Thread-safety fixes

[openssl.git] / crypto / bn / bn_mont.c

diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index 7a8b67ba5547a99307aeb9fe6827539235bdf88c..b532305b80b08bc508342a167dac9cec92085cf0 100644 (file)
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -55,6 +55,59 @@
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]
  */
+/* ====================================================================
+ * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
 
 /*
  * Details about Montgomery multiplication algorithms can be found at
@@ -427,18 +480,30 @@ BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from)
 BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock,
                                        const BIGNUM *mod, BN_CTX *ctx)
        {
-       if (*pmont)
-               return *pmont;
-       CRYPTO_w_lock(lock);
+       int got_write_lock = 0;
+
+       CRYPTO_r_lock(lock);
        if (!*pmont)
                {
-               *pmont = BN_MONT_CTX_new();
-               if (*pmont && !BN_MONT_CTX_set(*pmont, mod, ctx))
+               CRYPTO_r_unlock(lock);
+               CRYPTO_w_lock(lock);
+               got_write_lock = 1;
+
+               if (!*pmont)
                        {
-                       BN_MONT_CTX_free(*pmont);
-                       *pmont = NULL;
+                       BN_MONT_CTX *mtmp;
+                       mtmp = BN_MONT_CTX_new();
+                       if (mtmp && !BN_MONT_CTX_set(mtmp, mod, ctx))
+                               BN_MONT_CTX_free(mtmp);
+                       else
+                               *pmont = mtmp;
                        }
                }
-       CRYPTO_w_unlock(lock);
+       
+       if (got_write_lock)
+               CRYPTO_w_unlock(lock);
+       else
+               CRYPTO_r_unlock(lock);
+               
        return *pmont;
        }