diff options
Diffstat (limited to 'security/nss/lib/freebl/mpi/mplogic.c')
-rw-r--r-- | security/nss/lib/freebl/mpi/mplogic.c | 433 |
1 files changed, 0 insertions, 433 deletions
diff --git a/security/nss/lib/freebl/mpi/mplogic.c b/security/nss/lib/freebl/mpi/mplogic.c deleted file mode 100644 index e2e651dd3..000000000 --- a/security/nss/lib/freebl/mpi/mplogic.c +++ /dev/null @@ -1,433 +0,0 @@ -/* - * mplogic.c - * - * Bitwise logical operations on MPI values - * - * 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/. */ -/* $Id$ */ - -#include "mpi-priv.h" -#include "mplogic.h" - -/* {{{ Lookup table for population count */ - -static unsigned char bitc[] = { - 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, - 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 -}; - -/* }}} */ - -/*------------------------------------------------------------------------*/ -/* - mpl_not(a, b) - compute b = ~a - mpl_and(a, b, c) - compute c = a & b - mpl_or(a, b, c) - compute c = a | b - mpl_xor(a, b, c) - compute c = a ^ b - */ - -/* {{{ mpl_not(a, b) */ - -mp_err mpl_not(mp_int *a, mp_int *b) -{ - mp_err res; - unsigned int ix; - - ARGCHK(a != NULL && b != NULL, MP_BADARG); - - if((res = mp_copy(a, b)) != MP_OKAY) - return res; - - /* This relies on the fact that the digit type is unsigned */ - for(ix = 0; ix < USED(b); ix++) - DIGIT(b, ix) = ~DIGIT(b, ix); - - s_mp_clamp(b); - - return MP_OKAY; - -} /* end mpl_not() */ - -/* }}} */ - -/* {{{ mpl_and(a, b, c) */ - -mp_err mpl_and(mp_int *a, mp_int *b, mp_int *c) -{ - mp_int *which, *other; - mp_err res; - unsigned int ix; - - ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG); - - if(USED(a) <= USED(b)) { - which = a; - other = b; - } else { - which = b; - other = a; - } - - if((res = mp_copy(which, c)) != MP_OKAY) - return res; - - for(ix = 0; ix < USED(which); ix++) - DIGIT(c, ix) &= DIGIT(other, ix); - - s_mp_clamp(c); - - return MP_OKAY; - -} /* end mpl_and() */ - -/* }}} */ - -/* {{{ mpl_or(a, b, c) */ - -mp_err mpl_or(mp_int *a, mp_int *b, mp_int *c) -{ - mp_int *which, *other; - mp_err res; - unsigned int ix; - - ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG); - - if(USED(a) >= USED(b)) { - which = a; - other = b; - } else { - which = b; - other = a; - } - - if((res = mp_copy(which, c)) != MP_OKAY) - return res; - - for(ix = 0; ix < USED(which); ix++) - DIGIT(c, ix) |= DIGIT(other, ix); - - return MP_OKAY; - -} /* end mpl_or() */ - -/* }}} */ - -/* {{{ mpl_xor(a, b, c) */ - -mp_err mpl_xor(mp_int *a, mp_int *b, mp_int *c) -{ - mp_int *which, *other; - mp_err res; - unsigned int ix; - - ARGCHK(a != NULL && b != NULL && c != NULL, MP_BADARG); - - if(USED(a) >= USED(b)) { - which = a; - other = b; - } else { - which = b; - other = a; - } - - if((res = mp_copy(which, c)) != MP_OKAY) - return res; - - for(ix = 0; ix < USED(which); ix++) - DIGIT(c, ix) ^= DIGIT(other, ix); - - s_mp_clamp(c); - - return MP_OKAY; - -} /* end mpl_xor() */ - -/* }}} */ - -/*------------------------------------------------------------------------*/ -/* - mpl_rsh(a, b, d) - b = a >> d - mpl_lsh(a, b, d) - b = a << d - */ - -/* {{{ mpl_rsh(a, b, d) */ - -mp_err mpl_rsh(const mp_int *a, mp_int *b, mp_digit d) -{ - mp_err res; - - ARGCHK(a != NULL && b != NULL, MP_BADARG); - - if((res = mp_copy(a, b)) != MP_OKAY) - return res; - - s_mp_div_2d(b, d); - - return MP_OKAY; - -} /* end mpl_rsh() */ - -/* }}} */ - -/* {{{ mpl_lsh(a, b, d) */ - -mp_err mpl_lsh(const mp_int *a, mp_int *b, mp_digit d) -{ - mp_err res; - - ARGCHK(a != NULL && b != NULL, MP_BADARG); - - if((res = mp_copy(a, b)) != MP_OKAY) - return res; - - return s_mp_mul_2d(b, d); - -} /* end mpl_lsh() */ - -/* }}} */ - -/*------------------------------------------------------------------------*/ -/* - mpl_num_set(a, num) - - Count the number of set bits in the binary representation of a. - Returns MP_OKAY and sets 'num' to be the number of such bits, if - possible. If num is NULL, the result is thrown away, but it is - not considered an error. - - mpl_num_clear() does basically the same thing for clear bits. - */ - -/* {{{ mpl_num_set(a, num) */ - -mp_err mpl_num_set(mp_int *a, int *num) -{ - unsigned int ix; - int db, nset = 0; - mp_digit cur; - unsigned char reg; - - ARGCHK(a != NULL, MP_BADARG); - - for(ix = 0; ix < USED(a); ix++) { - cur = DIGIT(a, ix); - - for(db = 0; db < sizeof(mp_digit); db++) { - reg = (unsigned char)(cur >> (CHAR_BIT * db)); - - nset += bitc[reg]; - } - } - - if(num) - *num = nset; - - return MP_OKAY; - -} /* end mpl_num_set() */ - -/* }}} */ - -/* {{{ mpl_num_clear(a, num) */ - -mp_err mpl_num_clear(mp_int *a, int *num) -{ - unsigned int ix; - int db, nset = 0; - mp_digit cur; - unsigned char reg; - - ARGCHK(a != NULL, MP_BADARG); - - for(ix = 0; ix < USED(a); ix++) { - cur = DIGIT(a, ix); - - for(db = 0; db < sizeof(mp_digit); db++) { - reg = (unsigned char)(cur >> (CHAR_BIT * db)); - - nset += bitc[UCHAR_MAX - reg]; - } - } - - if(num) - *num = nset; - - return MP_OKAY; - - -} /* end mpl_num_clear() */ - -/* }}} */ - -/*------------------------------------------------------------------------*/ -/* - mpl_parity(a) - - Determines the bitwise parity of the value given. Returns MP_EVEN - if an even number of digits are set, MP_ODD if an odd number are - set. - */ - -/* {{{ mpl_parity(a) */ - -mp_err mpl_parity(mp_int *a) -{ - unsigned int ix; - int par = 0; - mp_digit cur; - - ARGCHK(a != NULL, MP_BADARG); - - for(ix = 0; ix < USED(a); ix++) { - int shft = (sizeof(mp_digit) * CHAR_BIT) / 2; - - cur = DIGIT(a, ix); - - /* Compute parity for current digit */ - while(shft != 0) { - cur ^= (cur >> shft); - shft >>= 1; - } - cur &= 1; - - /* XOR with running parity so far */ - par ^= cur; - } - - if(par) - return MP_ODD; - else - return MP_EVEN; - -} /* end mpl_parity() */ - -/* }}} */ - -/* - mpl_set_bit - - Returns MP_OKAY or some error code. - Grows a if needed to set a bit to 1. - */ -mp_err mpl_set_bit(mp_int *a, mp_size bitNum, mp_size value) -{ - mp_size ix; - mp_err rv; - mp_digit mask; - - ARGCHK(a != NULL, MP_BADARG); - - ix = bitNum / MP_DIGIT_BIT; - if (ix + 1 > MP_USED(a)) { - rv = s_mp_pad(a, ix + 1); - if (rv != MP_OKAY) - return rv; - } - - bitNum = bitNum % MP_DIGIT_BIT; - mask = (mp_digit)1 << bitNum; - if (value) - MP_DIGIT(a,ix) |= mask; - else - MP_DIGIT(a,ix) &= ~mask; - s_mp_clamp(a); - return MP_OKAY; -} - -/* - mpl_get_bit - - returns 0 or 1 or some (negative) error code. - */ -mp_err mpl_get_bit(const mp_int *a, mp_size bitNum) -{ - mp_size bit, ix; - mp_err rv; - - ARGCHK(a != NULL, MP_BADARG); - - ix = bitNum / MP_DIGIT_BIT; - ARGCHK(ix <= MP_USED(a) - 1, MP_RANGE); - - bit = bitNum % MP_DIGIT_BIT; - rv = (mp_err)(MP_DIGIT(a, ix) >> bit) & 1; - return rv; -} - -/* - mpl_get_bits - - Extracts numBits bits from a, where the least significant extracted bit - is bit lsbNum. Returns a negative value if error occurs. - - Because sign bit is used to indicate error, maximum number of bits to - be returned is the lesser of (a) the number of bits in an mp_digit, or - (b) one less than the number of bits in an mp_err. - - lsbNum + numbits can be greater than the number of significant bits in - integer a, as long as bit lsbNum is in the high order digit of a. - */ -mp_err mpl_get_bits(const mp_int *a, mp_size lsbNum, mp_size numBits) -{ - mp_size rshift = (lsbNum % MP_DIGIT_BIT); - mp_size lsWndx = (lsbNum / MP_DIGIT_BIT); - mp_digit * digit = MP_DIGITS(a) + lsWndx; - mp_digit mask = ((1 << numBits) - 1); - - ARGCHK(numBits < CHAR_BIT * sizeof mask, MP_BADARG); - ARGCHK(MP_HOWMANY(lsbNum, MP_DIGIT_BIT) <= MP_USED(a), MP_RANGE); - - if ((numBits + lsbNum % MP_DIGIT_BIT <= MP_DIGIT_BIT) || - (lsWndx + 1 >= MP_USED(a))) { - mask &= (digit[0] >> rshift); - } else { - mask &= ((digit[0] >> rshift) | (digit[1] << (MP_DIGIT_BIT - rshift))); - } - return (mp_err)mask; -} - -/* - mpl_significant_bits - returns number of significnant bits in abs(a). - returns 1 if value is zero. - */ -mp_err mpl_significant_bits(const mp_int *a) -{ - mp_err bits = 0; - int ix; - - ARGCHK(a != NULL, MP_BADARG); - - ix = MP_USED(a); - for (ix = MP_USED(a); ix > 0; ) { - mp_digit d; - d = MP_DIGIT(a, --ix); - if (d) { - while (d) { - ++bits; - d >>= 1; - } - break; - } - } - bits += ix * MP_DIGIT_BIT; - if (!bits) - bits = 1; - return bits; -} - -/*------------------------------------------------------------------------*/ -/* HERE THERE BE DRAGONS */ |