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authorMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
committerMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
commit9d5ed350a749368c84254c11e7616ce3c891193a (patch)
tree6dacbff2e9f5c60a1568382db55c72dd6d2ce925 /libtomcrypt/src/encauth/ocb/ocb_ntz.c
parentca52f070aecf91e75f6ae6c87d4ae1a2189ccb14 (diff)
parent5ea605d8de5b4438deb4fa86c5231710dd09f934 (diff)
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e)
to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933) --HG-- extra : convert_revision : d26d5eb2837f46b56a33fb0e7573aa0201abd4d5
Diffstat (limited to 'libtomcrypt/src/encauth/ocb/ocb_ntz.c')
-rw-r--r--libtomcrypt/src/encauth/ocb/ocb_ntz.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/libtomcrypt/src/encauth/ocb/ocb_ntz.c b/libtomcrypt/src/encauth/ocb/ocb_ntz.c
new file mode 100644
index 0000000..8100ec0
--- /dev/null
+++ b/libtomcrypt/src/encauth/ocb/ocb_ntz.c
@@ -0,0 +1,42 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+
+/**
+ @file ocb_ntz.c
+ OCB implementation, internal function, by Tom St Denis
+*/
+
+#include "tomcrypt.h"
+
+#ifdef OCB_MODE
+
+/**
+ Returns the number of leading zero bits [from lsb up]
+ @param x The 32-bit value to observe
+ @return The number of bits [from the lsb up] that are zero
+*/
+int ocb_ntz(unsigned long x)
+{
+ int c;
+ x &= 0xFFFFFFFFUL;
+ c = 0;
+ while ((x & 1) == 0) {
+ ++c;
+ x >>= 1;
+ }
+ return c;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_ntz.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/03/31 14:15:35 $ */