1 files changed, 90 insertions, 0 deletions
diff --git a/src/plugins/wireguard/wireguard_hchacha20.h b/src/plugins/wireguard/wireguard_hchacha20.h
new file mode 100644
index 00000000000..a2d139621c9
--- /dev/null
+++ b/src/plugins/wireguard/wireguard_hchacha20.h
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2022 Rubicon Communications, LLC.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * chacha-merged.c version 20080118
+ * D. J. Bernstein
+ * Public domain.
+ */
+
+#ifndef __included_wg_hchacha20_h__
+#define __included_wg_hchacha20_h__
+
+#include <vlib/vlib.h>
+
+/* clang-format off */
+#define U32C(v) (v##U)
+#define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF))
+
+#define ROTL32(v, n) \
+  (U32V((v) << (n)) | ((v) >> (32 - (n))))
+
+#define U8TO32_LITTLE(p) \
+  (((u32)((p)[0])      ) | \
+   ((u32)((p)[1]) <<  8) | \
+   ((u32)((p)[2]) << 16) | \
+   ((u32)((p)[3]) << 24))
+
+#define ROTATE(v,c) (ROTL32(v,c))
+#define XOR(v,w) ((v) ^ (w))
+#define PLUS(v,w) (U32V((v) + (w)))
+
+#define QUARTERROUND(a,b,c,d) \
+  a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \
+  c = PLUS(c,d); b = ROTATE(XOR(b,c),12); \
+  a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \
+  c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);
+/* clang-format on */
+
+static const char sigma[16] = "expand 32-byte k";
+
+static inline void
+hchacha20 (u32 derived_key[8], const u8 nonce[16], const u8 key[32])
+{
+  int i;
+  u32 x[] = { U8TO32_LITTLE (sigma + 0), U8TO32_LITTLE (sigma + 4),
+	      U8TO32_LITTLE (sigma + 8), U8TO32_LITTLE (sigma + 12),
+	      U8TO32_LITTLE (key + 0),	 U8TO32_LITTLE (key + 4),
+	      U8TO32_LITTLE (key + 8),	 U8TO32_LITTLE (key + 12),
+	      U8TO32_LITTLE (key + 16),	 U8TO32_LITTLE (key + 20),
+	      U8TO32_LITTLE (key + 24),	 U8TO32_LITTLE (key + 28),
+	      U8TO32_LITTLE (nonce + 0), U8TO32_LITTLE (nonce + 4),
+	      U8TO32_LITTLE (nonce + 8), U8TO32_LITTLE (nonce + 12) };
+
+  for (i = 20; i > 0; i -= 2)
+    {
+      QUARTERROUND (x[0], x[4], x[8], x[12])
+      QUARTERROUND (x[1], x[5], x[9], x[13])
+      QUARTERROUND (x[2], x[6], x[10], x[14])
+      QUARTERROUND (x[3], x[7], x[11], x[15])
+      QUARTERROUND (x[0], x[5], x[10], x[15])
+      QUARTERROUND (x[1], x[6], x[11], x[12])
+      QUARTERROUND (x[2], x[7], x[8], x[13])
+      QUARTERROUND (x[3], x[4], x[9], x[14])
+    }
+
+  clib_memcpy (derived_key + 0, x + 0, sizeof (u32) * 4);
+  clib_memcpy (derived_key + 4, x + 12, sizeof (u32) * 4);
+}
+
+#endif /* __included_wg_hchacha20_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */