1 files changed, 103 insertions, 0 deletions
diff --git a/src/plugins/wireguard/wireguard_chachapoly.c b/src/plugins/wireguard/wireguard_chachapoly.c
new file mode 100644
index 00000000000..961b43f100d
--- /dev/null
+++ b/src/plugins/wireguard/wireguard_chachapoly.c
@@ -0,0 +1,103 @@
+/*
+ * 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.
+ */
+
+#include <wireguard/wireguard.h>
+#include <wireguard/wireguard_chachapoly.h>
+#include <wireguard/wireguard_hchacha20.h>
+
+bool
+wg_chacha20poly1305_calc (vlib_main_t *vm, u8 *src, u32 src_len, u8 *dst,
+			  u8 *aad, u32 aad_len, u64 nonce,
+			  vnet_crypto_op_id_t op_id,
+			  vnet_crypto_key_index_t key_index)
+{
+  vnet_crypto_op_t _op, *op = &_op;
+  u8 iv[12];
+  u8 tag_[NOISE_AUTHTAG_LEN] = {};
+  u8 src_[] = {};
+
+  clib_memset (iv, 0, 12);
+  clib_memcpy (iv + 4, &nonce, sizeof (nonce));
+
+  vnet_crypto_op_init (op, op_id);
+
+  op->tag_len = NOISE_AUTHTAG_LEN;
+  if (op_id == VNET_CRYPTO_OP_CHACHA20_POLY1305_DEC)
+    {
+      op->tag = src + src_len - NOISE_AUTHTAG_LEN;
+      src_len -= NOISE_AUTHTAG_LEN;
+      op->flags |= VNET_CRYPTO_OP_FLAG_HMAC_CHECK;
+    }
+  else
+    op->tag = tag_;
+
+  op->src = !src ? src_ : src;
+  op->len = src_len;
+
+  op->dst = dst;
+  op->key_index = key_index;
+  op->aad = aad;
+  op->aad_len = aad_len;
+  op->iv = iv;
+
+  vnet_crypto_process_ops (vm, op, 1);
+  if (op_id == VNET_CRYPTO_OP_CHACHA20_POLY1305_ENC)
+    {
+      clib_memcpy (dst + src_len, op->tag, NOISE_AUTHTAG_LEN);
+    }
+
+  return (op->status == VNET_CRYPTO_OP_STATUS_COMPLETED);
+}
+
+bool
+wg_xchacha20poly1305_decrypt (vlib_main_t *vm, u8 *src, u32 src_len, u8 *dst,
+			      u8 *aad, u32 aad_len,
+			      u8 nonce[XCHACHA20POLY1305_NONCE_SIZE],
+			      u8 key[CHACHA20POLY1305_KEY_SIZE])
+{
+  int ret, i;
+  u32 derived_key[CHACHA20POLY1305_KEY_SIZE / sizeof (u32)];
+  u64 h_nonce;
+
+  clib_memcpy (&h_nonce, nonce + 16, sizeof (h_nonce));
+  h_nonce = le64toh (h_nonce);
+  hchacha20 (derived_key, nonce, key);
+
+  for (i = 0; i < (sizeof (derived_key) / sizeof (derived_key[0])); i++)
+    (derived_key[i]) = htole32 ((derived_key[i]));
+
+  uint32_t key_idx;
+
+  key_idx =
+    vnet_crypto_key_add (vm, VNET_CRYPTO_ALG_CHACHA20_POLY1305,
+			 (uint8_t *) derived_key, CHACHA20POLY1305_KEY_SIZE);
+
+  ret =
+    wg_chacha20poly1305_calc (vm, src, src_len, dst, aad, aad_len, h_nonce,
+			      VNET_CRYPTO_OP_CHACHA20_POLY1305_DEC, key_idx);
+
+  vnet_crypto_key_del (vm, key_idx);
+  wg_secure_zero_memory (derived_key, CHACHA20POLY1305_KEY_SIZE);
+
+  return ret;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */