1 files changed, 535 insertions, 0 deletions

diff --git a/pwmanager/libcrypt/mpi/mpih-div.c b/pwmanager/libcrypt/mpi/mpih-div.c
new file mode 100644
index 0000000..e41e205
--- a/dev/null
+++ b/pwmanager/libcrypt/mpi/mpih-div.c
@@ -0,0 +1,535 @@
+/* mpih-div.c  -  MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 2000,
+ *               2001, 2002 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#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
+_gcry_mpih_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
+_gcry_mpih_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 || _gcry_mpih_cmp(np, dp, dsize - 1) >= 0 ) {
+                    _gcry_mpih_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 = _gcry_mpih_submul_1(np, dp, dsize, q);
+
+                if( n2 != cy_limb ) {
+                    _gcry_mpih_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
+_gcry_mpih_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;
+    }
+}
+
+