Document a change I'd already made, and at the same time, correct the
change to work properly; BN_zero() should set 'neg' to zero as well as
'top' to match the behaviour of BN_new().
diff --git a/CHANGES b/CHANGES
index 22449a3..e675c90 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,10 @@
Changes between 0.9.7c and 0.9.8 [xx XXX xxxx]
+ *) BN_CTX_get() should return zero-valued bignums, providing the same
+ initialised value as BN_new().
+ [Geoff Thorpe, suggested by Ulf Möller]
+
*) Support for inhibitAnyPolicy certificate extension.
[Steve Henson]
@@ -21,7 +25,7 @@
some point, these tighter rules will become openssl's default to improve
maintainability, though the assert()s and other overheads will remain only
in debugging configurations. See bn.h for more details.
- [Geoff Thorpe]
+ [Geoff Thorpe, Nils Larsch, Ulf Möller]
*) BN_CTX_init() has been deprecated, as BN_CTX is an opaque structure
that can only be obtained through BN_CTX_new() (which implicitly
diff --git a/crypto/bn/bn_ctx.c b/crypto/bn/bn_ctx.c
index 9366ce6..f48055b 100644
--- a/crypto/bn/bn_ctx.c
+++ b/crypto/bn/bn_ctx.c
@@ -140,6 +140,7 @@
BIGNUM *BN_CTX_get(BN_CTX *ctx)
{
+ BIGNUM *ret;
/* Note: If BN_CTX_get is ever changed to allocate BIGNUMs dynamically,
* make sure that if BN_CTX_get fails once it will return NULL again
* until BN_CTX_end is called. (This is so that callers have to check
@@ -155,9 +156,10 @@
}
return NULL;
}
+ ret = ctx->bn + (ctx->tos++);
/* always return a 'zeroed' bignum */
- ctx->bn[ctx->tos].top = 0;
- return (&(ctx->bn[ctx->tos++]));
+ BN_zero(ret);
+ return ret;
}
void BN_CTX_end(BN_CTX *ctx)
diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c
index 556fcda..3b43929 100644
--- a/crypto/bn/bn_div.c
+++ b/crypto/bn/bn_div.c
@@ -214,7 +214,6 @@
res=BN_CTX_get(ctx);
else res=dv;
if (sdiv == NULL || res == NULL) goto err;
- tmp->neg=0;
/* First we normalise the numbers */
norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);
