diff options
| author | Joel Sing <jsing@cvs.openbsd.org> | 2023-02-19 13:51:01 +0000 |
|---|---|---|
| committer | Joel Sing <jsing@cvs.openbsd.org> | 2023-02-19 13:51:01 +0000 |
| commit | 013a835a22a927d1216dab54a3bdce12e9bb941f (patch) | |
| tree | 896407b9e651ab50421c2211a5defc7a5ee1d817 /lib/libcrypto/bn | |
| parent | 647a4529e58891e46cf83cdae5f8af49d567647d (diff) | |
Rewrite BN_MONT_CTX_set_locked()
Rewrite and simplify BN_MONT_CTX_set_locked - in particular, only hold the
lock for a short period of time, rather than holding a write lock for a
module across an expensive operation.
ok tb@
Diffstat (limited to 'lib/libcrypto/bn')
| -rw-r--r-- | lib/libcrypto/bn/bn_mont.c | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/lib/libcrypto/bn/bn_mont.c b/lib/libcrypto/bn/bn_mont.c index bf38eac3030..cae8569b8da 100644 --- a/lib/libcrypto/bn/bn_mont.c +++ b/lib/libcrypto/bn/bn_mont.c @@ -1,4 +1,4 @@ -/* $OpenBSD: bn_mont.c,v 1.40 2023/02/19 13:44:29 jsing Exp $ */ +/* $OpenBSD: bn_mont.c,v 1.41 2023/02/19 13:51:00 jsing Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * @@ -330,35 +330,39 @@ err: } BN_MONT_CTX * -BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock, const BIGNUM *mod, +BN_MONT_CTX_set_locked(BN_MONT_CTX **pmctx, int lock, const BIGNUM *mod, BN_CTX *ctx) { - int got_write_lock = 0; - BN_MONT_CTX *ret; + BN_MONT_CTX *mctx = NULL; CRYPTO_r_lock(lock); - if (!*pmont) { - CRYPTO_r_unlock(lock); - CRYPTO_w_lock(lock); - got_write_lock = 1; - - if (!*pmont) { - ret = BN_MONT_CTX_new(); - if (ret && !BN_MONT_CTX_set(ret, mod, ctx)) - BN_MONT_CTX_free(ret); - else - *pmont = ret; - } - } + mctx = *pmctx; + CRYPTO_r_unlock(lock); - ret = *pmont; + if (mctx != NULL) + goto done; - if (got_write_lock) - CRYPTO_w_unlock(lock); - else - CRYPTO_r_unlock(lock); + if ((mctx = BN_MONT_CTX_new()) == NULL) + goto err; + if (!BN_MONT_CTX_set(mctx, mod, ctx)) + goto err; - return ret; + CRYPTO_w_lock(lock); + if (*pmctx != NULL) { + /* Someone else raced us... */ + BN_MONT_CTX_free(mctx); + mctx = *pmctx; + } else { + *pmctx = mctx; + } + CRYPTO_w_unlock(lock); + + goto done; + err: + BN_MONT_CTX_free(mctx); + mctx = NULL; + done: + return mctx; } #ifdef OPENSSL_NO_ASM |