// Copyright 2015 The Chromium 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 NET_DER_PARSE_VALUES_H_ #define NET_DER_PARSE_VALUES_H_ #include #include "net/base/net_export.h" #include "net/der/input.h" #include "third_party/abseil-cpp/absl/types/optional.h" namespace net::der { // Reads a DER-encoded ASN.1 BOOLEAN value from |in| and puts the resulting // value in |out|. Returns whether the encoded value could successfully be // read. [[nodiscard]] NET_EXPORT bool ParseBool(const Input& in, bool* out); // Like ParseBool, except it is more relaxed in what inputs it accepts: Any // value that is a valid BER encoding will be parsed successfully. [[nodiscard]] NET_EXPORT bool ParseBoolRelaxed(const Input& in, bool* out); // Checks the validity of a DER-encoded ASN.1 INTEGER value from |in|, and // determines the sign of the number. Returns true on success and // fills |negative|. Otherwise returns false and does not modify the out // parameter. // // in: The value portion of an INTEGER. // negative: Out parameter that is set to true if the number is negative // and false otherwise (zero is non-negative). [[nodiscard]] NET_EXPORT bool IsValidInteger(const Input& in, bool* negative); // Reads a DER-encoded ASN.1 INTEGER value from |in| and puts the resulting // value in |out|. ASN.1 INTEGERs are arbitrary precision; this function is // provided as a convenience when the caller knows that the value is unsigned // and is between 0 and 2^64-1. This function returns false if the value is too // big to fit in a uint64_t, is negative, or if there is an error reading the // integer. [[nodiscard]] NET_EXPORT bool ParseUint64(const Input& in, uint64_t* out); // Same as ParseUint64() but for a uint8_t. [[nodiscard]] NET_EXPORT bool ParseUint8(const Input& in, uint8_t* out); // The BitString class is a helper for representing a valid parsed BIT STRING. // // * The bits are ordered within each octet of bytes() from most to least // significant, as in the DER encoding. // // * There may be at most 7 unused bits. class NET_EXPORT BitString { public: BitString() = default; // |unused_bits| represents the number of bits in the last octet of |bytes|, // starting from the least significant bit, that are unused. It MUST be < 8. // And if bytes is empty, then it MUST be 0. BitString(const Input& bytes, uint8_t unused_bits); const Input& bytes() const { return bytes_; } uint8_t unused_bits() const { return unused_bits_; } // Returns true if the bit string contains 1 at the specified position. // Otherwise returns false. // // A return value of false can mean either: // * The bit value at |bit_index| is 0. // * There is no bit at |bit_index| (index is beyond the end). [[nodiscard]] bool AssertsBit(size_t bit_index) const; private: Input bytes_; uint8_t unused_bits_ = 0; // Default assignment and copy constructor are OK. }; // Reads a DER-encoded ASN.1 BIT STRING value from |in| and returns the // resulting octet string and number of unused bits. // // On failure, returns absl::nullopt. [[nodiscard]] NET_EXPORT absl::optional ParseBitString( const Input& in); struct NET_EXPORT GeneralizedTime { uint16_t year; uint8_t month; uint8_t day; uint8_t hours; uint8_t minutes; uint8_t seconds; // Returns true if the value is in UTCTime's range. bool InUTCTimeRange() const; }; NET_EXPORT_PRIVATE bool operator<(const GeneralizedTime& lhs, const GeneralizedTime& rhs); NET_EXPORT_PRIVATE bool operator<=(const GeneralizedTime& lhs, const GeneralizedTime& rhs); NET_EXPORT_PRIVATE bool operator>(const GeneralizedTime& lhs, const GeneralizedTime& rhs); NET_EXPORT_PRIVATE bool operator>=(const GeneralizedTime& lhs, const GeneralizedTime& rhs); // Reads a DER-encoded ASN.1 UTCTime value from |in| and puts the resulting // value in |out|, returning true if the UTCTime could be parsed successfully. [[nodiscard]] NET_EXPORT bool ParseUTCTime(const Input& in, GeneralizedTime* out); // Reads a DER-encoded ASN.1 GeneralizedTime value from |in| and puts the // resulting value in |out|, returning true if the GeneralizedTime could // be parsed successfully. This function is even more restrictive than the // DER rules - it follows the rules from RFC5280, which does not allow for // fractional seconds. [[nodiscard]] NET_EXPORT bool ParseGeneralizedTime(const Input& in, GeneralizedTime* out); // Reads a DER-encoded ASN.1 IA5String value from |in| and stores the result in // |out| as ASCII, returning true if successful. [[nodiscard]] NET_EXPORT bool ParseIA5String(Input in, std::string* out); // Reads a DER-encoded ASN.1 VisibleString value from |in| and stores the result // in |out| as ASCII, returning true if successful. [[nodiscard]] NET_EXPORT bool ParseVisibleString(Input in, std::string* out); // Reads a DER-encoded ASN.1 PrintableString value from |in| and stores the // result in |out| as ASCII, returning true if successful. [[nodiscard]] NET_EXPORT bool ParsePrintableString(Input in, std::string* out); // Reads a DER-encoded ASN.1 TeletexString value from |in|, treating it as // Latin-1, and stores the result in |out| as UTF-8, returning true if // successful. // // This is for compatibility with legacy implementations that would use Latin-1 // encoding but tag it as TeletexString. [[nodiscard]] NET_EXPORT bool ParseTeletexStringAsLatin1(Input in, std::string* out); // Reads a DER-encoded ASN.1 UniversalString value from |in| and stores the // result in |out| as UTF-8, returning true if successful. [[nodiscard]] NET_EXPORT bool ParseUniversalString(Input in, std::string* out); // Reads a DER-encoded ASN.1 BMPString value from |in| and stores the // result in |out| as UTF-8, returning true if successful. [[nodiscard]] NET_EXPORT bool ParseBmpString(Input in, std::string* out); } // namespace net::der #endif // NET_DER_PARSE_VALUES_H_