First Commit

externals/cryptopp/xts.cpp

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+// 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"
+#include "misc.h"
+#include "modes.h"
+#include "cpu.h"
+
+#if defined(CRYPTOPP_DEBUG)
+# include "aes.h"
+# include "threefish.h"
+#endif
+
+// 0.3 to 0.4 cpb profit
+#if defined(__SSE2__) || defined(_M_X64)
+# include <emmintrin.h>
+#endif
+
+#if defined(__aarch32__) || defined(__aarch64__) || defined(_M_ARM64)
+# if (CRYPTOPP_ARM_NEON_HEADER) || (CRYPTOPP_ARM_ASIMD_AVAILABLE)
+#  include <arm_neon.h>
+# endif
+#endif
+
+#if defined(__ALTIVEC__)
+# include "ppc_simd.h"
+#endif
+
+ANONYMOUS_NAMESPACE_BEGIN
+
+using namespace CryptoPP;
+
+#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));
+
+#if defined(CRYPTOPP_DISABLE_ASM)
+    xorbuf(output, input, mask, count);
+
+#elif defined(__SSE2__) || defined(_M_X64)
+    for (size_t i=0; i<count; i+=16)
+        _mm_storeu_si128(M128_CAST(output+i),
+            _mm_xor_si128(
+                _mm_loadu_si128(CONST_M128_CAST(input+i)),
+                _mm_loadu_si128(CONST_M128_CAST(mask+i))));
+
+#elif defined(__aarch32__) || defined(__aarch64__) || defined(_M_ARM64)
+    for (size_t i=0; i<count; i+=16)
+        vst1q_u8(output+i, veorq_u8(vld1q_u8(input+i), vld1q_u8(mask+i)));
+
+#elif defined(__ALTIVEC__)
+    for (size_t i=0; i<count; i+=16)
+        VecStore(VecXor(VecLoad(input+i), VecLoad(mask+i)), output+i);
+
+#else
+    xorbuf(output, input, mask, count);
+#endif
+}
+
+inline void XorBuffer(byte *buf, const byte *mask, size_t count)
+{
+    XorBuffer(buf, buf, mask, count);
+}
+
+// Borrowed from CMAC, but little-endian representation
+inline void GF_Double(byte *out, const byte* in, unsigned int len)
+{
+#if defined(CRYPTOPP_WORD128_AVAILABLE)
+    word128 carry = 0, x;
+    for (size_t i=0, idx=0; i<len/16; ++i, idx+=16)
+    {
+        x = GetWord<word128>(false, LITTLE_ENDIAN_ORDER, in+idx);
+        word128 y = (x >> 127); x = (x << 1) + carry;
+        PutWord<word128>(false, LITTLE_ENDIAN_ORDER, out+idx, x);
+        carry = y;
+    }
+#elif defined(_M_X64) || defined(_M_ARM64) || defined(_LP64) || defined(__LP64__)
+    word64 carry = 0, x;
+    for (size_t i=0, idx=0; i<len/8; ++i, idx+=8)
+    {
+        x = GetWord<word64>(false, LITTLE_ENDIAN_ORDER, in+idx);
+        word64 y = (x >> 63); x = (x << 1) + carry;
+        PutWord<word64>(false, LITTLE_ENDIAN_ORDER, out+idx, x);
+        carry = y;
+    }
+#else
+    word32 carry = 0, x;
+    for (size_t i=0, idx=0; i<len/4; ++i, idx+=4)
+    {
+        x = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, in+idx);
+        word32 y = (x >> 31); x = (x << 1) + carry;
+        PutWord<word32>(false, LITTLE_ENDIAN_ORDER, out+idx, x);
+        carry = y;
+    }
+#endif
+
+#if CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS
+
+    CRYPTOPP_ASSERT(IsPowerOf2(len));
+    CRYPTOPP_ASSERT(len >= 16);
+    CRYPTOPP_ASSERT(len <= 128);
+
+    byte* k = out;
+    if (carry)
+    {
+        switch (len)
+        {
+        case 16:
+        {
+            const size_t LEIDX = 16-1;
+            k[LEIDX-15] ^= 0x87;
+            break;
+        }
+        case 32:
+        {
+            // https://crypto.stackexchange.com/q/9815/10496
+            // Polynomial x^256 + x^10 + x^5 + x^2 + 1
+            const size_t LEIDX = 32-1;
+            k[LEIDX-30] ^= 4;
+            k[LEIDX-31] ^= 0x25;
+            break;
+        }
+        case 64:
+        {
+            // https://crypto.stackexchange.com/q/9815/10496
+            // Polynomial x^512 + x^8 + x^5 + x^2 + 1
+            const size_t LEIDX = 64-1;
+            k[LEIDX-62] ^= 1;
+            k[LEIDX-63] ^= 0x25;
+            break;
+        }
+        case 128:
+        {
+            // https://crypto.stackexchange.com/q/9815/10496
+            // Polynomial x^1024 + x^19 + x^6 + x + 1
+            const size_t LEIDX = 128-1;
+            k[LEIDX-125] ^= 8;
+            k[LEIDX-126] ^= 0x00;
+            k[LEIDX-127] ^= 0x43;
+            break;
+        }
+        default:
+            CRYPTOPP_ASSERT(0);
+        }
+    }
+#else
+    CRYPTOPP_ASSERT(len == 16);
+
+    byte* k = out;
+    if (carry)
+    {
+        k[0] ^= 0x87;
+        return;
+    }
+#endif  // CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS
+}
+
+inline void GF_Double(byte *inout, unsigned int len)
+{
+    GF_Double(inout, inout, len);
+}
+
+ANONYMOUS_NAMESPACE_END
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void XTS_ModeBase::ThrowIfInvalidBlockSize(size_t length)
+{
+#if CRYPTOPP_XTS_WIDE_BLOCK_CIPHERS
+    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
+}
+
+void XTS_ModeBase::ThrowIfInvalidKeyLength(size_t length)
+{
+    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)
+{
+    ThrowIfInvalidKeyLength(length);
+    ThrowIfInvalidBlockSize(BlockSize());
+
+    const size_t klen = length/2;
+    AccessBlockCipher().SetKey(key+0, klen, params);
+    AccessTweakCipher().SetKey(key+klen, klen, params);
+
+    ResizeBuffers();
+
+    size_t ivLength;
+    const byte *iv = GetIVAndThrowIfInvalid(params, ivLength);
+    Resynchronize(iv, (int)ivLength);
+}
+
+void XTS_ModeBase::Resynchronize(const byte *iv, int ivLength)
+{
+    BlockOrientedCipherModeBase::Resynchronize(iv, ivLength);
+    std::memcpy(m_xregister, m_register, ivLength);
+    GetTweakCipher().ProcessBlock(m_xregister);
+}
+
+void XTS_ModeBase::Resynchronize(word64 sector, ByteOrder order)
+{
+    SecByteBlock iv(GetTweakCipher().BlockSize());
+    PutWord<word64>(false, order, iv, sector);
+    std::memset(iv+8, 0x00, iv.size()-8);
+
+    BlockOrientedCipherModeBase::Resynchronize(iv, (int)iv.size());
+    std::memcpy(m_xregister, iv, iv.size());
+    GetTweakCipher().ProcessBlock(m_xregister);
+}
+
+void XTS_ModeBase::ResizeBuffers()
+{
+    BlockOrientedCipherModeBase::ResizeBuffers();
+    m_xworkspace.New(GetBlockCipher().BlockSize()*ParallelBlocks);
+    m_xregister.New(GetBlockCipher().BlockSize()*ParallelBlocks);
+}
+
+// ProcessData runs either 12-4-1 blocks, 8-2-1 or 4-1 blocks. Which is
+// selected depends on ParallelBlocks in the header file. 12-4-1 or 8-2-1
+// can be used on Aarch64 and PowerPC. Intel should use 4-1 due to lack
+// of registers. The unneeded code paths should be removed by optimizer.
+// The extra gyrations save us 1.8 cpb on Aarch64 and 2.1 cpb on PowerPC.
+void XTS_ModeBase::ProcessData(byte *outString, const byte *inString, size_t length)
+{
+    // data unit is multiple of 16 bytes
+    CRYPTOPP_ASSERT(length % BlockSize() == 0);
+
+    enum { lastParallelBlock = ParallelBlocks-1 };
+    const unsigned int blockSize = GetBlockCipher().BlockSize();
+    const size_t parallelSize = blockSize*ParallelBlocks;
+
+    // encrypt the data unit, optimal size at a time
+    while (length >= parallelSize)
+    {
+        // 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);
+        GF_Double(m_xregister+3*blockSize, m_xregister+2*blockSize, blockSize);
+
+        if (ParallelBlocks > 4)
+        {
+            GF_Double(m_xregister+4*blockSize, m_xregister+3*blockSize, blockSize);
+            GF_Double(m_xregister+5*blockSize, m_xregister+4*blockSize, blockSize);
+            GF_Double(m_xregister+6*blockSize, m_xregister+5*blockSize, blockSize);
+            GF_Double(m_xregister+7*blockSize, m_xregister+6*blockSize, blockSize);
+        }
+        if (ParallelBlocks > 8)
+        {
+            GF_Double(m_xregister+8*blockSize, m_xregister+7*blockSize, blockSize);
+            GF_Double(m_xregister+9*blockSize, m_xregister+8*blockSize, blockSize);
+            GF_Double(m_xregister+10*blockSize, m_xregister+9*blockSize, blockSize);
+            GF_Double(m_xregister+11*blockSize, m_xregister+10*blockSize, blockSize);
+        }
+
+        // merge the tweak into the input block
+        XorBuffer(m_xworkspace, inString, m_xregister, parallelSize);
+
+        // encrypt one block, merge the tweak into the output block
+        GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister,
+            outString, parallelSize, BlockTransformation::BT_AllowParallel);
+
+        // m_xregister[0] always points to the next tweak.
+        GF_Double(m_xregister+0, m_xregister+lastParallelBlock*blockSize, blockSize);
+
+        inString += parallelSize;
+        outString += parallelSize;
+        length -= parallelSize;
+    }
+
+    // encrypt the data unit, 4 blocks at a time
+    while (ParallelBlocks == 12 && length >= blockSize*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);
+        GF_Double(m_xregister+3*blockSize, m_xregister+2*blockSize, blockSize);
+
+        // merge the tweak into the input block
+        XorBuffer(m_xworkspace, inString, m_xregister, blockSize*4);
+
+        // encrypt one block, merge the tweak into the output block
+        GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister,
+            outString, blockSize*4, BlockTransformation::BT_AllowParallel);
+
+        // m_xregister[0] always points to the next tweak.
+        GF_Double(m_xregister+0, m_xregister+3*blockSize, blockSize);
+
+        inString += blockSize*4;
+        outString += blockSize*4;
+        length -= blockSize*4;
+    }
+
+    // encrypt the data unit, 2 blocks at a time
+    while (ParallelBlocks == 8 && length >= blockSize*2)
+    {
+        // m_xregister[0] always points to the next tweak.
+        GF_Double(m_xregister+1*blockSize, m_xregister+0*blockSize, blockSize);
+
+        // merge the tweak into the input block
+        XorBuffer(m_xworkspace, inString, m_xregister, blockSize*2);
+
+        // encrypt one block, merge the tweak into the output block
+        GetBlockCipher().AdvancedProcessBlocks(m_xworkspace, m_xregister,
+            outString, blockSize*2, BlockTransformation::BT_AllowParallel);
+
+        // m_xregister[0] always points to the next tweak.
+        GF_Double(m_xregister+0, m_xregister+1*blockSize, blockSize);
+
+        inString += blockSize*2;
+        outString += blockSize*2;
+        length -= blockSize*2;
+    }
+
+    // encrypt the data unit, blocksize at a time
+    while (length)
+    {
+        // merge the tweak into the input block
+        XorBuffer(m_xworkspace, inString, m_xregister, blockSize);
+
+        // encrypt one block
+        GetBlockCipher().ProcessBlock(m_xworkspace);
+
+        // merge the tweak into the output block
+        XorBuffer(outString, m_xworkspace, m_xregister, blockSize);
+
+        // Multiply T by alpha
+        GF_Double(m_xregister, blockSize);
+
+        inString += blockSize;
+        outString += blockSize;
+        length -= blockSize;
+    }
+}
+
+size_t XTS_ModeBase::ProcessLastBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)
+{
+    // need at least a full AES block
+    CRYPTOPP_ASSERT(inLength >= BlockSize());
+
+    if (inLength < BlockSize())
+        throw InvalidArgument("XTS: message is too short for ciphertext stealing");
+
+    if (IsForwardTransformation())
+        return ProcessLastPlainBlock(outString, outLength, inString, inLength);
+    else
+        return ProcessLastCipherBlock(outString, outLength, inString, inLength);
+}
+
+size_t XTS_ModeBase::ProcessLastPlainBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)
+{
+    // ensure output buffer is large enough
+    CRYPTOPP_ASSERT(outLength >= inLength);
+
+    const unsigned int blockSize = GetBlockCipher().BlockSize();
+    const size_t blocks = inLength / blockSize;
+    const size_t tail = inLength % blockSize;
+    outLength = inLength;
+
+    if (tail == 0)
+    {
+        // Allow ProcessData to handle all the full blocks
+        ProcessData(outString, inString, inLength);
+        return inLength;
+    }
+    else if (blocks > 1)
+    {
+        // Allow ProcessData to handle full blocks except one
+        const size_t head = (blocks-1)*blockSize;
+        ProcessData(outString, inString, inLength-head);
+
+        outString += head;
+        inString  += head; inLength -= head;
+    }
+
+    ///// handle the full block /////
+
+    // merge the tweak into the input block
+    XorBuffer(m_xworkspace, inString, m_xregister, blockSize);
+
+    // encrypt one block
+    GetBlockCipher().ProcessBlock(m_xworkspace);
+
+    // merge the tweak into the output block
+    XorBuffer(outString, m_xworkspace, m_xregister, blockSize);
+
+    // Multiply T by alpha
+    GF_Double(m_xregister, blockSize);
+
+    ///// handle final partial block /////
+
+    inString += blockSize;
+    outString += blockSize;
+    const size_t len = inLength-blockSize;
+
+    // copy in the final plaintext bytes
+    std::memcpy(m_xworkspace, inString, len);
+    // and copy out the final ciphertext bytes
+    std::memcpy(outString, outString-blockSize, len);
+    // "steal" ciphertext to complete the block
+    std::memcpy(m_xworkspace+len, outString-blockSize+len, blockSize-len);
+
+    // merge the tweak into the input block
+    XorBuffer(m_xworkspace, m_xregister, blockSize);
+
+    // encrypt one block
+    GetBlockCipher().ProcessBlock(m_xworkspace);
+
+    // merge the tweak into the previous output block
+    XorBuffer(outString-blockSize, m_xworkspace, m_xregister, blockSize);
+
+    return outLength;
+}
+
+size_t XTS_ModeBase::ProcessLastCipherBlock(byte *outString, size_t outLength, const byte *inString, size_t inLength)
+{
+    // ensure output buffer is large enough
+    CRYPTOPP_ASSERT(outLength >= inLength);
+
+    const unsigned int blockSize = GetBlockCipher().BlockSize();
+    const size_t blocks = inLength / blockSize;
+    const size_t tail = inLength % blockSize;
+    outLength = inLength;
+
+    if (tail == 0)
+    {
+        // Allow ProcessData to handle all the full blocks
+        ProcessData(outString, inString, inLength);
+        return inLength;
+    }
+    else if (blocks > 1)
+    {
+        // Allow ProcessData to handle full blocks except one
+        const size_t head = (blocks-1)*blockSize;
+        ProcessData(outString, inString, inLength-head);
+
+        outString += head;
+        inString  += head; inLength -= head;
+    }
+
+    #define poly1 (m_xregister+0*blockSize)
+    #define poly2 (m_xregister+1*blockSize)
+    GF_Double(poly2, poly1, blockSize);
+
+    ///// handle final partial block /////
+
+    inString += blockSize;
+    outString += blockSize;
+    const size_t len = inLength-blockSize;
+
+    // merge the tweak into the input block
+    XorBuffer(m_xworkspace, inString-blockSize, poly2, blockSize);
+
+    // encrypt one block
+    GetBlockCipher().ProcessBlock(m_xworkspace);
+
+    // merge the tweak into the output block
+    XorBuffer(m_xworkspace, poly2, blockSize);
+
+    // copy in the final plaintext bytes
+    std::memcpy(outString-blockSize, inString, len);
+    // and copy out the final ciphertext bytes
+    std::memcpy(outString, m_xworkspace, len);
+    // "steal" ciphertext to complete the block
+    std::memcpy(outString-blockSize+len, m_xworkspace+len, blockSize-len);
+
+    ///// handle the full previous block /////
+
+    inString -= blockSize;
+    outString -= blockSize;
+
+    // merge the tweak into the input block
+    XorBuffer(m_xworkspace, outString, poly1, blockSize);
+
+    // encrypt one block
+    GetBlockCipher().ProcessBlock(m_xworkspace);
+
+    // merge the tweak into the output block
+    XorBuffer(outString, m_xworkspace, poly1, blockSize);
+
+    return outLength;
+}
+
+NAMESPACE_END