Deffer initializing crypto routines in PKCS11 engine until needed

Fixes:OpenSC#456

bind_helper in eng_font.c is split into bind_helper and bind_helper2
The calls to ENGINE_set_RSA, ENGINE_set_EC, ENGINE_set_ECDH and
ENGINE_set_pkey_meths are moved to bind_helper2.

bind_helper2 is called from load_pubkey and load_privkey.

This in effect gets around the problem OpenSSL 3.0.x has when
it loads the pkcs11 engine from openssl.cnf, and then tries to use it
as a default provider even when no engine was specified on
the command line.

 On branch deffer_init_crypto
 Changes to be committed:
	modified:   eng_front.c

src/eng_front.c

@@ -82,6 +82,8 @@ static const ENGINE_CMD_DEFN engine_cmd_defns[] = {
  {0, NULL, NULL, 0}
 };
 
+static int bind_helper2(ENGINE *e);
+
 static ENGINE_CTX *get_ctx(ENGINE *engine)
 {
  ENGINE_CTX *ctx;
@@ -174,6 +176,7 @@ static EVP_PKEY *load_pubkey(ENGINE *engine, const char *s_key_id,
  ctx = get_ctx(engine);
  if (!ctx)
  return 0;
+ bind_helper2(engine);
  return ctx_load_pubkey(ctx, s_key_id, ui_method, callback_data);
 }
 
@@ -186,6 +189,7 @@ static EVP_PKEY *load_privkey(ENGINE *engine, const char *s_key_id,
  ctx = get_ctx(engine);
  if (!ctx)
  return 0;
+ bind_helper2(engine);
  pkey = ctx_load_privkey(ctx, s_key_id, ui_method, callback_data);
 #ifdef EVP_F_EVP_PKEY_SET1_ENGINE
  /* EVP_PKEY_set1_engine() is required for OpenSSL 1.1.x,
@@ -219,6 +223,25 @@ static int bind_helper(ENGINE *e)
  !ENGINE_set_ctrl_function(e, engine_ctrl) ||
  !ENGINE_set_cmd_defns(e, engine_cmd_defns) ||
  !ENGINE_set_name(e, PKCS11_ENGINE_NAME) ||
+
+ !ENGINE_set_load_pubkey_function(e, load_pubkey) ||
+ !ENGINE_set_load_privkey_function(e, load_privkey)) {
+ return 0;
+ } else {
+ ERR_load_ENG_strings();
+ return 1;
+ }
+}
+
+/*
+ * With OpenSSL 3.x, engines might be used because defined in openssl.cnf
+ * which will cause problems
+ * only add engine routines after a call to load keys
+ */
+
+static int bind_helper2(ENGINE *e)
+{
+ if (
 #ifndef OPENSSL_NO_RSA
  !ENGINE_set_RSA(e, PKCS11_get_rsa_method()) ||
 #endif
@@ -235,12 +258,9 @@ static int bind_helper(ENGINE *e)
  !ENGINE_set_ECDH(e, PKCS11_get_ecdh_method()) ||
 #endif
 #endif /* OPENSSL_VERSION_NUMBER */
- !ENGINE_set_pkey_meths(e, PKCS11_pkey_meths) ||
- !ENGINE_set_load_pubkey_function(e, load_pubkey) ||
- !ENGINE_set_load_privkey_function(e, load_privkey)) {
+ !ENGINE_set_pkey_meths(e, PKCS11_pkey_meths)) {
  return 0;
  } else {
- ERR_load_ENG_strings();
  return 1;
  }
 }