl.c (ossl_clear_error): Extracted from
  ossl_make_error(). This prints errors in the OpenSSL error queue if
  OpenSSL.debug is true, and clears the queue.
  (ossl_make_error): use ossl_clear_error().

* ext/openssl/ossl.h: add prototype declaration of ossl_make_error().
  (OSSL_BIO_reset) use ossl_clear_error() to clear the queue. Clearing
  silently makes debugging difficult.

* ext/openssl/ossl_engine.c (ossl_engine_s_by_id): ditto.

* ext/openssl/ossl_ns_spki.c (ossl_spki_initialize): ditto.

* ext/openssl/ossl_pkcs7.c (ossl_pkcs7_verify): ditto.

* ext/openssl/ossl_pkey_dsa.c (ossl_dsa_initialize): ditto.

* ext/openssl/ossl_pkey_ec.c (ossl_ec_key_initialize): ditto.
  (ossl_ec_group_initialize): ditto.

* ext/openssl/ossl_ssl.c (ossl_ssl_shutdown): ditto.

1 files changed, 2 insertions, 2 deletions

diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index 8f6edfab26..a5bddd7d7c 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -213,7 +213,7 @@ static VALUE ossl_ec_key_initialize(int argc, VALUE *argv, VALUE self)
                 const char *name = StringValueCStr(arg);
                 int nid = OBJ_sn2nid(name);
 
-                (void)ERR_get_error();
+		ossl_clear_error(); /* ignore errors in the previous d2i_EC_PUBKEY_bio() */
                 if (nid == NID_undef)
                     ossl_raise(eECError, "unknown curve name (%s)\n", name);
 
@@ -808,7 +808,7 @@ static VALUE ossl_ec_group_initialize(int argc, VALUE *argv, VALUE self)
                 const char *name = StringValueCStr(arg1);
                 int nid = OBJ_sn2nid(name);
 
-		(void)ERR_get_error();
+		ossl_clear_error(); /* ignore errors in d2i_ECPKParameters_bio() */
                 if (nid == NID_undef)
                     ossl_raise(eEC_GROUP, "unknown curve name (%s)", name);