Avoid coredumps for CONF_get_...(NULL, ...)

CHANGES

@@ -4,6 +4,15 @@
 
  Changes between 0.9.6 and 0.9.6a  [xx XXX 2001]
 
+  *) In the NCONF_...-based implementations for CONF_... queries
+     (crypto/conf/conf_lib.c), if the input LHASH is NULL, avoid using
+     a temporary CONF structure with the data component set to NULL
+     (which gives segmentation faults in lh_retrieve).
+     Instead, use NULL for the CONF pointer in CONF_get_string and
+     CONF_get_number (which may use environment variables) and directly
+     return NULL from CONF_get_section.
+     [Bodo Moeller]
+
   *) Tolerate nonRepudiation as being valid for S/MIME signing and certSign
      keyUsage if basicConstraints absent for a CA.
      [Steve Henson]

crypto/conf/conf_lib.c

@@ -130,6 +130,12 @@ LHASH *CONF_load_bio(LHASH *conf, BIO *bp,long *eline)
 	}
 
 STACK_OF(CONF_VALUE) *CONF_get_section(LHASH *conf,char *section)
+	{
+	if (conf == NULL)
+		{
+		return NULL;
+		}
+	else
 		{
 		CONF ctmp;
 
@@ -140,8 +146,15 @@ STACK_OF(CONF_VALUE) *CONF_get_section(LHASH *conf,char *section)
 		ctmp.data = conf;
 		return NCONF_get_section(&ctmp, section);
 		}
+	}
 
 char *CONF_get_string(LHASH *conf,char *group,char *name)
+	{
+	if (conf == NULL)
+		{
+		return NCONF_get_string(NULL, group, name);
+		}
+	else
 		{
 		CONF ctmp;
 
@@ -152,8 +165,15 @@ char *CONF_get_string(LHASH *conf,char *group,char *name)
 		ctmp.data = conf;
 		return NCONF_get_string(&ctmp, group, name);
 		}
+	}
 
 long CONF_get_number(LHASH *conf,char *group,char *name)
+	{
+	if (conf == NULL)
+		{
+		return NCONF_get_number(NULL, group, name);
+		}
+	else
 		{
 		CONF ctmp;
 
@@ -164,6 +184,7 @@ long CONF_get_number(LHASH *conf,char *group,char *name)
 		ctmp.data = conf;
 		return NCONF_get_number(&ctmp, group, name);
 		}
+	}
 
 void CONF_free(LHASH *conf)
 	{