public BigInteger RSAVP1(Models.RSAPublicKey ne, BigInteger s)
{
if (s <= 0 || s >= ne.n - 1)
{
throw new Exception("signature representative out of range");
}
BigInteger m = BigInteger.ModPow(s, ne.e, ne.n);
return(m);
}
public BigInteger RSAEP(Models.RSAPublicKey ne, BigInteger m)
{
if (m <= 0 || m >= ne.n - 1)
{
throw new Exception("message representative out of range");
}
BigInteger c = BigInteger.ModPow(m, ne.e, ne.n);
return(c);
}
//*????????????????????SHA256 = 256 bits(32bytes)
public byte[] RSAES_OAEP_ENCRYPT(Models.RSAPublicKey ne, byte[] M, string L = "")
{
int mLen = (int)Math.Pow(2, 65) - 1;
int hLen = 256 / 8;
int k = ne.n.ToByteArray().Length;
if (L.Length > mLen)
{
throw new Exception("label too long");
}
if (mLen > k - 2 * hLen - 2)
{
throw new Exception("message too long");
}
// EME-OAEP encoding
SHA256Managed hashString = new SHA256Managed();
byte[] lHash = hashString.ComputeHash(Encoding.ASCII.GetBytes(L));
// DB = lHash || PS || 0x01 || M.
byte[] PS = new byte[k - mLen - 2 * hLen - 2];
byte[] DB = new byte[k - hLen - 1];
var list = new List <byte>();
list.AddRange(lHash);
list.AddRange(PS);
list.AddRange(new byte[] { 0x01 });
list.AddRange(M);
list.ToArray().CopyTo(DB, 0);
byte[] seed = new byte[hLen];
random.NextBytes(seed);
byte[] dbMask = MGF1(seed, k - hLen - 1);
byte[] maskedDB = new byte[k - hLen - 1];
for (int i = 0; i < k - hLen - 1; i++)
{
maskedDB[i] = (byte)(DB[i] ^ dbMask[i]);
}
byte[] seedMask = MGF1(maskedDB, hLen);
byte[] maskedSeed = new byte[hLen];
for (int i = 0; i < hLen; i++)
{
maskedSeed[i] = (byte)(seed[i] ^ seedMask[i]);
}
byte[] EM = new byte[k];
list = new List <byte>();
list.AddRange(new byte[] { 0x00 });
list.AddRange(maskedSeed);
list.AddRange(maskedDB);
list.ToArray().CopyTo(EM, 0);
// RSA encryption
BigInteger m = OS2IP(EM);
BigInteger c = RSAEP(ne, m);
byte[] C = I2OSP(c, k);
return(C);
}
public byte[] RSASSA_PKCS1_V1_5_VERIFY(Models.RSAPublicKey ne, byte[] M, byte[] S)
{
throw new NotImplementedException();
}
public string RSASSA_PSS_VERIFY(Models.RSAPublicKey ne, byte[] M, byte[] S)
{
throw new NotImplementedException();
}
public byte[] RSAES_PKCS1_V1_5_ENCRYPT(Models.RSAPublicKey ne, byte[] M)
{
throw new NotImplementedException();
}