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// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BSSL_DER_PARSE_VALUES_H_
#define BSSL_DER_PARSE_VALUES_H_
#include "fillins/openssl_util.h"
#include <stdint.h>
#include "input.h"
#include <optional>
namespace bssl::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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_EXPORT bool ParseUint64(const Input& in, uint64_t* out);
// Same as ParseUint64() but for a uint8_t.
[[nodiscard]] OPENSSL_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 OPENSSL_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 std::nullopt.
[[nodiscard]] OPENSSL_EXPORT std::optional<BitString> ParseBitString(
const Input& in);
struct OPENSSL_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;
};
OPENSSL_EXPORT bool operator<(const GeneralizedTime& lhs,
const GeneralizedTime& rhs);
OPENSSL_EXPORT bool operator<=(const GeneralizedTime& lhs,
const GeneralizedTime& rhs);
OPENSSL_EXPORT bool operator>(const GeneralizedTime& lhs,
const GeneralizedTime& rhs);
OPENSSL_EXPORT 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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_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]] OPENSSL_EXPORT bool ParseBmpString(Input in, std::string* out);
} // namespace bssl::der
#endif // BSSL_DER_PARSE_VALUES_H_