diff options
| author | Vadim Dashevskiy <watcherhd@gmail.com> | 2012-05-15 10:38:20 +0000 |
|---|---|---|
| committer | Vadim Dashevskiy <watcherhd@gmail.com> | 2012-05-15 10:38:20 +0000 |
| commit | 48540940b6c28bb4378abfeb500ec45a625b37b6 (patch) | |
| tree | 2ef294c0763e802f91d868bdef4229b6868527de /plugins/CryptoPP/crypto/oaep.cpp | |
| parent | 5c350913f011e119127baeb32a6aedeb4f0d33bc (diff) | |
initial commit
git-svn-id: http://svn.miranda-ng.org/main/trunk@2 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Diffstat (limited to 'plugins/CryptoPP/crypto/oaep.cpp')
| -rw-r--r-- | plugins/CryptoPP/crypto/oaep.cpp | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/plugins/CryptoPP/crypto/oaep.cpp b/plugins/CryptoPP/crypto/oaep.cpp new file mode 100644 index 0000000000..cbdef84d74 --- /dev/null +++ b/plugins/CryptoPP/crypto/oaep.cpp @@ -0,0 +1,97 @@ +// oaep.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+
+#ifndef CRYPTOPP_IMPORTS
+
+#include "oaep.h"
+#include <functional>
+
+NAMESPACE_BEGIN(CryptoPP)
+
+// ********************************************************
+
+size_t OAEP_Base::MaxUnpaddedLength(size_t paddedLength) const
+{
+ return SaturatingSubtract(paddedLength/8, 1+2*DigestSize());
+}
+
+void OAEP_Base::Pad(RandomNumberGenerator &rng, const byte *input, size_t inputLength, byte *oaepBlock, size_t oaepBlockLen, const NameValuePairs ¶meters) const
+{
+ assert (inputLength <= MaxUnpaddedLength(oaepBlockLen));
+
+ // convert from bit length to byte length
+ if (oaepBlockLen % 8 != 0)
+ {
+ oaepBlock[0] = 0;
+ oaepBlock++;
+ }
+ oaepBlockLen /= 8;
+
+ std::auto_ptr<HashTransformation> pHash(NewHash());
+ const size_t hLen = pHash->DigestSize();
+ const size_t seedLen = hLen, dbLen = oaepBlockLen-seedLen;
+ byte *const maskedSeed = oaepBlock;
+ byte *const maskedDB = oaepBlock+seedLen;
+
+ ConstByteArrayParameter encodingParameters;
+ parameters.GetValue(Name::EncodingParameters(), encodingParameters);
+
+ // DB = pHash || 00 ... || 01 || M
+ pHash->CalculateDigest(maskedDB, encodingParameters.begin(), encodingParameters.size());
+ memset(maskedDB+hLen, 0, dbLen-hLen-inputLength-1);
+ maskedDB[dbLen-inputLength-1] = 0x01;
+ memcpy(maskedDB+dbLen-inputLength, input, inputLength);
+
+ rng.GenerateBlock(maskedSeed, seedLen);
+ std::auto_ptr<MaskGeneratingFunction> pMGF(NewMGF());
+ pMGF->GenerateAndMask(*pHash, maskedDB, dbLen, maskedSeed, seedLen);
+ pMGF->GenerateAndMask(*pHash, maskedSeed, seedLen, maskedDB, dbLen);
+}
+
+DecodingResult OAEP_Base::Unpad(const byte *oaepBlock, size_t oaepBlockLen, byte *output, const NameValuePairs ¶meters) const
+{
+ bool invalid = false;
+
+ // convert from bit length to byte length
+ if (oaepBlockLen % 8 != 0)
+ {
+ invalid = (oaepBlock[0] != 0) || invalid;
+ oaepBlock++;
+ }
+ oaepBlockLen /= 8;
+
+ std::auto_ptr<HashTransformation> pHash(NewHash());
+ const size_t hLen = pHash->DigestSize();
+ const size_t seedLen = hLen, dbLen = oaepBlockLen-seedLen;
+
+ invalid = (oaepBlockLen < 2*hLen+1) || invalid;
+
+ SecByteBlock t(oaepBlock, oaepBlockLen);
+ byte *const maskedSeed = t;
+ byte *const maskedDB = t+seedLen;
+
+ std::auto_ptr<MaskGeneratingFunction> pMGF(NewMGF());
+ pMGF->GenerateAndMask(*pHash, maskedSeed, seedLen, maskedDB, dbLen);
+ pMGF->GenerateAndMask(*pHash, maskedDB, dbLen, maskedSeed, seedLen);
+
+ ConstByteArrayParameter encodingParameters;
+ parameters.GetValue(Name::EncodingParameters(), encodingParameters);
+
+ // DB = pHash' || 00 ... || 01 || M
+ byte *M = std::find(maskedDB+hLen, maskedDB+dbLen, 0x01);
+ invalid = (M == maskedDB+dbLen) || invalid;
+ invalid = (std::find_if(maskedDB+hLen, M, std::bind2nd(std::not_equal_to<byte>(), 0)) != M) || invalid;
+ invalid = !pHash->VerifyDigest(maskedDB, encodingParameters.begin(), encodingParameters.size()) || invalid;
+
+ if (invalid)
+ return DecodingResult();
+
+ M++;
+ memcpy(output, M, maskedDB+dbLen-M);
+ return DecodingResult(maskedDB+dbLen-M);
+}
+
+NAMESPACE_END
+
+#endif
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