diff options
Diffstat (limited to 'plugins/CryptoPP/crypto/src/gf256.cpp')
| -rw-r--r-- | plugins/CryptoPP/crypto/src/gf256.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/plugins/CryptoPP/crypto/src/gf256.cpp b/plugins/CryptoPP/crypto/src/gf256.cpp new file mode 100644 index 0000000000..3649f75592 --- /dev/null +++ b/plugins/CryptoPP/crypto/src/gf256.cpp @@ -0,0 +1,34 @@ +// gf256.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "gf256.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+GF256::Element GF256::Multiply(Element a, Element b) const
+{
+ word result = 0, t = b;
+
+ for (unsigned int i=0; i<8; i++)
+ {
+ result <<= 1;
+ if (result & 0x100)
+ result ^= m_modulus;
+
+ t <<= 1;
+ if (t & 0x100)
+ result ^= a;
+ }
+
+ return (GF256::Element) result;
+}
+
+GF256::Element GF256::MultiplicativeInverse(Element a) const
+{
+ Element result = a;
+ for (int i=1; i<7; i++)
+ result = Multiply(Square(result), a);
+ return Square(result);
+}
+
+NAMESPACE_END
|