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-rw-r--r--crypto/bn/bn_div.c111
1 files changed, 26 insertions, 85 deletions
diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c
index bc37671cf138..70add10c7d6c 100644
--- a/crypto/bn/bn_div.c
+++ b/crypto/bn/bn_div.c
@@ -1,64 +1,14 @@
-/* crypto/bn/bn_div.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
+/*
+ * Copyright 1995-2018 The OpenSSL Project Authors. 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.]
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
-#include <stdio.h>
#include <openssl/bn.h>
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
/* The old slow way */
@@ -74,17 +24,17 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
bn_check_top(d);
if (BN_is_zero(d)) {
BNerr(BN_F_BN_DIV, BN_R_DIV_BY_ZERO);
- return (0);
+ return 0;
}
if (BN_ucmp(m, d) < 0) {
if (rem != NULL) {
if (BN_copy(rem, m) == NULL)
- return (0);
+ return 0;
}
if (dv != NULL)
BN_zero(dv);
- return (1);
+ return 1;
}
BN_CTX_start(ctx);
@@ -131,7 +81,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
ret = 1;
end:
BN_CTX_end(ctx);
- return (ret);
+ return ret;
}
#else
@@ -147,8 +97,6 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
* understand why...);
* - divl doesn't only calculate quotient, but also leaves
* remainder in %edx which we can definitely use here:-)
- *
- * <appro@fy.chalmers.se>
*/
# undef bn_div_words
# define bn_div_words(n0,n1,d0) \
@@ -163,7 +111,6 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
# elif defined(__x86_64) && defined(SIXTY_FOUR_BIT_LONG)
/*
* Same story here, but it's 128-bit by 64-bit division. Wow!
- * <appro@fy.chalmers.se>
*/
# undef bn_div_words
# define bn_div_words(n0,n1,d0) \
@@ -180,7 +127,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
# endif /* OPENSSL_NO_ASM */
/*-
- * BN_div computes dv := num / divisor, rounding towards
+ * BN_div computes dv := num / divisor, rounding towards
* zero, and sets up rm such that dv*divisor + rm = num holds.
* Thus:
* dv->neg == num->neg ^ divisor->neg (unless the result is zero)
@@ -227,28 +174,25 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
if (BN_is_zero(divisor)) {
BNerr(BN_F_BN_DIV, BN_R_DIV_BY_ZERO);
- return (0);
+ return 0;
}
if (!no_branch && BN_ucmp(num, divisor) < 0) {
if (rm != NULL) {
if (BN_copy(rm, num) == NULL)
- return (0);
+ return 0;
}
if (dv != NULL)
BN_zero(dv);
- return (1);
+ return 1;
}
BN_CTX_start(ctx);
+ res = (dv == NULL) ? BN_CTX_get(ctx) : dv;
tmp = BN_CTX_get(ctx);
snum = BN_CTX_get(ctx);
sdiv = BN_CTX_get(ctx);
- if (dv == NULL)
- res = BN_CTX_get(ctx);
- else
- res = dv;
- if (sdiv == NULL || res == NULL || tmp == NULL || snum == NULL)
+ if (sdiv == NULL)
goto err;
/* First we normalise the numbers */
@@ -290,6 +234,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
wnum.neg = 0;
wnum.d = &(snum->d[loop]);
wnum.top = div_n;
+ wnum.flags = BN_FLG_STATIC_DATA;
/*
* only needed when BN_ucmp messes up the values between top and max
*/
@@ -304,9 +249,9 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
wnump = &(snum->d[num_n - 1]);
/* Setup to 'res' */
- res->neg = (num->neg ^ divisor->neg);
if (!bn_wexpand(res, (loop + 1)))
goto err;
+ res->neg = (num->neg ^ divisor->neg);
res->top = loop - no_branch;
resp = &(res->d[loop - 1]);
@@ -328,6 +273,9 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
res->top--;
}
+ /* Increase the resp pointer so that we never create an invalid pointer. */
+ resp++;
+
/*
* if res->top == 0 then clear the neg value otherwise decrease the resp
* pointer
@@ -337,7 +285,7 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
else
resp--;
- for (i = 0; i < loop - 1; i++, wnump--, resp--) {
+ for (i = 0; i < loop - 1; i++, wnump--) {
BN_ULONG q, l0;
/*
* the first part of the loop uses the top two words of snum and sdiv
@@ -362,10 +310,6 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
q = (BN_ULONG)(((((BN_ULLONG) n0) << BN_BITS2) | n1) / d0);
# else
q = bn_div_words(n0, n1, d0);
-# ifdef BN_DEBUG_LEVITTE
- fprintf(stderr, "DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\
-X) -> 0x%08X\n", n0, n1, d0, q);
-# endif
# endif
# ifndef REMAINDER_IS_ALREADY_CALCULATED
@@ -390,10 +334,6 @@ X) -> 0x%08X\n", n0, n1, d0, q);
BN_ULONG t2l, t2h;
q = bn_div_words(n0, n1, d0);
-# ifdef BN_DEBUG_LEVITTE
- fprintf(stderr, "DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\
-X) -> 0x%08X\n", n0, n1, d0, q);
-# endif
# ifndef REMAINDER_IS_ALREADY_CALCULATED
rem = (n1 - q * d0) & BN_MASK2;
# endif
@@ -451,6 +391,7 @@ X) -> 0x%08X\n", n0, n1, d0, q);
(*wnump)++;
}
/* store part of the result */
+ resp--;
*resp = q;
}
bn_correct_top(snum);
@@ -468,10 +409,10 @@ X) -> 0x%08X\n", n0, n1, d0, q);
if (no_branch)
bn_correct_top(res);
BN_CTX_end(ctx);
- return (1);
+ return 1;
err:
bn_check_top(rm);
BN_CTX_end(ctx);
- return (0);
+ return 0;
}
#endif