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Diffstat (limited to 'CryptoPP/integer.h')
| -rw-r--r-- | CryptoPP/integer.h | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/CryptoPP/integer.h b/CryptoPP/integer.h new file mode 100644 index 000000000..6d844fa57 --- /dev/null +++ b/CryptoPP/integer.h @@ -0,0 +1,420 @@ +#ifndef CRYPTOPP_INTEGER_H +#define CRYPTOPP_INTEGER_H + +/** \file */ + +#include "cryptlib.h" +#include "secblock.h" + +#include <iosfwd> +#include <algorithm> + +NAMESPACE_BEGIN(CryptoPP) + +struct InitializeInteger // used to initialize static variables +{ + InitializeInteger(); +}; + +typedef SecBlock<word, AllocatorWithCleanup<word, CRYPTOPP_BOOL_X86> > IntegerSecBlock; + +//! multiple precision integer and basic arithmetics +/*! This class can represent positive and negative integers + with absolute value less than (256**sizeof(word)) ** (256**sizeof(int)). + \nosubgrouping +*/ +class CRYPTOPP_DLL Integer : private InitializeInteger, public ASN1Object +{ +public: + //! \name ENUMS, EXCEPTIONS, and TYPEDEFS + //@{ + //! division by zero exception + class DivideByZero : public Exception + { + public: + DivideByZero() : Exception(OTHER_ERROR, "Integer: division by zero") {} + }; + + //! + class RandomNumberNotFound : public Exception + { + public: + RandomNumberNotFound() : Exception(OTHER_ERROR, "Integer: no integer satisfies the given parameters") {} + }; + + //! + enum Sign {POSITIVE=0, NEGATIVE=1}; + + //! + enum Signedness { + //! + UNSIGNED, + //! + SIGNED}; + + //! + enum RandomNumberType { + //! + ANY, + //! + PRIME}; + //@} + + //! \name CREATORS + //@{ + //! creates the zero integer + Integer(); + + //! copy constructor + Integer(const Integer& t); + + //! convert from signed long + Integer(signed long value); + + //! convert from lword + Integer(Sign s, lword value); + + //! convert from two words + Integer(Sign s, word highWord, word lowWord); + + //! convert from string + /*! str can be in base 2, 8, 10, or 16. Base is determined by a + case insensitive suffix of 'h', 'o', or 'b'. No suffix means base 10. + */ + explicit Integer(const char *str); + explicit Integer(const wchar_t *str); + + //! convert from big-endian byte array + Integer(const byte *encodedInteger, size_t byteCount, Signedness s=UNSIGNED); + + //! convert from big-endian form stored in a BufferedTransformation + Integer(BufferedTransformation &bt, size_t byteCount, Signedness s=UNSIGNED); + + //! convert from BER encoded byte array stored in a BufferedTransformation object + explicit Integer(BufferedTransformation &bt); + + //! create a random integer + /*! The random integer created is uniformly distributed over [0, 2**bitcount). */ + Integer(RandomNumberGenerator &rng, size_t bitcount); + + //! avoid calling constructors for these frequently used integers + static const Integer & CRYPTOPP_API Zero(); + //! avoid calling constructors for these frequently used integers + static const Integer & CRYPTOPP_API One(); + //! avoid calling constructors for these frequently used integers + static const Integer & CRYPTOPP_API Two(); + + //! create a random integer of special type + /*! Ideally, the random integer created should be uniformly distributed + over {x | min <= x <= max and x is of rnType and x % mod == equiv}. + However the actual distribution may not be uniform because sequential + search is used to find an appropriate number from a random starting + point. + May return (with very small probability) a pseudoprime when a prime + is requested and max > lastSmallPrime*lastSmallPrime (lastSmallPrime + is declared in nbtheory.h). + \throw RandomNumberNotFound if the set is empty. + */ + Integer(RandomNumberGenerator &rng, const Integer &min, const Integer &max, RandomNumberType rnType=ANY, const Integer &equiv=Zero(), const Integer &mod=One()); + + //! return the integer 2**e + static Integer CRYPTOPP_API Power2(size_t e); + //@} + + //! \name ENCODE/DECODE + //@{ + //! minimum number of bytes to encode this integer + /*! MinEncodedSize of 0 is 1 */ + size_t MinEncodedSize(Signedness=UNSIGNED) const; + //! encode in big-endian format + /*! unsigned means encode absolute value, signed means encode two's complement if negative. + if outputLen < MinEncodedSize, the most significant bytes will be dropped + if outputLen > MinEncodedSize, the most significant bytes will be padded + */ + void Encode(byte *output, size_t outputLen, Signedness=UNSIGNED) const; + //! + void Encode(BufferedTransformation &bt, size_t outputLen, Signedness=UNSIGNED) const; + + //! encode using Distinguished Encoding Rules, put result into a BufferedTransformation object + void DEREncode(BufferedTransformation &bt) const; + + //! encode absolute value as big-endian octet string + void DEREncodeAsOctetString(BufferedTransformation &bt, size_t length) const; + + //! encode absolute value in OpenPGP format, return length of output + size_t OpenPGPEncode(byte *output, size_t bufferSize) const; + //! encode absolute value in OpenPGP format, put result into a BufferedTransformation object + size_t OpenPGPEncode(BufferedTransformation &bt) const; + + //! + void Decode(const byte *input, size_t inputLen, Signedness=UNSIGNED); + //! + //* Precondition: bt.MaxRetrievable() >= inputLen + void Decode(BufferedTransformation &bt, size_t inputLen, Signedness=UNSIGNED); + + //! + void BERDecode(const byte *input, size_t inputLen); + //! + void BERDecode(BufferedTransformation &bt); + + //! decode nonnegative value as big-endian octet string + void BERDecodeAsOctetString(BufferedTransformation &bt, size_t length); + + class OpenPGPDecodeErr : public Exception + { + public: + OpenPGPDecodeErr() : Exception(INVALID_DATA_FORMAT, "OpenPGP decode error") {} + }; + + //! + void OpenPGPDecode(const byte *input, size_t inputLen); + //! + void OpenPGPDecode(BufferedTransformation &bt); + //@} + + //! \name ACCESSORS + //@{ + //! return true if *this can be represented as a signed long + bool IsConvertableToLong() const; + //! return equivalent signed long if possible, otherwise undefined + signed long ConvertToLong() const; + + //! number of significant bits = floor(log2(abs(*this))) + 1 + unsigned int BitCount() const; + //! number of significant bytes = ceiling(BitCount()/8) + unsigned int ByteCount() const; + //! number of significant words = ceiling(ByteCount()/sizeof(word)) + unsigned int WordCount() const; + + //! return the i-th bit, i=0 being the least significant bit + bool GetBit(size_t i) const; + //! return the i-th byte + byte GetByte(size_t i) const; + //! return n lowest bits of *this >> i + lword GetBits(size_t i, size_t n) const; + + //! + bool IsZero() const {return !*this;} + //! + bool NotZero() const {return !IsZero();} + //! + bool IsNegative() const {return sign == NEGATIVE;} + //! + bool NotNegative() const {return !IsNegative();} + //! + bool IsPositive() const {return NotNegative() && NotZero();} + //! + bool NotPositive() const {return !IsPositive();} + //! + bool IsEven() const {return GetBit(0) == 0;} + //! + bool IsOdd() const {return GetBit(0) == 1;} + //@} + + //! \name MANIPULATORS + //@{ + //! + Integer& operator=(const Integer& t); + + //! + Integer& operator+=(const Integer& t); + //! + Integer& operator-=(const Integer& t); + //! + Integer& operator*=(const Integer& t) {return *this = Times(t);} + //! + Integer& operator/=(const Integer& t) {return *this = DividedBy(t);} + //! + Integer& operator%=(const Integer& t) {return *this = Modulo(t);} + //! + Integer& operator/=(word t) {return *this = DividedBy(t);} + //! + Integer& operator%=(word t) {return *this = Integer(POSITIVE, 0, Modulo(t));} + + //! + Integer& operator<<=(size_t); + //! + Integer& operator>>=(size_t); + + //! + void Randomize(RandomNumberGenerator &rng, size_t bitcount); + //! + void Randomize(RandomNumberGenerator &rng, const Integer &min, const Integer &max); + //! set this Integer to a random element of {x | min <= x <= max and x is of rnType and x % mod == equiv} + /*! returns false if the set is empty */ + bool Randomize(RandomNumberGenerator &rng, const Integer &min, const Integer &max, RandomNumberType rnType, const Integer &equiv=Zero(), const Integer &mod=One()); + + bool GenerateRandomNoThrow(RandomNumberGenerator &rng, const NameValuePairs ¶ms = g_nullNameValuePairs); + void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs ¶ms = g_nullNameValuePairs) + { + if (!GenerateRandomNoThrow(rng, params)) + throw RandomNumberNotFound(); + } + + //! set the n-th bit to value + void SetBit(size_t n, bool value=1); + //! set the n-th byte to value + void SetByte(size_t n, byte value); + + //! + void Negate(); + //! + void SetPositive() {sign = POSITIVE;} + //! + void SetNegative() {if (!!(*this)) sign = NEGATIVE;} + + //! + void swap(Integer &a); + //@} + + //! \name UNARY OPERATORS + //@{ + //! + bool operator!() const; + //! + Integer operator+() const {return *this;} + //! + Integer operator-() const; + //! + Integer& operator++(); + //! + Integer& operator--(); + //! + Integer operator++(int) {Integer temp = *this; ++*this; return temp;} + //! + Integer operator--(int) {Integer temp = *this; --*this; return temp;} + //@} + + //! \name BINARY OPERATORS + //@{ + //! signed comparison + /*! \retval -1 if *this < a + \retval 0 if *this = a + \retval 1 if *this > a + */ + int Compare(const Integer& a) const; + + //! + Integer Plus(const Integer &b) const; + //! + Integer Minus(const Integer &b) const; + //! + Integer Times(const Integer &b) const; + //! + Integer DividedBy(const Integer &b) const; + //! + Integer Modulo(const Integer &b) const; + //! + Integer DividedBy(word b) const; + //! + word Modulo(word b) const; + + //! + Integer operator>>(size_t n) const {return Integer(*this)>>=n;} + //! + Integer operator<<(size_t n) const {return Integer(*this)<<=n;} + //@} + + //! \name OTHER ARITHMETIC FUNCTIONS + //@{ + //! + Integer AbsoluteValue() const; + //! + Integer Doubled() const {return Plus(*this);} + //! + Integer Squared() const {return Times(*this);} + //! extract square root, if negative return 0, else return floor of square root + Integer SquareRoot() const; + //! return whether this integer is a perfect square + bool IsSquare() const; + + //! is 1 or -1 + bool IsUnit() const; + //! return inverse if 1 or -1, otherwise return 0 + Integer MultiplicativeInverse() const; + + //! modular multiplication + CRYPTOPP_DLL friend Integer CRYPTOPP_API a_times_b_mod_c(const Integer &x, const Integer& y, const Integer& m); + //! modular exponentiation + CRYPTOPP_DLL friend Integer CRYPTOPP_API a_exp_b_mod_c(const Integer &x, const Integer& e, const Integer& m); + + //! calculate r and q such that (a == d*q + r) && (0 <= r < abs(d)) + static void CRYPTOPP_API Divide(Integer &r, Integer &q, const Integer &a, const Integer &d); + //! use a faster division algorithm when divisor is short + static void CRYPTOPP_API Divide(word &r, Integer &q, const Integer &a, word d); + + //! returns same result as Divide(r, q, a, Power2(n)), but faster + static void CRYPTOPP_API DivideByPowerOf2(Integer &r, Integer &q, const Integer &a, unsigned int n); + + //! greatest common divisor + static Integer CRYPTOPP_API Gcd(const Integer &a, const Integer &n); + //! calculate multiplicative inverse of *this mod n + Integer InverseMod(const Integer &n) const; + //! + word InverseMod(word n) const; + //@} + + //! \name INPUT/OUTPUT + //@{ + //! + friend CRYPTOPP_DLL std::istream& CRYPTOPP_API operator>>(std::istream& in, Integer &a); + //! + friend CRYPTOPP_DLL std::ostream& CRYPTOPP_API operator<<(std::ostream& out, const Integer &a); + //@} + +private: + friend class ModularArithmetic; + friend class MontgomeryRepresentation; + friend class HalfMontgomeryRepresentation; + + Integer(word value, size_t length); + + int PositiveCompare(const Integer &t) const; + friend void PositiveAdd(Integer &sum, const Integer &a, const Integer &b); + friend void PositiveSubtract(Integer &diff, const Integer &a, const Integer &b); + friend void PositiveMultiply(Integer &product, const Integer &a, const Integer &b); + friend void PositiveDivide(Integer &remainder, Integer "ient, const Integer ÷nd, const Integer &divisor); + + IntegerSecBlock reg; + Sign sign; +}; + +//! +inline bool operator==(const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)==0;} +//! +inline bool operator!=(const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)!=0;} +//! +inline bool operator> (const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)> 0;} +//! +inline bool operator>=(const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)>=0;} +//! +inline bool operator< (const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)< 0;} +//! +inline bool operator<=(const CryptoPP::Integer& a, const CryptoPP::Integer& b) {return a.Compare(b)<=0;} +//! +inline CryptoPP::Integer operator+(const CryptoPP::Integer &a, const CryptoPP::Integer &b) {return a.Plus(b);} +//! +inline CryptoPP::Integer operator-(const CryptoPP::Integer &a, const CryptoPP::Integer &b) {return a.Minus(b);} +//! +inline CryptoPP::Integer operator*(const CryptoPP::Integer &a, const CryptoPP::Integer &b) {return a.Times(b);} +//! +inline CryptoPP::Integer operator/(const CryptoPP::Integer &a, const CryptoPP::Integer &b) {return a.DividedBy(b);} +//! +inline CryptoPP::Integer operator%(const CryptoPP::Integer &a, const CryptoPP::Integer &b) {return a.Modulo(b);} +//! +inline CryptoPP::Integer operator/(const CryptoPP::Integer &a, CryptoPP::word b) {return a.DividedBy(b);} +//! +inline CryptoPP::word operator%(const CryptoPP::Integer &a, CryptoPP::word b) {return a.Modulo(b);} + +NAMESPACE_END + +#ifndef __BORLANDC__ +NAMESPACE_BEGIN(std) +inline void swap(CryptoPP::Integer &a, CryptoPP::Integer &b) +{ + a.swap(b); +} +NAMESPACE_END +#endif + +#endif |