diff options
| -rw-r--r-- | lib/mpi/generic_mpih-add1.c | 61 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-lshift.c | 63 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-mul1.c | 57 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-mul2.c | 60 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-mul3.c | 61 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-rshift.c | 63 | ||||
| -rw-r--r-- | lib/mpi/generic_mpih-sub1.c | 60 | ||||
| -rw-r--r-- | lib/mpi/mpi-bit.c | 236 | ||||
| -rw-r--r-- | lib/mpi/mpi-pow.c | 323 | ||||
| -rw-r--r-- | lib/mpi/mpicoder.c | 365 | ||||
| -rw-r--r-- | lib/mpi/mpih-cmp.c | 56 | ||||
| -rw-r--r-- | lib/mpi/mpih-div.c | 541 | ||||
| -rw-r--r-- | lib/mpi/mpih-mul.c | 527 | ||||
| -rw-r--r-- | lib/mpi/mpiutil.c | 208 |
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 00000000000..c94c7dd344b --- /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 00000000000..86318927231 --- /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 00000000000..1668dfd9092 --- /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 00000000000..8a7b29ee174 --- /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 00000000000..f96df327be6 --- /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 00000000000..ffa328818ca --- /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 00000000000..5d98ab7d685 --- /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 00000000000..854c9c6da02 --- /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 00000000000..b04a3cf8008 --- /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 00000000000..fe84bb978e3 --- /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 00000000000..b2fd39677f1 --- /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 00000000000..87ede162dfa --- /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 00000000000..c69c5eef233 --- /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 00000000000..eefc55d6b7f --- /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; +} |