diff options
author | Geoff Thorpe <geoff@openssl.org> | 2004-03-25 04:32:24 +0000 |
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committer | Geoff Thorpe <geoff@openssl.org> | 2004-03-25 04:32:24 +0000 |
commit | c86f2054f39c7005bc03f91db2d7bcf38f0a92ac (patch) | |
tree | d44ff598397b7c8c61b254d32aaba1479a34deda /crypto/bn/bn_recp.c | |
parent | 5c98b2caf5ce545fbf77611431c7084979da8177 (diff) |
Adjust various bignum functions to use BN_CTX for variables instead of
locally initialising their own.
NB: I've removed the "BN_clear_free()" loops for the exit-paths in some of
these functions, and that may be a major part of the performance
improvements we're seeing. The "free" part can be removed because we're
using BN_CTX. The "clear" part OTOH can be removed because BN_CTX
destruction automatically performs this task, so performing it inside
functions that may be called repeatedly is wasteful. This is currently safe
within openssl due to the fact that BN_CTX objects are never created for
longer than a single high-level operation. However, that is only because
there's currently no mechanism in openssl for thread-local storage. Beyond
that, this might be an issue for applications using the bignum API directly
and caching their own BN_CTX objects. The solution is to introduce a flag
to BN_CTX_start() that allows its variables to be automatically sanitised
on release during BN_CTX_end(). This way any higher-level function (and
perhaps the application) can specify this flag in its own
BN_CTX_start()/BN_CTX_end() pair, and this will cause inner-loop functions
specifying the flag to be ignored so that sanitisation is handled only once
back out at the higher level. I will be implementing this in the near
future.
Diffstat (limited to 'crypto/bn/bn_recp.c')
-rw-r--r-- | crypto/bn/bn_recp.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/crypto/bn/bn_recp.c b/crypto/bn/bn_recp.c index 05b845b2a1..a08489e04a 100644 --- a/crypto/bn/bn_recp.c +++ b/crypto/bn/bn_recp.c @@ -217,17 +217,18 @@ err: int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx) { int ret= -1; - BIGNUM t; + BIGNUM *t; - BN_init(&t); + BN_CTX_start(ctx); + if((t = BN_CTX_get(ctx)) == NULL) goto err; - if (!BN_set_bit(&t,len)) goto err; + if (!BN_set_bit(t,len)) goto err; - if (!BN_div(r,NULL,&t,m,ctx)) goto err; + if (!BN_div(r,NULL,t,m,ctx)) goto err; ret=len; err: - BN_free(&t); bn_check_top(r); + BN_CTX_end(ctx); return(ret); } |