| // Copyright 2017 The Chromium Authors. All rights reserved. |
| // Copyright (C) 2018 Apple Inc. All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #pragma once |
| |
| #if ENABLE(WEB_AUTHN) |
| |
| #include "CBORValue.h" |
| #include <stddef.h> |
| |
| // Concise Binary Object Representation (CBOR) decoder as defined by |
| // https://tools.ietf.org/html/rfc7049. This decoder only accepts canonical |
| // CBOR as defined by section 3.9. |
| // Supported: |
| // * Major types: |
| // * 0: Unsigned integers, up to 64-bit. |
| // * 2: Byte strings. |
| // * 3: UTF-8 strings. |
| // * 4: Definite-length arrays. |
| // * 5: Definite-length maps. |
| // * 7: Simple values. |
| // |
| // Requirements for canonical CBOR representation: |
| // - Duplicate keys for map are not allowed. |
| // - Keys for map must be sorted first by length and then by byte-wise |
| // lexical order. |
| // |
| // Known limitations and interpretations of the RFC: |
| // - Does not support negative integers, indefinite data streams and tagging. |
| // - Floating point representations and BREAK stop code in major |
| // type 7 are not supported. |
| // - Non-character codepoint are not supported for Major type 3. |
| // - Incomplete CBOR data items are treated as syntax errors. |
| // - Trailing data bytes are treated as errors. |
| // - Unknown additional information formats are treated as syntax errors. |
| // - Callers can decode CBOR values with at most 16 nested depth layer. More |
| // strict restrictions on nesting layer size of CBOR values can be enforced |
| // by setting |maxNestingLevel|. |
| // - Only CBOR maps with integer or string type keys are supported due to the |
| // cost of serialization when sorting map keys. |
| // - Simple values that are unassigned/reserved as per RFC 7049 are not |
| // supported and treated as errors. |
| |
| namespace cbor { |
| |
| class CBORReader { |
| WTF_MAKE_NONCOPYABLE(CBORReader); |
| public: |
| using Bytes = Vector<uint8_t>; |
| |
| enum class DecoderError { |
| CBORNoError = 0, |
| UnsupportedMajorType, |
| UnknownAdditionalInfo, |
| IncompleteCBORData, |
| IncorrectMapKeyType, |
| TooMuchNesting, |
| InvalidUTF8, |
| ExtraneousData, |
| DuplicateKey, |
| OutOfOrderKey, |
| NonMinimalCBOREncoding, |
| UnsupportedSimpleValue, |
| UnsupportedFloatingPointValue, |
| OutOfRangeIntegerValue, |
| }; |
| |
| // CBOR nested depth sufficient for most use cases. |
| static const int kCBORMaxDepth = 16; |
| |
| ~CBORReader(); |
| |
| // Reads and parses |input_data| into a CBORValue. If any one of the syntax |
| // formats is violated -including unknown additional info and incomplete |
| // CBOR data- then an empty optional is returned. Optional |errorCodeOut| |
| // can be provided by the caller to obtain additional information about |
| // decoding failures. |
| WEBCORE_EXPORT static Optional<CBORValue> read(const Bytes&, DecoderError* errorCodeOut = nullptr, int maxNestingLevel = kCBORMaxDepth); |
| |
| // Translates errors to human-readable error messages. |
| static const char* errorCodeToString(DecoderError errorCode); |
| |
| private: |
| CBORReader(Bytes::const_iterator, const Bytes::const_iterator); |
| Optional<CBORValue> decodeCBOR(int maxNestingLevel); |
| Optional<CBORValue> decodeValueToNegative(uint64_t value); |
| Optional<CBORValue> decodeValueToUnsigned(uint64_t value); |
| Optional<CBORValue> readSimpleValue(uint8_t additionalInfo, uint64_t value); |
| bool readVariadicLengthInteger(uint8_t additionalInfo, uint64_t* value); |
| Optional<CBORValue> readBytes(uint64_t numBytes); |
| Optional<CBORValue> readString(uint64_t numBytes); |
| Optional<CBORValue> readCBORArray(uint64_t length, int maxNestingLevel); |
| Optional<CBORValue> readCBORMap(uint64_t length, int maxNestingLevel); |
| bool canConsume(uint64_t bytes); |
| void checkExtraneousData(); |
| bool checkDuplicateKey(const CBORValue& newKey, const CBORValue::MapValue&); |
| bool hasValidUTF8Format(const String&); |
| bool checkOutOfOrderKey(const CBORValue& newKey, const CBORValue::MapValue&); |
| bool checkMinimalEncoding(uint8_t additionalBytes, uint64_t uintData); |
| |
| DecoderError getErrorCode(); |
| |
| Bytes::const_iterator m_it; |
| const Bytes::const_iterator m_end; |
| DecoderError m_errorCode; |
| }; |
| |
| } // namespace cbor |
| |
| #endif // ENABLE(WEB_AUTHN) |