More configurable crypto and ssl library initialization

1.  In addition to overriding the default application name,
    one can now also override the configuration file name
    and flags passed to CONF_modules_load_file().

2.  By default we still keep going when configuration file
    processing fails.  But, applications that want to be strict
    about initialization errors can now make explicit flag
    choices via non-null OPENSSL_INIT_SETTINGS that omit the
    CONF_MFLAGS_IGNORE_RETURN_CODES flag (which had so far been
    both undocumented and unused).

3.  In OPENSSL_init_ssl() do not request OPENSSL_INIT_LOAD_CONFIG
    if the options already include OPENSSL_INIT_NO_LOAD_CONFIG.

4.  Don't set up atexit() handlers when called with INIT_BASE_ONLY.

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7986)

1 files changed, 12 insertions, 0 deletions

diff --git a/crypto/err/err.c b/crypto/err/err.c
index c80aa6b..44e7115 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -741,6 +741,18 @@ int err_shelve_state(void **state)
 {
     int saveerrno = get_last_sys_error();
 
+    /*
+     * Note, at present our only caller is OPENSSL_init_crypto(), indirectly
+     * via ossl_init_load_crypto_nodelete(), by which point the requested
+     * "base" initialization has already been performed, so the below call is a
+     * NOOP, that re-enters OPENSSL_init_crypto() only to quickly return.
+     *
+     * If are no other valid callers of this function, the call below can be
+     * removed, avoiding the re-entry into OPENSSL_init_crypto().  If there are
+     * potential uses that are not from inside OPENSSL_init_crypto(), then this
+     * call is needed, but some care is required to make sure that the re-entry
+     * remains a NOOP.
+     */
     if (!OPENSSL_init_crypto(OPENSSL_INIT_BASE_ONLY, NULL))
         return 0;