00001
00002
00003 #include "pch.h"
00004
00005 #include "pkcspad.h"
00006 #include <assert.h>
00007
00008 NAMESPACE_BEGIN(CryptoPP)
00009
00010
00011 template<> const byte PKCS_DigestDecoration<MD2>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,0x04,0x10};
00012 template<> const unsigned int PKCS_DigestDecoration<MD2>::length = sizeof(PKCS_DigestDecoration<MD2>::decoration);
00013
00014 template<> const byte PKCS_DigestDecoration<MD5>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,0x04,0x10};
00015 template<> const unsigned int PKCS_DigestDecoration<MD5>::length = sizeof(PKCS_DigestDecoration<MD5>::decoration);
00016
00017 template<> const byte PKCS_DigestDecoration<RIPEMD160>::decoration[] = {0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x24,0x03,0x02,0x01,0x05,0x00,0x04,0x14};
00018 template<> const unsigned int PKCS_DigestDecoration<RIPEMD160>::length = sizeof(PKCS_DigestDecoration<RIPEMD160>::decoration);
00019
00020 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};
00021 template<> const unsigned int PKCS_DigestDecoration<Tiger>::length = sizeof(PKCS_DigestDecoration<Tiger>::decoration);
00022
00023 size_t PKCS_EncryptionPaddingScheme::MaxUnpaddedLength(size_t paddedLength) const
00024 {
00025 return SaturatingSubtract(paddedLength/8, 10U);
00026 }
00027
00028 void PKCS_EncryptionPaddingScheme::Pad(RandomNumberGenerator &rng, const byte *input, size_t inputLen, byte *pkcsBlock, size_t pkcsBlockLen, const NameValuePairs ¶meters) const
00029 {
00030 assert (inputLen <= MaxUnpaddedLength(pkcsBlockLen));
00031
00032
00033 if (pkcsBlockLen % 8 != 0)
00034 {
00035 pkcsBlock[0] = 0;
00036 pkcsBlock++;
00037 }
00038 pkcsBlockLen /= 8;
00039
00040 pkcsBlock[0] = 2;
00041
00042
00043 for (unsigned i = 1; i < pkcsBlockLen-inputLen-1; i++)
00044 pkcsBlock[i] = (byte)rng.GenerateWord32(1, 0xff);
00045
00046 pkcsBlock[pkcsBlockLen-inputLen-1] = 0;
00047 memcpy(pkcsBlock+pkcsBlockLen-inputLen, input, inputLen);
00048 }
00049
00050 DecodingResult PKCS_EncryptionPaddingScheme::Unpad(const byte *pkcsBlock, size_t pkcsBlockLen, byte *output, const NameValuePairs ¶meters) const
00051 {
00052 bool invalid = false;
00053 size_t maxOutputLen = MaxUnpaddedLength(pkcsBlockLen);
00054
00055
00056 if (pkcsBlockLen % 8 != 0)
00057 {
00058 invalid = (pkcsBlock[0] != 0) || invalid;
00059 pkcsBlock++;
00060 }
00061 pkcsBlockLen /= 8;
00062
00063
00064 invalid = (pkcsBlock[0] != 2) || invalid;
00065
00066
00067 size_t i=1;
00068 while (i<pkcsBlockLen && pkcsBlock[i++]) {
00069 }
00070 assert(i==pkcsBlockLen || pkcsBlock[i-1]==0);
00071
00072 size_t outputLen = pkcsBlockLen - i;
00073 invalid = (outputLen > maxOutputLen) || invalid;
00074
00075 if (invalid)
00076 return DecodingResult();
00077
00078 memcpy (output, pkcsBlock+i, outputLen);
00079 return DecodingResult(outputLen);
00080 }
00081
00082
00083
00084 #ifndef CRYPTOPP_IMPORTS
00085
00086 void PKCS1v15_SignatureMessageEncodingMethod::ComputeMessageRepresentative(RandomNumberGenerator &rng,
00087 const byte *recoverableMessage, size_t recoverableMessageLength,
00088 HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
00089 byte *representative, size_t representativeBitLength) const
00090 {
00091 assert(representativeBitLength >= MinRepresentativeBitLength(hashIdentifier.second, hash.DigestSize()));
00092
00093 size_t pkcsBlockLen = representativeBitLength;
00094
00095 if (pkcsBlockLen % 8 != 0)
00096 {
00097 representative[0] = 0;
00098 representative++;
00099 }
00100 pkcsBlockLen /= 8;
00101
00102 representative[0] = 1;
00103
00104 unsigned int digestSize = hash.DigestSize();
00105 byte *pPadding = representative + 1;
00106 byte *pDigest = representative + pkcsBlockLen - digestSize;
00107 byte *pHashId = pDigest - hashIdentifier.second;
00108 byte *pSeparator = pHashId - 1;
00109
00110
00111 memset(pPadding, 0xff, pSeparator-pPadding);
00112 *pSeparator = 0;
00113 memcpy(pHashId, hashIdentifier.first, hashIdentifier.second);
00114 hash.Final(pDigest);
00115 }
00116
00117 #endif
00118
00119 NAMESPACE_END