using System;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;
namespace Org.BouncyCastle.Crypto.Generators{
/**
* generate suitable parameters for GOST3410.
*/
public class Gost3410ParametersGenerator
{
private int size;
private int typeproc;
private SecureRandom init_random;
/**
* initialise the key generator.
*
* @param size size of the key
* @param typeProcedure type procedure A,B = 1; A',B' - else
* @param random random byte source.
*/
public void Init(
int size,
int typeProcedure,
SecureRandom random)
{
this.size = size;
this.typeproc = typeProcedure;
this.init_random = random;
}
//Procedure A
private int procedure_A(int x0, int c, BigInteger[] pq, int size)
{
//Verify and perform condition: 0<x<2^16; 0<c<2^16; c - odd.
while(x0<0 || x0>65536)
{
x0 = init_random.NextInt()/32768;
}
while((c<0 || c>65536) || (c/2==0))
{
c = init_random.NextInt()/32768 + 1;
}
BigInteger C = BigInteger.ValueOf(c);
BigInteger constA16 = BigInteger.ValueOf(19381);
//step1
BigInteger[] y = new BigInteger[1]; // begin length = 1
y[0] = BigInteger.ValueOf(x0);
//step 2
int[] t = new int[1]; // t - orders; begin length = 1
t[0] = size;
int s = 0;
for (int i=0; t[i]>=17; i++)
{
// extension array t
int[] tmp_t = new int[t.Length + 1]; ///////////////
Array.Copy(t,0,tmp_t,0,t.Length); // extension
t = new int[tmp_t.Length]; // array t
Array.Copy(tmp_t, 0, t, 0, tmp_t.Length); ///////////////
t[i+1] = t[i]/2;
s = i+1;
}
//step3
BigInteger[] p = new BigInteger[s+1];
p[s] = new BigInteger("8003",16); //set min prime number length 16 bit
int m = s-1; //step4
for (int i=0; i<s; i++)
{
int rm = t[m]/16; //step5
step6: for(;;)
{
//step 6
BigInteger[] tmp_y = new BigInteger[y.Length]; ////////////////
Array.Copy(y,0,tmp_y,0,y.Length); // extension
y = new BigInteger[rm+1]; // array y
Array.Copy(tmp_y,0,y,0,tmp_y.Length); ////////////////
for (int j=0; j<rm; j++)
{
y[j+1] = (y[j].Multiply(constA16).Add(C)).Mod(BigInteger.Two.Pow(16));
}
//step 7
BigInteger Ym = BigInteger.Zero;
for (int j=0; j<rm; j++)
{
Ym = Ym.Add(y[j].ShiftLeft(16*j));
}
y[0] = y[rm]; //step 8
//step 9
BigInteger N = BigInteger.One.ShiftLeft(t[m]-1).Divide(p[m+1]).Add(
Ym.ShiftLeft(t[m]-1).Divide(p[m+1].ShiftLeft(16*rm)));
if (N.TestBit(0))
{
N = N.Add(BigInteger.One);
}
//step 10
for(;;)
{
//step 11
BigInteger NByLastP = N.Multiply(p[m+1]);
if (NByLastP.BitLength > t[m])
{
goto step6; //step 12
}
p[m] = NByLastP.Add(BigInteger.One);
//step13
if (BigInteger.Two.ModPow(NByLastP, p[m]).CompareTo(BigInteger.One) == 0
&& BigInteger.Two.ModPow(N, p[m]).CompareTo(BigInteger.One) != 0)
{
break;
}
N = N.Add(BigInteger.Two);
}
if (--m < 0)
{
pq[0] = p[0];
pq[1] = p[1];
return y[0].IntValue; //return for procedure B step 2
}
break; //step 14
}
}
return y[0].IntValue;
}
//Procedure A'
private long procedure_Aa(long x0, long c, BigInteger[] pq, int size)
{
//Verify and perform condition: 0<x<2^32; 0<c<2^32; c - odd.
while(x0<0 || x0>4294967296L)
{
x0 = init_random.NextInt()*2;
}
while((c<0 || c>4294967296L) || (c/2==0))
{
c = init_random.NextInt()*2+1;
}
BigInteger C = BigInteger.ValueOf(c);
BigInteger constA32 = BigInteger.ValueOf(97781173);
//step1
BigInteger[] y = new BigInteger[1]; // begin length = 1
y[0] = BigInteger.ValueOf(x0);
//step 2
int[] t = new int[1]; // t - orders; begin length = 1
t[0] = size;
int s = 0;
for (int i=0; t[i]>=33; i++)
{
// extension array t
int[] tmp_t = new int[t.Length + 1]; ///////////////
Array.Copy(t,0,tmp_t,0,t.Length); // extension
t = new int[tmp_t.Length]; // array t
Array.Copy(tmp_t, 0, t, 0, tmp_t.Length); ///////////////
t[i+1] = t[i]/2;
s = i+1;
}
//step3
BigInteger[] p = new BigInteger[s+1];
p[s] = new BigInteger("8000000B",16); //set min prime number length 32 bit
int m = s-1; //step4
for (int i=0; i<s; i++)
{
int rm = t[m]/32; //step5
step6: for(;;)
{
//step 6
BigInteger[] tmp_y = new BigInteger[y.Length]; ////////////////
Array.Copy(y,0,tmp_y,0,y.Length); // extension
y = new BigInteger[rm+1]; // array y
Array.Copy(tmp_y,0,y,0,tmp_y.Length); ////////////////
for (int j=0; j<rm; j++)
{
y[j+1] = (y[j].Multiply(constA32).Add(C)).Mod(BigInteger.Two.Pow(32));
}
//step 7
BigInteger Ym = BigInteger.Zero;
for (int j=0; j<rm; j++)
{
Ym = Ym.Add(y[j].ShiftLeft(32*j));
}
y[0] = y[rm]; //step 8
//step 9
BigInteger N = BigInteger.One.ShiftLeft(t[m]-1).Divide(p[m+1]).Add(
Ym.ShiftLeft(t[m]-1).Divide(p[m+1].ShiftLeft(32*rm)));
if (N.TestBit(0))
{
N = N.Add(BigInteger.One);
}
//step 10
for(;;)
{
//step 11
BigInteger NByLastP = N.Multiply(p[m+1]);
if (NByLastP.BitLength > t[m])
{
goto step6; //step 12
}
p[m] = NByLastP.Add(BigInteger.One);
//step13
if (BigInteger.Two.ModPow(NByLastP, p[m]).CompareTo(BigInteger.One) == 0
&& BigInteger.Two.ModPow(N, p[m]).CompareTo(BigInteger.One) != 0)
{
break;
}
N = N.Add(BigInteger.Two);
}
if (--m < 0)
{
pq[0] = p[0];
pq[1] = p[1];
return y[0].LongValue; //return for procedure B' step 2
}
break; //step 14
}
}
return y[0].LongValue;
}
//Procedure B
private void procedure_B(int x0, int c, BigInteger[] pq)
{
//Verify and perform condition: 0<x<2^16; 0<c<2^16; c - odd.
while(x0<0 || x0>65536)
{
x0 = init_random.NextInt()/32768;
}
while((c<0 || c>65536) || (c/2==0))
{
c = init_random.NextInt()/32768 + 1;
}
BigInteger [] qp = new BigInteger[2];
BigInteger q = null, Q = null, p = null;
BigInteger C = BigInteger.ValueOf(c);
BigInteger constA16 = BigInteger.ValueOf(19381);
//step1
x0 = procedure_A(x0, c, qp, 256);
q = qp[0];
//step2
x0 = procedure_A(x0, c, qp, 512);
Q = qp[0];
BigInteger[] y = new BigInteger[65];
y[0] = BigInteger.ValueOf(x0);
const int tp = 1024;
BigInteger qQ = q.Multiply(Q);
step3:
for(;;)
{
//step 3
for (int j=0; j<64; j++)
{
y[j+1] = (y[j].Multiply(constA16).Add(C)).Mod(BigInteger.Two.Pow(16));
}
//step 4
BigInteger Y = BigInteger.Zero;
for (int j=0; j<64; j++)
{
Y = Y.Add(y[j].ShiftLeft(16*j));
}
y[0] = y[64]; //step 5
//step 6
BigInteger N = BigInteger.One.ShiftLeft(tp-1).Divide(qQ).Add(
Y.ShiftLeft(tp-1).Divide(qQ.ShiftLeft(1024)));
if (N.TestBit(0))
{
N = N.Add(BigInteger.One);
}
//step 7
for(;;)
{
//step 11
BigInteger qQN = qQ.Multiply(N);
if (qQN.BitLength > tp)
{
goto step3; //step 9
}
p = qQN.Add(BigInteger.One);
//step10
if (BigInteger.Two.ModPow(qQN, p).CompareTo(BigInteger.One) == 0
&& BigInteger.Two.ModPow(q.Multiply(N), p).CompareTo(BigInteger.One) != 0)
{
pq[0] = p;
pq[1] = q;
return;
}
N = N.Add(BigInteger.Two);
}
}
}
//Procedure B'
private void procedure_Bb(long x0, long c, BigInteger[] pq)
{
//Verify and perform condition: 0<x<2^32; 0<c<2^32; c - odd.
while(x0<0 || x0>4294967296L)
{
x0 = init_random.NextInt()*2;
}
while((c<0 || c>4294967296L) || (c/2==0))
{
c = init_random.NextInt()*2+1;
}
BigInteger [] qp = new BigInteger[2];
BigInteger q = null, Q = null, p = null;
BigInteger C = BigInteger.ValueOf(c);
BigInteger constA32 = BigInteger.ValueOf(97781173);
//step1
x0 = procedure_Aa(x0, c, qp, 256);
q = qp[0];
//step2
x0 = procedure_Aa(x0, c, qp, 512);
Q = qp[0];
BigInteger[] y = new BigInteger[33];
y[0] = BigInteger.ValueOf(x0);
const int tp = 1024;
BigInteger qQ = q.Multiply(Q);
step3:
for(;;)
{
//step 3
for (int j=0; j<32; j++)
{
y[j+1] = (y[j].Multiply(constA32).Add(C)).Mod(BigInteger.Two.Pow(32));
}
//step 4
BigInteger Y = BigInteger.Zero;
for (int j=0; j<32; j++)
{
Y = Y.Add(y[j].ShiftLeft(32*j));
}
y[0] = y[32]; //step 5
//step 6
BigInteger N = BigInteger.One.ShiftLeft(tp-1).Divide(qQ).Add(
Y.ShiftLeft(tp-1).Divide(qQ.ShiftLeft(1024)));
if (N.TestBit(0))
{
N = N.Add(BigInteger.One);
}
//step 7
for(;;)
{
//step 11
BigInteger qQN = qQ.Multiply(N);
if (qQN.BitLength > tp)
{
goto step3; //step 9
}
p = qQN.Add(BigInteger.One);
//step10
if (BigInteger.Two.ModPow(qQN, p).CompareTo(BigInteger.One) == 0
&& BigInteger.Two.ModPow(q.Multiply(N), p).CompareTo(BigInteger.One) != 0)
{
pq[0] = p;
pq[1] = q;
return;
}
N = N.Add(BigInteger.Two);
}
}
}
/**
* Procedure C
* procedure generates the a value from the given p,q,
* returning the a value.
*/
private BigInteger procedure_C(BigInteger p, BigInteger q)
{
BigInteger pSub1 = p.Subtract(BigInteger.One);
BigInteger pSub1Divq = pSub1.Divide(q);
for(;;)
{
BigInteger d = new BigInteger(p.BitLength, init_random);
// 1 < d < p-1
if (d.CompareTo(BigInteger.One) > 0 && d.CompareTo(pSub1) < 0)
{
BigInteger a = d.ModPow(pSub1Divq, p);
if (a.CompareTo(BigInteger.One) != 0)
{
return a;
}
}
}
}
/**
* which generates the p , q and a values from the given parameters,
* returning the Gost3410Parameters object.
*/
public Gost3410Parameters GenerateParameters()
{
BigInteger [] pq = new BigInteger[2];
BigInteger q = null, p = null, a = null;
int x0, c;
long x0L, cL;
if (typeproc==1)
{
x0 = init_random.NextInt();
c = init_random.NextInt();
switch(size)
{
case 512:
procedure_A(x0, c, pq, 512);
break;
case 1024:
procedure_B(x0, c, pq);
break;
default:
throw new ArgumentException("Ooops! key size 512 or 1024 bit.");
}
p = pq[0]; q = pq[1];
a = procedure_C(p, q);
//System.out.println("p:"+p.toString(16)+"\n"+"q:"+q.toString(16)+"\n"+"a:"+a.toString(16));
//System.out.println("p:"+p+"\n"+"q:"+q+"\n"+"a:"+a);
return new Gost3410Parameters(p, q, a, new Gost3410ValidationParameters(x0, c));
}
else
{
x0L = init_random.NextLong();
cL = init_random.NextLong();
switch(size)
{
case 512:
procedure_Aa(x0L, cL, pq, 512);
break;
case 1024:
procedure_Bb(x0L, cL, pq);
break;
default:
throw new InvalidOperationException("Ooops! key size 512 or 1024 bit.");
}
p = pq[0]; q = pq[1];
a = procedure_C(p, q);
//System.out.println("p:"+p.toString(16)+"\n"+"q:"+q.toString(16)+"\n"+"a:"+a.toString(16));
//System.out.println("p:"+p+"\n"+"q:"+q+"\n"+"a:"+a);
return new Gost3410Parameters(p, q, a, new Gost3410ValidationParameters(x0L, cL));
}
}
}
}
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