cNagra2 Class Reference

Inheritance diagram for cNagra2:

List of all members.

Protected Member Functions
virtual void	CreatePQ (const unsigned char *key, BIGNUM *p, BIGNUM *q)
bool	DecryptECM (const unsigned char *in, unsigned char *out, const unsigned char *key, int len, const unsigned char *vkey, BIGNUM *m)
bool	DecryptEMM (const unsigned char *in, unsigned char *out, const unsigned char *key, int len, const unsigned char *vkey, BIGNUM *m)
Protected Attributes
cIDEA	idea

---

Detailed Description

Definition at line 1135 of file nagra2.c.

---

Member Function Documentation

void cNagra2::CreatePQ	(	const unsigned char *	key,
		BIGNUM *	p,
		BIGNUM *	q
	)		[protected, virtual]

Implements cNagra.

Definition at line 1146 of file nagra2.c.

References cIDEA::Decrypt(), i, idea, cIDEA::SetEncKey(), and xxor.

{
  // Calculate P and Q from PK
  IdeaKS ks;
  idea.SetEncKey(key,&ks);
  // expand IDEA-G key
  unsigned char idata[96];
  for(int i=11; i>=0; i--) {
    unsigned char *d=&idata[i*8];
    memcpy(d,&key[13],8);
    *d^=i;
    idea.Decrypt(d,8,&ks,0);
    xxor(d,8,d,&key[13]);
    *d^=i;
    }
  // Calculate P
  idata[0] |= 0x80;
  idata[47] |= 1;
  BN_bin2bn(idata,48,p);
  BN_add_word(p,(key[21] << 5 ) | ((key[22] & 0xf0) >> 3));
  // Calculate Q
  idata[48] |= 0x80;
  idata[95] |= 1;
  BN_bin2bn(idata+48,48,q);
  BN_add_word(q,((key[22]&0xf)<<9) | (key[23]<<1));
}

bool cNagra2::DecryptECM	(	const unsigned char *	in,
		unsigned char *	out,
		const unsigned char *	key,
		int	len,
		const unsigned char *	vkey,
		BIGNUM *	m
	)		[protected]

Definition at line 1188 of file nagra2.c.

References cIDEA::Decrypt(), i, idea, L_SYS_CRYPTO, PRINTF, cNagra::pubExp, RotateBytes(), cRSA::RSA(), and cNagra::rsa.

Referenced by cSystemNagra2::ProcessECM().

{
  int sign=in[0] & 0x80;
  if(rsa.RSA(out,in+1,64,pubExp,m)<=0) {
    PRINTF(L_SYS_CRYPTO,"first RSA failed (ECM)");
    return false;
    }
  out[63]|=sign; // sign adjustment
  if(len>64) memcpy(out+64,in+65,len-64);

  if(in[0]&0x04) {
    unsigned char tmp[8];
    DES_key_schedule ks1, ks2; 
    RotateBytes(tmp,&key[0],8);
    DES_key_sched((DES_cblock *)tmp,&ks1);
    RotateBytes(tmp,&key[8],8);
    DES_key_sched((DES_cblock *)tmp,&ks2);
    memset(tmp,0,sizeof(tmp));
    for(int i=7; i>=0; i--) RotateBytes(out+8*i,8);
    DES_ede2_cbc_encrypt(out,out,len,&ks1,&ks2,(DES_cblock *)tmp,DES_DECRYPT);
    for(int i=7; i>=0; i--) RotateBytes(out+8*i,8);
    } 
  else idea.Decrypt(out,len,key,0); 

  RotateBytes(out,64);
  if(rsa.RSA(out,out,64,pubExp,m,false)<=0) {
    PRINTF(L_SYS_CRYPTO,"second RSA failed (ECM)");
    return false;
    }
  if(vkey && !Signature(vkey,out,out+8,len-8)) {
    PRINTF(L_SYS_CRYPTO,"signature failed (ECM)");
    return false;
    }
  return true;
}

bool cNagra2::DecryptEMM	(	const unsigned char *	in,
		unsigned char *	out,
		const unsigned char *	key,
		int	len,
		const unsigned char *	vkey,
		BIGNUM *	m
	)		[protected]

Definition at line 1224 of file nagra2.c.

References cNagra::CreateRSAPair(), cIDEA::Decrypt(), exp, idea, L_SYS_CRYPTO, PRINTF, cNagra::pubExp, RotateBytes(), cRSA::RSA(), and cNagra::rsa.

Referenced by cSystemNagra2::ProcessEMM().

{
  int sign=in[0]&0x80;
  if(rsa.RSA(out,in+1,96,pubExp,m)<=0) {
    PRINTF(L_SYS_CRYPTO,"first RSA failed (EMM)");
    return false;
    }
  out[95]|=sign; // sign adjustment
  cBN exp;
  if(in[0]&0x08) {
    // standard IDEA decrypt
    if(len>96) memcpy(out+96,in+97,len-96);
    idea.Decrypt(out,len,key,0);
    BN_set_word(exp,3);
    }
  else {
    // private RSA key expansion
    CreateRSAPair(key,0,exp,m);
    }
  RotateBytes(out,96);
  if(rsa.RSA(out,out,96,exp,m,false)<=0) {
    PRINTF(L_SYS_CRYPTO,"second RSA failed (EMM)");
    return false;
    }
  if(vkey && !Signature(vkey,out,out+8,len-8)) {
    PRINTF(L_SYS_CRYPTO,"signature failed (EMM)");
    return false;
    }
  return true;
}

---

Member Data Documentation

cIDEA cNagra2::idea [protected]

Definition at line 1139 of file nagra2.c.

Referenced by CreatePQ(), DecryptECM(), and DecryptEMM().

---

The documentation for this class was generated from the following file:

• sc/PLUGINS/src/sc-src/systems/nagra/nagra2.c