diff options
Diffstat (limited to 'plugins/CryptoPP/crypto/src/idea.cpp')
| -rw-r--r-- | plugins/CryptoPP/crypto/src/idea.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/plugins/CryptoPP/crypto/src/idea.cpp b/plugins/CryptoPP/crypto/src/idea.cpp new file mode 100644 index 0000000000..19e9330579 --- /dev/null +++ b/plugins/CryptoPP/crypto/src/idea.cpp @@ -0,0 +1,192 @@ +// idea.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "idea.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+static const int IDEA_KEYLEN=(6*IDEA::ROUNDS+4); // key schedule length in # of word16s
+
+#define low16(x) ((x)&0xffff) // compiler should be able to optimize this away if word is 16 bits
+#define high16(x) ((x)>>16)
+
+CRYPTOPP_COMPILE_ASSERT(sizeof(IDEA::Word) >= 2);
+
+// should use an inline function but macros are still faster in MSVC 4.0
+#define DirectMUL(a,b) \
+{ \
+ assert(b <= 0xffff); \
+ \
+ word32 p=(word32)low16(a)*b; \
+ \
+ if (p) \
+ { \
+ p = low16(p) - high16(p); \
+ a = (IDEA::Word)p - (IDEA::Word)high16(p); \
+ } \
+ else \
+ a = 1-a-b; \
+}
+
+#ifdef IDEA_LARGECACHE
+bool IDEA::Base::tablesBuilt = false;
+word16 IDEA::Base::log[0x10000];
+word16 IDEA::Base::antilog[0x10000];
+
+void IDEA::Base::BuildLogTables()
+{
+ if (tablesBuilt)
+ return;
+ else
+ {
+ tablesBuilt = true;
+
+ IDEA::Word x=1;
+ word32 i;
+
+ for (i=0; i<0x10000; i++)
+ {
+ antilog[i] = (word16)x;
+ DirectMUL(x, 3);
+ }
+
+ for (i=0; i<0x10000; i++)
+ log[antilog[i]] = (word16)i;
+ }
+}
+
+void IDEA::Base::LookupKeyLogs()
+{
+ IDEA::Word* Z=key;
+ int r=ROUNDS;
+ do
+ {
+ Z[0] = log[Z[0]];
+ Z[3] = log[Z[3]];
+ Z[4] = log[Z[4]];
+ Z[5] = log[Z[5]];
+ Z+=6;
+ } while (--r);
+ Z[0] = log[Z[0]];
+ Z[3] = log[Z[3]];
+}
+
+inline void IDEA::Base::LookupMUL(IDEA::Word &a, IDEA::Word b)
+{
+ a = antilog[low16(log[low16(a)]+b)];
+}
+#endif // IDEA_LARGECACHE
+
+void IDEA::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
+{
+ AssertValidKeyLength(length);
+
+#ifdef IDEA_LARGECACHE
+ BuildLogTables();
+#endif
+
+ EnKey(userKey);
+
+ if (!IsForwardTransformation())
+ DeKey();
+
+#ifdef IDEA_LARGECACHE
+ LookupKeyLogs();
+#endif
+}
+
+void IDEA::Base::EnKey (const byte *userKey)
+{
+ unsigned int i;
+
+ for (i=0; i<8; i++)
+ m_key[i] = ((IDEA::Word)userKey[2*i]<<8) | userKey[2*i+1];
+
+ for (; i<IDEA_KEYLEN; i++)
+ {
+ unsigned int j = RoundDownToMultipleOf(i,8U)-8;
+ m_key[i] = low16((m_key[j+(i+1)%8] << 9) | (m_key[j+(i+2)%8] >> 7));
+ }
+}
+
+static IDEA::Word MulInv(IDEA::Word x)
+{
+ IDEA::Word y=x;
+ for (unsigned i=0; i<15; i++)
+ {
+ DirectMUL(y,low16(y));
+ DirectMUL(y,x);
+ }
+ return low16(y);
+}
+
+static inline IDEA::Word AddInv(IDEA::Word x)
+{
+ return low16(0-x);
+}
+
+void IDEA::Base::DeKey()
+{
+ FixedSizeSecBlock<IDEA::Word, 6*ROUNDS+4> tempkey;
+ unsigned int i;
+
+ for (i=0; i<ROUNDS; i++)
+ {
+ tempkey[i*6+0] = MulInv(m_key[(ROUNDS-i)*6+0]);
+ tempkey[i*6+1] = AddInv(m_key[(ROUNDS-i)*6+1+(i>0)]);
+ tempkey[i*6+2] = AddInv(m_key[(ROUNDS-i)*6+2-(i>0)]);
+ tempkey[i*6+3] = MulInv(m_key[(ROUNDS-i)*6+3]);
+ tempkey[i*6+4] = m_key[(ROUNDS-1-i)*6+4];
+ tempkey[i*6+5] = m_key[(ROUNDS-1-i)*6+5];
+ }
+
+ tempkey[i*6+0] = MulInv(m_key[(ROUNDS-i)*6+0]);
+ tempkey[i*6+1] = AddInv(m_key[(ROUNDS-i)*6+1]);
+ tempkey[i*6+2] = AddInv(m_key[(ROUNDS-i)*6+2]);
+ tempkey[i*6+3] = MulInv(m_key[(ROUNDS-i)*6+3]);
+
+ m_key = tempkey;
+}
+
+#ifdef IDEA_LARGECACHE
+#define MUL(a,b) LookupMUL(a,b)
+#else
+#define MUL(a,b) DirectMUL(a,b)
+#endif
+
+void IDEA::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+ typedef BlockGetAndPut<word16, BigEndian> Block;
+
+ const IDEA::Word *key = m_key;
+ IDEA::Word x0,x1,x2,x3,t0,t1;
+ Block::Get(inBlock)(x0)(x1)(x2)(x3);
+
+ for (unsigned int i=0; i<ROUNDS; i++)
+ {
+ MUL(x0, key[i*6+0]);
+ x1 += key[i*6+1];
+ x2 += key[i*6+2];
+ MUL(x3, key[i*6+3]);
+ t0 = x0^x2;
+ MUL(t0, key[i*6+4]);
+ t1 = t0 + (x1^x3);
+ MUL(t1, key[i*6+5]);
+ t0 += t1;
+ x0 ^= t1;
+ x3 ^= t0;
+ t0 ^= x1;
+ x1 = x2^t1;
+ x2 = t0;
+ }
+
+ MUL(x0, key[ROUNDS*6+0]);
+ x2 += key[ROUNDS*6+1];
+ x1 += key[ROUNDS*6+2];
+ MUL(x3, key[ROUNDS*6+3]);
+
+ Block::Put(xorBlock, outBlock)(x0)(x2)(x1)(x3);
+}
+
+NAMESPACE_END
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