revert BN_CTX_init stub for older applications

src/ssl_bn.c

@@ -2382,6 +2382,27 @@ WOLFSSL_BN_CTX* wolfSSL_BN_CTX_new(void)
     return ctx;
 }
 
+
+#ifndef NO_WOLFSSL_STUB
+/* deprecated
+ *
+ * Initialize a BN context object.
+ * This function was removed in OpenSSL 1.1.0 and later.
+ * Keeping a stub function here for older applications that have BN_CTX_init()
+ * calls.
+ *
+ * @param [in] ctx  Dummy BN context.
+ */
+void wolfSSL_BN_CTX_init(WOLFSSL_BN_CTX* ctx)
+{
+    (void)ctx;
+    WOLFSSL_ENTER("wolfSSL_BN_CTX_init");
+    WOLFSSL_STUB("wolfSSL_BN_CTX_init");
+    WOLFSSL_MSG("wolfSSL_BN_CTX_init is deprecated");
+}
+#endif
+
+
 /* Free a BN context object.
  *
  * @param [in] ctx  BN context object.

tests/api.c

@@ -28725,6 +28725,9 @@ static int test_wolfSSL_BN_CTX(void)
 
     ExpectNotNull(bn_ctx = BN_CTX_new());
 
+    /* No implementation. */
+    BN_CTX_init(NULL);
+
     ExpectNull(BN_CTX_get(NULL));
     ExpectNotNull(BN_CTX_get(bn_ctx));
     ExpectNotNull(BN_CTX_get(bn_ctx));

wolfssl/openssl/bn.h

@@ -88,6 +88,7 @@ typedef struct WOLFSSL_BN_MONT_CTX WOLFSSL_BN_MONT_CTX;
 typedef struct WOLFSSL_BN_GENCB    WOLFSSL_BN_GENCB;
 
 WOLFSSL_API WOLFSSL_BN_CTX* wolfSSL_BN_CTX_new(void);
+WOLFSSL_API void           wolfSSL_BN_CTX_init(WOLFSSL_BN_CTX* ctx);
 WOLFSSL_API void           wolfSSL_BN_CTX_free(WOLFSSL_BN_CTX* ctx);
 
 WOLFSSL_API WOLFSSL_BIGNUM* wolfSSL_BN_new(void);