Mercurial > trustbridge > nss-cmake-static
diff nss/lib/freebl/mpi/mpmontg.c @ 0:1e5118fa0cb1
This is NSS with a Cmake Buildsyste
To compile a static NSS library for Windows we've used the
Chromium-NSS fork and added a Cmake buildsystem to compile
it statically for Windows. See README.chromium for chromium
changes and README.trustbridge for our modifications.
author | Andre Heinecke <andre.heinecke@intevation.de> |
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date | Mon, 28 Jul 2014 10:47:06 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/nss/lib/freebl/mpi/mpmontg.c Mon Jul 28 10:47:06 2014 +0200 @@ -0,0 +1,1173 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* This file implements moduluar exponentiation using Montgomery's + * method for modular reduction. This file implements the method + * described as "Improvement 2" in the paper "A Cryptogrpahic Library for + * the Motorola DSP56000" by Stephen R. Dusse' and Burton S. Kaliski Jr. + * published in "Advances in Cryptology: Proceedings of EUROCRYPT '90" + * "Lecture Notes in Computer Science" volume 473, 1991, pg 230-244, + * published by Springer Verlag. + */ + +#define MP_USING_CACHE_SAFE_MOD_EXP 1 +#include <string.h> +#include "mpi-priv.h" +#include "mplogic.h" +#include "mpprime.h" +#ifdef MP_USING_MONT_MULF +#include "montmulf.h" +#endif +#include <stddef.h> /* ptrdiff_t */ + +/* if MP_CHAR_STORE_SLOW is defined, we */ +/* need to know endianness of this platform. */ +#ifdef MP_CHAR_STORE_SLOW +#if !defined(MP_IS_BIG_ENDIAN) && !defined(MP_IS_LITTLE_ENDIAN) +#error "You must define MP_IS_BIG_ENDIAN or MP_IS_LITTLE_ENDIAN\n" \ + " if you define MP_CHAR_STORE_SLOW." +#endif +#endif + +#define STATIC + +#define MAX_ODD_INTS 32 /* 2 ** (WINDOW_BITS - 1) */ + +/*! computes T = REDC(T), 2^b == R + \param T < RN +*/ +mp_err s_mp_redc(mp_int *T, mp_mont_modulus *mmm) +{ + mp_err res; + mp_size i; + + i = (MP_USED(&mmm->N) << 1) + 1; + MP_CHECKOK( s_mp_pad(T, i) ); + for (i = 0; i < MP_USED(&mmm->N); ++i ) { + mp_digit m_i = MP_DIGIT(T, i) * mmm->n0prime; + /* T += N * m_i * (MP_RADIX ** i); */ + MP_CHECKOK( s_mp_mul_d_add_offset(&mmm->N, m_i, T, i) ); + } + s_mp_clamp(T); + + /* T /= R */ + s_mp_rshd( T, MP_USED(&mmm->N) ); + + if ((res = s_mp_cmp(T, &mmm->N)) >= 0) { + /* T = T - N */ + MP_CHECKOK( s_mp_sub(T, &mmm->N) ); +#ifdef DEBUG + if ((res = mp_cmp(T, &mmm->N)) >= 0) { + res = MP_UNDEF; + goto CLEANUP; + } +#endif + } + res = MP_OKAY; +CLEANUP: + return res; +} + +#if !defined(MP_MONT_USE_MP_MUL) + +/*! c <- REDC( a * b ) mod N + \param a < N i.e. "reduced" + \param b < N i.e. "reduced" + \param mmm modulus N and n0' of N +*/ +mp_err s_mp_mul_mont(const mp_int *a, const mp_int *b, mp_int *c, + mp_mont_modulus *mmm) +{ + mp_digit *pb; + mp_digit m_i; + mp_err res; + mp_size ib; /* "index b": index of current digit of B */ + mp_size useda, usedb; + + ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG); + + if (MP_USED(a) < MP_USED(b)) { + const mp_int *xch = b; /* switch a and b, to do fewer outer loops */ + b = a; + a = xch; + } + + MP_USED(c) = 1; MP_DIGIT(c, 0) = 0; + ib = (MP_USED(&mmm->N) << 1) + 1; + if((res = s_mp_pad(c, ib)) != MP_OKAY) + goto CLEANUP; + + useda = MP_USED(a); + pb = MP_DIGITS(b); + s_mpv_mul_d(MP_DIGITS(a), useda, *pb++, MP_DIGITS(c)); + s_mp_setz(MP_DIGITS(c) + useda + 1, ib - (useda + 1)); + m_i = MP_DIGIT(c, 0) * mmm->n0prime; + s_mp_mul_d_add_offset(&mmm->N, m_i, c, 0); + + /* Outer loop: Digits of b */ + usedb = MP_USED(b); + for (ib = 1; ib < usedb; ib++) { + mp_digit b_i = *pb++; + + /* Inner product: Digits of a */ + if (b_i) + s_mpv_mul_d_add_prop(MP_DIGITS(a), useda, b_i, MP_DIGITS(c) + ib); + m_i = MP_DIGIT(c, ib) * mmm->n0prime; + s_mp_mul_d_add_offset(&mmm->N, m_i, c, ib); + } + if (usedb < MP_USED(&mmm->N)) { + for (usedb = MP_USED(&mmm->N); ib < usedb; ++ib ) { + m_i = MP_DIGIT(c, ib) * mmm->n0prime; + s_mp_mul_d_add_offset(&mmm->N, m_i, c, ib); + } + } + s_mp_clamp(c); + s_mp_rshd( c, MP_USED(&mmm->N) ); /* c /= R */ + if (s_mp_cmp(c, &mmm->N) >= 0) { + MP_CHECKOK( s_mp_sub(c, &mmm->N) ); + } + res = MP_OKAY; + +CLEANUP: + return res; +} +#endif + +STATIC +mp_err s_mp_to_mont(const mp_int *x, mp_mont_modulus *mmm, mp_int *xMont) +{ + mp_err res; + + /* xMont = x * R mod N where N is modulus */ + MP_CHECKOK( mp_copy( x, xMont ) ); + MP_CHECKOK( s_mp_lshd( xMont, MP_USED(&mmm->N) ) ); /* xMont = x << b */ + MP_CHECKOK( mp_div(xMont, &mmm->N, 0, xMont) ); /* mod N */ +CLEANUP: + return res; +} + +#ifdef MP_USING_MONT_MULF + +/* the floating point multiply is already cache safe, + * don't turn on cache safe unless we specifically + * force it */ +#ifndef MP_FORCE_CACHE_SAFE +#undef MP_USING_CACHE_SAFE_MOD_EXP +#endif + +unsigned int mp_using_mont_mulf = 1; + +/* computes montgomery square of the integer in mResult */ +#define SQR \ + conv_i32_to_d32_and_d16(dm1, d16Tmp, mResult, nLen); \ + mont_mulf_noconv(mResult, dm1, d16Tmp, \ + dTmp, dn, MP_DIGITS(modulus), nLen, dn0) + +/* computes montgomery product of x and the integer in mResult */ +#define MUL(x) \ + conv_i32_to_d32(dm1, mResult, nLen); \ + mont_mulf_noconv(mResult, dm1, oddPowers[x], \ + dTmp, dn, MP_DIGITS(modulus), nLen, dn0) + +/* Do modular exponentiation using floating point multiply code. */ +mp_err mp_exptmod_f(const mp_int * montBase, + const mp_int * exponent, + const mp_int * modulus, + mp_int * result, + mp_mont_modulus *mmm, + int nLen, + mp_size bits_in_exponent, + mp_size window_bits, + mp_size odd_ints) +{ + mp_digit *mResult; + double *dBuf = 0, *dm1, *dn, *dSqr, *d16Tmp, *dTmp; + double dn0; + mp_size i; + mp_err res; + int expOff; + int dSize = 0, oddPowSize, dTmpSize; + mp_int accum1; + double *oddPowers[MAX_ODD_INTS]; + + /* function for computing n0prime only works if n0 is odd */ + + MP_DIGITS(&accum1) = 0; + + for (i = 0; i < MAX_ODD_INTS; ++i) + oddPowers[i] = 0; + + MP_CHECKOK( mp_init_size(&accum1, 3 * nLen + 2) ); + + mp_set(&accum1, 1); + MP_CHECKOK( s_mp_to_mont(&accum1, mmm, &accum1) ); + MP_CHECKOK( s_mp_pad(&accum1, nLen) ); + + oddPowSize = 2 * nLen + 1; + dTmpSize = 2 * oddPowSize; + dSize = sizeof(double) * (nLen * 4 + 1 + + ((odd_ints + 1) * oddPowSize) + dTmpSize); + dBuf = (double *)malloc(dSize); + dm1 = dBuf; /* array of d32 */ + dn = dBuf + nLen; /* array of d32 */ + dSqr = dn + nLen; /* array of d32 */ + d16Tmp = dSqr + nLen; /* array of d16 */ + dTmp = d16Tmp + oddPowSize; + + for (i = 0; i < odd_ints; ++i) { + oddPowers[i] = dTmp; + dTmp += oddPowSize; + } + mResult = (mp_digit *)(dTmp + dTmpSize); /* size is nLen + 1 */ + + /* Make dn and dn0 */ + conv_i32_to_d32(dn, MP_DIGITS(modulus), nLen); + dn0 = (double)(mmm->n0prime & 0xffff); + + /* Make dSqr */ + conv_i32_to_d32_and_d16(dm1, oddPowers[0], MP_DIGITS(montBase), nLen); + mont_mulf_noconv(mResult, dm1, oddPowers[0], + dTmp, dn, MP_DIGITS(modulus), nLen, dn0); + conv_i32_to_d32(dSqr, mResult, nLen); + + for (i = 1; i < odd_ints; ++i) { + mont_mulf_noconv(mResult, dSqr, oddPowers[i - 1], + dTmp, dn, MP_DIGITS(modulus), nLen, dn0); + conv_i32_to_d16(oddPowers[i], mResult, nLen); + } + + s_mp_copy(MP_DIGITS(&accum1), mResult, nLen); /* from, to, len */ + + for (expOff = bits_in_exponent - window_bits; expOff >= 0; expOff -= window_bits) { + mp_size smallExp; + MP_CHECKOK( mpl_get_bits(exponent, expOff, window_bits) ); + smallExp = (mp_size)res; + + if (window_bits == 1) { + if (!smallExp) { + SQR; + } else if (smallExp & 1) { + SQR; MUL(0); + } else { + abort(); + } + } else if (window_bits == 4) { + if (!smallExp) { + SQR; SQR; SQR; SQR; + } else if (smallExp & 1) { + SQR; SQR; SQR; SQR; MUL(smallExp/2); + } else if (smallExp & 2) { + SQR; SQR; SQR; MUL(smallExp/4); SQR; + } else if (smallExp & 4) { + SQR; SQR; MUL(smallExp/8); SQR; SQR; + } else if (smallExp & 8) { + SQR; MUL(smallExp/16); SQR; SQR; SQR; + } else { + abort(); + } + } else if (window_bits == 5) { + if (!smallExp) { + SQR; SQR; SQR; SQR; SQR; + } else if (smallExp & 1) { + SQR; SQR; SQR; SQR; SQR; MUL(smallExp/2); + } else if (smallExp & 2) { + SQR; SQR; SQR; SQR; MUL(smallExp/4); SQR; + } else if (smallExp & 4) { + SQR; SQR; SQR; MUL(smallExp/8); SQR; SQR; + } else if (smallExp & 8) { + SQR; SQR; MUL(smallExp/16); SQR; SQR; SQR; + } else if (smallExp & 0x10) { + SQR; MUL(smallExp/32); SQR; SQR; SQR; SQR; + } else { + abort(); + } + } else if (window_bits == 6) { + if (!smallExp) { + SQR; SQR; SQR; SQR; SQR; SQR; + } else if (smallExp & 1) { + SQR; SQR; SQR; SQR; SQR; SQR; MUL(smallExp/2); + } else if (smallExp & 2) { + SQR; SQR; SQR; SQR; SQR; MUL(smallExp/4); SQR; + } else if (smallExp & 4) { + SQR; SQR; SQR; SQR; MUL(smallExp/8); SQR; SQR; + } else if (smallExp & 8) { + SQR; SQR; SQR; MUL(smallExp/16); SQR; SQR; SQR; + } else if (smallExp & 0x10) { + SQR; SQR; MUL(smallExp/32); SQR; SQR; SQR; SQR; + } else if (smallExp & 0x20) { + SQR; MUL(smallExp/64); SQR; SQR; SQR; SQR; SQR; + } else { + abort(); + } + } else { + abort(); + } + } + + s_mp_copy(mResult, MP_DIGITS(&accum1), nLen); /* from, to, len */ + + res = s_mp_redc(&accum1, mmm); + mp_exch(&accum1, result); + +CLEANUP: + mp_clear(&accum1); + if (dBuf) { + if (dSize) + memset(dBuf, 0, dSize); + free(dBuf); + } + + return res; +} +#undef SQR +#undef MUL +#endif + +#define SQR(a,b) \ + MP_CHECKOK( mp_sqr(a, b) );\ + MP_CHECKOK( s_mp_redc(b, mmm) ) + +#if defined(MP_MONT_USE_MP_MUL) +#define MUL(x,a,b) \ + MP_CHECKOK( mp_mul(a, oddPowers + (x), b) ); \ + MP_CHECKOK( s_mp_redc(b, mmm) ) +#else +#define MUL(x,a,b) \ + MP_CHECKOK( s_mp_mul_mont(a, oddPowers + (x), b, mmm) ) +#endif + +#define SWAPPA ptmp = pa1; pa1 = pa2; pa2 = ptmp + +/* Do modular exponentiation using integer multiply code. */ +mp_err mp_exptmod_i(const mp_int * montBase, + const mp_int * exponent, + const mp_int * modulus, + mp_int * result, + mp_mont_modulus *mmm, + int nLen, + mp_size bits_in_exponent, + mp_size window_bits, + mp_size odd_ints) +{ + mp_int *pa1, *pa2, *ptmp; + mp_size i; + mp_err res; + int expOff; + mp_int accum1, accum2, power2, oddPowers[MAX_ODD_INTS]; + + /* power2 = base ** 2; oddPowers[i] = base ** (2*i + 1); */ + /* oddPowers[i] = base ** (2*i + 1); */ + + MP_DIGITS(&accum1) = 0; + MP_DIGITS(&accum2) = 0; + MP_DIGITS(&power2) = 0; + for (i = 0; i < MAX_ODD_INTS; ++i) { + MP_DIGITS(oddPowers + i) = 0; + } + + MP_CHECKOK( mp_init_size(&accum1, 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&accum2, 3 * nLen + 2) ); + + MP_CHECKOK( mp_init_copy(&oddPowers[0], montBase) ); + + mp_init_size(&power2, nLen + 2 * MP_USED(montBase) + 2); + MP_CHECKOK( mp_sqr(montBase, &power2) ); /* power2 = montBase ** 2 */ + MP_CHECKOK( s_mp_redc(&power2, mmm) ); + + for (i = 1; i < odd_ints; ++i) { + mp_init_size(oddPowers + i, nLen + 2 * MP_USED(&power2) + 2); + MP_CHECKOK( mp_mul(oddPowers + (i - 1), &power2, oddPowers + i) ); + MP_CHECKOK( s_mp_redc(oddPowers + i, mmm) ); + } + + /* set accumulator to montgomery residue of 1 */ + mp_set(&accum1, 1); + MP_CHECKOK( s_mp_to_mont(&accum1, mmm, &accum1) ); + pa1 = &accum1; + pa2 = &accum2; + + for (expOff = bits_in_exponent - window_bits; expOff >= 0; expOff -= window_bits) { + mp_size smallExp; + MP_CHECKOK( mpl_get_bits(exponent, expOff, window_bits) ); + smallExp = (mp_size)res; + + if (window_bits == 1) { + if (!smallExp) { + SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 1) { + SQR(pa1,pa2); MUL(0,pa2,pa1); + } else { + abort(); + } + } else if (window_bits == 4) { + if (!smallExp) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + } else if (smallExp & 1) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + MUL(smallExp/2, pa1,pa2); SWAPPA; + } else if (smallExp & 2) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); + MUL(smallExp/4,pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 4) { + SQR(pa1,pa2); SQR(pa2,pa1); MUL(smallExp/8,pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 8) { + SQR(pa1,pa2); MUL(smallExp/16,pa2,pa1); SQR(pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else { + abort(); + } + } else if (window_bits == 5) { + if (!smallExp) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 1) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); MUL(smallExp/2,pa2,pa1); + } else if (smallExp & 2) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + MUL(smallExp/4,pa1,pa2); SQR(pa2,pa1); + } else if (smallExp & 4) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); + MUL(smallExp/8,pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + } else if (smallExp & 8) { + SQR(pa1,pa2); SQR(pa2,pa1); MUL(smallExp/16,pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + } else if (smallExp & 0x10) { + SQR(pa1,pa2); MUL(smallExp/32,pa2,pa1); SQR(pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + } else { + abort(); + } + } else if (window_bits == 6) { + if (!smallExp) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); SQR(pa2,pa1); + } else if (smallExp & 1) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); SQR(pa2,pa1); MUL(smallExp/2,pa1,pa2); SWAPPA; + } else if (smallExp & 2) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); MUL(smallExp/4,pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 4) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + MUL(smallExp/8,pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 8) { + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); + MUL(smallExp/16,pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 0x10) { + SQR(pa1,pa2); SQR(pa2,pa1); MUL(smallExp/32,pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 0x20) { + SQR(pa1,pa2); MUL(smallExp/64,pa2,pa1); SQR(pa1,pa2); + SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SWAPPA; + } else { + abort(); + } + } else { + abort(); + } + } + + res = s_mp_redc(pa1, mmm); + mp_exch(pa1, result); + +CLEANUP: + mp_clear(&accum1); + mp_clear(&accum2); + mp_clear(&power2); + for (i = 0; i < odd_ints; ++i) { + mp_clear(oddPowers + i); + } + return res; +} +#undef SQR +#undef MUL + +#ifdef MP_USING_CACHE_SAFE_MOD_EXP +unsigned int mp_using_cache_safe_exp = 1; +#endif + +mp_err mp_set_safe_modexp(int value) +{ +#ifdef MP_USING_CACHE_SAFE_MOD_EXP + mp_using_cache_safe_exp = value; + return MP_OKAY; +#else + if (value == 0) { + return MP_OKAY; + } + return MP_BADARG; +#endif +} + +#ifdef MP_USING_CACHE_SAFE_MOD_EXP +#define WEAVE_WORD_SIZE 4 + +#ifndef MP_CHAR_STORE_SLOW +/* + * mpi_to_weave takes an array of bignums, a matrix in which each bignum + * occupies all the columns of a row, and transposes it into a matrix in + * which each bignum occupies a column of every row. The first row of the + * input matrix becomes the first column of the output matrix. The n'th + * row of input becomes the n'th column of output. The input data is said + * to be "interleaved" or "woven" into the output matrix. + * + * The array of bignums is left in this woven form. Each time a single + * bignum value is needed, it is recreated by fetching the n'th column, + * forming a single row which is the new bignum. + * + * The purpose of this interleaving is make it impossible to determine which + * of the bignums is being used in any one operation by examining the pattern + * of cache misses. + * + * The weaving function does not transpose the entire input matrix in one call. + * It transposes 4 rows of mp_ints into their respective columns of output. + * + * There are two different implementations of the weaving and unweaving code + * in this file. One uses byte loads and stores. The second uses loads and + * stores of mp_weave_word size values. The weaved forms of these two + * implementations differ. Consequently, each one has its own explanation. + * + * Here is the explanation for the byte-at-a-time implementation. + * + * This implementation treats each mp_int bignum as an array of bytes, + * rather than as an array of mp_digits. It stores those bytes as a + * column of bytes in the output matrix. It doesn't care if the machine + * uses big-endian or little-endian byte ordering within mp_digits. + * The first byte of the mp_digit array becomes the first byte in the output + * column, regardless of whether that byte is the MSB or LSB of the mp_digit. + * + * "bignums" is an array of mp_ints. + * It points to four rows, four mp_ints, a subset of a larger array of mp_ints. + * + * "weaved" is the weaved output matrix. + * The first byte of bignums[0] is stored in weaved[0]. + * + * "nBignums" is the total number of bignums in the array of which "bignums" + * is a part. + * + * "nDigits" is the size in mp_digits of each mp_int in the "bignums" array. + * mp_ints that use less than nDigits digits are logically padded with zeros + * while being stored in the weaved array. + */ +mp_err mpi_to_weave(const mp_int *bignums, + unsigned char *weaved, + mp_size nDigits, /* in each mp_int of input */ + mp_size nBignums) /* in the entire source array */ +{ + mp_size i; + unsigned char * endDest = weaved + (nDigits * nBignums * sizeof(mp_digit)); + + for (i=0; i < WEAVE_WORD_SIZE; i++) { + mp_size used = MP_USED(&bignums[i]); + unsigned char *pSrc = (unsigned char *)MP_DIGITS(&bignums[i]); + unsigned char *endSrc = pSrc + (used * sizeof(mp_digit)); + unsigned char *pDest = weaved + i; + + ARGCHK(MP_SIGN(&bignums[i]) == MP_ZPOS, MP_BADARG); + ARGCHK(used <= nDigits, MP_BADARG); + + for (; pSrc < endSrc; pSrc++) { + *pDest = *pSrc; + pDest += nBignums; + } + while (pDest < endDest) { + *pDest = 0; + pDest += nBignums; + } + } + + return MP_OKAY; +} + +/* Reverse the operation above for one mp_int. + * Reconstruct one mp_int from its column in the weaved array. + * "pSrc" points to the offset into the weave array of the bignum we + * are going to reconstruct. + */ +mp_err weave_to_mpi(mp_int *a, /* output, result */ + const unsigned char *pSrc, /* input, byte matrix */ + mp_size nDigits, /* per mp_int output */ + mp_size nBignums) /* bignums in weaved matrix */ +{ + unsigned char *pDest = (unsigned char *)MP_DIGITS(a); + unsigned char *endDest = pDest + (nDigits * sizeof(mp_digit)); + + MP_SIGN(a) = MP_ZPOS; + MP_USED(a) = nDigits; + + for (; pDest < endDest; pSrc += nBignums, pDest++) { + *pDest = *pSrc; + } + s_mp_clamp(a); + return MP_OKAY; +} + +#else + +/* Need a primitive that we know is 32 bits long... */ +/* this is true on all modern processors we know of today*/ +typedef unsigned int mp_weave_word; + +/* + * on some platforms character stores into memory is very expensive since they + * generate a read/modify/write operation on the bus. On those platforms + * we need to do integer writes to the bus. Because of some unrolled code, + * in this current code the size of mp_weave_word must be four. The code that + * makes this assumption explicity is called out. (on some platforms a write + * of 4 bytes still requires a single read-modify-write operation. + * + * This function is takes the identical parameters as the function above, + * however it lays out the final array differently. Where the previous function + * treats the mpi_int as an byte array, this function treats it as an array of + * mp_digits where each digit is stored in big endian order. + * + * since we need to interleave on a byte by byte basis, we need to collect + * several mpi structures together into a single PRUint32 before we write. We + * also need to make sure the PRUint32 is arranged so that the first value of + * the first array winds up in b[0]. This means construction of that PRUint32 + * is endian specific (even though the layout of the mp_digits in the array + * is always big endian). + * + * The final data is stored as follows : + * + * Our same logical array p array, m is sizeof(mp_digit), + * N is still count and n is now b_size. If we define p[i].digit[j]0 as the + * most significant byte of the word p[i].digit[j], p[i].digit[j]1 as + * the next most significant byte of p[i].digit[j], ... and p[i].digit[j]m-1 + * is the least significant byte. + * Our array would look like: + * p[0].digit[0]0 p[1].digit[0]0 ... p[N-2].digit[0]0 p[N-1].digit[0]0 + * p[0].digit[0]1 p[1].digit[0]1 ... p[N-2].digit[0]1 p[N-1].digit[0]1 + * . . + * p[0].digit[0]m-1 p[1].digit[0]m-1 ... p[N-2].digit[0]m-1 p[N-1].digit[0]m-1 + * p[0].digit[1]0 p[1].digit[1]0 ... p[N-2].digit[1]0 p[N-1].digit[1]0 + * . . + * . . + * p[0].digit[n-1]m-2 p[1].digit[n-1]m-2 ... p[N-2].digit[n-1]m-2 p[N-1].digit[n-1]m-2 + * p[0].digit[n-1]m-1 p[1].digit[n-1]m-1 ... p[N-2].digit[n-1]m-1 p[N-1].digit[n-1]m-1 + * + */ +mp_err mpi_to_weave(const mp_int *a, unsigned char *b, + mp_size b_size, mp_size count) +{ + mp_size i; + mp_digit *digitsa0; + mp_digit *digitsa1; + mp_digit *digitsa2; + mp_digit *digitsa3; + mp_size useda0; + mp_size useda1; + mp_size useda2; + mp_size useda3; + mp_weave_word *weaved = (mp_weave_word *)b; + + count = count/sizeof(mp_weave_word); + + /* this code pretty much depends on this ! */ +#if MP_ARGCHK == 2 + assert(WEAVE_WORD_SIZE == 4); + assert(sizeof(mp_weave_word) == 4); +#endif + + digitsa0 = MP_DIGITS(&a[0]); + digitsa1 = MP_DIGITS(&a[1]); + digitsa2 = MP_DIGITS(&a[2]); + digitsa3 = MP_DIGITS(&a[3]); + useda0 = MP_USED(&a[0]); + useda1 = MP_USED(&a[1]); + useda2 = MP_USED(&a[2]); + useda3 = MP_USED(&a[3]); + + ARGCHK(MP_SIGN(&a[0]) == MP_ZPOS, MP_BADARG); + ARGCHK(MP_SIGN(&a[1]) == MP_ZPOS, MP_BADARG); + ARGCHK(MP_SIGN(&a[2]) == MP_ZPOS, MP_BADARG); + ARGCHK(MP_SIGN(&a[3]) == MP_ZPOS, MP_BADARG); + ARGCHK(useda0 <= b_size, MP_BADARG); + ARGCHK(useda1 <= b_size, MP_BADARG); + ARGCHK(useda2 <= b_size, MP_BADARG); + ARGCHK(useda3 <= b_size, MP_BADARG); + +#define SAFE_FETCH(digit, used, word) ((word) < (used) ? (digit[word]) : 0) + + for (i=0; i < b_size; i++) { + mp_digit d0 = SAFE_FETCH(digitsa0,useda0,i); + mp_digit d1 = SAFE_FETCH(digitsa1,useda1,i); + mp_digit d2 = SAFE_FETCH(digitsa2,useda2,i); + mp_digit d3 = SAFE_FETCH(digitsa3,useda3,i); + register mp_weave_word acc; + +/* + * ONE_STEP takes the MSB of each of our current digits and places that + * byte in the appropriate position for writing to the weaved array. + * On little endian: + * b3 b2 b1 b0 + * On big endian: + * b0 b1 b2 b3 + * When the data is written it would always wind up: + * b[0] = b0 + * b[1] = b1 + * b[2] = b2 + * b[3] = b3 + * + * Once we've written the MSB, we shift the whole digit up left one + * byte, putting the Next Most Significant Byte in the MSB position, + * so we we repeat the next one step that byte will be written. + * NOTE: This code assumes sizeof(mp_weave_word) and MP_WEAVE_WORD_SIZE + * is 4. + */ +#ifdef MP_IS_LITTLE_ENDIAN +#define MPI_WEAVE_ONE_STEP \ + acc = (d0 >> (MP_DIGIT_BIT-8)) & 0x000000ff; d0 <<= 8; /*b0*/ \ + acc |= (d1 >> (MP_DIGIT_BIT-16)) & 0x0000ff00; d1 <<= 8; /*b1*/ \ + acc |= (d2 >> (MP_DIGIT_BIT-24)) & 0x00ff0000; d2 <<= 8; /*b2*/ \ + acc |= (d3 >> (MP_DIGIT_BIT-32)) & 0xff000000; d3 <<= 8; /*b3*/ \ + *weaved = acc; weaved += count; +#else +#define MPI_WEAVE_ONE_STEP \ + acc = (d0 >> (MP_DIGIT_BIT-32)) & 0xff000000; d0 <<= 8; /*b0*/ \ + acc |= (d1 >> (MP_DIGIT_BIT-24)) & 0x00ff0000; d1 <<= 8; /*b1*/ \ + acc |= (d2 >> (MP_DIGIT_BIT-16)) & 0x0000ff00; d2 <<= 8; /*b2*/ \ + acc |= (d3 >> (MP_DIGIT_BIT-8)) & 0x000000ff; d3 <<= 8; /*b3*/ \ + *weaved = acc; weaved += count; +#endif + switch (sizeof(mp_digit)) { + case 32: + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + case 16: + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + case 8: + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + case 4: + MPI_WEAVE_ONE_STEP + MPI_WEAVE_ONE_STEP + case 2: + MPI_WEAVE_ONE_STEP + case 1: + MPI_WEAVE_ONE_STEP + break; + } + } + + return MP_OKAY; +} + +/* reverse the operation above for one entry. + * b points to the offset into the weave array of the power we are + * calculating */ +mp_err weave_to_mpi(mp_int *a, const unsigned char *b, + mp_size b_size, mp_size count) +{ + mp_digit *pb = MP_DIGITS(a); + mp_digit *end = &pb[b_size]; + + MP_SIGN(a) = MP_ZPOS; + MP_USED(a) = b_size; + + for (; pb < end; pb++) { + register mp_digit digit; + + digit = *b << 8; b += count; +#define MPI_UNWEAVE_ONE_STEP digit |= *b; b += count; digit = digit << 8; + switch (sizeof(mp_digit)) { + case 32: + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + case 16: + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + case 8: + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + case 4: + MPI_UNWEAVE_ONE_STEP + MPI_UNWEAVE_ONE_STEP + case 2: + break; + } + digit |= *b; b += count; + + *pb = digit; + } + s_mp_clamp(a); + return MP_OKAY; +} +#endif + + +#define SQR(a,b) \ + MP_CHECKOK( mp_sqr(a, b) );\ + MP_CHECKOK( s_mp_redc(b, mmm) ) + +#if defined(MP_MONT_USE_MP_MUL) +#define MUL_NOWEAVE(x,a,b) \ + MP_CHECKOK( mp_mul(a, x, b) ); \ + MP_CHECKOK( s_mp_redc(b, mmm) ) +#else +#define MUL_NOWEAVE(x,a,b) \ + MP_CHECKOK( s_mp_mul_mont(a, x, b, mmm) ) +#endif + +#define MUL(x,a,b) \ + MP_CHECKOK( weave_to_mpi(&tmp, powers + (x), nLen, num_powers) ); \ + MUL_NOWEAVE(&tmp,a,b) + +#define SWAPPA ptmp = pa1; pa1 = pa2; pa2 = ptmp +#define MP_ALIGN(x,y) ((((ptrdiff_t)(x))+((y)-1))&(((ptrdiff_t)0)-(y))) + +/* Do modular exponentiation using integer multiply code. */ +mp_err mp_exptmod_safe_i(const mp_int * montBase, + const mp_int * exponent, + const mp_int * modulus, + mp_int * result, + mp_mont_modulus *mmm, + int nLen, + mp_size bits_in_exponent, + mp_size window_bits, + mp_size num_powers) +{ + mp_int *pa1, *pa2, *ptmp; + mp_size i; + mp_size first_window; + mp_err res; + int expOff; + mp_int accum1, accum2, accum[WEAVE_WORD_SIZE]; + mp_int tmp; + unsigned char *powersArray; + unsigned char *powers; + + MP_DIGITS(&accum1) = 0; + MP_DIGITS(&accum2) = 0; + MP_DIGITS(&accum[0]) = 0; + MP_DIGITS(&accum[1]) = 0; + MP_DIGITS(&accum[2]) = 0; + MP_DIGITS(&accum[3]) = 0; + MP_DIGITS(&tmp) = 0; + + powersArray = (unsigned char *)malloc(num_powers*(nLen*sizeof(mp_digit)+1)); + if (powersArray == NULL) { + res = MP_MEM; + goto CLEANUP; + } + + /* powers[i] = base ** (i); */ + powers = (unsigned char *)MP_ALIGN(powersArray,num_powers); + + /* grab the first window value. This allows us to preload accumulator1 + * and save a conversion, some squares and a multiple*/ + MP_CHECKOK( mpl_get_bits(exponent, + bits_in_exponent-window_bits, window_bits) ); + first_window = (mp_size)res; + + MP_CHECKOK( mp_init_size(&accum1, 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&accum2, 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&tmp, 3 * nLen + 2) ); + + /* build the first WEAVE_WORD powers inline */ + /* if WEAVE_WORD_SIZE is not 4, this code will have to change */ + if (num_powers > 2) { + MP_CHECKOK( mp_init_size(&accum[0], 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&accum[1], 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&accum[2], 3 * nLen + 2) ); + MP_CHECKOK( mp_init_size(&accum[3], 3 * nLen + 2) ); + mp_set(&accum[0], 1); + MP_CHECKOK( s_mp_to_mont(&accum[0], mmm, &accum[0]) ); + MP_CHECKOK( mp_copy(montBase, &accum[1]) ); + SQR(montBase, &accum[2]); + MUL_NOWEAVE(montBase, &accum[2], &accum[3]); + MP_CHECKOK( mpi_to_weave(accum, powers, nLen, num_powers) ); + if (first_window < 4) { + MP_CHECKOK( mp_copy(&accum[first_window], &accum1) ); + first_window = num_powers; + } + } else { + if (first_window == 0) { + mp_set(&accum1, 1); + MP_CHECKOK( s_mp_to_mont(&accum1, mmm, &accum1) ); + } else { + /* assert first_window == 1? */ + MP_CHECKOK( mp_copy(montBase, &accum1) ); + } + } + + /* + * calculate all the powers in the powers array. + * this adds 2**(k-1)-2 square operations over just calculating the + * odd powers where k is the window size in the two other mp_modexpt + * implementations in this file. We will get some of that + * back by not needing the first 'k' squares and one multiply for the + * first window */ + for (i = WEAVE_WORD_SIZE; i < num_powers; i++) { + int acc_index = i & (WEAVE_WORD_SIZE-1); /* i % WEAVE_WORD_SIZE */ + if ( i & 1 ) { + MUL_NOWEAVE(montBase, &accum[acc_index-1] , &accum[acc_index]); + /* we've filled the array do our 'per array' processing */ + if (acc_index == (WEAVE_WORD_SIZE-1)) { + MP_CHECKOK( mpi_to_weave(accum, powers + i - (WEAVE_WORD_SIZE-1), + nLen, num_powers) ); + + if (first_window <= i) { + MP_CHECKOK( mp_copy(&accum[first_window & (WEAVE_WORD_SIZE-1)], + &accum1) ); + first_window = num_powers; + } + } + } else { + /* up to 8 we can find 2^i-1 in the accum array, but at 8 we our source + * and target are the same so we need to copy.. After that, the + * value is overwritten, so we need to fetch it from the stored + * weave array */ + if (i > 2* WEAVE_WORD_SIZE) { + MP_CHECKOK(weave_to_mpi(&accum2, powers+i/2, nLen, num_powers)); + SQR(&accum2, &accum[acc_index]); + } else { + int half_power_index = (i/2) & (WEAVE_WORD_SIZE-1); + if (half_power_index == acc_index) { + /* copy is cheaper than weave_to_mpi */ + MP_CHECKOK(mp_copy(&accum[half_power_index], &accum2)); + SQR(&accum2,&accum[acc_index]); + } else { + SQR(&accum[half_power_index],&accum[acc_index]); + } + } + } + } + /* if the accum1 isn't set, Then there is something wrong with our logic + * above and is an internal programming error. + */ +#if MP_ARGCHK == 2 + assert(MP_USED(&accum1) != 0); +#endif + + /* set accumulator to montgomery residue of 1 */ + pa1 = &accum1; + pa2 = &accum2; + + for (expOff = bits_in_exponent - window_bits*2; expOff >= 0; expOff -= window_bits) { + mp_size smallExp; + MP_CHECKOK( mpl_get_bits(exponent, expOff, window_bits) ); + smallExp = (mp_size)res; + + /* handle unroll the loops */ + switch (window_bits) { + case 1: + if (!smallExp) { + SQR(pa1,pa2); SWAPPA; + } else if (smallExp & 1) { + SQR(pa1,pa2); MUL_NOWEAVE(montBase,pa2,pa1); + } else { + abort(); + } + break; + case 6: + SQR(pa1,pa2); SQR(pa2,pa1); + /* fall through */ + case 4: + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + MUL(smallExp, pa1,pa2); SWAPPA; + break; + case 5: + SQR(pa1,pa2); SQR(pa2,pa1); SQR(pa1,pa2); SQR(pa2,pa1); + SQR(pa1,pa2); MUL(smallExp,pa2,pa1); + break; + default: + abort(); /* could do a loop? */ + } + } + + res = s_mp_redc(pa1, mmm); + mp_exch(pa1, result); + +CLEANUP: + mp_clear(&accum1); + mp_clear(&accum2); + mp_clear(&accum[0]); + mp_clear(&accum[1]); + mp_clear(&accum[2]); + mp_clear(&accum[3]); + mp_clear(&tmp); + /* PORT_Memset(powers,0,num_powers*nLen*sizeof(mp_digit)); */ + free(powersArray); + return res; +} +#undef SQR +#undef MUL +#endif + +mp_err mp_exptmod(const mp_int *inBase, const mp_int *exponent, + const mp_int *modulus, mp_int *result) +{ + const mp_int *base; + mp_size bits_in_exponent, i, window_bits, odd_ints; + mp_err res; + int nLen; + mp_int montBase, goodBase; + mp_mont_modulus mmm; +#ifdef MP_USING_CACHE_SAFE_MOD_EXP + static unsigned int max_window_bits; +#endif + + /* function for computing n0prime only works if n0 is odd */ + if (!mp_isodd(modulus)) + return s_mp_exptmod(inBase, exponent, modulus, result); + + MP_DIGITS(&montBase) = 0; + MP_DIGITS(&goodBase) = 0; + + if (mp_cmp(inBase, modulus) < 0) { + base = inBase; + } else { + MP_CHECKOK( mp_init(&goodBase) ); + base = &goodBase; + MP_CHECKOK( mp_mod(inBase, modulus, &goodBase) ); + } + + nLen = MP_USED(modulus); + MP_CHECKOK( mp_init_size(&montBase, 2 * nLen + 2) ); + + mmm.N = *modulus; /* a copy of the mp_int struct */ + + /* compute n0', given n0, n0' = -(n0 ** -1) mod MP_RADIX + ** where n0 = least significant mp_digit of N, the modulus. + */ + mmm.n0prime = 0 - s_mp_invmod_radix( MP_DIGIT(modulus, 0) ); + + MP_CHECKOK( s_mp_to_mont(base, &mmm, &montBase) ); + + bits_in_exponent = mpl_significant_bits(exponent); +#ifdef MP_USING_CACHE_SAFE_MOD_EXP + if (mp_using_cache_safe_exp) { + if (bits_in_exponent > 780) + window_bits = 6; + else if (bits_in_exponent > 256) + window_bits = 5; + else if (bits_in_exponent > 20) + window_bits = 4; + /* RSA public key exponents are typically under 20 bits (common values + * are: 3, 17, 65537) and a 4-bit window is inefficient + */ + else + window_bits = 1; + } else +#endif + if (bits_in_exponent > 480) + window_bits = 6; + else if (bits_in_exponent > 160) + window_bits = 5; + else if (bits_in_exponent > 20) + window_bits = 4; + /* RSA public key exponents are typically under 20 bits (common values + * are: 3, 17, 65537) and a 4-bit window is inefficient + */ + else + window_bits = 1; + +#ifdef MP_USING_CACHE_SAFE_MOD_EXP + /* + * clamp the window size based on + * the cache line size. + */ + if (!max_window_bits) { + unsigned long cache_size = s_mpi_getProcessorLineSize(); + /* processor has no cache, use 'fast' code always */ + if (cache_size == 0) { + mp_using_cache_safe_exp = 0; + } + if ((cache_size == 0) || (cache_size >= 64)) { + max_window_bits = 6; + } else if (cache_size >= 32) { + max_window_bits = 5; + } else if (cache_size >= 16) { + max_window_bits = 4; + } else max_window_bits = 1; /* should this be an assert? */ + } + + /* clamp the window size down before we caclulate bits_in_exponent */ + if (mp_using_cache_safe_exp) { + if (window_bits > max_window_bits) { + window_bits = max_window_bits; + } + } +#endif + + odd_ints = 1 << (window_bits - 1); + i = bits_in_exponent % window_bits; + if (i != 0) { + bits_in_exponent += window_bits - i; + } + +#ifdef MP_USING_MONT_MULF + if (mp_using_mont_mulf) { + MP_CHECKOK( s_mp_pad(&montBase, nLen) ); + res = mp_exptmod_f(&montBase, exponent, modulus, result, &mmm, nLen, + bits_in_exponent, window_bits, odd_ints); + } else +#endif +#ifdef MP_USING_CACHE_SAFE_MOD_EXP + if (mp_using_cache_safe_exp) { + res = mp_exptmod_safe_i(&montBase, exponent, modulus, result, &mmm, nLen, + bits_in_exponent, window_bits, 1 << window_bits); + } else +#endif + res = mp_exptmod_i(&montBase, exponent, modulus, result, &mmm, nLen, + bits_in_exponent, window_bits, odd_ints); + +CLEANUP: + mp_clear(&montBase); + mp_clear(&goodBase); + /* Don't mp_clear mmm.N because it is merely a copy of modulus. + ** Just zap it. + */ + memset(&mmm, 0, sizeof mmm); + return res; +}