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authorDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-08-31 14:05:16 +0300
committerDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-11-09 11:45:22 +0200
commitcdec9cb5167ab1113ba9c58e395f664d9d3f9acb (patch)
tree7d9a4ab3e86b937354d0151a24d412ea8d56ad43 /lib/mpi
parent1ea6b8f48918282bdca0b32a34095504ee65bab5 (diff)
downloadlinux-linaro-stable-cdec9cb5167ab1113ba9c58e395f664d9d3f9acb.tar.gz
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/mpi')
-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 @@
+/* mpihelp-add_1.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998,
+ * 2000 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_ptr_t s2_ptr, mpi_size_t size)
+{
+ mpi_limb_t x, y, cy;
+ mpi_size_t j;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ the loop becomes faster. */
+ j = -size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ s2_ptr -= j;
+ res_ptr -= j;
+
+ cy = 0;
+ do {
+ y = s2_ptr[j];
+ x = s1_ptr[j];
+ y += cy; /* add previous carry to one addend */
+ cy = y < cy; /* get out carry from that addition */
+ y += x; /* add other addend */
+ cy += y < x; /* get out carry from that add, combine */
+ res_ptr[j] = y;
+ } while (++j);
+
+ return cy;
+}
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 @@
+/* mpihelp-lshift.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+
+/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
+ * and store the USIZE least significant digits of the result at WP.
+ * Return the bits shifted out from the most significant digit.
+ *
+ * Argument constraints:
+ * 1. 0 < CNT < BITS_PER_MP_LIMB
+ * 2. If the result is to be written over the input, WP must be >= UP.
+ */
+
+mpi_limb_t
+mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned int cnt)
+{
+ mpi_limb_t high_limb, low_limb;
+ unsigned sh_1, sh_2;
+ mpi_size_t i;
+ mpi_limb_t retval;
+
+ sh_1 = cnt;
+ wp += 1;
+ sh_2 = BITS_PER_MPI_LIMB - sh_1;
+ i = usize - 1;
+ low_limb = up[i];
+ retval = low_limb >> sh_2;
+ high_limb = low_limb;
+ while (--i >= 0) {
+ low_limb = up[i];
+ wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
+ high_limb = low_limb;
+ }
+ wp[i] = high_limb << sh_1;
+
+ return retval;
+}
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 @@
+/* mpihelp-mul_1.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+ mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+
+ /* The loop counter and index J goes from -S1_SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ res_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
+ res_ptr[j] = prod_low;
+ } while (++j);
+
+ return cy_limb;
+}
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 @@
+/* mpihelp-mul_2.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+ mpi_limb_t x;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+ res_ptr -= j;
+ s1_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
+
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
+
+ x = res_ptr[j];
+ prod_low = x + prod_low;
+ cy_limb += prod_low < x ? 1 : 0;
+ res_ptr[j] = prod_low;
+ } while (++j);
+ return cy_limb;
+}
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 @@
+/* mpihelp-mul_3.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+ mpi_limb_t x;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+ res_ptr -= j;
+ s1_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
+
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb ? 1 : 0) + prod_high;
+
+ x = res_ptr[j];
+ prod_low = x - prod_low;
+ cy_limb += prod_low > x ? 1 : 0;
+ res_ptr[j] = prod_low;
+ } while (++j);
+
+ return cy_limb;
+}
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 @@
+/* mpih-rshift.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 1999,
+ * 2000, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GNUPG
+ *
+ * GNUPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GNUPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+
+/* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right
+ * and store the USIZE least significant limbs of the result at WP.
+ * The bits shifted out to the right are returned.
+ *
+ * Argument constraints:
+ * 1. 0 < CNT < BITS_PER_MP_LIMB
+ * 2. If the result is to be written over the input, WP must be <= UP.
+ */
+
+mpi_limb_t
+mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt)
+{
+ mpi_limb_t high_limb, low_limb;
+ unsigned sh_1, sh_2;
+ mpi_size_t i;
+ mpi_limb_t retval;
+
+ sh_1 = cnt;
+ wp -= 1;
+ sh_2 = BITS_PER_MPI_LIMB - sh_1;
+ high_limb = up[0];
+ retval = high_limb << sh_2;
+ low_limb = high_limb;
+ for (i = 1; i < usize; i++) {
+ high_limb = up[i];
+ wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
+ low_limb = high_limb;
+ }
+ wp[i] = low_limb >> sh_1;
+
+ return retval;
+}
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 @@
+/* mpihelp-add_2.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_ptr_t s2_ptr, mpi_size_t size)
+{
+ mpi_limb_t x, y, cy;
+ mpi_size_t j;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ the loop becomes faster. */
+ j = -size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ s2_ptr -= j;
+ res_ptr -= j;
+
+ cy = 0;
+ do {
+ y = s2_ptr[j];
+ x = s1_ptr[j];
+ y += cy; /* add previous carry to subtrahend */
+ cy = y < cy; /* get out carry from that addition */
+ y = x - y; /* main subtract */
+ cy += y > x; /* get out carry from the subtract, combine */
+ res_ptr[j] = y;
+ } while (++j);
+
+ return cy;
+}
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 @@
+/* mpi-bit.c - MPI bit level fucntions
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+const unsigned char __clz_tab[] = {
+ 0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5,
+ 5, 5, 5, 5, 5, 5, 5, 5,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7,
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+ 8, 8, 8, 8, 8, 8, 8, 8,
+};
+
+#define A_LIMB_1 ((mpi_limb_t) 1)
+
+/****************
+ * Sometimes we have MSL (most significant limbs) which are 0;
+ * this is for some reasons not good, so this function removes them.
+ */
+void mpi_normalize(MPI a)
+{
+ for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--)
+ ;
+}
+
+/****************
+ * Return the number of bits in A.
+ */
+unsigned mpi_get_nbits(MPI a)
+{
+ unsigned n;
+
+ mpi_normalize(a);
+
+ if (a->nlimbs) {
+ mpi_limb_t alimb = a->d[a->nlimbs - 1];
+ if (alimb)
+ count_leading_zeros(n, alimb);
+ else
+ n = BITS_PER_MPI_LIMB;
+ n = BITS_PER_MPI_LIMB - n + (a->nlimbs - 1) * BITS_PER_MPI_LIMB;
+ } else
+ n = 0;
+ return n;
+}
+EXPORT_SYMBOL_GPL(mpi_get_nbits);
+
+/****************
+ * Test whether bit N is set.
+ */
+int mpi_test_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+ mpi_limb_t limb;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return 0; /* too far left: this is a 0 */
+ limb = a->d[limbno];
+ return (limb & (A_LIMB_1 << bitno)) ? 1 : 0;
+}
+
+/****************
+ * Set bit N of A.
+ */
+int mpi_set_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) { /* resize */
+ if (a->alloced >= limbno)
+ if (mpi_resize(a, limbno + 1) < 0)
+ return -ENOMEM;
+ a->nlimbs = limbno + 1;
+ }
+ a->d[limbno] |= (A_LIMB_1 << bitno);
+ return 0;
+}
+
+/****************
+ * Set bit N of A. and clear all bits above
+ */
+int mpi_set_highbit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) { /* resize */
+ if (a->alloced >= limbno)
+ if (mpi_resize(a, limbno + 1) < 0)
+ return -ENOMEM;
+ a->nlimbs = limbno + 1;
+ }
+ a->d[limbno] |= (A_LIMB_1 << bitno);
+ for (bitno++; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno + 1;
+ return 0;
+}
+
+/****************
+ * clear bit N of A and all bits above
+ */
+void mpi_clear_highbit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* not allocated, so need to clear bits :-) */
+
+ for (; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno + 1;
+}
+
+/****************
+ * Clear bit N of A.
+ */
+void mpi_clear_bit(MPI a, unsigned n)
+{
+ unsigned limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* don't need to clear this bit, it's to far to left */
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+}
+
+/****************
+ * Shift A by N bits to the right
+ * FIXME: should use alloc_limb if X and A are same.
+ */
+int mpi_rshift(MPI x, MPI a, unsigned n)
+{
+ mpi_ptr_t xp;
+ mpi_size_t xsize;
+
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ if (RESIZE_IF_NEEDED(x, (size_t) xsize) < 0)
+ return -ENOMEM;
+ xp = x->d;
+
+ if (xsize) {
+ mpihelp_rshift(xp, a->d, xsize, n);
+ MPN_NORMALIZE(xp, xsize);
+ }
+ x->nlimbs = xsize;
+ return 0;
+}
+
+/****************
+ * Shift A by COUNT limbs to the left
+ * This is used only within the MPI library
+ */
+int mpi_lshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap = a->d;
+ int n = a->nlimbs;
+ int i;
+
+ if (!count || !n)
+ return 0;
+
+ if (RESIZE_IF_NEEDED(a, n + count) < 0)
+ return -ENOMEM;
+
+ for (i = n - 1; i >= 0; i--)
+ ap[i + count] = ap[i];
+ for (i = 0; i < count; i++)
+ ap[i] = 0;
+ a->nlimbs += count;
+ return 0;
+}
+
+/****************
+ * Shift A by COUNT limbs to the right
+ * This is used only within the MPI library
+ */
+void mpi_rshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap = a->d;
+ mpi_size_t n = a->nlimbs;
+ unsigned int i;
+
+ if (count >= n) {
+ a->nlimbs = 0;
+ return;
+ }
+
+ for (i = 0; i < n - count; i++)
+ ap[i] = ap[i + count];
+ ap[i] = 0;
+ a->nlimbs -= count;
+}
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 @@
+/* mpi-pow.c - MPI functions
+ * Copyright (C) 1994, 1996, 1998, 2000 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <linux/string.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+/****************
+ * RES = BASE ^ EXP mod MOD
+ */
+int mpi_powm(MPI res, MPI base, MPI exp, MPI mod)
+{
+ mpi_ptr_t mp_marker = NULL, bp_marker = NULL, ep_marker = NULL;
+ mpi_ptr_t xp_marker = NULL;
+ mpi_ptr_t tspace = NULL;
+ mpi_ptr_t rp, ep, mp, bp;
+ mpi_size_t esize, msize, bsize, rsize;
+ int esign, msign, bsign, rsign;
+ mpi_size_t size;
+ int mod_shift_cnt;
+ int negative_result;
+ int assign_rp = 0;
+ mpi_size_t tsize = 0; /* to avoid compiler warning */
+ /* fixme: we should check that the warning is void */
+ int rc = -ENOMEM;
+
+ esize = exp->nlimbs;
+ msize = mod->nlimbs;
+ size = 2 * msize;
+ esign = exp->sign;
+ msign = mod->sign;
+
+ rp = res->d;
+ ep = exp->d;
+
+ if (!msize)
+ msize = 1 / msize; /* provoke a signal */
+
+ if (!esize) {
+ /* Exponent is zero, result is 1 mod MOD, i.e., 1 or 0
+ * depending on if MOD equals 1. */
+ rp[0] = 1;
+ res->nlimbs = (msize == 1 && mod->d[0] == 1) ? 0 : 1;
+ res->sign = 0;
+ goto leave;
+ }
+
+ /* Normalize MOD (i.e. make its most significant bit set) as required by
+ * mpn_divrem. This will make the intermediate values in the calculation
+ * slightly larger, but the correct result is obtained after a final
+ * reduction using the original MOD value. */
+ mp = mp_marker = mpi_alloc_limb_space(msize);
+ if (!mp)
+ goto enomem;
+ count_leading_zeros(mod_shift_cnt, mod->d[msize - 1]);
+ if (mod_shift_cnt)
+ mpihelp_lshift(mp, mod->d, msize, mod_shift_cnt);
+ else
+ MPN_COPY(mp, mod->d, msize);
+
+ bsize = base->nlimbs;
+ bsign = base->sign;
+ if (bsize > msize) { /* The base is larger than the module. Reduce it. */
+ /* Allocate (BSIZE + 1) with space for remainder and quotient.
+ * (The quotient is (bsize - msize + 1) limbs.) */
+ bp = bp_marker = mpi_alloc_limb_space(bsize + 1);
+ if (!bp)
+ goto enomem;
+ MPN_COPY(bp, base->d, bsize);
+ /* We don't care about the quotient, store it above the remainder,
+ * at BP + MSIZE. */
+ mpihelp_divrem(bp + msize, 0, bp, bsize, mp, msize);
+ bsize = msize;
+ /* Canonicalize the base, since we are going to multiply with it
+ * quite a few times. */
+ MPN_NORMALIZE(bp, bsize);
+ } else
+ bp = base->d;
+
+ if (!bsize) {
+ res->nlimbs = 0;
+ res->sign = 0;
+ goto leave;
+ }
+
+ if (res->alloced < size) {
+ /* We have to allocate more space for RES. If any of the input
+ * parameters are identical to RES, defer deallocation of the old
+ * space. */
+ if (rp == ep || rp == mp || rp == bp) {
+ rp = mpi_alloc_limb_space(size);
+ if (!rp)
+ goto enomem;
+ assign_rp = 1;
+ } else {
+ if (mpi_resize(res, size) < 0)
+ goto enomem;
+ rp = res->d;
+ }
+ } else { /* Make BASE, EXP and MOD not overlap with RES. */
+ if (rp == bp) {
+ /* RES and BASE are identical. Allocate temp. space for BASE. */
+ BUG_ON(bp_marker);
+ bp = bp_marker = mpi_alloc_limb_space(bsize);
+ if (!bp)
+ goto enomem;
+ MPN_COPY(bp, rp, bsize);
+ }
+ if (rp == ep) {
+ /* RES and EXP are identical. Allocate temp. space for EXP. */
+ ep = ep_marker = mpi_alloc_limb_space(esize);
+ if (!ep)
+ goto enomem;
+ MPN_COPY(ep, rp, esize);
+ }
+ if (rp == mp) {
+ /* RES and MOD are identical. Allocate temporary space for MOD. */
+ BUG_ON(mp_marker);
+ mp = mp_marker = mpi_alloc_limb_space(msize);
+ if (!mp)
+ goto enomem;
+ MPN_COPY(mp, rp, msize);
+ }
+ }
+
+ MPN_COPY(rp, bp, bsize);
+ rsize = bsize;
+ rsign = bsign;
+
+ {
+ mpi_size_t i;
+ mpi_ptr_t xp;
+ int c;
+ mpi_limb_t e;
+ mpi_limb_t carry_limb;
+ struct karatsuba_ctx karactx;
+
+ xp = xp_marker = mpi_alloc_limb_space(2 * (msize + 1));
+ if (!xp)
+ goto enomem;
+
+ memset(&karactx, 0, sizeof karactx);
+ negative_result = (ep[0] & 1) && base->sign;
+
+ i = esize - 1;
+ e = ep[i];
+ count_leading_zeros(c, e);
+ e = (e << c) << 1; /* shift the exp bits to the left, lose msb */
+ c = BITS_PER_MPI_LIMB - 1 - c;
+
+ /* Main loop.
+ *
+ * Make the result be pointed to alternately by XP and RP. This
+ * helps us avoid block copying, which would otherwise be necessary
+ * with the overlap restrictions of mpihelp_divmod. With 50% probability
+ * the result after this loop will be in the area originally pointed
+ * by RP (==RES->d), and with 50% probability in the area originally
+ * pointed to by XP.
+ */
+
+ for (;;) {
+ while (c) {
+ mpi_ptr_t tp;
+ mpi_size_t xsize;
+
+ /*if (mpihelp_mul_n(xp, rp, rp, rsize) < 0) goto enomem */
+ if (rsize < KARATSUBA_THRESHOLD)
+ mpih_sqr_n_basecase(xp, rp, rsize);
+ else {
+ if (!tspace) {
+ tsize = 2 * rsize;
+ tspace =
+ mpi_alloc_limb_space(tsize);
+ if (!tspace)
+ goto enomem;
+ } else if (tsize < (2 * rsize)) {
+ mpi_free_limb_space(tspace);
+ tsize = 2 * rsize;
+ tspace =
+ mpi_alloc_limb_space(tsize);
+ if (!tspace)
+ goto enomem;
+ }
+ mpih_sqr_n(xp, rp, rsize, tspace);
+ }
+
+ xsize = 2 * rsize;
+ if (xsize > msize) {
+ mpihelp_divrem(xp + msize, 0, xp, xsize,
+ mp, msize);
+ xsize = msize;
+ }
+
+ tp = rp;
+ rp = xp;
+ xp = tp;
+ rsize = xsize;
+
+ if ((mpi_limb_signed_t) e < 0) {
+ /*mpihelp_mul( xp, rp, rsize, bp, bsize ); */
+ if (bsize < KARATSUBA_THRESHOLD) {
+ mpi_limb_t tmp;
+ if (mpihelp_mul
+ (xp, rp, rsize, bp, bsize,
+ &tmp) < 0)
+ goto enomem;
+ } else {
+ if (mpihelp_mul_karatsuba_case
+ (xp, rp, rsize, bp, bsize,
+ &karactx) < 0)
+ goto enomem;
+ }
+
+ xsize = rsize + bsize;
+ if (xsize > msize) {
+ mpihelp_divrem(xp + msize, 0,
+ xp, xsize, mp,
+ msize);
+ xsize = msize;
+ }
+
+ tp = rp;
+ rp = xp;
+ xp = tp;
+ rsize = xsize;
+ }
+ e <<= 1;
+ c--;
+ }
+
+ i--;
+ if (i < 0)
+ break;
+ e = ep[i];
+ c = BITS_PER_MPI_LIMB;
+ }
+
+ /* We shifted MOD, the modulo reduction argument, left MOD_SHIFT_CNT
+ * steps. Adjust the result by reducing it with the original MOD.
+ *
+ * Also make sure the result is put in RES->d (where it already
+ * might be, see above).
+ */
+ if (mod_shift_cnt) {
+ carry_limb =
+ mpihelp_lshift(res->d, rp, rsize, mod_shift_cnt);
+ rp = res->d;
+ if (carry_limb) {
+ rp[rsize] = carry_limb;
+ rsize++;
+ }
+ } else {
+ MPN_COPY(res->d, rp, rsize);
+ rp = res->d;
+ }
+
+ if (rsize >= msize) {
+ mpihelp_divrem(rp + msize, 0, rp, rsize, mp, msize);
+ rsize = msize;
+ }
+
+ /* Remove any leading zero words from the result. */
+ if (mod_shift_cnt)
+ mpihelp_rshift(rp, rp, rsize, mod_shift_cnt);
+ MPN_NORMALIZE(rp, rsize);
+
+ mpihelp_release_karatsuba_ctx(&karactx);
+ }
+
+ if (negative_result && rsize) {
+ if (mod_shift_cnt)
+ mpihelp_rshift(mp, mp, msize, mod_shift_cnt);
+ mpihelp_sub(rp, mp, msize, rp, rsize);
+ rsize = msize;
+ rsign = msign;
+ MPN_NORMALIZE(rp, rsize);
+ }
+ res->nlimbs = rsize;
+ res->sign = rsign;
+
+leave:
+ rc = 0;
+enomem:
+ if (assign_rp)
+ mpi_assign_limb_space(res, rp, size);
+ if (mp_marker)
+ mpi_free_limb_space(mp_marker);
+ if (bp_marker)
+ mpi_free_limb_space(bp_marker);
+ if (ep_marker)
+ mpi_free_limb_space(ep_marker);
+ if (xp_marker)
+ mpi_free_limb_space(xp_marker);
+ if (tspace)
+ mpi_free_limb_space(tspace);
+ return rc;
+}
+EXPORT_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 @@
+/* mpicoder.c - Coder for the external representation of MPIs
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "mpi-internal.h"
+
+#define DIM(v) (sizeof(v)/sizeof((v)[0]))
+#define MAX_EXTERN_MPI_BITS 16384
+
+static uint8_t asn[15] = /* Object ID is 1.3.14.3.2.26 */
+{ 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03,
+ 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
+};
+
+MPI do_encode_md(const void *sha_buffer, unsigned nbits)
+{
+ int nframe = (nbits + 7) / 8;
+ uint8_t *frame, *fr_pt;
+ int i = 0, n;
+ size_t asnlen = DIM(asn);
+ MPI a = MPI_NULL;
+
+ if (SHA1_DIGEST_LENGTH + asnlen + 4 > nframe)
+ pr_info("MPI: can't encode a %d bit MD into a %d bits frame\n",
+ (int)(SHA1_DIGEST_LENGTH * 8), (int)nbits);
+
+ /* We encode the MD in this way:
+ *
+ * 0 A PAD(n bytes) 0 ASN(asnlen bytes) MD(len bytes)
+ *
+ * PAD consists of FF bytes.
+ */
+ frame = kmalloc(nframe, GFP_KERNEL);
+ if (!frame)
+ return MPI_NULL;
+ n = 0;
+ frame[n++] = 0;
+ frame[n++] = 1; /* block type */
+ i = nframe - SHA1_DIGEST_LENGTH - asnlen - 3;
+
+ if (i <= 1) {
+ pr_info("MPI: message digest encoding failed\n");
+ kfree(frame);
+ return a;
+ }
+
+ memset(frame + n, 0xff, i);
+ n += i;
+ frame[n++] = 0;
+ memcpy(frame + n, &asn, asnlen);
+ n += asnlen;
+ memcpy(frame + n, sha_buffer, SHA1_DIGEST_LENGTH);
+ n += SHA1_DIGEST_LENGTH;
+
+ i = nframe;
+ fr_pt = frame;
+
+ if (n != nframe) {
+ printk
+ ("MPI: message digest encoding failed, frame length is wrong\n");
+ kfree(frame);
+ return a;
+ }
+
+ a = mpi_alloc((nframe + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB);
+ mpi_set_buffer(a, frame, nframe, 0);
+ kfree(frame);
+
+ return a;
+}
+
+MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
+{
+ const uint8_t *buffer = xbuffer;
+ int i, j;
+ unsigned nbits, nbytes, nlimbs, nread = 0;
+ mpi_limb_t a;
+ MPI val = MPI_NULL;
+
+ if (*ret_nread < 2)
+ goto leave;
+ nbits = buffer[0] << 8 | buffer[1];
+
+ if (nbits > MAX_EXTERN_MPI_BITS) {
+ pr_info("MPI: mpi too large (%u bits)\n", nbits);
+ goto leave;
+ }
+ buffer += 2;
+ nread = 2;
+
+ nbytes = (nbits + 7) / 8;
+ nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ val = mpi_alloc(nlimbs);
+ if (!val)
+ return MPI_NULL;
+ i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+ i %= BYTES_PER_MPI_LIMB;
+ val->nbits = nbits;
+ j = val->nlimbs = nlimbs;
+ val->sign = 0;
+ for (; j > 0; j--) {
+ a = 0;
+ for (; i < BYTES_PER_MPI_LIMB; i++) {
+ if (++nread > *ret_nread) {
+ printk
+ ("MPI: mpi larger than buffer nread=%d ret_nread=%d\n",
+ nread, *ret_nread);
+ goto leave;
+ }
+ a <<= 8;
+ a |= *buffer++;
+ }
+ i = 0;
+ val->d[j - 1] = a;
+ }
+
+leave:
+ *ret_nread = nread;
+ return val;
+}
+EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
+
+/****************
+ * Make an mpi from a character string.
+ */
+int mpi_fromstr(MPI val, const char *str)
+{
+ int hexmode = 0, sign = 0, prepend_zero = 0, i, j, c, c1, c2;
+ unsigned nbits, nbytes, nlimbs;
+ mpi_limb_t a;
+
+ if (*str == '-') {
+ sign = 1;
+ str++;
+ }
+ if (*str == '0' && str[1] == 'x')
+ hexmode = 1;
+ else
+ return -EINVAL; /* other bases are not yet supported */
+ str += 2;
+
+ nbits = strlen(str) * 4;
+ if (nbits % 8)
+ prepend_zero = 1;
+ nbytes = (nbits + 7) / 8;
+ nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ if (val->alloced < nlimbs)
+ if (!mpi_resize(val, nlimbs))
+ return -ENOMEM;
+ i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+ i %= BYTES_PER_MPI_LIMB;
+ j = val->nlimbs = nlimbs;
+ val->sign = sign;
+ for (; j > 0; j--) {
+ a = 0;
+ for (; i < BYTES_PER_MPI_LIMB; i++) {
+ if (prepend_zero) {
+ c1 = '0';
+ prepend_zero = 0;
+ } else
+ c1 = *str++;
+ assert(c1);
+ c2 = *str++;
+ assert(c2);
+ if (c1 >= '0' && c1 <= '9')
+ c = c1 - '0';
+ else if (c1 >= 'a' && c1 <= 'f')
+ c = c1 - 'a' + 10;
+ else if (c1 >= 'A' && c1 <= 'F')
+ c = c1 - 'A' + 10;
+ else {
+ mpi_clear(val);
+ return 1;
+ }
+ c <<= 4;
+ if (c2 >= '0' && c2 <= '9')
+ c |= c2 - '0';
+ else if (c2 >= 'a' && c2 <= 'f')
+ c |= c2 - 'a' + 10;
+ else if (c2 >= 'A' && c2 <= 'F')
+ c |= c2 - 'A' + 10;
+ else {
+ mpi_clear(val);
+ return 1;
+ }
+ a <<= 8;
+ a |= c;
+ }
+ i = 0;
+
+ val->d[j - 1] = a;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mpi_fromstr);
+
+/****************
+ * Special function to get the low 8 bytes from an mpi.
+ * This can be used as a keyid; KEYID is an 2 element array.
+ * Return the low 4 bytes.
+ */
+u32 mpi_get_keyid(const MPI a, u32 *keyid)
+{
+#if BYTES_PER_MPI_LIMB == 4
+ if (keyid) {
+ keyid[0] = a->nlimbs >= 2 ? a->d[1] : 0;
+ keyid[1] = a->nlimbs >= 1 ? a->d[0] : 0;
+ }
+ return a->nlimbs >= 1 ? a->d[0] : 0;
+#elif BYTES_PER_MPI_LIMB == 8
+ if (keyid) {
+ keyid[0] = a->nlimbs ? (u32) (a->d[0] >> 32) : 0;
+ keyid[1] = a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
+ }
+ return a->nlimbs ? (u32) (a->d[0] & 0xffffffff) : 0;
+#else
+#error Make this function work with other LIMB sizes
+#endif
+}
+
+/****************
+ * Return an allocated buffer with the MPI (msb first).
+ * NBYTES receives the length of this buffer. Caller must free the
+ * return string (This function does return a 0 byte buffer with NBYTES
+ * set to zero if the value of A is zero. If sign is not NULL, it will
+ * be set to the sign of the A.
+ */
+void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign)
+{
+ uint8_t *p, *buffer;
+ mpi_limb_t alimb;
+ int i;
+ unsigned int n;
+
+ if (sign)
+ *sign = a->sign;
+ *nbytes = n = a->nlimbs * BYTES_PER_MPI_LIMB;
+ if (!n)
+ n++; /* avoid zero length allocation */
+ p = buffer = kmalloc(n, GFP_KERNEL);
+
+ for (i = a->nlimbs - 1; i >= 0; i--) {
+ alimb = a->d[i];
+#if BYTES_PER_MPI_LIMB == 4
+ *p++ = alimb >> 24;
+ *p++ = alimb >> 16;
+ *p++ = alimb >> 8;
+ *p++ = alimb;
+#elif BYTES_PER_MPI_LIMB == 8
+ *p++ = alimb >> 56;
+ *p++ = alimb >> 48;
+ *p++ = alimb >> 40;
+ *p++ = alimb >> 32;
+ *p++ = alimb >> 24;
+ *p++ = alimb >> 16;
+ *p++ = alimb >> 8;
+ *p++ = alimb;
+#else
+#error please implement for this limb size.
+#endif
+ }
+
+ /* this is sub-optimal but we need to do the shift operation
+ * because the caller has to free the returned buffer */
+ for (p = buffer; !*p && *nbytes; p++, --*nbytes)
+ ;
+ if (p != buffer)
+ memmove(buffer, p, *nbytes);
+
+ return buffer;
+}
+EXPORT_SYMBOL_GPL(mpi_get_buffer);
+
+/****************
+ * Use BUFFER to update MPI.
+ */
+int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign)
+{
+ const uint8_t *buffer = xbuffer, *p;
+ mpi_limb_t alimb;
+ int nlimbs;
+ int i;
+
+ nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ if (RESIZE_IF_NEEDED(a, nlimbs) < 0)
+ return -ENOMEM;
+ a->sign = sign;
+
+ for (i = 0, p = buffer + nbytes - 1; p >= buffer + BYTES_PER_MPI_LIMB;) {
+#if BYTES_PER_MPI_LIMB == 4
+ alimb = (mpi_limb_t) *p--;
+ alimb |= (mpi_limb_t) *p-- << 8;
+ alimb |= (mpi_limb_t) *p-- << 16;
+ alimb |= (mpi_limb_t) *p-- << 24;
+#elif BYTES_PER_MPI_LIMB == 8
+ alimb = (mpi_limb_t) *p--;
+ alimb |= (mpi_limb_t) *p-- << 8;
+ alimb |= (mpi_limb_t) *p-- << 16;
+ alimb |= (mpi_limb_t) *p-- << 24;
+ alimb |= (mpi_limb_t) *p-- << 32;
+ alimb |= (mpi_limb_t) *p-- << 40;
+ alimb |= (mpi_limb_t) *p-- << 48;
+ alimb |= (mpi_limb_t) *p-- << 56;
+#else
+#error please implement for this limb size.
+#endif
+ a->d[i++] = alimb;
+ }
+ if (p >= buffer) {
+#if BYTES_PER_MPI_LIMB == 4
+ alimb = *p--;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 8;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 16;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 24;
+#elif BYTES_PER_MPI_LIMB == 8
+ alimb = (mpi_limb_t) *p--;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 8;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 16;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 24;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 32;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 40;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 48;
+ if (p >= buffer)
+ alimb |= (mpi_limb_t) *p-- << 56;
+#else
+#error please implement for this limb size.
+#endif
+ a->d[i++] = alimb;
+ }
+ a->nlimbs = i;
+
+ if (i != nlimbs) {
+ pr_emerg("MPI: mpi_set_buffer: Assertion failed (%d != %d)", i,
+ nlimbs);
+ BUG();
+ }
+ return 0;
+}
+EXPORT_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 @@
+/* mpihelp-sub.c - MPI helper functions
+ * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+
+/****************
+ * Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
+ * There are no restrictions on the relative sizes of
+ * the two arguments.
+ * Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2.
+ */
+int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size)
+{
+ mpi_size_t i;
+ mpi_limb_t op1_word, op2_word;
+
+ for (i = size - 1; i >= 0; i--) {
+ op1_word = op1_ptr[i];
+ op2_word = op2_ptr[i];
+ if (op1_word != op2_word)
+ goto diff;
+ }
+ return 0;
+
+diff:
+ /* This can *not* be simplified to
+ * op2_word - op2_word
+ * since that expression might give signed overflow. */
+ return (op1_word > op2_word) ? 1 : -1;
+}
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 @@
+/* mpihelp-div.c - MPI helper functions
+ * Copyright (C) 1994, 1996 Free Software Foundation, Inc.
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+#ifndef UMUL_TIME
+#define UMUL_TIME 1
+#endif
+#ifndef UDIV_TIME
+#define UDIV_TIME UMUL_TIME
+#endif
+
+/* FIXME: We should be using invert_limb (or invert_normalized_limb)
+ * here (not udiv_qrnnd).
+ */
+
+mpi_limb_t
+mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb)
+{
+ mpi_size_t i;
+ mpi_limb_t n1, n0, r;
+ int dummy;
+
+ /* Botch: Should this be handled at all? Rely on callers? */
+ if (!dividend_size)
+ return 0;
+
+ /* If multiplication is much faster than division, and the
+ * dividend is large, pre-invert the divisor, and use
+ * only multiplications in the inner loop.
+ *
+ * This test should be read:
+ * Does it ever help to use udiv_qrnnd_preinv?
+ * && Does what we save compensate for the inversion overhead?
+ */
+ if (UDIV_TIME > (2 * UMUL_TIME + 6)
+ && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
+ int normalization_steps;
+
+ count_leading_zeros(normalization_steps, divisor_limb);
+ if (normalization_steps) {
+ mpi_limb_t divisor_limb_inverted;
+
+ divisor_limb <<= normalization_steps;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ *
+ * Special case for DIVISOR_LIMB == 100...000.
+ */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t) 0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(dummy, r, r,
+ ((n1 << normalization_steps)
+ | (n0 >>
+ (BITS_PER_MPI_LIMB -
+ normalization_steps))),
+ divisor_limb,
+ divisor_limb_inverted);
+ n1 = n0;
+ }
+ UDIV_QRNND_PREINV(dummy, r, r,
+ n1 << normalization_steps,
+ divisor_limb, divisor_limb_inverted);
+ return r >> normalization_steps;
+ } else {
+ mpi_limb_t divisor_limb_inverted;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ *
+ * Special case for DIVISOR_LIMB == 100...000.
+ */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t) 0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ i--;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(dummy, r, r,
+ n0, divisor_limb,
+ divisor_limb_inverted);
+ }
+ return r;
+ }
+ } else {
+ if (UDIV_NEEDS_NORMALIZATION) {
+ int normalization_steps;
+
+ count_leading_zeros(normalization_steps, divisor_limb);
+ if (normalization_steps) {
+ divisor_limb <<= normalization_steps;
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB -
+ normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(dummy, r, r,
+ ((n1 << normalization_steps)
+ | (n0 >>
+ (BITS_PER_MPI_LIMB -
+ normalization_steps))),
+ divisor_limb);
+ n1 = n0;
+ }
+ udiv_qrnnd(dummy, r, r,
+ n1 << normalization_steps,
+ divisor_limb);
+ return r >> normalization_steps;
+ }
+ }
+ /* No normalization needed, either because udiv_qrnnd doesn't require
+ * it, or because DIVISOR_LIMB is already normalized. */
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ i--;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(dummy, r, r, n0, divisor_limb);
+ }
+ return r;
+ }
+}
+
+/* Divide num (NP/NSIZE) by den (DP/DSIZE) and write
+ * the NSIZE-DSIZE least significant quotient limbs at QP
+ * and the DSIZE long remainder at NP. If QEXTRA_LIMBS is
+ * non-zero, generate that many fraction bits and append them after the
+ * other quotient limbs.
+ * Return the most significant limb of the quotient, this is always 0 or 1.
+ *
+ * Preconditions:
+ * 0. NSIZE >= DSIZE.
+ * 1. The most significant bit of the divisor must be set.
+ * 2. QP must either not overlap with the input operands at all, or
+ * QP + DSIZE >= NP must hold true. (This means that it's
+ * possible to put the quotient in the high part of NUM, right after the
+ * remainder in NUM.
+ * 3. NSIZE >= DSIZE, even if QEXTRA_LIMBS is non-zero.
+ */
+
+mpi_limb_t
+mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
+ mpi_ptr_t np, mpi_size_t nsize, mpi_ptr_t dp, mpi_size_t dsize)
+{
+ mpi_limb_t most_significant_q_limb = 0;
+
+ switch (dsize) {
+ case 0:
+ /* We are asked to divide by zero, so go ahead and do it! (To make
+ the compiler not remove this statement, return the value.) */
+ return 1 / dsize;
+
+ case 1:
+ {
+ mpi_size_t i;
+ mpi_limb_t n1;
+ mpi_limb_t d;
+
+ d = dp[0];
+ n1 = np[nsize - 1];
+
+ if (n1 >= d) {
+ n1 -= d;
+ most_significant_q_limb = 1;
+ }
+
+ qp += qextra_limbs;
+ for (i = nsize - 2; i >= 0; i--)
+ udiv_qrnnd(qp[i], n1, n1, np[i], d);
+ qp -= qextra_limbs;
+
+ for (i = qextra_limbs - 1; i >= 0; i--)
+ udiv_qrnnd(qp[i], n1, n1, 0, d);
+
+ np[0] = n1;
+ }
+ break;
+
+ case 2:
+ {
+ mpi_size_t i;
+ mpi_limb_t n1, n0, n2;
+ mpi_limb_t d1, d0;
+
+ np += nsize - 2;
+ d1 = dp[1];
+ d0 = dp[0];
+ n1 = np[1];
+ n0 = np[0];
+
+ if (n1 >= d1 && (n1 > d1 || n0 >= d0)) {
+ sub_ddmmss(n1, n0, n1, n0, d1, d0);
+ most_significant_q_limb = 1;
+ }
+
+ for (i = qextra_limbs + nsize - 2 - 1; i >= 0; i--) {
+ mpi_limb_t q;
+ mpi_limb_t r;
+
+ if (i >= qextra_limbs)
+ np--;
+ else
+ np[0] = 0;
+
+ if (n1 == d1) {
+ /* Q should be either 111..111 or 111..110. Need special
+ * treatment of this rare case as normal division would
+ * give overflow. */
+ q = ~(mpi_limb_t) 0;
+
+ r = n0 + d1;
+ if (r < d1) { /* Carry in the addition? */
+ add_ssaaaa(n1, n0, r - d0,
+ np[0], 0, d0);
+ qp[i] = q;
+ continue;
+ }
+ n1 = d0 - (d0 != 0 ? 1 : 0);
+ n0 = -d0;
+ } else {
+ udiv_qrnnd(q, r, n1, n0, d1);
+ umul_ppmm(n1, n0, d0, q);
+ }
+
+ n2 = np[0];
+q_test:
+ if (n1 > r || (n1 == r && n0 > n2)) {
+ /* The estimated Q was too large. */
+ q--;
+ sub_ddmmss(n1, n0, n1, n0, 0, d0);
+ r += d1;
+ if (r >= d1) /* If not carry, test Q again. */
+ goto q_test;
+ }
+
+ qp[i] = q;
+ sub_ddmmss(n1, n0, r, n2, n1, n0);
+ }
+ np[1] = n1;
+ np[0] = n0;
+ }
+ break;
+
+ default:
+ {
+ mpi_size_t i;
+ mpi_limb_t dX, d1, n0;
+
+ np += nsize - dsize;
+ dX = dp[dsize - 1];
+ d1 = dp[dsize - 2];
+ n0 = np[dsize - 1];
+
+ if (n0 >= dX) {
+ if (n0 > dX
+ || mpihelp_cmp(np, dp, dsize - 1) >= 0) {
+ mpihelp_sub_n(np, np, dp, dsize);
+ n0 = np[dsize - 1];
+ most_significant_q_limb = 1;
+ }
+ }
+
+ for (i = qextra_limbs + nsize - dsize - 1; i >= 0; i--) {
+ mpi_limb_t q;
+ mpi_limb_t n1, n2;
+ mpi_limb_t cy_limb;
+
+ if (i >= qextra_limbs) {
+ np--;
+ n2 = np[dsize];
+ } else {
+ n2 = np[dsize - 1];
+ MPN_COPY_DECR(np + 1, np, dsize - 1);
+ np[0] = 0;
+ }
+
+ if (n0 == dX) {
+ /* This might over-estimate q, but it's probably not worth
+ * the extra code here to find out. */
+ q = ~(mpi_limb_t) 0;
+ } else {
+ mpi_limb_t r;
+
+ udiv_qrnnd(q, r, n0, np[dsize - 1], dX);
+ umul_ppmm(n1, n0, d1, q);
+
+ while (n1 > r
+ || (n1 == r
+ && n0 > np[dsize - 2])) {
+ q--;
+ r += dX;
+ if (r < dX) /* I.e. "carry in previous addition?" */
+ break;
+ n1 -= n0 < d1;
+ n0 -= d1;
+ }
+ }
+
+ /* Possible optimization: We already have (q * n0) and (1 * n1)
+ * after the calculation of q. Taking advantage of that, we
+ * could make this loop make two iterations less. */
+ cy_limb = mpihelp_submul_1(np, dp, dsize, q);
+
+ if (n2 != cy_limb) {
+ mpihelp_add_n(np, np, dp, dsize);
+ q--;
+ }
+
+ qp[i] = q;
+ n0 = np[dsize - 1];
+ }
+ }
+ }
+
+ return most_significant_q_limb;
+}
+
+/****************
+ * Divide (DIVIDEND_PTR,,DIVIDEND_SIZE) by DIVISOR_LIMB.
+ * Write DIVIDEND_SIZE limbs of quotient at QUOT_PTR.
+ * Return the single-limb remainder.
+ * There are no constraints on the value of the divisor.
+ *
+ * QUOT_PTR and DIVIDEND_PTR might point to the same limb.
+ */
+
+mpi_limb_t
+mpihelp_divmod_1(mpi_ptr_t quot_ptr,
+ mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb)
+{
+ mpi_size_t i;
+ mpi_limb_t n1, n0, r;
+ int dummy;
+
+ if (!dividend_size)
+ return 0;
+
+ /* If multiplication is much faster than division, and the
+ * dividend is large, pre-invert the divisor, and use
+ * only multiplications in the inner loop.
+ *
+ * This test should be read:
+ * Does it ever help to use udiv_qrnnd_preinv?
+ * && Does what we save compensate for the inversion overhead?
+ */
+ if (UDIV_TIME > (2 * UMUL_TIME + 6)
+ && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
+ int normalization_steps;
+
+ count_leading_zeros(normalization_steps, divisor_limb);
+ if (normalization_steps) {
+ mpi_limb_t divisor_limb_inverted;
+
+ divisor_limb <<= normalization_steps;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ */
+ /* Special case for DIVISOR_LIMB == 100...000. */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t) 0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(quot_ptr[i + 1], r, r,
+ ((n1 << normalization_steps)
+ | (n0 >>
+ (BITS_PER_MPI_LIMB -
+ normalization_steps))),
+ divisor_limb,
+ divisor_limb_inverted);
+ n1 = n0;
+ }
+ UDIV_QRNND_PREINV(quot_ptr[0], r, r,
+ n1 << normalization_steps,
+ divisor_limb, divisor_limb_inverted);
+ return r >> normalization_steps;
+ } else {
+ mpi_limb_t divisor_limb_inverted;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ */
+ /* Special case for DIVISOR_LIMB == 100...000. */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t) 0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ quot_ptr[i--] = 0;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(quot_ptr[i], r, r,
+ n0, divisor_limb,
+ divisor_limb_inverted);
+ }
+ return r;
+ }
+ } else {
+ if (UDIV_NEEDS_NORMALIZATION) {
+ int normalization_steps;
+
+ count_leading_zeros(normalization_steps, divisor_limb);
+ if (normalization_steps) {
+ divisor_limb <<= normalization_steps;
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB -
+ normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(quot_ptr[i + 1], r, r,
+ ((n1 << normalization_steps)
+ | (n0 >>
+ (BITS_PER_MPI_LIMB -
+ normalization_steps))),
+ divisor_limb);
+ n1 = n0;
+ }
+ udiv_qrnnd(quot_ptr[0], r, r,
+ n1 << normalization_steps,
+ divisor_limb);
+ return r >> normalization_steps;
+ }
+ }
+ /* No normalization needed, either because udiv_qrnnd doesn't require
+ * it, or because DIVISOR_LIMB is already normalized. */
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ quot_ptr[i--] = 0;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(quot_ptr[i], r, r, n0, divisor_limb);
+ }
+ return r;
+ }
+}
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 @@
+/* mpihelp-mul.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 1999,
+ * 2000 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <linux/string.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
+ do { \
+ if ((size) < KARATSUBA_THRESHOLD) \
+ mul_n_basecase(prodp, up, vp, size); \
+ else \
+ mul_n(prodp, up, vp, size, tspace); \
+ } while (0);
+
+#define MPN_SQR_N_RECURSE(prodp, up, size, tspace) \
+ do { \
+ if ((size) < KARATSUBA_THRESHOLD) \
+ mpih_sqr_n_basecase(prodp, up, size); \
+ else \
+ mpih_sqr_n(prodp, up, size, tspace); \
+ } while (0);
+
+/* Multiply the natural numbers u (pointed to by UP) and v (pointed to by VP),
+ * both with SIZE limbs, and store the result at PRODP. 2 * SIZE limbs are
+ * always stored. Return the most significant limb.
+ *
+ * Argument constraints:
+ * 1. PRODP != UP and PRODP != VP, i.e. the destination
+ * must be distinct from the multiplier and the multiplicand.
+ *
+ *
+ * Handle simple cases with traditional multiplication.
+ *
+ * This is the most critical code of multiplication. All multiplies rely
+ * on this, both small and huge. Small ones arrive here immediately. Huge
+ * ones arrive here as this is the base case for Karatsuba's recursive
+ * algorithm below.
+ */
+
+static mpi_limb_t
+mul_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
+{
+ mpi_size_t i;
+ mpi_limb_t cy;
+ mpi_limb_t v_limb;
+
+ /* Multiply by the first limb in V separately, as the result can be
+ * stored (not added) to PROD. We also avoid a loop for zeroing. */
+ v_limb = vp[0];
+ if (v_limb <= 1) {
+ if (v_limb == 1)
+ MPN_COPY(prodp, up, size);
+ else
+ MPN_ZERO(prodp, size);
+ cy = 0;
+ } else
+ cy = mpihelp_mul_1(prodp, up, size, v_limb);
+
+ prodp[size] = cy;
+ prodp++;
+
+ /* For each iteration in the outer loop, multiply one limb from
+ * U with one limb from V, and add it to PROD. */
+ for (i = 1; i < size; i++) {
+ v_limb = vp[i];
+ if (v_limb <= 1) {
+ cy = 0;
+ if (v_limb == 1)
+ cy = mpihelp_add_n(prodp, prodp, up, size);
+ } else
+ cy = mpihelp_addmul_1(prodp, up, size, v_limb);
+
+ prodp[size] = cy;
+ prodp++;
+ }
+
+ return cy;
+}
+
+static void
+mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp,
+ mpi_size_t size, mpi_ptr_t tspace)
+{
+ if (size & 1) {
+ /* The size is odd, and the code below doesn't handle that.
+ * Multiply the least significant (size - 1) limbs with a recursive
+ * call, and handle the most significant limb of S1 and S2
+ * separately.
+ * A slightly faster way to do this would be to make the Karatsuba
+ * code below behave as if the size were even, and let it check for
+ * odd size in the end. I.e., in essence move this code to the end.
+ * Doing so would save us a recursive call, and potentially make the
+ * stack grow a lot less.
+ */
+ mpi_size_t esize = size - 1; /* even size */
+ mpi_limb_t cy_limb;
+
+ MPN_MUL_N_RECURSE(prodp, up, vp, esize, tspace);
+ cy_limb = mpihelp_addmul_1(prodp + esize, up, esize, vp[esize]);
+ prodp[esize + esize] = cy_limb;
+ cy_limb = mpihelp_addmul_1(prodp + esize, vp, size, up[esize]);
+ prodp[esize + size] = cy_limb;
+ } else {
+ /* Anatolij Alekseevich Karatsuba's divide-and-conquer algorithm.
+ *
+ * Split U in two pieces, U1 and U0, such that
+ * U = U0 + U1*(B**n),
+ * and V in V1 and V0, such that
+ * V = V0 + V1*(B**n).
+ *
+ * UV is then computed recursively using the identity
+ *
+ * 2n n n n
+ * UV = (B + B )U V + B (U -U )(V -V ) + (B + 1)U V
+ * 1 1 1 0 0 1 0 0
+ *
+ * Where B = 2**BITS_PER_MP_LIMB.
+ */
+ mpi_size_t hsize = size >> 1;
+ mpi_limb_t cy;
+ int negflg;
+
+ /* Product H. ________________ ________________
+ * |_____U1 x V1____||____U0 x V0_____|
+ * Put result in upper part of PROD and pass low part of TSPACE
+ * as new TSPACE.
+ */
+ MPN_MUL_N_RECURSE(prodp + size, up + hsize, vp + hsize, hsize,
+ tspace);
+
+ /* Product M. ________________
+ * |_(U1-U0)(V0-V1)_|
+ */
+ if (mpihelp_cmp(up + hsize, up, hsize) >= 0) {
+ mpihelp_sub_n(prodp, up + hsize, up, hsize);
+ negflg = 0;
+ } else {
+ mpihelp_sub_n(prodp, up, up + hsize, hsize);
+ negflg = 1;
+ }
+ if (mpihelp_cmp(vp + hsize, vp, hsize) >= 0) {
+ mpihelp_sub_n(prodp + hsize, vp + hsize, vp, hsize);
+ negflg ^= 1;
+ } else {
+ mpihelp_sub_n(prodp + hsize, vp, vp + hsize, hsize);
+ /* No change of NEGFLG. */
+ }
+ /* Read temporary operands from low part of PROD.
+ * Put result in low part of TSPACE using upper part of TSPACE
+ * as new TSPACE.
+ */
+ MPN_MUL_N_RECURSE(tspace, prodp, prodp + hsize, hsize,
+ tspace + size);
+
+ /* Add/copy product H. */
+ MPN_COPY(prodp + hsize, prodp + size, hsize);
+ cy = mpihelp_add_n(prodp + size, prodp + size,
+ prodp + size + hsize, hsize);
+
+ /* Add product M (if NEGFLG M is a negative number) */
+ if (negflg)
+ cy -=
+ mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace,
+ size);
+ else
+ cy +=
+ mpihelp_add_n(prodp + hsize, prodp + hsize, tspace,
+ size);
+
+ /* Product L. ________________ ________________
+ * |________________||____U0 x V0_____|
+ * Read temporary operands from low part of PROD.
+ * Put result in low part of TSPACE using upper part of TSPACE
+ * as new TSPACE.
+ */
+ MPN_MUL_N_RECURSE(tspace, up, vp, hsize, tspace + size);
+
+ /* Add/copy Product L (twice) */
+
+ cy += mpihelp_add_n(prodp + hsize, prodp + hsize, tspace, size);
+ if (cy)
+ mpihelp_add_1(prodp + hsize + size,
+ prodp + hsize + size, hsize, cy);
+
+ MPN_COPY(prodp, tspace, hsize);
+ cy = mpihelp_add_n(prodp + hsize, prodp + hsize, tspace + hsize,
+ hsize);
+ if (cy)
+ mpihelp_add_1(prodp + size, prodp + size, size, 1);
+ }
+}
+
+void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size)
+{
+ mpi_size_t i;
+ mpi_limb_t cy_limb;
+ mpi_limb_t v_limb;
+
+ /* Multiply by the first limb in V separately, as the result can be
+ * stored (not added) to PROD. We also avoid a loop for zeroing. */
+ v_limb = up[0];
+ if (v_limb <= 1) {
+ if (v_limb == 1)
+ MPN_COPY(prodp, up, size);
+ else
+ MPN_ZERO(prodp, size);
+ cy_limb = 0;
+ } else
+ cy_limb = mpihelp_mul_1(prodp, up, size, v_limb);
+
+ prodp[size] = cy_limb;
+ prodp++;
+
+ /* For each iteration in the outer loop, multiply one limb from
+ * U with one limb from V, and add it to PROD. */
+ for (i = 1; i < size; i++) {
+ v_limb = up[i];
+ if (v_limb <= 1) {
+ cy_limb = 0;
+ if (v_limb == 1)
+ cy_limb = mpihelp_add_n(prodp, prodp, up, size);
+ } else
+ cy_limb = mpihelp_addmul_1(prodp, up, size, v_limb);
+
+ prodp[size] = cy_limb;
+ prodp++;
+ }
+}
+
+void
+mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size, mpi_ptr_t tspace)
+{
+ if (size & 1) {
+ /* The size is odd, and the code below doesn't handle that.
+ * Multiply the least significant (size - 1) limbs with a recursive
+ * call, and handle the most significant limb of S1 and S2
+ * separately.
+ * A slightly faster way to do this would be to make the Karatsuba
+ * code below behave as if the size were even, and let it check for
+ * odd size in the end. I.e., in essence move this code to the end.
+ * Doing so would save us a recursive call, and potentially make the
+ * stack grow a lot less.
+ */
+ mpi_size_t esize = size - 1; /* even size */
+ mpi_limb_t cy_limb;
+
+ MPN_SQR_N_RECURSE(prodp, up, esize, tspace);
+ cy_limb = mpihelp_addmul_1(prodp + esize, up, esize, up[esize]);
+ prodp[esize + esize] = cy_limb;
+ cy_limb = mpihelp_addmul_1(prodp + esize, up, size, up[esize]);
+
+ prodp[esize + size] = cy_limb;
+ } else {
+ mpi_size_t hsize = size >> 1;
+ mpi_limb_t cy;
+
+ /* Product H. ________________ ________________
+ * |_____U1 x U1____||____U0 x U0_____|
+ * Put result in upper part of PROD and pass low part of TSPACE
+ * as new TSPACE.
+ */
+ MPN_SQR_N_RECURSE(prodp + size, up + hsize, hsize, tspace);
+
+ /* Product M. ________________
+ * |_(U1-U0)(U0-U1)_|
+ */
+ if (mpihelp_cmp(up + hsize, up, hsize) >= 0)
+ mpihelp_sub_n(prodp, up + hsize, up, hsize);
+ else
+ mpihelp_sub_n(prodp, up, up + hsize, hsize);
+
+ /* Read temporary operands from low part of PROD.
+ * Put result in low part of TSPACE using upper part of TSPACE
+ * as new TSPACE. */
+ MPN_SQR_N_RECURSE(tspace, prodp, hsize, tspace + size);
+
+ /* Add/copy product H */
+ MPN_COPY(prodp + hsize, prodp + size, hsize);
+ cy = mpihelp_add_n(prodp + size, prodp + size,
+ prodp + size + hsize, hsize);
+
+ /* Add product M (if NEGFLG M is a negative number). */
+ cy -= mpihelp_sub_n(prodp + hsize, prodp + hsize, tspace, size);
+
+ /* Product L. ________________ ________________
+ * |________________||____U0 x U0_____|
+ * Read temporary operands from low part of PROD.
+ * Put result in low part of TSPACE using upper part of TSPACE
+ * as new TSPACE. */
+ MPN_SQR_N_RECURSE(tspace, up, hsize, tspace + size);
+
+ /* Add/copy Product L (twice). */
+ cy += mpihelp_add_n(prodp + hsize, prodp + hsize, tspace, size);
+ if (cy)
+ mpihelp_add_1(prodp + hsize + size,
+ prodp + hsize + size, hsize, cy);
+
+ MPN_COPY(prodp, tspace, hsize);
+ cy = mpihelp_add_n(prodp + hsize, prodp + hsize, tspace + hsize,
+ hsize);
+ if (cy)
+ mpihelp_add_1(prodp + size, prodp + size, size, 1);
+ }
+}
+
+/* This should be made into an inline function in gmp.h. */
+int mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
+{
+ if (up == vp) {
+ if (size < KARATSUBA_THRESHOLD)
+ mpih_sqr_n_basecase(prodp, up, size);
+ else {
+ mpi_ptr_t tspace;
+ tspace = mpi_alloc_limb_space(2 * size);
+ if (!tspace)
+ return -ENOMEM;
+ mpih_sqr_n(prodp, up, size, tspace);
+ mpi_free_limb_space(tspace);
+ }
+ } else {
+ if (size < KARATSUBA_THRESHOLD)
+ mul_n_basecase(prodp, up, vp, size);
+ else {
+ mpi_ptr_t tspace;
+ tspace = mpi_alloc_limb_space(2 * size);
+ if (!tspace)
+ return -ENOMEM;
+ mul_n(prodp, up, vp, size, tspace);
+ mpi_free_limb_space(tspace);
+ }
+ }
+
+ return 0;
+}
+
+int
+mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
+ mpi_ptr_t up, mpi_size_t usize,
+ mpi_ptr_t vp, mpi_size_t vsize,
+ struct karatsuba_ctx *ctx)
+{
+ mpi_limb_t cy;
+
+ if (!ctx->tspace || ctx->tspace_size < vsize) {
+ if (ctx->tspace)
+ mpi_free_limb_space(ctx->tspace);
+ ctx->tspace = mpi_alloc_limb_space(2 * vsize);
+ if (!ctx->tspace)
+ return -ENOMEM;
+ ctx->tspace_size = vsize;
+ }
+
+ MPN_MUL_N_RECURSE(prodp, up, vp, vsize, ctx->tspace);
+
+ prodp += vsize;
+ up += vsize;
+ usize -= vsize;
+ if (usize >= vsize) {
+ if (!ctx->tp || ctx->tp_size < vsize) {
+ if (ctx->tp)
+ mpi_free_limb_space(ctx->tp);
+ ctx->tp = mpi_alloc_limb_space(2 * vsize);
+ if (!ctx->tp) {
+ if (ctx->tspace)
+ mpi_free_limb_space(ctx->tspace);
+ ctx->tspace = NULL;
+ return -ENOMEM;
+ }
+ ctx->tp_size = vsize;
+ }
+
+ do {
+ MPN_MUL_N_RECURSE(ctx->tp, up, vp, vsize, ctx->tspace);
+ cy = mpihelp_add_n(prodp, prodp, ctx->tp, vsize);
+ mpihelp_add_1(prodp + vsize, ctx->tp + vsize, vsize,
+ cy);
+ prodp += vsize;
+ up += vsize;
+ usize -= vsize;
+ } while (usize >= vsize);
+ }
+
+ if (usize) {
+ if (usize < KARATSUBA_THRESHOLD) {
+ mpi_limb_t tmp;
+ if (mpihelp_mul(ctx->tspace, vp, vsize, up, usize, &tmp)
+ < 0)
+ return -ENOMEM;
+ } else {
+ if (!ctx->next) {
+ ctx->next = kzalloc(sizeof *ctx, GFP_KERNEL);
+ if (!ctx->next)
+ return -ENOMEM;
+ }
+ if (mpihelp_mul_karatsuba_case(ctx->tspace,
+ vp, vsize,
+ up, usize,
+ ctx->next) < 0)
+ return -ENOMEM;
+ }
+
+ cy = mpihelp_add_n(prodp, prodp, ctx->tspace, vsize);
+ mpihelp_add_1(prodp + vsize, ctx->tspace + vsize, usize, cy);
+ }
+
+ return 0;
+}
+
+void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx *ctx)
+{
+ struct karatsuba_ctx *ctx2;
+
+ if (ctx->tp)
+ mpi_free_limb_space(ctx->tp);
+ if (ctx->tspace)
+ mpi_free_limb_space(ctx->tspace);
+ for (ctx = ctx->next; ctx; ctx = ctx2) {
+ ctx2 = ctx->next;
+ if (ctx->tp)
+ mpi_free_limb_space(ctx->tp);
+ if (ctx->tspace)
+ mpi_free_limb_space(ctx->tspace);
+ kfree(ctx);
+ }
+}
+
+/* Multiply the natural numbers u (pointed to by UP, with USIZE limbs)
+ * and v (pointed to by VP, with VSIZE limbs), and store the result at
+ * PRODP. USIZE + VSIZE limbs are always stored, but if the input
+ * operands are normalized. Return the most significant limb of the
+ * result.
+ *
+ * NOTE: The space pointed to by PRODP is overwritten before finished
+ * with U and V, so overlap is an error.
+ *
+ * Argument constraints:
+ * 1. USIZE >= VSIZE.
+ * 2. PRODP != UP and PRODP != VP, i.e. the destination
+ * must be distinct from the multiplier and the multiplicand.
+ */
+
+int
+mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
+ mpi_ptr_t vp, mpi_size_t vsize, mpi_limb_t *_result)
+{
+ mpi_ptr_t prod_endp = prodp + usize + vsize - 1;
+ mpi_limb_t cy;
+ struct karatsuba_ctx ctx;
+
+ if (vsize < KARATSUBA_THRESHOLD) {
+ mpi_size_t i;
+ mpi_limb_t v_limb;
+
+ if (!vsize) {
+ *_result = 0;
+ return 0;
+ }
+
+ /* Multiply by the first limb in V separately, as the result can be
+ * stored (not added) to PROD. We also avoid a loop for zeroing. */
+ v_limb = vp[0];
+ if (v_limb <= 1) {
+ if (v_limb == 1)
+ MPN_COPY(prodp, up, usize);
+ else
+ MPN_ZERO(prodp, usize);
+ cy = 0;
+ } else
+ cy = mpihelp_mul_1(prodp, up, usize, v_limb);
+
+ prodp[usize] = cy;
+ prodp++;
+
+ /* For each iteration in the outer loop, multiply one limb from
+ * U with one limb from V, and add it to PROD. */
+ for (i = 1; i < vsize; i++) {
+ v_limb = vp[i];
+ if (v_limb <= 1) {
+ cy = 0;
+ if (v_limb == 1)
+ cy = mpihelp_add_n(prodp, prodp, up,
+ usize);
+ } else
+ cy = mpihelp_addmul_1(prodp, up, usize, v_limb);
+
+ prodp[usize] = cy;
+ prodp++;
+ }
+
+ *_result = cy;
+ return 0;
+ }
+
+ memset(&ctx, 0, sizeof ctx);
+ if (mpihelp_mul_karatsuba_case(prodp, up, usize, vp, vsize, &ctx) < 0)
+ return -ENOMEM;
+ mpihelp_release_karatsuba_ctx(&ctx);
+ *_result = *prod_endp;
+ return 0;
+}
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 @@
+/* mpiutil.ac - Utility functions for MPI
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "mpi-internal.h"
+
+/****************
+ * Note: It was a bad idea to use the number of limbs to allocate
+ * because on a alpha the limbs are large but we normally need
+ * integers of n bits - So we should chnage this to bits (or bytes).
+ *
+ * But mpi_alloc is used in a lot of places :-)
+ */
+MPI mpi_alloc(unsigned nlimbs)
+{
+ MPI a;
+
+ a = kmalloc(sizeof *a, GFP_KERNEL);
+ if (!a)
+ return a;
+
+ if (nlimbs) {
+ a->d = mpi_alloc_limb_space(nlimbs);
+ if (!a->d) {
+ kfree(a);
+ return NULL;
+ }
+ } else {
+ a->d = NULL;
+ }
+
+ a->alloced = nlimbs;
+ a->nlimbs = 0;
+ a->sign = 0;
+ a->flags = 0;
+ a->nbits = 0;
+ return a;
+}
+EXPORT_SYMBOL_GPL(mpi_alloc);
+
+mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs)
+{
+ size_t len = nlimbs * sizeof(mpi_limb_t);
+
+ return kmalloc(len, GFP_KERNEL);
+}
+
+void mpi_free_limb_space(mpi_ptr_t a)
+{
+ if (!a)
+ return;
+
+ kfree(a);
+}
+
+void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
+{
+ mpi_free_limb_space(a->d);
+ a->d = ap;
+ a->alloced = nlimbs;
+}
+
+/****************
+ * Resize the array of A to NLIMBS. the additional space is cleared
+ * (set to 0) [done by m_realloc()]
+ */
+int mpi_resize(MPI a, unsigned nlimbs)
+{
+ void *p;
+
+ if (nlimbs <= a->alloced)
+ return 0; /* no need to do it */
+
+ if (a->d) {
+ p = kmalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
+ kfree(a->d);
+ a->d = p;
+ } else {
+ a->d = kzalloc(nlimbs * sizeof(mpi_limb_t), GFP_KERNEL);
+ if (!a->d)
+ return -ENOMEM;
+ }
+ a->alloced = nlimbs;
+ return 0;
+}
+
+void mpi_clear(MPI a)
+{
+ a->nlimbs = 0;
+ a->nbits = 0;
+ a->flags = 0;
+}
+
+void mpi_free(MPI a)
+{
+ if (!a)
+ return;
+
+ if (a->flags & 4)
+ kfree(a->d);
+ else
+ mpi_free_limb_space(a->d);
+
+ if (a->flags & ~7)
+ pr_info("invalid flag value in mpi\n");
+ kfree(a);
+}
+EXPORT_SYMBOL_GPL(mpi_free);
+
+/****************
+ * Note: This copy function should not interpret the MPI
+ * but copy it transparently.
+ */
+int mpi_copy(MPI *copied, const MPI a)
+{
+ size_t i;
+ MPI b;
+
+ *copied = MPI_NULL;
+
+ if (a) {
+ b = mpi_alloc(a->nlimbs);
+ if (!b)
+ return -ENOMEM;
+
+ b->nlimbs = a->nlimbs;
+ b->sign = a->sign;
+ b->flags = a->flags;
+ b->nbits = a->nbits;
+
+ for (i = 0; i < b->nlimbs; i++)
+ b->d[i] = a->d[i];
+
+ *copied = b;
+ }
+
+ return 0;
+}
+
+int mpi_set(MPI w, const MPI u)
+{
+ mpi_ptr_t wp, up;
+ mpi_size_t usize = u->nlimbs;
+ int usign = u->sign;
+
+ if (RESIZE_IF_NEEDED(w, (size_t) usize) < 0)
+ return -ENOMEM;
+
+ wp = w->d;
+ up = u->d;
+ MPN_COPY(wp, up, usize);
+ w->nlimbs = usize;
+ w->nbits = u->nbits;
+ w->flags = u->flags;
+ w->sign = usign;
+ return 0;
+}
+
+int mpi_set_ui(MPI w, unsigned long u)
+{
+ if (RESIZE_IF_NEEDED(w, 1) < 0)
+ return -ENOMEM;
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ w->nbits = 0;
+ w->flags = 0;
+ return 0;
+}
+
+MPI mpi_alloc_set_ui(unsigned long u)
+{
+ MPI w = mpi_alloc(1);
+ if (!w)
+ return w;
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ return w;
+}
+
+void mpi_swap(MPI a, MPI b)
+{
+ struct gcry_mpi tmp;
+
+ tmp = *a;
+ *a = *b;
+ *b = tmp;
+}