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59 lines
1.5 KiB
59 lines
1.5 KiB
// eax.cpp - written and placed in the public domain by Wei Dai |
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#include "pch.h" |
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#include "eax.h" |
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NAMESPACE_BEGIN(CryptoPP) |
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void EAX_Base::SetKeyWithoutResync(const byte *userKey, size_t keylength, const NameValuePairs ¶ms) |
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{ |
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AccessMAC().SetKey(userKey, keylength, params); |
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m_buffer.New(2*AccessMAC().TagSize()); |
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} |
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void EAX_Base::Resync(const byte *iv, size_t len) |
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{ |
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MessageAuthenticationCode &mac = AccessMAC(); |
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unsigned int blockSize = mac.TagSize(); |
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memset(m_buffer, 0, blockSize); |
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mac.Update(m_buffer, blockSize); |
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mac.CalculateDigest(m_buffer+blockSize, iv, len); |
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m_buffer[blockSize-1] = 1; |
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mac.Update(m_buffer, blockSize); |
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m_ctr.SetCipherWithIV(AccessMAC().AccessCipher(), m_buffer+blockSize, blockSize); |
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} |
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size_t EAX_Base::AuthenticateBlocks(const byte *data, size_t len) |
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{ |
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AccessMAC().Update(data, len); |
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return 0; |
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} |
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void EAX_Base::AuthenticateLastHeaderBlock() |
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{ |
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assert(m_bufferedDataLength == 0); |
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MessageAuthenticationCode &mac = AccessMAC(); |
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unsigned int blockSize = mac.TagSize(); |
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mac.Final(m_buffer); |
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xorbuf(m_buffer+blockSize, m_buffer, blockSize); |
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memset(m_buffer, 0, blockSize); |
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m_buffer[blockSize-1] = 2; |
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mac.Update(m_buffer, blockSize); |
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} |
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void EAX_Base::AuthenticateLastFooterBlock(byte *tag, size_t macSize) |
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{ |
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assert(m_bufferedDataLength == 0); |
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MessageAuthenticationCode &mac = AccessMAC(); |
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unsigned int blockSize = mac.TagSize(); |
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mac.TruncatedFinal(m_buffer, macSize); |
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xorbuf(tag, m_buffer, m_buffer+blockSize, macSize); |
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} |
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NAMESPACE_END
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