bool cCamCryptNagra::MakeSessionKey(unsigned char *out, const unsigned char *camdata)
{
if(!hasMod) return false;
if(LOG(L_SC_PROC)) {
unsigned char bb[64];
camMod.Put(bb,sizeof(bb));
LDUMP(L_SC_PROC,bb,sizeof(bb),"Sessionkey negotiation CAMMOD:");
}
//decrypt $2A data here and prepare $2B reply
if(rsa.RSA(out,camdata,64,camExp,camMod)!=64) return false;
LDUMP(L_SC_PROC,out,64,"CMD 2A/26 after RSA:");
unsigned char key[16], sess[16];
InitKey(key,signature,cardid);
LDUMP(L_SC_PROC,key,16,"first IDEA key: ");
Signature(sess,key,out,32);
memcpy(key,sess,8);
memcpy(key+8,sess,8);
LDUMP(L_SC_PROC,key,16,"second IDEA key:");
Signature(sess+8,key,out,32);
LDUMP(L_SC_PROC,sess,16,"SESSION KEY: ");
idea.SetDecKey(sess,&sessKey);
if(rsa.RSA(out,out,64,camExp,camMod)!=64) return false;
LDUMP(L_SC_PROC,out,64,"CMD 2B/27 data:");
return true;
}
bool cCamCryptNagra::DecryptDT08(const unsigned char *dt08, unsigned int irdid, cBN *irdmod, bool fakeid)
{
if(LOG(L_SC_PROC)) {
unsigned char bb[64];
irdmod->Put(bb,sizeof(bb));
LDUMP(L_SC_PROC,bb,sizeof(bb),"DT08 decrypt IRDID: %08x IRDMOD:",irdid);
}
unsigned char buff[72];
if(rsa.RSA(buff,dt08+1,64,camExp,*irdmod)!=64) return false;
memcpy(buff+64,dt08+1+64,8);
buff[63]|=dt08[0]&0x80;
LDUMP(L_SC_PROC,buff,72,"DT08 after RSA");
unsigned char key[16];
InitKey(key,boxkey,irdid);
LDUMP(L_SC_PROC,key,16,"DT08 IDEA key");
IdeaKS dks;
idea.SetDecKey(key,&dks);
idea.Decrypt(buff,72,&dks,0);
LDUMP(L_SC_PROC,buff,72,"DT08 after IDEA");
memcpy(signature,buff,8);
LDUMP(L_SC_PROC,signature,8,"signature");
BYTE4_BE(buff ,0);
BYTE4_BE(buff+4,fakeid?0xFFFFFFFF:cardid);
Signature(buff,key,buff,72);
LDUMP(L_SC_PROC,buff,8,"check sig");
if(memcmp(signature,buff,8)) {
PRINTF(L_SC_PROC,"DT08 signature failed");
return false;
}
BN_bin2bn(buff+8,64,camMod);
hasMod=true;
return true;
}
bool cSystemConax::ProcessECM(const cEcmInfo *ecm, unsigned char *source)
{
int length=source[4]-2;
const int keyid=source[6];
const int nano=source[5];
source+=7;
cKeySnoop ks(this,'C',keyid,'M');
cPlainKey *pk;
cBN mod, exp;
if(!(pk=keys.FindKey('C',keyid,'E',-1))) {
if(doLog) PRINTF(L_SYS_KEY,"missing %02X E key",keyid);
return false;
}
pk->Get(exp);
if(!(pk=keys.FindKey('C',keyid,'M',-1))) {
if(doLog) PRINTF(L_SYS_KEY,"missing %02X M key",keyid);
return false;
}
pk->Get(mod);
for(int i=length ; i>0 ;) {
int index=i-64;
if(index<0) index=0;
if(rsa.RSA(source+index,source+index,64,exp,mod,false)<=0) {
if(doLog) PRINTF(L_SYS_CRYPTO,"RSA failed");
return false;
}
if(nano==0x63) {
// nano 0x63 block only decodes to 63 bytes
memmove(source+index,source+index+1,length-(index+1));
length-=1;
}
i-=(i%60 && index) ? i%60 : 64;
}
static const unsigned char hash[] = { 0x05,0x00,0x05 };
if(memcmp(hash,source+2,3) || memcmp(source+5,source+length-5,3)) {
if(doLog) PRINTF(L_SYS_ECM,"signature check failed");
return false;
}
ParseECM(source+10,length-10);
ks.OK(pk);
return true;
}
