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author | Geoff Thorpe <geoff@openssl.org> | 2004-03-13 23:04:15 +0000 |
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committer | Geoff Thorpe <geoff@openssl.org> | 2004-03-13 23:04:15 +0000 |
commit | 5d735465d1b5b7853506979946ad5730cc3615bb (patch) | |
tree | 36cb4ab497280280a9a8f163853c9362b0ca424c /crypto | |
parent | 9e051bac139ce07f846d88b90f3ec514c39ea416 (diff) | |
download | openssl-new-5d735465d1b5b7853506979946ad5730cc3615bb.tar.gz |
The efforts to eliminate the dual-representation of zero and to ensure
bignums are passed in and out of functions and APIs in a consistent form
has highlighted that zero-valued bignums don't need any allocated word
data. The use of BN_set_word() to initialise a bignum to zero causes
needless allocation and gives it a return value that must be checked. This
change converts BN_zero() to a self-contained macro that has no
return/expression value and does not cause any expansion of bignum data.
Note, it would be tempting to rewrite the deprecated version as a
success-valued comma expression, such as;
#define BN_zero(a) ((a)->top = (a)->neg = 0, 1)
However, this evaluates 'a' twice and would confuse initialisation loops
(eg. while(..) { BN_zero(bn++) } ). As such, the deprecated version
continues to use BN_set_word().
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/bn/bn.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h index f58d5f55a0..a01f193daa 100644 --- a/crypto/bn/bn.h +++ b/crypto/bn/bn.h @@ -372,7 +372,17 @@ int BN_GENCB_call(BN_GENCB *cb, int a, int b); #define BN_is_odd(a) (((a)->top > 0) && ((a)->d[0] & 1)) #define BN_one(a) (BN_set_word((a),1)) +#define BN_zero_ex(a) \ + do { \ + BIGNUM *_tmp_bn = (a); \ + _tmp_bn->top = 0; \ + _tmp_bn->neg = 0; \ + } while(0) +#ifdef OPENSSL_NO_DEPRECATED +#define BN_zero(a) BN_zero_ex(a) +#else #define BN_zero(a) (BN_set_word((a),0)) +#endif /* BN_set_sign(BIGNUM *, int) sets the sign of a BIGNUM * (0 for a non-negative value, 1 for negative) */ #define BN_set_sign(a,b) ((a)->neg = (b)) |