File openssl-add-BN_FLG_FIXED_TOP-flag.patch of Package openssl1

From b7862891fed4cfb5ec36a31d35e14b51bf26d01e Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Fri, 6 Jul 2018 15:02:29 +0200
Subject: [PATCH] bn/bn_lib.c: add BN_FLG_FIXED_TOP flag.

The new flag marks vectors that were not treated with bn_correct_top,
in other words such vectors are permitted to be zero padded. For now
it's BN_DEBUG-only flag, as initial use case for zero-padded vectors
would be controlled Montgomery multiplication/exponentiation, not
general purpose. For general purpose use another type might be more
appropriate. Advantage of this suggestion is that it's possible to
back-port it...

bn/bn_div.c: fix memory sanitizer problem.
bn/bn_sqr.c: harmonize with BN_mul.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6707)

(cherry picked from commit 305b68f1a2b6d4d0aa07a6ab47ac372f067a40bb)

Resolved conflicts:
	crypto/bn/bn_lcl.h
---
 crypto/bn/bn_div.c |  1 +
 crypto/bn/bn_lcl.h | 18 +++++++++++++++---
 crypto/bn/bn_lib.c | 15 +++++++++++----
 crypto/bn/bn_sqr.c | 10 ++--------
 4 files changed, 29 insertions(+), 15 deletions(-)

Index: openssl-1.0.1i/crypto/bn/bn_div.c
===================================================================
--- openssl-1.0.1i.orig/crypto/bn/bn_div.c
+++ openssl-1.0.1i/crypto/bn/bn_div.c
@@ -270,7 +270,10 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const
 	wnum.neg   = 0;
 	wnum.d     = &(snum->d[loop]);
 	wnum.top   = div_n;
-	/* only needed when BN_ucmp messes up the values between top and max */
+	wnum.flags = BN_FLG_STATIC_DATA;
+	/*
+	 * only needed when BN_ucmp messes up the values between top and max
+	 */
 	wnum.dmax  = snum->dmax - loop; /* so we don't step out of bounds */
 
 	/* Get the top 2 words of sdiv */
Index: openssl-1.0.1i/crypto/bn/bn_lib.c
===================================================================
--- openssl-1.0.1i.orig/crypto/bn/bn_lib.c
+++ openssl-1.0.1i/crypto/bn/bn_lib.c
@@ -515,8 +515,9 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM
 	memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
 #endif
 
-	a->top=b->top;
 	a->neg=b->neg;
+	a->top=b->top;
+	a->flags |= b->flags & BN_FLG_FIXED_TOP;
 	bn_check_top(a);
 	return(a);
 	}
@@ -559,8 +560,9 @@ 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;
+	a->top=0;
+	a->flags &= ~BN_FLG_FIXED_TOP;
 	}
 
 BN_ULONG BN_get_word(const BIGNUM *a)
@@ -580,6 +582,7 @@ int BN_set_word(BIGNUM *a, BN_ULONG w)
 	a->neg = 0;
 	a->d[0] = w;
 	a->top = (w ? 1 : 0);
+	a->flags &= ~BN_FLG_FIXED_TOP;
 	bn_check_top(a);
 	return(1);
 	}
@@ -770,6 +773,7 @@ int BN_set_bit(BIGNUM *a, int n)
 		for(k=a->top; k<i+1; k++)
 			a->d[k]=0;
 		a->top=i+1;
+		a->flags &= ~BN_FLG_FIXED_TOP;
 		}
 
 	a->d[i]|=(((BN_ULONG)1)<<j);
Index: openssl-1.0.1i/crypto/bn/bn.h
===================================================================
--- openssl-1.0.1i.orig/crypto/bn/bn.h
+++ openssl-1.0.1i/crypto/bn/bn.h
@@ -415,8 +415,9 @@ int BN_GENCB_call(BN_GENCB *cb, int a, i
 #define BN_zero_ex(a) \
 	do { \
 		BIGNUM *_tmp_bn = (a); \
-		_tmp_bn->top = 0; \
 		_tmp_bn->neg = 0; \
+		_tmp_bn->top = 0; \
+		(a)->flags &= ~BN_FLG_FIXED_TOP; \
 	} while(0)
 #ifdef OPENSSL_NO_DEPRECATED
 #define BN_zero(a)	BN_zero_ex(a)
@@ -802,9 +803,10 @@ int RAND_pseudo_bytes(unsigned char *buf
 	do { \
 		const BIGNUM *_bnum2 = (a); \
 		if (_bnum2 != NULL) { \
-			assert((_bnum2->top == 0) || \
-			       (_bnum2->flags & BN_FLG_FIXED_TOP) || \
-			       (_bnum2->d[_bnum2->top - 1] != 0)); \
+		        int _top = _bnum2->top;	     \
+			OPENSSL_assert((_top == 0 && !_bnum2->neg) || \
+			       (_top && ((_bnum2->flags & BN_FLG_FIXED_TOP) \
+			                 || _bnum2->d[_top - 1] != 0))); \
 			bn_pollute(_bnum2); \
 		} \
 	} while(0)
@@ -839,6 +841,9 @@ int RAND_pseudo_bytes(unsigned char *buf
 			if (*(ftl--)) break; \
 		(a)->top = tmp_top; \
 		} \
+	if ((a)->top == 0) \
+            (a)->neg = 0; \
+        (a)->flags &= ~BN_FLG_FIXED_TOP; \
 	bn_pollute(a); \
 	}