chore: checkpoint before Python removal

vendor/aws-lc-sys/aws-lc/crypto/fipsmodule/modes/ofb.c

@@ -0,0 +1,45 @@
+// Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+#include <openssl/type_check.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include "internal.h"
+
+
+OPENSSL_STATIC_ASSERT(16 % sizeof(size_t) == 0,
+                      ofb_block_cannot_be_divided_into_size_t)
+
+void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
+                           const AES_KEY *key, uint8_t ivec[16], unsigned *num,
+                           block128_f block) {
+  assert(key != NULL && ivec != NULL && num != NULL);
+  assert(len == 0 || (in != NULL && out != NULL));
+
+  unsigned n = *num;
+
+  while (n && len) {
+    *(out++) = *(in++) ^ ivec[n];
+    --len;
+    n = (n + 1) % 16;
+  }
+
+  while (len >= 16) {
+    (*block)(ivec, ivec, key);
+    CRYPTO_xor16(out, in, ivec);
+    len -= 16;
+    out += 16;
+    in += 16;
+    n = 0;
+  }
+  if (len) {
+    (*block)(ivec, ivec, key);
+    while (len--) {
+      out[n] = in[n] ^ ivec[n];
+      ++n;
+    }
+  }
+  *num = n;
+}