Tune XTS for PowerPC

1 files changed, 48 insertions, 39 deletions

diff --git a/xts.cpp b/xts.cpp
index e2dec0cf..121e2f56 100644
--- a/xts.cpp
+++ b/xts.cpp
@@ -1,5 +1,12 @@
 // xts.cpp - written and placed in the public domain by Jeffrey Walton

 

+// Aarch32, Aarch64, Altivec and X86_64 include SIMD as part of the

+// base architecture. We can use the SIMD code below without an

+// architecture option. No runtime tests are required. Unfortunately,

+// we can't use it on Altivec because an architecture switch is required.

+// The updated XorBuffer gains 0.3 to 1.5 cpb on the architectures for

+// 16-byte block sizes.

+

 #include "pch.h"

 

 #include "xts.h"

@@ -33,13 +40,26 @@ ANONYMOUS_NAMESPACE_BEGIN
 

 using namespace CryptoPP;

 

-// Aarch32, Aarch64, Altivec and X86_64 include SIMD as part of the

-// base architecture. We can use the SIMD code below without an

-// architecture option. No runtime tests are required. Unfortunately,

-// we can't use it on Altivec because an architecture switch is required.

-// The updated XorBuffer gains 0.3 to 1.5 cpb on the architectures for

-// 16-byte block sizes. count must be a multiple of 16 since SIMD words

-// are used.

+#if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)

+

+using CryptoPP::AES;

+using CryptoPP::XTS_Mode;

+using CryptoPP::Threefish512;

+

+void Modes_TestInstantiations()

+{

+    XTS_Mode<AES>::Encryption m0;

+    XTS_Mode<AES>::Decryption m1;

+    XTS_Mode<AES>::Encryption m2;

+    XTS_Mode<AES>::Decryption m3;

+

+#if CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS

+    XTS_Mode<Threefish512>::Encryption m4;

+    XTS_Mode<Threefish512>::Decryption m5;

+#endif

+}

+#endif  // CRYPTOPP_DEBUG

+

 inline void XorBuffer(byte *output, const byte *input, const byte *mask, size_t count)

 {

     CRYPTOPP_ASSERT(count >= 16 && (count % 16 == 0));

@@ -154,46 +174,34 @@ inline void GF_Double(byte *inout, unsigned int len)
     GF_Double(inout, inout, len);

 }

 

-#if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)

+ANONYMOUS_NAMESPACE_END

 

-using CryptoPP::AES;

-using CryptoPP::XTS_Mode;

-using CryptoPP::Threefish512;

+NAMESPACE_BEGIN(CryptoPP)

 

-void Modes_TestInstantiations()

+void XTS_ModeBase::ThrowIfInvalidBlockSize(size_t length)

 {

-    XTS_Mode<AES>::Encryption m0;

-    XTS_Mode<AES>::Decryption m1;

-    XTS_Mode<AES>::Encryption m2;

-    XTS_Mode<AES>::Decryption m3;

-

 #if CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS

-    XTS_Mode<Threefish512>::Encryption m4;

-    XTS_Mode<Threefish512>::Decryption m5;

+    CRYPTOPP_ASSERT(length >= 16 && length <= 128 && IsPowerOf2(length));

+    if (length < 16 || length > 128 || !IsPowerOf2(length))

+        throw InvalidArgument(AlgorithmName() + ": block size of underlying block cipher is not valid");

+#else

+    CRYPTOPP_ASSERT(length == 16);

+    if (length != 16)

+        throw InvalidArgument(AlgorithmName() + ": block size of underlying block cipher is not 16");

 #endif

 }

-#endif

-

-ANONYMOUS_NAMESPACE_END

-

-NAMESPACE_BEGIN(CryptoPP)

 

 void XTS_ModeBase::ThrowIfInvalidKeyLength(size_t length)

 {

-    if (!AccessBlockCipher().IsValidKeyLength((length+1)/2))

+    CRYPTOPP_ASSERT(length % 2 == 0);

+    if (!GetBlockCipher().IsValidKeyLength((length+1)/2))

         throw InvalidKeyLength(AlgorithmName(), length);

 }

 

 void XTS_ModeBase::SetKey(const byte *key, size_t length, const NameValuePairs &params)

 {

-    CRYPTOPP_ASSERT(length % 2 == 0);

     ThrowIfInvalidKeyLength(length);

-

-#if (CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS == 0)

-    CRYPTOPP_ASSERT(BlockSize() == 16);

-    if (BlockSize() != 16)

-        throw InvalidArgument(AlgorithmName() + ": block size of underlying block cipher is not 16");

-#endif

+    ThrowIfInvalidBlockSize(BlockSize());

 

     const size_t klen = length/2;

     AccessBlockCipher().SetKey(key+0, klen, params);

@@ -233,16 +241,19 @@ void XTS_ModeBase::ResizeBuffers()
 

 void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t length)

 {

+    // data unit is multiple of 16 bytes

+    CRYPTOPP_ASSERT(length % BlockSize() == 0);

+

     const unsigned int blockSize = GetBlockCipher().BlockSize();

     const size_t parallelSize = blockSize*ParallelBlocks;

     size_t i = 0;

 

-    // data unit is multiple of 16 bytes

-    CRYPTOPP_ASSERT(length % blockSize == 0);

-

     // encrypt the data unit, optimal size at a time

     for ( ; i+parallelSize<=length; i+=parallelSize)

     {

+        // If this fires the GF_Double'ing below is not in sync

+        CRYPTOPP_ASSERT(ParallelBlocks == 4);

+

         // m_xregister[0] always points to the next tweak.

         GF_Double(m_xregister+1*blockSize, m_xregister+0*blockSize, blockSize);

         GF_Double(m_xregister+2*blockSize, m_xregister+1*blockSize, blockSize);

@@ -254,8 +265,8 @@ void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t len
         // encrypt one block, merge the tweak into the output block

         GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister, outString+i, parallelSize, BlockTransformation::BT_AllowParallel);

 

-        // Multiply T by alpha. m_xregister[0] always points to the next tweak.

-        GF_Double(m_xregister+0, m_xregister+3*blockSize, blockSize);

+        // m_xregister[0] always points to the next tweak.

+        GF_Double(m_xregister+0, m_xregister+(ParallelBlocks-1)*blockSize, blockSize);

     }

 

     // encrypt the data unit, blocksize at a time

@@ -273,8 +284,6 @@ void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t len
         // Multiply T by alpha

         GF_Double(m_xregister, blockSize);

     }

-

-    CRYPTOPP_ASSERT(i == length);

 }

 

 size_t XTS_ModeBase::ProcessLastBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)