1 files changed, 818 insertions, 0 deletions

diff --git a/src/lib/libcrypto/bn/bn_lib.c b/src/lib/libcrypto/bn/bn_lib.c
new file mode 100644
index 0000000000..a016cb7f53
--- /dev/null
+++ b/src/lib/libcrypto/bn/bn_lib.c
@@ -0,0 +1,818 @@
+/* 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;
+
+/* 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 > (sizeof(int)*8)-1)
+                        mult=sizeof(int)*8-1;
+                bn_limit_bits=mult;
+                bn_limit_num=1<<mult;
+                }
+        if (high >= 0)
+                {
+                if (high > (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 > (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 > (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);
+        }
+
+const BIGNUM *BN_value_one(void)
+        {
+        static BN_ULONG data_one=1L;
+        static BIGNUM const_one={&data_one,1,1,0};
+
+        return(&const_one);
+        }
+
+char *BN_options(void)
+        {
+        static int init=0;
+        static char data[16];
+
+        if (!init)
+                {
+                init++;
+#ifdef BN_LLONG
+                sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULLONG)*8,
+                        (int)sizeof(BN_ULONG)*8);
+#else
+                sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULONG)*8,
+                        (int)sizeof(BN_ULONG)*8);
+#endif
+                }
+        return(data);
+        }
+
+int BN_num_bits_word(BN_ULONG l)
+        {
+        static const 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(SIXTEEN_BIT) || 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)
+        {
+        BN_ULONG l;
+        int i;
+
+        bn_check_top(a);
+
+        if (a->top == 0) return(0);
+        l=a->d[a->top-1];
+        assert(l != 0);
+        i=(a->top-1)*BN_BITS2;
+        return(i+BN_num_bits_word(l));
+        }
+
+void BN_clear_free(BIGNUM *a)
+        {
+        int i;
+
+        if (a == NULL) return;
+        if (a->d != NULL)
+                {
+                memset(a->d,0,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);
+        memset(a,0,sizeof(BIGNUM));
+        if (i)
+                OPENSSL_free(a);
+        }
+
+void BN_free(BIGNUM *a)
+        {
+        if (a == NULL) return;
+        if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
+                OPENSSL_free(a->d);
+        a->flags|=BN_FLG_FREE; /* REMOVE? */
+        if (a->flags & BN_FLG_MALLOCED)
+                OPENSSL_free(a);
+        }
+
+void BN_init(BIGNUM *a)
+        {
+        memset(a,0,sizeof(BIGNUM));
+        }
+
+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;
+        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;
+
+        if (words > (INT_MAX/(4*BN_BITS2)))
+                {
+                BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG);
+                return NULL;
+                }
+
+        bn_check_top(b);        
+        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+1));
+        if (A == NULL)
+                {
+                BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE);
+                return(NULL);
+                }
+#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;
+                        }
+                switch (b->top&3)
+                        {
+                case 3: A[2]=B[2];
+                case 2: A[1]=B[1];
+                case 1: A[0]=B[0];
+                case 0: /* 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 */
+                        ;
+                        }
+                }
+
+        /* Now need to zero any data between b->top and b->max */
+        /* XXX Why? */
+
+        A= &(a[b->top]);
+        for (i=(words - 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=(words - b->top)&7; i>0; i--,A++)
+                A[0]=0;
+#else
+        memset(A,0,sizeof(BN_ULONG)*(words+1));
+        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.
+ */
+
+BIGNUM *bn_dup_expand(const BIGNUM *b, int words)
+        {
+        BIGNUM *r = NULL;
+
+        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);
+                }
+
+        return r;
+        }
+
+/* This is an internal function that should not be used in applications.
+ * It ensures that 'b' has enough room for a 'words' word number number.
+ * 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)
+        {
+        if (words > b->dmax)
+                {
+                BN_ULONG *a = bn_expand_internal(b, words);
+
+                if (a)
+                        {
+                        if (b->d)
+                                OPENSSL_free(b->d);
+                        b->d=a;
+                        b->dmax=words;
+                        }
+                else
+                        b = NULL;
+                }
+        return b;
+        }
+
+BIGNUM *BN_dup(const BIGNUM *a)
+        {
+        BIGNUM *r, *t;
+
+        if (a == NULL) return NULL;
+
+        bn_check_top(a);
+
+        t = BN_new();
+        if (t == NULL) return(NULL);
+        r = BN_copy(t, a);
+        /* now  r == t || r == NULL */
+        if (r == NULL)
+                BN_free(t);
+        return r;
+        }
+
+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;
+                }
+        switch (b->top&3)
+                {
+                case 3: A[2]=B[2];
+                case 2: A[1]=B[1];
+                case 1: A[0]=B[0];
+                case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */
+                }
+#else
+        memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
+#endif
+
+/*      memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
+        a->top=b->top;
+        if ((a->top == 0) && (a->d != NULL))
+                a->d[0]=0;
+        a->neg=b->neg;
+        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;
+        
+        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);
+        }
+
+
+void BN_clear(BIGNUM *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)
+        {
+        int i,n;
+        BN_ULONG ret=0;
+
+        n=BN_num_bytes(a);
+        if (n > sizeof(BN_ULONG))
+                return(BN_MASK2);
+        for (i=a->top-1; i>=0; i--)
+                {
+#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
+                ret<<=BN_BITS4; /* stops the compiler complaining */
+                ret<<=BN_BITS4;
+#else
+                ret=0;
+#endif
+                ret|=a->d[i];
+                }
+        return(ret);
+        }
+
+int BN_set_word(BIGNUM *a, BN_ULONG w)
+        {
+        int i,n;
+        if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);
+
+        n=sizeof(BN_ULONG)/BN_BYTES;
+        a->neg=0;
+        a->top=0;
+        a->d[0]=(BN_ULONG)w&BN_MASK2;
+        if (a->d[0] != 0) a->top=1;
+        for (i=1; i<n; i++)
+                {
+                /* the following is done instead of
+                 * w>>=BN_BITS2 so compilers don't complain
+                 * on builds where sizeof(long) == BN_TYPES */
+#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
+                w>>=BN_BITS4;
+                w>>=BN_BITS4;
+#else
+                w=0;
+#endif
+                a->d[i]=(BN_ULONG)w&BN_MASK2;
+                if (a->d[i] != 0) a->top=i+1;
+                }
+        return(1);
+        }
+
+BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
+        {
+        unsigned int i,m;
+        unsigned int n;
+        BN_ULONG l;
+
+        if (ret == NULL) ret=BN_new();
+        if (ret == NULL) return(NULL);
+        l=0;
+        n=len;
+        if (n == 0)
+                {
+                ret->top=0;
+                return(ret);
+                }
+        if (bn_expand(ret,(int)(n+2)*8) == NULL)
+                return(NULL);
+        i=((n-1)/BN_BYTES)+1;
+        m=((n-1)%(BN_BYTES));
+        ret->top=i;
+        ret->neg=0;
+        while (n-- > 0)
+                {
+                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_fix_top(ret);
+        return(ret);
+        }
+
+/* ignore negative */
+int BN_bn2bin(const BIGNUM *a, unsigned char *to)
+        {
+        int n,i;
+        BN_ULONG l;
+
+        n=i=BN_num_bytes(a);
+        while (i-- > 0)
+                {
+                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;
+
+        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);
+        return(1);
+        }
+
+int BN_clear_bit(BIGNUM *a, int n)
+        {
+        int i,j;
+
+        i=n/BN_BITS2;
+        j=n%BN_BITS2;
+        if (a->top <= i) return(0);
+
+        a->d[i]&=(~(((BN_ULONG)1)<<j));
+        bn_fix_top(a);
+        return(1);
+        }
+
+int BN_is_bit_set(const BIGNUM *a, int n)
+        {
+        int i,j;
+
+        if (n < 0) return(0);
+        i=n/BN_BITS2;
+        j=n%BN_BITS2;
+        if (a->top <= i) return(0);
+        return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
+        }
+
+int BN_mask_bits(BIGNUM *a, int n)
+        {
+        int b,w;
+
+        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_fix_top(a);
+        return(1);
+        }
+
+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);
+        }