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569 lines
19 KiB
569 lines
19 KiB
![]()
4 years ago
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// chacha.cpp - written and placed in the public domain by Jeffrey Walton.
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// Based on Wei Dai's Salsa20, Botan's SSE2 implementation,
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// and Bernstein's reference ChaCha family implementation at
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// http://cr.yp.to/chacha.html.
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#include "pch.h"
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#include "config.h"
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#include "chacha.h"
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#include "argnames.h"
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#include "misc.h"
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#include "cpu.h"
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// Internal compiler error in GCC 3.3 and below
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#if defined(__GNUC__) && (__GNUC__ < 4)
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# undef CRYPTOPP_SSE2_INTRIN_AVAILABLE
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#endif
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NAMESPACE_BEGIN(CryptoPP)
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#if (CRYPTOPP_ARM_NEON_AVAILABLE)
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extern void ChaCha_OperateKeystream_NEON(const word32 *state, const byte* input, byte *output, unsigned int rounds);
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#endif
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#if (CRYPTOPP_AVX2_AVAILABLE)
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extern void ChaCha_OperateKeystream_AVX2(const word32 *state, const byte* input, byte *output, unsigned int rounds);
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#endif
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#if (CRYPTOPP_SSE2_INTRIN_AVAILABLE)
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extern void ChaCha_OperateKeystream_SSE2(const word32 *state, const byte* input, byte *output, unsigned int rounds);
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#endif
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#if (CRYPTOPP_ALTIVEC_AVAILABLE)
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extern void ChaCha_OperateKeystream_ALTIVEC(const word32 *state, const byte* input, byte *output, unsigned int rounds);
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#endif
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#if defined(CRYPTOPP_DEBUG) && !defined(CRYPTOPP_DOXYGEN_PROCESSING)
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void ChaCha_TestInstantiations()
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{
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ChaCha::Encryption x;
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ChaChaTLS::Encryption y;
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XChaCha20::Encryption z;
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}
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#endif
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NAMESPACE_END // CryptoPP
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////////////////////////////// ChaCha Core //////////////////////////////
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#define CHACHA_QUARTER_ROUND(a,b,c,d) \
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a += b; d ^= a; d = rotlConstant<16,word32>(d); \
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c += d; b ^= c; b = rotlConstant<12,word32>(b); \
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a += b; d ^= a; d = rotlConstant<8,word32>(d); \
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c += d; b ^= c; b = rotlConstant<7,word32>(b);
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#define CHACHA_OUTPUT(x){\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 0, x0 + state[0]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 1, x1 + state[1]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 2, x2 + state[2]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 3, x3 + state[3]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 4, x4 + state[4]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 5, x5 + state[5]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 6, x6 + state[6]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 7, x7 + state[7]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 8, x8 + state[8]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 9, x9 + state[9]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 10, x10 + state[10]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 11, x11 + state[11]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 12, x12 + state[12]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 13, x13 + state[13]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 14, x14 + state[14]);\
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CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, LITTLE_ENDIAN_ORDER, 15, x15 + state[15]);}
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ANONYMOUS_NAMESPACE_BEGIN
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// Hacks... Bring in all symbols, and supply
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// the stuff the templates normally provide.
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using namespace CryptoPP;
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typedef word32 WordType;
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enum {BYTES_PER_ITERATION=64};
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// MultiBlockSafe detects a condition that can arise in the SIMD
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// implementations where we overflow one of the 32-bit state words during
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// addition in an intermediate result. Preconditions for the issue include
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// a user seeks to around 2^32 blocks (256 GB of data) for ChaCha; or a
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// user specifies an arbitrarily large initial counter block for ChaChaTLS.
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// Also see https://github.com/weidai11/cryptopp/issues/732.
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inline bool MultiBlockSafe(unsigned int ctrLow, unsigned int blocks)
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{
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return 0xffffffff - ctrLow > blocks;
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}
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// OperateKeystream always produces a key stream. The key stream is written
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// to output. Optionally a message may be supplied to xor with the key stream.
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// The message is input, and output = output ^ input.
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void ChaCha_OperateKeystream(KeystreamOperation operation,
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word32 state[16], word32& ctrLow, word32& ctrHigh, word32 rounds,
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byte *output, const byte *input, size_t iterationCount)
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{
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do
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{
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#if (CRYPTOPP_AVX2_AVAILABLE)
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if (HasAVX2())
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{
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while (iterationCount >= 8 && MultiBlockSafe(state[12], 8))
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{
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const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
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ChaCha_OperateKeystream_AVX2(state, xorInput ? input : NULLPTR, output, rounds);
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// MultiBlockSafe avoids overflow on the counter words
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state[12] += 8;
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input += (!!xorInput) * 8 * BYTES_PER_ITERATION;
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output += 8 * BYTES_PER_ITERATION;
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iterationCount -= 8;
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}
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}
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#endif
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#if (CRYPTOPP_SSE2_INTRIN_AVAILABLE)
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if (HasSSE2())
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{
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while (iterationCount >= 4 && MultiBlockSafe(state[12], 4))
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{
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const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
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ChaCha_OperateKeystream_SSE2(state, xorInput ? input : NULLPTR, output, rounds);
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// MultiBlockSafe avoids overflow on the counter words
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state[12] += 4;
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input += (!!xorInput)*4*BYTES_PER_ITERATION;
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output += 4*BYTES_PER_ITERATION;
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iterationCount -= 4;
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}
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}
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#endif
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#if (CRYPTOPP_ARM_NEON_AVAILABLE)
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if (HasNEON())
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{
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while (iterationCount >= 4 && MultiBlockSafe(state[12], 4))
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{
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const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
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ChaCha_OperateKeystream_NEON(state, xorInput ? input : NULLPTR, output, rounds);
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// MultiBlockSafe avoids overflow on the counter words
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state[12] += 4;
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input += (!!xorInput)*4*BYTES_PER_ITERATION;
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output += 4*BYTES_PER_ITERATION;
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iterationCount -= 4;
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}
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}
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#endif
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#if (CRYPTOPP_ALTIVEC_AVAILABLE)
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if (HasAltivec())
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{
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while (iterationCount >= 4 && MultiBlockSafe(state[12], 4))
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{
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const bool xorInput = (operation & INPUT_NULL) != INPUT_NULL;
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ChaCha_OperateKeystream_ALTIVEC(state, xorInput ? input : NULLPTR, output, rounds);
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// MultiBlockSafe avoids overflow on the counter words
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state[12] += 4;
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input += (!!xorInput)*4*BYTES_PER_ITERATION;
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output += 4*BYTES_PER_ITERATION;
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iterationCount -= 4;
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}
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}
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#endif
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if (iterationCount)
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{
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word32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
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x0 = state[0]; x1 = state[1]; x2 = state[2]; x3 = state[3];
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x4 = state[4]; x5 = state[5]; x6 = state[6]; x7 = state[7];
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x8 = state[8]; x9 = state[9]; x10 = state[10]; x11 = state[11];
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x12 = state[12]; x13 = state[13]; x14 = state[14]; x15 = state[15];
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for (int i = static_cast<int>(rounds); i > 0; i -= 2)
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{
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CHACHA_QUARTER_ROUND(x0, x4, x8, x12);
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CHACHA_QUARTER_ROUND(x1, x5, x9, x13);
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CHACHA_QUARTER_ROUND(x2, x6, x10, x14);
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CHACHA_QUARTER_ROUND(x3, x7, x11, x15);
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CHACHA_QUARTER_ROUND(x0, x5, x10, x15);
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CHACHA_QUARTER_ROUND(x1, x6, x11, x12);
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CHACHA_QUARTER_ROUND(x2, x7, x8, x13);
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CHACHA_QUARTER_ROUND(x3, x4, x9, x14);
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}
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CRYPTOPP_KEYSTREAM_OUTPUT_SWITCH(CHACHA_OUTPUT, BYTES_PER_ITERATION);
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// This is state[12] and state[13] from ChaCha. In the case of
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// ChaChaTLS ctrHigh is a reference to a discard value.
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if (++ctrLow == 0)
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ctrHigh++;
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}
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// We may re-enter a SIMD keystream operation from here.
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} while (iterationCount--);
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}
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// XChaCha key derivation
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void HChaCha_OperateKeystream(const word32 state[16], word32 output[8])
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{
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word32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
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x0 = state[0]; x1 = state[1]; x2 = state[2]; x3 = state[3];
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x4 = state[4]; x5 = state[5]; x6 = state[6]; x7 = state[7];
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x8 = state[8]; x9 = state[9]; x10 = state[10]; x11 = state[11];
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x12 = state[12]; x13 = state[13]; x14 = state[14]; x15 = state[15];
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for (int i = 20; i > 0; i -= 2)
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{
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CHACHA_QUARTER_ROUND(x0, x4, x8, x12);
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CHACHA_QUARTER_ROUND(x1, x5, x9, x13);
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CHACHA_QUARTER_ROUND(x2, x6, x10, x14);
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CHACHA_QUARTER_ROUND(x3, x7, x11, x15);
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CHACHA_QUARTER_ROUND(x0, x5, x10, x15);
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CHACHA_QUARTER_ROUND(x1, x6, x11, x12);
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CHACHA_QUARTER_ROUND(x2, x7, x8, x13);
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CHACHA_QUARTER_ROUND(x3, x4, x9, x14);
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}
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output[0] = x0; output[1] = x1;
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output[2] = x2; output[3] = x3;
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output[4] = x12; output[5] = x13;
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output[6] = x14; output[7] = x15;
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}
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std::string ChaCha_AlgorithmProvider()
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{
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#if (CRYPTOPP_AVX2_AVAILABLE)
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if (HasAVX2())
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return "AVX2";
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else
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#endif
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#if (CRYPTOPP_SSE2_INTRIN_AVAILABLE)
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if (HasSSE2())
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return "SSE2";
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else
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#endif
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#if (CRYPTOPP_ARM_NEON_AVAILABLE)
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if (HasNEON())
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return "NEON";
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else
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#endif
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#if (CRYPTOPP_ALTIVEC_AVAILABLE)
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if (HasAltivec())
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return "Altivec";
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else
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#endif
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return "C++";
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}
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unsigned int ChaCha_GetAlignment()
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{
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#if (CRYPTOPP_AVX2_AVAILABLE)
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if (HasAVX2())
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return 16;
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else
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#endif
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#if (CRYPTOPP_SSE2_INTRIN_AVAILABLE)
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if (HasSSE2())
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return 16;
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else
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#endif
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#if (CRYPTOPP_ALTIVEC_AVAILABLE)
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if (HasAltivec())
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return 16;
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else
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#endif
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return GetAlignmentOf<word32>();
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}
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unsigned int ChaCha_GetOptimalBlockSize()
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{
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#if (CRYPTOPP_AVX2_AVAILABLE)
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if (HasAVX2())
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return 8 * BYTES_PER_ITERATION;
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else
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#endif
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#if (CRYPTOPP_SSE2_INTRIN_AVAILABLE)
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if (HasSSE2())
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return 4*BYTES_PER_ITERATION;
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else
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#endif
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#if (CRYPTOPP_ARM_NEON_AVAILABLE)
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if (HasNEON())
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return 4*BYTES_PER_ITERATION;
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else
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#endif
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#if (CRYPTOPP_ALTIVEC_AVAILABLE)
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if (HasAltivec())
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return 4*BYTES_PER_ITERATION;
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else
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#endif
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return BYTES_PER_ITERATION;
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}
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ANONYMOUS_NAMESPACE_END
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NAMESPACE_BEGIN(CryptoPP)
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////////////////////////////// Bernstein ChaCha //////////////////////////////
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std::string ChaCha_Policy::AlgorithmName() const
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{
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return std::string("ChaCha")+IntToString(m_rounds);
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}
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std::string ChaCha_Policy::AlgorithmProvider() const
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{
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return ChaCha_AlgorithmProvider();
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}
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void ChaCha_Policy::CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length)
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{
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CRYPTOPP_ASSERT(key); CRYPTOPP_ASSERT(length == 16 || length == 32);
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CRYPTOPP_UNUSED(key); CRYPTOPP_UNUSED(length);
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// Use previous rounds as the default value
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int rounds = params.GetIntValueWithDefault(Name::Rounds(), m_rounds);
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if (rounds != 20 && rounds != 12 && rounds != 8)
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throw InvalidRounds(ChaCha::StaticAlgorithmName(), rounds);
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// Latch a good value
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m_rounds = rounds;
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// "expand 16-byte k" or "expand 32-byte k"
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m_state[0] = 0x61707865;
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m_state[1] = (length == 16) ? 0x3120646e : 0x3320646e;
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m_state[2] = (length == 16) ? 0x79622d36 : 0x79622d32;
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m_state[3] = 0x6b206574;
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GetBlock<word32, LittleEndian> get1(key);
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get1(m_state[4])(m_state[5])(m_state[6])(m_state[7]);
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GetBlock<word32, LittleEndian> get2(key + ((length == 32) ? 16 : 0));
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get2(m_state[8])(m_state[9])(m_state[10])(m_state[11]);
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}
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void ChaCha_Policy::CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length)
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{
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CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
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CRYPTOPP_ASSERT(length==8); CRYPTOPP_UNUSED(length);
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GetBlock<word32, LittleEndian> get(IV);
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m_state[12] = m_state[13] = 0;
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get(m_state[14])(m_state[15]);
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}
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void ChaCha_Policy::SeekToIteration(lword iterationCount)
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{
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m_state[12] = (word32)iterationCount; // low word
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m_state[13] = (word32)SafeRightShift<32>(iterationCount);
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}
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||
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unsigned int ChaCha_Policy::GetAlignment() const
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{
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return ChaCha_GetAlignment();
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}
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unsigned int ChaCha_Policy::GetOptimalBlockSize() const
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||
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{
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return ChaCha_GetOptimalBlockSize();
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||
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}
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||
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||
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void ChaCha_Policy::OperateKeystream(KeystreamOperation operation,
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||
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byte *output, const byte *input, size_t iterationCount)
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||
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{
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||
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ChaCha_OperateKeystream(operation, m_state, m_state[12], m_state[13],
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m_rounds, output, input, iterationCount);
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||
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}
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||
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||
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////////////////////////////// IETF ChaChaTLS //////////////////////////////
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||
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||
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std::string ChaChaTLS_Policy::AlgorithmName() const
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||
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{
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||
|
return std::string("ChaChaTLS");
|
||
|
}
|
||
|
|
||
|
std::string ChaChaTLS_Policy::AlgorithmProvider() const
|
||
|
{
|
||
|
return ChaCha_AlgorithmProvider();
|
||
|
}
|
||
|
|
||
|
void ChaChaTLS_Policy::CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length)
|
||
|
{
|
||
|
CRYPTOPP_ASSERT(key); CRYPTOPP_ASSERT(length == 32);
|
||
|
CRYPTOPP_UNUSED(length);
|
||
|
|
||
|
// ChaChaTLS is always 20 rounds. Fetch Rounds() to avoid a spurious failure.
|
||
|
int rounds = params.GetIntValueWithDefault(Name::Rounds(), ROUNDS);
|
||
|
if (rounds != 20)
|
||
|
throw InvalidRounds(ChaChaTLS::StaticAlgorithmName(), rounds);
|
||
|
|
||
|
// RFC 8439 test vectors use an initial block counter. However, the counter
|
||
|
// can be an arbitrary value per RFC 8439 Section 2.4. We stash the counter
|
||
|
// away in state[16] and use it for a Resynchronize() operation. I think
|
||
|
// the initial counter is used more like a Tweak when non-0, and it should
|
||
|
// be provided in Resynchronize() (light-weight re-keying). However,
|
||
|
// Resynchronize() does not have an overload that allows us to pass it into
|
||
|
// the function, so we have to use the heavier-weight SetKey to change it.
|
||
|
word64 block;
|
||
|
if (params.GetValue("InitialBlock", block))
|
||
|
m_counter = static_cast<word32>(block);
|
||
|
else
|
||
|
m_counter = 0;
|
||
|
|
||
|
// State words are defined in RFC 8439, Section 2.3. Key is 32-bytes.
|
||
|
GetBlock<word32, LittleEndian> get(key);
|
||
|
get(m_state[KEY+0])(m_state[KEY+1])(m_state[KEY+2])(m_state[KEY+3])
|
||
|
(m_state[KEY+4])(m_state[KEY+5])(m_state[KEY+6])(m_state[KEY+7]);
|
||
|
}
|
||
|
|
||
|
void ChaChaTLS_Policy::CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length)
|
||
|
{
|
||
|
CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
|
||
|
CRYPTOPP_ASSERT(length==12);
|
||
|
|
||
|
// State words are defined in RFC 8439, Section 2.3.
|
||
|
m_state[0] = 0x61707865; m_state[1] = 0x3320646e;
|
||
|
m_state[2] = 0x79622d32; m_state[3] = 0x6b206574;
|
||
|
|
||
|
// Copy saved key into state
|
||
|
std::memcpy(m_state+4, m_state+KEY, 8*sizeof(word32));
|
||
|
|
||
|
// State words are defined in RFC 8439, Section 2.3
|
||
|
GetBlock<word32, LittleEndian> get(IV);
|
||
|
m_state[12] = m_counter;
|
||
|
get(m_state[13])(m_state[14])(m_state[15]);
|
||
|
}
|
||
|
|
||
|
void ChaChaTLS_Policy::SeekToIteration(lword iterationCount)
|
||
|
{
|
||
|
// Should we throw here??? If the initial block counter is
|
||
|
// large then we can wrap and process more data as long as
|
||
|
// data processed in the security context does not exceed
|
||
|
// 2^32 blocks or approximately 256 GB of data.
|
||
|
CRYPTOPP_ASSERT(iterationCount <= std::numeric_limits<word32>::max());
|
||
|
m_state[12] = (word32)iterationCount; // low word
|
||
|
}
|
||
|
|
||
|
unsigned int ChaChaTLS_Policy::GetAlignment() const
|
||
|
{
|
||
|
return ChaCha_GetAlignment();
|
||
|
}
|
||
|
|
||
|
unsigned int ChaChaTLS_Policy::GetOptimalBlockSize() const
|
||
|
{
|
||
|
return ChaCha_GetOptimalBlockSize();
|
||
|
}
|
||
|
|
||
|
void ChaChaTLS_Policy::OperateKeystream(KeystreamOperation operation,
|
||
|
byte *output, const byte *input, size_t iterationCount)
|
||
|
{
|
||
|
word32 discard=0;
|
||
|
ChaCha_OperateKeystream(operation, m_state, m_state[12], discard,
|
||
|
ROUNDS, output, input, iterationCount);
|
||
|
|
||
|
// If this fires it means ChaCha_OperateKeystream generated a counter
|
||
|
// block carry that was discarded. The problem is, the RFC does not
|
||
|
// specify what should happen when the counter block wraps. All we can
|
||
|
// do is inform the user that something bad may happen because we don't
|
||
|
// know what we should do.
|
||
|
// Also see https://github.com/weidai11/cryptopp/issues/790 and
|
||
|
// https://mailarchive.ietf.org/arch/msg/cfrg/gsOnTJzcbgG6OqD8Sc0GO5aR_tU
|
||
|
// CRYPTOPP_ASSERT(discard==0);
|
||
|
}
|
||
|
|
||
|
////////////////////////////// IETF XChaCha20 //////////////////////////////
|
||
|
|
||
|
std::string XChaCha20_Policy::AlgorithmName() const
|
||
|
{
|
||
|
return std::string("XChaCha20");
|
||
|
}
|
||
|
|
||
|
std::string XChaCha20_Policy::AlgorithmProvider() const
|
||
|
{
|
||
|
return ChaCha_AlgorithmProvider();
|
||
|
}
|
||
|
|
||
|
void XChaCha20_Policy::CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length)
|
||
|
{
|
||
|
CRYPTOPP_ASSERT(key); CRYPTOPP_ASSERT(length == 32);
|
||
|
CRYPTOPP_UNUSED(length);
|
||
|
|
||
|
// Use previous rounds as the default value
|
||
|
int rounds = params.GetIntValueWithDefault(Name::Rounds(), m_rounds);
|
||
|
if (rounds != 20 && rounds != 12)
|
||
|
throw InvalidRounds(ChaCha::StaticAlgorithmName(), rounds);
|
||
|
|
||
|
// Latch a good value
|
||
|
m_rounds = rounds;
|
||
|
|
||
|
word64 block;
|
||
|
if (params.GetValue("InitialBlock", block))
|
||
|
m_counter = static_cast<word32>(block);
|
||
|
else
|
||
|
m_counter = 1;
|
||
|
|
||
|
// Stash key away for use in CipherResynchronize
|
||
|
GetBlock<word32, LittleEndian> get(key);
|
||
|
get(m_state[KEY+0])(m_state[KEY+1])(m_state[KEY+2])(m_state[KEY+3])
|
||
|
(m_state[KEY+4])(m_state[KEY+5])(m_state[KEY+6])(m_state[KEY+7]);
|
||
|
}
|
||
|
|
||
|
void XChaCha20_Policy::CipherResynchronize(byte *keystreamBuffer, const byte *iv, size_t length)
|
||
|
{
|
||
|
CRYPTOPP_UNUSED(keystreamBuffer), CRYPTOPP_UNUSED(length);
|
||
|
CRYPTOPP_ASSERT(length==24);
|
||
|
|
||
|
// HChaCha derivation
|
||
|
m_state[0] = 0x61707865; m_state[1] = 0x3320646e;
|
||
|
m_state[2] = 0x79622d32; m_state[3] = 0x6b206574;
|
||
|
|
||
|
// Copy saved key into state
|
||
|
std::memcpy(m_state+4, m_state+KEY, 8*sizeof(word32));
|
||
|
|
||
|
GetBlock<word32, LittleEndian> get(iv);
|
||
|
get(m_state[12])(m_state[13])(m_state[14])(m_state[15]);
|
||
|
|
||
|
// Operate the keystream without adding state back in.
|
||
|
// This function also gathers the key words into a
|
||
|
// contiguous 8-word block.
|
||
|
HChaCha_OperateKeystream(m_state, m_state+4);
|
||
|
|
||
|
// XChaCha state
|
||
|
m_state[0] = 0x61707865; m_state[1] = 0x3320646e;
|
||
|
m_state[2] = 0x79622d32; m_state[3] = 0x6b206574;
|
||
|
|
||
|
// Setup new IV
|
||
|
m_state[12] = m_counter;
|
||
|
m_state[13] = 0;
|
||
|
m_state[14] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, iv+16);
|
||
|
m_state[15] = GetWord<word32>(false, LITTLE_ENDIAN_ORDER, iv+20);
|
||
|
}
|
||
|
|
||
|
void XChaCha20_Policy::SeekToIteration(lword iterationCount)
|
||
|
{
|
||
|
// Should we throw here??? XChaCha does not have a block
|
||
|
// counter, so I'm not sure how to seek on it.
|
||
|
CRYPTOPP_ASSERT(0); CRYPTOPP_UNUSED(iterationCount);
|
||
|
}
|
||
|
|
||
|
unsigned int XChaCha20_Policy::GetAlignment() const
|
||
|
{
|
||
|
return ChaCha_GetAlignment();
|
||
|
}
|
||
|
|
||
|
unsigned int XChaCha20_Policy::GetOptimalBlockSize() const
|
||
|
{
|
||
|
return ChaCha_GetOptimalBlockSize();
|
||
|
}
|
||
|
|
||
|
void XChaCha20_Policy::OperateKeystream(KeystreamOperation operation,
|
||
|
byte *output, const byte *input, size_t iterationCount)
|
||
|
{
|
||
|
ChaCha_OperateKeystream(operation, m_state, m_state[12], m_state[13],
|
||
|
m_rounds, output, input, iterationCount);
|
||
|
}
|
||
|
|
||
|
NAMESPACE_END
|