| public modInverse ( BigInteger modulus ) : BigInteger | ||
| modulus | BigInteger | |
| return | BigInteger | |
//проверка цифровой подписи.
public bool VerifDs(byte[] h, string sign, EcPoint q)
{
string rvector = sign.Substring(0, sign.Length / 2);
string svector = sign.Substring(sign.Length / 2, sign.Length / 2);
var r = new BigInteger(rvector, 16);
var s = new BigInteger(svector, 16);
if ((r < 1) || (r > (_n - 1)) || (s < 1) || (s > (_n - 1)))
{
return(false);
}
var a = new BigInteger(h);
BigInteger e = a % _n;
if (e == 0)
{
e = 1;
}
BigInteger v = e.modInverse(_n);
BigInteger z1 = (s * v) % _n;
BigInteger z2 = _n + ((-(r * v)) % _n);
_g = GDecompression();
EcPoint A = EcPoint.Multiply(_g, z1);
EcPoint b = EcPoint.Multiply(q, z2);
EcPoint c = A + b;
BigInteger R = c.X % _n;
return(R == r);
}
public static byte[] CreateSignature(byte[] p_data, ElGamalKeyStruct p_key_struct)
{
BigInteger x_pminusone = p_key_struct.P - 1;
// create K, which is the random number
BigInteger K;
do
{
K = new BigInteger();
K.genRandomBits(p_key_struct.P.bitCount() - 1, new Random());
} while (K.gcd(x_pminusone) != 1);
BigInteger A = p_key_struct.G.modPow(K, p_key_struct.P);
BigInteger B = mod(mod(K.modInverse(x_pminusone)
* (new BigInteger(p_data)
- (p_key_struct.X * (A))), (x_pminusone)), (x_pminusone));
byte[] x_a_bytes = A.getBytes();
byte[] x_b_bytes = B.getBytes();
// define the result size
int x_result_size = (((p_key_struct.P.bitCount() + 7) / 8) * 2);
// create an array to contain the ciphertext
byte[] x_result = new byte[x_result_size];
// populate the arrays
Array.Copy(x_a_bytes, 0, x_result, x_result_size / 2
- x_a_bytes.Length, x_a_bytes.Length);
Array.Copy(x_b_bytes, 0, x_result, x_result_size
- x_b_bytes.Length, x_b_bytes.Length);
// return the result array ..
return(x_result);
}
/**
* return true if the value r and s represent a DSA signature for
* the passed in message for standard DSA the message should be a
* SHA-1 hash of the real message to be verified.
*/
public bool verifySignature(
byte[] message,
BigInteger r,
BigInteger s)
{
BigInteger m = new BigInteger(1, message);
DSAParameters parameters = key.getParameters();
BigInteger zero = BigInteger.valueOf(0);
if (zero.compareTo(r) >= 0 || parameters.getQ().compareTo(r) <= 0)
{
return(false);
}
if (zero.compareTo(s) >= 0 || parameters.getQ().compareTo(s) <= 0)
{
return(false);
}
BigInteger w = s.modInverse(parameters.getQ());
BigInteger u1 = m.multiply(w).mod(parameters.getQ());
BigInteger u2 = r.multiply(w).mod(parameters.getQ());
u1 = parameters.getG().modPow(u1, parameters.getP());
u2 = ((DSAPublicKeyParameters)key).getY().modPow(u2, parameters.getP());
BigInteger v = u1.multiply(u2).mod(parameters.getP()).mod(parameters.getQ());
return(v.Equals(r));
}
protected internal bool VerifySignature(byte[] msg, BigInteger r, BigInteger s)
{
// Create a SHA1 hash of the message
SHA1Digest h = new SHA1Digest();
h.update(msg, 0, msg.Length);
byte[] data = new byte[h.getDigestSize()];
h.doFinal(data, 0);
BigInteger m = new BigInteger(1, data);
m = m.mod(q);
if (BigInteger.valueOf(0).compareTo(r) >= 0 || q.compareTo(r) <= 0)
{
return(false);
}
if (BigInteger.valueOf(0).compareTo(s) >= 0 || q.compareTo(s) <= 0)
{
return(false);
}
BigInteger w = s.modInverse(q);
BigInteger u1 = m.multiply(w).mod(q);
BigInteger u2 = r.multiply(w).mod(q);
BigInteger v = g.modPow(u1, p).multiply(y.modPow(u2, p)).mod(p).mod(q);
return(v.compareTo(r) == 0);
}
//сложение точки P c собой же
public static ECPoint Double(ECPoint p)
{
ECPoint p2 = new ECPoint();
p2.a = p.a;
p2.b = p.b;
p2.FieldChar = p.FieldChar;
BigInteger dy = 3 * p.x * p.x + p.a;
BigInteger dx = 2 * p.y;
if (dx < 0)
{
dx += p.FieldChar;
}
if (dy < 0)
{
dy += p.FieldChar;
}
BigInteger m = (dy * dx.modInverse(p.FieldChar)) % p.FieldChar;
p2.x = (m * m - p.x - p.x) % p.FieldChar;
p2.y = (m * (p.x - p2.x) - p.y) % p.FieldChar;
if (p2.x < 0)
{
p2.x += p.FieldChar;
}
if (p2.y < 0)
{
p2.y += p.FieldChar;
}
return(p2);
}
public static string GetPrivateKeyExponent(string p, string q)
{
BigInteger e = new BigInteger(Convert.ToInt64(17));
BigInteger d = e.modInverse((new BigInteger(p, _RADIX) - 1) * (new BigInteger(q, _RADIX) - 1));
return(d.ToString(_RADIX));
}
public static string GetPrivateKeyExponent(string p, string q)
{
BigInteger e = new BigInteger(Convert.ToInt64(17));
BigInteger d = e.modInverse((new BigInteger(p, _RADIX) - 1) * (new BigInteger(q, _RADIX) - 1));
return d.ToString(_RADIX);
}
//проверяем подпись
public bool SingVer(byte[] H, string sing, ECPoint Q)
{
string Rvector = sing.Substring(0, n.bitCount() / 4);
string Svector = sing.Substring(n.bitCount() / 4, n.bitCount() / 4);
BigInteger r = new BigInteger(Rvector, 16);
BigInteger s = new BigInteger(Svector, 16);
if ((r < 1) || (r > (n - 1)) || (s < 1) || (s > (n - 1)))
{
return(false);
}
BigInteger alpha = new BigInteger(H);
BigInteger e = alpha % n;
if (e == 0)
{
e = 1;
}
BigInteger v = e.modInverse(n);
BigInteger z1 = (s * v) % n;
BigInteger z2 = n + ((-(r * v)) % n);
ECPoint A = ECPoint.multiply(z1, G);
ECPoint B = ECPoint.multiply(z2, Q);
ECPoint C = A + B;
BigInteger R = C.x % n;
if (R == r)
{
return(true);
}
else
{
return(false);
}
}
/**
* generate a signature for the given message using the key we were
* initialised with. For conventional DSA the message should be a SHA-1
* hash of the message of interest.
*
* @param message the message that will be verified later.
*/
public BigInteger[] generateSignature(
byte[] message)
{
BigInteger m = new BigInteger(1, message);
DSAParameters parameters = key.getParameters();
BigInteger k;
do
{
k = new BigInteger(parameters.getQ().bitLength(), random);
}while (k.compareTo(parameters.getQ()) >= 0);
BigInteger r = parameters.getG().modPow(k, parameters.getP()).mod(parameters.getQ());
k = k.modInverse(parameters.getQ()).multiply(
m.add(((DSAPrivateKeyParameters)key).getX().multiply(r)));
BigInteger s = k.mod(parameters.getQ());
BigInteger[] res = new BigInteger[2];
res[0] = r;
res[1] = s;
return(res);
}
//функция вычисления квадратоного корня по модулю простого числа q
public BigInteger ModSqrt(BigInteger a, BigInteger q)
{
BigInteger b = new BigInteger();
do
{
b.genRandomBits(255, new Random());
} while (Legendre(b, q) == 1);
BigInteger s = 0;
BigInteger t = q - 1;
while ((t & 1) != 1)
{
s++;
t = t >> 1;
}
BigInteger InvA = a.modInverse(q);
BigInteger c = b.modPow(t, q);
BigInteger r = a.modPow(((t + 1) / 2), q);
BigInteger d = new BigInteger();
for (int i = 1; i < s; i++)
{
BigInteger temp = 2;
temp = temp.modPow((s - i - 1), q);
d = (r.modPow(2, q) * InvA).modPow(temp, q);
if (d == (q - 1))
r = (r * c) % q;
c = c.modPow(2, q);
}
return r;
}
//функция вычисления квадратоного корня по модулю простого числа q
public BigInteger ModSqrt(BigInteger a, BigInteger q)
{
BigInteger b = new BigInteger();
do
{
b.genRandomBits(255, new Random());
} while (Legendre(b, q) == 1);
BigInteger s = 0;
BigInteger t = q - 1;
while ((t & 1) != 1)
{
s++;
t = t >> 1;
}
BigInteger InvA = a.modInverse(q);
BigInteger c = b.modPow(t, q);
BigInteger r = a.modPow(((t + 1) / 2), q);
BigInteger d = new BigInteger();
for (int i = 1; i < s; i++)
{
BigInteger temp = 2;
temp = temp.modPow((s - i - 1), q);
d = (r.modPow(2, q) * InvA).modPow(temp, q);
if (d == (q - 1))
{
r = (r * c) % q;
}
c = c.modPow(2, q);
}
return(r);
}
public static byte[] CreateSignature(byte[] p_data, ElGamalKeyStruct p_key_struct)
{
BigInteger x_pminusone = p_key_struct.P - 1;
BigInteger K;
do
{
K = new BigInteger();
K.genRandomBits(p_key_struct.P.bitCount() - 1, new Random());
} while (K.gcd(x_pminusone) != 1);
BigInteger A = p_key_struct.G.modPow(K, p_key_struct.P);
BigInteger B = mod(mod(K.modInverse(x_pminusone) * (new BigInteger(p_data) - (p_key_struct.X * (A))), (x_pminusone)), (x_pminusone));
byte[] x_a_bytes = A.getBytes();
byte[] x_b_bytes = B.getBytes();
int x_result_size = (((p_key_struct.P.bitCount() + 7) / 8) * 2);
byte[] x_result = new byte[x_result_size];
Array.Copy(x_a_bytes, 0, x_result, x_result_size / 2 - x_a_bytes.Length, x_a_bytes.Length);
Array.Copy(x_b_bytes, 0, x_result, x_result_size - x_b_bytes.Length, x_b_bytes.Length);
return(x_result);
}
public void init(int keysize = 512)
{
Random rand = new Random();
m_e = m_pq.genCoPrime(keysize, rand);
m_d = m_e.modInverse(m_pq);
}
private BigInteger GenerateS(BigInteger r, byte[] data)
{
SHA1 sha1 = SHA1.Create();
BigInteger hash = new BigInteger(sha1.ComputeHash(data));
return(k.modInverse(q) * (hash + x * r) % q);
}
internal RSAKeyPair(BigInteger modulus, BigInteger e, BigInteger d, BigInteger p, BigInteger q)
{
_publickey = new RSAPublicKey(e, modulus);
_d = d;
_p = p;
_q = q;
_u = p.modInverse(q);
}
public long ReconstructData(SharedData[] shares)
{
BigInteger[] nominators = new BigInteger[numNecessaryParts];
for (int i = 0; i < numNecessaryParts; i++)
{
nominators[i] = 1;
for (int j = 0; j < numNecessaryParts; j++)
{
if (i != j)
{
BigInteger inv = new BigInteger(shares[i].xi) - new BigInteger(shares[j].xi);
inv = inv % modP;
if (inv < 0)
{
while (inv <= 0)
{
inv += modP;
}
inv = inv.modInverse(modP);
}
else if (inv != 1)
{
inv = inv.modInverse(modP);
}
nominators[i] = (nominators[i] * (new BigInteger(shares[j].xi) * inv)) % modP;
}
}
}
for (int i = 0; i < numNecessaryParts; i++)
{
nominators[i] = (nominators[i] * new BigInteger(shares[i].yi)) % modP;
}
BigInteger nominator = new BigInteger(0);
for (int i = 0; i < numNecessaryParts; i++)
{
nominator = (nominator + nominators[i]) % modP;
}
return(nominator.LongValue());
}
private BigInteger CalcolaD(BigInteger _e, BigInteger _b)
{
BigInteger _d = 0;
_d = _e.modInverse(_b);
return(_d);
}
internal RSAKeyPair(BigInteger modulus, BigInteger e, BigInteger d, BigInteger p, BigInteger q)
{
_publickey = new RSAPublicKey(e, modulus);
_d = d;
_p = p;
_q = q;
_u = p.modInverse(q);
}
public long ReconstructData(SharedData[] shares)
{
BigInteger[] nominators = new BigInteger[numNecessaryParts];
for (int i = 0; i < numNecessaryParts; i++)
{
nominators[i] = 1;
for (int j = 0; j < numNecessaryParts; j++)
{
if (i != j)
{
BigInteger inv = new BigInteger(shares[i].xi) - new BigInteger(shares[j].xi);
inv = inv % modP;
if (inv < 0)
{
while (inv <= 0)
inv += modP;
inv = inv.modInverse(modP);
}
else if (inv != 1)
{
inv = inv.modInverse(modP);
}
nominators[i] = (nominators[i] * (new BigInteger(shares[j].xi) * inv)) % modP;
}
}
}
for (int i = 0; i < numNecessaryParts; i++)
{
nominators[i] = (nominators[i] * new BigInteger(shares[i].yi)) % modP;
}
BigInteger nominator = new BigInteger(0);
for (int i = 0; i < numNecessaryParts; i++)
{
nominator = (nominator + nominators[i]) % modP;
}
return nominator.LongValue();
}
private BigInteger genrecshare(BigInteger Ri, BigInteger x)
{
BigInteger inverseX = x.modInverse(q);
BigInteger Si = new BigInteger(Ri.modPow(inverseX, p)); //to be reviewed
//Console.WriteLine("\nSi: " + Si);
return(Si);
}
private BigInteger GenerateD(BigInteger e, BigInteger totient)
{
BigInteger d = e.modInverse(totient);
if (d < 0)
{
d += totient;
}
return(d);
}
public void GeneratePair(int B, BigInteger _E)
{
E = _E;
int Qs = B >> 1;
while (true)
{
while (true)
{
P = BigInteger.genPseudoPrime(B - Qs, 1, new Random());
if ((P - 1).gcd(E) == 1 && P.isProbablePrime(10))
{
break;
}
}
while (true)
{
Q = BigInteger.genPseudoPrime(Qs, 1, new Random());
if ((Q - 1).gcd(E) == 1 && P.isProbablePrime(10))
{
break;
}
}
if (P < Q)
{
BigInteger t = P;
P = Q;
Q = t;
}
BigInteger phi = (P - 1) * (Q - 1);
if (phi.gcd(E) == 1)
{
N = P * Q;
D = E.modInverse(phi);
Dmp1 = D % (P - 1);
Dmq1 = D % (Q - 1);
Coeff = Q.modInverse(P);
break;
}
}
CanEncrypt = N != 0 && E != 0;
CanDecrypt = CanEncrypt && D != 0;
Console.WriteLine(N.ToString(16));
Console.WriteLine(D.ToString(16));
}
/**
* Performs modulo inverse
*
*/
private int modInverse(int num, int prime)
{
if (num == -1)
{
return(prime - 1);
}
BigInteger n = new BigInteger(num);
BigInteger p = new BigInteger(prime);
BigInteger result = n.modInverse(p);
return(result.IntValue());
}
public byte[] Sign(byte[] data)
{
BigInteger r = _publickey._g.modPow(_x, _publickey._p) % _publickey._q;
BigInteger s = (_x.modInverse(_publickey._q) * (new BigInteger(data) + _x * r)) % _publickey._q;
byte[] result = new byte[data.Length * 2];
byte[] br = r.getBytes();
byte[] bs = s.getBytes();
Array.Copy(br, 0, result, data.Length - br.Length, br.Length);
Array.Copy(bs, 0, result, data.Length * 2 - bs.Length, bs.Length);
return(result);
}
public static void GetE(string sp, string sdp)
{
sp = ConvertTool.RemoveSpace(sp);
sdp = ConvertTool.RemoveSpace(sdp);
BigInteger e, p, dp;
p = new BigInteger(sp, 16);
dp = new BigInteger(sdp, 16);
e = dp.modInverse(p - 1);
//e = temp % (p - 1);
RSA_E = e.ToHexString();
}
public void TestModInverse()
{
var a = new BigInteger("470782681346529800216759025446747092045188631141622615445464429840250748896490263346676188477401449398784352124574498378830506322639352584202116605974693692194824763263949618703029846313252400361025245824301828641617858127932941468016666971398736792667282916657805322080902778987073711188483372360907612588995664533157503380846449774089269965646418521613225981431666593065726252482995754339317299670566915780168", 10);
var b = a.modInverse(new BigInteger(1000000007));
Assert.AreEqual(736445995, b.LongValue());
b = a.modInverse(new BigInteger(1999));
Assert.AreEqual(1814, b.LongValue());
var isExceptionRaised = false;
try
{
b = a.modInverse(new BigInteger(9999998));
}
catch (ArithmeticException)
{
isExceptionRaised = true;
}
Assert.IsTrue(isExceptionRaised);
}
//проверяем подпись
// H - хэш-сумма
// sing - подпись
// Q - ключ проверки подписи
public bool SingVer(byte[] H, string sing, ECPoint Q)
{
// Шаг 1: вычисляем целые числа r и s по полученной подписи
string Rvector = sing.Substring(0, q.bitCount() / 4);
string Svector = sing.Substring(q.bitCount() / 4, q.bitCount() / 4);
BigInteger r = new BigInteger(Rvector, 16);
BigInteger s = new BigInteger(Svector, 16);
if ((r < 1) || (r > (q - 1)) || (s < 1) || (s > (q - 1)))
{
return(false);
}
// Шаг 3
BigInteger alpha = new BigInteger(H);
BigInteger e = alpha % q;
if (e == 0)
{
e = 1;
}
// Шаг 4
BigInteger v = e.modInverse(q);
// Шаг 5
BigInteger z1 = (s * v) % q;
BigInteger z2 = q + ((-(r * v)) % q);
// восст. y по x
this.Q = QDecompression();
// Шаг 6: найти C = z1 P + z2 Q
ECPoint A = ECPoint.multiply(z1, this.Q);
ECPoint B = ECPoint.multiply(z2, Q);
ECPoint C = A + B;
// R = xc (mod q)
BigInteger R = C.x % q;
//Шаг 7
if (R == r)
{
return(true);
}
else
{
return(false);
}
}
private void button1_Click(object sender, EventArgs e)
{
//Пример 2 из стандарта
BigInteger p = new BigInteger("3623986102229003635907788753683874306021320925534678605086546150450856166624002482588482022271496854025090823603058735163734263822371964987228582907372403", 10);
BigInteger x = new BigInteger("1928356944067022849399309401243137598997786635459507974357075491307766592685835441065557681003184874819658004903212332884252335830250729527632383493573274", 10);
BigInteger y = new BigInteger("2288728693371972859970012155529478416353562327329506180314497425931102860301572814141997072271708807066593850650334152381857347798885864807605098724013854", 10);
BigInteger a = new BigInteger(7);
BigInteger b = new BigInteger("1518655069210828534508950034714043154928747527740206436194018823352809982443793732829756914785974674866041605397883677596626326413990136959047435811826396", 10);
BigInteger k = new BigInteger("175516356025850499540628279921125280333451031747737791650208144243182057075034446102986750962508909227235866126872473516807810541747529710309879958632945", 10);
ECPoint P1 = new ECPoint();
P1.a = a;
P1.b = b;
P1.FieldChar = p;
P1.x = x;
P1.y = y;
ECPoint P3 = ECPoint.multiply(k, P1);
BigInteger r = P3.x % p;
/////// DS forming
BigInteger q = new BigInteger("3623986102229003635907788753683874306021320925534678605086546150450856166623969164898305032863068499961404079437936585455865192212970734808812618120619743", 10);
BigInteger d = new BigInteger("610081804136373098219538153239847583006845519069531562982388135354890606301782255383608393423372379057665527595116827307025046458837440766121180466875860", 10);
BigInteger E = new BigInteger("2897963881682868575562827278553865049173745197871825199562947419041388950970536661109553499954248733088719748844538964641281654463513296973827706272045964", 10);
BigInteger s = ((r * d) + (k * E)) % q;
//////// DS verification
BigInteger v = E.modInverse(q);
BigInteger z = (s * v) % q;
BigInteger z2 = q + ((-(r * v)) % q);
BigInteger x1 = new BigInteger("909546853002536596556690768669830310006929272546556281596372965370312498563182320436892870052842808608262832456858223580713780290717986855863433431150561", 10);
BigInteger y1 = new BigInteger(" 2921457203374425620632449734248415455640700823559488705164895837509539134297327397380287741428246088626609329139441895016863758984106326600572476822372076", 10);
ECPoint Q = new ECPoint();
Q.a = a;
Q.b = b;
Q.x = x1;
Q.y = y1;
Q.FieldChar = p;
ECPoint A = ECPoint.multiply(z, P1);
ECPoint B = ECPoint.multiply(z2, Q);
ECPoint C = A + B;
BigInteger R = C.x % q;
}
public void Verify(byte[] data, byte[] expecteddata)
{
byte[] first = new byte[data.Length / 2];
byte[] second = new byte[data.Length / 2];
Array.Copy(data, 0, first, 0, first.Length);
Array.Copy(data, first.Length, second, 0, second.Length);
BigInteger r = new BigInteger(first);
BigInteger s = new BigInteger(second);
BigInteger w = s.modInverse(_q);
BigInteger u1 = (new BigInteger(expecteddata) * w) % _q;
BigInteger u2 = (r * w) % _q;
BigInteger v = ((_g.modPow(u1, _p) * _y.modPow(u2, _p)) % _p) % _q;
if (v != r)
{
throw new VerifyException("Failed to verify");
}
}
//сложение пары точек.
public static EcPoint operator +(EcPoint p1, EcPoint p2)
{
var res = new EcPoint
{
A = p1.A,
B = p1.B,
FieldChar = p1.FieldChar
};
BigInteger dx = p2.X - p1.X;
BigInteger dy = p2.Y - p1.Y;
if (dx < 0)
{
dx += p1.FieldChar;
}
if (dy < 0)
{
dy += p1.FieldChar;
}
BigInteger t = (dy * dx.modInverse(p1.FieldChar)) % p1.FieldChar;
if (t < 0)
{
t += p1.FieldChar;
}
res.X = (t * t - p1.X - p2.X) % p1.FieldChar;
res.Y = (t * (p1.X - res.X) - p1.Y) % p1.FieldChar;
if (res.X < 0)
{
res.X += p1.FieldChar;
}
if (res.Y < 0)
{
res.Y += p1.FieldChar;
}
return(res);
}
public bool Verify(byte[] data, BigInteger r, BigInteger s)
{
if (r <= 0 || r >= q)
{
return(false);
}
if (s <= 0 || s >= q)
{
return(false);
}
SHA1 sha1 = SHA1.Create();
BigInteger hash = new BigInteger(sha1.ComputeHash(data));
BigInteger w = s.modInverse(q);
BigInteger u1 = (hash * w) % q;
BigInteger u2 = (r * w) % q;
BigInteger v = ((g.modPow(u1, p) * y.modPow(u2, p)) % p) % q;
return(v == r);
}
//сложение пары точек.
public static CECPoint operator +(CECPoint p1, CECPoint p2)
{
CECPoint res = new CECPoint();
res.a = p1.a;
res.b = p1.b;
res.fieldChar = p1.fieldChar;
BigInteger dx = p2.x - p1.x;
BigInteger dy = p2.y - p1.y;
if (dx < 0)
{
dx += p1.fieldChar;
}
if (dy < 0)
{
dy += p1.fieldChar;
}
BigInteger t = (dy * dx.modInverse(p1.fieldChar)) % p1.fieldChar;
if (t < 0)
{
t += p1.fieldChar;
}
res.x = (t * t - p1.x - p2.x) % p1.fieldChar;
res.y = (t * (p1.x - res.x) - p1.y) % p1.fieldChar;
if (res.x < 0)
{
res.x += p1.fieldChar;
}
if (res.y < 0)
{
res.y += p1.fieldChar;
}
return(res);
}
public rsa()
{
Random rn = new Random();
p = BigInteger.genPseudoPrime(520, 100, rn);
q = BigInteger.genPseudoPrime(520, 100, rn);
n = new BigInteger(p * q);
BigInteger o = new BigInteger((p - 1) * (q - 1));
int eb = 0;
do
{
//eb = rn.Next(2, o.bitCount());
//e = BigInteger.genPseudoPrime(eb, 100, rn);
e = new BigInteger(65537);
}while (e > o || e.gcd(o) != new BigInteger(1));
d = new BigInteger(e.modInverse(o));
}
public rsa()
{
Random rn = new Random();
p = BigInteger.genPseudoPrime(521, 100, rn);
q = BigInteger.genPseudoPrime(521, 100, rn);
n = new BigInteger(p * q);
BigInteger o = new BigInteger((p - 1) * (q - 1));
int eb=0;
do
{
//eb = rn.Next(2, o.bitCount());
//e = BigInteger.genPseudoPrime(eb, 100, rn);
e = new BigInteger(65537);
}
while (e > o || e.gcd(o) != new BigInteger(1));
d = new BigInteger(e.modInverse(o));
}
//проверка цифровой подписи.
public bool verifyDS(byte[] H, string sign, CECPoint Q)
{
string Rvector = sign.Substring(0, n.bitCount() / 4);
string Svector = sign.Substring(n.bitCount() / 4, n.bitCount() / 4);
BigInteger r = new BigInteger(Rvector, 16);
BigInteger s = new BigInteger(Svector, 16);
if ((r < 1) || (r > (n - 1)) || (s < 1) || (s > (n - 1)))
{
return(false);
}
BigInteger a = new BigInteger(H);
BigInteger e = a % n;
if (e == 0)
{
e = 1;
}
BigInteger v = e.modInverse(n);
BigInteger z1 = (s * v) % n;
BigInteger z2 = n + ((-(r * v)) % n);
this.G = gDecompression();
CECPoint A = CECPoint.multiply(G, z1);
CECPoint B = CECPoint.multiply(Q, z2);
CECPoint C = A + B;
BigInteger R = C.x % n;
if (R == r)
{
return(true);
}
else
{
return(false);
}
}
private BigInteger genrecshare(BigInteger Ri, BigInteger x)
{
BigInteger inverseX = x.modInverse(q);
BigInteger Si = new BigInteger(Ri.modPow(inverseX, p)); //to be reviewed
//Console.WriteLine("\nSi: " + Si);
return Si;
}
private static BigInteger modInverse(BigInteger a, BigInteger mod)
{
return a.modInverse(mod);
}
public void Verify(byte[] data, byte[] expecteddata)
{
byte[] first = new byte[data.Length/2];
byte[] second = new byte[data.Length/2];
Array.Copy(data, 0, first, 0, first.Length);
Array.Copy(data, first.Length, second, 0, second.Length);
BigInteger r = new BigInteger(first);
BigInteger s = new BigInteger(second);
BigInteger w = s.modInverse(_q);
BigInteger u1 = (new BigInteger(expecteddata) * w) % _q;
BigInteger u2 = (r * w) % _q;
BigInteger v = ((_g.modPow(u1, _p) * _y.modPow(u2, _p)) % _p) % _q;
//Debug.WriteLine(DebugUtil.DumpByteArray(v.GetBytes()));
//Debug.WriteLine(DebugUtil.DumpByteArray(r.GetBytes()));
if(v!=r) throw new VerifyException("Failed to verify");
}
