src/core/lib/slice/percent_encoding.h

/*
 *
 * Copyright 2016 gRPC authors.
 *
 * 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.
 *
 */

#ifndef GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H
#define GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H

/* Percent encoding and decoding of slices.
   Transforms arbitrary strings into safe-for-transmission strings by using
   variants of percent encoding (RFC 3986).
   Two major variants are supplied: one that strictly matches URL encoding,
     and another which applies percent encoding only to non-http2 header
     bytes (the 'compatible' variant) */

#include <grpc/support/port_platform.h>

#include <stdbool.h>

#include "absl/types/optional.h"

#include <grpc/slice.h>

namespace grpc_core {

enum class PercentEncodingType {
  // Flags [A-Za-z0-9-_.~] as unreserved bytes for the percent encoding routines
  URL,
  // Flags ascii7 non-control characters excluding '%' as unreserved bytes for
  // the
  // percent encoding routines
  Compatible
};

// Percent-encode a slice, returning the new slice (this cannot fail):
// unreserved_bytes is a bitfield indicating which bytes are considered
// unreserved and thus do not need percent encoding
grpc_slice PercentEncodeSlice(const grpc_slice& slice,
                              PercentEncodingType type);
// Percent-decode a slice, strictly.
// If the input is legal (contains no unreserved bytes, and legal % encodings),
// returns the decoded slice.
// If the input is not legal, returns {}.
absl::optional<grpc_slice> PercentDecodeSlice(const grpc_slice& slice_in,
                                              PercentEncodingType type);
// Percent-decode a slice, permissively.
// If a % triplet can not be decoded, pass it through verbatim.
// This cannot fail.
grpc_slice PermissivePercentDecodeSlice(const grpc_slice& slice_in);

}  // namespace grpc_core

#endif /* GRPC_CORE_LIB_SLICE_PERCENT_ENCODING_H */