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authorDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-08-31 07:05:16 -0400
committerDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-11-09 04:45:22 -0500
commitcdec9cb5167ab1113ba9c58e395f664d9d3f9acb (patch)
tree7d9a4ab3e86b937354d0151a24d412ea8d56ad43 /lib
parent1ea6b8f48918282bdca0b32a34095504ee65bab5 (diff)
crypto: GnuPG based MPI lib - source files (part 1)
Adds the multi-precision-integer maths library which was originally taken from GnuPG and ported to the kernel by (among others) David Howells. This version is taken from Fedora kernel 2.6.32-71.14.1.el6. The difference is that checkpatch reported errors and warnings have been fixed. This library is used to implemenet RSA digital signature verification used in IMA/EVM integrity protection subsystem. Due to patch size limitation, the patch is divided into 4 parts. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Diffstat (limited to 'lib')
-rw-r--r--lib/mpi/generic_mpih-add1.c61
-rw-r--r--lib/mpi/generic_mpih-lshift.c63
-rw-r--r--lib/mpi/generic_mpih-mul1.c57
-rw-r--r--lib/mpi/generic_mpih-mul2.c60
-rw-r--r--lib/mpi/generic_mpih-mul3.c61
-rw-r--r--lib/mpi/generic_mpih-rshift.c63
-rw-r--r--lib/mpi/generic_mpih-sub1.c60
-rw-r--r--lib/mpi/mpi-bit.c236
-rw-r--r--lib/mpi/mpi-pow.c323
-rw-r--r--lib/mpi/mpicoder.c365
-rw-r--r--lib/mpi/mpih-cmp.c56
-rw-r--r--lib/mpi/mpih-div.c541
-rw-r--r--lib/mpi/mpih-mul.c527
-rw-r--r--lib/mpi/mpiutil.c208
14 files changed, 2681 insertions, 0 deletions
diff --git a/lib/mpi/generic_mpih-add1.c b/lib/mpi/generic_mpih-add1.c
new file mode 100644
index 000000000000..c94c7dd344b3
--- /dev/null
+++ b/lib/mpi/generic_mpih-add1.c
@@ -0,0 +1,61 @@
1/* mpihelp-add_1.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1997, 1998,
3 * 2000 Free Software Foundation, Inc.
4 *
5 * This file is part of GnuPG.
6 *
7 * GnuPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GnuPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#include "mpi-internal.h"
31#include "longlong.h"
32
33mpi_limb_t
34mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
35 mpi_ptr_t s2_ptr, mpi_size_t size)
36{
37 mpi_limb_t x, y, cy;
38 mpi_size_t j;
39
40 /* The loop counter and index J goes from -SIZE to -1. This way
41 the loop becomes faster. */
42 j = -size;
43
44 /* Offset the base pointers to compensate for the negative indices. */
45 s1_ptr -= j;
46 s2_ptr -= j;
47 res_ptr -= j;
48
49 cy = 0;
50 do {
51 y = s2_ptr[j];
52 x = s1_ptr[j];
53 y += cy; /* add previous carry to one addend */
54 cy = y < cy; /* get out carry from that addition */
55 y += x; /* add other addend */
56 cy += y < x; /* get out carry from that add, combine */
57 res_ptr[j] = y;
58 } while (++j);
59
60 return cy;
61}
diff --git a/lib/mpi/generic_mpih-lshift.c b/lib/mpi/generic_mpih-lshift.c
new file mode 100644
index 000000000000..86318927231a
--- /dev/null
+++ b/lib/mpi/generic_mpih-lshift.c
@@ -0,0 +1,63 @@
1/* mpihelp-lshift.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1998, 2001 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include "mpi-internal.h"
30
31/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
32 * and store the USIZE least significant digits of the result at WP.
33 * Return the bits shifted out from the most significant digit.
34 *
35 * Argument constraints:
36 * 1. 0 < CNT < BITS_PER_MP_LIMB
37 * 2. If the result is to be written over the input, WP must be >= UP.
38 */
39
40mpi_limb_t
41mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned int cnt)
42{
43 mpi_limb_t high_limb, low_limb;
44 unsigned sh_1, sh_2;
45 mpi_size_t i;
46 mpi_limb_t retval;
47
48 sh_1 = cnt;
49 wp += 1;
50 sh_2 = BITS_PER_MPI_LIMB - sh_1;
51 i = usize - 1;
52 low_limb = up[i];
53 retval = low_limb >> sh_2;
54 high_limb = low_limb;
55 while (--i >= 0) {
56 low_limb = up[i];
57 wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
58 high_limb = low_limb;
59 }
60 wp[i] = high_limb << sh_1;
61
62 return retval;
63}
diff --git a/lib/mpi/generic_mpih-mul1.c b/lib/mpi/generic_mpih-mul1.c
new file mode 100644
index 000000000000..1668dfd9092c
--- /dev/null
+++ b/lib/mpi/generic_mpih-mul1.c
@@ -0,0 +1,57 @@
1/* mpihelp-mul_1.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include "mpi-internal.h"
30#include "longlong.h"
31
32mpi_limb_t
33mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
34 mpi_limb_t s2_limb)
35{
36 mpi_limb_t cy_limb;
37 mpi_size_t j;
38 mpi_limb_t prod_high, prod_low;
39
40 /* The loop counter and index J goes from -S1_SIZE to -1. This way
41 * the loop becomes faster. */
42 j = -s1_size;
43
44 /* Offset the base pointers to compensate for the negative indices. */
45 s1_ptr -= j;
46 res_ptr -= j;
47
48 cy_limb = 0;
49 do {
50 umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
51 prod_low += cy_limb;
52 cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
53 res_ptr[j] = prod_low;
54 } while (++j);
55
56 return cy_limb;
57}
diff --git a/lib/mpi/generic_mpih-mul2.c b/lib/mpi/generic_mpih-mul2.c
new file mode 100644
index 000000000000..8a7b29ee1740
--- /dev/null
+++ b/lib/mpi/generic_mpih-mul2.c
@@ -0,0 +1,60 @@
1/* mpihelp-mul_2.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include "mpi-internal.h"
30#include "longlong.h"
31
32mpi_limb_t
33mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
34 mpi_size_t s1_size, mpi_limb_t s2_limb)
35{
36 mpi_limb_t cy_limb;
37 mpi_size_t j;
38 mpi_limb_t prod_high, prod_low;
39 mpi_limb_t x;
40
41 /* The loop counter and index J goes from -SIZE to -1. This way
42 * the loop becomes faster. */
43 j = -s1_size;
44 res_ptr -= j;
45 s1_ptr -= j;
46
47 cy_limb = 0;
48 do {
49 umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
50
51 prod_low += cy_limb;
52 cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
53
54 x = res_ptr[j];
55 prod_low = x + prod_low;
56 cy_limb += prod_low < x ? 1 : 0;
57 res_ptr[j] = prod_low;
58 } while (++j);
59 return cy_limb;
60}
diff --git a/lib/mpi/generic_mpih-mul3.c b/lib/mpi/generic_mpih-mul3.c
new file mode 100644
index 000000000000..f96df327be63
--- /dev/null
+++ b/lib/mpi/generic_mpih-mul3.c
@@ -0,0 +1,61 @@
1/* mpihelp-mul_3.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include "mpi-internal.h"
30#include "longlong.h"
31
32mpi_limb_t
33mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
34 mpi_size_t s1_size, mpi_limb_t s2_limb)
35{
36 mpi_limb_t cy_limb;
37 mpi_size_t j;
38 mpi_limb_t prod_high, prod_low;
39 mpi_limb_t x;
40
41 /* The loop counter and index J goes from -SIZE to -1. This way
42 * the loop becomes faster. */
43 j = -s1_size;
44 res_ptr -= j;
45 s1_ptr -= j;
46
47 cy_limb = 0;
48 do {
49 umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
50
51 prod_low += cy_limb;
52 cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
53
54 x = res_ptr[j];
55 prod_low = x - prod_low;
56 cy_limb += prod_low > x ? 1 : 0;
57 res_ptr[j] = prod_low;
58 } while (++j);
59
60 return cy_limb;
61}
diff --git a/lib/mpi/generic_mpih-rshift.c b/lib/mpi/generic_mpih-rshift.c
new file mode 100644
index 000000000000..ffa328818ca6
--- /dev/null
+++ b/lib/mpi/generic_mpih-rshift.c
@@ -0,0 +1,63 @@
1/* mpih-rshift.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1998, 1999,
3 * 2000, 2001 Free Software Foundation, Inc.
4 *
5 * This file is part of GNUPG
6 *
7 * GNUPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GNUPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#include "mpi-internal.h"
31
32/* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right
33 * and store the USIZE least significant limbs of the result at WP.
34 * The bits shifted out to the right are returned.
35 *
36 * Argument constraints:
37 * 1. 0 < CNT < BITS_PER_MP_LIMB
38 * 2. If the result is to be written over the input, WP must be <= UP.
39 */
40
41mpi_limb_t
42mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt)
43{
44 mpi_limb_t high_limb, low_limb;
45 unsigned sh_1, sh_2;
46 mpi_size_t i;
47 mpi_limb_t retval;
48
49 sh_1 = cnt;
50 wp -= 1;
51 sh_2 = BITS_PER_MPI_LIMB - sh_1;
52 high_limb = up[0];
53 retval = high_limb << sh_2;
54 low_limb = high_limb;
55 for (i = 1; i < usize; i++) {
56 high_limb = up[i];
57 wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
58 low_limb = high_limb;
59 }
60 wp[i] = low_limb >> sh_1;
61
62 return retval;
63}
diff --git a/lib/mpi/generic_mpih-sub1.c b/lib/mpi/generic_mpih-sub1.c
new file mode 100644
index 000000000000..5d98ab7d6853
--- /dev/null
+++ b/lib/mpi/generic_mpih-sub1.c
@@ -0,0 +1,60 @@
1/* mpihelp-add_2.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include "mpi-internal.h"
30#include "longlong.h"
31
32mpi_limb_t
33mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
34 mpi_ptr_t s2_ptr, mpi_size_t size)
35{
36 mpi_limb_t x, y, cy;
37 mpi_size_t j;
38
39 /* The loop counter and index J goes from -SIZE to -1. This way
40 the loop becomes faster. */
41 j = -size;
42
43 /* Offset the base pointers to compensate for the negative indices. */
44 s1_ptr -= j;
45 s2_ptr -= j;
46 res_ptr -= j;
47
48 cy = 0;
49 do {
50 y = s2_ptr[j];
51 x = s1_ptr[j];
52 y += cy; /* add previous carry to subtrahend */
53 cy = y < cy; /* get out carry from that addition */
54 y = x - y; /* main subtract */
55 cy += y > x; /* get out carry from the subtract, combine */
56 res_ptr[j] = y;
57 } while (++j);
58
59 return cy;
60}
diff --git a/lib/mpi/mpi-bit.c b/lib/mpi/mpi-bit.c
new file mode 100644
index 000000000000..854c9c6da025
--- /dev/null
+++ b/lib/mpi/mpi-bit.c
@@ -0,0 +1,236 @@
1/* mpi-bit.c - MPI bit level fucntions
2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 */
20
21#include "mpi-internal.h"
22#include "longlong.h"
23
24const unsigned char __clz_tab[] = {
25 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
26 5, 5, 5, 5, 5, 5, 5, 5,
27 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
28 6, 6, 6, 6, 6, 6, 6, 6,
29 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
30 7, 7, 7, 7, 7, 7, 7, 7,
31 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
32 7, 7, 7, 7, 7, 7, 7, 7,
33 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
34 8, 8, 8, 8, 8, 8, 8, 8,
35 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
36 8, 8, 8, 8, 8, 8, 8, 8,
37 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
38 8, 8, 8, 8, 8, 8, 8, 8,
39 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
40 8, 8, 8, 8, 8, 8, 8, 8,
41};
42
43#define A_LIMB_1 ((mpi_limb_t) 1)
44
45/****************
46 * Sometimes we have MSL (most significant limbs) which are 0;
47 * this is for some reasons not good, so this function removes them.
48 */
49void mpi_normalize(MPI a)
50{
51 for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--)
52 ;
53}
54
55/****************
56 * Return the number of bits in A.
57 */
58unsigned mpi_get_nbits(MPI a)
59{
60 unsigned n;
61
62 mpi_normalize(a);
63
64 if (a->nlimbs) {
65 mpi_limb_t alimb = a->d[a->nlimbs - 1];
66 if (alimb)
67 count_leading_zeros(n, alimb);
68 else
69 n = BITS_PER_MPI_LIMB;
70 n = BITS_PER_MPI_LIMB - n + (a->nlimbs - 1) * BITS_PER_MPI_LIMB;
71 } else
72 n = 0;
73 return n;
74}
75EXPORT_SYMBOL_GPL(mpi_get_nbits);
76
77/****************
78 * Test whether bit N is set.
79 */
80int mpi_test_bit(MPI a, unsigned n)
81{
82 unsigned limbno, bitno;
83 mpi_limb_t limb;
84
85 limbno = n / BITS_PER_MPI_LIMB;
86 bitno = n % BITS_PER_MPI_LIMB;
87
88 if (limbno >= a->nlimbs)
89 return 0; /* too far left: this is a 0 */
90 limb = a->d[limbno];
91 return (limb & (A_LIMB_1 << bitno)) ? 1 : 0;
92}
93
94/****************
95 * Set bit N of A.
96 */
97int mpi_set_bit(MPI a, unsigned n)
98{
99 unsigned limbno, bitno;
100
101 limbno = n / BITS_PER_MPI_LIMB;
102 bitno = n % BITS_PER_MPI_LIMB;
103
104 if (limbno >= a->nlimbs) { /* resize */
105 if (a->alloced >= limbno)
106 if (mpi_resize(a, limbno + 1) < 0)
107 return -ENOMEM;
108 a->nlimbs = limbno + 1;
109 }
110 a->d[limbno] |= (A_LIMB_1 << bitno);
111 return 0;
112}
113
114/****************
115 * Set bit N of A. and clear all bits above
116 */
117int mpi_set_highbit(MPI a, unsigned n)
118{
119 unsigned limbno, bitno;
120
121 limbno = n / BITS_PER_MPI_LIMB;
122 bitno = n % BITS_PER_MPI_LIMB;
123
124 if (limbno >= a->nlimbs) { /* resize */
125 if (a->alloced >= limbno)
126 if (mpi_resize(a, limbno + 1) < 0)
127 return -ENOMEM;
128 a->nlimbs = limbno + 1;
129 }
130 a->d[limbno] |= (A_LIMB_1 << bitno);
131 for (bitno++; bitno < BITS_PER_MPI_LIMB; bitno++)
132 a->d[limbno] &= ~(A_LIMB_1 << bitno);
133 a->nlimbs = limbno + 1;
134 return 0;
135}
136
137/****************
138 * clear bit N of A and all bits above
139 */
140void mpi_clear_highbit(MPI a, unsigned n)
141{
142 unsigned limbno, bitno;
143
144 limbno = n / BITS_PER_MPI_LIMB;
145 bitno = n % BITS_PER_MPI_LIMB;
146
147 if (limbno >= a->nlimbs)
148 return; /* not allocated, so need to clear bits :-) */
149
150 for (; bitno < BITS_PER_MPI_LIMB; bitno++)
151 a->d[limbno] &= ~(A_LIMB_1 << bitno);
152 a->nlimbs = limbno + 1;
153}
154
155/****************
156 * Clear bit N of A.
157 */
158void mpi_clear_bit(MPI a, unsigned n)
159{
160 unsigned limbno, bitno;
161
162 limbno = n / BITS_PER_MPI_LIMB;
163 bitno = n % BITS_PER_MPI_LIMB;
164
165 if (limbno >= a->nlimbs)
166 return; /* don't need to clear this bit, it's to far to left */
167 a->d[limbno] &= ~(A_LIMB_1 << bitno);
168}
169
170/****************
171 * Shift A by N bits to the right
172 * FIXME: should use alloc_limb if X and A are same.
173 */
174int mpi_rshift(MPI x, MPI a, unsigned n)
175{
176 mpi_ptr_t xp;
177 mpi_size_t xsize;
178
179 xsize = a->nlimbs;
180 x->sign = a->sign;
181 if (RESIZE_IF_NEEDED(x, (size_t) xsize) < 0)
182 return -ENOMEM;
183 xp = x->d;
184
185 if (xsize) {
186 mpihelp_rshift(xp, a->d, xsize, n);
187 MPN_NORMALIZE(xp, xsize);
188 }
189 x->nlimbs = xsize;
190 return 0;
191}
192
193/****************
194 * Shift A by COUNT limbs to the left
195 * This is used only within the MPI library
196 */
197int mpi_lshift_limbs(MPI a, unsigned int count)
198{
199 mpi_ptr_t ap = a->d;
200 int n = a->nlimbs;
201 int i;
202
203 if (!count || !n)
204 return 0;
205
206 if (RESIZE_IF_NEEDED(a, n + count) < 0)
207 return -ENOMEM;
208
209 for (i = n - 1; i >= 0; i--)
210 ap[i + count] = ap[i];
211 for (i = 0; i < count; i++)
212 ap[i] = 0;
213 a->nlimbs += count;
214 return 0;
215}
216
217/****************
218 * Shift A by COUNT limbs to the right
219 * This is used only within the MPI library
220 */
221void mpi_rshift_limbs(MPI a, unsigned int count)
222{
223 mpi_ptr_t ap = a->d;
224 mpi_size_t n = a->nlimbs;
225 unsigned int i;
226
227 if (count >= n) {
228 a->nlimbs = 0;
229 return;
230 }
231
232 for (i = 0; i < n - count; i++)
233 ap[i] = ap[i + count];
234 ap[i] = 0;
235 a->nlimbs -= count;
236}
diff --git a/lib/mpi/mpi-pow.c b/lib/mpi/mpi-pow.c
new file mode 100644
index 000000000000..b04a3cf80080
--- /dev/null
+++ b/lib/mpi/mpi-pow.c
@@ -0,0 +1,323 @@
1/* mpi-pow.c - MPI functions
2 * Copyright (C) 1994, 1996, 1998, 2000 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 *
20 * Note: This code is heavily based on the GNU MP Library.
21 * Actually it's the same code with only minor changes in the
22 * way the data is stored; this is to support the abstraction
23 * of an optional secure memory allocation which may be used
24 * to avoid revealing of sensitive data due to paging etc.
25 * The GNU MP Library itself is published under the LGPL;
26 * however I decided to publish this code under the plain GPL.
27 */
28
29#include <linux/string.h>
30#include "mpi-internal.h"
31#include "longlong.h"
32
33/****************
34 * RES = BASE ^ EXP mod MOD
35 */
36int mpi_powm(MPI res, MPI base, MPI exp, MPI mod)
37{
38 mpi_ptr_t mp_marker = NULL, bp_marker = NULL, ep_marker = NULL;
39 mpi_ptr_t xp_marker = NULL;
40 mpi_ptr_t tspace = NULL;
41 mpi_ptr_t rp, ep, mp, bp;
42 mpi_size_t esize, msize, bsize, rsize;
43 int esign, msign, bsign, rsign;
44 mpi_size_t size;
45 int mod_shift_cnt;
46 int negative_result;
47 int assign_rp = 0;
48 mpi_size_t tsize = 0; /* to avoid compiler warning */
49 /* fixme: we should check that the warning is void */
50 int rc = -ENOMEM;
51
52 esize = exp->nlimbs;
53 msize = mod->nlimbs;
54 size = 2 * msize;
55 esign = exp->sign;
56 msign = mod->sign;
57
58 rp = res->d;
59 ep = exp->d;
60
61 if (!msize)
62 msize = 1 / msize; /* provoke a signal */
63
64 if (!esize) {
65 /* Exponent is zero, result is 1 mod MOD, i.e., 1 or 0
66 * depending on if MOD equals 1. */
67 rp[0] = 1;
68 res->nlimbs = (msize == 1 && mod->d[0] == 1) ? 0 : 1;
69 res->sign = 0;
70 goto leave;
71 }
72
73 /* Normalize MOD (i.e. make its most significant bit set) as required by
74 * mpn_divrem. This will make the intermediate values in the calculation
75 * slightly larger, but the correct result is obtained after a final
76 * reduction using the original MOD value. */
77 mp = mp_marker = mpi_alloc_limb_space(msize);
78 if (!mp)
79 goto enomem;
80 count_leading_zeros(mod_shift_cnt, mod->d[msize - 1]);
81 if (mod_shift_cnt)
82 mpihelp_lshift(mp, mod->d, msize, mod_shift_cnt);
83 else
84 MPN_COPY(mp, mod->d, msize);
85
86 bsize = base->nlimbs;
87 bsign = base->sign;
88 if (bsize > msize) { /* The base is larger than the module. Reduce it. */
89 /* Allocate (BSIZE + 1) with space for remainder and quotient.
90 * (The quotient is (bsize - msize + 1) limbs.) */
91 bp = bp_marker = mpi_alloc_limb_space(bsize + 1);
92 if (!bp)
93 goto enomem;
94 MPN_COPY(bp, base->d, bsize);
95 /* We don't care about the quotient, store it above the remainder,
96 * at BP + MSIZE. */
97 mpihelp_divrem(bp + msize, 0, bp, bsize, mp, msize);
98 bsize = msize;
99 /* Canonicalize the base, since we are going to multiply with it
100 * quite a few times. */
101 MPN_NORMALIZE(bp, bsize);
102 } else
103 bp = base->d;
104
105 if (!bsize) {
106 res->nlimbs = 0;
107 res->sign = 0;
108 goto leave;
109 }
110
111 if (res->alloced < size) {
112 /* We have to allocate more space for RES. If any of the input
113 * parameters are identical to RES, defer deallocation of the old
114 * space. */
115 if (rp == ep || rp == mp || rp == bp) {
116 rp = mpi_alloc_limb_space(size);
117 if (!rp)
118 goto enomem;
119 assign_rp = 1;
120 } else {
121 if (mpi_resize(res, size) < 0)
122 goto enomem;
123 rp = res->d;
124 }
125 } else { /* Make BASE, EXP and MOD not overlap with RES. */
126 if (rp == bp) {
127 /* RES and BASE are identical. Allocate temp. space for BASE. */
128 BUG_ON(bp_marker);
129 bp = bp_marker = mpi_alloc_limb_space(bsize);
130 if (!bp)
131 goto enomem;
132 MPN_COPY(bp, rp, bsize);
133 }
134 if (rp == ep) {
135 /* RES and EXP are identical. Allocate temp. space for EXP. */
136 ep = ep_marker = mpi_alloc_limb_space(esize);
137 if (!ep)
138 goto enomem;
139 MPN_COPY(ep, rp, esize);
140 }
141 if (rp == mp) {
142 /* RES and MOD are identical. Allocate temporary space for MOD. */
143 BUG_ON(mp_marker);
144 mp = mp_marker = mpi_alloc_limb_space(msize);
145 if (!mp)
146 goto enomem;
147 MPN_COPY(mp, rp, msize);
148 }
149 }
150
151 MPN_COPY(rp, bp, bsize);
152 rsize = bsize;
153 rsign = bsign;
154
155 {
156 mpi_size_t i;
157 mpi_ptr_t xp;
158 int c;
159 mpi_limb_t e;
160 mpi_limb_t carry_limb;
161 struct karatsuba_ctx karactx;
162
163 xp = xp_marker = mpi_alloc_limb_space(2 * (msize + 1));
164 if (!xp)
165 goto enomem;
166
167 memset(&karactx, 0, sizeof karactx);
168 negative_result = (ep[0] & 1) && base->sign;
169
170 i = esize - 1;
171 e = ep[i];
172 count_leading_zeros(c, e);
173 e = (e << c) << 1; /* shift the exp bits to the left, lose msb */
174 c = BITS_PER_MPI_LIMB - 1 - c;
175
176 /* Main loop.
177 *
178 * Make the result be pointed to alternately by XP and RP. This
179 * helps us avoid block copying, which would otherwise be necessary
180 * with the overlap restrictions of mpihelp_divmod. With 50% probability
181 * the result after this loop will be in the area originally pointed
182 * by RP (==RES->d), and with 50% probability in the area originally
183 * pointed to by XP.
184 */
185
186 for (;;) {
187 while (c) {
188 mpi_ptr_t tp;
189 mpi_size_t xsize;
190
191 /*if (mpihelp_mul_n(xp, rp, rp, rsize) < 0) goto enomem */
192 if (rsize < KARATSUBA_THRESHOLD)
193 mpih_sqr_n_basecase(xp, rp, rsize);
194 else {
195 if (!tspace) {
196 tsize = 2 * rsize;
197 tspace =
198 mpi_alloc_limb_space(tsize);
199 if (!tspace)
200 goto enomem;
201 } else if (tsize < (2 * rsize)) {
202 mpi_free_limb_space(tspace);
203 tsize = 2 * rsize;
204 tspace =
205 mpi_alloc_limb_space(tsize);
206 if (!tspace)
207 goto enomem;
208 }
209 mpih_sqr_n(xp, rp, rsize, tspace);
210 }
211
212 xsize = 2 * rsize;
213 if (xsize > msize) {
214 mpihelp_divrem(xp + msize, 0, xp, xsize,
215 mp, msize);
216 xsize = msize;
217 }
218
219 tp = rp;
220 rp = xp;
221 xp = tp;
222 rsize = xsize;
223
224 if ((mpi_limb_signed_t) e < 0) {
225 /*mpihelp_mul( xp, rp, rsize, bp, bsize ); */
226 if (bsize < KARATSUBA_THRESHOLD) {
227 mpi_limb_t tmp;
228 if (mpihelp_mul
229 (xp, rp, rsize, bp, bsize,
230 &tmp) < 0)
231 goto enomem;
232 } else {
233 if (mpihelp_mul_karatsuba_case
234 (xp, rp, rsize, bp, bsize,
235 &karactx) < 0)
236 goto enomem;
237 }
238
239 xsize = rsize + bsize;
240 if (xsize > msize) {
241 mpihelp_divrem(xp + msize, 0,
242 xp, xsize, mp,
243 msize);
244 xsize = msize;
245 }
246
247 tp = rp;
248 rp = xp;
249 xp = tp;
250 rsize = xsize;
251 }
252 e <<= 1;
253 c--;
254 }
255
256 i--;
257 if (i < 0)
258 break;
259 e = ep[i];
260 c = BITS_PER_MPI_LIMB;
261 }
262
263 /* We shifted MOD, the modulo reduction argument, left MOD_SHIFT_CNT
264 * steps. Adjust the result by reducing it with the original MOD.
265 *
266 * Also make sure the result is put in RES->d (where it already
267 * might be, see above).
268 */
269 if (mod_shift_cnt) {
270 carry_limb =
271 mpihelp_lshift(res->d, rp, rsize, mod_shift_cnt);
272 rp = res->d;
273 if (carry_limb) {
274 rp[rsize] = carry_limb;
275 rsize++;
276 }
277 } else {
278 MPN_COPY(res->d, rp, rsize);
279 rp = res->d;
280 }
281
282 if (rsize >= msize) {
283 mpihelp_divrem(rp + msize, 0, rp, rsize, mp, msize);
284 rsize = msize;
285 }
286
287 /* Remove any leading zero words from the result. */
288 if (mod_shift_cnt)
289 mpihelp_rshift(rp, rp, rsize, mod_shift_cnt);
290 MPN_NORMALIZE(rp, rsize);
291
292 mpihelp_release_karatsuba_ctx(&karactx);
293 }
294
295 if (negative_result && rsize) {
296 if (mod_shift_cnt)
297 mpihelp_rshift(mp, mp, msize, mod_shift_cnt);
298 mpihelp_sub(rp, mp, msize, rp, rsize);
299 rsize = msize;
300 rsign = msign;
301 MPN_NORMALIZE(rp, rsize);
302 }
303 res->nlimbs = rsize;
304 res->sign = rsign;
305
306leave:
307 rc = 0;
308enomem:
309 if (assign_rp)
310 mpi_assign_limb_space(res, rp, size);
311 if (mp_marker)
312 mpi_free_limb_space(mp_marker);
313 if (bp_marker)
314 mpi_free_limb_space(bp_marker);
315 if (ep_marker)
316 mpi_free_limb_space(ep_marker);
317 if (xp_marker)
318 mpi_free_limb_space(xp_marker);
319 if (tspace)
320 mpi_free_limb_space(tspace);
321 return rc;
322}
323EXPORT_SYMBOL_GPL(mpi_powm);
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
new file mode 100644
index 000000000000..fe84bb978e3b
--- /dev/null
+++ b/lib/mpi/mpicoder.c
@@ -0,0 +1,365 @@
1/* mpicoder.c - Coder for the external representation of MPIs
2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 */
20
21#include "mpi-internal.h"
22
23#define DIM(v) (sizeof(v)/sizeof((v)[0]))
24#define MAX_EXTERN_MPI_BITS 16384
25
26static uint8_t asn[15] = /* Object ID is 1.3.14.3.2.26 */
27{ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03,
28 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
29};
30
31MPI do_encode_md(const void *sha_buffer, unsigned nbits)
32{
33 int nframe = (nbits + 7) / 8;
34 uint8_t *frame, *fr_pt;
35 int i = 0, n;
36 size_t asnlen = DIM(asn);
37 MPI a = MPI_NULL;
38
39 if (SHA1_DIGEST_LENGTH + asnlen + 4 > nframe)
40 pr_info("MPI: can't encode a %d bit MD into a %d bits frame\n",
41 (int)(SHA1_DIGEST_LENGTH * 8), (int)nbits);
42
43 /* We encode the MD in this way:
44 *
45 * 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
46 *
47 * PAD consists of FF bytes.
48 */
49 frame = kmalloc(nframe, GFP_KERNEL);
50 if (!frame)
51 return MPI_NULL;
52 n = 0;
53 frame[n++] = 0;
54 frame[n++] = 1; /* block type */
55 i = nframe - SHA1_DIGEST_LENGTH - asnlen - 3;
56
57 if (i <= 1) {
58 pr_info("MPI: message digest encoding failed\n");
59 kfree(frame);
60 return a;
61 }
62
63 memset(frame + n, 0xff, i);
64 n += i;
65 frame[n++] = 0;
66 memcpy(frame + n, &asn, asnlen);
67 n += asnlen;
68 memcpy(frame + n, sha_buffer, SHA1_DIGEST_LENGTH);
69 n += SHA1_DIGEST_LENGTH;
70
71 i = nframe;
72 fr_pt = frame;
73
74 if (n != nframe) {
75 printk
76 ("MPI: message digest encoding failed, frame length is wrong\n");
77 kfree(frame);
78 return a;
79 }
80
81 a = mpi_alloc((nframe + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB);
82 mpi_set_buffer(a, frame, nframe, 0);
83 kfree(frame);
84
85 return a;
86}
87
88MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
89{
90 const uint8_t *buffer = xbuffer;
91 int i, j;
92 unsigned nbits, nbytes, nlimbs, nread = 0;
93 mpi_limb_t a;
94 MPI val = MPI_NULL;
95
96 if (*ret_nread < 2)
97 goto leave;
98 nbits = buffer[0] << 8 | buffer[1];
99
100 if (nbits > MAX_EXTERN_MPI_BITS) {
101 pr_info("MPI: mpi too large (%u bits)\n", nbits);
102 goto leave;
103 }
104 buffer += 2;
105 nread = 2;
106
107 nbytes = (nbits + 7) / 8;
108 nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
109 val = mpi_alloc(nlimbs);
110 if (!val)
111 return MPI_NULL;
112 i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
113 i %= BYTES_PER_MPI_LIMB;
114 val->nbits = nbits;
115 j = val->nlimbs = nlimbs;
116 val->sign = 0;
117 for (; j > 0; j--) {
118 a = 0;
119 for (; i < BYTES_PER_MPI_LIMB; i++) {
120 if (++nread > *ret_nread) {
121 printk
122 ("MPI: mpi larger than buffer nread=%d ret_nread=%d\n",
123 nread, *ret_nread);
124 goto leave;
125 }
126 a <<= 8;
127 a |= *buffer++;
128 }
129 i = 0;
130 val->d[j - 1] = a;
131 }
132
133leave:
134 *ret_nread = nread;
135 return val;
136}
137EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
138
139/****************
140 * Make an mpi from a character string.
141 */
142int mpi_fromstr(MPI val, const char *str)
143{
144 int hexmode = 0, sign = 0, prepend_zero = 0, i, j, c, c1, c2;
145 unsigned nbits, nbytes, nlimbs;
146 mpi_limb_t a;
147
148 if (*str == '-') {
149 sign = 1;
150 str++;
151 }
152 if (*str == '0' && str[1] == 'x')
153 hexmode = 1;
154 else
155 return -EINVAL; /* other bases are not yet supported */
156 str += 2;
157
158 nbits = strlen(str) * 4;
159 if (nbits % 8)
160 prepend_zero = 1;
161 nbytes = (nbits + 7) / 8;
162 nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
163 if (val->alloced < nlimbs)
164 if (!mpi_resize(val, nlimbs))
165 return -ENOMEM;
166 i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
167 i %= BYTES_PER_MPI_LIMB;
168 j = val->nlimbs = nlimbs;
169 val->sign = sign;
170 for (; j > 0; j--) {
171 a = 0;
172 for (; i < BYTES_PER_MPI_LIMB; i++) {
173 if (prepend_zero) {
174 c1 = '0';
175 prepend_zero = 0;
176 } else
177 c1 = *str++;
178 assert(c1);
179 c2 = *str++;
180 assert(c2);
181 if (c1 >= '0' && c1 <= '9')
182 c = c1 - '0';
183 else if (c1 >= 'a' && c1 <= 'f')
184 c = c1 - 'a' + 10;
185 else if (c1 >= 'A' && c1 <= 'F')
186 c = c1 - 'A' + 10;
187 else {
188 mpi_clear(val);
189 return 1;
190 }
191 c <<= 4;
192 if (c2 >= '0' && c2 <= '9')
193 c |= c2 - '0';
194 else if (c2 >= 'a' && c2 <= 'f')
195 c |= c2 - 'a' + 10;
196 else if (c2 >= 'A' && c2 <= 'F')
197 c |= c2 - 'A' + 10;
198 else {
199 mpi_clear(val);
200 return 1;
201 }
202 a <<= 8;
203 a |= c;
204 }
205 i = 0;
206
207 val->d[j - 1] = a;
208 }
209
210 return 0;
211}
212EXPORT_SYMBOL_GPL(mpi_fromstr);
213
214/****************
215 * Special function to get the low 8 bytes from an mpi.
216 * This can be used as a keyid; KEYID is an 2 element array.
217 * Return the low 4 bytes.
218 */
219u32 mpi_get_keyid(const MPI a, u32 *keyid)
220{
221#if BYTES_PER_MPI_LIMB == 4
222 if (keyid) {
223 keyid[0] = a->nlimbs >= 2 ? a->d[1] : 0;
224 keyid[1] = a->nlimbs >= 1 ? a->d[0] : 0;
225 }
226 return a->nlimbs >= 1 ? a->d[0] : 0;
227#elif BYTES_PER_MPI_LIMB == 8
228 if (keyid) {
229 keyid[0] = a->nlimbs ? (u32) (a->d[0] >> 32) : 0;
230 keyid[1] = a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
231 }
232 return a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
233#else
234#error Make this function work with other LIMB sizes
235#endif
236}
237
238/****************
239 * Return an allocated buffer with the MPI (msb first).
240 * NBYTES receives the length of this buffer. Caller must free the
241 * return string (This function does return a 0 byte buffer with NBYTES
242 * set to zero if the value of A is zero. If sign is not NULL, it will
243 * be set to the sign of the A.
244 */
245void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign)
246{
247 uint8_t *p, *buffer;
248 mpi_limb_t alimb;
249 int i;
250 unsigned int n;
251
252 if (sign)
253 *sign = a->sign;
254 *nbytes = n = a->nlimbs * BYTES_PER_MPI_LIMB;
255 if (!n)
256 n++; /* avoid zero length allocation */
257 p = buffer = kmalloc(n, GFP_KERNEL);
258
259 for (i = a->nlimbs - 1; i >= 0; i--) {
260 alimb = a->d[i];
261#if BYTES_PER_MPI_LIMB == 4
262 *p++ = alimb >> 24;
263 *p++ = alimb >> 16;
264 *p++ = alimb >> 8;
265 *p++ = alimb;
266#elif BYTES_PER_MPI_LIMB == 8
267 *p++ = alimb >> 56;
268 *p++ = alimb >> 48;
269 *p++ = alimb >> 40;
270 *p++ = alimb >> 32;
271 *p++ = alimb >> 24;
272 *p++ = alimb >> 16;
273 *p++ = alimb >> 8;
274 *p++ = alimb;
275#else
276#error please implement for this limb size.
277#endif
278 }
279
280 /* this is sub-optimal but we need to do the shift operation
281 * because the caller has to free the returned buffer */
282 for (p = buffer; !*p && *nbytes; p++, --*nbytes)
283 ;
284 if (p != buffer)
285 memmove(buffer, p, *nbytes);
286
287 return buffer;
288}
289EXPORT_SYMBOL_GPL(mpi_get_buffer);
290
291/****************
292 * Use BUFFER to update MPI.
293 */
294int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign)
295{
296 const uint8_t *buffer = xbuffer, *p;
297 mpi_limb_t alimb;
298 int nlimbs;
299 int i;
300
301 nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
302 if (RESIZE_IF_NEEDED(a, nlimbs) < 0)
303 return -ENOMEM;
304 a->sign = sign;
305
306 for (i = 0, p = buffer + nbytes - 1; p >= buffer + BYTES_PER_MPI_LIMB;) {
307#if BYTES_PER_MPI_LIMB == 4
308 alimb = (mpi_limb_t) *p--;
309 alimb |= (mpi_limb_t) *p-- << 8;
310 alimb |= (mpi_limb_t) *p-- << 16;
311 alimb |= (mpi_limb_t) *p-- << 24;
312#elif BYTES_PER_MPI_LIMB == 8
313 alimb = (mpi_limb_t) *p--;
314 alimb |= (mpi_limb_t) *p-- << 8;
315 alimb |= (mpi_limb_t) *p-- << 16;
316 alimb |= (mpi_limb_t) *p-- << 24;
317 alimb |= (mpi_limb_t) *p-- << 32;
318 alimb |= (mpi_limb_t) *p-- << 40;
319 alimb |= (mpi_limb_t) *p-- << 48;
320 alimb |= (mpi_limb_t) *p-- << 56;
321#else
322#error please implement for this limb size.
323#endif
324 a->d[i++] = alimb;
325 }
326 if (p >= buffer) {
327#if BYTES_PER_MPI_LIMB == 4
328 alimb = *p--;
329 if (p >= buffer)
330 alimb |= (mpi_limb_t) *p-- << 8;
331 if (p >= buffer)
332 alimb |= (mpi_limb_t) *p-- << 16;
333 if (p >= buffer)
334 alimb |= (mpi_limb_t) *p-- << 24;
335#elif BYTES_PER_MPI_LIMB == 8
336 alimb = (mpi_limb_t) *p--;
337 if (p >= buffer)
338 alimb |= (mpi_limb_t) *p-- << 8;
339 if (p >= buffer)
340 alimb |= (mpi_limb_t) *p-- << 16;
341 if (p >= buffer)
342 alimb |= (mpi_limb_t) *p-- << 24;
343 if (p >= buffer)
344 alimb |= (mpi_limb_t) *p-- << 32;
345 if (p >= buffer)
346 alimb |= (mpi_limb_t) *p-- << 40;
347 if (p >= buffer)
348 alimb |= (mpi_limb_t) *p-- << 48;
349 if (p >= buffer)
350 alimb |= (mpi_limb_t) *p-- << 56;
351#else
352#error please implement for this limb size.
353#endif
354 a->d[i++] = alimb;
355 }
356 a->nlimbs = i;
357
358 if (i != nlimbs) {
359 pr_emerg("MPI: mpi_set_buffer: Assertion failed (%d != %d)", i,
360 nlimbs);
361 BUG();
362 }
363 return 0;
364}
365EXPORT_SYMBOL_GPL(mpi_set_buffer);
diff --git a/lib/mpi/mpih-cmp.c b/lib/mpi/mpih-cmp.c
new file mode 100644
index 000000000000..b2fd39677f1b
--- /dev/null
+++ b/lib/mpi/mpih-cmp.c
@@ -0,0 +1,56 @@
1/* mpihelp-sub.c - MPI helper functions
2 * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
3 * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
4 *
5 * This file is part of GnuPG.
6 *
7 * GnuPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GnuPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#include "mpi-internal.h"
31
32/****************
33 * Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
34 * There are no restrictions on the relative sizes of
35 * the two arguments.
36 * Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2.
37 */
38int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size)
39{
40 mpi_size_t i;
41 mpi_limb_t op1_word, op2_word;
42
43 for (i = size - 1; i >= 0; i--) {
44 op1_word = op1_ptr[i];
45 op2_word = op2_ptr[i];
46 if (op1_word != op2_word)
47 goto diff;
48 }
49 return 0;
50
51diff:
52 /* This can *not* be simplified to
53 * op2_word - op2_word
54 * since that expression might give signed overflow. */
55 return (op1_word > op2_word) ? 1 : -1;
56}
diff --git a/lib/mpi/mpih-div.c b/lib/mpi/mpih-div.c
new file mode 100644
index 000000000000..87ede162dfab
--- /dev/null
+++ b/lib/mpi/mpih-div.c
@@ -0,0 +1,541 @@
1/* mpihelp-div.c - MPI helper functions
2 * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
3 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
4 *
5 * This file is part of GnuPG.
6 *
7 * GnuPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GnuPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#include "mpi-internal.h"
31#include "longlong.h"
32
33#ifndef UMUL_TIME
34#define UMUL_TIME 1
35#endif
36#ifndef UDIV_TIME
37#define UDIV_TIME UMUL_TIME
38#endif
39
40/* FIXME: We should be using invert_limb (or invert_normalized_limb)
41 * here (not udiv_qrnnd).
42 */
43
44mpi_limb_t
45mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
46 mpi_limb_t divisor_limb)
47{
48 mpi_size_t i;
49 mpi_limb_t n1, n0, r;
50 int dummy;
51
52 /* Botch: Should this be handled at all? Rely on callers? */
53 if (!dividend_size)
54 return 0;
55
56 /* If multiplication is much faster than division, and the
57 * dividend is large, pre-invert the divisor, and use
58 * only multiplications in the inner loop.
59 *
60 * This test should be read:
61 * Does it ever help to use udiv_qrnnd_preinv?
62 * && Does what we save compensate for the inversion overhead?
63 */
64 if (UDIV_TIME > (2 * UMUL_TIME + 6)
65 && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
66 int normalization_steps;
67
68 count_leading_zeros(normalization_steps, divisor_limb);
69 if (normalization_steps) {
70 mpi_limb_t divisor_limb_inverted;
71
72 divisor_limb <<= normalization_steps;
73
74 /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
75 * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
76 * most significant bit (with weight 2**N) implicit.
77 *
78 * Special case for DIVISOR_LIMB == 100...000.
79 */
80 if (!(divisor_limb << 1))
81 divisor_limb_inverted = ~(mpi_limb_t) 0;
82 else
83 udiv_qrnnd(divisor_limb_inverted, dummy,
84 -divisor_limb, 0, divisor_limb);
85
86 n1 = dividend_ptr[dividend_size - 1];
87 r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
88
89 /* Possible optimization:
90 * if (r == 0
91 * && divisor_limb > ((n1 << normalization_steps)
92 * | (dividend_ptr[dividend_size - 2] >> ...)))
93 * ...one division less...
94 */
95 for (i = dividend_size - 2; i >= 0; i--) {
96 n0 = dividend_ptr[i];
97 UDIV_QRNND_PREINV(dummy, r, r,
98 ((n1 << normalization_steps)
99 | (n0 >>
100 (BITS_PER_MPI_LIMB -
101 normalization_steps))),
102 divisor_limb,
103 divisor_limb_inverted);
104 n1 = n0;
105 }
106 UDIV_QRNND_PREINV(dummy, r, r,
107 n1 << normalization_steps,
108 divisor_limb, divisor_limb_inverted);
109 return r >> normalization_steps;
110 } else {
111 mpi_limb_t divisor_limb_inverted;
112
113 /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
114 * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
115 * most significant bit (with weight 2**N) implicit.
116 *
117 * Special case for DIVISOR_LIMB == 100...000.
118 */
119 if (!(divisor_limb << 1))
120 divisor_limb_inverted = ~(mpi_limb_t) 0;
121 else
122 udiv_qrnnd(divisor_limb_inverted, dummy,
123 -divisor_limb, 0, divisor_limb);
124
125 i = dividend_size - 1;
126 r = dividend_ptr[i];
127
128 if (r >= divisor_limb)
129 r = 0;
130 else
131 i--;
132
133 for (; i >= 0; i--) {
134 n0 = dividend_ptr[i];
135 UDIV_QRNND_PREINV(dummy, r, r,
136 n0, divisor_limb,
137 divisor_limb_inverted);
138 }
139 return r;
140 }
141 } else {
142 if (UDIV_NEEDS_NORMALIZATION) {
143 int normalization_steps;
144
145 count_leading_zeros(normalization_steps, divisor_limb);
146 if (normalization_steps) {
147 divisor_limb <<= normalization_steps;
148
149 n1 = dividend_ptr[dividend_size - 1];
150 r = n1 >> (BITS_PER_MPI_LIMB -
151 normalization_steps);
152
153 /* Possible optimization:
154 * if (r == 0
155 * && divisor_limb > ((n1 << normalization_steps)
156 * | (dividend_ptr[dividend_size - 2] >> ...)))
157 * ...one division less...
158 */
159 for (i = dividend_size - 2; i >= 0; i--) {
160 n0 = dividend_ptr[i];
161 udiv_qrnnd(dummy, r, r,
162 ((n1 << normalization_steps)
163 | (n0 >>
164 (BITS_PER_MPI_LIMB -
165 normalization_steps))),
166 divisor_limb);
167 n1 = n0;
168 }
169 udiv_qrnnd(dummy, r, r,
170 n1 << normalization_steps,
171 divisor_limb);
172 return r >> normalization_steps;
173 }
174 }
175 /* No normalization needed, either because udiv_qrnnd doesn't require
176 * it, or because DIVISOR_LIMB is already normalized. */
177 i = dividend_size - 1;
178 r = dividend_ptr[i];
179
180 if (r >= divisor_limb)
181 r = 0;
182 else
183 i--;
184
185 for (; i >= 0; i--) {
186 n0 = dividend_ptr[i];
187 udiv_qrnnd(dummy, r, r, n0, divisor_limb);
188 }
189 return r;
190 }
191}
192
193/* Divide num (NP/NSIZE) by den (DP/DSIZE) and write
194 * the NSIZE-DSIZE least significant quotient limbs at QP
195 * and the DSIZE long remainder at NP. If QEXTRA_LIMBS is
196 * non-zero, generate that many fraction bits and append them after the
197 * other quotient limbs.
198 * Return the most significant limb of the quotient, this is always 0 or 1.
199 *
200 * Preconditions:
201 * 0. NSIZE >= DSIZE.
202 * 1. The most significant bit of the divisor must be set.
203 * 2. QP must either not overlap with the input operands at all, or
204 * QP + DSIZE >= NP must hold true. (This means that it's
205 * possible to put the quotient in the high part of NUM, right after the
206 * remainder in NUM.
207 * 3. NSIZE >= DSIZE, even if QEXTRA_LIMBS is non-zero.
208 */
209
210mpi_limb_t
211mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
212 mpi_ptr_t np, mpi_size_t nsize, mpi_ptr_t dp, mpi_size_t dsize)
213{
214 mpi_limb_t most_significant_q_limb = 0;
215
216 switch (dsize) {
217 case 0:
218 /* We are asked to divide by zero, so go ahead and do it! (To make
219 the compiler not remove this statement, return the value.) */
220 return 1 / dsize;
221
222 case 1:
223 {
224 mpi_size_t i;
225 mpi_limb_t n1;
226 mpi_limb_t d;
227
228 d = dp[0];
229 n1 = np[nsize - 1];
230
231 if (n1 >= d) {
232 n1 -= d;
233 most_significant_q_limb = 1;
234 }
235
236 qp += qextra_limbs;
237 for (i = nsize - 2; i >= 0; i--)
238 udiv_qrnnd(qp[i], n1, n1, np[i], d);
239 qp -= qextra_limbs;
240
241 for (i = qextra_limbs - 1; i >= 0; i--)
242 udiv_qrnnd(qp[i], n1, n1, 0, d);
243
244 np[0] = n1;
245 }
246 break;
247
248 case 2:
249 {
250 mpi_size_t i;
251 mpi_limb_t n1, n0, n2;
252 mpi_limb_t d1, d0;
253
254 np += nsize - 2;
255 d1 = dp[1];
256 d0 = dp[0];
257 n1 = np[1];
258 n0 = np[0];
259
260 if (n1 >= d1 && (n1 > d1 || n0 >= d0)) {
261 sub_ddmmss(n1, n0, n1, n0, d1, d0);
262 most_significant_q_limb = 1;
263 }
264
265 for (i = qextra_limbs + nsize - 2 - 1; i >= 0; i--) {
266 mpi_limb_t q;
267 mpi_limb_t r;
268
269 if (i >= qextra_limbs)
270 np--;
271 else
272 np[0] = 0;
273
274 if (n1 == d1) {
275 /* Q should be either 111..111 or 111..110. Need special
276 * treatment of this rare case as normal division would
277 * give overflow. */
278 q = ~(mpi_limb_t) 0;
279
280 r = n0 + d1;
281 if (r < d1) { /* Carry in the addition? */
282 add_ssaaaa(n1, n0, r - d0,
283 np[0], 0, d0);
284 qp[i] = q;
285 continue;
286 }
287 n1 = d0 - (d0 != 0 ? 1 : 0);
288 n0 = -d0;
289 } else {
290 udiv_qrnnd(q, r, n1, n0, d1);
291 umul_ppmm(n1, n0, d0, q);
292 }
293
294 n2 = np[0];
295q_test:
296 if (n1 > r || (n1 == r && n0 > n2)) {
297 /* The estimated Q was too large. */
298 q--;
299 sub_ddmmss(n1, n0, n1, n0, 0, d0);
300 r += d1;
301 if (r >= d1) /* If not carry, test Q again. */
302 goto q_test;
303 }
304
305 qp[i] = q;
306 sub_ddmmss(n1, n0, r, n2, n1, n0);
307 }
308 np[1] = n1;
309 np[0] = n0;
310 }
311 break;
312
313 default:
314 {
315 mpi_size_t i;
316 mpi_limb_t dX, d1, n0;
317
318 np += nsize - dsize;
319 dX = dp[dsize - 1];
320 d1 = dp[dsize - 2];
321 n0 = np[dsize - 1];
322
323 if (n0 >= dX) {
324 if (n0 > dX
325 || mpihelp_cmp(np, dp, dsize - 1) >= 0) {
326 mpihelp_sub_n(np, np, dp, dsize);
327 n0 = np[dsize - 1];
328 most_significant_q_limb = 1;
329 }
330 }
331
332 for (i = qextra_limbs + nsize - dsize - 1; i >= 0; i--) {
333 mpi_limb_t q;
334 mpi_limb_t n1, n2;
335 mpi_limb_t cy_limb;
336
337 if (i >= qextra_limbs) {
338 np--;
339 n2 = np[dsize];
340 } else {
341 n2 = np[dsize - 1];
342 MPN_COPY_DECR(np + 1, np, dsize - 1);
343 np[0] = 0;
344 }
345
346 if (n0 == dX) {
347 /* This might over-estimate q, but it's probably not worth
348 * the extra code here to find out. */
349 q = ~(mpi_limb_t) 0;
350 } else {
351 mpi_limb_t r;
352
353 udiv_qrnnd(q, r, n0, np[dsize - 1], dX);
354 umul_ppmm(n1, n0, d1, q);
355
356 while (n1 > r
357 || (n1 == r
358 && n0 > np[dsize - 2])) {
359 q--;
360 r += dX;
361 if (r < dX) /* I.e. "carry in previous addition?" */
362 break;
363 n1 -= n0 < d1;
364 n0 -= d1;
365 }
366 }
367
368 /* Possible optimization: We already have (q * n0) and (1 * n1)
369 * after the calculation of q. Taking advantage of that, we
370 * could make this loop make two iterations less. */
371 cy_limb = mpihelp_submul_1(np, dp, dsize, q);
372
373 if (n2 != cy_limb) {
374 mpihelp_add_n(np, np, dp, dsize);
375 q--;
376 }
377
378 qp[i] = q;
379 n0 = np[dsize - 1];
380 }
381 }
382 }
383
384 return most_significant_q_limb;
385}
386
387/****************
388 * Divide (DIVIDEND_PTR,,DIVIDEND_SIZE) by DIVISOR_LIMB.
389 * Write DIVIDEND_SIZE limbs of quotient at QUOT_PTR.
390 * Return the single-limb remainder.
391 * There are no constraints on the value of the divisor.
392 *
393 * QUOT_PTR and DIVIDEND_PTR might point to the same limb.
394 */
395
396mpi_limb_t
397mpihelp_divmod_1(mpi_ptr_t quot_ptr,
398 mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
399 mpi_limb_t divisor_limb)
400{
401 mpi_size_t i;
402 mpi_limb_t n1, n0, r;
403 int dummy;
404
405 if (!dividend_size)
406 return 0;
407
408 /* If multiplication is much faster than division, and the
409 * dividend is large, pre-invert the divisor, and use
410 * only multiplications in the inner loop.
411 *
412 * This test should be read:
413 * Does it ever help to use udiv_qrnnd_preinv?
414 * && Does what we save compensate for the inversion overhead?
415 */
416 if (UDIV_TIME > (2 * UMUL_TIME + 6)
417 && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
418 int normalization_steps;
419
420 count_leading_zeros(normalization_steps, divisor_limb);
421 if (normalization_steps) {
422 mpi_limb_t divisor_limb_inverted;
423
424 divisor_limb <<= normalization_steps;
425
426 /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
427 * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
428 * most significant bit (with weight 2**N) implicit.
429 */
430 /* Special case for DIVISOR_LIMB == 100...000. */
431 if (!(divisor_limb << 1))
432 divisor_limb_inverted = ~(mpi_limb_t) 0;
433 else
434 udiv_qrnnd(divisor_limb_inverted, dummy,
435 -divisor_limb, 0, divisor_limb);
436
437 n1 = dividend_ptr[dividend_size - 1];
438 r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
439
440 /* Possible optimization:
441 * if (r == 0
442 * && divisor_limb > ((n1 << normalization_steps)
443 * | (dividend_ptr[dividend_size - 2] >> ...)))
444 * ...one division less...
445 */
446 for (i = dividend_size - 2; i >= 0; i--) {
447 n0 = dividend_ptr[i];
448 UDIV_QRNND_PREINV(quot_ptr[i + 1], r, r,
449 ((n1 << normalization_steps)
450 | (n0 >>
451 (BITS_PER_MPI_LIMB -
452 normalization_steps))),
453 divisor_limb,
454 divisor_limb_inverted);
455 n1 = n0;
456 }
457 UDIV_QRNND_PREINV(quot_ptr[0], r, r,
458 n1 << normalization_steps,
459 divisor_limb, divisor_limb_inverted);
460 return r >> normalization_steps;
461 } else {
462 mpi_limb_t divisor_limb_inverted;
463
464 /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
465 * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
466 * most significant bit (with weight 2**N) implicit.
467 */
468 /* Special case for DIVISOR_LIMB == 100...000. */
469 if (!(divisor_limb << 1))
470 divisor_limb_inverted = ~(mpi_limb_t) 0;
471 else
472 udiv_qrnnd(divisor_limb_inverted, dummy,
473 -divisor_limb, 0, divisor_limb);
474
475 i = dividend_size - 1;
476 r = dividend_ptr[i];
477
478 if (r >= divisor_limb)
479 r = 0;
480 else
481 quot_ptr[i--] = 0;
482
483 for (; i >= 0; i--) {
484 n0 = dividend_ptr[i];
485 UDIV_QRNND_PREINV(quot_ptr[i], r, r,
486 n0, divisor_limb,
487 divisor_limb_inverted);
488 }
489 return r;
490 }
491 } else {
492 if (UDIV_NEEDS_NORMALIZATION) {
493 int normalization_steps;
494
495 count_leading_zeros(normalization_steps, divisor_limb);
496 if (normalization_steps) {
497 divisor_limb <<= normalization_steps;
498
499 n1 = dividend_ptr[dividend_size - 1];
500 r = n1 >> (BITS_PER_MPI_LIMB -
501 normalization_steps);
502
503 /* Possible optimization:
504 * if (r == 0
505 * && divisor_limb > ((n1 << normalization_steps)
506 * | (dividend_ptr[dividend_size - 2] >> ...)))
507 * ...one division less...
508 */
509 for (i = dividend_size - 2; i >= 0; i--) {
510 n0 = dividend_ptr[i];
511 udiv_qrnnd(quot_ptr[i + 1], r, r,
512 ((n1 << normalization_steps)
513 | (n0 >>
514 (BITS_PER_MPI_LIMB -
515 normalization_steps))),
516 divisor_limb);
517 n1 = n0;
518 }
519 udiv_qrnnd(quot_ptr[0], r, r,
520 n1 << normalization_steps,
521 divisor_limb);
522 return r >> normalization_steps;
523 }
524 }
525 /* No normalization needed, either because udiv_qrnnd doesn't require
526 * it, or because DIVISOR_LIMB is already normalized. */
527 i = dividend_size - 1;
528 r = dividend_ptr[i];
529
530 if (r >= divisor_limb)
531 r = 0;
532 else
533 quot_ptr[i--] = 0;
534
535 for (; i >= 0; i--) {
536 n0 = dividend_ptr[i];
537 udiv_qrnnd(quot_ptr[i], r, r, n0, divisor_limb);
538 }
539 return r;
540 }
541}
diff --git a/lib/mpi/mpih-mul.c b/lib/mpi/mpih-mul.c
new file mode 100644
index 000000000000..c69c5eef233b
--- /dev/null
+++ b/lib/mpi/mpih-mul.c
@@ -0,0 +1,527 @@
1/* mpihelp-mul.c - MPI helper functions
2 * Copyright (C) 1994, 1996, 1998, 1999,
3 * 2000 Free Software Foundation, Inc.
4 *
5 * This file is part of GnuPG.
6 *
7 * GnuPG is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * GnuPG is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
20 *
21 * Note: This code is heavily based on the GNU MP Library.
22 * Actually it's the same code with only minor changes in the
23 * way the data is stored; this is to support the abstraction
24 * of an optional secure memory allocation which may be used
25 * to avoid revealing of sensitive data due to paging etc.
26 * The GNU MP Library itself is published under the LGPL;
27 * however I decided to publish this code under the plain GPL.
28 */
29
30#include <linux/string.h>
31#include "mpi-internal.h"
32#include "longlong.h"
33
34#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
35 do { \
36 if ((size) < KARATSUBA_THRESHOLD) \
37 mul_n_basecase(prodp, up, vp, size); \
38 else \
39 mul_n(prodp, up, vp, size, tspace); \
40 } while (0);
41
42#define MPN_SQR_N_RECURSE(prodp, up, size, tspace) \
43 do { \
44 if ((size) < KARATSUBA_THRESHOLD) \
45 mpih_sqr_n_basecase(prodp, up, size); \
46 else \
47 mpih_sqr_n(prodp, up, size, tspace); \
48 } while (0);
49
50/* Multiply the natural numbers u (pointed to by UP) and v (pointed to by VP),
51 * both with SIZE limbs, and store the result at PRODP. 2 * SIZE limbs are
52 * always stored. Return the most significant limb.
53 *
54 * Argument constraints:
55 * 1. PRODP != UP and PRODP != VP, i.e. the destination
56 * must be distinct from the multiplier and the multiplicand.
57 *
58 *
59 * Handle simple cases with traditional multiplication.
60 *
61 * This is the most critical code of multiplication. All multiplies rely
62 * on this, both small and huge. Small ones arrive here immediately. Huge
63 * ones arrive here as this is the base case for Karatsuba's recursive
64 * algorithm below.
65 */
66
67static mpi_limb_t
68mul_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
69{
70 mpi_size_t i;
71 mpi_limb_t cy;
72 mpi_limb_t v_limb;
73
74 /* Multiply by the first limb in V separately, as the result can be
75 * stored (not added) to PROD. We also avoid a loop for zeroing. */
76 v_limb = vp[0];
77 if (v_limb <= 1) {
78 if (v_limb == 1)
79 MPN_COPY(prodp, up, size);
80 else
81 MPN_ZERO(prodp, size);
82 cy = 0;
83 } else
84 cy = mpihelp_mul_1(prodp, up, size, v_limb);
85
86 prodp[size] = cy;
87 prodp++;
88
89 /* For each iteration in the outer loop, multiply one limb from
90 * U with one limb from V, and add it to PROD. */
91 for (i = 1; i < size; i++) {
92 v_limb = vp[i];
93 if (v_limb <= 1) {
94 cy = 0;
95 if (v_limb == 1)
96 cy = mpihelp_add_n(prodp, prodp, up, size);
97 } else
98 cy = mpihelp_addmul_1(prodp, up, size, v_limb);
99
100 prodp[size] = cy;
101 prodp++;
102 }
103
104 return cy;
105}
106
107static void
108mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp,
109 mpi_size_t size, mpi_ptr_t tspace)
110{
111 if (size & 1) {
112 /* The size is odd, and the code below doesn't handle that.
113 * Multiply the least significant (size - 1) limbs with a recursive
114 * call, and handle the most significant limb of S1 and S2
115 * separately.
116 * A slightly faster way to do this would be to make the Karatsuba
117 * code below behave as if the size were even, and let it check for
118 * odd size in the end. I.e., in essence move this code to the end.
119 * Doing so would save us a recursive call, and potentially make the
120 * stack grow a lot less.
121 */
122 mpi_size_t esize = size - 1; /* even size */
123 mpi_limb_t cy_limb;
124
125 MPN_MUL_N_RECURSE(prodp, up, vp, esize, tspace);
126 cy_limb = mpihelp_addmul_1(prodp + esize, up, esize, vp[esize]);
127 prodp[esize + esize] = cy_limb;
128 cy_limb = mpihelp_addmul_1(prodp + esize, vp, size, up[esize]);
129 prodp[esize + size] = cy_limb;
130 } else {
131 /* Anatolij Alekseevich Karatsuba's divide-and-conquer algorithm.
132 *
133 * Split U in two pieces, U1 and U0, such that
134 * U = U0 + U1*(B**n),
135 * and V in V1 and V0, such that
136 * V = V0 + V1*(B**n).
137 *
138 * UV is then computed recursively using the identity
139 *
140 * 2n n n n
141 * UV = (B + B )U V + B (U -U )(V -V ) + (B + 1)U V
142 * 1 1 1 0 0 1 0 0
143 *
144 * Where B = 2**BITS_PER_MP_LIMB.
145 */
146 mpi_size_t hsize = size >> 1;
147 mpi_limb_t cy;
148 int negflg;
149
150 /* Product H. ________________ ________________
151 * |_____U1 x V1____||____U0 x V0_____|
152 * Put result in upper part of PROD and pass low part of TSPACE
153 * as new TSPACE.
154 */
155 MPN_MUL_N_RECURSE(prodp + size, up + hsize, vp + hsize, hsize,
156 tspace);
157
158 /* Product M. ________________
159 * |_(U1-U0)(V0-V1)_|
160 */
161 if (mpihelp_cmp(up + hsize, up, hsize) >= 0) {
162 mpihelp_sub_n(prodp, up + hsize, up, hsize);
163 negflg = 0;
164 } else {
165 mpihelp_sub_n(prodp, up, up + hsize, hsize);
166 negflg = 1;
167 }
168 if (mpihelp_cmp(vp + hsize, vp, hsize) >= 0) {
169 mpihelp_sub_n(prodp + hsize, vp + hsize, vp, hsize);
170 negflg ^= 1;
171 } else {
172 mpihelp_sub_n(prodp + hsize, vp, vp + hsize, hsize);
173 /* No change of NEGFLG. */
174 }
175 /* Read temporary operands from low part of PROD.
176 * Put result in low part of TSPACE using upper part of TSPACE
177 * as new TSPACE.
178 */
179 MPN_MUL_N_RECURSE(tspace, prodp, prodp + hsize, hsize,
180 tspace + size);
181
182 /* Add/copy product H. */
183 MPN_COPY(prodp + hsize, prodp + size, hsize);
184 cy = mpihelp_add_n(prodp + size, prodp + size,
185 prodp + size + hsize, hsize);
186
187 /* Add product M (if NEGFLG M is a negative number) */
188 if (negflg)
189 cy -=
190 mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace,
191 size);
192 else
193 cy +=
194 mpihelp_add_n(prodp + hsize, prodp + hsize, tspace,
195 size);
196
197 /* Product L. ________________ ________________
198 * |________________||____U0 x V0_____|
199 * Read temporary operands from low part of PROD.
200 * Put result in low part of TSPACE using upper part of TSPACE
201 * as new TSPACE.
202 */
203 MPN_MUL_N_RECURSE(tspace, up, vp, hsize, tspace + size);
204
205 /* Add/copy Product L (twice) */
206
207 cy += mpihelp_add_n(prodp + hsize, prodp + hsize, tspace, size);
208 if (cy)
209 mpihelp_add_1(prodp + hsize + size,
210 prodp + hsize + size, hsize, cy);
211
212 MPN_COPY(prodp, tspace, hsize);
213 cy = mpihelp_add_n(prodp + hsize, prodp + hsize, tspace + hsize,
214 hsize);
215 if (cy)
216 mpihelp_add_1(prodp + size, prodp + size, size, 1);
217 }
218}
219
220void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size)
221{
222 mpi_size_t i;
223 mpi_limb_t cy_limb;
224 mpi_limb_t v_limb;
225
226 /* Multiply by the first limb in V separately, as the result can be
227 * stored (not added) to PROD. We also avoid a loop for zeroing. */
228 v_limb = up[0];
229 if (v_limb <= 1) {
230 if (v_limb == 1)
231 MPN_COPY(prodp, up, size);
232 else
233 MPN_ZERO(prodp, size);
234 cy_limb = 0;
235 } else
236 cy_limb = mpihelp_mul_1(prodp, up, size, v_limb);
237
238 prodp[size] = cy_limb;
239 prodp++;
240
241 /* For each iteration in the outer loop, multiply one limb from
242 * U with one limb from V, and add it to PROD. */
243 for (i = 1; i < size; i++) {
244 v_limb = up[i];
245 if (v_limb <= 1) {
246 cy_limb = 0;
247 if (v_limb == 1)
248 cy_limb = mpihelp_add_n(prodp, prodp, up, size);
249 } else
250 cy_limb = mpihelp_addmul_1(prodp, up, size, v_limb);
251
252 prodp[size] = cy_limb;
253 prodp++;
254 }
255}
256
257void
258mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size, mpi_ptr_t tspace)
259{
260 if (size & 1) {
261 /* The size is odd, and the code below doesn't handle that.
262 * Multiply the least significant (size - 1) limbs with a recursive
263 * call, and handle the most significant limb of S1 and S2
264 * separately.
265 * A slightly faster way to do this would be to make the Karatsuba
266 * code below behave as if the size were even, and let it check for
267 * odd size in the end. I.e., in essence move this code to the end.
268 * Doing so would save us a recursive call, and potentially make the
269 * stack grow a lot less.
270 */
271 mpi_size_t esize = size - 1; /* even size */
272 mpi_limb_t cy_limb;
273
274 MPN_SQR_N_RECURSE(prodp, up, esize, tspace);
275 cy_limb = mpihelp_addmul_1(prodp + esize, up, esize, up[esize]);
276 prodp[esize + esize] = cy_limb;
277 cy_limb = mpihelp_addmul_1(prodp + esize, up, size, up[esize]);
278
279 prodp[esize + size] = cy_limb;
280 } else {
281 mpi_size_t hsize = size >> 1;
282 mpi_limb_t cy;
283
284 /* Product H. ________________ ________________
285 * |_____U1 x U1____||____U0 x U0_____|
286 * Put result in upper part of PROD and pass low part of TSPACE
287 * as new TSPACE.
288 */
289 MPN_SQR_N_RECURSE(prodp + size, up + hsize, hsize, tspace);
290
291 /* Product M. ________________
292 * |_(U1-U0)(U0-U1)_|
293 */
294 if (mpihelp_cmp(up + hsize, up, hsize) >= 0)
295 mpihelp_sub_n(prodp, up + hsize, up, hsize);
296 else
297 mpihelp_sub_n(prodp, up, up + hsize, hsize);
298
299 /* Read temporary operands from low part of PROD.
300 * Put result in low part of TSPACE using upper part of TSPACE
301 * as new TSPACE. */
302 MPN_SQR_N_RECURSE(tspace, prodp, hsize, tspace + size);
303
304 /* Add/copy product H */
305 MPN_COPY(prodp + hsize, prodp + size, hsize);
306 cy = mpihelp_add_n(prodp + size, prodp + size,
307 prodp + size + hsize, hsize);
308
309 /* Add product M (if NEGFLG M is a negative number). */
310 cy -= mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace, size);
311
312 /* Product L. ________________ ________________
313 * |________________||____U0 x U0_____|
314 * Read temporary operands from low part of PROD.
315 * Put result in low part of TSPACE using upper part of TSPACE
316 * as new TSPACE. */
317 MPN_SQR_N_RECURSE(tspace, up, hsize, tspace + size);
318
319 /* Add/copy Product L (twice). */
320 cy += mpihelp_add_n(prodp + hsize, prodp + hsize, tspace, size);
321 if (cy)
322 mpihelp_add_1(prodp + hsize + size,
323 prodp + hsize + size, hsize, cy);
324
325 MPN_COPY(prodp, tspace, hsize);
326 cy = mpihelp_add_n(prodp + hsize, prodp + hsize, tspace + hsize,
327 hsize);
328 if (cy)
329 mpihelp_add_1(prodp + size, prodp + size, size, 1);
330 }
331}
332
333/* This should be made into an inline function in gmp.h. */
334int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
335{
336 if (up == vp) {
337 if (size < KARATSUBA_THRESHOLD)
338 mpih_sqr_n_basecase(prodp, up, size);
339 else {
340 mpi_ptr_t tspace;
341 tspace = mpi_alloc_limb_space(2 * size);
342 if (!tspace)
343 return -ENOMEM;
344 mpih_sqr_n(prodp, up, size, tspace);
345 mpi_free_limb_space(tspace);
346 }
347 } else {
348 if (size < KARATSUBA_THRESHOLD)
349 mul_n_basecase(prodp, up, vp, size);
350 else {
351 mpi_ptr_t tspace;
352 tspace = mpi_alloc_limb_space(2 * size);
353 if (!tspace)
354 return -ENOMEM;
355 mul_n(prodp, up, vp, size, tspace);
356 mpi_free_limb_space(tspace);
357 }
358 }
359
360 return 0;
361}
362
363int
364mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
365 mpi_ptr_t up, mpi_size_t usize,
366 mpi_ptr_t vp, mpi_size_t vsize,
367 struct karatsuba_ctx *ctx)
368{
369 mpi_limb_t cy;
370
371 if (!ctx->tspace || ctx->tspace_size < vsize) {
372 if (ctx->tspace)
373 mpi_free_limb_space(ctx->tspace);
374 ctx->tspace = mpi_alloc_limb_space(2 * vsize);
375 if (!ctx->tspace)
376 return -ENOMEM;
377 ctx->tspace_size = vsize;
378 }
379
380 MPN_MUL_N_RECURSE(prodp, up, vp, vsize, ctx->tspace);
381
382 prodp += vsize;
383 up += vsize;
384 usize -= vsize;
385 if (usize >= vsize) {
386 if (!ctx->tp || ctx->tp_size < vsize) {
387 if (ctx->tp)
388 mpi_free_limb_space(ctx->tp);
389 ctx->tp = mpi_alloc_limb_space(2 * vsize);
390 if (!ctx->tp) {
391 if (ctx->tspace)
392 mpi_free_limb_space(ctx->tspace);
393 ctx->tspace = NULL;
394 return -ENOMEM;
395 }
396 ctx->tp_size = vsize;
397 }
398
399 do {
400 MPN_MUL_N_RECURSE(ctx->tp, up, vp, vsize, ctx->tspace);
401 cy = mpihelp_add_n(prodp, prodp, ctx->tp, vsize);
402 mpihelp_add_1(prodp + vsize, ctx->tp + vsize, vsize,
403 cy);
404 prodp += vsize;
405 up += vsize;
406 usize -= vsize;
407 } while (usize >= vsize);
408 }
409
410 if (usize) {
411 if (usize < KARATSUBA_THRESHOLD) {
412 mpi_limb_t tmp;
413 if (mpihelp_mul(ctx->tspace, vp, vsize, up, usize, &tmp)
414 < 0)
415 return -ENOMEM;
416 } else {
417 if (!ctx->next) {
418 ctx->next = kzalloc(sizeof *ctx, GFP_KERNEL);
419 if (!ctx->next)
420 return -ENOMEM;
421 }
422 if (mpihelp_mul_karatsuba_case(ctx->tspace,
423 vp, vsize,
424 up, usize,
425 ctx->next) < 0)
426 return -ENOMEM;
427 }
428
429 cy = mpihelp_add_n(prodp, prodp, ctx->tspace, vsize);
430 mpihelp_add_1(prodp + vsize, ctx->tspace + vsize, usize, cy);
431 }
432
433 return 0;
434}
435
436void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx)
437{
438 struct karatsuba_ctx *ctx2;
439
440 if (ctx->tp)
441 mpi_free_limb_space(ctx->tp);
442 if (ctx->tspace)
443 mpi_free_limb_space(ctx->tspace);
444 for (ctx = ctx->next; ctx; ctx = ctx2) {
445 ctx2 = ctx->next;
446 if (ctx->tp)
447 mpi_free_limb_space(ctx->tp);
448 if (ctx->tspace)
449 mpi_free_limb_space(ctx->tspace);
450 kfree(ctx);
451 }
452}
453
454/* Multiply the natural numbers u (pointed to by UP, with USIZE limbs)
455 * and v (pointed to by VP, with VSIZE limbs), and store the result at
456 * PRODP. USIZE + VSIZE limbs are always stored, but if the input
457 * operands are normalized. Return the most significant limb of the
458 * result.
459 *
460 * NOTE: The space pointed to by PRODP is overwritten before finished
461 * with U and V, so overlap is an error.
462 *
463 * Argument constraints:
464 * 1. USIZE >= VSIZE.
465 * 2. PRODP != UP and PRODP != VP, i.e. the destination
466 * must be distinct from the multiplier and the multiplicand.
467 */
468
469int
470mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
471 mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result)
472{
473 mpi_ptr_t prod_endp = prodp + usize + vsize - 1;
474 mpi_limb_t cy;
475 struct karatsuba_ctx ctx;
476
477 if (vsize < KARATSUBA_THRESHOLD) {
478 mpi_size_t i;
479 mpi_limb_t v_limb;
480
481 if (!vsize) {
482 *_result = 0;
483 return 0;
484 }
485
486 /* Multiply by the first limb in V separately, as the result can be
487 * stored (not added) to PROD. We also avoid a loop for zeroing. */
488 v_limb = vp[0];
489 if (v_limb <= 1) {
490 if (v_limb == 1)
491 MPN_COPY(prodp, up, usize);
492 else
493 MPN_ZERO(prodp, usize);
494 cy = 0;
495 } else
496 cy = mpihelp_mul_1(prodp, up, usize, v_limb);
497
498 prodp[usize] = cy;
499 prodp++;
500
501 /* For each iteration in the outer loop, multiply one limb from
502 * U with one limb from V, and add it to PROD. */
503 for (i = 1; i < vsize; i++) {
504 v_limb = vp[i];
505 if (v_limb <= 1) {
506 cy = 0;
507 if (v_limb == 1)
508 cy = mpihelp_add_n(prodp, prodp, up,
509 usize);
510 } else
511 cy = mpihelp_addmul_1(prodp, up, usize, v_limb);
512
513 prodp[usize] = cy;
514 prodp++;
515 }
516
517 *_result = cy;
518 return 0;
519 }
520
521 memset(&ctx, 0, sizeof ctx);
522 if (mpihelp_mul_karatsuba_case(prodp, up, usize, vp, vsize, &ctx) < 0)
523 return -ENOMEM;
524 mpihelp_release_karatsuba_ctx(&ctx);
525 *_result = *prod_endp;
526 return 0;
527}
diff --git a/lib/mpi/mpiutil.c b/lib/mpi/mpiutil.c
new file mode 100644
index 000000000000..eefc55d6b7f5
--- /dev/null
+++ b/lib/mpi/mpiutil.c
@@ -0,0 +1,208 @@
1/* mpiutil.ac - Utility functions for MPI
2 * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
3 *
4 * This file is part of GnuPG.
5 *
6 * GnuPG is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * GnuPG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
19 */
20
21#include "mpi-internal.h"
22
23/****************
24 * Note: It was a bad idea to use the number of limbs to allocate
25 * because on a alpha the limbs are large but we normally need
26 * integers of n bits - So we should chnage this to bits (or bytes).
27 *
28 * But mpi_alloc is used in a lot of places :-)
29 */
30MPI mpi_alloc(unsigned nlimbs)
31{
32 MPI a;
33
34 a = kmalloc(sizeof *a, GFP_KERNEL);
35 if (!a)
36 return a;
37
38 if (nlimbs) {
39 a->d = mpi_alloc_limb_space(nlimbs);
40 if (!a->d) {
41 kfree(a);
42 return NULL;
43 }
44 } else {
45 a->d = NULL;
46 }
47
48 a->alloced = nlimbs;
49 a->nlimbs = 0;
50 a->sign = 0;
51 a->flags = 0;
52 a->nbits = 0;
53 return a;
54}
55EXPORT_SYMBOL_GPL(mpi_alloc);
56
57mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
58{
59 size_t len = nlimbs * sizeof(mpi_limb_t);
60
61 return kmalloc(len, GFP_KERNEL);
62}
63
64void mpi_free_limb_space(mpi_ptr_t a)
65{
66 if (!a)
67 return;
68
69 kfree(a);
70}
71
72void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
73{
74 mpi_free_limb_space(a->d);
75 a->d = ap;
76 a->alloced = nlimbs;
77}
78
79/****************
80 * Resize the array of A to NLIMBS. the additional space is cleared
81 * (set to 0) [done by m_realloc()]
82 */
83int mpi_resize(MPI a, unsigned nlimbs)
84{
85 void *p;
86
87 if (nlimbs <= a->alloced)
88 return 0; /* no need to do it */
89
90 if (a->d) {
91 p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
92 if (!p)
93 return -ENOMEM;
94 memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
95 kfree(a->d);
96 a->d = p;
97 } else {
98 a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
99 if (!a->d)
100 return -ENOMEM;
101 }
102 a->alloced = nlimbs;
103 return 0;
104}
105
106void mpi_clear(MPI a)
107{
108 a->nlimbs = 0;
109 a->nbits = 0;
110 a->flags = 0;
111}
112
113void mpi_free(MPI a)
114{
115 if (!a)
116 return;
117
118 if (a->flags & 4)
119 kfree(a->d);
120 else
121 mpi_free_limb_space(a->d);
122
123 if (a->flags & ~7)
124 pr_info("invalid flag value in mpi\n");
125 kfree(a);
126}
127EXPORT_SYMBOL_GPL(mpi_free);
128
129/****************
130 * Note: This copy function should not interpret the MPI
131 * but copy it transparently.
132 */
133int mpi_copy(MPI *copied, const MPI a)
134{
135 size_t i;
136 MPI b;
137
138 *copied = MPI_NULL;
139
140 if (a) {
141 b = mpi_alloc(a->nlimbs);
142 if (!b)
143 return -ENOMEM;
144
145 b->nlimbs = a->nlimbs;
146 b->sign = a->sign;
147 b->flags = a->flags;
148 b->nbits = a->nbits;
149
150 for (i = 0; i < b->nlimbs; i++)
151 b->d[i] = a->d[i];
152
153 *copied = b;
154 }
155
156 return 0;
157}
158
159int mpi_set(MPI w, const MPI u)
160{
161 mpi_ptr_t wp, up;
162 mpi_size_t usize = u->nlimbs;
163 int usign = u->sign;
164
165 if (RESIZE_IF_NEEDED(w, (size_t) usize) < 0)
166 return -ENOMEM;
167
168 wp = w->d;
169 up = u->d;
170 MPN_COPY(wp, up, usize);
171 w->nlimbs = usize;
172 w->nbits = u->nbits;
173 w->flags = u->flags;
174 w->sign = usign;
175 return 0;
176}
177
178int mpi_set_ui(MPI w, unsigned long u)
179{
180 if (RESIZE_IF_NEEDED(w, 1) < 0)
181 return -ENOMEM;
182 w->d[0] = u;
183 w->nlimbs = u ? 1 : 0;
184 w->sign = 0;
185 w->nbits = 0;
186 w->flags = 0;
187 return 0;
188}
189
190MPI mpi_alloc_set_ui(unsigned long u)
191{
192 MPI w = mpi_alloc(1);
193 if (!w)
194 return w;
195 w->d[0] = u;
196 w->nlimbs = u ? 1 : 0;
197 w->sign = 0;
198 return w;
199}
200
201void mpi_swap(MPI a, MPI b)
202{
203 struct gcry_mpi tmp;
204
205 tmp = *a;
206 *a = *b;
207 *b = tmp;
208}
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