Convert RSA blinding to new multi-threading API

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
diff --git a/crypto/rsa/rsa_ossl.c b/crypto/rsa/rsa_ossl.c
index 925cf65..8d3383b 100644
--- a/crypto/rsa/rsa_ossl.c
+++ b/crypto/rsa/rsa_ossl.c
@@ -248,7 +248,6 @@
 static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
 {
     BN_BLINDING *ret;
-    CRYPTO_THREADID cur;
 
     CRYPTO_THREAD_write_lock(rsa->lock);
 
@@ -260,8 +259,7 @@
     if (ret == NULL)
         goto err;
 
-    CRYPTO_THREADID_current(&cur);
-    if (!CRYPTO_THREADID_cmp(&cur, BN_BLINDING_thread_id(ret))) {
+    if (BN_BLINDING_is_current_thread(ret)) {
         /* rsa->blinding is ours! */
 
         *local = 1;
@@ -299,9 +297,11 @@
          * Shared blinding: store the unblinding factor outside BN_BLINDING.
          */
         int ret;
-        CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
+
+        BN_BLINDING_lock(b);
         ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
-        CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
+        BN_BLINDING_unlock(b);
+
         return ret;
     }
 }