chore: checkpoint before Python removal

vendor/aws-lc-sys/aws-lc/crypto/decrepit/dh/dh_decrepit.c

@@ -0,0 +1,54 @@
+// Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+ 
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+
+
+struct wrapped_callback {
+  void (*callback)(int, int, void *);
+  void *arg;
+};
+
+// callback_wrapper converts an “old” style generation callback to the newer
+// |BN_GENCB| form.
+static int callback_wrapper(int event, int n, BN_GENCB *gencb) {
+  struct wrapped_callback *wrapped = (struct wrapped_callback *) gencb->arg;
+  wrapped->callback(event, n, wrapped->arg);
+  return 1;
+}
+
+DH *DH_generate_parameters(int prime_len, int generator,
+                           void (*callback)(int, int, void *), void *cb_arg) {
+  if (prime_len < 0 || generator < 0) {
+      return NULL;
+  }
+
+  DH *ret = DH_new();
+  if (ret == NULL) {
+      return NULL;
+  }
+
+  BN_GENCB gencb_storage;
+  BN_GENCB *cb = NULL;
+
+  struct wrapped_callback wrapped;
+
+  if (callback != NULL) {
+    wrapped.callback = callback;
+    wrapped.arg = cb_arg;
+
+    cb = &gencb_storage;
+    BN_GENCB_set(cb, callback_wrapper, &wrapped);
+  }
+
+  if (!DH_generate_parameters_ex(ret, prime_len, generator, cb)) {
+    goto err;
+  }
+
+  return ret;
+
+err:
+  DH_free(ret);
+  return NULL;
+}