--- a/openslp/common/slp_crypto.c
+++ b/openslp/common/slp_crypto.c
@@ -53,6 +53,80 @@
 #include "slp_crypto.h"
 #include "slp_message.h"
   
+/* 1.1.0 -> 1.0.x compatibility layer
+ * See https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes#Compatibility_Layer
+ * for details and additiona compatibility routines if needed in the future.
+ */
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+static void DSA_get0_pqg(const DSA *d, const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
+{
+    if (p != NULL)
+        *p = d->p;
+    if (q != NULL)
+        *q = d->q;
+    if (g != NULL)
+        *g = d->g;
+}
+
+static int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
+{
+    /* If the fields p, q and g in d are NULL, the corresponding input
+     * parameters MUST be non-NULL.
+     */
+    if ((d->p == NULL && p == NULL)
+            || (d->q == NULL && q == NULL) 
+            || (d->g == NULL && g == NULL))
+        return 0;
+
+    if (p != NULL)
+    {
+        BN_free(d->p);
+        d->p = p;
+    }
+    if (q != NULL)
+    {
+        BN_free(d->q);
+        d->q = q;
+    }
+    if (g != NULL)
+    {
+        BN_free(d->g);
+        d->g = g;
+    }
+    return 1;
+}
+
+static void DSA_get0_key(const DSA *d, const BIGNUM **pub_key, const BIGNUM **priv_key)
+{
+    if (pub_key != NULL)
+        *pub_key = d->pub_key;
+    if (priv_key != NULL)
+        *priv_key = d->priv_key;
+}
+
+static int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
+{
+    /* If the field pub_key in d is NULL, the corresponding input
+     * parameters MUST be non-NULL.  The priv_key field may
+     * be left NULL.
+     */
+    if (d->pub_key == NULL && pub_key == NULL)
+        return 0;
+
+    if (pub_key != NULL)
+    {
+        BN_free(d->pub_key);
+        d->pub_key = pub_key;
+    }
+    if (priv_key != NULL)
+    {
+        BN_free(d->priv_key);
+        d->priv_key = priv_key;
+    }
+    return 1;
+}
+#endif
+
 /** Generate a SHA1 digest for the specified block data.
  *
  * @param[in] data - The data block to be hashed.
@@ -88,11 +162,17 @@
    result =  DSA_new();
    if (result)
    {
-      result->p = BN_dup(dsa->p);
-      result->q = BN_dup(dsa->q);
-      result->g = BN_dup(dsa->g);
-      result->priv_key = BN_dup(dsa->priv_key);
-      result->pub_key = BN_dup(dsa->pub_key);
+      const BIGNUM *p, *q, *g;
+      const BIGNUM *priv_key, *pub_key;
+
+      DSA_get0_pqg(dsa, &p, &q, &g);
+      DSA_get0_key(dsa, &pub_key, &priv_key);
+
+      /* would be nice to check return values,
+       * but original code didn't do that either...
+       */
+      DSA_set0_pqg(result, BN_dup(p), BN_dup(q), BN_dup(g));
+      DSA_set0_key(result, BN_dup(pub_key), BN_dup(priv_key));
    }
    return result;
 }