Initial revision

git-svn-id: svn://svn.code.sf.net/p/cryptopp/code/trunk/c5@2 57ff6487-cd31-0410-9ec3-f628ee90f5f0

1 files changed, 83 insertions, 0 deletions

diff --git a/misc.cpp b/misc.cpp
new file mode 100644
index 0000000..c193b3f
--- /dev/null
+++ b/misc.cpp
@@ -0,0 +1,83 @@
+// misc.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "misc.h"
+#include "words.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+byte OAEP_P_DEFAULT[1];
+
+template<> void ByteReverse(word16 *, const word16 *, unsigned int);
+template<> void ByteReverse(word32 *, const word32 *, unsigned int);
+#ifdef WORD64_AVAILABLE
+template<> void ByteReverse(word64 *, const word64 *, unsigned int);
+#endif
+
+void xorbuf(byte *buf, const byte *mask, unsigned int count)
+{
+	if (((unsigned int)buf | (unsigned int)mask | count) % WORD_SIZE == 0)
+		XorWords((word *)buf, (const word *)mask, count/WORD_SIZE);
+	else
+	{
+		for (unsigned int i=0; i<count; i++)
+			buf[i] ^= mask[i];
+	}
+}
+
+void xorbuf(byte *output, const byte *input, const byte *mask, unsigned int count)
+{
+	if (((unsigned int)output | (unsigned int)input | (unsigned int)mask | count) % WORD_SIZE == 0)
+		XorWords((word *)output, (const word *)input, (const word *)mask, count/WORD_SIZE);
+	else
+	{
+		for (unsigned int i=0; i<count; i++)
+			output[i] = input[i] ^ mask[i];
+	}
+}
+
+unsigned int Parity(unsigned long value)
+{
+	for (unsigned int i=8*sizeof(value)/2; i>0; i/=2)
+		value ^= value >> i;
+	return (unsigned int)value&1;
+}
+
+unsigned int BytePrecision(unsigned long value)
+{
+	unsigned int i;
+	for (i=sizeof(value); i; --i)
+		if (value >> (i-1)*8)
+			break;
+
+	return i;
+}
+
+unsigned int BitPrecision(unsigned long value)
+{
+	if (!value)
+		return 0;
+
+	unsigned int l=0, h=8*sizeof(value);
+
+	while (h-l > 1)
+	{
+		unsigned int t = (l+h)/2;
+		if (value >> t)
+			l = t;
+		else
+			h = t;
+	}
+
+	return h;
+}
+
+unsigned long Crop(unsigned long value, unsigned int size)
+{
+	if (size < 8*sizeof(value))
+    	return (value & ((1L << size) - 1));
+	else
+		return value;
+}
+
+NAMESPACE_END