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Diffstat (limited to 'src-cryptopp/pkcspad.cpp')
| -rw-r--r-- | src-cryptopp/pkcspad.cpp | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/src-cryptopp/pkcspad.cpp b/src-cryptopp/pkcspad.cpp new file mode 100644 index 0000000..e1f1d1e --- /dev/null +++ b/src-cryptopp/pkcspad.cpp @@ -0,0 +1,124 @@ +// pkcspad.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_PKCSPAD_CPP // SunCC workaround: compiler could cause this file to be included twice +#define CRYPTOPP_PKCSPAD_CPP + +#include "pkcspad.h" +#include <assert.h> + +NAMESPACE_BEGIN(CryptoPP) + +// more in dll.cpp +template<> const byte PKCS_DigestDecoration<Weak1::MD2>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,0x04,0x10}; +template<> const unsigned int PKCS_DigestDecoration<Weak1::MD2>::length = sizeof(PKCS_DigestDecoration<Weak1::MD2>::decoration); + +template<> const byte PKCS_DigestDecoration<Weak1::MD5>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,0x04,0x10}; +template<> const unsigned int PKCS_DigestDecoration<Weak1::MD5>::length = sizeof(PKCS_DigestDecoration<Weak1::MD5>::decoration); + +template<> const byte PKCS_DigestDecoration<RIPEMD160>::decoration[] = {0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x24,0x03,0x02,0x01,0x05,0x00,0x04,0x14}; +template<> const unsigned int PKCS_DigestDecoration<RIPEMD160>::length = sizeof(PKCS_DigestDecoration<RIPEMD160>::decoration); + +template<> const byte PKCS_DigestDecoration<Tiger>::decoration[] = {0x30,0x29,0x30,0x0D,0x06,0x09,0x2B,0x06,0x01,0x04,0x01,0xDA,0x47,0x0C,0x02,0x05,0x00,0x04,0x18}; +template<> const unsigned int PKCS_DigestDecoration<Tiger>::length = sizeof(PKCS_DigestDecoration<Tiger>::decoration); + +size_t PKCS_EncryptionPaddingScheme::MaxUnpaddedLength(size_t paddedLength) const +{ + return SaturatingSubtract(paddedLength/8, 10U); +} + +void PKCS_EncryptionPaddingScheme::Pad(RandomNumberGenerator &rng, const byte *input, size_t inputLen, byte *pkcsBlock, size_t pkcsBlockLen, const NameValuePairs ¶meters) const +{ + assert (inputLen <= MaxUnpaddedLength(pkcsBlockLen)); // this should be checked by caller + + // convert from bit length to byte length + if (pkcsBlockLen % 8 != 0) + { + pkcsBlock[0] = 0; + pkcsBlock++; + } + pkcsBlockLen /= 8; + + pkcsBlock[0] = 2; // block type 2 + + // pad with non-zero random bytes + for (unsigned i = 1; i < pkcsBlockLen-inputLen-1; i++) + pkcsBlock[i] = (byte)rng.GenerateWord32(1, 0xff); + + pkcsBlock[pkcsBlockLen-inputLen-1] = 0; // separator + memcpy(pkcsBlock+pkcsBlockLen-inputLen, input, inputLen); +} + +DecodingResult PKCS_EncryptionPaddingScheme::Unpad(const byte *pkcsBlock, size_t pkcsBlockLen, byte *output, const NameValuePairs ¶meters) const +{ + bool invalid = false; + size_t maxOutputLen = MaxUnpaddedLength(pkcsBlockLen); + + // convert from bit length to byte length + if (pkcsBlockLen % 8 != 0) + { + invalid = (pkcsBlock[0] != 0) || invalid; + pkcsBlock++; + } + pkcsBlockLen /= 8; + + // Require block type 2. + invalid = (pkcsBlock[0] != 2) || invalid; + + // skip past the padding until we find the separator + size_t i=1; + while (i<pkcsBlockLen && pkcsBlock[i++]) { // null body + } + assert(i==pkcsBlockLen || pkcsBlock[i-1]==0); + + size_t outputLen = pkcsBlockLen - i; + invalid = (outputLen > maxOutputLen) || invalid; + + if (invalid) + return DecodingResult(); + + memcpy (output, pkcsBlock+i, outputLen); + return DecodingResult(outputLen); +} + +// ******************************************************** + +#ifndef CRYPTOPP_IMPORTS + +void PKCS1v15_SignatureMessageEncodingMethod::ComputeMessageRepresentative(RandomNumberGenerator &rng, + const byte *recoverableMessage, size_t recoverableMessageLength, + HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty, + byte *representative, size_t representativeBitLength) const +{ + assert(representativeBitLength >= MinRepresentativeBitLength(hashIdentifier.second, hash.DigestSize())); + + size_t pkcsBlockLen = representativeBitLength; + // convert from bit length to byte length + if (pkcsBlockLen % 8 != 0) + { + representative[0] = 0; + representative++; + } + pkcsBlockLen /= 8; + + representative[0] = 1; // block type 1 + + unsigned int digestSize = hash.DigestSize(); + byte *pPadding = representative + 1; + byte *pDigest = representative + pkcsBlockLen - digestSize; + byte *pHashId = pDigest - hashIdentifier.second; + byte *pSeparator = pHashId - 1; + + // pad with 0xff + memset(pPadding, 0xff, pSeparator-pPadding); + *pSeparator = 0; + memcpy(pHashId, hashIdentifier.first, hashIdentifier.second); + hash.Final(pDigest); +} + +#endif + +NAMESPACE_END + +#endif |