| // Copyright 2021 Google 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 "tink/jwt/internal/jwt_mac_impl.h" |
| |
| #include <string> |
| #include <utility> |
| |
| #include "absl/status/status.h" |
| #include "absl/strings/escaping.h" |
| #include "absl/strings/str_split.h" |
| #include "tink/jwt/internal/json_util.h" |
| #include "tink/jwt/internal/jwt_format.h" |
| |
| namespace crypto { |
| namespace tink { |
| namespace jwt_internal { |
| |
| util::StatusOr<std::string> JwtMacImpl::ComputeMacAndEncodeWithKid( |
| const RawJwt& token, absl::optional<absl::string_view> kid) const { |
| absl::optional<std::string> type_header; |
| if (token.HasTypeHeader()) { |
| util::StatusOr<std::string> type = token.GetTypeHeader(); |
| if (!type.ok()) { |
| return type.status(); |
| } |
| type_header = *type; |
| } |
| if (custom_kid_.has_value()) { |
| if (kid.has_value()) { |
| return util::Status(absl::StatusCode::kInvalidArgument, |
| "TINK keys are not allowed to have a kid value set."); |
| } |
| kid = *custom_kid_; |
| } |
| util::StatusOr<std::string> encoded_header = |
| CreateHeader(algorithm_, type_header, kid); |
| if (!encoded_header.ok()) { |
| return encoded_header.status(); |
| } |
| util::StatusOr<std::string> payload = token.GetJsonPayload(); |
| if (!payload.ok()) { |
| return payload.status(); |
| } |
| std::string encoded_payload = EncodePayload(*payload); |
| std::string unsigned_token = |
| absl::StrCat(*encoded_header, ".", encoded_payload); |
| util::StatusOr<std::string> tag = mac_->ComputeMac(unsigned_token); |
| if (!tag.ok()) { |
| return tag.status(); |
| } |
| std::string encoded_tag = EncodeSignature(*tag); |
| return absl::StrCat(unsigned_token, ".", encoded_tag); |
| } |
| |
| util::StatusOr<VerifiedJwt> JwtMacImpl::VerifyMacAndDecodeWithKid( |
| absl::string_view compact, const JwtValidator& validator, |
| absl::optional<absl::string_view> kid) const { |
| std::size_t mac_pos = compact.find_last_of('.'); |
| if (mac_pos == absl::string_view::npos) { |
| return util::Status(absl::StatusCode::kInvalidArgument, "invalid token"); |
| } |
| absl::string_view unsigned_token = compact.substr(0, mac_pos); |
| std::string mac_value; |
| if (!DecodeSignature(compact.substr(mac_pos + 1), &mac_value)) { |
| return util::Status(absl::StatusCode::kInvalidArgument, "invalid JWT MAC"); |
| } |
| util::Status verify_result = mac_->VerifyMac(mac_value, unsigned_token); |
| if (!verify_result.ok()) { |
| // Use a different error code so that we can distinguish it. |
| return util::Status(absl::StatusCode::kUnauthenticated, |
| verify_result.message()); |
| } |
| std::vector<absl::string_view> parts = absl::StrSplit(unsigned_token, '.'); |
| if (parts.size() != 2) { |
| return util::Status( |
| absl::StatusCode::kInvalidArgument, |
| "only tokens in JWS compact serialization format are supported"); |
| } |
| std::string json_header; |
| if (!DecodeHeader(parts[0], &json_header)) { |
| return util::Status(absl::StatusCode::kInvalidArgument, "invalid header"); |
| } |
| util::StatusOr<google::protobuf::Struct> header = |
| JsonStringToProtoStruct(json_header); |
| if (!header.ok()) { |
| return header.status(); |
| } |
| util::Status validate_header_result = |
| ValidateHeader(*header, algorithm_, kid, custom_kid_); |
| if (!validate_header_result.ok()) { |
| return validate_header_result; |
| } |
| std::string json_payload; |
| if (!DecodePayload(parts[1], &json_payload)) { |
| return util::Status(absl::StatusCode::kInvalidArgument, |
| "invalid JWT payload"); |
| } |
| util::StatusOr<RawJwt> raw_jwt = |
| RawJwtParser::FromJson(GetTypeHeader(*header), json_payload); |
| if (!raw_jwt.ok()) { |
| return raw_jwt.status(); |
| } |
| util::Status validate_result = validator.Validate(*raw_jwt); |
| if (!validate_result.ok()) { |
| return validate_result; |
| } |
| return VerifiedJwt(*std::move(raw_jwt)); |
| } |
| |
| } // namespace jwt_internal |
| } // namespace tink |
| } // namespace crypto |