void BigNum::fromBinary(const RawBuffer &buffer)
{
negative = false; // Can't init negatives yet
int alen = (buffer.length()*8 + BITS-1) / BITS;
grow(*this, alen, false);
len = alen;
int pos = 0;
n[pos] = 0;
int bitpos = 0;
// Index in reverse to get LSB first
for (int i = buffer.length()-1; i >= 0; --i)
{
word b = buffer[i] & 0xFF;
n[pos] |= (b << bitpos);
bitpos += 8;
if (bitpos >= BITS && i>0)
{
pos++;
n[pos] = 0;
bitpos -= BITS;
if (bitpos > 0)
n[pos] = b >> (8-bitpos);
}
}
void DmaBufferedUart::packDmaArgs(DmaChannel::StreamDefinition&def, RawBuffer&rb, int subset ){
def.device = &Uart::dcb->DR;
def.devicesize = 2; //uart allows for 9 bit words, like 8051 multidrop protocol or forced parity
def.buffer = rb.item(0);
def.numItems = subset > 0 ? subset : rb.length();
def.itemsize = rb.itemSize();
}
void AuthContext::AppendHashes(WriteBuffer &theBuf, const RawBuffer &theChallengeSeed)
{
AutoCrit aCrit(mDataCrit);
int aNumHashes = 0;
int aNumHashPos = theBuf.length();
theBuf.SkipBytes(1); // put num hashes here
AuthLoginCommunityMap::iterator anItr = mCommunityMap.begin();
while(anItr!=mCommunityMap.end())
{
AuthLoginCommunityData &aData = anItr->second;
if(!aData.mSimpleHash.empty())
{
MD5Digest aKeyedHash;
aKeyedHash.update(theChallengeSeed);
aKeyedHash.update(aData.mKeyedHashData);
RawBuffer aKeyedHashBuf = aKeyedHash.digest();
theBuf.AppendByte(1); // hash tag
theBuf.AppendWString(anItr->first); // community
theBuf.AppendBytes(aData.mSimpleHash.data(),aData.mSimpleHash.length());
theBuf.AppendBytes(aKeyedHashBuf.data(),aKeyedHashBuf.length());
aNumHashes++;
}
++anItr;
}
theBuf.SetByte(aNumHashPos,aNumHashes);
}
EGPublicKey::CryptReturn EGPublicKey::Encrypt(const void* theMsgP, unsigned long theLen) const
{
if ((! theMsgP) || (theLen == 0))
{
return CryptReturn(NULL,0);
}
RawBuffer anEncrypt;
if(!mElGamal.encrypt(theMsgP,theLen,anEncrypt))
return CryptReturn(NULL,0);
unsigned char *anOutP = new unsigned char[anEncrypt.length()];
memcpy(anOutP,anEncrypt.data(),anEncrypt.length());
return CryptReturn(anOutP,anEncrypt.length());
}
bool ElGamal::EncodeDigest(const RawBuffer& digest, BigInteger &h) const
{
IntegerExtractor aDecoder(digest.data(),digest.length(),false);
if(digest.length()*8 < q.bitLength())
{
if(!aDecoder.Decode(digest.length(),h))
return false;
}
else
{
if(!aDecoder.Decode(q.byteLength(),h))
return false;
h = h.shiftRight(q.byteLength()*8 - q.bitLength() + 1);
}
return true;
}
unsigned __int64 BigInteger::GetInt64() const
{
BigInteger r;
unsigned __int64 aVal = 0;
RawBuffer aBuf = toByteArray();
for(int i=0; i<aBuf.length(); i++)
{
aVal = (aVal<<8)|aBuf[i];
}
return aVal;
}
bool AuthContext::LoadVerifierKey(const std::string &theFile)
{
mCheckedVerifierFile = true;
FILE *aFile = fopen(theFile.c_str(),"rb");
if(aFile==NULL)
return false;
unsigned char aBuf[1024];
RawBuffer aKeyBuf;
while(!feof(aFile))
{
int aNumRead = fread(aBuf,1,1024,aFile);
if(aNumRead>0)
aKeyBuf.append(aBuf,aNumRead);
}
fclose(aFile);
AutoCrit aCrit(GetVerifierCrit());
return mVerifierKey.SetPublicKey(aKeyBuf.data(),aKeyBuf.length());
}
ByteBufferPtr ElGamal::Decrypt(const void *theCipherText, int theCipherTextLen) const
{
if(!IsPrivate())
return NULL;
const unsigned char *in = (const unsigned char*)theCipherText;
int inOffset = 0;
if(theCipherTextLen-inOffset<4) return NULL;
int aNumBlocks = LongFromLittleEndian(*(int*)in);
inOffset+=4;
if(theCipherTextLen-inOffset < aNumBlocks*modulusLen*2-inOffset)
return NULL;
RawBuffer aBuf(modulusLen,(unsigned char)0);
RawBuffer bBuf(modulusLen,(unsigned char)0);
WriteBuffer aDecrypt;
BigInteger a;;
BigInteger b;
BigInteger aPlainText;
for(int i=0; i<aNumBlocks; i++)
{
aBuf.assign(in+inOffset,modulusLen);
inOffset+=modulusLen;
bBuf.assign(in+inOffset,modulusLen);
inOffset+=modulusLen;
a.fromBinary(aBuf);
b.fromBinary(bBuf);
if(!decrypt(a,b,aPlainText))
return NULL;
RawBuffer aBigIntArray;
aPlainText.toBinary(aBigIntArray);
if(aBigIntArray.length()==0) return NULL;
int aPlainLen = aBigIntArray[aBigIntArray.length() - 1];
if(aPlainLen>modulusLen - 3)
return NULL;
if(aBigIntArray.length() - 1 - aPlainLen < 0)
{
int extra = aPlainLen - (aBigIntArray.length() - 1);
for(int j=0; j<extra; j++)
aDecrypt.AppendByte(0);
aDecrypt.AppendBytes(aBigIntArray.data(),aBigIntArray.length());
}
else
aDecrypt.AppendBytes(aBigIntArray.data()+aBigIntArray.length()-1-aPlainLen,aPlainLen);
}
return aDecrypt.ToByteBuffer();
}
