summaryrefslogtreecommitdiffstats
path: root/security/nss/lib/freebl/mpi/montmulf.h
blob: 69bed4acb142b842ff4cd30540dde6ee74a4bbd7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
/* 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/. */

/*  The functions that are to be called from outside of the .s file have the
 *  following interfaces and array size requirements:
 */

void conv_i32_to_d32(double *d32, unsigned int *i32, int len);

/*  Converts an array of int's to an array of doubles, so that each double
 *  corresponds to an int.  len is the number of items converted.
 *  Does not allocate the output array.
 *  The pointers d32 and i32 should point to arrays of size at least  len
 *  (doubles and unsigned ints, respectively)
 */

void conv_i32_to_d16(double *d16, unsigned int *i32, int len);

/*  Converts an array of int's to an array of doubles so that each element
 *  of the int array is converted to a pair of doubles, the first one
 *  corresponding to the lower (least significant) 16 bits of the int and
 *  the second one corresponding to the upper (most significant) 16 bits of
 *  the 32-bit int. len is the number of ints converted.
 *  Does not allocate the output array.
 *  The pointer d16 should point to an array of doubles of size at least
 *  2*len and i32 should point an array of ints of size at least  len
 */

void conv_i32_to_d32_and_d16(double *d32, double *d16,
                             unsigned int *i32, int len);

/*  Does the above two conversions together, it is much faster than doing
 *  both of those in succession
 */

void mont_mulf_noconv(unsigned int *result,
                      double *dm1, double *dm2, double *dt,
                      double *dn, unsigned int *nint,
                      int nlen, double dn0);

/*  Does the Montgomery multiplication of the numbers stored in the arrays
 *  pointed to by dm1 and dm2, writing the result to the array pointed to by
 *  result. It uses the array pointed to by dt as a temporary work area.
 *  nint should point to the modulus in the array-of-integers representation,
 *  dn should point to its array-of-doubles as obtained as a result of the
 *  function call   conv_i32_to_d32(dn, nint, nlen);
 *  nlen is the length of the array containing the modulus.
 *  The representation used for dm1 is the one that is a result of the function
 *  call   conv_i32_to_d32(dm1, m1, nlen), the representation for dm2 is the
 *  result of the function call   conv_i32_to_d16(dm2, m2, nlen).
 *  Note that m1 and m2 should both be of length nlen, so they should be
 *  padded with 0's if necessary before the conversion. The result comes in
 *  this form (int representation, padded with 0's).
 *  dn0 is the value of the 16 least significant bits of n0'.
 *  The function does not allocate memory for any of the arrays, so the
 *  pointers should point to arrays with the following minimal sizes:
 *  result - nlen+1
 *  dm1    - nlen
 *  dm2    - 2*nlen+1  ( the +1 is necessary for technical reasons )
 *  dt     - 4*nlen+2
 *  dn     - nlen
 *  nint   - nlen
 *  No two arrays should point to overlapping areas of memory.
 */