From 3438e5d3ddf8444f0e31009ffbe8237ef3752c22 Mon Sep 17 00:00:00 2001 From: Alexander Harkness Date: Sun, 24 Nov 2013 14:21:13 +0000 Subject: move cryptopp into lib --- lib/cryptopp/integer.cpp | 4235 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 4235 insertions(+) create mode 100644 lib/cryptopp/integer.cpp (limited to 'lib/cryptopp/integer.cpp') diff --git a/lib/cryptopp/integer.cpp b/lib/cryptopp/integer.cpp new file mode 100644 index 000000000..f07cce873 --- /dev/null +++ b/lib/cryptopp/integer.cpp @@ -0,0 +1,4235 @@ +// integer.cpp - written and placed in the public domain by Wei Dai +// contains public domain code contributed by Alister Lee and Leonard Janke + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "integer.h" +#include "modarith.h" +#include "nbtheory.h" +#include "asn.h" +#include "oids.h" +#include "words.h" +#include "algparam.h" +#include "pubkey.h" // for P1363_KDF2 +#include "sha.h" +#include "cpu.h" + +#include + +#if _MSC_VER >= 1400 + #include +#endif + +#ifdef __DECCXX + #include +#endif + +#ifdef CRYPTOPP_MSVC6_NO_PP + #pragma message("You do not seem to have the Visual C++ Processor Pack installed, so use of SSE2 instructions will be disabled.") +#endif + +#define CRYPTOPP_INTEGER_SSE2 (CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE && CRYPTOPP_BOOL_X86) + +NAMESPACE_BEGIN(CryptoPP) + +bool AssignIntToInteger(const std::type_info &valueType, void *pInteger, const void *pInt) +{ + if (valueType != typeid(Integer)) + return false; + *reinterpret_cast(pInteger) = *reinterpret_cast(pInt); + return true; +} + +inline static int Compare(const word *A, const word *B, size_t N) +{ + while (N--) + if (A[N] > B[N]) + return 1; + else if (A[N] < B[N]) + return -1; + + return 0; +} + +inline static int Increment(word *A, size_t N, word B=1) +{ + assert(N); + word t = A[0]; + A[0] = t+B; + if (A[0] >= t) + return 0; + for (unsigned i=1; i>(WORD_BITS-1)); d##0 = 2*d##0 + (c>>(WORD_BITS-1)); c *= 2; + #endif + #ifndef Acc2WordsBy2 + #define Acc2WordsBy2(a, b) a##0 += b##0; a##1 += a##0 < b##0; a##1 += b##1; + #endif + #define AddWithCarry(u, a, b) {word t = a+b; u##0 = t + u##1; u##1 = (ta) + (u##0>t);} + #define GetCarry(u) u##1 + #define GetBorrow(u) u##1 +#else + #define Declare2Words(x) dword x; + #if _MSC_VER >= 1400 && !defined(__INTEL_COMPILER) + #define MultiplyWords(p, a, b) p = __emulu(a, b); + #else + #define MultiplyWords(p, a, b) p = (dword)a*b; + #endif + #define AssignWord(a, b) a = b; + #define Add2WordsBy1(a, b, c) a = b + c; + #define Acc2WordsBy2(a, b) a += b; + #define LowWord(a) word(a) + #define HighWord(a) word(a>>WORD_BITS) + #define Double3Words(c, d) d = 2*d + (c>>(WORD_BITS-1)); c *= 2; + #define AddWithCarry(u, a, b) u = dword(a) + b + GetCarry(u); + #define SubtractWithBorrow(u, a, b) u = dword(a) - b - GetBorrow(u); + #define GetCarry(u) HighWord(u) + #define GetBorrow(u) word(u>>(WORD_BITS*2-1)) +#endif +#ifndef MulAcc + #define MulAcc(c, d, a, b) MultiplyWords(p, a, b); Acc2WordsBy1(p, c); c = LowWord(p); Acc2WordsBy1(d, HighWord(p)); +#endif +#ifndef Acc2WordsBy1 + #define Acc2WordsBy1(a, b) Add2WordsBy1(a, a, b) +#endif +#ifndef Acc3WordsBy2 + #define Acc3WordsBy2(c, d, e) Acc2WordsBy1(e, c); c = LowWord(e); Add2WordsBy1(e, d, HighWord(e)); +#endif + +class DWord +{ +public: + DWord() {} + +#ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + explicit DWord(word low) + { + m_whole = low; + } +#else + explicit DWord(word low) + { + m_halfs.low = low; + m_halfs.high = 0; + } +#endif + + DWord(word low, word high) + { + m_halfs.low = low; + m_halfs.high = high; + } + + static DWord Multiply(word a, word b) + { + DWord r; + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + r.m_whole = (dword)a * b; + #elif defined(MultiplyWordsLoHi) + MultiplyWordsLoHi(r.m_halfs.low, r.m_halfs.high, a, b); + #endif + return r; + } + + static DWord MultiplyAndAdd(word a, word b, word c) + { + DWord r = Multiply(a, b); + return r += c; + } + + DWord & operator+=(word a) + { + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + m_whole = m_whole + a; + #else + m_halfs.low += a; + m_halfs.high += (m_halfs.low < a); + #endif + return *this; + } + + DWord operator+(word a) + { + DWord r; + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + r.m_whole = m_whole + a; + #else + r.m_halfs.low = m_halfs.low + a; + r.m_halfs.high = m_halfs.high + (r.m_halfs.low < a); + #endif + return r; + } + + DWord operator-(DWord a) + { + DWord r; + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + r.m_whole = m_whole - a.m_whole; + #else + r.m_halfs.low = m_halfs.low - a.m_halfs.low; + r.m_halfs.high = m_halfs.high - a.m_halfs.high - (r.m_halfs.low > m_halfs.low); + #endif + return r; + } + + DWord operator-(word a) + { + DWord r; + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + r.m_whole = m_whole - a; + #else + r.m_halfs.low = m_halfs.low - a; + r.m_halfs.high = m_halfs.high - (r.m_halfs.low > m_halfs.low); + #endif + return r; + } + + // returns quotient, which must fit in a word + word operator/(word divisor); + + word operator%(word a); + + bool operator!() const + { + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + return !m_whole; + #else + return !m_halfs.high && !m_halfs.low; + #endif + } + + word GetLowHalf() const {return m_halfs.low;} + word GetHighHalf() const {return m_halfs.high;} + word GetHighHalfAsBorrow() const {return 0-m_halfs.high;} + +private: + union + { + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + dword m_whole; + #endif + struct + { + #ifdef IS_LITTLE_ENDIAN + word low; + word high; + #else + word high; + word low; + #endif + } m_halfs; + }; +}; + +class Word +{ +public: + Word() {} + + Word(word value) + { + m_whole = value; + } + + Word(hword low, hword high) + { + m_whole = low | (word(high) << (WORD_BITS/2)); + } + + static Word Multiply(hword a, hword b) + { + Word r; + r.m_whole = (word)a * b; + return r; + } + + Word operator-(Word a) + { + Word r; + r.m_whole = m_whole - a.m_whole; + return r; + } + + Word operator-(hword a) + { + Word r; + r.m_whole = m_whole - a; + return r; + } + + // returns quotient, which must fit in a word + hword operator/(hword divisor) + { + return hword(m_whole / divisor); + } + + bool operator!() const + { + return !m_whole; + } + + word GetWhole() const {return m_whole;} + hword GetLowHalf() const {return hword(m_whole);} + hword GetHighHalf() const {return hword(m_whole>>(WORD_BITS/2));} + hword GetHighHalfAsBorrow() const {return 0-hword(m_whole>>(WORD_BITS/2));} + +private: + word m_whole; +}; + +// do a 3 word by 2 word divide, returns quotient and leaves remainder in A +template +S DivideThreeWordsByTwo(S *A, S B0, S B1, D *dummy=NULL) +{ + // assert {A[2],A[1]} < {B1,B0}, so quotient can fit in a S + assert(A[2] < B1 || (A[2]==B1 && A[1] < B0)); + + // estimate the quotient: do a 2 S by 1 S divide + S Q; + if (S(B1+1) == 0) + Q = A[2]; + else if (B1 > 0) + Q = D(A[1], A[2]) / S(B1+1); + else + Q = D(A[0], A[1]) / B0; + + // now subtract Q*B from A + D p = D::Multiply(B0, Q); + D u = (D) A[0] - p.GetLowHalf(); + A[0] = u.GetLowHalf(); + u = (D) A[1] - p.GetHighHalf() - u.GetHighHalfAsBorrow() - D::Multiply(B1, Q); + A[1] = u.GetLowHalf(); + A[2] += u.GetHighHalf(); + + // Q <= actual quotient, so fix it + while (A[2] || A[1] > B1 || (A[1]==B1 && A[0]>=B0)) + { + u = (D) A[0] - B0; + A[0] = u.GetLowHalf(); + u = (D) A[1] - B1 - u.GetHighHalfAsBorrow(); + A[1] = u.GetLowHalf(); + A[2] += u.GetHighHalf(); + Q++; + assert(Q); // shouldn't overflow + } + + return Q; +} + +// do a 4 word by 2 word divide, returns 2 word quotient in Q0 and Q1 +template +inline D DivideFourWordsByTwo(S *T, const D &Al, const D &Ah, const D &B) +{ + if (!B) // if divisor is 0, we assume divisor==2**(2*WORD_BITS) + return D(Ah.GetLowHalf(), Ah.GetHighHalf()); + else + { + S Q[2]; + T[0] = Al.GetLowHalf(); + T[1] = Al.GetHighHalf(); + T[2] = Ah.GetLowHalf(); + T[3] = Ah.GetHighHalf(); + Q[1] = DivideThreeWordsByTwo(T+1, B.GetLowHalf(), B.GetHighHalf()); + Q[0] = DivideThreeWordsByTwo(T, B.GetLowHalf(), B.GetHighHalf()); + return D(Q[0], Q[1]); + } +} + +// returns quotient, which must fit in a word +inline word DWord::operator/(word a) +{ + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + return word(m_whole / a); + #else + hword r[4]; + return DivideFourWordsByTwo(r, m_halfs.low, m_halfs.high, a).GetWhole(); + #endif +} + +inline word DWord::operator%(word a) +{ + #ifdef CRYPTOPP_NATIVE_DWORD_AVAILABLE + return word(m_whole % a); + #else + if (a < (word(1) << (WORD_BITS/2))) + { + hword h = hword(a); + word r = m_halfs.high % h; + r = ((m_halfs.low >> (WORD_BITS/2)) + (r << (WORD_BITS/2))) % h; + return hword((hword(m_halfs.low) + (r << (WORD_BITS/2))) % h); + } + else + { + hword r[4]; + DivideFourWordsByTwo(r, m_halfs.low, m_halfs.high, a); + return Word(r[0], r[1]).GetWhole(); + } + #endif +} + +// ******************************************************** + +// use some tricks to share assembly code between MSVC and GCC +#if defined(__GNUC__) + #define AddPrologue \ + int result; \ + __asm__ __volatile__ \ + ( \ + ".intel_syntax noprefix;" + #define AddEpilogue \ + ".att_syntax prefix;" \ + : "=a" (result)\ + : "d" (C), "a" (A), "D" (B), "c" (N) \ + : "%esi", "memory", "cc" \ + );\ + return result; + #define MulPrologue \ + __asm__ __volatile__ \ + ( \ + ".intel_syntax noprefix;" \ + AS1( push ebx) \ + AS2( mov ebx, edx) + #define MulEpilogue \ + AS1( pop ebx) \ + ".att_syntax prefix;" \ + : \ + : "d" (s_maskLow16), "c" (C), "a" (A), "D" (B) \ + : "%esi", "memory", "cc" \ + ); + #define SquPrologue MulPrologue + #define SquEpilogue \ + AS1( pop ebx) \ + ".att_syntax prefix;" \ + : \ + : "d" (s_maskLow16), "c" (C), "a" (A) \ + : "%esi", "%edi", "memory", "cc" \ + ); + #define TopPrologue MulPrologue + #define TopEpilogue \ + AS1( pop ebx) \ + ".att_syntax prefix;" \ + : \ + : "d" (s_maskLow16), "c" (C), "a" (A), "D" (B), "S" (L) \ + : "memory", "cc" \ + ); +#else + #define AddPrologue \ + __asm push edi \ + __asm push esi \ + __asm mov eax, [esp+12] \ + __asm mov edi, [esp+16] + #define AddEpilogue \ + __asm pop esi \ + __asm pop edi \ + __asm ret 8 +#if _MSC_VER < 1300 + #define SaveEBX __asm push ebx + #define RestoreEBX __asm pop ebx +#else + #define SaveEBX + #define RestoreEBX +#endif + #define SquPrologue \ + AS2( mov eax, A) \ + AS2( mov ecx, C) \ + SaveEBX \ + AS2( lea ebx, s_maskLow16) + #define MulPrologue \ + AS2( mov eax, A) \ + AS2( mov edi, B) \ + AS2( mov ecx, C) \ + SaveEBX \ + AS2( lea ebx, s_maskLow16) + #define TopPrologue \ + AS2( mov eax, A) \ + AS2( mov edi, B) \ + AS2( mov ecx, C) \ + AS2( mov esi, L) \ + SaveEBX \ + AS2( lea ebx, s_maskLow16) + #define SquEpilogue RestoreEBX + #define MulEpilogue RestoreEBX + #define TopEpilogue RestoreEBX +#endif + +#ifdef CRYPTOPP_X64_MASM_AVAILABLE +extern "C" { +int Baseline_Add(size_t N, word *C, const word *A, const word *B); +int Baseline_Sub(size_t N, word *C, const word *A, const word *B); +} +#elif defined(CRYPTOPP_X64_ASM_AVAILABLE) && defined(__GNUC__) && defined(CRYPTOPP_WORD128_AVAILABLE) +int Baseline_Add(size_t N, word *C, const word *A, const word *B) +{ + word result; + __asm__ __volatile__ + ( + ".intel_syntax;" + AS1( neg %1) + ASJ( jz, 1, f) + AS2( mov %0,[%3+8*%1]) + AS2( add %0,[%4+8*%1]) + AS2( mov [%2+8*%1],%0) + ASL(0) + AS2( mov %0,[%3+8*%1+8]) + AS2( adc %0,[%4+8*%1+8]) + AS2( mov [%2+8*%1+8],%0) + AS2( lea %1,[%1+2]) + ASJ( jrcxz, 1, f) + AS2( mov %0,[%3+8*%1]) + AS2( adc %0,[%4+8*%1]) + AS2( mov [%2+8*%1],%0) + ASJ( jmp, 0, b) + ASL(1) + AS2( mov %0, 0) + AS2( adc %0, %0) + ".att_syntax;" + : "=&r" (result), "+c" (N) + : "r" (C+N), "r" (A+N), "r" (B+N) + : "memory", "cc" + ); + return (int)result; +} + +int Baseline_Sub(size_t N, word *C, const word *A, const word *B) +{ + word result; + __asm__ __volatile__ + ( + ".intel_syntax;" + AS1( neg %1) + ASJ( jz, 1, f) + AS2( mov %0,[%3+8*%1]) + AS2( sub %0,[%4+8*%1]) + AS2( mov [%2+8*%1],%0) + ASL(0) + AS2( mov %0,[%3+8*%1+8]) + AS2( sbb %0,[%4+8*%1+8]) + AS2( mov [%2+8*%1+8],%0) + AS2( lea %1,[%1+2]) + ASJ( jrcxz, 1, f) + AS2( mov %0,[%3+8*%1]) + AS2( sbb %0,[%4+8*%1]) + AS2( mov [%2+8*%1],%0) + ASJ( jmp, 0, b) + ASL(1) + AS2( mov %0, 0) + AS2( adc %0, %0) + ".att_syntax;" + : "=&r" (result), "+c" (N) + : "r" (C+N), "r" (A+N), "r" (B+N) + : "memory", "cc" + ); + return (int)result; +} +#elif defined(CRYPTOPP_X86_ASM_AVAILABLE) && CRYPTOPP_BOOL_X86 +CRYPTOPP_NAKED int CRYPTOPP_FASTCALL Baseline_Add(size_t N, word *C, const word *A, const word *B) +{ + AddPrologue + + // now: eax = A, edi = B, edx = C, ecx = N + AS2( lea eax, [eax+4*ecx]) + AS2( lea edi, [edi+4*ecx]) + AS2( lea edx, [edx+4*ecx]) + + AS1( neg ecx) // ecx is negative index + AS2( test ecx, 2) // this clears carry flag + ASJ( jz, 0, f) + AS2( sub ecx, 2) + ASJ( jmp, 1, f) + + ASL(0) + ASJ( jecxz, 2, f) // loop until ecx overflows and becomes zero + AS2( mov esi,[eax+4*ecx]) + AS2( adc esi,[edi+4*ecx]) + AS2( mov [edx+4*ecx],esi) + AS2( mov esi,[eax+4*ecx+4]) + AS2( adc esi,[edi+4*ecx+4]) + AS2( mov [edx+4*ecx+4],esi) + ASL(1) + AS2( mov esi,[eax+4*ecx+8]) + AS2( adc esi,[edi+4*ecx+8]) + AS2( mov [edx+4*ecx+8],esi) + AS2( mov esi,[eax+4*ecx+12]) + AS2( adc esi,[edi+4*ecx+12]) + AS2( mov [edx+4*ecx+12],esi) + + AS2( lea ecx,[ecx+4]) // advance index, avoid inc which causes slowdown on Intel Core 2 + ASJ( jmp, 0, b) + + ASL(2) + AS2( mov eax, 0) + AS1( setc al) // store carry into eax (return result register) + + AddEpilogue +} + +CRYPTOPP_NAKED int CRYPTOPP_FASTCALL Baseline_Sub(size_t N, word *C, const word *A, const word *B) +{ + AddPrologue + + // now: eax = A, edi = B, edx = C, ecx = N + AS2( lea eax, [eax+4*ecx]) + AS2( lea edi, [edi+4*ecx]) + AS2( lea edx, [edx+4*ecx]) + + AS1( neg ecx) // ecx is negative index + AS2( test ecx, 2) // this clears carry flag + ASJ( jz, 0, f) + AS2( sub ecx, 2) + ASJ( jmp, 1, f) + + ASL(0) + ASJ( jecxz, 2, f) // loop until ecx overflows and becomes zero + AS2( mov esi,[eax+4*ecx]) + AS2( sbb esi,[edi+4*ecx]) + AS2( mov [edx+4*ecx],esi) + AS2( mov esi,[eax+4*ecx+4]) + AS2( sbb esi,[edi+4*ecx+4]) + AS2( mov [edx+4*ecx+4],esi) + ASL(1) + AS2( mov esi,[eax+4*ecx+8]) + AS2( sbb esi,[edi+4*ecx+8]) + AS2( mov [edx+4*ecx+8],esi) + AS2( mov esi,[eax+4*ecx+12]) + AS2( sbb esi,[edi+4*ecx+12]) + AS2( mov [edx+4*ecx+12],esi) + + AS2( lea ecx,[ecx+4]) // advance index, avoid inc which causes slowdown on Intel Core 2 + ASJ( jmp, 0, b) + + ASL(2) + AS2( mov eax, 0) + AS1( setc al) // store carry into eax (return result register) + + AddEpilogue +} + +#if CRYPTOPP_INTEGER_SSE2 +CRYPTOPP_NAKED int CRYPTOPP_FASTCALL SSE2_Add(size_t N, word *C, const word *A, const word *B) +{ + AddPrologue + + // now: eax = A, edi = B, edx = C, ecx = N + AS2( lea eax, [eax+4*ecx]) + AS2( lea edi, [edi+4*ecx]) + AS2( lea edx, [edx+4*ecx]) + + AS1( neg ecx) // ecx is negative index + AS2( pxor mm2, mm2) + ASJ( jz, 2, f) + AS2( test ecx, 2) // this clears carry flag + ASJ( jz, 0, f) + AS2( sub ecx, 2) + ASJ( jmp, 1, f) + + ASL(0) + AS2( movd mm0, DWORD PTR [eax+4*ecx]) + AS2( movd mm1, DWORD PTR [edi+4*ecx]) + AS2( paddq mm0, mm1) + AS2( paddq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx], mm2) + AS2( psrlq mm2, 32) + + AS2( movd mm0, DWORD PTR [eax+4*ecx+4]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+4]) + AS2( paddq mm0, mm1) + AS2( paddq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx+4], mm2) + AS2( psrlq mm2, 32) + + ASL(1) + AS2( movd mm0, DWORD PTR [eax+4*ecx+8]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+8]) + AS2( paddq mm0, mm1) + AS2( paddq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx+8], mm2) + AS2( psrlq mm2, 32) + + AS2( movd mm0, DWORD PTR [eax+4*ecx+12]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+12]) + AS2( paddq mm0, mm1) + AS2( paddq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx+12], mm2) + AS2( psrlq mm2, 32) + + AS2( add ecx, 4) + ASJ( jnz, 0, b) + + ASL(2) + AS2( movd eax, mm2) + AS1( emms) + + AddEpilogue +} +CRYPTOPP_NAKED int CRYPTOPP_FASTCALL SSE2_Sub(size_t N, word *C, const word *A, const word *B) +{ + AddPrologue + + // now: eax = A, edi = B, edx = C, ecx = N + AS2( lea eax, [eax+4*ecx]) + AS2( lea edi, [edi+4*ecx]) + AS2( lea edx, [edx+4*ecx]) + + AS1( neg ecx) // ecx is negative index + AS2( pxor mm2, mm2) + ASJ( jz, 2, f) + AS2( test ecx, 2) // this clears carry flag + ASJ( jz, 0, f) + AS2( sub ecx, 2) + ASJ( jmp, 1, f) + + ASL(0) + AS2( movd mm0, DWORD PTR [eax+4*ecx]) + AS2( movd mm1, DWORD PTR [edi+4*ecx]) + AS2( psubq mm0, mm1) + AS2( psubq mm0, mm2) + AS2( movd DWORD PTR [edx+4*ecx], mm0) + AS2( psrlq mm0, 63) + + AS2( movd mm2, DWORD PTR [eax+4*ecx+4]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+4]) + AS2( psubq mm2, mm1) + AS2( psubq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx+4], mm2) + AS2( psrlq mm2, 63) + + ASL(1) + AS2( movd mm0, DWORD PTR [eax+4*ecx+8]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+8]) + AS2( psubq mm0, mm1) + AS2( psubq mm0, mm2) + AS2( movd DWORD PTR [edx+4*ecx+8], mm0) + AS2( psrlq mm0, 63) + + AS2( movd mm2, DWORD PTR [eax+4*ecx+12]) + AS2( movd mm1, DWORD PTR [edi+4*ecx+12]) + AS2( psubq mm2, mm1) + AS2( psubq mm2, mm0) + AS2( movd DWORD PTR [edx+4*ecx+12], mm2) + AS2( psrlq mm2, 63) + + AS2( add ecx, 4) + ASJ( jnz, 0, b) + + ASL(2) + AS2( movd eax, mm2) + AS1( emms) + + AddEpilogue +} +#endif // #if CRYPTOPP_BOOL_SSE2_ASM_AVAILABLE +#else +int CRYPTOPP_FASTCALL Baseline_Add(size_t N, word *C, const word *A, const word *B) +{ + assert (N%2 == 0); + + Declare2Words(u); + AssignWord(u, 0); + for (size_t i=0; i=2 && N%2==0); + + if (N <= s_recursionLimit) + s_pMul[N/4](R, A, B); + else + { + const size_t N2 = N/2; + + size_t AN2 = Compare(A0, A1, N2) > 0 ? 0 : N2; + Subtract(R0, A + AN2, A + (N2 ^ AN2), N2); + + size_t BN2 = Compare(B0, B1, N2) > 0 ? 0 : N2; + Subtract(R1, B + BN2, B + (N2 ^ BN2), N2); + + RecursiveMultiply(R2, T2, A1, B1, N2); + RecursiveMultiply(T0, T2, R0, R1, N2); + RecursiveMultiply(R0, T2, A0, B0, N2); + + // now T[01] holds (A1-A0)*(B0-B1), R[01] holds A0*B0, R[23] holds A1*B1 + + int c2 = Add(R2, R2, R1, N2); + int c3 = c2; + c2 += Add(R1, R2, R0, N2); + c3 += Add(R2, R2, R3, N2); + + if (AN2 == BN2) + c3 -= Subtract(R1, R1, T0, N); + else + c3 += Add(R1, R1, T0, N); + + c3 += Increment(R2, N2, c2); + assert (c3 >= 0 && c3 <= 2); + Increment(R3, N2, c3); + } +} + +// R[2*N] - result = A*A +// T[2*N] - temporary work space +// A[N] --- number to be squared + +void RecursiveSquare(word *R, word *T, const word *A, size_t N) +{ + assert(N && N%2==0); + + if (N <= s_recursionLimit) + s_pSqu[N/4](R, A); + else + { + const size_t N2 = N/2; + + RecursiveSquare(R0, T2, A0, N2); + RecursiveSquare(R2, T2, A1, N2); + RecursiveMultiply(T0, T2, A0, A1, N2); + + int carry = Add(R1, R1, T0, N); + carry += Add(R1, R1, T0, N); + Increment(R3, N2, carry); + } +} + +// R[N] - bottom half of A*B +// T[3*N/2] - temporary work space +// A[N] - multiplier +// B[N] - multiplicant + +void RecursiveMultiplyBottom(word *R, word *T, const word *A, const word *B, size_t N) +{ + assert(N>=2 && N%2==0); + + if (N <= s_recursionLimit) + s_pBot[N/4](R, A, B); + else + { + const size_t N2 = N/2; + + RecursiveMultiply(R, T, A0, B0, N2); + RecursiveMultiplyBottom(T0, T1, A1, B0, N2); + Add(R1, R1, T0, N2); + RecursiveMultiplyBottom(T0, T1, A0, B1, N2); + Add(R1, R1, T0, N2); + } +} + +// R[N] --- upper half of A*B +// T[2*N] - temporary work space +// L[N] --- lower half of A*B +// A[N] --- multiplier +// B[N] --- multiplicant + +void MultiplyTop(word *R, word *T, const word *L, const word *A, const word *B, size_t N) +{ + assert(N>=2 && N%2==0); + + if (N <= s_recursionLimit) + s_pTop[N/4](R, A, B, L[N-1]); + else + { + const size_t N2 = N/2; + + size_t AN2 = Compare(A0, A1, N2) > 0 ? 0 : N2; + Subtract(R0, A + AN2, A + (N2 ^ AN2), N2); + + size_t BN2 = Compare(B0, B1, N2) > 0 ? 0 : N2; + Subtract(R1, B + BN2, B + (N2 ^ BN2), N2); + + RecursiveMultiply(T0, T2, R0, R1, N2); + RecursiveMultiply(R0, T2, A1, B1, N2); + + // now T[01] holds (A1-A0)*(B0-B1) = A1*B0+A0*B1-A1*B1-A0*B0, R[01] holds A1*B1 + + int t, c3; + int c2 = Subtract(T2, L+N2, L, N2); + + if (AN2 == BN2) + { + c2 -= Add(T2, T2, T0, N2); + t = (Compare(T2, R0, N2) == -1); + c3 = t - Subtract(T2, T2, T1, N2); + } + else + { + c2 += Subtract(T2, T2, T0, N2); + t = (Compare(T2, R0, N2) == -1); + c3 = t + Add(T2, T2, T1, N2); + } + + c2 += t; + if (c2 >= 0) + c3 += Increment(T2, N2, c2); + else + c3 -= Decrement(T2, N2, -c2); + c3 += Add(R0, T2, R1, N2); + + assert (c3 >= 0 && c3 <= 2); + Increment(R1, N2, c3); + } +} + +inline void Multiply(word *R, word *T, const word *A, const word *B, size_t N) +{ + RecursiveMultiply(R, T, A, B, N); +} + +inline void Square(word *R, word *T, const word *A, size_t N) +{ + RecursiveSquare(R, T, A, N); +} + +inline void MultiplyBottom(word *R, word *T, const word *A, const word *B, size_t N) +{ + RecursiveMultiplyBottom(R, T, A, B, N); +} + +// R[NA+NB] - result = A*B +// T[NA+NB] - temporary work space +// A[NA] ---- multiplier +// B[NB] ---- multiplicant + +void AsymmetricMultiply(word *R, word *T, const word *A, size_t NA, const word *B, size_t NB) +{ + if (NA == NB) + { + if (A == B) + Square(R, T, A, NA); + else + Multiply(R, T, A, B, NA); + + return; + } + + if (NA > NB) + { + std::swap(A, B); + std::swap(NA, NB); + } + + assert(NB % NA == 0); + + if (NA==2 && !A[1]) + { + switch (A[0]) + { + case 0: + SetWords(R, 0, NB+2); + return; + case 1: + CopyWords(R, B, NB); + R[NB] = R[NB+1] = 0; + return; + default: + R[NB] = LinearMultiply(R, B, A[0], NB); + R[NB+1] = 0; + return; + } + } + + size_t i; + if ((NB/NA)%2 == 0) + { + Multiply(R, T, A, B, NA); + CopyWords(T+2*NA, R+NA, NA); + + for (i=2*NA; i=4); + +#define M0 M +#define M1 (M+N2) +#define V0 V +#define V1 (V+N2) + +#define X0 X +#define X1 (X+N2) +#define X2 (X+N) +#define X3 (X+N+N2) + + const size_t N2 = N/2; + Multiply(T0, T2, V0, X3, N2); + int c2 = Add(T0, T0, X0, N); + MultiplyBottom(T3, T2, T0, U, N2); + MultiplyTop(T2, R, T0, T3, M0, N2); + c2 -= Subtract(T2, T1, T2, N2); + Multiply(T0, R, T3, M1, N2); + c2 -= Subtract(T0, T2, T0, N2); + int c3 = -(int)Subtract(T1, X2, T1, N2); + Multiply(R0, T2, V1, X3, N2); + c3 += Add(R, R, T, N); + + if (c2>0) + c3 += Increment(R1, N2); + else if (c2<0) + c3 -= Decrement(R1, N2, -c2); + + assert(c3>=-1 && c3<=1); + if (c3>0) + Subtract(R, R, M, N); + else if (c3<0) + Add(R, R, M, N); + +#undef M0 +#undef M1 +#undef V0 +#undef V1 + +#undef X0 +#undef X1 +#undef X2 +#undef X3 +} + +#undef A0 +#undef A1 +#undef B0 +#undef B1 + +#undef T0 +#undef T1 +#undef T2 +#undef T3 + +#undef R0 +#undef R1 +#undef R2 +#undef R3 + +/* +// do a 3 word by 2 word divide, returns quotient and leaves remainder in A +static word SubatomicDivide(word *A, word B0, word B1) +{ + // assert {A[2],A[1]} < {B1,B0}, so quotient can fit in a word + assert(A[2] < B1 || (A[2]==B1 && A[1] < B0)); + + // estimate the quotient: do a 2 word by 1 word divide + word Q; + if (B1+1 == 0) + Q = A[2]; + else + Q = DWord(A[1], A[2]).DividedBy(B1+1); + + // now subtract Q*B from A + DWord p = DWord::Multiply(B0, Q); + DWord u = (DWord) A[0] - p.GetLowHalf(); + A[0] = u.GetLowHalf(); + u = (DWord) A[1] - p.GetHighHalf() - u.GetHighHalfAsBorrow() - DWord::Multiply(B1, Q); + A[1] = u.GetLowHalf(); + A[2] += u.GetHighHalf(); + + // Q <= actual quotient, so fix it + while (A[2] || A[1] > B1 || (A[1]==B1 && A[0]>=B0)) + { + u = (DWord) A[0] - B0; + A[0] = u.GetLowHalf(); + u = (DWord) A[1] - B1 - u.GetHighHalfAsBorrow(); + A[1] = u.GetLowHalf(); + A[2] += u.GetHighHalf(); + Q++; + assert(Q); // shouldn't overflow + } + + return Q; +} + +// do a 4 word by 2 word divide, returns 2 word quotient in Q0 and Q1 +static inline void AtomicDivide(word *Q, const word *A, const word *B) +{ + if (!B[0] && !B[1]) // if divisor is 0, we assume divisor==2**(2*WORD_BITS) + { + Q[0] = A[2]; + Q[1] = A[3]; + } + else + { + word T[4]; + T[0] = A[0]; T[1] = A[1]; T[2] = A[2]; T[3] = A[3]; + Q[1] = SubatomicDivide(T+1, B[0], B[1]); + Q[0] = SubatomicDivide(T, B[0], B[1]); + +#ifndef NDEBUG + // multiply quotient and divisor and add remainder, make sure it equals dividend + assert(!T[2] && !T[3] && (T[1] < B[1] || (T[1]==B[1] && T[0](T, DWord(A[0], A[1]), DWord(A[2], A[3]), DWord(B[0], B[1])); + Q[0] = q.GetLowHalf(); + Q[1] = q.GetHighHalf(); + +#ifndef NDEBUG + if (B[0] || B[1]) + { + // multiply quotient and divisor and add remainder, make sure it equals dividend + assert(!T[2] && !T[3] && (T[1] < B[1] || (T[1]==B[1] && T[0]= 0) + { + R[N] -= Subtract(R, R, B, N); + Q[1] += (++Q[0]==0); + assert(Q[0] || Q[1]); // no overflow + } +} + +// R[NB] -------- remainder = A%B +// Q[NA-NB+2] --- quotient = A/B +// T[NA+3*(NB+2)] - temp work space +// A[NA] -------- dividend +// B[NB] -------- divisor + +void Divide(word *R, word *Q, word *T, const word *A, size_t NA, const word *B, size_t NB) +{ + assert(NA && NB && NA%2==0 && NB%2==0); + assert(B[NB-1] || B[NB-2]); + assert(NB <= NA); + + // set up temporary work space + word *const TA=T; + word *const TB=T+NA+2; + word *const TP=T+NA+2+NB; + + // copy B into TB and normalize it so that TB has highest bit set to 1 + unsigned shiftWords = (B[NB-1]==0); + TB[0] = TB[NB-1] = 0; + CopyWords(TB+shiftWords, B, NB-shiftWords); + unsigned shiftBits = WORD_BITS - BitPrecision(TB[NB-1]); + assert(shiftBits < WORD_BITS); + ShiftWordsLeftByBits(TB, NB, shiftBits); + + // copy A into TA and normalize it + TA[0] = TA[NA] = TA[NA+1] = 0; + CopyWords(TA+shiftWords, A, NA); + ShiftWordsLeftByBits(TA, NA+2, shiftBits); + + if (TA[NA+1]==0 && TA[NA] <= 1) + { + Q[NA-NB+1] = Q[NA-NB] = 0; + while (TA[NA] || Compare(TA+NA-NB, TB, NB) >= 0) + { + TA[NA] -= Subtract(TA+NA-NB, TA+NA-NB, TB, NB); + ++Q[NA-NB]; + } + } + else + { + NA+=2; + assert(Compare(TA+NA-NB, TB, NB) < 0); + } + + word BT[2]; + BT[0] = TB[NB-2] + 1; + BT[1] = TB[NB-1] + (BT[0]==0); + + // start reducing TA mod TB, 2 words at a time + for (size_t i=NA-2; i>=NB; i-=2) + { + AtomicDivide(Q+i-NB, TA+i-2, BT); + CorrectQuotientEstimate(TA+i-NB, TP, Q+i-NB, TB, NB); + } + + // copy TA into R, and denormalize it + CopyWords(R, TA+shiftWords, NB); + ShiftWordsRightByBits(R, NB, shiftBits); +} + +static inline size_t EvenWordCount(const word *X, size_t N) +{ + while (N && X[N-2]==0 && X[N-1]==0) + N-=2; + return N; +} + +// return k +// R[N] --- result = A^(-1) * 2^k mod M +// T[4*N] - temporary work space +// A[NA] -- number to take inverse of +// M[N] --- modulus + +unsigned int AlmostInverse(word *R, word *T, const word *A, size_t NA, const word *M, size_t N) +{ + assert(NA<=N && N && N%2==0); + + word *b = T; + word *c = T+N; + word *f = T+2*N; + word *g = T+3*N; + size_t bcLen=2, fgLen=EvenWordCount(M, N); + unsigned int k=0; + bool s=false; + + SetWords(T, 0, 3*N); + b[0]=1; + CopyWords(f, A, NA); + CopyWords(g, M, N); + + while (1) + { + word t=f[0]; + while (!t) + { + if (EvenWordCount(f, fgLen)==0) + { + SetWords(R, 0, N); + return 0; + } + + ShiftWordsRightByWords(f, fgLen, 1); + bcLen += 2 * (c[bcLen-1] != 0); + assert(bcLen <= N); + ShiftWordsLeftByWords(c, bcLen, 1); + k+=WORD_BITS; + t=f[0]; + } + + unsigned int i = TrailingZeros(t); + t >>= i; + k += i; + + if (t==1 && f[1]==0 && EvenWordCount(f+2, fgLen-2)==0) + { + if (s) + Subtract(R, M, b, N); + else + CopyWords(R, b, N); + return k; + } + + ShiftWordsRightByBits(f, fgLen, i); + t = ShiftWordsLeftByBits(c, bcLen, i); + c[bcLen] += t; + bcLen += 2 * (t!=0); + assert(bcLen <= N); + + bool swap = Compare(f, g, fgLen)==-1; + ConditionalSwapPointers(swap, f, g); + ConditionalSwapPointers(swap, b, c); + s ^= swap; + + fgLen -= 2 * !(f[fgLen-2] | f[fgLen-1]); + + Subtract(f, f, g, fgLen); + t = Add(b, b, c, bcLen); + b[bcLen] += t; + bcLen += 2*t; + assert(bcLen <= N); + } +} + +// R[N] - result = A/(2^k) mod M +// A[N] - input +// M[N] - modulus + +void DivideByPower2Mod(word *R, const word *A, size_t k, const word *M, size_t N) +{ + CopyWords(R, A, N); + + while (k--) + { + if (R[0]%2==0) + ShiftWordsRightByBits(R, N, 1); + else + { + word carry = Add(R, R, M, N); + ShiftWordsRightByBits(R, N, 1); + R[N-1] += carry<<(WORD_BITS-1); + } + } +} + +// R[N] - result = A*(2^k) mod M +// A[N] - input +// M[N] - modulus + +void MultiplyByPower2Mod(word *R, const word *A, size_t k, const word *M, size_t N) +{ + CopyWords(R, A, N); + + while (k--) + if (ShiftWordsLeftByBits(R, N, 1) || Compare(R, M, N)>=0) + Subtract(R, R, M, N); +} + +// ****************************************************************** + +InitializeInteger::InitializeInteger() +{ + if (!g_pAssignIntToInteger) + { + SetFunctionPointers(); + g_pAssignIntToInteger = AssignIntToInteger; + } +} + +static const unsigned int RoundupSizeTable[] = {2, 2, 2, 4, 4, 8, 8, 8, 8}; + +static inline size_t RoundupSize(size_t n) +{ + if (n<=8) + return RoundupSizeTable[n]; + else if (n<=16) + return 16; + else if (n<=32) + return 32; + else if (n<=64) + return 64; + else return size_t(1) << BitPrecision(n-1); +} + +Integer::Integer() + : reg(2), sign(POSITIVE) +{ + reg[0] = reg[1] = 0; +} + +Integer::Integer(const Integer& t) + : reg(RoundupSize(t.WordCount())), sign(t.sign) +{ + CopyWords(reg, t.reg, reg.size()); +} + +Integer::Integer(Sign s, lword value) + : reg(2), sign(s) +{ + reg[0] = word(value); + reg[1] = word(SafeRightShift(value)); +} + +Integer::Integer(signed long value) + : reg(2) +{ + if (value >= 0) + sign = POSITIVE; + else + { + sign = NEGATIVE; + value = -value; + } + reg[0] = word(value); + reg[1] = word(SafeRightShift((unsigned long)value)); +} + +Integer::Integer(Sign s, word high, word low) + : reg(2), sign(s) +{ + reg[0] = low; + reg[1] = high; +} + +bool Integer::IsConvertableToLong() const +{ + if (ByteCount() > sizeof(long)) + return false; + + unsigned long value = (unsigned long)reg[0]; + value += SafeLeftShift((unsigned long)reg[1]); + + if (sign==POSITIVE) + return (signed long)value >= 0; + else + return -(signed long)value < 0; +} + +signed long Integer::ConvertToLong() const +{ + assert(IsConvertableToLong()); + + unsigned long value = (unsigned long)reg[0]; + value += SafeLeftShift((unsigned long)reg[1]); + return sign==POSITIVE ? value : -(signed long)value; +} + +Integer::Integer(BufferedTransformation &encodedInteger, size_t byteCount, Signedness s) +{ + Decode(encodedInteger, byteCount, s); +} + +Integer::Integer(const byte *encodedInteger, size_t byteCount, Signedness s) +{ + Decode(encodedInteger, byteCount, s); +} + +Integer::Integer(BufferedTransformation &bt) +{ + BERDecode(bt); +} + +Integer::Integer(RandomNumberGenerator &rng, size_t bitcount) +{ + Randomize(rng, bitcount); +} + +Integer::Integer(RandomNumberGenerator &rng, const Integer &min, const Integer &max, RandomNumberType rnType, const Integer &equiv, const Integer &mod) +{ + if (!Randomize(rng, min, max, rnType, equiv, mod)) + throw Integer::RandomNumberNotFound(); +} + +Integer Integer::Power2(size_t e) +{ + Integer r((word)0, BitsToWords(e+1)); + r.SetBit(e); + return r; +} + +template +struct NewInteger +{ + Integer * operator()() const + { + return new Integer(i); + } +}; + +const Integer &Integer::Zero() +{ + return Singleton().Ref(); +} + +const Integer &Integer::One() +{ + return Singleton >().Ref(); +} + +const Integer &Integer::Two() +{ + return Singleton >().Ref(); +} + +bool Integer::operator!() const +{ + return IsNegative() ? false : (reg[0]==0 && WordCount()==0); +} + +Integer& Integer::operator=(const Integer& t) +{ + if (this != &t) + { + if (reg.size() != t.reg.size() || t.reg[t.reg.size()/2] == 0) + reg.New(RoundupSize(t.WordCount())); + CopyWords(reg, t.reg, reg.size()); + sign = t.sign; + } + return *this; +} + +bool Integer::GetBit(size_t n) const +{ + if (n/WORD_BITS >= reg.size()) + return 0; + else + return bool((reg[n/WORD_BITS] >> (n % WORD_BITS)) & 1); +} + +void Integer::SetBit(size_t n, bool value) +{ + if (value) + { + reg.CleanGrow(RoundupSize(BitsToWords(n+1))); + reg[n/WORD_BITS] |= (word(1) << (n%WORD_BITS)); + } + else + { + if (n/WORD_BITS < reg.size()) + reg[n/WORD_BITS] &= ~(word(1) << (n%WORD_BITS)); + } +} + +byte Integer::GetByte(size_t n) const +{ + if (n/WORD_SIZE >= reg.size()) + return 0; + else + return byte(reg[n/WORD_SIZE] >> ((n%WORD_SIZE)*8)); +} + +void Integer::SetByte(size_t n, byte value) +{ + reg.CleanGrow(RoundupSize(BytesToWords(n+1))); + reg[n/WORD_SIZE] &= ~(word(0xff) << 8*(n%WORD_SIZE)); + reg[n/WORD_SIZE] |= (word(value) << 8*(n%WORD_SIZE)); +} + +lword Integer::GetBits(size_t i, size_t n) const +{ + lword v = 0; + assert(n <= sizeof(v)*8); + for (unsigned int j=0; j +static Integer StringToInteger(const T *str) +{ + int radix; + // GCC workaround + // std::char_traits::length() not defined in GCC 3.2 and STLport 4.5.3 + unsigned int length; + for (length = 0; str[length] != 0; length++) {} + + Integer v; + + if (length == 0) + return v; + + switch (str[length-1]) + { + case 'h': + case 'H': + radix=16; + break; + case 'o': + case 'O': + radix=8; + break; + case 'b': + case 'B': + radix=2; + break; + default: + radix=10; + } + + if (length > 2 && str[0] == '0' && str[1] == 'x') + radix = 16; + + for (unsigned i=0; i= '0' && str[i] <= '9') + digit = str[i] - '0'; + else if (str[i] >= 'A' && str[i] <= 'F') + digit = str[i] - 'A' + 10; + else if (str[i] >= 'a' && str[i] <= 'f') + digit = str[i] - 'a' + 10; + else + digit = radix; + + if (digit < radix) + { + v *= radix; + v += digit; + } + } + + if (str[0] == '-') + v.Negate(); + + return v; +} + +Integer::Integer(const char *str) + : reg(2), sign(POSITIVE) +{ + *this = StringToInteger(str); +} + +Integer::Integer(const wchar_t *str) + : reg(2), sign(POSITIVE) +{ + *this = StringToInteger(str); +} + +unsigned int Integer::WordCount() const +{ + return (unsigned int)CountWords(reg, reg.size()); +} + +unsigned int Integer::ByteCount() const +{ + unsigned wordCount = WordCount(); + if (wordCount) + return (wordCount-1)*WORD_SIZE + BytePrecision(reg[wordCount-1]); + else + return 0; +} + +unsigned int Integer::BitCount() const +{ + unsigned wordCount = WordCount(); + if (wordCount) + return (wordCount-1)*WORD_BITS + BitPrecision(reg[wordCount-1]); + else + return 0; +} + +void Integer::Decode(const byte *input, size_t inputLen, Signedness s) +{ + StringStore store(input, inputLen); + Decode(store, inputLen, s); +} + +void Integer::Decode(BufferedTransformation &bt, size_t inputLen, Signedness s) +{ + assert(bt.MaxRetrievable() >= inputLen); + + byte b; + bt.Peek(b); + sign = ((s==SIGNED) && (b & 0x80)) ? NEGATIVE : POSITIVE; + + while (inputLen>0 && (sign==POSITIVE ? b==0 : b==0xff)) + { + bt.Skip(1); + inputLen--; + bt.Peek(b); + } + + reg.CleanNew(RoundupSize(BytesToWords(inputLen))); + + for (size_t i=inputLen; i > 0; i--) + { + bt.Get(b); + reg[(i-1)/WORD_SIZE] |= word(b) << ((i-1)%WORD_SIZE)*8; + } + + if (sign == NEGATIVE) + { + for (size_t i=inputLen; i 0; i--) + bt.Put(GetByte(i-1)); + } + else + { + // take two's complement of *this + Integer temp = Integer::Power2(8*STDMAX((size_t)ByteCount(), outputLen)) + *this; + temp.Encode(bt, outputLen, UNSIGNED); + } +} + +void Integer::DEREncode(BufferedTransformation &bt) const +{ + DERGeneralEncoder enc(bt, INTEGER); + Encode(enc, MinEncodedSize(SIGNED), SIGNED); + enc.MessageEnd(); +} + +void Integer::BERDecode(const byte *input, size_t len) +{ + StringStore store(input, len); + BERDecode(store); +} + +void Integer::BERDecode(BufferedTransformation &bt) +{ + BERGeneralDecoder dec(bt, INTEGER); + if (!dec.IsDefiniteLength() || dec.MaxRetrievable() < dec.RemainingLength()) + BERDecodeError(); + Decode(dec, (size_t)dec.RemainingLength(), SIGNED); + dec.MessageEnd(); +} + +void Integer::DEREncodeAsOctetString(BufferedTransformation &bt, size_t length) const +{ + DERGeneralEncoder enc(bt, OCTET_STRING); + Encode(enc, length); + enc.MessageEnd(); +} + +void Integer::BERDecodeAsOctetString(BufferedTransformation &bt, size_t length) +{ + BERGeneralDecoder dec(bt, OCTET_STRING); + if (!dec.IsDefiniteLength() || dec.RemainingLength() != length) + BERDecodeError(); + Decode(dec, length); + dec.MessageEnd(); +} + +size_t Integer::OpenPGPEncode(byte *output, size_t len) const +{ + ArraySink sink(output, len); + return OpenPGPEncode(sink); +} + +size_t Integer::OpenPGPEncode(BufferedTransformation &bt) const +{ + word16 bitCount = BitCount(); + bt.PutWord16(bitCount); + size_t byteCount = BitsToBytes(bitCount); + Encode(bt, byteCount); + return 2 + byteCount; +} + +void Integer::OpenPGPDecode(const byte *input, size_t len) +{ + StringStore store(input, len); + OpenPGPDecode(store); +} + +void Integer::OpenPGPDecode(BufferedTransformation &bt) +{ + word16 bitCount; + if (bt.GetWord16(bitCount) != 2 || bt.MaxRetrievable() < BitsToBytes(bitCount)) + throw OpenPGPDecodeErr(); + Decode(bt, BitsToBytes(bitCount)); +} + +void Integer::Randomize(RandomNumberGenerator &rng, size_t nbits) +{ + const size_t nbytes = nbits/8 + 1; + SecByteBlock buf(nbytes); + rng.GenerateBlock(buf, nbytes); + if (nbytes) + buf[0] = (byte)Crop(buf[0], nbits % 8); + Decode(buf, nbytes, UNSIGNED); +} + +void Integer::Randomize(RandomNumberGenerator &rng, const Integer &min, const Integer &max) +{ + if (min > max) + throw InvalidArgument("Integer: Min must be no greater than Max"); + + Integer range = max - min; + const unsigned int nbits = range.BitCount(); + + do + { + Randomize(rng, nbits); + } + while (*this > range); + + *this += min; +} + +bool Integer::Randomize(RandomNumberGenerator &rng, const Integer &min, const Integer &max, RandomNumberType rnType, const Integer &equiv, const Integer &mod) +{ + return GenerateRandomNoThrow(rng, MakeParameters("Min", min)("Max", max)("RandomNumberType", rnType)("EquivalentTo", equiv)("Mod", mod)); +} + +class KDF2_RNG : public RandomNumberGenerator +{ +public: + KDF2_RNG(const byte *seed, size_t seedSize) + : m_counter(0), m_counterAndSeed(seedSize + 4) + { + memcpy(m_counterAndSeed + 4, seed, seedSize); + } + + void GenerateBlock(byte *output, size_t size) + { + PutWord(false, BIG_ENDIAN_ORDER, m_counterAndSeed, m_counter); + ++m_counter; + P1363_KDF2::DeriveKey(output, size, m_counterAndSeed, m_counterAndSeed.size(), NULL, 0); + } + +private: + word32 m_counter; + SecByteBlock m_counterAndSeed; +}; + +bool Integer::GenerateRandomNoThrow(RandomNumberGenerator &i_rng, const NameValuePairs ¶ms) +{ + Integer min = params.GetValueWithDefault("Min", Integer::Zero()); + Integer max; + if (!params.GetValue("Max", max)) + { + int bitLength; + if (params.GetIntValue("BitLength", bitLength)) + max = Integer::Power2(bitLength); + else + throw InvalidArgument("Integer: missing Max argument"); + } + if (min > max) + throw InvalidArgument("Integer: Min must be no greater than Max"); + + Integer equiv = params.GetValueWithDefault("EquivalentTo", Integer::Zero()); + Integer mod = params.GetValueWithDefault("Mod", Integer::One()); + + if (equiv.IsNegative() || equiv >= mod) + throw InvalidArgument("Integer: invalid EquivalentTo and/or Mod argument"); + + Integer::RandomNumberType rnType = params.GetValueWithDefault("RandomNumberType", Integer::ANY); + + member_ptr kdf2Rng; + ConstByteArrayParameter seed; + if (params.GetValue(Name::Seed(), seed)) + { + ByteQueue bq; + DERSequenceEncoder seq(bq); + min.DEREncode(seq); + max.DEREncode(seq); + equiv.DEREncode(seq); + mod.DEREncode(seq); + DEREncodeUnsigned(seq, rnType); + DEREncodeOctetString(seq, seed.begin(), seed.size()); + seq.MessageEnd(); + + SecByteBlock finalSeed((size_t)bq.MaxRetrievable()); + bq.Get(finalSeed, finalSeed.size()); + kdf2Rng.reset(new KDF2_RNG(finalSeed.begin(), finalSeed.size())); + } + RandomNumberGenerator &rng = kdf2Rng.get() ? (RandomNumberGenerator &)*kdf2Rng : i_rng; + + switch (rnType) + { + case ANY: + if (mod == One()) + Randomize(rng, min, max); + else + { + Integer min1 = min + (equiv-min)%mod; + if (max < min1) + return false; + Randomize(rng, Zero(), (max - min1) / mod); + *this *= mod; + *this += min1; + } + return true; + + case PRIME: + { + const PrimeSelector *pSelector = params.GetValueWithDefault(Name::PointerToPrimeSelector(), (const PrimeSelector *)NULL); + + int i; + i = 0; + while (1) + { + if (++i==16) + { + // check if there are any suitable primes in [min, max] + Integer first = min; + if (FirstPrime(first, max, equiv, mod, pSelector)) + { + // if there is only one suitable prime, we're done + *this = first; + if (!FirstPrime(first, max, equiv, mod, pSelector)) + return true; + } + else + return false; + } + + Randomize(rng, min, max); + if (FirstPrime(*this, STDMIN(*this+mod*PrimeSearchInterval(max), max), equiv, mod, pSelector)) + return true; + } + } + + default: + throw InvalidArgument("Integer: invalid RandomNumberType argument"); + } +} + +std::istream& operator>>(std::istream& in, Integer &a) +{ + char c; + unsigned int length = 0; + SecBlock str(length + 16); + + std::ws(in); + + do + { + in.read(&c, 1); + str[length++] = c; + if (length >= str.size()) + str.Grow(length + 16); + } + while (in && (c=='-' || c=='x' || (c>='0' && c<='9') || (c>='a' && c<='f') || (c>='A' && c<='F') || c=='h' || c=='H' || c=='o' || c=='O' || c==',' || c=='.')); + + if (in.gcount()) + in.putback(c); + str[length-1] = '\0'; + a = Integer(str); + + return in; +} + +std::ostream& operator<<(std::ostream& out, const Integer &a) +{ + // Get relevant conversion specifications from ostream. + long f = out.flags() & std::ios::basefield; // Get base digits. + int base, block; + char suffix; + switch(f) + { + case std::ios::oct : + base = 8; + block = 8; + suffix = 'o'; + break; + case std::ios::hex : + base = 16; + block = 4; + suffix = 'h'; + break; + default : + base = 10; + block = 3; + suffix = '.'; + } + + Integer temp1=a, temp2; + + if (a.IsNegative()) + { + out << '-'; + temp1.Negate(); + } + + if (!a) + out << '0'; + + static const char upper[]="0123456789ABCDEF"; + static const char lower[]="0123456789abcdef"; + + const char* vec = (out.flags() & std::ios::uppercase) ? upper : lower; + unsigned i=0; + SecBlock s(a.BitCount() / (BitPrecision(base)-1) + 1); + + while (!!temp1) + { + word digit; + Integer::Divide(digit, temp2, temp1, base); + s[i++]=vec[digit]; + temp1.swap(temp2); + } + + while (i--) + { + out << s[i]; +// if (i && !(i%block)) +// out << ","; + } + return out << suffix; +} + +Integer& Integer::operator++() +{ + if (NotNegative()) + { + if (Increment(reg, reg.size())) + { + reg.CleanGrow(2*reg.size()); + reg[reg.size()/2]=1; + } + } + else + { + word borrow = Decrement(reg, reg.size()); + assert(!borrow); + if (WordCount()==0) + *this = Zero(); + } + return *this; +} + +Integer& Integer::operator--() +{ + if (IsNegative()) + { + if (Increment(reg, reg.size())) + { + reg.CleanGrow(2*reg.size()); + reg[reg.size()/2]=1; + } + } + else + { + if (Decrement(reg, reg.size())) + *this = -One(); + } + return *this; +} + +void PositiveAdd(Integer &sum, const Integer &a, const Integer& b) +{ + int carry; + if (a.reg.size() == b.reg.size()) + carry = Add(sum.reg, a.reg, b.reg, a.reg.size()); + else if (a.reg.size() > b.reg.size()) + { + carry = Add(sum.reg, a.reg, b.reg, b.reg.size()); + CopyWords(sum.reg+b.reg.size(), a.reg+b.reg.size(), a.reg.size()-b.reg.size()); + carry = Increment(sum.reg+b.reg.size(), a.reg.size()-b.reg.size(), carry); + } + else + { + carry = Add(sum.reg, a.reg, b.reg, a.reg.size()); + CopyWords(sum.reg+a.reg.size(), b.reg+a.reg.size(), b.reg.size()-a.reg.size()); + carry = Increment(sum.reg+a.reg.size(), b.reg.size()-a.reg.size(), carry); + } + + if (carry) + { + sum.reg.CleanGrow(2*sum.reg.size()); + sum.reg[sum.reg.size()/2] = 1; + } + sum.sign = Integer::POSITIVE; +} + +void PositiveSubtract(Integer &diff, const Integer &a, const Integer& b) +{ + unsigned aSize = a.WordCount(); + aSize += aSize%2; + unsigned bSize = b.WordCount(); + bSize += bSize%2; + + if (aSize == bSize) + { + if (Compare(a.reg, b.reg, aSize) >= 0) + { + Subtract(diff.reg, a.reg, b.reg, aSize); + diff.sign = Integer::POSITIVE; + } + else + { + Subtract(diff.reg, b.reg, a.reg, aSize); + diff.sign = Integer::NEGATIVE; + } + } + else if (aSize > bSize) + { + word borrow = Subtract(diff.reg, a.reg, b.reg, bSize); + CopyWords(diff.reg+bSize, a.reg+bSize, aSize-bSize); + borrow = Decrement(diff.reg+bSize, aSize-bSize, borrow); + assert(!borrow); + diff.sign = Integer::POSITIVE; + } + else + { + word borrow = Subtract(diff.reg, b.reg, a.reg, aSize); + CopyWords(diff.reg+aSize, b.reg+aSize, bSize-aSize); + borrow = Decrement(diff.reg+aSize, bSize-aSize, borrow); + assert(!borrow); + diff.sign = Integer::NEGATIVE; + } +} + +// MSVC .NET 2003 workaround +template inline const T& STDMAX2(const T& a, const T& b) +{ + return a < b ? b : a; +} + +Integer Integer::Plus(const Integer& b) const +{ + Integer sum((word)0, STDMAX2(reg.size(), b.reg.size())); + if (NotNegative()) + { + if (b.NotNegative()) + PositiveAdd(sum, *this, b); + else + PositiveSubtract(sum, *this, b); + } + else + { + if (b.NotNegative()) + PositiveSubtract(sum, b, *this); + else + { + PositiveAdd(sum, *this, b); + sum.sign = Integer::NEGATIVE; + } + } + return sum; +} + +Integer& Integer::operator+=(const Integer& t) +{ + reg.CleanGrow(t.reg.size()); + if (NotNegative()) + { + if (t.NotNegative()) + PositiveAdd(*this, *this, t); + else + PositiveSubtract(*this, *this, t); + } + else + { + if (t.NotNegative()) + PositiveSubtract(*this, t, *this); + else + { + PositiveAdd(*this, *this, t); + sign = Integer::NEGATIVE; + } + } + return *this; +} + +Integer Integer::Minus(const Integer& b) const +{ + Integer diff((word)0, STDMAX2(reg.size(), b.reg.size())); + if (NotNegative()) + { + if (b.NotNegative()) + PositiveSubtract(diff, *this, b); + else + PositiveAdd(diff, *this, b); + } + else + { + if (b.NotNegative()) + { + PositiveAdd(diff, *this, b); + diff.sign = Integer::NEGATIVE; + } + else + PositiveSubtract(diff, b, *this); + } + return diff; +} + +Integer& Integer::operator-=(const Integer& t) +{ + reg.CleanGrow(t.reg.size()); + if (NotNegative()) + { + if (t.NotNegative()) + PositiveSubtract(*this, *this, t); + else + PositiveAdd(*this, *this, t); + } + else + { + if (t.NotNegative()) + { + PositiveAdd(*this, *this, t); + sign = Integer::NEGATIVE; + } + else + PositiveSubtract(*this, t, *this); + } + return *this; +} + +Integer& Integer::operator<<=(size_t n) +{ + const size_t wordCount = WordCount(); + const size_t shiftWords = n / WORD_BITS; + const unsigned int shiftBits = (unsigned int)(n % WORD_BITS); + + reg.CleanGrow(RoundupSize(wordCount+BitsToWords(n))); + ShiftWordsLeftByWords(reg, wordCount + shiftWords, shiftWords); + ShiftWordsLeftByBits(reg+shiftWords, wordCount+BitsToWords(shiftBits), shiftBits); + return *this; +} + +Integer& Integer::operator>>=(size_t n) +{ + const size_t wordCount = WordCount(); + const size_t shiftWords = n / WORD_BITS; + const unsigned int shiftBits = (unsigned int)(n % WORD_BITS); + + ShiftWordsRightByWords(reg, wordCount, shiftWords); + if (wordCount > shiftWords) + ShiftWordsRightByBits(reg, wordCount-shiftWords, shiftBits); + if (IsNegative() && WordCount()==0) // avoid -0 + *this = Zero(); + return *this; +} + +void PositiveMultiply(Integer &product, const Integer &a, const Integer &b) +{ + size_t aSize = RoundupSize(a.WordCount()); + size_t bSize = RoundupSize(b.WordCount()); + + product.reg.CleanNew(RoundupSize(aSize+bSize)); + product.sign = Integer::POSITIVE; + + IntegerSecBlock workspace(aSize + bSize); + AsymmetricMultiply(product.reg, workspace, a.reg, aSize, b.reg, bSize); +} + +void Multiply(Integer &product, const Integer &a, const Integer &b) +{ + PositiveMultiply(product, a, b); + + if (a.NotNegative() != b.NotNegative()) + product.Negate(); +} + +Integer Integer::Times(const Integer &b) const +{ + Integer product; + Multiply(product, *this, b); + return product; +} + +/* +void PositiveDivide(Integer &remainder, Integer "ient, + const Integer ÷nd, const Integer &divisor) +{ + remainder.reg.CleanNew(divisor.reg.size()); + remainder.sign = Integer::POSITIVE; + quotient.reg.New(0); + quotient.sign = Integer::POSITIVE; + unsigned i=dividend.BitCount(); + while (i--) + { + word overflow = ShiftWordsLeftByBits(remainder.reg, remainder.reg.size(), 1); + remainder.reg[0] |= dividend[i]; + if (overflow || remainder >= divisor) + { + Subtract(remainder.reg, remainder.reg, divisor.reg, remainder.reg.size()); + quotient.SetBit(i); + } + } +} +*/ + +void PositiveDivide(Integer &remainder, Integer "ient, + const Integer &a, const Integer &b) +{ + unsigned aSize = a.WordCount(); + unsigned bSize = b.WordCount(); + + if (!bSize) + throw Integer::DivideByZero(); + + if (aSize < bSize) + { + remainder = a; + remainder.sign = Integer::POSITIVE; + quotient = Integer::Zero(); + return; + } + + aSize += aSize%2; // round up to next even number + bSize += bSize%2; + + remainder.reg.CleanNew(RoundupSize(bSize)); + remainder.sign = Integer::POSITIVE; + quotient.reg.CleanNew(RoundupSize(aSize-bSize+2)); + quotient.sign = Integer::POSITIVE; + + IntegerSecBlock T(aSize+3*(bSize+2)); + Divide(remainder.reg, quotient.reg, T, a.reg, aSize, b.reg, bSize); +} + +void Integer::Divide(Integer &remainder, Integer "ient, const Integer ÷nd, const Integer &divisor) +{ + PositiveDivide(remainder, quotient, dividend, divisor); + + if (dividend.IsNegative()) + { + quotient.Negate(); + if (remainder.NotZero()) + { + --quotient; + remainder = divisor.AbsoluteValue() - remainder; + } + } + + if (divisor.IsNegative()) + quotient.Negate(); +} + +void Integer::DivideByPowerOf2(Integer &r, Integer &q, const Integer &a, unsigned int n) +{ + q = a; + q >>= n; + + const size_t wordCount = BitsToWords(n); + if (wordCount <= a.WordCount()) + { + r.reg.resize(RoundupSize(wordCount)); + CopyWords(r.reg, a.reg, wordCount); + SetWords(r.reg+wordCount, 0, r.reg.size()-wordCount); + if (n % WORD_BITS != 0) + r.reg[wordCount-1] %= (word(1) << (n % WORD_BITS)); + } + else + { + r.reg.resize(RoundupSize(a.WordCount())); + CopyWords(r.reg, a.reg, r.reg.size()); + } + r.sign = POSITIVE; + + if (a.IsNegative() && r.NotZero()) + { + --q; + r = Power2(n) - r; + } +} + +Integer Integer::DividedBy(const Integer &b) const +{ + Integer remainder, quotient; + Integer::Divide(remainder, quotient, *this, b); + return quotient; +} + +Integer Integer::Modulo(const Integer &b) const +{ + Integer remainder, quotient; + Integer::Divide(remainder, quotient, *this, b); + return remainder; +} + +void Integer::Divide(word &remainder, Integer "ient, const Integer ÷nd, word divisor) +{ + if (!divisor) + throw Integer::DivideByZero(); + + assert(divisor); + + if ((divisor & (divisor-1)) == 0) // divisor is a power of 2 + { + quotient = dividend >> (BitPrecision(divisor)-1); + remainder = dividend.reg[0] & (divisor-1); + return; + } + + unsigned int i = dividend.WordCount(); + quotient.reg.CleanNew(RoundupSize(i)); + remainder = 0; + while (i--) + { + quotient.reg[i] = DWord(dividend.reg[i], remainder) / divisor; + remainder = DWord(dividend.reg[i], remainder) % divisor; + } + + if (dividend.NotNegative()) + quotient.sign = POSITIVE; + else + { + quotient.sign = NEGATIVE; + if (remainder) + { + --quotient; + remainder = divisor - remainder; + } + } +} + +Integer Integer::DividedBy(word b) const +{ + word remainder; + Integer quotient; + Integer::Divide(remainder, quotient, *this, b); + return quotient; +} + +word Integer::Modulo(word divisor) const +{ + if (!divisor) + throw Integer::DivideByZero(); + + assert(divisor); + + word remainder; + + if ((divisor & (divisor-1)) == 0) // divisor is a power of 2 + remainder = reg[0] & (divisor-1); + else + { + unsigned int i = WordCount(); + + if (divisor <= 5) + { + DWord sum(0, 0); + while (i--) + sum += reg[i]; + remainder = sum % divisor; + } + else + { + remainder = 0; + while (i--) + remainder = DWord(reg[i], remainder) % divisor; + } + } + + if (IsNegative() && remainder) + remainder = divisor - remainder; + + return remainder; +} + +void Integer::Negate() +{ + if (!!(*this)) // don't flip sign if *this==0 + sign = Sign(1-sign); +} + +int Integer::PositiveCompare(const Integer& t) const +{ + unsigned size = WordCount(), tSize = t.WordCount(); + + if (size == tSize) + return CryptoPP::Compare(reg, t.reg, size); + else + return size > tSize ? 1 : -1; +} + +int Integer::Compare(const Integer& t) const +{ + if (NotNegative()) + { + if (t.NotNegative()) + return PositiveCompare(t); + else + return 1; + } + else + { + if (t.NotNegative()) + return -1; + else + return -PositiveCompare(t); + } +} + +Integer Integer::SquareRoot() const +{ + if (!IsPositive()) + return Zero(); + + // overestimate square root + Integer x, y = Power2((BitCount()+1)/2); + assert(y*y >= *this); + + do + { + x = y; + y = (x + *this/x) >> 1; + } while (y().Gcd(a, b); +} + +Integer Integer::InverseMod(const Integer &m) const +{ + assert(m.NotNegative()); + + if (IsNegative()) + return Modulo(m).InverseMod(m); + + if (m.IsEven()) + { + if (!m || IsEven()) + return Zero(); // no inverse + if (*this == One()) + return One(); + + Integer u = m.Modulo(*this).InverseMod(*this); + return !u ? Zero() : (m*(*this-u)+1)/(*this); + } + + SecBlock T(m.reg.size() * 4); + Integer r((word)0, m.reg.size()); + unsigned k = AlmostInverse(r.reg, T, reg, reg.size(), m.reg, m.reg.size()); + DivideByPower2Mod(r.reg, r.reg, k, m.reg, m.reg.size()); + return r; +} + +word Integer::InverseMod(word mod) const +{ + word g0 = mod, g1 = *this % mod; + word v0 = 0, v1 = 1; + word y; + + while (g1) + { + if (g1 == 1) + return v1; + y = g0 / g1; + g0 = g0 % g1; + v0 += y * v1; + + if (!g0) + break; + if (g0 == 1) + return mod-v0; + y = g1 / g0; + g1 = g1 % g0; + v1 += y * v0; + } + return 0; +} + +// ******************************************************** + +ModularArithmetic::ModularArithmetic(BufferedTransformation &bt) +{ + BERSequenceDecoder seq(bt); + OID oid(seq); + if (oid != ASN1::prime_field()) + BERDecodeError(); + m_modulus.BERDecode(seq); + seq.MessageEnd(); + m_result.reg.resize(m_modulus.reg.size()); +} + +void ModularArithmetic::DEREncode(BufferedTransformation &bt) const +{ + DERSequenceEncoder seq(bt); + ASN1::prime_field().DEREncode(seq); + m_modulus.DEREncode(seq); + seq.MessageEnd(); +} + +void ModularArithmetic::DEREncodeElement(BufferedTransformation &out, const Element &a) const +{ + a.DEREncodeAsOctetString(out, MaxElementByteLength()); +} + +void ModularArithmetic::BERDecodeElement(BufferedTransformation &in, Element &a) const +{ + a.BERDecodeAsOctetString(in, MaxElementByteLength()); +} + +const Integer& ModularArithmetic::Half(const Integer &a) const +{ + if (a.reg.size()==m_modulus.reg.size()) + { + CryptoPP::DivideByPower2Mod(m_result.reg.begin(), a.reg, 1, m_modulus.reg, a.reg.size()); + return m_result; + } + else + return m_result1 = (a.IsEven() ? (a >> 1) : ((a+m_modulus) >> 1)); +} + +const Integer& ModularArithmetic::Add(const Integer &a, const Integer &b) const +{ + if (a.reg.size()==m_modulus.reg.size() && b.reg.size()==m_modulus.reg.size()) + { + if (CryptoPP::Add(m_result.reg.begin(), a.reg, b.reg, a.reg.size()) + || Compare(m_result.reg, m_modulus.reg, a.reg.size()) >= 0) + { + CryptoPP::Subtract(m_result.reg.begin(), m_result.reg, m_modulus.reg, a.reg.size()); + } + return m_result; + } + else + { + m_result1 = a+b; + if (m_result1 >= m_modulus) + m_result1 -= m_modulus; + return m_result1; + } +} + +Integer& ModularArithmetic::Accumulate(Integer &a, const Integer &b) const +{ + if (a.reg.size()==m_modulus.reg.size() && b.reg.size()==m_modulus.reg.size()) + { + if (CryptoPP::Add(a.reg, a.reg, b.reg, a.reg.size()) + || Compare(a.reg, m_modulus.reg, a.reg.size()) >= 0) + { + CryptoPP::Subtract(a.reg, a.reg, m_modulus.reg, a.reg.size()); + } + } + else + { + a+=b; + if (a>=m_modulus) + a-=m_modulus; + } + + return a; +} + +const Integer& ModularArithmetic::Subtract(const Integer &a, const Integer &b) const +{ + if (a.reg.size()==m_modulus.reg.size() && b.reg.size()==m_modulus.reg.size()) + { + if (CryptoPP::Subtract(m_result.reg.begin(), a.reg, b.reg, a.reg.size())) + CryptoPP::Add(m_result.reg.begin(), m_result.reg, m_modulus.reg, a.reg.size()); + return m_result; + } + else + { + m_result1 = a-b; + if (m_result1.IsNegative()) + m_result1 += m_modulus; + return m_result1; + } +} + +Integer& ModularArithmetic::Reduce(Integer &a, const Integer &b) const +{ + if (a.reg.size()==m_modulus.reg.size() && b.reg.size()==m_modulus.reg.size()) + { + if (CryptoPP::Subtract(a.reg, a.reg, b.reg, a.reg.size())) + CryptoPP::Add(a.reg, a.reg, m_modulus.reg, a.reg.size()); + } + else + { + a-=b; + if (a.IsNegative()) + a+=m_modulus; + } + + return a; +} + +const Integer& ModularArithmetic::Inverse(const Integer &a) const +{ + if (!a) + return a; + + CopyWords(m_result.reg.begin(), m_modulus.reg, m_modulus.reg.size()); + if (CryptoPP::Subtract(m_result.reg.begin(), m_result.reg, a.reg, a.reg.size())) + Decrement(m_result.reg.begin()+a.reg.size(), m_modulus.reg.size()-a.reg.size()); + + return m_result; +} + +Integer ModularArithmetic::CascadeExponentiate(const Integer &x, const Integer &e1, const Integer &y, const Integer &e2) const +{ + if (m_modulus.IsOdd()) + { + MontgomeryRepresentation dr(m_modulus); + return dr.ConvertOut(dr.CascadeExponentiate(dr.ConvertIn(x), e1, dr.ConvertIn(y), e2)); + } + else + return AbstractRing::CascadeExponentiate(x, e1, y, e2); +} + +void ModularArithmetic::SimultaneousExponentiate(Integer *results, const Integer &base, const Integer *exponents, unsigned int exponentsCount) const +{ + if (m_modulus.IsOdd()) + { + MontgomeryRepresentation dr(m_modulus); + dr.SimultaneousExponentiate(results, dr.ConvertIn(base), exponents, exponentsCount); + for (unsigned int i=0; i::SimultaneousExponentiate(results, base, exponents, exponentsCount); +} + +MontgomeryRepresentation::MontgomeryRepresentation(const Integer &m) // modulus must be odd + : ModularArithmetic(m), + m_u((word)0, m_modulus.reg.size()), + m_workspace(5*m_modulus.reg.size()) +{ + if (!m_modulus.IsOdd()) + throw InvalidArgument("MontgomeryRepresentation: Montgomery representation requires an odd modulus"); + + RecursiveInverseModPower2(m_u.reg, m_workspace, m_modulus.reg, m_modulus.reg.size()); +} + +const Integer& MontgomeryRepresentation::Multiply(const Integer &a, const Integer &b) const +{ + word *const T = m_workspace.begin(); + word *const R = m_result.reg.begin(); + const size_t N = m_modulus.reg.size(); + assert(a.reg.size()<=N && b.reg.size()<=N); + + AsymmetricMultiply(T, T+2*N, a.reg, a.reg.size(), b.reg, b.reg.size()); + SetWords(T+a.reg.size()+b.reg.size(), 0, 2*N-a.reg.size()-b.reg.size()); + MontgomeryReduce(R, T+2*N, T, m_modulus.reg, m_u.reg, N); + return m_result; +} + +const Integer& MontgomeryRepresentation::Square(const Integer &a) const +{ + word *const T = m_workspace.begin(); + word *const R = m_result.reg.begin(); + const size_t N = m_modulus.reg.size(); + assert(a.reg.size()<=N); + + CryptoPP::Square(T, T+2*N, a.reg, a.reg.size()); + SetWords(T+2*a.reg.size(), 0, 2*N-2*a.reg.size()); + MontgomeryReduce(R, T+2*N, T, m_modulus.reg, m_u.reg, N); + return m_result; +} + +Integer MontgomeryRepresentation::ConvertOut(const Integer &a) const +{ + word *const T = m_workspace.begin(); + word *const R = m_result.reg.begin(); + const size_t N = m_modulus.reg.size(); + assert(a.reg.size()<=N); + + CopyWords(T, a.reg, a.reg.size()); + SetWords(T+a.reg.size(), 0, 2*N-a.reg.size()); + MontgomeryReduce(R, T+2*N, T, m_modulus.reg, m_u.reg, N); + return m_result; +} + +const Integer& MontgomeryRepresentation::MultiplicativeInverse(const Integer &a) const +{ +// return (EuclideanMultiplicativeInverse(a, modulus)<<(2*WORD_BITS*modulus.reg.size()))%modulus; + word *const T = m_workspace.begin(); + word *const R = m_result.reg.begin(); + const size_t N = m_modulus.reg.size(); + assert(a.reg.size()<=N); + + CopyWords(T, a.reg, a.reg.size()); + SetWords(T+a.reg.size(), 0, 2*N-a.reg.size()); + MontgomeryReduce(R, T+2*N, T, m_modulus.reg, m_u.reg, N); + unsigned k = AlmostInverse(R, T, R, N, m_modulus.reg, N); + +// cout << "k=" << k << " N*32=" << 32*N << endl; + + if (k>N*WORD_BITS) + DivideByPower2Mod(R, R, k-N*WORD_BITS, m_modulus.reg, N); + else + MultiplyByPower2Mod(R, R, N*WORD_BITS-k, m_modulus.reg, N); + + return m_result; +} + +NAMESPACE_END + +#endif -- cgit v1.2.3