Subject: Sss: use BN_set_word(x, 0) instead of BN_zero()
Origin: v18-2-gee1dfed <https://github.com/latchset/clevis/commit/v18-2-gee1dfed>
Upstream-Author: Sergio Correia <scorreia@redhat.com>
Date: Mon May 3 22:36:36 2021 -0300

    Different OpenSSL versions define BN_zero() differently -- sometimes
    returning an integer, sometimes as void --, so let's use instead
    BN_set_word() instead, not to have issues when building with these
    different versions.

--- a/src/pins/sss/sss.c
+++ b/src/pins/sss/sss.c
@@ -214,7 +214,7 @@
     if (BN_rand_range(xx, pp) <= 0)
         return NULL;
 
-    if (BN_zero(yy) <= 0)
+    if (BN_set_word(yy, 0) <= 0)
         return NULL;
 
     for (size_t i = 0; i < json_array_size(e); i++) {
@@ -272,7 +272,7 @@
     if (!ctx || !pp || !acc || !tmp || !k)
         return NULL;
 
-    if (BN_zero(k) <= 0)
+    if (BN_set_word(k, 0) <= 0)
         return NULL;
 
     len = jose_b64_dec(p, NULL, 0);
@@ -303,7 +303,7 @@
 
             /* acc *= (0 - xi) / (xo - xi) */
 
-            if (BN_zero(tmp) <= 0)
+            if (BN_set_word(tmp, 0) <= 0)
                 return NULL;
 
             if (BN_mod_sub(tmp, tmp, xi, pp, ctx) <= 0)