| /* |
| * |
| * 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. |
| * |
| */ |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include "src/core/lib/slice/percent_encoding.h" |
| |
| #include <cstdint> |
| |
| #include <grpc/support/log.h> |
| |
| #include "src/core/lib/gprpp/bitset.h" |
| #include "src/core/lib/slice/slice_internal.h" |
| |
| #if __cplusplus > 201103l |
| #define GRPC_PCTENCODE_CONSTEXPR_FN constexpr |
| #define GRPC_PCTENCODE_CONSTEXPR_VALUE constexpr |
| #else |
| #define GRPC_PCTENCODE_CONSTEXPR_FN |
| #define GRPC_PCTENCODE_CONSTEXPR_VALUE const |
| #endif |
| |
| namespace grpc_core { |
| |
| namespace { |
| class UrlTable : public BitSet<256> { |
| public: |
| GRPC_PCTENCODE_CONSTEXPR_FN UrlTable() { |
| for (int i = 'a'; i <= 'z'; i++) set(i); |
| for (int i = 'A'; i <= 'Z'; i++) set(i); |
| for (int i = '0'; i <= '9'; i++) set(i); |
| set('-'); |
| set('_'); |
| set('.'); |
| set('~'); |
| } |
| }; |
| |
| GRPC_PCTENCODE_CONSTEXPR_VALUE UrlTable g_url_table; |
| |
| class CompatibleTable : public BitSet<256> { |
| public: |
| GRPC_PCTENCODE_CONSTEXPR_FN CompatibleTable() { |
| for (int i = 32; i <= 126; i++) { |
| if (i == '%') continue; |
| set(i); |
| } |
| } |
| }; |
| |
| GRPC_PCTENCODE_CONSTEXPR_VALUE CompatibleTable g_compatible_table; |
| |
| // Map PercentEncodingType to a lookup table of legal symbols for that encoding. |
| const BitSet<256>& LookupTableForPercentEncodingType(PercentEncodingType type) { |
| switch (type) { |
| case PercentEncodingType::URL: |
| return g_url_table; |
| case PercentEncodingType::Compatible: |
| return g_compatible_table; |
| } |
| // Crash if a bad PercentEncodingType was passed in. |
| GPR_UNREACHABLE_CODE(abort()); |
| } |
| } // namespace |
| |
| grpc_slice PercentEncodeSlice(const grpc_slice& slice, |
| PercentEncodingType type) { |
| static const uint8_t hex[] = "0123456789ABCDEF"; |
| |
| const BitSet<256>& lut = LookupTableForPercentEncodingType(type); |
| |
| // first pass: count the number of bytes needed to output this string |
| size_t output_length = 0; |
| const uint8_t* slice_start = GRPC_SLICE_START_PTR(slice); |
| const uint8_t* slice_end = GRPC_SLICE_END_PTR(slice); |
| const uint8_t* p; |
| bool any_reserved_bytes = false; |
| for (p = slice_start; p < slice_end; p++) { |
| bool unres = lut.is_set(*p); |
| output_length += unres ? 1 : 3; |
| any_reserved_bytes |= !unres; |
| } |
| // no unreserved bytes: return the string unmodified |
| if (!any_reserved_bytes) { |
| return grpc_slice_ref_internal(slice); |
| } |
| // second pass: actually encode |
| grpc_slice out = GRPC_SLICE_MALLOC(output_length); |
| uint8_t* q = GRPC_SLICE_START_PTR(out); |
| for (p = slice_start; p < slice_end; p++) { |
| if (lut.is_set(*p)) { |
| *q++ = *p; |
| } else { |
| *q++ = '%'; |
| *q++ = hex[*p >> 4]; |
| *q++ = hex[*p & 15]; |
| } |
| } |
| GPR_ASSERT(q == GRPC_SLICE_END_PTR(out)); |
| return out; |
| } |
| |
| static bool valid_hex(const uint8_t* p, const uint8_t* end) { |
| if (p >= end) return false; |
| return (*p >= '0' && *p <= '9') || (*p >= 'a' && *p <= 'f') || |
| (*p >= 'A' && *p <= 'F'); |
| } |
| |
| static uint8_t dehex(uint8_t c) { |
| if (c >= '0' && c <= '9') return static_cast<uint8_t>(c - '0'); |
| if (c >= 'A' && c <= 'F') return static_cast<uint8_t>(c - 'A' + 10); |
| if (c >= 'a' && c <= 'f') return static_cast<uint8_t>(c - 'a' + 10); |
| GPR_UNREACHABLE_CODE(return 255); |
| } |
| |
| absl::optional<grpc_slice> PercentDecodeSlice(const grpc_slice& slice_in, |
| PercentEncodingType type) { |
| const uint8_t* p = GRPC_SLICE_START_PTR(slice_in); |
| const uint8_t* in_end = GRPC_SLICE_END_PTR(slice_in); |
| size_t out_length = 0; |
| bool any_percent_encoded_stuff = false; |
| const BitSet<256>& lut = LookupTableForPercentEncodingType(type); |
| while (p != in_end) { |
| if (*p == '%') { |
| if (!valid_hex(++p, in_end)) return {}; |
| if (!valid_hex(++p, in_end)) return {}; |
| p++; |
| out_length++; |
| any_percent_encoded_stuff = true; |
| } else if (lut.is_set(*p)) { |
| p++; |
| out_length++; |
| } else { |
| return {}; |
| } |
| } |
| if (!any_percent_encoded_stuff) { |
| return grpc_slice_ref_internal(slice_in); |
| } |
| p = GRPC_SLICE_START_PTR(slice_in); |
| grpc_slice slice_out = GRPC_SLICE_MALLOC(out_length); |
| uint8_t* q = GRPC_SLICE_START_PTR(slice_out); |
| while (p != in_end) { |
| if (*p == '%') { |
| *q++ = static_cast<uint8_t>(dehex(p[1]) << 4) | (dehex(p[2])); |
| p += 3; |
| } else { |
| *q++ = *p++; |
| } |
| } |
| GPR_ASSERT(q == GRPC_SLICE_END_PTR(slice_out)); |
| return slice_out; |
| } |
| |
| grpc_slice PermissivePercentDecodeSlice(const grpc_slice& slice_in) { |
| const uint8_t* p = GRPC_SLICE_START_PTR(slice_in); |
| const uint8_t* in_end = GRPC_SLICE_END_PTR(slice_in); |
| size_t out_length = 0; |
| bool any_percent_encoded_stuff = false; |
| while (p != in_end) { |
| if (*p == '%') { |
| if (!valid_hex(p + 1, in_end) || !valid_hex(p + 2, in_end)) { |
| p++; |
| out_length++; |
| } else { |
| p += 3; |
| out_length++; |
| any_percent_encoded_stuff = true; |
| } |
| } else { |
| p++; |
| out_length++; |
| } |
| } |
| if (!any_percent_encoded_stuff) { |
| return grpc_slice_ref_internal(slice_in); |
| } |
| p = GRPC_SLICE_START_PTR(slice_in); |
| grpc_slice out = GRPC_SLICE_MALLOC(out_length); |
| uint8_t* q = GRPC_SLICE_START_PTR(out); |
| while (p != in_end) { |
| if (*p == '%') { |
| if (!valid_hex(p + 1, in_end) || !valid_hex(p + 2, in_end)) { |
| *q++ = *p++; |
| } else { |
| *q++ = static_cast<uint8_t>(dehex(p[1]) << 4) | (dehex(p[2])); |
| p += 3; |
| } |
| } else { |
| *q++ = *p++; |
| } |
| } |
| GPR_ASSERT(q == GRPC_SLICE_END_PTR(out)); |
| return out; |
| } |
| |
| } // namespace grpc_core |