openssl: Move to a module and split thirdparty lib

Same rationale as the previous commits.

1 files changed, 1164 insertions, 0 deletions

diff --git a/thirdparty/openssl/crypto/bn/bn_mul.c b/thirdparty/openssl/crypto/bn/bn_mul.c
new file mode 100644
index 0000000000..b174850b6b
--- /dev/null
+++ b/thirdparty/openssl/crypto/bn/bn_mul.c
@@ -0,0 +1,1164 @@
+/* crypto/bn/bn_mul.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
+#ifndef BN_DEBUG
+# undef NDEBUG                  /* avoid conflicting definitions */
+# define NDEBUG
+#endif
+
+#include <stdio.h>
+#include <assert.h>
+#include "cryptlib.h"
+#include "bn_lcl.h"
+
+#if defined(OPENSSL_NO_ASM) || !defined(OPENSSL_BN_ASM_PART_WORDS)
+/*
+ * Here follows specialised variants of bn_add_words() and bn_sub_words().
+ * They have the property performing operations on arrays of different sizes.
+ * The sizes of those arrays is expressed through cl, which is the common
+ * length ( basicall, min(len(a),len(b)) ), and dl, which is the delta
+ * between the two lengths, calculated as len(a)-len(b). All lengths are the
+ * number of BN_ULONGs...  For the operations that require a result array as
+ * parameter, it must have the length cl+abs(dl). These functions should
+ * probably end up in bn_asm.c as soon as there are assembler counterparts
+ * for the systems that use assembler files.
+ */
+
+BN_ULONG bn_sub_part_words(BN_ULONG *r,
+                           const BN_ULONG *a, const BN_ULONG *b,
+                           int cl, int dl)
+{
+    BN_ULONG c, t;
+
+    assert(cl >= 0);
+    c = bn_sub_words(r, a, b, cl);
+
+    if (dl == 0)
+        return c;
+
+    r += cl;
+    a += cl;
+    b += cl;
+
+    if (dl < 0) {
+# ifdef BN_COUNT
+        fprintf(stderr, "  bn_sub_part_words %d + %d (dl < 0, c = %d)\n", cl,
+                dl, c);
+# endif
+        for (;;) {
+            t = b[0];
+            r[0] = (0 - t - c) & BN_MASK2;
+            if (t != 0)
+                c = 1;
+            if (++dl >= 0)
+                break;
+
+            t = b[1];
+            r[1] = (0 - t - c) & BN_MASK2;
+            if (t != 0)
+                c = 1;
+            if (++dl >= 0)
+                break;
+
+            t = b[2];
+            r[2] = (0 - t - c) & BN_MASK2;
+            if (t != 0)
+                c = 1;
+            if (++dl >= 0)
+                break;
+
+            t = b[3];
+            r[3] = (0 - t - c) & BN_MASK2;
+            if (t != 0)
+                c = 1;
+            if (++dl >= 0)
+                break;
+
+            b += 4;
+            r += 4;
+        }
+    } else {
+        int save_dl = dl;
+# ifdef BN_COUNT
+        fprintf(stderr, "  bn_sub_part_words %d + %d (dl > 0, c = %d)\n", cl,
+                dl, c);
+# endif
+        while (c) {
+            t = a[0];
+            r[0] = (t - c) & BN_MASK2;
+            if (t != 0)
+                c = 0;
+            if (--dl <= 0)
+                break;
+
+            t = a[1];
+            r[1] = (t - c) & BN_MASK2;
+            if (t != 0)
+                c = 0;
+            if (--dl <= 0)
+                break;
+
+            t = a[2];
+            r[2] = (t - c) & BN_MASK2;
+            if (t != 0)
+                c = 0;
+            if (--dl <= 0)
+                break;
+
+            t = a[3];
+            r[3] = (t - c) & BN_MASK2;
+            if (t != 0)
+                c = 0;
+            if (--dl <= 0)
+                break;
+
+            save_dl = dl;
+            a += 4;
+            r += 4;
+        }
+        if (dl > 0) {
+# ifdef BN_COUNT
+            fprintf(stderr, "  bn_sub_part_words %d + %d (dl > 0, c == 0)\n",
+                    cl, dl);
+# endif
+            if (save_dl > dl) {
+                switch (save_dl - dl) {
+                case 1:
+                    r[1] = a[1];
+                    if (--dl <= 0)
+                        break;
+                case 2:
+                    r[2] = a[2];
+                    if (--dl <= 0)
+                        break;
+                case 3:
+                    r[3] = a[3];
+                    if (--dl <= 0)
+                        break;
+                }
+                a += 4;
+                r += 4;
+            }
+        }
+        if (dl > 0) {
+# ifdef BN_COUNT
+            fprintf(stderr, "  bn_sub_part_words %d + %d (dl > 0, copy)\n",
+                    cl, dl);
+# endif
+            for (;;) {
+                r[0] = a[0];
+                if (--dl <= 0)
+                    break;
+                r[1] = a[1];
+                if (--dl <= 0)
+                    break;
+                r[2] = a[2];
+                if (--dl <= 0)
+                    break;
+                r[3] = a[3];
+                if (--dl <= 0)
+                    break;
+
+                a += 4;
+                r += 4;
+            }
+        }
+    }
+    return c;
+}
+#endif
+
+BN_ULONG bn_add_part_words(BN_ULONG *r,
+                           const BN_ULONG *a, const BN_ULONG *b,
+                           int cl, int dl)
+{
+    BN_ULONG c, l, t;
+
+    assert(cl >= 0);
+    c = bn_add_words(r, a, b, cl);
+
+    if (dl == 0)
+        return c;
+
+    r += cl;
+    a += cl;
+    b += cl;
+
+    if (dl < 0) {
+        int save_dl = dl;
+#ifdef BN_COUNT
+        fprintf(stderr, "  bn_add_part_words %d + %d (dl < 0, c = %d)\n", cl,
+                dl, c);
+#endif
+        while (c) {
+            l = (c + b[0]) & BN_MASK2;
+            c = (l < c);
+            r[0] = l;
+            if (++dl >= 0)
+                break;
+
+            l = (c + b[1]) & BN_MASK2;
+            c = (l < c);
+            r[1] = l;
+            if (++dl >= 0)
+                break;
+
+            l = (c + b[2]) & BN_MASK2;
+            c = (l < c);
+            r[2] = l;
+            if (++dl >= 0)
+                break;
+
+            l = (c + b[3]) & BN_MASK2;
+            c = (l < c);
+            r[3] = l;
+            if (++dl >= 0)
+                break;
+
+            save_dl = dl;
+            b += 4;
+            r += 4;
+        }
+        if (dl < 0) {
+#ifdef BN_COUNT
+            fprintf(stderr, "  bn_add_part_words %d + %d (dl < 0, c == 0)\n",
+                    cl, dl);
+#endif
+            if (save_dl < dl) {
+                switch (dl - save_dl) {
+                case 1:
+                    r[1] = b[1];
+                    if (++dl >= 0)
+                        break;
+                case 2:
+                    r[2] = b[2];
+                    if (++dl >= 0)
+                        break;
+                case 3:
+                    r[3] = b[3];
+                    if (++dl >= 0)
+                        break;
+                }
+                b += 4;
+                r += 4;
+            }
+        }
+        if (dl < 0) {
+#ifdef BN_COUNT
+            fprintf(stderr, "  bn_add_part_words %d + %d (dl < 0, copy)\n",
+                    cl, dl);
+#endif
+            for (;;) {
+                r[0] = b[0];
+                if (++dl >= 0)
+                    break;
+                r[1] = b[1];
+                if (++dl >= 0)
+                    break;
+                r[2] = b[2];
+                if (++dl >= 0)
+                    break;
+                r[3] = b[3];
+                if (++dl >= 0)
+                    break;
+
+                b += 4;
+                r += 4;
+            }
+        }
+    } else {
+        int save_dl = dl;
+#ifdef BN_COUNT
+        fprintf(stderr, "  bn_add_part_words %d + %d (dl > 0)\n", cl, dl);
+#endif
+        while (c) {
+            t = (a[0] + c) & BN_MASK2;
+            c = (t < c);
+            r[0] = t;
+            if (--dl <= 0)
+                break;
+
+            t = (a[1] + c) & BN_MASK2;
+            c = (t < c);
+            r[1] = t;
+            if (--dl <= 0)
+                break;
+
+            t = (a[2] + c) & BN_MASK2;
+            c = (t < c);
+            r[2] = t;
+            if (--dl <= 0)
+                break;
+
+            t = (a[3] + c) & BN_MASK2;
+            c = (t < c);
+            r[3] = t;
+            if (--dl <= 0)
+                break;
+
+            save_dl = dl;
+            a += 4;
+            r += 4;
+        }
+#ifdef BN_COUNT
+        fprintf(stderr, "  bn_add_part_words %d + %d (dl > 0, c == 0)\n", cl,
+                dl);
+#endif
+        if (dl > 0) {
+            if (save_dl > dl) {
+                switch (save_dl - dl) {
+                case 1:
+                    r[1] = a[1];
+                    if (--dl <= 0)
+                        break;
+                case 2:
+                    r[2] = a[2];
+                    if (--dl <= 0)
+                        break;
+                case 3:
+                    r[3] = a[3];
+                    if (--dl <= 0)
+                        break;
+                }
+                a += 4;
+                r += 4;
+            }
+        }
+        if (dl > 0) {
+#ifdef BN_COUNT
+            fprintf(stderr, "  bn_add_part_words %d + %d (dl > 0, copy)\n",
+                    cl, dl);
+#endif
+            for (;;) {
+                r[0] = a[0];
+                if (--dl <= 0)
+                    break;
+                r[1] = a[1];
+                if (--dl <= 0)
+                    break;
+                r[2] = a[2];
+                if (--dl <= 0)
+                    break;
+                r[3] = a[3];
+                if (--dl <= 0)
+                    break;
+
+                a += 4;
+                r += 4;
+            }
+        }
+    }
+    return c;
+}
+
+#ifdef BN_RECURSION
+/*
+ * Karatsuba recursive multiplication algorithm (cf. Knuth, The Art of
+ * Computer Programming, Vol. 2)
+ */
+
+/*-
+ * r is 2*n2 words in size,
+ * a and b are both n2 words in size.
+ * n2 must be a power of 2.
+ * We multiply and return the result.
+ * t must be 2*n2 words in size
+ * We calculate
+ * a[0]*b[0]
+ * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0])
+ * a[1]*b[1]
+ */
+/* dnX may not be positive, but n2/2+dnX has to be */
+void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
+                      int dna, int dnb, BN_ULONG *t)
+{
+    int n = n2 / 2, c1, c2;
+    int tna = n + dna, tnb = n + dnb;
+    unsigned int neg, zero;
+    BN_ULONG ln, lo, *p;
+
+# ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_recursive %d%+d * %d%+d\n", n2, dna, n2, dnb);
+# endif
+# ifdef BN_MUL_COMBA
+#  if 0
+    if (n2 == 4) {
+        bn_mul_comba4(r, a, b);
+        return;
+    }
+#  endif
+    /*
+     * Only call bn_mul_comba 8 if n2 == 8 and the two arrays are complete
+     * [steve]
+     */
+    if (n2 == 8 && dna == 0 && dnb == 0) {
+        bn_mul_comba8(r, a, b);
+        return;
+    }
+# endif                         /* BN_MUL_COMBA */
+    /* Else do normal multiply */
+    if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL) {
+        bn_mul_normal(r, a, n2 + dna, b, n2 + dnb);
+        if ((dna + dnb) < 0)
+            memset(&r[2 * n2 + dna + dnb], 0,
+                   sizeof(BN_ULONG) * -(dna + dnb));
+        return;
+    }
+    /* r=(a[0]-a[1])*(b[1]-b[0]) */
+    c1 = bn_cmp_part_words(a, &(a[n]), tna, n - tna);
+    c2 = bn_cmp_part_words(&(b[n]), b, tnb, tnb - n);
+    zero = neg = 0;
+    switch (c1 * 3 + c2) {
+    case -4:
+        bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */
+        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */
+        break;
+    case -3:
+        zero = 1;
+        break;
+    case -2:
+        bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */
+        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); /* + */
+        neg = 1;
+        break;
+    case -1:
+    case 0:
+    case 1:
+        zero = 1;
+        break;
+    case 2:
+        bn_sub_part_words(t, a, &(a[n]), tna, n - tna); /* + */
+        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */
+        neg = 1;
+        break;
+    case 3:
+        zero = 1;
+        break;
+    case 4:
+        bn_sub_part_words(t, a, &(a[n]), tna, n - tna);
+        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n);
+        break;
+    }
+
+# ifdef BN_MUL_COMBA
+    if (n == 4 && dna == 0 && dnb == 0) { /* XXX: bn_mul_comba4 could take
+                                           * extra args to do this well */
+        if (!zero)
+            bn_mul_comba4(&(t[n2]), t, &(t[n]));
+        else
+            memset(&(t[n2]), 0, 8 * sizeof(BN_ULONG));
+
+        bn_mul_comba4(r, a, b);
+        bn_mul_comba4(&(r[n2]), &(a[n]), &(b[n]));
+    } else if (n == 8 && dna == 0 && dnb == 0) { /* XXX: bn_mul_comba8 could
+                                                  * take extra args to do
+                                                  * this well */
+        if (!zero)
+            bn_mul_comba8(&(t[n2]), t, &(t[n]));
+        else
+            memset(&(t[n2]), 0, 16 * sizeof(BN_ULONG));
+
+        bn_mul_comba8(r, a, b);
+        bn_mul_comba8(&(r[n2]), &(a[n]), &(b[n]));
+    } else
+# endif                         /* BN_MUL_COMBA */
+    {
+        p = &(t[n2 * 2]);
+        if (!zero)
+            bn_mul_recursive(&(t[n2]), t, &(t[n]), n, 0, 0, p);
+        else
+            memset(&(t[n2]), 0, n2 * sizeof(BN_ULONG));
+        bn_mul_recursive(r, a, b, n, 0, 0, p);
+        bn_mul_recursive(&(r[n2]), &(a[n]), &(b[n]), n, dna, dnb, p);
+    }
+
+    /*-
+     * t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
+     * r[10] holds (a[0]*b[0])
+     * r[32] holds (b[1]*b[1])
+     */
+
+    c1 = (int)(bn_add_words(t, r, &(r[n2]), n2));
+
+    if (neg) {                  /* if t[32] is negative */
+        c1 -= (int)(bn_sub_words(&(t[n2]), t, &(t[n2]), n2));
+    } else {
+        /* Might have a carry */
+        c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), t, n2));
+    }
+
+    /*-
+     * t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
+     * r[10] holds (a[0]*b[0])
+     * r[32] holds (b[1]*b[1])
+     * c1 holds the carry bits
+     */
+    c1 += (int)(bn_add_words(&(r[n]), &(r[n]), &(t[n2]), n2));
+    if (c1) {
+        p = &(r[n + n2]);
+        lo = *p;
+        ln = (lo + c1) & BN_MASK2;
+        *p = ln;
+
+        /*
+         * The overflow will stop before we over write words we should not
+         * overwrite
+         */
+        if (ln < (BN_ULONG)c1) {
+            do {
+                p++;
+                lo = *p;
+                ln = (lo + 1) & BN_MASK2;
+                *p = ln;
+            } while (ln == 0);
+        }
+    }
+}
+
+/*
+ * n+tn is the word length t needs to be n*4 is size, as does r
+ */
+/* tnX may not be negative but less than n */
+void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n,
+                           int tna, int tnb, BN_ULONG *t)
+{
+    int i, j, n2 = n * 2;
+    int c1, c2, neg;
+    BN_ULONG ln, lo, *p;
+
+# ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_part_recursive (%d%+d) * (%d%+d)\n",
+            n, tna, n, tnb);
+# endif
+    if (n < 8) {
+        bn_mul_normal(r, a, n + tna, b, n + tnb);
+        return;
+    }
+
+    /* r=(a[0]-a[1])*(b[1]-b[0]) */
+    c1 = bn_cmp_part_words(a, &(a[n]), tna, n - tna);
+    c2 = bn_cmp_part_words(&(b[n]), b, tnb, tnb - n);
+    neg = 0;
+    switch (c1 * 3 + c2) {
+    case -4:
+        bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */
+        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */
+        break;
+    case -3:
+        /* break; */
+    case -2:
+        bn_sub_part_words(t, &(a[n]), a, tna, tna - n); /* - */
+        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n); /* + */
+        neg = 1;
+        break;
+    case -1:
+    case 0:
+    case 1:
+        /* break; */
+    case 2:
+        bn_sub_part_words(t, a, &(a[n]), tna, n - tna); /* + */
+        bn_sub_part_words(&(t[n]), b, &(b[n]), tnb, n - tnb); /* - */
+        neg = 1;
+        break;
+    case 3:
+        /* break; */
+    case 4:
+        bn_sub_part_words(t, a, &(a[n]), tna, n - tna);
+        bn_sub_part_words(&(t[n]), &(b[n]), b, tnb, tnb - n);
+        break;
+    }
+    /*
+     * The zero case isn't yet implemented here. The speedup would probably
+     * be negligible.
+     */
+# if 0
+    if (n == 4) {
+        bn_mul_comba4(&(t[n2]), t, &(t[n]));
+        bn_mul_comba4(r, a, b);
+        bn_mul_normal(&(r[n2]), &(a[n]), tn, &(b[n]), tn);
+        memset(&(r[n2 + tn * 2]), 0, sizeof(BN_ULONG) * (n2 - tn * 2));
+    } else
+# endif
+    if (n == 8) {
+        bn_mul_comba8(&(t[n2]), t, &(t[n]));
+        bn_mul_comba8(r, a, b);
+        bn_mul_normal(&(r[n2]), &(a[n]), tna, &(b[n]), tnb);
+        memset(&(r[n2 + tna + tnb]), 0, sizeof(BN_ULONG) * (n2 - tna - tnb));
+    } else {
+        p = &(t[n2 * 2]);
+        bn_mul_recursive(&(t[n2]), t, &(t[n]), n, 0, 0, p);
+        bn_mul_recursive(r, a, b, n, 0, 0, p);
+        i = n / 2;
+        /*
+         * If there is only a bottom half to the number, just do it
+         */
+        if (tna > tnb)
+            j = tna - i;
+        else
+            j = tnb - i;
+        if (j == 0) {
+            bn_mul_recursive(&(r[n2]), &(a[n]), &(b[n]),
+                             i, tna - i, tnb - i, p);
+            memset(&(r[n2 + i * 2]), 0, sizeof(BN_ULONG) * (n2 - i * 2));
+        } else if (j > 0) {     /* eg, n == 16, i == 8 and tn == 11 */
+            bn_mul_part_recursive(&(r[n2]), &(a[n]), &(b[n]),
+                                  i, tna - i, tnb - i, p);
+            memset(&(r[n2 + tna + tnb]), 0,
+                   sizeof(BN_ULONG) * (n2 - tna - tnb));
+        } else {                /* (j < 0) eg, n == 16, i == 8 and tn == 5 */
+
+            memset(&(r[n2]), 0, sizeof(BN_ULONG) * n2);
+            if (tna < BN_MUL_RECURSIVE_SIZE_NORMAL
+                && tnb < BN_MUL_RECURSIVE_SIZE_NORMAL) {
+                bn_mul_normal(&(r[n2]), &(a[n]), tna, &(b[n]), tnb);
+            } else {
+                for (;;) {
+                    i /= 2;
+                    /*
+                     * these simplified conditions work exclusively because
+                     * difference between tna and tnb is 1 or 0
+                     */
+                    if (i < tna || i < tnb) {
+                        bn_mul_part_recursive(&(r[n2]),
+                                              &(a[n]), &(b[n]),
+                                              i, tna - i, tnb - i, p);
+                        break;
+                    } else if (i == tna || i == tnb) {
+                        bn_mul_recursive(&(r[n2]),
+                                         &(a[n]), &(b[n]),
+                                         i, tna - i, tnb - i, p);
+                        break;
+                    }
+                }
+            }
+        }
+    }
+
+    /*-
+     * t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign
+     * r[10] holds (a[0]*b[0])
+     * r[32] holds (b[1]*b[1])
+     */
+
+    c1 = (int)(bn_add_words(t, r, &(r[n2]), n2));
+
+    if (neg) {                  /* if t[32] is negative */
+        c1 -= (int)(bn_sub_words(&(t[n2]), t, &(t[n2]), n2));
+    } else {
+        /* Might have a carry */
+        c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), t, n2));
+    }
+
+    /*-
+     * t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1])
+     * r[10] holds (a[0]*b[0])
+     * r[32] holds (b[1]*b[1])
+     * c1 holds the carry bits
+     */
+    c1 += (int)(bn_add_words(&(r[n]), &(r[n]), &(t[n2]), n2));
+    if (c1) {
+        p = &(r[n + n2]);
+        lo = *p;
+        ln = (lo + c1) & BN_MASK2;
+        *p = ln;
+
+        /*
+         * The overflow will stop before we over write words we should not
+         * overwrite
+         */
+        if (ln < (BN_ULONG)c1) {
+            do {
+                p++;
+                lo = *p;
+                ln = (lo + 1) & BN_MASK2;
+                *p = ln;
+            } while (ln == 0);
+        }
+    }
+}
+
+/*-
+ * a and b must be the same size, which is n2.
+ * r needs to be n2 words and t needs to be n2*2
+ */
+void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
+                          BN_ULONG *t)
+{
+    int n = n2 / 2;
+
+# ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_low_recursive %d * %d\n", n2, n2);
+# endif
+
+    bn_mul_recursive(r, a, b, n, 0, 0, &(t[0]));
+    if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL) {
+        bn_mul_low_recursive(&(t[0]), &(a[0]), &(b[n]), n, &(t[n2]));
+        bn_add_words(&(r[n]), &(r[n]), &(t[0]), n);
+        bn_mul_low_recursive(&(t[0]), &(a[n]), &(b[0]), n, &(t[n2]));
+        bn_add_words(&(r[n]), &(r[n]), &(t[0]), n);
+    } else {
+        bn_mul_low_normal(&(t[0]), &(a[0]), &(b[n]), n);
+        bn_mul_low_normal(&(t[n]), &(a[n]), &(b[0]), n);
+        bn_add_words(&(r[n]), &(r[n]), &(t[0]), n);
+        bn_add_words(&(r[n]), &(r[n]), &(t[n]), n);
+    }
+}
+
+/*-
+ * a and b must be the same size, which is n2.
+ * r needs to be n2 words and t needs to be n2*2
+ * l is the low words of the output.
+ * t needs to be n2*3
+ */
+void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,
+                 BN_ULONG *t)
+{
+    int i, n;
+    int c1, c2;
+    int neg, oneg, zero;
+    BN_ULONG ll, lc, *lp, *mp;
+
+# ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_high %d * %d\n", n2, n2);
+# endif
+    n = n2 / 2;
+
+    /* Calculate (al-ah)*(bh-bl) */
+    neg = zero = 0;
+    c1 = bn_cmp_words(&(a[0]), &(a[n]), n);
+    c2 = bn_cmp_words(&(b[n]), &(b[0]), n);
+    switch (c1 * 3 + c2) {
+    case -4:
+        bn_sub_words(&(r[0]), &(a[n]), &(a[0]), n);
+        bn_sub_words(&(r[n]), &(b[0]), &(b[n]), n);
+        break;
+    case -3:
+        zero = 1;
+        break;
+    case -2:
+        bn_sub_words(&(r[0]), &(a[n]), &(a[0]), n);
+        bn_sub_words(&(r[n]), &(b[n]), &(b[0]), n);
+        neg = 1;
+        break;
+    case -1:
+    case 0:
+    case 1:
+        zero = 1;
+        break;
+    case 2:
+        bn_sub_words(&(r[0]), &(a[0]), &(a[n]), n);
+        bn_sub_words(&(r[n]), &(b[0]), &(b[n]), n);
+        neg = 1;
+        break;
+    case 3:
+        zero = 1;
+        break;
+    case 4:
+        bn_sub_words(&(r[0]), &(a[0]), &(a[n]), n);
+        bn_sub_words(&(r[n]), &(b[n]), &(b[0]), n);
+        break;
+    }
+
+    oneg = neg;
+    /* t[10] = (a[0]-a[1])*(b[1]-b[0]) */
+    /* r[10] = (a[1]*b[1]) */
+# ifdef BN_MUL_COMBA
+    if (n == 8) {
+        bn_mul_comba8(&(t[0]), &(r[0]), &(r[n]));
+        bn_mul_comba8(r, &(a[n]), &(b[n]));
+    } else
+# endif
+    {
+        bn_mul_recursive(&(t[0]), &(r[0]), &(r[n]), n, 0, 0, &(t[n2]));
+        bn_mul_recursive(r, &(a[n]), &(b[n]), n, 0, 0, &(t[n2]));
+    }
+
+    /*-
+     * s0 == low(al*bl)
+     * s1 == low(ah*bh)+low((al-ah)*(bh-bl))+low(al*bl)+high(al*bl)
+     * We know s0 and s1 so the only unknown is high(al*bl)
+     * high(al*bl) == s1 - low(ah*bh+s0+(al-ah)*(bh-bl))
+     * high(al*bl) == s1 - (r[0]+l[0]+t[0])
+     */
+    if (l != NULL) {
+        lp = &(t[n2 + n]);
+        c1 = (int)(bn_add_words(lp, &(r[0]), &(l[0]), n));
+    } else {
+        c1 = 0;
+        lp = &(r[0]);
+    }
+
+    if (neg)
+        neg = (int)(bn_sub_words(&(t[n2]), lp, &(t[0]), n));
+    else {
+        bn_add_words(&(t[n2]), lp, &(t[0]), n);
+        neg = 0;
+    }
+
+    if (l != NULL) {
+        bn_sub_words(&(t[n2 + n]), &(l[n]), &(t[n2]), n);
+    } else {
+        lp = &(t[n2 + n]);
+        mp = &(t[n2]);
+        for (i = 0; i < n; i++)
+            lp[i] = ((~mp[i]) + 1) & BN_MASK2;
+    }
+
+    /*-
+     * s[0] = low(al*bl)
+     * t[3] = high(al*bl)
+     * t[10] = (a[0]-a[1])*(b[1]-b[0]) neg is the sign
+     * r[10] = (a[1]*b[1])
+     */
+    /*-
+     * R[10] = al*bl
+     * R[21] = al*bl + ah*bh + (a[0]-a[1])*(b[1]-b[0])
+     * R[32] = ah*bh
+     */
+    /*-
+     * R[1]=t[3]+l[0]+r[0](+-)t[0] (have carry/borrow)
+     * R[2]=r[0]+t[3]+r[1](+-)t[1] (have carry/borrow)
+     * R[3]=r[1]+(carry/borrow)
+     */
+    if (l != NULL) {
+        lp = &(t[n2]);
+        c1 = (int)(bn_add_words(lp, &(t[n2 + n]), &(l[0]), n));
+    } else {
+        lp = &(t[n2 + n]);
+        c1 = 0;
+    }
+    c1 += (int)(bn_add_words(&(t[n2]), lp, &(r[0]), n));
+    if (oneg)
+        c1 -= (int)(bn_sub_words(&(t[n2]), &(t[n2]), &(t[0]), n));
+    else
+        c1 += (int)(bn_add_words(&(t[n2]), &(t[n2]), &(t[0]), n));
+
+    c2 = (int)(bn_add_words(&(r[0]), &(r[0]), &(t[n2 + n]), n));
+    c2 += (int)(bn_add_words(&(r[0]), &(r[0]), &(r[n]), n));
+    if (oneg)
+        c2 -= (int)(bn_sub_words(&(r[0]), &(r[0]), &(t[n]), n));
+    else
+        c2 += (int)(bn_add_words(&(r[0]), &(r[0]), &(t[n]), n));
+
+    if (c1 != 0) {              /* Add starting at r[0], could be +ve or -ve */
+        i = 0;
+        if (c1 > 0) {
+            lc = c1;
+            do {
+                ll = (r[i] + lc) & BN_MASK2;
+                r[i++] = ll;
+                lc = (lc > ll);
+            } while (lc);
+        } else {
+            lc = -c1;
+            do {
+                ll = r[i];
+                r[i++] = (ll - lc) & BN_MASK2;
+                lc = (lc > ll);
+            } while (lc);
+        }
+    }
+    if (c2 != 0) {              /* Add starting at r[1] */
+        i = n;
+        if (c2 > 0) {
+            lc = c2;
+            do {
+                ll = (r[i] + lc) & BN_MASK2;
+                r[i++] = ll;
+                lc = (lc > ll);
+            } while (lc);
+        } else {
+            lc = -c2;
+            do {
+                ll = r[i];
+                r[i++] = (ll - lc) & BN_MASK2;
+                lc = (lc > ll);
+            } while (lc);
+        }
+    }
+}
+#endif                          /* BN_RECURSION */
+
+int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
+{
+    int ret = 0;
+    int top, al, bl;
+    BIGNUM *rr;
+#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
+    int i;
+#endif
+#ifdef BN_RECURSION
+    BIGNUM *t = NULL;
+    int j = 0, k;
+#endif
+
+#ifdef BN_COUNT
+    fprintf(stderr, "BN_mul %d * %d\n", a->top, b->top);
+#endif
+
+    bn_check_top(a);
+    bn_check_top(b);
+    bn_check_top(r);
+
+    al = a->top;
+    bl = b->top;
+
+    if ((al == 0) || (bl == 0)) {
+        BN_zero(r);
+        return (1);
+    }
+    top = al + bl;
+
+    BN_CTX_start(ctx);
+    if ((r == a) || (r == b)) {
+        if ((rr = BN_CTX_get(ctx)) == NULL)
+            goto err;
+    } else
+        rr = r;
+    rr->neg = a->neg ^ b->neg;
+
+#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
+    i = al - bl;
+#endif
+#ifdef BN_MUL_COMBA
+    if (i == 0) {
+# if 0
+        if (al == 4) {
+            if (bn_wexpand(rr, 8) == NULL)
+                goto err;
+            rr->top = 8;
+            bn_mul_comba4(rr->d, a->d, b->d);
+            goto end;
+        }
+# endif
+        if (al == 8) {
+            if (bn_wexpand(rr, 16) == NULL)
+                goto err;
+            rr->top = 16;
+            bn_mul_comba8(rr->d, a->d, b->d);
+            goto end;
+        }
+    }
+#endif                          /* BN_MUL_COMBA */
+#ifdef BN_RECURSION
+    if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL)) {
+        if (i >= -1 && i <= 1) {
+            /*
+             * Find out the power of two lower or equal to the longest of the
+             * two numbers
+             */
+            if (i >= 0) {
+                j = BN_num_bits_word((BN_ULONG)al);
+            }
+            if (i == -1) {
+                j = BN_num_bits_word((BN_ULONG)bl);
+            }
+            j = 1 << (j - 1);
+            assert(j <= al || j <= bl);
+            k = j + j;
+            t = BN_CTX_get(ctx);
+            if (t == NULL)
+                goto err;
+            if (al > j || bl > j) {
+                if (bn_wexpand(t, k * 4) == NULL)
+                    goto err;
+                if (bn_wexpand(rr, k * 4) == NULL)
+                    goto err;
+                bn_mul_part_recursive(rr->d, a->d, b->d,
+                                      j, al - j, bl - j, t->d);
+            } else {            /* al <= j || bl <= j */
+
+                if (bn_wexpand(t, k * 2) == NULL)
+                    goto err;
+                if (bn_wexpand(rr, k * 2) == NULL)
+                    goto err;
+                bn_mul_recursive(rr->d, a->d, b->d, j, al - j, bl - j, t->d);
+            }
+            rr->top = top;
+            goto end;
+        }
+# if 0
+        if (i == 1 && !BN_get_flags(b, BN_FLG_STATIC_DATA)) {
+            BIGNUM *tmp_bn = (BIGNUM *)b;
+            if (bn_wexpand(tmp_bn, al) == NULL)
+                goto err;
+            tmp_bn->d[bl] = 0;
+            bl++;
+            i--;
+        } else if (i == -1 && !BN_get_flags(a, BN_FLG_STATIC_DATA)) {
+            BIGNUM *tmp_bn = (BIGNUM *)a;
+            if (bn_wexpand(tmp_bn, bl) == NULL)
+                goto err;
+            tmp_bn->d[al] = 0;
+            al++;
+            i++;
+        }
+        if (i == 0) {
+            /* symmetric and > 4 */
+            /* 16 or larger */
+            j = BN_num_bits_word((BN_ULONG)al);
+            j = 1 << (j - 1);
+            k = j + j;
+            t = BN_CTX_get(ctx);
+            if (al == j) {      /* exact multiple */
+                if (bn_wexpand(t, k * 2) == NULL)
+                    goto err;
+                if (bn_wexpand(rr, k * 2) == NULL)
+                    goto err;
+                bn_mul_recursive(rr->d, a->d, b->d, al, t->d);
+            } else {
+                if (bn_wexpand(t, k * 4) == NULL)
+                    goto err;
+                if (bn_wexpand(rr, k * 4) == NULL)
+                    goto err;
+                bn_mul_part_recursive(rr->d, a->d, b->d, al - j, j, t->d);
+            }
+            rr->top = top;
+            goto end;
+        }
+# endif
+    }
+#endif                          /* BN_RECURSION */
+    if (bn_wexpand(rr, top) == NULL)
+        goto err;
+    rr->top = top;
+    bn_mul_normal(rr->d, a->d, al, b->d, bl);
+
+#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)
+ end:
+#endif
+    bn_correct_top(rr);
+    if (r != rr)
+        BN_copy(r, rr);
+    ret = 1;
+ err:
+    bn_check_top(r);
+    BN_CTX_end(ctx);
+    return (ret);
+}
+
+void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb)
+{
+    BN_ULONG *rr;
+
+#ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_normal %d * %d\n", na, nb);
+#endif
+
+    if (na < nb) {
+        int itmp;
+        BN_ULONG *ltmp;
+
+        itmp = na;
+        na = nb;
+        nb = itmp;
+        ltmp = a;
+        a = b;
+        b = ltmp;
+
+    }
+    rr = &(r[na]);
+    if (nb <= 0) {
+        (void)bn_mul_words(r, a, na, 0);
+        return;
+    } else
+        rr[0] = bn_mul_words(r, a, na, b[0]);
+
+    for (;;) {
+        if (--nb <= 0)
+            return;
+        rr[1] = bn_mul_add_words(&(r[1]), a, na, b[1]);
+        if (--nb <= 0)
+            return;
+        rr[2] = bn_mul_add_words(&(r[2]), a, na, b[2]);
+        if (--nb <= 0)
+            return;
+        rr[3] = bn_mul_add_words(&(r[3]), a, na, b[3]);
+        if (--nb <= 0)
+            return;
+        rr[4] = bn_mul_add_words(&(r[4]), a, na, b[4]);
+        rr += 4;
+        r += 4;
+        b += 4;
+    }
+}
+
+void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
+{
+#ifdef BN_COUNT
+    fprintf(stderr, " bn_mul_low_normal %d * %d\n", n, n);
+#endif
+    bn_mul_words(r, a, n, b[0]);
+
+    for (;;) {
+        if (--n <= 0)
+            return;
+        bn_mul_add_words(&(r[1]), a, n, b[1]);
+        if (--n <= 0)
+            return;
+        bn_mul_add_words(&(r[2]), a, n, b[2]);
+        if (--n <= 0)
+            return;
+        bn_mul_add_words(&(r[3]), a, n, b[3]);
+        if (--n <= 0)
+            return;
+        bn_mul_add_words(&(r[4]), a, n, b[4]);
+        r += 4;
+        b += 4;
+    }
+}