third_party/tlslite/patches/thread_safe_python_rsa_key.patch

diff --git a/third_party/tlslite/tlslite/utils/python_rsakey.py b/third_party/tlslite/tlslite/utils/python_rsakey.py
index 1281f1dc899c..a62fc68b4701 100644
--- a/third_party/tlslite/tlslite/utils/python_rsakey.py
+++ b/third_party/tlslite/tlslite/utils/python_rsakey.py
@@ -2,7 +2,7 @@
 # See the LICENSE file for legal information regarding use of this file.
 
 """Pure-Python RSA implementation."""
-
+import threading
 from .cryptomath import *
 from .asn1parser import ASN1Parser
 from .rsakey import *
@@ -22,33 +22,36 @@ class Python_RSAKey(RSAKey):
         self.qInv = qInv
         self.blinder = 0
         self.unblinder = 0
+        self._lock = threading.Lock()
 
     def hasPrivateKey(self):
         return self.d != 0
 
-    def _rawPrivateKeyOp(self, m):
-        #Create blinding values, on the first pass:
-        if not self.blinder:
-            self.unblinder = getRandomNumber(2, self.n)
-            self.blinder = powMod(invMod(self.unblinder, self.n), self.e,
-                                  self.n)
-
-        #Blind the input
-        m = (m * self.blinder) % self.n
+    def _rawPrivateKeyOp(self, message):
+        with self._lock:
+            # Create blinding values, on the first pass:
+            if not self.blinder:
+                self.unblinder = getRandomNumber(2, self.n)
+                self.blinder = powMod(invMod(self.unblinder, self.n), self.e,
+                                      self.n)
+            unblinder = self.unblinder
+            blinder = self.blinder
 
-        #Perform the RSA operation
-        c = self._rawPrivateKeyOpHelper(m)
+            # Update blinding values
+            self.blinder = (self.blinder * self.blinder) % self.n
+            self.unblinder = (self.unblinder * self.unblinder) % self.n
 
-        #Unblind the output
-        c = (c * self.unblinder) % self.n
+        # Blind the input
+        message = (message * blinder) % self.n
 
-        #Update blinding values
-        self.blinder = (self.blinder * self.blinder) % self.n
-        self.unblinder = (self.unblinder * self.unblinder) % self.n
+        # Perform the RSA operation
+        cipher = self._rawPrivateKeyOpHelper(message)
 
-        #Return the output
-        return c
+        # Unblind the output
+        cipher = (cipher * unblinder) % self.n
 
+        # Return the output
+        return cipher
 
     def _rawPrivateKeyOpHelper(self, m):
         #Non-CRT version