diff --git a/third_party/libuweave/src/macaroon_encoding.h b/third_party/libuweave/src/macaroon_encoding.h
new file mode 100644
index 0000000..2c11fd1
--- /dev/null
+++ b/third_party/libuweave/src/macaroon_encoding.h
@@ -0,0 +1,44 @@
+// Copyright 2015 The Weave Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UW_LIBUWEAVE_SRC_MACAROON_ENCODING_
+#define UW_LIBUWEAVE_SRC_MACAROON_ENCODING_
+
+/*
+ * Utility functions to encode and decode canonical CBOR representations for
+ * cryptographic use, such as signatures. We only need to support a very small
+ * subset of the CBOR standard, since only these are used in our cryptographic
+ * designs. The supported data types are: unsigned integers (maximum 32 bits),
+ * byte strings, and text strings.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+// Get the number of bytes that is occupied by the first data item in the give
+// CBOR string.
+bool uw_macaroon_encoding_get_item_len_(const uint8_t* cbor, size_t cbor_len,
+                                        size_t* first_item_len);
+
+bool uw_macaroon_encoding_encode_uint_(const uint32_t unsigned_int,
+                                       uint8_t* buffer, size_t buffer_size,
+                                       size_t* resulting_cbor_len);
+bool uw_macaroon_encoding_encode_byte_str_(const uint8_t* str, size_t str_len,
+                                           uint8_t* buffer, size_t buffer_size,
+                                           size_t* resulting_cbor_len);
+bool uw_macaroon_encoding_encode_text_str_(const uint8_t* str, size_t str_len,
+                                           uint8_t* buffer, size_t buffer_size,
+                                           size_t* resulting_cbor_len);
+
+bool uw_macaroon_encoding_decode_uint_(const uint8_t* cbor, size_t cbor_len,
+                                       uint32_t* unsigned_int);
+bool uw_macaroon_encoding_decode_byte_str_(const uint8_t* cbor, size_t cbor_len,
+                                           const uint8_t** str,
+                                           size_t* str_len);
+bool uw_macaroon_encoding_decode_text_str_(const uint8_t* cbor, size_t cbor_len,
+                                           const uint8_t** str,
+                                           size_t* str_len);
+
+#endif  // UW_LIBUWEAVE_SRC_MACAROON_ENCODING_