openssl: Move to a module and split thirdparty lib

Same rationale as the previous commits.

1 files changed, 916 insertions, 0 deletions

diff --git a/thirdparty/openssl/crypto/bn/bn_lib.c b/thirdparty/openssl/crypto/bn/bn_lib.c
new file mode 100644
index 0000000000..80105fff41
--- /dev/null
+++ b/thirdparty/openssl/crypto/bn/bn_lib.c
@@ -0,0 +1,916 @@
+/* crypto/bn/bn_lib.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 <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include "cryptlib.h"
+#include "bn_lcl.h"
+
+const char BN_version[] = "Big Number" OPENSSL_VERSION_PTEXT;
+
+/* This stuff appears to be completely unused, so is deprecated */
+#ifndef OPENSSL_NO_DEPRECATED
+/*-
+ * For a 32 bit machine
+ * 2 -   4 ==  128
+ * 3 -   8 ==  256
+ * 4 -  16 ==  512
+ * 5 -  32 == 1024
+ * 6 -  64 == 2048
+ * 7 - 128 == 4096
+ * 8 - 256 == 8192
+ */
+static int bn_limit_bits = 0;
+static int bn_limit_num = 8;    /* (1<<bn_limit_bits) */
+static int bn_limit_bits_low = 0;
+static int bn_limit_num_low = 8; /* (1<<bn_limit_bits_low) */
+static int bn_limit_bits_high = 0;
+static int bn_limit_num_high = 8; /* (1<<bn_limit_bits_high) */
+static int bn_limit_bits_mont = 0;
+static int bn_limit_num_mont = 8; /* (1<<bn_limit_bits_mont) */
+
+void BN_set_params(int mult, int high, int low, int mont)
+{
+    if (mult >= 0) {
+        if (mult > (int)(sizeof(int) * 8) - 1)
+            mult = sizeof(int) * 8 - 1;
+        bn_limit_bits = mult;
+        bn_limit_num = 1 << mult;
+    }
+    if (high >= 0) {
+        if (high > (int)(sizeof(int) * 8) - 1)
+            high = sizeof(int) * 8 - 1;
+        bn_limit_bits_high = high;
+        bn_limit_num_high = 1 << high;
+    }
+    if (low >= 0) {
+        if (low > (int)(sizeof(int) * 8) - 1)
+            low = sizeof(int) * 8 - 1;
+        bn_limit_bits_low = low;
+        bn_limit_num_low = 1 << low;
+    }
+    if (mont >= 0) {
+        if (mont > (int)(sizeof(int) * 8) - 1)
+            mont = sizeof(int) * 8 - 1;
+        bn_limit_bits_mont = mont;
+        bn_limit_num_mont = 1 << mont;
+    }
+}
+
+int BN_get_params(int which)
+{
+    if (which == 0)
+        return (bn_limit_bits);
+    else if (which == 1)
+        return (bn_limit_bits_high);
+    else if (which == 2)
+        return (bn_limit_bits_low);
+    else if (which == 3)
+        return (bn_limit_bits_mont);
+    else
+        return (0);
+}
+#endif
+
+const BIGNUM *BN_value_one(void)
+{
+    static const BN_ULONG data_one = 1L;
+    static const BIGNUM const_one =
+        { (BN_ULONG *)&data_one, 1, 1, 0, BN_FLG_STATIC_DATA };
+
+    return (&const_one);
+}
+
+int BN_num_bits_word(BN_ULONG l)
+{
+    static const unsigned char bits[256] = {
+        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,
+    };
+
+#if defined(SIXTY_FOUR_BIT_LONG)
+    if (l & 0xffffffff00000000L) {
+        if (l & 0xffff000000000000L) {
+            if (l & 0xff00000000000000L) {
+                return (bits[(int)(l >> 56)] + 56);
+            } else
+                return (bits[(int)(l >> 48)] + 48);
+        } else {
+            if (l & 0x0000ff0000000000L) {
+                return (bits[(int)(l >> 40)] + 40);
+            } else
+                return (bits[(int)(l >> 32)] + 32);
+        }
+    } else
+#else
+# ifdef SIXTY_FOUR_BIT
+    if (l & 0xffffffff00000000LL) {
+        if (l & 0xffff000000000000LL) {
+            if (l & 0xff00000000000000LL) {
+                return (bits[(int)(l >> 56)] + 56);
+            } else
+                return (bits[(int)(l >> 48)] + 48);
+        } else {
+            if (l & 0x0000ff0000000000LL) {
+                return (bits[(int)(l >> 40)] + 40);
+            } else
+                return (bits[(int)(l >> 32)] + 32);
+        }
+    } else
+# endif
+#endif
+    {
+#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
+        if (l & 0xffff0000L) {
+            if (l & 0xff000000L)
+                return (bits[(int)(l >> 24L)] + 24);
+            else
+                return (bits[(int)(l >> 16L)] + 16);
+        } else
+#endif
+        {
+#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
+            if (l & 0xff00L)
+                return (bits[(int)(l >> 8)] + 8);
+            else
+#endif
+                return (bits[(int)(l)]);
+        }
+    }
+}
+
+int BN_num_bits(const BIGNUM *a)
+{
+    int i = a->top - 1;
+    bn_check_top(a);
+
+    if (BN_is_zero(a))
+        return 0;
+    return ((i * BN_BITS2) + BN_num_bits_word(a->d[i]));
+}
+
+void BN_clear_free(BIGNUM *a)
+{
+    int i;
+
+    if (a == NULL)
+        return;
+    bn_check_top(a);
+    if (a->d != NULL) {
+        OPENSSL_cleanse(a->d, a->dmax * sizeof(a->d[0]));
+        if (!(BN_get_flags(a, BN_FLG_STATIC_DATA)))
+            OPENSSL_free(a->d);
+    }
+    i = BN_get_flags(a, BN_FLG_MALLOCED);
+    OPENSSL_cleanse(a, sizeof(BIGNUM));
+    if (i)
+        OPENSSL_free(a);
+}
+
+void BN_free(BIGNUM *a)
+{
+    if (a == NULL)
+        return;
+    bn_check_top(a);
+    if ((a->d != NULL) && !(BN_get_flags(a, BN_FLG_STATIC_DATA)))
+        OPENSSL_free(a->d);
+    if (a->flags & BN_FLG_MALLOCED)
+        OPENSSL_free(a);
+    else {
+#ifndef OPENSSL_NO_DEPRECATED
+        a->flags |= BN_FLG_FREE;
+#endif
+        a->d = NULL;
+    }
+}
+
+void BN_init(BIGNUM *a)
+{
+    memset(a, 0, sizeof(BIGNUM));
+    bn_check_top(a);
+}
+
+BIGNUM *BN_new(void)
+{
+    BIGNUM *ret;
+
+    if ((ret = (BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL) {
+        BNerr(BN_F_BN_NEW, ERR_R_MALLOC_FAILURE);
+        return (NULL);
+    }
+    ret->flags = BN_FLG_MALLOCED;
+    ret->top = 0;
+    ret->neg = 0;
+    ret->dmax = 0;
+    ret->d = NULL;
+    bn_check_top(ret);
+    return (ret);
+}
+
+/* This is used both by bn_expand2() and bn_dup_expand() */
+/* The caller MUST check that words > b->dmax before calling this */
+static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
+{
+    BN_ULONG *A, *a = NULL;
+    const BN_ULONG *B;
+    int i;
+
+    bn_check_top(b);
+
+    if (words > (INT_MAX / (4 * BN_BITS2))) {
+        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);
+        return NULL;
+    }
+    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {
+        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
+        return (NULL);
+    }
+    a = A = (BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG) * words);
+    if (A == NULL) {
+        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);
+        return (NULL);
+    }
+#ifdef PURIFY
+    /*
+     * Valgrind complains in BN_consttime_swap because we process the whole
+     * array even if it's not initialised yet. This doesn't matter in that
+     * function - what's important is constant time operation (we're not
+     * actually going to use the data)
+     */
+    memset(a, 0, sizeof(BN_ULONG) * words);
+#endif
+
+#if 1
+    B = b->d;
+    /* Check if the previous number needs to be copied */
+    if (B != NULL) {
+        for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) {
+            /*
+             * The fact that the loop is unrolled
+             * 4-wise is a tribute to Intel. It's
+             * the one that doesn't have enough
+             * registers to accomodate more data.
+             * I'd unroll it 8-wise otherwise:-)
+             *
+             *              <appro@fy.chalmers.se>
+             */
+            BN_ULONG a0, a1, a2, a3;
+            a0 = B[0];
+            a1 = B[1];
+            a2 = B[2];
+            a3 = B[3];
+            A[0] = a0;
+            A[1] = a1;
+            A[2] = a2;
+            A[3] = a3;
+        }
+        /*
+         * workaround for ultrix cc: without 'case 0', the optimizer does
+         * the switch table by doing a=top&3; a--; goto jump_table[a];
+         * which fails for top== 0
+         */
+        switch (b->top & 3) {
+        case 3:
+            A[2] = B[2];
+        case 2:
+            A[1] = B[1];
+        case 1:
+            A[0] = B[0];
+        case 0:
+            ;
+        }
+    }
+#else
+    memset(A, 0, sizeof(BN_ULONG) * words);
+    memcpy(A, b->d, sizeof(b->d[0]) * b->top);
+#endif
+
+    return (a);
+}
+
+/*
+ * This is an internal function that can be used instead of bn_expand2() when
+ * there is a need to copy BIGNUMs instead of only expanding the data part,
+ * while still expanding them. Especially useful when needing to expand
+ * BIGNUMs that are declared 'const' and should therefore not be changed. The
+ * reason to use this instead of a BN_dup() followed by a bn_expand2() is
+ * memory allocation overhead.  A BN_dup() followed by a bn_expand2() will
+ * allocate new memory for the BIGNUM data twice, and free it once, while
+ * bn_dup_expand() makes sure allocation is made only once.
+ */
+
+#ifndef OPENSSL_NO_DEPRECATED
+BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
+{
+    BIGNUM *r = NULL;
+
+    bn_check_top(b);
+
+    /*
+     * This function does not work if words <= b->dmax && top < words because
+     * BN_dup() does not preserve 'dmax'! (But bn_dup_expand() is not used
+     * anywhere yet.)
+     */
+
+    if (words > b->dmax) {
+        BN_ULONG *a = bn_expand_internal(b, words);
+
+        if (a) {
+            r = BN_new();
+            if (r) {
+                r->top = b->top;
+                r->dmax = words;
+                r->neg = b->neg;
+                r->d = a;
+            } else {
+                /* r == NULL, BN_new failure */
+                OPENSSL_free(a);
+            }
+        }
+        /*
+         * If a == NULL, there was an error in allocation in
+         * bn_expand_internal(), and NULL should be returned
+         */
+    } else {
+        r = BN_dup(b);
+    }
+
+    bn_check_top(r);
+    return r;
+}
+#endif
+
+/*
+ * This is an internal function that should not be used in applications. It
+ * ensures that 'b' has enough room for a 'words' word number and initialises
+ * any unused part of b->d with leading zeros. It is mostly used by the
+ * various BIGNUM routines. If there is an error, NULL is returned. If not,
+ * 'b' is returned.
+ */
+
+BIGNUM *bn_expand2(BIGNUM *b, int words)
+{
+    bn_check_top(b);
+
+    if (words > b->dmax) {
+        BN_ULONG *a = bn_expand_internal(b, words);
+        if (!a)
+            return NULL;
+        if (b->d)
+            OPENSSL_free(b->d);
+        b->d = a;
+        b->dmax = words;
+    }
+
+/* None of this should be necessary because of what b->top means! */
+#if 0
+    /*
+     * NB: bn_wexpand() calls this only if the BIGNUM really has to grow
+     */
+    if (b->top < b->dmax) {
+        int i;
+        BN_ULONG *A = &(b->d[b->top]);
+        for (i = (b->dmax - b->top) >> 3; i > 0; i--, A += 8) {
+            A[0] = 0;
+            A[1] = 0;
+            A[2] = 0;
+            A[3] = 0;
+            A[4] = 0;
+            A[5] = 0;
+            A[6] = 0;
+            A[7] = 0;
+        }
+        for (i = (b->dmax - b->top) & 7; i > 0; i--, A++)
+            A[0] = 0;
+        assert(A == &(b->d[b->dmax]));
+    }
+#endif
+    bn_check_top(b);
+    return b;
+}
+
+BIGNUM *BN_dup(const BIGNUM *a)
+{
+    BIGNUM *t;
+
+    if (a == NULL)
+        return NULL;
+    bn_check_top(a);
+
+    t = BN_new();
+    if (t == NULL)
+        return NULL;
+    if (!BN_copy(t, a)) {
+        BN_free(t);
+        return NULL;
+    }
+    bn_check_top(t);
+    return t;
+}
+
+BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
+{
+    int i;
+    BN_ULONG *A;
+    const BN_ULONG *B;
+
+    bn_check_top(b);
+
+    if (a == b)
+        return (a);
+    if (bn_wexpand(a, b->top) == NULL)
+        return (NULL);
+
+#if 1
+    A = a->d;
+    B = b->d;
+    for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) {
+        BN_ULONG a0, a1, a2, a3;
+        a0 = B[0];
+        a1 = B[1];
+        a2 = B[2];
+        a3 = B[3];
+        A[0] = a0;
+        A[1] = a1;
+        A[2] = a2;
+        A[3] = a3;
+    }
+    /* ultrix cc workaround, see comments in bn_expand_internal */
+    switch (b->top & 3) {
+    case 3:
+        A[2] = B[2];
+    case 2:
+        A[1] = B[1];
+    case 1:
+        A[0] = B[0];
+    case 0:;
+    }
+#else
+    memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
+#endif
+
+    a->top = b->top;
+    a->neg = b->neg;
+    bn_check_top(a);
+    return (a);
+}
+
+void BN_swap(BIGNUM *a, BIGNUM *b)
+{
+    int flags_old_a, flags_old_b;
+    BN_ULONG *tmp_d;
+    int tmp_top, tmp_dmax, tmp_neg;
+
+    bn_check_top(a);
+    bn_check_top(b);
+
+    flags_old_a = a->flags;
+    flags_old_b = b->flags;
+
+    tmp_d = a->d;
+    tmp_top = a->top;
+    tmp_dmax = a->dmax;
+    tmp_neg = a->neg;
+
+    a->d = b->d;
+    a->top = b->top;
+    a->dmax = b->dmax;
+    a->neg = b->neg;
+
+    b->d = tmp_d;
+    b->top = tmp_top;
+    b->dmax = tmp_dmax;
+    b->neg = tmp_neg;
+
+    a->flags =
+        (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA);
+    b->flags =
+        (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA);
+    bn_check_top(a);
+    bn_check_top(b);
+}
+
+void BN_clear(BIGNUM *a)
+{
+    bn_check_top(a);
+    if (a->d != NULL)
+        memset(a->d, 0, a->dmax * sizeof(a->d[0]));
+    a->top = 0;
+    a->neg = 0;
+}
+
+BN_ULONG BN_get_word(const BIGNUM *a)
+{
+    if (a->top > 1)
+        return BN_MASK2;
+    else if (a->top == 1)
+        return a->d[0];
+    /* a->top == 0 */
+    return 0;
+}
+
+int BN_set_word(BIGNUM *a, BN_ULONG w)
+{
+    bn_check_top(a);
+    if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL)
+        return (0);
+    a->neg = 0;
+    a->d[0] = w;
+    a->top = (w ? 1 : 0);
+    bn_check_top(a);
+    return (1);
+}
+
+BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
+{
+    unsigned int i, m;
+    unsigned int n;
+    BN_ULONG l;
+    BIGNUM *bn = NULL;
+
+    if (ret == NULL)
+        ret = bn = BN_new();
+    if (ret == NULL)
+        return (NULL);
+    bn_check_top(ret);
+    l = 0;
+    n = len;
+    if (n == 0) {
+        ret->top = 0;
+        return (ret);
+    }
+    i = ((n - 1) / BN_BYTES) + 1;
+    m = ((n - 1) % (BN_BYTES));
+    if (bn_wexpand(ret, (int)i) == NULL) {
+        if (bn)
+            BN_free(bn);
+        return NULL;
+    }
+    ret->top = i;
+    ret->neg = 0;
+    while (n--) {
+        l = (l << 8L) | *(s++);
+        if (m-- == 0) {
+            ret->d[--i] = l;
+            l = 0;
+            m = BN_BYTES - 1;
+        }
+    }
+    /*
+     * need to call this due to clear byte at top if avoiding having the top
+     * bit set (-ve number)
+     */
+    bn_correct_top(ret);
+    return (ret);
+}
+
+/* ignore negative */
+int BN_bn2bin(const BIGNUM *a, unsigned char *to)
+{
+    int n, i;
+    BN_ULONG l;
+
+    bn_check_top(a);
+    n = i = BN_num_bytes(a);
+    while (i--) {
+        l = a->d[i / BN_BYTES];
+        *(to++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff;
+    }
+    return (n);
+}
+
+int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
+{
+    int i;
+    BN_ULONG t1, t2, *ap, *bp;
+
+    bn_check_top(a);
+    bn_check_top(b);
+
+    i = a->top - b->top;
+    if (i != 0)
+        return (i);
+    ap = a->d;
+    bp = b->d;
+    for (i = a->top - 1; i >= 0; i--) {
+        t1 = ap[i];
+        t2 = bp[i];
+        if (t1 != t2)
+            return ((t1 > t2) ? 1 : -1);
+    }
+    return (0);
+}
+
+int BN_cmp(const BIGNUM *a, const BIGNUM *b)
+{
+    int i;
+    int gt, lt;
+    BN_ULONG t1, t2;
+
+    if ((a == NULL) || (b == NULL)) {
+        if (a != NULL)
+            return (-1);
+        else if (b != NULL)
+            return (1);
+        else
+            return (0);
+    }
+
+    bn_check_top(a);
+    bn_check_top(b);
+
+    if (a->neg != b->neg) {
+        if (a->neg)
+            return (-1);
+        else
+            return (1);
+    }
+    if (a->neg == 0) {
+        gt = 1;
+        lt = -1;
+    } else {
+        gt = -1;
+        lt = 1;
+    }
+
+    if (a->top > b->top)
+        return (gt);
+    if (a->top < b->top)
+        return (lt);
+    for (i = a->top - 1; i >= 0; i--) {
+        t1 = a->d[i];
+        t2 = b->d[i];
+        if (t1 > t2)
+            return (gt);
+        if (t1 < t2)
+            return (lt);
+    }
+    return (0);
+}
+
+int BN_set_bit(BIGNUM *a, int n)
+{
+    int i, j, k;
+
+    if (n < 0)
+        return 0;
+
+    i = n / BN_BITS2;
+    j = n % BN_BITS2;
+    if (a->top <= i) {
+        if (bn_wexpand(a, i + 1) == NULL)
+            return (0);
+        for (k = a->top; k < i + 1; k++)
+            a->d[k] = 0;
+        a->top = i + 1;
+    }
+
+    a->d[i] |= (((BN_ULONG)1) << j);
+    bn_check_top(a);
+    return (1);
+}
+
+int BN_clear_bit(BIGNUM *a, int n)
+{
+    int i, j;
+
+    bn_check_top(a);
+    if (n < 0)
+        return 0;
+
+    i = n / BN_BITS2;
+    j = n % BN_BITS2;
+    if (a->top <= i)
+        return (0);
+
+    a->d[i] &= (~(((BN_ULONG)1) << j));
+    bn_correct_top(a);
+    return (1);
+}
+
+int BN_is_bit_set(const BIGNUM *a, int n)
+{
+    int i, j;
+
+    bn_check_top(a);
+    if (n < 0)
+        return 0;
+    i = n / BN_BITS2;
+    j = n % BN_BITS2;
+    if (a->top <= i)
+        return 0;
+    return (int)(((a->d[i]) >> j) & ((BN_ULONG)1));
+}
+
+int BN_mask_bits(BIGNUM *a, int n)
+{
+    int b, w;
+
+    bn_check_top(a);
+    if (n < 0)
+        return 0;
+
+    w = n / BN_BITS2;
+    b = n % BN_BITS2;
+    if (w >= a->top)
+        return 0;
+    if (b == 0)
+        a->top = w;
+    else {
+        a->top = w + 1;
+        a->d[w] &= ~(BN_MASK2 << b);
+    }
+    bn_correct_top(a);
+    return (1);
+}
+
+void BN_set_negative(BIGNUM *a, int b)
+{
+    if (b && !BN_is_zero(a))
+        a->neg = 1;
+    else
+        a->neg = 0;
+}
+
+int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n)
+{
+    int i;
+    BN_ULONG aa, bb;
+
+    aa = a[n - 1];
+    bb = b[n - 1];
+    if (aa != bb)
+        return ((aa > bb) ? 1 : -1);
+    for (i = n - 2; i >= 0; i--) {
+        aa = a[i];
+        bb = b[i];
+        if (aa != bb)
+            return ((aa > bb) ? 1 : -1);
+    }
+    return (0);
+}
+
+/*
+ * Here follows a specialised variants of bn_cmp_words().  It has the
+ * property of performing the operation 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...
+ */
+
+int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl)
+{
+    int n, i;
+    n = cl - 1;
+
+    if (dl < 0) {
+        for (i = dl; i < 0; i++) {
+            if (b[n - i] != 0)
+                return -1;      /* a < b */
+        }
+    }
+    if (dl > 0) {
+        for (i = dl; i > 0; i--) {
+            if (a[n + i] != 0)
+                return 1;       /* a > b */
+        }
+    }
+    return bn_cmp_words(a, b, cl);
+}
+
+/*
+ * Constant-time conditional swap of a and b.
+ * a and b are swapped if condition is not 0.  The code assumes that at most one bit of condition is set.
+ * nwords is the number of words to swap.  The code assumes that at least nwords are allocated in both a and b,
+ * and that no more than nwords are used by either a or b.
+ * a and b cannot be the same number
+ */
+void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords)
+{
+    BN_ULONG t;
+    int i;
+
+    bn_wcheck_size(a, nwords);
+    bn_wcheck_size(b, nwords);
+
+    assert(a != b);
+    assert((condition & (condition - 1)) == 0);
+    assert(sizeof(BN_ULONG) >= sizeof(int));
+
+    condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1;
+
+    t = (a->top ^ b->top) & condition;
+    a->top ^= t;
+    b->top ^= t;
+
+#define BN_CONSTTIME_SWAP(ind) \
+        do { \
+                t = (a->d[ind] ^ b->d[ind]) & condition; \
+                a->d[ind] ^= t; \
+                b->d[ind] ^= t; \
+        } while (0)
+
+    switch (nwords) {
+    default:
+        for (i = 10; i < nwords; i++)
+            BN_CONSTTIME_SWAP(i);
+        /* Fallthrough */
+    case 10:
+        BN_CONSTTIME_SWAP(9);   /* Fallthrough */
+    case 9:
+        BN_CONSTTIME_SWAP(8);   /* Fallthrough */
+    case 8:
+        BN_CONSTTIME_SWAP(7);   /* Fallthrough */
+    case 7:
+        BN_CONSTTIME_SWAP(6);   /* Fallthrough */
+    case 6:
+        BN_CONSTTIME_SWAP(5);   /* Fallthrough */
+    case 5:
+        BN_CONSTTIME_SWAP(4);   /* Fallthrough */
+    case 4:
+        BN_CONSTTIME_SWAP(3);   /* Fallthrough */
+    case 3:
+        BN_CONSTTIME_SWAP(2);   /* Fallthrough */
+    case 2:
+        BN_CONSTTIME_SWAP(1);   /* Fallthrough */
+    case 1:
+        BN_CONSTTIME_SWAP(0);
+    }
+#undef BN_CONSTTIME_SWAP
+}