des: Added Curl_des_set_odd_parity()

Added Curl_des_set_odd_parity() for use when cryptography engines
don't include this functionality.

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/curl_des.c b/lib/curl_des.c
new file mode 100644
index 000000000..ba6249635
--- /dev/null
+++ b/lib/curl_des.c
@@ -0,0 +1,63 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2015, Steve Holme, <steve_holme@hotmail.com>.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if defined(USE_NTLM) && (!defined(USE_SSLEAY) || defined(HAVE_BORINGSSL))
+
+#include "curl_des.h"
+
+/*
+ * Curl_des_set_odd_parity()
+ *
+ * This is used to apply odd parity to the given byte array. It is typically
+ * used by when a cryptography engines doesn't have it's own version.
+ *
+ * The function is a port of the Java based oddParity() function over at:
+ *
+ * http://davenport.sourceforge.net/ntlm.html
+ *
+ * Parameters:
+ *
+ * bytes       [in/out] - The data whose parity bits are to be adjusted for
+ *                        odd parity.
+ * len         [out]    - The length of the data.
+ */
+void Curl_des_set_odd_parity(unsigned char *bytes, size_t len)
+{
+  size_t i;
+
+  for(i = 0; i < len; i++) {
+    unsigned char b = bytes[i];
+
+    bool needs_parity = (((b >> 7) ^ (b >> 6) ^ (b >> 5) ^
+                          (b >> 4) ^ (b >> 3) ^ (b >> 2) ^
+                          (b >> 1)) & 0x01) == 0;
+
+    if(needs_parity)
+      bytes[i] |= 0x01;
+    else
+      bytes[i] &= 0xfe;
+  }
+}
+
+#endif /* USE_NTLM && (!USE_SSLEAY || HAVE_BORINGSSL) */