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+/* Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA */
+
+/* based on Wei Dai's integer.cpp from CryptoPP */
+
+#include "runtime.hpp"
+#include "integer.hpp"
+#include "modarith.hpp"
+#include "asn.hpp"
+
+
+
+#ifdef __DECCXX
+ #include <c_asm.h> // for asm overflow assembly
+#endif
+
+#if defined(_M_X64) || defined(_M_IA64)
+ #include <intrin.h>
+#pragma intrinsic(_umul128)
+#endif
+
+
+#ifdef __GNUC__
+ #include <signal.h>
+ #include <setjmp.h>
+#endif
+
+
+#ifdef SSE2_INTRINSICS_AVAILABLE
+ #ifdef __GNUC__
+ #include <xmmintrin.h>
+ #ifdef TAOCRYPT_MEMALIGN_AVAILABLE
+ #include <malloc.h>
+ #else
+ #include <stdlib.h>
+ #endif
+ #else
+ #include <emmintrin.h>
+ #endif
+#elif defined(_MSC_VER) && defined(_M_IX86)
+/* #pragma message("You do not seem to have the Visual C++ Processor Pack ")
+ #pragma message("installed, so use of SSE2 intrinsics will be disabled.")
+*/
+ #pragma message("installed, so use of SSE2 intrinsics will be disabled.")
+#elif defined(__GNUC__) && defined(__i386__)
+/* #warning You do not have GCC 3.3 or later, or did not specify the -msse2 \
+ compiler option. Use of SSE2 intrinsics will be disabled.
+*/
+#endif
+
+
+namespace TaoCrypt {
+
+
+#ifdef SSE2_INTRINSICS_AVAILABLE
+
+template <class T>
+CPP_TYPENAME AlignedAllocator<T>::pointer AlignedAllocator<T>::allocate(
+ size_type n, const void *)
+{
+ if (n > this->max_size())
+ return 0;
+ if (n == 0)
+ return 0;
+ if (n >= 4)
+ {
+ void* p;
+ #ifdef TAOCRYPT_MM_MALLOC_AVAILABLE
+ p = _mm_malloc(sizeof(T)*n, 16);
+ #elif defined(TAOCRYPT_MEMALIGN_AVAILABLE)
+ p = memalign(16, sizeof(T)*n);
+ #elif defined(TAOCRYPT_MALLOC_ALIGNMENT_IS_16)
+ p = malloc(sizeof(T)*n);
+ #else
+ p = (byte *)malloc(sizeof(T)*n + 8);
+ // assume malloc alignment is at least 8
+ #endif
+
+ #ifdef TAOCRYPT_NO_ALIGNED_ALLOC
+ m_pBlock = p;
+ if (!IsAlignedOn(p, 16))
+ {
+ p = (byte *)p + 8;
+ }
+ #endif
+
+ return (T*)p;
+ }
+ return NEW_TC T[n];
+}
+
+
+template <class T>
+void AlignedAllocator<T>::deallocate(void* p, size_type n)
+{
+ memset(p, 0, n*sizeof(T));
+ if (n >= 4)
+ {
+ #ifdef TAOCRYPT_MM_MALLOC_AVAILABLE
+ _mm_free(p);
+ #elif defined(TAOCRYPT_NO_ALIGNED_ALLOC)
+ free(m_pBlock);
+ m_pBlock = 0;
+ #else
+ free(p);
+ #endif
+ }
+ else
+ tcArrayDelete((T *)p);
+}
+
+#endif // SSE2
+
+
+// ******** start of integer needs
+
+// start 5.2.1 adds DWord and Word ********
+
+// ********************************************************
+
+class DWord {
+public:
+DWord() {}
+
+#ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ explicit DWord(word low)
+ {
+ whole_ = low;
+ }
+#else
+ explicit DWord(word low)
+ {
+ halfs_.low = low;
+ halfs_.high = 0;
+ }
+#endif
+
+ DWord(word low, word high)
+ {
+ halfs_.low = low;
+ halfs_.high = high;
+ }
+
+ static DWord Multiply(word a, word b)
+ {
+ DWord r;
+
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ r.whole_ = (dword)a * b;
+
+ #elif defined(_M_X64) || defined(_M_IA64)
+ r.halfs_.low = _umul128(a, b, &r.halfs_.high);
+
+ #elif defined(__ia64__)
+ r.halfs_.low = a*b;
+ __asm__("xmpy.hu %0=%1,%2" : "=f" (r.halfs_.high)
+ : "f" (a), "f" (b));
+
+ #elif defined(_ARCH_PPC64)
+ r.halfs_.low = a*b;
+ __asm__("mulhdu %0,%1,%2" : "=r" (r.halfs_.high)
+ : "r" (a), "r" (b) : "cc");
+
+ #elif defined(__x86_64__)
+ __asm__("mulq %3" : "=d" (r.halfs_.high), "=a" (r.halfs_.low) :
+ "a" (a), "rm" (b) : "cc");
+
+ #elif defined(__mips64)
+ __asm__("dmultu %2,%3" : "=h" (r.halfs_.high), "=l" (r.halfs_.low)
+ : "r" (a), "r" (b));
+
+ #elif defined(_M_IX86)
+ // for testing
+ word64 t = (word64)a * b;
+ r.halfs_.high = ((word32 *)(&t))[1];
+ r.halfs_.low = (word32)t;
+ #else
+ #error can not implement DWord
+ #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 TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ whole_ = whole_ + a;
+ #else
+ halfs_.low += a;
+ halfs_.high += (halfs_.low < a);
+ #endif
+ return *this;
+ }
+
+ DWord operator+(word a)
+ {
+ DWord r;
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ r.whole_ = whole_ + a;
+ #else
+ r.halfs_.low = halfs_.low + a;
+ r.halfs_.high = halfs_.high + (r.halfs_.low < a);
+ #endif
+ return r;
+ }
+
+ DWord operator-(DWord a)
+ {
+ DWord r;
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ r.whole_ = whole_ - a.whole_;
+ #else
+ r.halfs_.low = halfs_.low - a.halfs_.low;
+ r.halfs_.high = halfs_.high - a.halfs_.high -
+ (r.halfs_.low > halfs_.low);
+ #endif
+ return r;
+ }
+
+ DWord operator-(word a)
+ {
+ DWord r;
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ r.whole_ = whole_ - a;
+ #else
+ r.halfs_.low = halfs_.low - a;
+ r.halfs_.high = halfs_.high - (r.halfs_.low > 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 TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ return !whole_;
+ #else
+ return !halfs_.high && !halfs_.low;
+ #endif
+ }
+
+ word GetLowHalf() const {return halfs_.low;}
+ word GetHighHalf() const {return halfs_.high;}
+ word GetHighHalfAsBorrow() const {return 0-halfs_.high;}
+
+private:
+ struct dword_struct
+ {
+ #ifdef LITTLE_ENDIAN_ORDER
+ word low;
+ word high;
+ #else
+ word high;
+ word low;
+ #endif
+ };
+
+ union
+ {
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ dword whole_;
+ #endif
+ struct dword_struct halfs_;
+ };
+};
+
+
+class Word {
+public:
+ Word() {}
+
+ Word(word value)
+ {
+ whole_ = value;
+ }
+
+ Word(hword low, hword high)
+ {
+ whole_ = low | (word(high) << (WORD_BITS/2));
+ }
+
+ static Word Multiply(hword a, hword b)
+ {
+ Word r;
+ r.whole_ = (word)a * b;
+ return r;
+ }
+
+ Word operator-(Word a)
+ {
+ Word r;
+ r.whole_ = whole_ - a.whole_;
+ return r;
+ }
+
+ Word operator-(hword a)
+ {
+ Word r;
+ r.whole_ = whole_ - a;
+ return r;
+ }
+
+ // returns quotient, which must fit in a word
+ hword operator/(hword divisor)
+ {
+ return hword(whole_ / divisor);
+ }
+
+ bool operator!() const
+ {
+ return !whole_;
+ }
+
+ word GetWhole() const {return whole_;}
+ hword GetLowHalf() const {return hword(whole_);}
+ hword GetHighHalf() const {return hword(whole_>>(WORD_BITS/2));}
+ hword GetHighHalfAsBorrow() const {return 0-hword(whole_>>(WORD_BITS/2));}
+
+private:
+ word whole_;
+};
+
+
+// dummy is VC60 compiler bug workaround
+// do a 3 word by 2 word divide, returns quotient and leaves remainder in A
+template <class S, class D>
+S DivideThreeWordsByTwo(S* A, S B0, S B1, D* dummy_VC6_WorkAround = 0)
+{
+ // estimate the quotient: do a 2 S by 1 S divide
+ S Q;
+ if (S(B1+1) == 0)
+ Q = A[2];
+ else
+ Q = D(A[1], A[2]) / S(B1+1);
+
+ // 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++;
+ }
+
+ return Q;
+}
+
+
+// do a 4 word by 2 word divide, returns 2 word quotient in Q0 and Q1
+template <class S, class D>
+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<S, D>(T+1, B.GetLowHalf(),
+ B.GetHighHalf());
+ Q[0] = DivideThreeWordsByTwo<S, D>(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 TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ return word(whole_ / a);
+ #else
+ hword r[4];
+ return DivideFourWordsByTwo<hword, Word>(r, halfs_.low,
+ halfs_.high, a).GetWhole();
+ #endif
+}
+
+inline word DWord::operator%(word a)
+{
+ #ifdef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+ return word(whole_ % a);
+ #else
+ if (a < (word(1) << (WORD_BITS/2)))
+ {
+ hword h = hword(a);
+ word r = halfs_.high % h;
+ r = ((halfs_.low >> (WORD_BITS/2)) + (r << (WORD_BITS/2))) % h;
+ return hword((hword(halfs_.low) + (r << (WORD_BITS/2))) % h);
+ }
+ else
+ {
+ hword r[4];
+ DivideFourWordsByTwo<hword, Word>(r, halfs_.low, halfs_.high, a);
+ return Word(r[0], r[1]).GetWhole();
+ }
+ #endif
+}
+
+
+
+// end 5.2.1 DWord and Word adds
+
+
+
+
+
+static const unsigned int RoundupSizeTable[] = {2, 2, 2, 4, 4, 8, 8, 8, 8};
+
+static inline unsigned int RoundupSize(unsigned int 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 1U << BitPrecision(n-1);
+}
+
+
+static int Compare(const word *A, const word *B, unsigned int N)
+{
+ while (N--)
+ if (A[N] > B[N])
+ return 1;
+ else if (A[N] < B[N])
+ return -1;
+
+ return 0;
+}
+
+static word Increment(word *A, unsigned int N, word B=1)
+{
+ word t = A[0];
+ A[0] = t+B;
+ if (A[0] >= t)
+ return 0;
+ for (unsigned i=1; i<N; i++)
+ if (++A[i])
+ return 0;
+ return 1;
+}
+
+static word Decrement(word *A, unsigned int N, word B=1)
+{
+ word t = A[0];
+ A[0] = t-B;
+ if (A[0] <= t)
+ return 0;
+ for (unsigned i=1; i<N; i++)
+ if (A[i]--)
+ return 0;
+ return 1;
+}
+
+static void TwosComplement(word *A, unsigned int N)
+{
+ Decrement(A, N);
+ for (unsigned i=0; i<N; i++)
+ A[i] = ~A[i];
+}
+
+
+static word LinearMultiply(word *C, const word *A, word B, unsigned int N)
+{
+ word carry=0;
+ for(unsigned i=0; i<N; i++)
+ {
+ DWord p = DWord::MultiplyAndAdd(A[i], B, carry);
+ C[i] = p.GetLowHalf();
+ carry = p.GetHighHalf();
+ }
+ return carry;
+}
+
+
+static word AtomicInverseModPower2(word A)
+{
+ word R=A%8;
+
+ for (unsigned i=3; i<WORD_BITS; i*=2)
+ R = R*(2-R*A);
+
+ return R;
+}
+
+
+// ********************************************************
+
+class Portable
+{
+public:
+ static word TAOCRYPT_CDECL Add(word *C, const word *A, const word *B,
+ unsigned int N);
+ static word TAOCRYPT_CDECL Subtract(word *C, const word *A, const word*B,
+ unsigned int N);
+ static void TAOCRYPT_CDECL Multiply2(word *C, const word *A, const word *B);
+ static word TAOCRYPT_CDECL Multiply2Add(word *C,
+ const word *A, const word *B);
+ static void TAOCRYPT_CDECL Multiply4(word *C, const word *A, const word *B);
+ static void TAOCRYPT_CDECL Multiply8(word *C, const word *A, const word *B);
+ static unsigned int TAOCRYPT_CDECL MultiplyRecursionLimit() {return 8;}
+
+ static void TAOCRYPT_CDECL Multiply2Bottom(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply4Bottom(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply8Bottom(word *C, const word *A,
+ const word *B);
+ static unsigned int TAOCRYPT_CDECL MultiplyBottomRecursionLimit(){return 8;}
+
+ static void TAOCRYPT_CDECL Square2(word *R, const word *A);
+ static void TAOCRYPT_CDECL Square4(word *R, const word *A);
+ static unsigned int TAOCRYPT_CDECL SquareRecursionLimit() {return 4;}
+};
+
+word Portable::Add(word *C, const word *A, const word *B, unsigned int N)
+{
+ DWord u(0, 0);
+ for (unsigned int i = 0; i < N; i+=2)
+ {
+ u = DWord(A[i]) + B[i] + u.GetHighHalf();
+ C[i] = u.GetLowHalf();
+ u = DWord(A[i+1]) + B[i+1] + u.GetHighHalf();
+ C[i+1] = u.GetLowHalf();
+ }
+ return u.GetHighHalf();
+}
+
+word Portable::Subtract(word *C, const word *A, const word *B, unsigned int N)
+{
+ DWord u(0, 0);
+ for (unsigned int i = 0; i < N; i+=2)
+ {
+ u = (DWord) A[i] - B[i] - u.GetHighHalfAsBorrow();
+ C[i] = u.GetLowHalf();
+ u = (DWord) A[i+1] - B[i+1] - u.GetHighHalfAsBorrow();
+ C[i+1] = u.GetLowHalf();
+ }
+ return 0-u.GetHighHalf();
+}
+
+void Portable::Multiply2(word *C, const word *A, const word *B)
+{
+/*
+ word s;
+ dword d;
+
+ if (A1 >= A0)
+ if (B0 >= B1)
+ {
+ s = 0;
+ d = (dword)(A1-A0)*(B0-B1);
+ }
+ else
+ {
+ s = (A1-A0);
+ d = (dword)s*(word)(B0-B1);
+ }
+ else
+ if (B0 > B1)
+ {
+ s = (B0-B1);
+ d = (word)(A1-A0)*(dword)s;
+ }
+ else
+ {
+ s = 0;
+ d = (dword)(A0-A1)*(B1-B0);
+ }
+*/
+ // this segment is the branchless equivalent of above
+ word D[4] = {A[1]-A[0], A[0]-A[1], B[0]-B[1], B[1]-B[0]};
+ unsigned int ai = A[1] < A[0];
+ unsigned int bi = B[0] < B[1];
+ unsigned int di = ai & bi;
+ DWord d = DWord::Multiply(D[di], D[di+2]);
+ D[1] = D[3] = 0;
+ unsigned int si = ai + !bi;
+ word s = D[si];
+
+ DWord A0B0 = DWord::Multiply(A[0], B[0]);
+ C[0] = A0B0.GetLowHalf();
+
+ DWord A1B1 = DWord::Multiply(A[1], B[1]);
+ DWord t = (DWord) A0B0.GetHighHalf() + A0B0.GetLowHalf() + d.GetLowHalf()
+ + A1B1.GetLowHalf();
+ C[1] = t.GetLowHalf();
+
+ t = A1B1 + t.GetHighHalf() + A0B0.GetHighHalf() + d.GetHighHalf()
+ + A1B1.GetHighHalf() - s;
+ C[2] = t.GetLowHalf();
+ C[3] = t.GetHighHalf();
+}
+
+void Portable::Multiply2Bottom(word *C, const word *A, const word *B)
+{
+ DWord t = DWord::Multiply(A[0], B[0]);
+ C[0] = t.GetLowHalf();
+ C[1] = t.GetHighHalf() + A[0]*B[1] + A[1]*B[0];
+}
+
+word Portable::Multiply2Add(word *C, const word *A, const word *B)
+{
+ word D[4] = {A[1]-A[0], A[0]-A[1], B[0]-B[1], B[1]-B[0]};
+ unsigned int ai = A[1] < A[0];
+ unsigned int bi = B[0] < B[1];
+ unsigned int di = ai & bi;
+ DWord d = DWord::Multiply(D[di], D[di+2]);
+ D[1] = D[3] = 0;
+ unsigned int si = ai + !bi;
+ word s = D[si];
+
+ DWord A0B0 = DWord::Multiply(A[0], B[0]);
+ DWord t = A0B0 + C[0];
+ C[0] = t.GetLowHalf();
+
+ DWord A1B1 = DWord::Multiply(A[1], B[1]);
+ t = (DWord) t.GetHighHalf() + A0B0.GetLowHalf() + d.GetLowHalf() +
+ A1B1.GetLowHalf() + C[1];
+ C[1] = t.GetLowHalf();
+
+ t = (DWord) t.GetHighHalf() + A1B1.GetLowHalf() + A0B0.GetHighHalf() +
+ d.GetHighHalf() + A1B1.GetHighHalf() - s + C[2];
+ C[2] = t.GetLowHalf();
+
+ t = (DWord) t.GetHighHalf() + A1B1.GetHighHalf() + C[3];
+ C[3] = t.GetLowHalf();
+ return t.GetHighHalf();
+}
+
+
+#define MulAcc(x, y) \
+ p = DWord::MultiplyAndAdd(A[x], B[y], c); \
+ c = p.GetLowHalf(); \
+ p = (DWord) d + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e += p.GetHighHalf();
+
+#define SaveMulAcc(s, x, y) \
+ R[s] = c; \
+ p = DWord::MultiplyAndAdd(A[x], B[y], d); \
+ c = p.GetLowHalf(); \
+ p = (DWord) e + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e = p.GetHighHalf();
+
+#define SquAcc(x, y) \
+ q = DWord::Multiply(A[x], A[y]); \
+ p = q + c; \
+ c = p.GetLowHalf(); \
+ p = (DWord) d + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e += p.GetHighHalf(); \
+ p = q + c; \
+ c = p.GetLowHalf(); \
+ p = (DWord) d + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e += p.GetHighHalf();
+
+#define SaveSquAcc(s, x, y) \
+ R[s] = c; \
+ q = DWord::Multiply(A[x], A[y]); \
+ p = q + d; \
+ c = p.GetLowHalf(); \
+ p = (DWord) e + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e = p.GetHighHalf(); \
+ p = q + c; \
+ c = p.GetLowHalf(); \
+ p = (DWord) d + p.GetHighHalf(); \
+ d = p.GetLowHalf(); \
+ e += p.GetHighHalf();
+
+
+void Portable::Multiply4(word *R, const word *A, const word *B)
+{
+ DWord p;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], B[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ MulAcc(0, 1);
+ MulAcc(1, 0);
+
+ SaveMulAcc(1, 2, 0);
+ MulAcc(1, 1);
+ MulAcc(0, 2);
+
+ SaveMulAcc(2, 0, 3);
+ MulAcc(1, 2);
+ MulAcc(2, 1);
+ MulAcc(3, 0);
+
+ SaveMulAcc(3, 3, 1);
+ MulAcc(2, 2);
+ MulAcc(1, 3);
+
+ SaveMulAcc(4, 2, 3);
+ MulAcc(3, 2);
+
+ R[5] = c;
+ p = DWord::MultiplyAndAdd(A[3], B[3], d);
+ R[6] = p.GetLowHalf();
+ R[7] = e + p.GetHighHalf();
+}
+
+void Portable::Square2(word *R, const word *A)
+{
+ DWord p, q;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], A[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ SquAcc(0, 1);
+
+ R[1] = c;
+ p = DWord::MultiplyAndAdd(A[1], A[1], d);
+ R[2] = p.GetLowHalf();
+ R[3] = e + p.GetHighHalf();
+}
+
+void Portable::Square4(word *R, const word *A)
+{
+#ifdef _MSC_VER
+ // VC60 workaround: MSVC 6.0 has an optimization bug that makes
+ // (dword)A*B where either A or B has been cast to a dword before
+ // very expensive. Revisit this function when this
+ // bug is fixed.
+ Multiply4(R, A, A);
+#else
+ const word *B = A;
+ DWord p, q;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], A[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ SquAcc(0, 1);
+
+ SaveSquAcc(1, 2, 0);
+ MulAcc(1, 1);
+
+ SaveSquAcc(2, 0, 3);
+ SquAcc(1, 2);
+
+ SaveSquAcc(3, 3, 1);
+ MulAcc(2, 2);
+
+ SaveSquAcc(4, 2, 3);
+
+ R[5] = c;
+ p = DWord::MultiplyAndAdd(A[3], A[3], d);
+ R[6] = p.GetLowHalf();
+ R[7] = e + p.GetHighHalf();
+#endif
+}
+
+void Portable::Multiply8(word *R, const word *A, const word *B)
+{
+ DWord p;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], B[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ MulAcc(0, 1);
+ MulAcc(1, 0);
+
+ SaveMulAcc(1, 2, 0);
+ MulAcc(1, 1);
+ MulAcc(0, 2);
+
+ SaveMulAcc(2, 0, 3);
+ MulAcc(1, 2);
+ MulAcc(2, 1);
+ MulAcc(3, 0);
+
+ SaveMulAcc(3, 0, 4);
+ MulAcc(1, 3);
+ MulAcc(2, 2);
+ MulAcc(3, 1);
+ MulAcc(4, 0);
+
+ SaveMulAcc(4, 0, 5);
+ MulAcc(1, 4);
+ MulAcc(2, 3);
+ MulAcc(3, 2);
+ MulAcc(4, 1);
+ MulAcc(5, 0);
+
+ SaveMulAcc(5, 0, 6);
+ MulAcc(1, 5);
+ MulAcc(2, 4);
+ MulAcc(3, 3);
+ MulAcc(4, 2);
+ MulAcc(5, 1);
+ MulAcc(6, 0);
+
+ SaveMulAcc(6, 0, 7);
+ MulAcc(1, 6);
+ MulAcc(2, 5);
+ MulAcc(3, 4);
+ MulAcc(4, 3);
+ MulAcc(5, 2);
+ MulAcc(6, 1);
+ MulAcc(7, 0);
+
+ SaveMulAcc(7, 1, 7);
+ MulAcc(2, 6);
+ MulAcc(3, 5);
+ MulAcc(4, 4);
+ MulAcc(5, 3);
+ MulAcc(6, 2);
+ MulAcc(7, 1);
+
+ SaveMulAcc(8, 2, 7);
+ MulAcc(3, 6);
+ MulAcc(4, 5);
+ MulAcc(5, 4);
+ MulAcc(6, 3);
+ MulAcc(7, 2);
+
+ SaveMulAcc(9, 3, 7);
+ MulAcc(4, 6);
+ MulAcc(5, 5);
+ MulAcc(6, 4);
+ MulAcc(7, 3);
+
+ SaveMulAcc(10, 4, 7);
+ MulAcc(5, 6);
+ MulAcc(6, 5);
+ MulAcc(7, 4);
+
+ SaveMulAcc(11, 5, 7);
+ MulAcc(6, 6);
+ MulAcc(7, 5);
+
+ SaveMulAcc(12, 6, 7);
+ MulAcc(7, 6);
+
+ R[13] = c;
+ p = DWord::MultiplyAndAdd(A[7], B[7], d);
+ R[14] = p.GetLowHalf();
+ R[15] = e + p.GetHighHalf();
+}
+
+void Portable::Multiply4Bottom(word *R, const word *A, const word *B)
+{
+ DWord p;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], B[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ MulAcc(0, 1);
+ MulAcc(1, 0);
+
+ SaveMulAcc(1, 2, 0);
+ MulAcc(1, 1);
+ MulAcc(0, 2);
+
+ R[2] = c;
+ R[3] = d + A[0] * B[3] + A[1] * B[2] + A[2] * B[1] + A[3] * B[0];
+}
+
+void Portable::Multiply8Bottom(word *R, const word *A, const word *B)
+{
+ DWord p;
+ word c, d, e;
+
+ p = DWord::Multiply(A[0], B[0]);
+ R[0] = p.GetLowHalf();
+ c = p.GetHighHalf();
+ d = e = 0;
+
+ MulAcc(0, 1);
+ MulAcc(1, 0);
+
+ SaveMulAcc(1, 2, 0);
+ MulAcc(1, 1);
+ MulAcc(0, 2);
+
+ SaveMulAcc(2, 0, 3);
+ MulAcc(1, 2);
+ MulAcc(2, 1);
+ MulAcc(3, 0);
+
+ SaveMulAcc(3, 0, 4);
+ MulAcc(1, 3);
+ MulAcc(2, 2);
+ MulAcc(3, 1);
+ MulAcc(4, 0);
+
+ SaveMulAcc(4, 0, 5);
+ MulAcc(1, 4);
+ MulAcc(2, 3);
+ MulAcc(3, 2);
+ MulAcc(4, 1);
+ MulAcc(5, 0);
+
+ SaveMulAcc(5, 0, 6);
+ MulAcc(1, 5);
+ MulAcc(2, 4);
+ MulAcc(3, 3);
+ MulAcc(4, 2);
+ MulAcc(5, 1);
+ MulAcc(6, 0);
+
+ R[6] = c;
+ R[7] = d + A[0] * B[7] + A[1] * B[6] + A[2] * B[5] + A[3] * B[4] +
+ A[4] * B[3] + A[5] * B[2] + A[6] * B[1] + A[7] * B[0];
+}
+
+
+#undef MulAcc
+#undef SaveMulAcc
+#undef SquAcc
+#undef SaveSquAcc
+
+// optimized
+
+#ifdef TAOCRYPT_X86ASM_AVAILABLE
+
+// ************** x86 feature detection ***************
+
+
+#ifdef SSE2_INTRINSICS_AVAILABLE
+
+#ifndef _MSC_VER
+ static jmp_buf s_env;
+ static void SigIllHandler(int)
+ {
+ longjmp(s_env, 1);
+ }
+#endif
+
+static bool HasSSE2()
+{
+ if (!IsPentium())
+ return false;
+
+ word32 cpuid[4];
+ CpuId(1, cpuid);
+ if ((cpuid[3] & (1 << 26)) == 0)
+ return false;
+
+#ifdef _MSC_VER
+ __try
+ {
+ __asm xorpd xmm0, xmm0 // executing SSE2 instruction
+ }
+ __except (1)
+ {
+ return false;
+ }
+ return true;
+#else
+ typedef void (*SigHandler)(int);
+
+ SigHandler oldHandler = signal(SIGILL, SigIllHandler);
+ if (oldHandler == SIG_ERR)
+ return false;
+
+ bool result = true;
+ if (setjmp(s_env))
+ result = false;
+ else
+ __asm __volatile ("xorpd %xmm0, %xmm0");
+
+ signal(SIGILL, oldHandler);
+ return result;
+#endif
+}
+#endif // SSE2_INTRINSICS_AVAILABLE
+
+
+static bool IsP4()
+{
+ if (!IsPentium())
+ return false;
+
+ word32 cpuid[4];
+
+ CpuId(1, cpuid);
+ return ((cpuid[0] >> 8) & 0xf) == 0xf;
+}
+
+// ************** Pentium/P4 optimizations ***************
+
+class PentiumOptimized : public Portable
+{
+public:
+ static word TAOCRYPT_CDECL Add(word *C, const word *A, const word *B,
+ unsigned int N);
+ static word TAOCRYPT_CDECL Subtract(word *C, const word *A, const word *B,
+ unsigned int N);
+ static void TAOCRYPT_CDECL Multiply4(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply8(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply8Bottom(word *C, const word *A,
+ const word *B);
+};
+
+class P4Optimized
+{
+public:
+ static word TAOCRYPT_CDECL Add(word *C, const word *A, const word *B,
+ unsigned int N);
+ static word TAOCRYPT_CDECL Subtract(word *C, const word *A, const word *B,
+ unsigned int N);
+#ifdef SSE2_INTRINSICS_AVAILABLE
+ static void TAOCRYPT_CDECL Multiply4(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply8(word *C, const word *A,
+ const word *B);
+ static void TAOCRYPT_CDECL Multiply8Bottom(word *C, const word *A,
+ const word *B);
+#endif
+};
+
+typedef word (TAOCRYPT_CDECL * PAddSub)(word *C, const word *A, const word *B,
+ unsigned int N);
+typedef void (TAOCRYPT_CDECL * PMul)(word *C, const word *A, const word *B);
+
+static PAddSub s_pAdd, s_pSub;
+#ifdef SSE2_INTRINSICS_AVAILABLE
+static PMul s_pMul4, s_pMul8, s_pMul8B;
+#endif
+
+static void SetPentiumFunctionPointers()
+{
+ if (!IsPentium())
+ {
+ s_pAdd = &Portable::Add;
+ s_pSub = &Portable::Subtract;
+ }
+ else if (IsP4())
+ {
+ s_pAdd = &P4Optimized::Add;
+ s_pSub = &P4Optimized::Subtract;
+ }
+ else
+ {
+ s_pAdd = &PentiumOptimized::Add;
+ s_pSub = &PentiumOptimized::Subtract;
+ }
+
+#ifdef SSE2_INTRINSICS_AVAILABLE
+ if (!IsPentium())
+ {
+ s_pMul4 = &Portable::Multiply4;
+ s_pMul8 = &Portable::Multiply8;
+ s_pMul8B = &Portable::Multiply8Bottom;
+ }
+ else if (HasSSE2())
+ {
+ s_pMul4 = &P4Optimized::Multiply4;
+ s_pMul8 = &P4Optimized::Multiply8;
+ s_pMul8B = &P4Optimized::Multiply8Bottom;
+ }
+ else
+ {
+ s_pMul4 = &PentiumOptimized::Multiply4;
+ s_pMul8 = &PentiumOptimized::Multiply8;
+ s_pMul8B = &PentiumOptimized::Multiply8Bottom;
+ }
+#endif
+}
+
+static const char s_RunAtStartupSetPentiumFunctionPointers =
+ (SetPentiumFunctionPointers(), 0);
+
+
+class LowLevel : public PentiumOptimized
+{
+public:
+ inline static word Add(word *C, const word *A, const word *B,
+ unsigned int N)
+ {return s_pAdd(C, A, B, N);}
+ inline static word Subtract(word *C, const word *A, const word *B,
+ unsigned int N)
+ {return s_pSub(C, A, B, N);}
+ inline static void Square4(word *R, const word *A)
+ {Multiply4(R, A, A);}
+#ifdef SSE2_INTRINSICS_AVAILABLE
+ inline static void Multiply4(word *C, const word *A, const word *B)
+ {s_pMul4(C, A, B);}
+ inline static void Multiply8(word *C, const word *A, const word *B)
+ {s_pMul8(C, A, B);}
+ inline static void Multiply8Bottom(word *C, const word *A, const word *B)
+ {s_pMul8B(C, A, B);}
+#endif
+};
+
+// use some tricks to share assembly code between MSVC and GCC
+#ifdef _MSC_VER
+ #define TAOCRYPT_NAKED __declspec(naked)
+ #define AS1(x) __asm x
+ #define AS2(x, y) __asm x, y
+ #define AddPrologue \
+ __asm push ebp \
+ __asm push ebx \
+ __asm push esi \
+ __asm push edi \
+ __asm mov ecx, [esp+20] \
+ __asm mov edx, [esp+24] \
+ __asm mov ebx, [esp+28] \
+ __asm mov esi, [esp+32]
+ #define AddEpilogue \
+ __asm pop edi \
+ __asm pop esi \
+ __asm pop ebx \
+ __asm pop ebp \
+ __asm ret
+ #define MulPrologue \
+ __asm push ebp \
+ __asm push ebx \
+ __asm push esi \
+ __asm push edi \
+ __asm mov ecx, [esp+28] \
+ __asm mov esi, [esp+24] \
+ __asm push [esp+20]
+ #define MulEpilogue \
+ __asm add esp, 4 \
+ __asm pop edi \
+ __asm pop esi \
+ __asm pop ebx \
+ __asm pop ebp \
+ __asm ret
+#else
+ #define TAOCRYPT_NAKED
+ #define AS1(x) #x ";"
+ #define AS2(x, y) #x ", " #y ";"
+ #define AddPrologue \
+ word res; \
+ __asm__ __volatile__ \
+ ( \
+ "push %%ebx;" /* save this manually, in case of -fPIC */ \
+ "mov %3, %%ebx;" \
+ ".intel_syntax noprefix;" \
+ "push ebp;"
+ #define AddEpilogue \
+ "pop ebp;" \
+ ".att_syntax prefix;" \
+ "pop %%ebx;" \
+ "mov %%eax, %0;" \
+ : "=g" (res) \
+ : "c" (C), "d" (A), "m" (B), "S" (N) \
+ : "%edi", "memory", "cc" \
+ ); \
+ return res;
+
+ #define MulPrologue \
+ __asm__ __volatile__ \
+ ( \
+ "push %%ebx;" /* save this manually, in case of -fPIC */ \
+ "push %%ebp;" \
+ "push %0;" \
+ ".intel_syntax noprefix;"
+ #define MulEpilogue \
+ "add esp, 4;" \
+ "pop ebp;" \
+ "pop ebx;" \
+ ".att_syntax prefix;" \
+ : \
+ : "rm" (Z), "S" (X), "c" (Y) \
+ : "%eax", "%edx", "%edi", "memory", "cc" \
+ );
+#endif
+
+TAOCRYPT_NAKED word PentiumOptimized::Add(word *C, const word *A,
+ const word *B, unsigned int N)
+{
+ AddPrologue
+
+ // now: ebx = B, ecx = C, edx = A, esi = N
+ AS2( sub ecx, edx) // hold the distance between C & A so we
+ // can add this to A to get C
+ AS2( xor eax, eax) // clear eax
+
+ AS2( sub eax, esi) // eax is a negative index from end of B
+ AS2( lea ebx, [ebx+4*esi]) // ebx is end of B
+
+ AS2( sar eax, 1) // unit of eax is now dwords; this also
+ // clears the carry flag
+ AS1( jz loopendAdd) // if no dwords then nothing to do
+
+ AS1(loopstartAdd:)
+ AS2( mov esi,[edx]) // load lower word of A
+ AS2( mov ebp,[edx+4]) // load higher word of A
+
+ AS2( mov edi,[ebx+8*eax]) // load lower word of B
+ AS2( lea edx,[edx+8]) // advance A and C
+
+ AS2( adc esi,edi) // add lower words
+ AS2( mov edi,[ebx+8*eax+4]) // load higher word of B
+
+ AS2( adc ebp,edi) // add higher words
+ AS1( inc eax) // advance B
+
+ AS2( mov [edx+ecx-8],esi) // store lower word result
+ AS2( mov [edx+ecx-4],ebp) // store higher word result
+
+ AS1( jnz loopstartAdd) // loop until eax overflows and becomes zero
+
+ AS1(loopendAdd:)
+ AS2( adc eax, 0) // store carry into eax (return result register)
+
+ AddEpilogue
+}
+
+TAOCRYPT_NAKED word PentiumOptimized::Subtract(word *C, const word *A,
+ const word *B, unsigned int N)
+{
+ AddPrologue
+
+ // now: ebx = B, ecx = C, edx = A, esi = N
+ AS2( sub ecx, edx) // hold the distance between C & A so we
+ // can add this to A to get C
+ AS2( xor eax, eax) // clear eax
+
+ AS2( sub eax, esi) // eax is a negative index from end of B
+ AS2( lea ebx, [ebx+4*esi]) // ebx is end of B
+
+ AS2( sar eax, 1) // unit of eax is now dwords; this also
+ // clears the carry flag
+ AS1( jz loopendSub) // if no dwords then nothing to do
+
+ AS1(loopstartSub:)
+ AS2( mov esi,[edx]) // load lower word of A
+ AS2( mov ebp,[edx+4]) // load higher word of A
+
+ AS2( mov edi,[ebx+8*eax]) // load lower word of B
+ AS2( lea edx,[edx+8]) // advance A and C
+
+ AS2( sbb esi,edi) // subtract lower words
+ AS2( mov edi,[ebx+8*eax+4]) // load higher word of B
+
+ AS2( sbb ebp,edi) // subtract higher words
+ AS1( inc eax) // advance B
+
+ AS2( mov [edx+ecx-8],esi) // store lower word result
+ AS2( mov [edx+ecx-4],ebp) // store higher word result
+
+ AS1( jnz loopstartSub) // loop until eax overflows and becomes zero
+
+ AS1(loopendSub:)
+ AS2( adc eax, 0) // store carry into eax (return result register)
+
+ AddEpilogue
+}
+
+// On Pentium 4, the adc and sbb instructions are very expensive, so avoid them.
+
+TAOCRYPT_NAKED word P4Optimized::Add(word *C, const word *A, const word *B,
+ unsigned int N)
+{
+ AddPrologue
+
+ // now: ebx = B, ecx = C, edx = A, esi = N
+ AS2( xor eax, eax)
+ AS1( neg esi)
+ AS1( jz loopendAddP4) // if no dwords then nothing to do
+
+ AS2( mov edi, [edx])
+ AS2( mov ebp, [ebx])
+ AS1( jmp carry1AddP4)
+
+ AS1(loopstartAddP4:)
+ AS2( mov edi, [edx+8])
+ AS2( add ecx, 8)
+ AS2( add edx, 8)
+ AS2( mov ebp, [ebx])
+ AS2( add edi, eax)
+ AS1( jc carry1AddP4)
+ AS2( xor eax, eax)
+
+ AS1(carry1AddP4:)
+ AS2( add edi, ebp)
+ AS2( mov ebp, 1)
+ AS2( mov [ecx], edi)
+ AS2( mov edi, [edx+4])
+ AS2( cmovc eax, ebp)
+ AS2( mov ebp, [ebx+4])
+ AS2( add ebx, 8)
+ AS2( add edi, eax)
+ AS1( jc carry2AddP4)
+ AS2( xor eax, eax)
+
+ AS1(carry2AddP4:)
+ AS2( add edi, ebp)
+ AS2( mov ebp, 1)
+ AS2( cmovc eax, ebp)
+ AS2( mov [ecx+4], edi)
+ AS2( add esi, 2)
+ AS1( jnz loopstartAddP4)
+
+ AS1(loopendAddP4:)
+
+ AddEpilogue
+}
+
+TAOCRYPT_NAKED word P4Optimized::Subtract(word *C, const word *A,
+ const word *B, unsigned int N)
+{
+ AddPrologue
+
+ // now: ebx = B, ecx = C, edx = A, esi = N
+ AS2( xor eax, eax)
+ AS1( neg esi)
+ AS1( jz loopendSubP4) // if no dwords then nothing to do
+
+ AS2( mov edi, [edx])
+ AS2( mov ebp, [ebx])
+ AS1( jmp carry1SubP4)
+
+ AS1(loopstartSubP4:)
+ AS2( mov edi, [edx+8])
+ AS2( add edx, 8)
+ AS2( add ecx, 8)
+ AS2( mov ebp, [ebx])
+ AS2( sub edi, eax)
+ AS1( jc carry1SubP4)
+ AS2( xor eax, eax)
+
+ AS1(carry1SubP4:)
+ AS2( sub edi, ebp)
+ AS2( mov ebp, 1)
+ AS2( mov [ecx], edi)
+ AS2( mov edi, [edx+4])
+ AS2( cmovc eax, ebp)
+ AS2( mov ebp, [ebx+4])
+ AS2( add ebx, 8)
+ AS2( sub edi, eax)
+ AS1( jc carry2SubP4)
+ AS2( xor eax, eax)
+
+ AS1(carry2SubP4:)
+ AS2( sub edi, ebp)
+ AS2( mov ebp, 1)
+ AS2( cmovc eax, ebp)
+ AS2( mov [ecx+4], edi)
+ AS2( add esi, 2)
+ AS1( jnz loopstartSubP4)
+
+ AS1(loopendSubP4:)
+
+ AddEpilogue
+}
+
+// multiply assembly code originally contributed by Leonard Janke
+
+#define MulStartup \
+ AS2(xor ebp, ebp) \
+ AS2(xor edi, edi) \
+ AS2(xor ebx, ebx)
+
+#define MulShiftCarry \
+ AS2(mov ebp, edx) \
+ AS2(mov edi, ebx) \
+ AS2(xor ebx, ebx)
+
+#define MulAccumulateBottom(i,j) \
+ AS2(mov eax, [ecx+4*j]) \
+ AS2(imul eax, dword ptr [esi+4*i]) \
+ AS2(add ebp, eax)
+
+#define MulAccumulate(i,j) \
+ AS2(mov eax, [ecx+4*j]) \
+ AS1(mul dword ptr [esi+4*i]) \
+ AS2(add ebp, eax) \
+ AS2(adc edi, edx) \
+ AS2(adc bl, bh)
+
+#define MulStoreDigit(i) \
+ AS2(mov edx, edi) \
+ AS2(mov edi, [esp]) \
+ AS2(mov [edi+4*i], ebp)
+
+#define MulLastDiagonal(digits) \
+ AS2(mov eax, [ecx+4*(digits-1)]) \
+ AS1(mul dword ptr [esi+4*(digits-1)]) \
+ AS2(add ebp, eax) \
+ AS2(adc edx, edi) \
+ AS2(mov edi, [esp]) \
+ AS2(mov [edi+4*(2*digits-2)], ebp) \
+ AS2(mov [edi+4*(2*digits-1)], edx)
+
+TAOCRYPT_NAKED void PentiumOptimized::Multiply4(word* Z, const word* X,
+ const word* Y)
+{
+ MulPrologue
+ // now: [esp] = Z, esi = X, ecx = Y
+ MulStartup
+ MulAccumulate(0,0)
+ MulStoreDigit(0)
+ MulShiftCarry
+
+ MulAccumulate(1,0)
+ MulAccumulate(0,1)
+ MulStoreDigit(1)
+ MulShiftCarry
+
+ MulAccumulate(2,0)
+ MulAccumulate(1,1)
+ MulAccumulate(0,2)
+ MulStoreDigit(2)
+ MulShiftCarry
+
+ MulAccumulate(3,0)
+ MulAccumulate(2,1)
+ MulAccumulate(1,2)
+ MulAccumulate(0,3)
+ MulStoreDigit(3)
+ MulShiftCarry
+
+ MulAccumulate(3,1)
+ MulAccumulate(2,2)
+ MulAccumulate(1,3)
+ MulStoreDigit(4)
+ MulShiftCarry
+
+ MulAccumulate(3,2)
+ MulAccumulate(2,3)
+ MulStoreDigit(5)
+ MulShiftCarry
+
+ MulLastDiagonal(4)
+ MulEpilogue
+}
+
+TAOCRYPT_NAKED void PentiumOptimized::Multiply8(word* Z, const word* X,
+ const word* Y)
+{
+ MulPrologue
+ // now: [esp] = Z, esi = X, ecx = Y
+ MulStartup
+ MulAccumulate(0,0)
+ MulStoreDigit(0)
+ MulShiftCarry
+
+ MulAccumulate(1,0)
+ MulAccumulate(0,1)
+ MulStoreDigit(1)
+ MulShiftCarry
+
+ MulAccumulate(2,0)
+ MulAccumulate(1,1)
+ MulAccumulate(0,2)
+ MulStoreDigit(2)
+ MulShiftCarry
+
+ MulAccumulate(3,0)
+ MulAccumulate(2,1)
+ MulAccumulate(1,2)
+ MulAccumulate(0,3)
+ MulStoreDigit(3)
+ MulShiftCarry
+
+ MulAccumulate(4,0)
+ MulAccumulate(3,1)
+ MulAccumulate(2,2)
+ MulAccumulate(1,3)
+ MulAccumulate(0,4)
+ MulStoreDigit(4)
+ MulShiftCarry
+
+ MulAccumulate(5,0)
+ MulAccumulate(4,1)
+ MulAccumulate(3,2)
+ MulAccumulate(2,3)
+ MulAccumulate(1,4)
+ MulAccumulate(0,5)
+ MulStoreDigit(5)
+ MulShiftCarry
+
+ MulAccumulate(6,0)
+ MulAccumulate(5,1)
+ MulAccumulate(4,2)
+ MulAccumulate(3,3)
+ MulAccumulate(2,4)
+ MulAccumulate(1,5)
+ MulAccumulate(0,6)
+ MulStoreDigit(6)
+ MulShiftCarry
+
+ MulAccumulate(7,0)
+ MulAccumulate(6,1)
+ MulAccumulate(5,2)
+ MulAccumulate(4,3)
+ MulAccumulate(3,4)
+ MulAccumulate(2,5)
+ MulAccumulate(1,6)
+ MulAccumulate(0,7)
+ MulStoreDigit(7)
+ MulShiftCarry
+
+ MulAccumulate(7,1)
+ MulAccumulate(6,2)
+ MulAccumulate(5,3)
+ MulAccumulate(4,4)
+ MulAccumulate(3,5)
+ MulAccumulate(2,6)
+ MulAccumulate(1,7)
+ MulStoreDigit(8)
+ MulShiftCarry
+
+ MulAccumulate(7,2)
+ MulAccumulate(6,3)
+ MulAccumulate(5,4)
+ MulAccumulate(4,5)
+ MulAccumulate(3,6)
+ MulAccumulate(2,7)
+ MulStoreDigit(9)
+ MulShiftCarry
+
+ MulAccumulate(7,3)
+ MulAccumulate(6,4)
+ MulAccumulate(5,5)
+ MulAccumulate(4,6)
+ MulAccumulate(3,7)
+ MulStoreDigit(10)
+ MulShiftCarry
+
+ MulAccumulate(7,4)
+ MulAccumulate(6,5)
+ MulAccumulate(5,6)
+ MulAccumulate(4,7)
+ MulStoreDigit(11)
+ MulShiftCarry
+
+ MulAccumulate(7,5)
+ MulAccumulate(6,6)
+ MulAccumulate(5,7)
+ MulStoreDigit(12)
+ MulShiftCarry
+
+ MulAccumulate(7,6)
+ MulAccumulate(6,7)
+ MulStoreDigit(13)
+ MulShiftCarry
+
+ MulLastDiagonal(8)
+ MulEpilogue
+}
+
+TAOCRYPT_NAKED void PentiumOptimized::Multiply8Bottom(word* Z, const word* X,
+ const word* Y)
+{
+ MulPrologue
+ // now: [esp] = Z, esi = X, ecx = Y
+ MulStartup
+ MulAccumulate(0,0)
+ MulStoreDigit(0)
+ MulShiftCarry
+
+ MulAccumulate(1,0)
+ MulAccumulate(0,1)
+ MulStoreDigit(1)
+ MulShiftCarry
+
+ MulAccumulate(2,0)
+ MulAccumulate(1,1)
+ MulAccumulate(0,2)
+ MulStoreDigit(2)
+ MulShiftCarry
+
+ MulAccumulate(3,0)
+ MulAccumulate(2,1)
+ MulAccumulate(1,2)
+ MulAccumulate(0,3)
+ MulStoreDigit(3)
+ MulShiftCarry
+
+ MulAccumulate(4,0)
+ MulAccumulate(3,1)
+ MulAccumulate(2,2)
+ MulAccumulate(1,3)
+ MulAccumulate(0,4)
+ MulStoreDigit(4)
+ MulShiftCarry
+
+ MulAccumulate(5,0)
+ MulAccumulate(4,1)
+ MulAccumulate(3,2)
+ MulAccumulate(2,3)
+ MulAccumulate(1,4)
+ MulAccumulate(0,5)
+ MulStoreDigit(5)
+ MulShiftCarry
+
+ MulAccumulate(6,0)
+ MulAccumulate(5,1)
+ MulAccumulate(4,2)
+ MulAccumulate(3,3)
+ MulAccumulate(2,4)
+ MulAccumulate(1,5)
+ MulAccumulate(0,6)
+ MulStoreDigit(6)
+ MulShiftCarry
+
+ MulAccumulateBottom(7,0)
+ MulAccumulateBottom(6,1)
+ MulAccumulateBottom(5,2)
+ MulAccumulateBottom(4,3)
+ MulAccumulateBottom(3,4)
+ MulAccumulateBottom(2,5)
+ MulAccumulateBottom(1,6)
+ MulAccumulateBottom(0,7)
+ MulStoreDigit(7)
+ MulEpilogue
+}
+
+#undef AS1
+#undef AS2
+
+#else // not x86 - no processor specific code at this layer
+
+typedef Portable LowLevel;
+
+#endif
+
+#ifdef SSE2_INTRINSICS_AVAILABLE
+
+#ifdef __GNUC__
+#define TAOCRYPT_FASTCALL
+#else
+#define TAOCRYPT_FASTCALL __fastcall
+#endif
+
+static void TAOCRYPT_FASTCALL P4_Mul(__m128i *C, const __m128i *A,
+ const __m128i *B)
+{
+ __m128i a3210 = _mm_load_si128(A);
+ __m128i b3210 = _mm_load_si128(B);
+
+ __m128i sum;
+
+ __m128i z = _mm_setzero_si128();
+ __m128i a2b2_a0b0 = _mm_mul_epu32(a3210, b3210);
+ C[0] = a2b2_a0b0;
+
+ __m128i a3120 = _mm_shuffle_epi32(a3210, _MM_SHUFFLE(3, 1, 2, 0));
+ __m128i b3021 = _mm_shuffle_epi32(b3210, _MM_SHUFFLE(3, 0, 2, 1));
+ __m128i a1b0_a0b1 = _mm_mul_epu32(a3120, b3021);
+ __m128i a1b0 = _mm_unpackhi_epi32(a1b0_a0b1, z);
+ __m128i a0b1 = _mm_unpacklo_epi32(a1b0_a0b1, z);
+ C[1] = _mm_add_epi64(a1b0, a0b1);
+
+ __m128i a31 = _mm_srli_epi64(a3210, 32);
+ __m128i b31 = _mm_srli_epi64(b3210, 32);
+ __m128i a3b3_a1b1 = _mm_mul_epu32(a31, b31);
+ C[6] = a3b3_a1b1;
+
+ __m128i a1b1 = _mm_unpacklo_epi32(a3b3_a1b1, z);
+ __m128i b3012 = _mm_shuffle_epi32(b3210, _MM_SHUFFLE(3, 0, 1, 2));
+ __m128i a2b0_a0b2 = _mm_mul_epu32(a3210, b3012);
+ __m128i a0b2 = _mm_unpacklo_epi32(a2b0_a0b2, z);
+ __m128i a2b0 = _mm_unpackhi_epi32(a2b0_a0b2, z);
+ sum = _mm_add_epi64(a1b1, a0b2);
+ C[2] = _mm_add_epi64(sum, a2b0);
+
+ __m128i a2301 = _mm_shuffle_epi32(a3210, _MM_SHUFFLE(2, 3, 0, 1));
+ __m128i b2103 = _mm_shuffle_epi32(b3210, _MM_SHUFFLE(2, 1, 0, 3));
+ __m128i a3b0_a1b2 = _mm_mul_epu32(a2301, b3012);
+ __m128i a2b1_a0b3 = _mm_mul_epu32(a3210, b2103);
+ __m128i a3b0 = _mm_unpackhi_epi32(a3b0_a1b2, z);
+ __m128i a1b2 = _mm_unpacklo_epi32(a3b0_a1b2, z);
+ __m128i a2b1 = _mm_unpackhi_epi32(a2b1_a0b3, z);
+ __m128i a0b3 = _mm_unpacklo_epi32(a2b1_a0b3, z);
+ __m128i sum1 = _mm_add_epi64(a3b0, a1b2);
+ sum = _mm_add_epi64(a2b1, a0b3);
+ C[3] = _mm_add_epi64(sum, sum1);
+
+ __m128i a3b1_a1b3 = _mm_mul_epu32(a2301, b2103);
+ __m128i a2b2 = _mm_unpackhi_epi32(a2b2_a0b0, z);
+ __m128i a3b1 = _mm_unpackhi_epi32(a3b1_a1b3, z);
+ __m128i a1b3 = _mm_unpacklo_epi32(a3b1_a1b3, z);
+ sum = _mm_add_epi64(a2b2, a3b1);
+ C[4] = _mm_add_epi64(sum, a1b3);
+
+ __m128i a1302 = _mm_shuffle_epi32(a3210, _MM_SHUFFLE(1, 3, 0, 2));
+ __m128i b1203 = _mm_shuffle_epi32(b3210, _MM_SHUFFLE(1, 2, 0, 3));
+ __m128i a3b2_a2b3 = _mm_mul_epu32(a1302, b1203);
+ __m128i a3b2 = _mm_unpackhi_epi32(a3b2_a2b3, z);
+ __m128i a2b3 = _mm_unpacklo_epi32(a3b2_a2b3, z);
+ C[5] = _mm_add_epi64(a3b2, a2b3);
+}
+
+void P4Optimized::Multiply4(word *C, const word *A, const word *B)
+{
+ __m128i temp[7];
+ const word *w = (word *)temp;
+ const __m64 *mw = (__m64 *)w;
+
+ P4_Mul(temp, (__m128i *)A, (__m128i *)B);
+
+ C[0] = w[0];
+
+ __m64 s1, s2;
+
+ __m64 w1 = _mm_cvtsi32_si64(w[1]);
+ __m64 w4 = mw[2];
+ __m64 w6 = mw[3];
+ __m64 w8 = mw[4];
+ __m64 w10 = mw[5];
+ __m64 w12 = mw[6];
+ __m64 w14 = mw[7];
+ __m64 w16 = mw[8];
+ __m64 w18 = mw[9];
+ __m64 w20 = mw[10];
+ __m64 w22 = mw[11];
+ __m64 w26 = _mm_cvtsi32_si64(w[26]);
+
+ s1 = _mm_add_si64(w1, w4);
+ C[1] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w6, w8);
+ s1 = _mm_add_si64(s1, s2);
+ C[2] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w10, w12);
+ s1 = _mm_add_si64(s1, s2);
+ C[3] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w14, w16);
+ s1 = _mm_add_si64(s1, s2);
+ C[4] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w18, w20);
+ s1 = _mm_add_si64(s1, s2);
+ C[5] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w22, w26);
+ s1 = _mm_add_si64(s1, s2);
+ C[6] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ C[7] = _mm_cvtsi64_si32(s1) + w[27];
+ _mm_empty();
+}
+
+void P4Optimized::Multiply8(word *C, const word *A, const word *B)
+{
+ __m128i temp[28];
+ const word *w = (word *)temp;
+ const __m64 *mw = (__m64 *)w;
+ const word *x = (word *)temp+7*4;
+ const __m64 *mx = (__m64 *)x;
+ const word *y = (word *)temp+7*4*2;
+ const __m64 *my = (__m64 *)y;
+ const word *z = (word *)temp+7*4*3;
+ const __m64 *mz = (__m64 *)z;
+
+ P4_Mul(temp, (__m128i *)A, (__m128i *)B);
+
+ P4_Mul(temp+7, (__m128i *)A+1, (__m128i *)B);
+
+ P4_Mul(temp+14, (__m128i *)A, (__m128i *)B+1);
+
+ P4_Mul(temp+21, (__m128i *)A+1, (__m128i *)B+1);
+
+ C[0] = w[0];
+
+ __m64 s1, s2, s3, s4;
+
+ __m64 w1 = _mm_cvtsi32_si64(w[1]);
+ __m64 w4 = mw[2];
+ __m64 w6 = mw[3];
+ __m64 w8 = mw[4];
+ __m64 w10 = mw[5];
+ __m64 w12 = mw[6];
+ __m64 w14 = mw[7];
+ __m64 w16 = mw[8];
+ __m64 w18 = mw[9];
+ __m64 w20 = mw[10];
+ __m64 w22 = mw[11];
+ __m64 w26 = _mm_cvtsi32_si64(w[26]);
+ __m64 w27 = _mm_cvtsi32_si64(w[27]);
+
+ __m64 x0 = _mm_cvtsi32_si64(x[0]);
+ __m64 x1 = _mm_cvtsi32_si64(x[1]);
+ __m64 x4 = mx[2];
+ __m64 x6 = mx[3];
+ __m64 x8 = mx[4];
+ __m64 x10 = mx[5];
+ __m64 x12 = mx[6];
+ __m64 x14 = mx[7];
+ __m64 x16 = mx[8];
+ __m64 x18 = mx[9];
+ __m64 x20 = mx[10];
+ __m64 x22 = mx[11];
+ __m64 x26 = _mm_cvtsi32_si64(x[26]);
+ __m64 x27 = _mm_cvtsi32_si64(x[27]);
+
+ __m64 y0 = _mm_cvtsi32_si64(y[0]);
+ __m64 y1 = _mm_cvtsi32_si64(y[1]);
+ __m64 y4 = my[2];
+ __m64 y6 = my[3];
+ __m64 y8 = my[4];
+ __m64 y10 = my[5];
+ __m64 y12 = my[6];
+ __m64 y14 = my[7];
+ __m64 y16 = my[8];
+ __m64 y18 = my[9];
+ __m64 y20 = my[10];
+ __m64 y22 = my[11];
+ __m64 y26 = _mm_cvtsi32_si64(y[26]);
+ __m64 y27 = _mm_cvtsi32_si64(y[27]);
+
+ __m64 z0 = _mm_cvtsi32_si64(z[0]);
+ __m64 z1 = _mm_cvtsi32_si64(z[1]);
+ __m64 z4 = mz[2];
+ __m64 z6 = mz[3];
+ __m64 z8 = mz[4];
+ __m64 z10 = mz[5];
+ __m64 z12 = mz[6];
+ __m64 z14 = mz[7];
+ __m64 z16 = mz[8];
+ __m64 z18 = mz[9];
+ __m64 z20 = mz[10];
+ __m64 z22 = mz[11];
+ __m64 z26 = _mm_cvtsi32_si64(z[26]);
+
+ s1 = _mm_add_si64(w1, w4);
+ C[1] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w6, w8);
+ s1 = _mm_add_si64(s1, s2);
+ C[2] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w10, w12);
+ s1 = _mm_add_si64(s1, s2);
+ C[3] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x0, y0);
+ s2 = _mm_add_si64(w14, w16);
+ s1 = _mm_add_si64(s1, s3);
+ s1 = _mm_add_si64(s1, s2);
+ C[4] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x1, y1);
+ s4 = _mm_add_si64(x4, y4);
+ s1 = _mm_add_si64(s1, w18);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, w20);
+ s1 = _mm_add_si64(s1, s3);
+ C[5] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x6, y6);
+ s4 = _mm_add_si64(x8, y8);
+ s1 = _mm_add_si64(s1, w22);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, w26);
+ s1 = _mm_add_si64(s1, s3);
+ C[6] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x10, y10);
+ s4 = _mm_add_si64(x12, y12);
+ s1 = _mm_add_si64(s1, w27);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, s3);
+ C[7] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x14, y14);
+ s4 = _mm_add_si64(x16, y16);
+ s1 = _mm_add_si64(s1, z0);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, s3);
+ C[8] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x18, y18);
+ s4 = _mm_add_si64(x20, y20);
+ s1 = _mm_add_si64(s1, z1);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, z4);
+ s1 = _mm_add_si64(s1, s3);
+ C[9] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x22, y22);
+ s4 = _mm_add_si64(x26, y26);
+ s1 = _mm_add_si64(s1, z6);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, z8);
+ s1 = _mm_add_si64(s1, s3);
+ C[10] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x27, y27);
+ s1 = _mm_add_si64(s1, z10);
+ s1 = _mm_add_si64(s1, z12);
+ s1 = _mm_add_si64(s1, s3);
+ C[11] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(z14, z16);
+ s1 = _mm_add_si64(s1, s3);
+ C[12] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(z18, z20);
+ s1 = _mm_add_si64(s1, s3);
+ C[13] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(z22, z26);
+ s1 = _mm_add_si64(s1, s3);
+ C[14] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ C[15] = z[27] + _mm_cvtsi64_si32(s1);
+ _mm_empty();
+}
+
+void P4Optimized::Multiply8Bottom(word *C, const word *A, const word *B)
+{
+ __m128i temp[21];
+ const word *w = (word *)temp;
+ const __m64 *mw = (__m64 *)w;
+ const word *x = (word *)temp+7*4;
+ const __m64 *mx = (__m64 *)x;
+ const word *y = (word *)temp+7*4*2;
+ const __m64 *my = (__m64 *)y;
+
+ P4_Mul(temp, (__m128i *)A, (__m128i *)B);
+
+ P4_Mul(temp+7, (__m128i *)A+1, (__m128i *)B);
+
+ P4_Mul(temp+14, (__m128i *)A, (__m128i *)B+1);
+
+ C[0] = w[0];
+
+ __m64 s1, s2, s3, s4;
+
+ __m64 w1 = _mm_cvtsi32_si64(w[1]);
+ __m64 w4 = mw[2];
+ __m64 w6 = mw[3];
+ __m64 w8 = mw[4];
+ __m64 w10 = mw[5];
+ __m64 w12 = mw[6];
+ __m64 w14 = mw[7];
+ __m64 w16 = mw[8];
+ __m64 w18 = mw[9];
+ __m64 w20 = mw[10];
+ __m64 w22 = mw[11];
+ __m64 w26 = _mm_cvtsi32_si64(w[26]);
+
+ __m64 x0 = _mm_cvtsi32_si64(x[0]);
+ __m64 x1 = _mm_cvtsi32_si64(x[1]);
+ __m64 x4 = mx[2];
+ __m64 x6 = mx[3];
+ __m64 x8 = mx[4];
+
+ __m64 y0 = _mm_cvtsi32_si64(y[0]);
+ __m64 y1 = _mm_cvtsi32_si64(y[1]);
+ __m64 y4 = my[2];
+ __m64 y6 = my[3];
+ __m64 y8 = my[4];
+
+ s1 = _mm_add_si64(w1, w4);
+ C[1] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w6, w8);
+ s1 = _mm_add_si64(s1, s2);
+ C[2] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s2 = _mm_add_si64(w10, w12);
+ s1 = _mm_add_si64(s1, s2);
+ C[3] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x0, y0);
+ s2 = _mm_add_si64(w14, w16);
+ s1 = _mm_add_si64(s1, s3);
+ s1 = _mm_add_si64(s1, s2);
+ C[4] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x1, y1);
+ s4 = _mm_add_si64(x4, y4);
+ s1 = _mm_add_si64(s1, w18);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, w20);
+ s1 = _mm_add_si64(s1, s3);
+ C[5] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ s3 = _mm_add_si64(x6, y6);
+ s4 = _mm_add_si64(x8, y8);
+ s1 = _mm_add_si64(s1, w22);
+ s3 = _mm_add_si64(s3, s4);
+ s1 = _mm_add_si64(s1, w26);
+ s1 = _mm_add_si64(s1, s3);
+ C[6] = _mm_cvtsi64_si32(s1);
+ s1 = _mm_srli_si64(s1, 32);
+
+ C[7] = _mm_cvtsi64_si32(s1) + w[27] + x[10] + y[10] + x[12] + y[12];
+ _mm_empty();
+}
+
+#endif // #ifdef SSE2_INTRINSICS_AVAILABLE
+
+// end optimized
+
+// ********************************************************
+
+#define A0 A
+#define A1 (A+N2)
+#define B0 B
+#define B1 (B+N2)
+
+#define T0 T
+#define T1 (T+N2)
+#define T2 (T+N)
+#define T3 (T+N+N2)
+
+#define R0 R
+#define R1 (R+N2)
+#define R2 (R+N)
+#define R3 (R+N+N2)
+
+//VC60 workaround: compiler bug triggered without the extra dummy parameters
+
+// R[2*N] - result = A*B
+// T[2*N] - temporary work space
+// A[N] --- multiplier
+// B[N] --- multiplicant
+
+
+void RecursiveMultiply(word *R, word *T, const word *A, const word *B,
+ unsigned int N)
+{
+ if (LowLevel::MultiplyRecursionLimit() >= 8 && N==8)
+ LowLevel::Multiply8(R, A, B);
+ else if (LowLevel::MultiplyRecursionLimit() >= 4 && N==4)
+ LowLevel::Multiply4(R, A, B);
+ else if (N==2)
+ LowLevel::Multiply2(R, A, B);
+ else
+ {
+ const unsigned int N2 = N/2;
+ int carry;
+
+ int aComp = Compare(A0, A1, N2);
+ int bComp = Compare(B0, B1, N2);
+
+ switch (2*aComp + aComp + bComp)
+ {
+ case -4:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ LowLevel::Subtract(T1, T1, R0, N2);
+ carry = -1;
+ break;
+ case -2:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ carry = 0;
+ break;
+ case 2:
+ LowLevel::Subtract(R0, A0, A1, N2);
+ LowLevel::Subtract(R1, B1, B0, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ carry = 0;
+ break;
+ case 4:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ LowLevel::Subtract(T1, T1, R1, N2);
+ carry = -1;
+ break;
+ default:
+ SetWords(T0, 0, N);
+ carry = 0;
+ }
+
+ RecursiveMultiply(R0, T2, A0, B0, N2);
+ RecursiveMultiply(R2, T2, A1, B1, N2);
+
+ // now T[01] holds (A1-A0)*(B0-B1),R[01] holds A0*B0, R[23] holds A1*B1
+
+ carry += LowLevel::Add(T0, T0, R0, N);
+ carry += LowLevel::Add(T0, T0, R2, N);
+ carry += LowLevel::Add(R1, R1, T0, N);
+
+ Increment(R3, N2, carry);
+ }
+}
+
+
+void RecursiveSquare(word *R, word *T, const word *A, unsigned int N)
+{
+ if (LowLevel::SquareRecursionLimit() >= 4 && N==4)
+ LowLevel::Square4(R, A);
+ else if (N==2)
+ LowLevel::Square2(R, A);
+ else
+ {
+ const unsigned int N2 = N/2;
+
+ RecursiveSquare(R0, T2, A0, N2);
+ RecursiveSquare(R2, T2, A1, N2);
+ RecursiveMultiply(T0, T2, A0, A1, N2);
+
+ word carry = LowLevel::Add(R1, R1, T0, N);
+ carry += LowLevel::Add(R1, R1, T0, N);
+ Increment(R3, N2, carry);
+ }
+}
+
+
+// R[N] - bottom half of A*B
+// T[N] - temporary work space
+// A[N] - multiplier
+// B[N] - multiplicant
+
+
+void RecursiveMultiplyBottom(word *R, word *T, const word *A, const word *B,
+ unsigned int N)
+{
+ if (LowLevel::MultiplyBottomRecursionLimit() >= 8 && N==8)
+ LowLevel::Multiply8Bottom(R, A, B);
+ else if (LowLevel::MultiplyBottomRecursionLimit() >= 4 && N==4)
+ LowLevel::Multiply4Bottom(R, A, B);
+ else if (N==2)
+ LowLevel::Multiply2Bottom(R, A, B);
+ else
+ {
+ const unsigned int N2 = N/2;
+
+ RecursiveMultiply(R, T, A0, B0, N2);
+ RecursiveMultiplyBottom(T0, T1, A1, B0, N2);
+ LowLevel::Add(R1, R1, T0, N2);
+ RecursiveMultiplyBottom(T0, T1, A0, B1, N2);
+ LowLevel::Add(R1, R1, T0, N2);
+ }
+}
+
+
+void RecursiveMultiplyTop(word *R, word *T, const word *L, const word *A,
+ const word *B, unsigned int N)
+{
+ if (N==4)
+ {
+ LowLevel::Multiply4(T, A, B);
+ memcpy(R, T+4, 4*WORD_SIZE);
+ }
+ else if (N==2)
+ {
+ LowLevel::Multiply2(T, A, B);
+ memcpy(R, T+2, 2*WORD_SIZE);
+ }
+ else
+ {
+ const unsigned int N2 = N/2;
+ int carry;
+
+ int aComp = Compare(A0, A1, N2);
+ int bComp = Compare(B0, B1, N2);
+
+ switch (2*aComp + aComp + bComp)
+ {
+ case -4:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ LowLevel::Subtract(T1, T1, R0, N2);
+ carry = -1;
+ break;
+ case -2:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ carry = 0;
+ break;
+ case 2:
+ LowLevel::Subtract(R0, A0, A1, N2);
+ LowLevel::Subtract(R1, B1, B0, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ carry = 0;
+ break;
+ case 4:
+ LowLevel::Subtract(R0, A1, A0, N2);
+ LowLevel::Subtract(R1, B0, B1, N2);
+ RecursiveMultiply(T0, T2, R0, R1, N2);
+ LowLevel::Subtract(T1, T1, R1, N2);
+ carry = -1;
+ break;
+ default:
+ SetWords(T0, 0, N);
+ carry = 0;
+ }
+
+ RecursiveMultiply(T2, R0, A1, B1, N2);
+
+ // now T[01] holds (A1-A0)*(B0-B1), T[23] holds A1*B1
+
+ word c2 = LowLevel::Subtract(R0, L+N2, L, N2);
+ c2 += LowLevel::Subtract(R0, R0, T0, N2);
+ word t = (Compare(R0, T2, N2) == -1);
+
+ carry += t;
+ carry += Increment(R0, N2, c2+t);
+ carry += LowLevel::Add(R0, R0, T1, N2);
+ carry += LowLevel::Add(R0, R0, T3, N2);
+
+ CopyWords(R1, T3, N2);
+ Increment(R1, N2, carry);
+ }
+}
+
+
+inline word Add(word *C, const word *A, const word *B, unsigned int N)
+{
+ return LowLevel::Add(C, A, B, N);
+}
+
+inline word Subtract(word *C, const word *A, const word *B, unsigned int N)
+{
+ return LowLevel::Subtract(C, A, B, N);
+}
+
+inline void Multiply(word *R, word *T, const word *A, const word *B,
+ unsigned int N)
+{
+ RecursiveMultiply(R, T, A, B, N);
+}
+
+inline void Square(word *R, word *T, const word *A, unsigned int N)
+{
+ RecursiveSquare(R, T, A, N);
+}
+
+
+void AsymmetricMultiply(word *R, word *T, const word *A, unsigned int NA,
+ const word *B, unsigned int NB)
+{
+ if (NA == NB)
+ {
+ if (A == B)
+ Square(R, T, A, NA);
+ else
+ Multiply(R, T, A, B, NA);
+
+ return;
+ }
+
+ if (NA > NB)
+ {
+ STL::swap(A, B);
+ STL::swap(NA, NB);
+ }
+
+ 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;
+ }
+ }
+
+ Multiply(R, T, A, B, NA);
+ CopyWords(T+2*NA, R+NA, NA);
+
+ unsigned i;
+
+ for (i=2*NA; i<NB; i+=2*NA)
+ Multiply(T+NA+i, T, A, B+i, NA);
+ for (i=NA; i<NB; i+=2*NA)
+ Multiply(R+i, T, A, B+i, NA);
+
+ if (Add(R+NA, R+NA, T+2*NA, NB-NA))
+ Increment(R+NB, NA);
+}
+
+
+void PositiveMultiply(Integer& product, const Integer& a, const Integer& b)
+{
+ unsigned int aSize = RoundupSize(a.WordCount());
+ unsigned int bSize = RoundupSize(b.WordCount());
+
+ product.reg_.CleanNew(RoundupSize(aSize + bSize));
+ product.sign_ = Integer::POSITIVE;
+
+ AlignedWordBlock workspace(aSize + bSize);
+ AsymmetricMultiply(product.reg_.get_buffer(), workspace.get_buffer(),
+ a.reg_.get_buffer(), aSize, b.reg_.get_buffer(), bSize);
+}
+
+void Multiply(Integer &product, const Integer &a, const Integer &b)
+{
+ PositiveMultiply(product, a, b);
+
+ if (a.NotNegative() != b.NotNegative())
+ product.Negate();
+}
+
+
+static inline unsigned int EvenWordCount(const word *X, unsigned int N)
+{
+ while (N && X[N-2]==0 && X[N-1]==0)
+ N-=2;
+ return N;
+}
+
+
+unsigned int AlmostInverse(word *R, word *T, const word *A, unsigned int NA,
+ const word *M, unsigned int N)
+{
+ word *b = T;
+ word *c = T+N;
+ word *f = T+2*N;
+ word *g = T+3*N;
+ unsigned int bcLen=2, fgLen=EvenWordCount(M, N);
+ unsigned int k=0, s=0;
+
+ 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);
+ if (c[bcLen-1]) bcLen+=2;
+ ShiftWordsLeftByWords(c, bcLen, 1);
+ k+=WORD_BITS;
+ t=f[0];
+ }
+
+ unsigned int i=0;
+ while (t%2 == 0)
+ {
+ t>>=1;
+ i++;
+ }
+ k+=i;
+
+ if (t==1 && f[1]==0 && EvenWordCount(f, fgLen)==2)
+ {
+ if (s%2==0)
+ CopyWords(R, b, N);
+ else
+ Subtract(R, M, b, N);
+ return k;
+ }
+
+ ShiftWordsRightByBits(f, fgLen, i);
+ t=ShiftWordsLeftByBits(c, bcLen, i);
+ if (t)
+ {
+ c[bcLen] = t;
+ bcLen+=2;
+ }
+
+ if (f[fgLen-2]==0 && g[fgLen-2]==0 && f[fgLen-1]==0 && g[fgLen-1]==0)
+ fgLen-=2;
+
+ if (Compare(f, g, fgLen)==-1)
+ {
+ STL::swap(f, g);
+ STL::swap(b, c);
+ s++;
+ }
+
+ Subtract(f, f, g, fgLen);
+
+ if (Add(b, b, c, bcLen))
+ {
+ b[bcLen] = 1;
+ bcLen+=2;
+ }
+ }
+}
+
+// R[N] - result = A/(2^k) mod M
+// A[N] - input
+// M[N] - modulus
+
+void DivideByPower2Mod(word *R, const word *A, unsigned int k, const word *M,
+ unsigned int 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, unsigned int k, const word *M,
+ unsigned int N)
+{
+ CopyWords(R, A, N);
+
+ while (k--)
+ if (ShiftWordsLeftByBits(R, N, 1) || Compare(R, M, N)>=0)
+ Subtract(R, R, M, N);
+}
+
+
+// ********** end of integer needs
+
+
+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_.get_buffer(), t.reg_.get_buffer(), reg_.size());
+}
+
+
+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<WORD_BITS, unsigned long>(value));
+}
+
+
+Integer::Integer(Sign s, word high, word low)
+ : reg_(2), sign_(s)
+{
+ reg_[0] = low;
+ reg_[1] = high;
+}
+
+
+Integer::Integer(word value, unsigned int length)
+ : reg_(RoundupSize(length)), sign_(POSITIVE)
+{
+ reg_[0] = value;
+ SetWords(reg_ + 1, 0, reg_.size() - 1);
+}
+
+
+Integer::Integer(const byte *encodedInteger, unsigned int byteCount,
+ Signedness s)
+{
+ Decode(encodedInteger, byteCount, s);
+}
+
+class BadBER {};
+
+// BER Decode Source
+Integer::Integer(Source& source)
+ : reg_(2), sign_(POSITIVE)
+{
+ Decode(source);
+}
+
+void Integer::Decode(Source& source)
+{
+ byte b = source.next();
+ if (b != INTEGER) {
+ source.SetError(INTEGER_E);
+ return;
+ }
+
+ word32 length = GetLength(source);
+ if (length == 0 || source.GetError().What()) return;
+
+ if ( (b = source.next()) == 0x00)
+ length--;
+ else
+ source.prev();
+
+ if (source.IsLeft(length) == false) return;
+
+ unsigned int words = (length + WORD_SIZE - 1) / WORD_SIZE;
+ words = RoundupSize(words);
+ if (words > reg_.size()) reg_.CleanNew(words);
+
+ for (int j = length; j > 0; j--) {
+ b = source.next();
+ reg_ [(j-1) / WORD_SIZE] |= (word)b << ((j-1) % WORD_SIZE) * 8;
+ }
+}
+
+
+void Integer::Decode(const byte* input, unsigned int inputLen, Signedness s)
+{
+ unsigned int idx(0);
+ byte b = 0;
+ if (inputLen>0)
+ b = input[idx]; // peek
+ sign_ = ((s==SIGNED) && (b & 0x80)) ? NEGATIVE : POSITIVE;
+
+ while (inputLen>0 && (sign_==POSITIVE ? b==0 : b==0xff))
+ {
+ idx++; // skip
+ if (--inputLen>0)
+ b = input[idx]; // peek
+ }
+
+ reg_.CleanNew(RoundupSize(BytesToWords(inputLen)));
+
+ for (unsigned int i=inputLen; i > 0; i--)
+ {
+ b = input[idx++];
+ reg_[(i-1)/WORD_SIZE] |= (word)b << ((i-1)%WORD_SIZE)*8;
+ }
+
+ if (sign_ == NEGATIVE)
+ {
+ for (unsigned i=inputLen; i<reg_.size()*WORD_SIZE; i++)
+ reg_[i/WORD_SIZE] |= (word)0xff << (i%WORD_SIZE)*8;
+ TwosComplement(reg_.get_buffer(), reg_.size());
+ }
+}
+
+
+unsigned int Integer::Encode(byte* output, unsigned int outputLen,
+ Signedness signedness) const
+{
+ unsigned int idx(0);
+ if (signedness == UNSIGNED || NotNegative())
+ {
+ for (unsigned int i=outputLen; i > 0; i--)
+ output[idx++] = GetByte(i-1);
+ }
+ else
+ {
+ // take two's complement of *this
+ Integer temp = Integer::Power2(8*max(ByteCount(), outputLen)) + *this;
+ for (unsigned i=0; i<outputLen; i++)
+ output[idx++] = temp.GetByte(outputLen-i-1);
+ }
+ return outputLen;
+}
+
+
+static Integer* zero = 0;
+
+const Integer &Integer::Zero()
+{
+ if (!zero)
+ zero = NEW_TC Integer;
+ return *zero;
+}
+
+
+static Integer* one = 0;
+
+const Integer &Integer::One()
+{
+ if (!one)
+ one = NEW_TC Integer(1,2);
+ return *one;
+}
+
+
+// Clean up static singleton holders, not a leak, but helpful to have gone
+// when checking for leaks
+void CleanUp()
+{
+ tcDelete(one);
+ tcDelete(zero);
+
+ // In case user calls more than once, prevent seg fault
+ one = 0;
+ zero = 0;
+}
+
+Integer::Integer(RandomNumberGenerator& rng, const Integer& min,
+ const Integer& max)
+{
+ Randomize(rng, min, max);
+}
+
+
+void Integer::Randomize(RandomNumberGenerator& rng, unsigned int nbits)
+{
+ const unsigned int nbytes = nbits/8 + 1;
+ ByteBlock buf(nbytes);
+ rng.GenerateBlock(buf.get_buffer(), nbytes);
+ if (nbytes)
+ buf[0] = (byte)Crop(buf[0], nbits % 8);
+ Decode(buf.get_buffer(), nbytes, UNSIGNED);
+}
+
+void Integer::Randomize(RandomNumberGenerator& rng, const Integer& min,
+ const Integer& max)
+{
+ Integer range = max - min;
+ const unsigned int nbits = range.BitCount();
+
+ do
+ {
+ Randomize(rng, nbits);
+ }
+ while (*this > range);
+
+ *this += min;
+}
+
+
+Integer Integer::Power2(unsigned int e)
+{
+ Integer r((word)0, BitsToWords(e + 1));
+ r.SetBit(e);
+ return r;
+}
+
+
+void Integer::SetBit(unsigned int 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));
+ }
+}
+
+
+void Integer::SetByte(unsigned int 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));
+}
+
+
+void Integer::Negate()
+{
+ if (!!(*this)) // don't flip sign if *this==0
+ sign_ = Sign(1 - sign_);
+}
+
+
+bool Integer::operator!() const
+{
+ return IsNegative() ? false : (reg_[0]==0 && WordCount()==0);
+}
+
+
+Integer& Integer::operator=(const Integer& t)
+{
+ if (this != &t)
+ {
+ reg_.New(RoundupSize(t.WordCount()));
+ CopyWords(reg_.get_buffer(), t.reg_.get_buffer(), reg_.size());
+ sign_ = t.sign_;
+ }
+ return *this;
+}
+
+
+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::operator-() const
+{
+ Integer result(*this);
+ result.Negate();
+ return result;
+}
+
+
+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++()
+{
+ if (NotNegative())
+ {
+ if (Increment(reg_.get_buffer(), reg_.size()))
+ {
+ reg_.CleanGrow(2*reg_.size());
+ reg_[reg_.size()/2]=1;
+ }
+ }
+ else
+ {
+ word borrow = Decrement(reg_.get_buffer(), reg_.size());
+ (void)borrow; // shut up compiler
+ if (WordCount()==0)
+ *this = Zero();
+ }
+ return *this;
+}
+
+Integer& Integer::operator--()
+{
+ if (IsNegative())
+ {
+ if (Increment(reg_.get_buffer(), reg_.size()))
+ {
+ reg_.CleanGrow(2*reg_.size());
+ reg_[reg_.size()/2]=1;
+ }
+ }
+ else
+ {
+ if (Decrement(reg_.get_buffer(), reg_.size()))
+ *this = -One();
+ }
+ return *this;
+}
+
+
+Integer& Integer::operator<<=(unsigned int n)
+{
+ const unsigned int wordCount = WordCount();
+ const unsigned int shiftWords = n / WORD_BITS;
+ const unsigned int shiftBits = n % WORD_BITS;
+
+ reg_.CleanGrow(RoundupSize(wordCount+BitsToWords(n)));
+ ShiftWordsLeftByWords(reg_.get_buffer(), wordCount + shiftWords,
+ shiftWords);
+ ShiftWordsLeftByBits(reg_+shiftWords, wordCount+BitsToWords(shiftBits),
+ shiftBits);
+ return *this;
+}
+
+Integer& Integer::operator>>=(unsigned int n)
+{
+ const unsigned int wordCount = WordCount();
+ const unsigned int shiftWords = n / WORD_BITS;
+ const unsigned int shiftBits = n % WORD_BITS;
+
+ ShiftWordsRightByWords(reg_.get_buffer(), wordCount, shiftWords);
+ if (wordCount > shiftWords)
+ ShiftWordsRightByBits(reg_.get_buffer(), wordCount-shiftWords,
+ shiftBits);
+ if (IsNegative() && WordCount()==0) // avoid -0
+ *this = Zero();
+ return *this;
+}
+
+
+void PositiveAdd(Integer& sum, const Integer& a, const Integer& b)
+{
+ word carry;
+ if (a.reg_.size() == b.reg_.size())
+ carry = Add(sum.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), a.reg_.size());
+ else if (a.reg_.size() > b.reg_.size())
+ {
+ carry = Add(sum.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), 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_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), 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_.get_buffer(), b.reg_.get_buffer(), aSize) >= 0)
+ {
+ Subtract(diff.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), aSize);
+ diff.sign_ = Integer::POSITIVE;
+ }
+ else
+ {
+ Subtract(diff.reg_.get_buffer(), b.reg_.get_buffer(),
+ a.reg_.get_buffer(), aSize);
+ diff.sign_ = Integer::NEGATIVE;
+ }
+ }
+ else if (aSize > bSize)
+ {
+ word borrow = Subtract(diff.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), bSize);
+ CopyWords(diff.reg_+bSize, a.reg_+bSize, aSize-bSize);
+ borrow = Decrement(diff.reg_+bSize, aSize-bSize, borrow);
+ diff.sign_ = Integer::POSITIVE;
+ }
+ else
+ {
+ word borrow = Subtract(diff.reg_.get_buffer(), b.reg_.get_buffer(),
+ a.reg_.get_buffer(), aSize);
+ CopyWords(diff.reg_+aSize, b.reg_+aSize, bSize-aSize);
+ borrow = Decrement(diff.reg_+aSize, bSize-aSize, borrow);
+ diff.sign_ = Integer::NEGATIVE;
+ }
+}
+
+
+unsigned int Integer::MinEncodedSize(Signedness signedness) const
+{
+ unsigned int outputLen = max(1U, ByteCount());
+ if (signedness == UNSIGNED)
+ return outputLen;
+ if (NotNegative() && (GetByte(outputLen-1) & 0x80))
+ outputLen++;
+ if (IsNegative() && *this < -Power2(outputLen*8-1))
+ outputLen++;
+ return outputLen;
+}
+
+
+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);
+ }
+}
+
+
+int Integer::PositiveCompare(const Integer& t) const
+{
+ unsigned size = WordCount(), tSize = t.WordCount();
+
+ if (size == tSize)
+ return TaoCrypt::Compare(reg_.get_buffer(), t.reg_.get_buffer(), size);
+ else
+ return size > tSize ? 1 : -1;
+}
+
+
+bool Integer::GetBit(unsigned int n) const
+{
+ if (n/WORD_BITS >= reg_.size())
+ return 0;
+ else
+ return bool((reg_[n/WORD_BITS] >> (n % WORD_BITS)) & 1);
+}
+
+
+unsigned long Integer::GetBits(unsigned int i, unsigned int n) const
+{
+ unsigned long v = 0;
+ for (unsigned int j=0; j<n; j++)
+ v |= GetBit(i+j) << j;
+ return v;
+}
+
+
+byte Integer::GetByte(unsigned int n) const
+{
+ if (n/WORD_SIZE >= reg_.size())
+ return 0;
+ else
+ return byte(reg_[n/WORD_SIZE] >> ((n%WORD_SIZE)*8));
+}
+
+
+unsigned int Integer::BitCount() const
+{
+ unsigned wordCount = WordCount();
+ if (wordCount)
+ return (wordCount-1)*WORD_BITS + BitPrecision(reg_[wordCount-1]);
+ else
+ return 0;
+}
+
+
+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::WordCount() const
+{
+ return CountWords(reg_.get_buffer(), reg_.size());
+}
+
+
+bool Integer::IsConvertableToLong() const
+{
+ if (ByteCount() > sizeof(long))
+ return false;
+
+ unsigned long value = reg_[0];
+ value += SafeLeftShift<WORD_BITS, unsigned long>(reg_[1]);
+
+ if (sign_ == POSITIVE)
+ return (signed long)value >= 0;
+ else
+ return -(signed long)value < 0;
+}
+
+
+signed long Integer::ConvertToLong() const
+{
+ unsigned long value = reg_[0];
+ value += SafeLeftShift<WORD_BITS, unsigned long>(reg_[1]);
+ return sign_ == POSITIVE ? value : -(signed long)value;
+}
+
+
+void Integer::Swap(Integer& a)
+{
+ reg_.Swap(a.reg_);
+ STL::swap(sign_, a.sign_);
+}
+
+
+Integer Integer::Plus(const Integer& b) const
+{
+ Integer sum((word)0, max(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::Minus(const Integer& b) const
+{
+ Integer diff((word)0, max(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::Times(const Integer &b) const
+{
+ Integer product;
+ Multiply(product, *this, b);
+ return product;
+}
+
+
+#undef A0
+#undef A1
+#undef B0
+#undef B1
+
+#undef T0
+#undef T1
+#undef T2
+#undef T3
+
+#undef R0
+#undef R1
+#undef R2
+#undef R3
+
+
+static inline void AtomicDivide(word *Q, const word *A, const word *B)
+{
+ word T[4];
+ DWord q = DivideFourWordsByTwo<word, DWord>(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
+ word P[4];
+ Portable::Multiply2(P, Q, B);
+ Add(P, P, T, 4);
+ }
+#endif
+}
+
+
+// for use by Divide(), corrects the underestimated quotient {Q1,Q0}
+static void CorrectQuotientEstimate(word *R, word *T, word *Q, const word *B,
+ unsigned int N)
+{
+ if (Q[1])
+ {
+ T[N] = T[N+1] = 0;
+ unsigned i;
+ for (i=0; i<N; i+=4)
+ LowLevel::Multiply2(T+i, Q, B+i);
+ for (i=2; i<N; i+=4)
+ if (LowLevel::Multiply2Add(T+i, Q, B+i))
+ T[i+5] += (++T[i+4]==0);
+ }
+ else
+ {
+ T[N] = LinearMultiply(T, B, Q[0], N);
+ T[N+1] = 0;
+ }
+
+ word borrow = Subtract(R, R, T, N+2);
+ (void)borrow; // shut up compiler
+
+ while (R[N] || Compare(R, B, N) >= 0)
+ {
+ R[N] -= Subtract(R, R, B, N);
+ Q[1] += (++Q[0]==0);
+ }
+}
+
+// R[NB] -------- remainder = A%B
+// Q[NA-NB+2] --- quotient = A/B
+// T[NA+2*NB+4] - temp work space
+// A[NA] -------- dividend
+// B[NB] -------- divisor
+
+
+void Divide(word* R, word* Q, word* T, const word* A, unsigned int NA,
+ const word* B, unsigned int NB)
+{
+ // 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]);
+ 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;
+ }
+
+ 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 (unsigned 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);
+}
+
+
+void PositiveDivide(Integer& remainder, Integer& quotient,
+ const Integer& a, const Integer& b)
+{
+ unsigned aSize = a.WordCount();
+ unsigned bSize = b.WordCount();
+
+ if (a.PositiveCompare(b) == -1)
+ {
+ 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;
+
+ AlignedWordBlock T(aSize+2*bSize+4);
+ Divide(remainder.reg_.get_buffer(), quotient.reg_.get_buffer(),
+ T.get_buffer(), a.reg_.get_buffer(), aSize, b.reg_.get_buffer(),
+ bSize);
+}
+
+void Integer::Divide(Integer &remainder, Integer &quotient,
+ const Integer &dividend, 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 unsigned int wordCount = BitsToWords(n);
+ if (wordCount <= a.WordCount())
+ {
+ r.reg_.resize(RoundupSize(wordCount));
+ CopyWords(r.reg_.get_buffer(), a.reg_.get_buffer(), 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_.get_buffer(), a.reg_.get_buffer(), 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 &quotient,
+ const Integer &dividend, word 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
+{
+ 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;
+}
+
+
+Integer Integer::AbsoluteValue() const
+{
+ Integer result(*this);
+ result.sign_ = POSITIVE;
+ return result;
+}
+
+
+Integer Integer::SquareRoot() const
+{
+ if (!IsPositive())
+ return Zero();
+
+ // overestimate square root
+ Integer x, y = Power2((BitCount()+1)/2);
+
+ do
+ {
+ x = y;
+ y = (x + *this/x) >> 1;
+ } while (y<x);
+
+ return x;
+}
+
+bool Integer::IsSquare() const
+{
+ Integer r = SquareRoot();
+ return *this == r.Squared();
+}
+
+bool Integer::IsUnit() const
+{
+ return (WordCount() == 1) && (reg_[0] == 1);
+}
+
+Integer Integer::MultiplicativeInverse() const
+{
+ return IsUnit() ? *this : Zero();
+}
+
+Integer a_times_b_mod_c(const Integer &x, const Integer& y, const Integer& m)
+{
+ return x*y%m;
+}
+
+Integer a_exp_b_mod_c(const Integer &x, const Integer& e, const Integer& m)
+{
+ ModularArithmetic mr(m);
+ return mr.Exponentiate(x, e);
+}
+
+Integer Integer::Gcd(const Integer &a, const Integer &b)
+{
+ return EuclideanDomainOf().Gcd(a, b);
+}
+
+Integer Integer::InverseMod(const Integer &m) const
+{
+ if (IsNegative() || *this>=m)
+ return (*this%m).InverseMod(m);
+
+ if (m.IsEven())
+ {
+ if (!m || IsEven())
+ return Zero(); // no inverse
+ if (*this == One())
+ return One();
+
+ Integer u = m.InverseMod(*this);
+ return !u ? Zero() : (m*(*this-u)+1)/(*this);
+ }
+
+ AlignedWordBlock T(m.reg_.size() * 4);
+ Integer r((word)0, m.reg_.size());
+ unsigned k = AlmostInverse(r.reg_.get_buffer(), T.get_buffer(),
+ reg_.get_buffer(), reg_.size(),
+ m.reg_.get_buffer(), m.reg_.size());
+ DivideByPower2Mod(r.reg_.get_buffer(), r.reg_.get_buffer(), k,
+ m.reg_.get_buffer(), m.reg_.size());
+ return r;
+}
+
+word Integer::InverseMod(const 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;
+}
+
+// ********* ModArith stuff
+
+const Integer& ModularArithmetic::Half(const Integer &a) const
+{
+ if (a.reg_.size()==modulus.reg_.size())
+ {
+ TaoCrypt::DivideByPower2Mod(result.reg_.begin(), a.reg_.begin(), 1,
+ modulus.reg_.begin(), a.reg_.size());
+ return result;
+ }
+ else
+ return result1 = (a.IsEven() ? (a >> 1) : ((a+modulus) >> 1));
+}
+
+const Integer& ModularArithmetic::Add(const Integer &a, const Integer &b) const
+{
+ if (a.reg_.size()==modulus.reg_.size() &&
+ b.reg_.size()==modulus.reg_.size())
+ {
+ if (TaoCrypt::Add(result.reg_.begin(), a.reg_.begin(), b.reg_.begin(),
+ a.reg_.size())
+ || Compare(result.reg_.get_buffer(), modulus.reg_.get_buffer(),
+ a.reg_.size()) >= 0)
+ {
+ TaoCrypt::Subtract(result.reg_.begin(), result.reg_.begin(),
+ modulus.reg_.begin(), a.reg_.size());
+ }
+ return result;
+ }
+ else
+ {
+ result1 = a+b;
+ if (result1 >= modulus)
+ result1 -= modulus;
+ return result1;
+ }
+}
+
+Integer& ModularArithmetic::Accumulate(Integer &a, const Integer &b) const
+{
+ if (a.reg_.size()==modulus.reg_.size() &&
+ b.reg_.size()==modulus.reg_.size())
+ {
+ if (TaoCrypt::Add(a.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), a.reg_.size())
+ || Compare(a.reg_.get_buffer(), modulus.reg_.get_buffer(),
+ a.reg_.size()) >= 0)
+ {
+ TaoCrypt::Subtract(a.reg_.get_buffer(), a.reg_.get_buffer(),
+ modulus.reg_.get_buffer(), a.reg_.size());
+ }
+ }
+ else
+ {
+ a+=b;
+ if (a>=modulus)
+ a-=modulus;
+ }
+
+ return a;
+}
+
+const Integer& ModularArithmetic::Subtract(const Integer &a,
+ const Integer &b) const
+{
+ if (a.reg_.size()==modulus.reg_.size() &&
+ b.reg_.size()==modulus.reg_.size())
+ {
+ if (TaoCrypt::Subtract(result.reg_.begin(), a.reg_.begin(),
+ b.reg_.begin(), a.reg_.size()))
+ TaoCrypt::Add(result.reg_.begin(), result.reg_.begin(),
+ modulus.reg_.begin(), a.reg_.size());
+ return result;
+ }
+ else
+ {
+ result1 = a-b;
+ if (result1.IsNegative())
+ result1 += modulus;
+ return result1;
+ }
+}
+
+Integer& ModularArithmetic::Reduce(Integer &a, const Integer &b) const
+{
+ if (a.reg_.size()==modulus.reg_.size() &&
+ b.reg_.size()==modulus.reg_.size())
+ {
+ if (TaoCrypt::Subtract(a.reg_.get_buffer(), a.reg_.get_buffer(),
+ b.reg_.get_buffer(), a.reg_.size()))
+ TaoCrypt::Add(a.reg_.get_buffer(), a.reg_.get_buffer(),
+ modulus.reg_.get_buffer(), a.reg_.size());
+ }
+ else
+ {
+ a-=b;
+ if (a.IsNegative())
+ a+=modulus;
+ }
+
+ return a;
+}
+
+const Integer& ModularArithmetic::Inverse(const Integer &a) const
+{
+ if (!a)
+ return a;
+
+ CopyWords(result.reg_.begin(), modulus.reg_.begin(), modulus.reg_.size());
+ if (TaoCrypt::Subtract(result.reg_.begin(), result.reg_.begin(),
+ a.reg_.begin(), a.reg_.size()))
+ Decrement(result.reg_.begin()+a.reg_.size(), 1,
+ modulus.reg_.size()-a.reg_.size());
+
+ return result;
+}
+
+Integer ModularArithmetic::CascadeExponentiate(const Integer &x,
+ const Integer &e1, const Integer &y, const Integer &e2) const
+{
+ if (modulus.IsOdd())
+ {
+ MontgomeryRepresentation dr(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 (modulus.IsOdd())
+ {
+ MontgomeryRepresentation dr(modulus);
+ dr.SimultaneousExponentiate(results, dr.ConvertIn(base), exponents,
+ exponentsCount);
+ for (unsigned int i=0; i<exponentsCount; i++)
+ results[i] = dr.ConvertOut(results[i]);
+ }
+ else
+ AbstractRing::SimultaneousExponentiate(results, base,
+ exponents, exponentsCount);
+}
+
+
+// ********************************************************
+
+#define A0 A
+#define A1 (A+N2)
+#define B0 B
+#define B1 (B+N2)
+
+#define T0 T
+#define T1 (T+N2)
+#define T2 (T+N)
+#define T3 (T+N+N2)
+
+#define R0 R
+#define R1 (R+N2)
+#define R2 (R+N)
+#define R3 (R+N+N2)
+
+
+inline void MultiplyBottom(word *R, word *T, const word *A, const word *B,
+ unsigned int N)
+{
+ RecursiveMultiplyBottom(R, T, A, B, N);
+}
+
+inline void MultiplyTop(word *R, word *T, const word *L, const word *A,
+ const word *B, unsigned int N)
+{
+ RecursiveMultiplyTop(R, T, L, A, B, N);
+}
+
+
+// R[N] --- result = X/(2**(WORD_BITS*N)) mod M
+// T[3*N] - temporary work space
+// X[2*N] - number to be reduced
+// M[N] --- modulus
+// U[N] --- multiplicative inverse of M mod 2**(WORD_BITS*N)
+
+void MontgomeryReduce(word *R, word *T, const word *X, const word *M,
+ const word *U, unsigned int N)
+{
+ MultiplyBottom(R, T, X, U, N);
+ MultiplyTop(T, T+N, X, R, M, N);
+ word borrow = Subtract(T, X+N, T, N);
+ // defend against timing attack by doing this Add even when not needed
+ word carry = Add(T+N, T, M, N);
+ (void)carry; // shut up compiler
+ CopyWords(R, T + (borrow ? N : 0), N);
+}
+
+// R[N] ----- result = A inverse mod 2**(WORD_BITS*N)
+// T[3*N/2] - temporary work space
+// A[N] ----- an odd number as input
+
+void RecursiveInverseModPower2(word *R, word *T, const word *A, unsigned int N)
+{
+ if (N==2)
+ {
+ T[0] = AtomicInverseModPower2(A[0]);
+ T[1] = 0;
+ LowLevel::Multiply2Bottom(T+2, T, A);
+ TwosComplement(T+2, 2);
+ Increment(T+2, 2, 2);
+ LowLevel::Multiply2Bottom(R, T, T+2);
+ }
+ else
+ {
+ const unsigned int N2 = N/2;
+ RecursiveInverseModPower2(R0, T0, A0, N2);
+ T0[0] = 1;
+ SetWords(T0+1, 0, N2-1);
+ MultiplyTop(R1, T1, T0, R0, A0, N2);
+ MultiplyBottom(T0, T1, R0, A1, N2);
+ Add(T0, R1, T0, N2);
+ TwosComplement(T0, N2);
+ MultiplyBottom(R1, T1, R0, T0, N2);
+ }
+}
+
+
+#undef A0
+#undef A1
+#undef B0
+#undef B1
+
+#undef T0
+#undef T1
+#undef T2
+#undef T3
+
+#undef R0
+#undef R1
+#undef R2
+#undef R3
+
+
+// modulus must be odd
+MontgomeryRepresentation::MontgomeryRepresentation(const Integer &m)
+ : ModularArithmetic(m),
+ u((word)0, modulus.reg_.size()),
+ workspace(5*modulus.reg_.size())
+{
+ RecursiveInverseModPower2(u.reg_.get_buffer(), workspace.get_buffer(),
+ modulus.reg_.get_buffer(), modulus.reg_.size());
+}
+
+const Integer& MontgomeryRepresentation::Multiply(const Integer &a,
+ const Integer &b) const
+{
+ word *const T = workspace.begin();
+ word *const R = result.reg_.begin();
+ const unsigned int N = modulus.reg_.size();
+
+ AsymmetricMultiply(T, T+2*N, a.reg_.get_buffer(), a.reg_.size(),
+ b.reg_.get_buffer(), 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, modulus.reg_.get_buffer(),
+ u.reg_.get_buffer(), N);
+ return result;
+}
+
+const Integer& MontgomeryRepresentation::Square(const Integer &a) const
+{
+ word *const T = workspace.begin();
+ word *const R = result.reg_.begin();
+ const unsigned int N = modulus.reg_.size();
+
+ TaoCrypt::Square(T, T+2*N, a.reg_.get_buffer(), a.reg_.size());
+ SetWords(T+2*a.reg_.size(), 0, 2*N-2*a.reg_.size());
+ MontgomeryReduce(R, T+2*N, T, modulus.reg_.get_buffer(),
+ u.reg_.get_buffer(), N);
+ return result;
+}
+
+Integer MontgomeryRepresentation::ConvertOut(const Integer &a) const
+{
+ word *const T = workspace.begin();
+ word *const R = result.reg_.begin();
+ const unsigned int N = modulus.reg_.size();
+
+ CopyWords(T, a.reg_.get_buffer(), a.reg_.size());
+ SetWords(T+a.reg_.size(), 0, 2*N-a.reg_.size());
+ MontgomeryReduce(R, T+2*N, T, modulus.reg_.get_buffer(),
+ u.reg_.get_buffer(), N);
+ return result;
+}
+
+const Integer& MontgomeryRepresentation::MultiplicativeInverse(
+ const Integer &a) const
+{
+// return (EuclideanMultiplicativeInverse(a, modulus)<<
+// (2*WORD_BITS*modulus.reg_.size()))%modulus;
+ word *const T = workspace.begin();
+ word *const R = result.reg_.begin();
+ const unsigned int N = modulus.reg_.size();
+
+ CopyWords(T, a.reg_.get_buffer(), a.reg_.size());
+ SetWords(T+a.reg_.size(), 0, 2*N-a.reg_.size());
+ MontgomeryReduce(R, T+2*N, T, modulus.reg_.get_buffer(),
+ u.reg_.get_buffer(), N);
+ unsigned k = AlmostInverse(R, T, R, N, modulus.reg_.get_buffer(), N);
+
+// cout << "k=" << k << " N*32=" << 32*N << endl;
+
+ if (k>N*WORD_BITS)
+ DivideByPower2Mod(R, R, k-N*WORD_BITS, modulus.reg_.get_buffer(), N);
+ else
+ MultiplyByPower2Mod(R, R, N*WORD_BITS-k, modulus.reg_.get_buffer(), N);
+
+ return result;
+}
+
+
+// mod Root stuff
+Integer ModularRoot(const Integer &a, const Integer &dp, const Integer &dq,
+ const Integer &p, const Integer &q, const Integer &u)
+{
+ Integer p2 = ModularExponentiation((a % p), dp, p);
+ Integer q2 = ModularExponentiation((a % q), dq, q);
+ return CRT(p2, p, q2, q, u);
+}
+
+Integer CRT(const Integer &xp, const Integer &p, const Integer &xq,
+ const Integer &q, const Integer &u)
+{
+ // isn't operator overloading great?
+ return p * (u * (xq-xp) % q) + xp;
+}
+
+
+#ifdef HAVE_EXPLICIT_TEMPLATE_INSTANTIATION
+#ifndef TAOCRYPT_NATIVE_DWORD_AVAILABLE
+template hword DivideThreeWordsByTwo<hword, Word>(hword*, hword, hword, Word*);
+#endif
+template word DivideThreeWordsByTwo<word, DWord>(word*, word, word, DWord*);
+#ifdef SSE2_INTRINSICS_AVAILABLE
+template class AlignedAllocator<word>;
+#endif
+#endif
+
+
+} // namespace
+