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lowentry.ue4.classes.internal.EncryptionRsa Maven / Gradle / Ivy
package lowentry.ue4.classes.internal;
import lowentry.ue4.classes.RsaKeys;
import lowentry.ue4.classes.RsaPrivateKey;
import lowentry.ue4.classes.RsaPublicKey;
import lowentry.ue4.classes.internal.rsa.RsaBigInteger;
public class EncryptionRsa
{
public static RsaKeys generateKeys(int bits)
{
for(int i = 1; i <= 100; i++)
{
RsaBigInteger p = RsaBigInteger.probablePrime(bits / 2);
if(p == null)
{
return null;
}
RsaBigInteger q = RsaBigInteger.probablePrime(bits / 2);
if(q == null)
{
return null;
}
RsaBigInteger n = p.multiply(q);
if(n == null)
{
return null;
}
RsaBigInteger pm1 = p.subtract(RsaBigInteger.ONE);
if(pm1 == null)
{
return null;
}
RsaBigInteger qm1 = q.subtract(RsaBigInteger.ONE);
if(qm1 == null)
{
return null;
}
RsaBigInteger m = pm1.multiply(qm1);
if(m == null)
{
return null;
}
RsaBigInteger e = RsaBigInteger.probablePrime(bits / 4);
if(e == null)
{
return null;
}
while(true)
{
RsaBigInteger mgcde = m.gcd(e);
if(mgcde == null)
{
return null;
}
if(mgcde.compareTo(RsaBigInteger.ONE) <= 0)
{
break;
}
if(e.compareTo(m) >= 0)
{
break;
}
e = e.add(RsaBigInteger.ONE);
if(e == null)
{
return null;
}
}
RsaBigInteger d = e.modInverse(m);
if(d == null)
{
return null;
}
if(d.equals(RsaBigInteger.ZERO))
{
continue;
}
RsaPublicKey publicKey = new RsaPublicKey(n, e);
RsaPrivateKey privateKey = new RsaPrivateKey(n, d, p, q);
if((privateKey.c2 == null) || privateKey.dp.equals(RsaBigInteger.ZERO) || privateKey.dq.equals(RsaBigInteger.ZERO))
{
continue;
}
return new RsaKeys(publicKey, privateKey);
}
return null;
}
public static byte[] encrypt(byte[] bytes, RsaPublicKey publicKey)
{
if((bytes == null) || (publicKey == null) || (publicKey.e == null) || (publicKey.n == null))
{
return new byte[0];
}
byte[] padded = PaddingOaep.pad(bytes, (int) Math.ceil(publicKey.n.bitLength() / 8.0));
RsaBigInteger integer = new RsaBigInteger(1, padded);
integer = integer.modPow(publicKey.e, publicKey.n);
if(integer == null)
{
return new byte[0];
}
return integer.toByteArray();
}
public static byte[] decrypt(byte[] bytes, RsaPrivateKey privateKey)
{
if((bytes == null) || (privateKey == null) || (privateKey.d == null) || (privateKey.n == null))
{
return new byte[0];
}
RsaBigInteger integer = new RsaBigInteger(1, bytes);
if((privateKey.c2 == null) || privateKey.dp.equals(RsaBigInteger.ZERO) || privateKey.dq.equals(RsaBigInteger.ZERO))
{
integer = integer.modPow(privateKey.d, privateKey.n);
if(integer == null)
{
return new byte[0];
}
}
else
{
RsaBigInteger cdp = integer.modPow(privateKey.dp, privateKey.p);
if(cdp == null)
{
return new byte[0];
}
RsaBigInteger cdq = integer.modPow(privateKey.dq, privateKey.q);
if(cdq == null)
{
return new byte[0];
}
RsaBigInteger u = cdq.subtract(cdp);
if(u == null)
{
return new byte[0];
}
u = u.multiply(privateKey.c2);
if(u == null)
{
return new byte[0];
}
u = u.remainder(privateKey.q);
if(u == null)
{
return new byte[0];
}
if(u.compareTo(RsaBigInteger.ZERO) < 0)
{
u = u.add(privateKey.q);
if(u == null)
{
return new byte[0];
}
}
integer = u.multiply(privateKey.p);
if(integer == null)
{
return new byte[0];
}
integer = cdp.add(integer);
if(integer == null)
{
return new byte[0];
}
}
byte[] padded = integer.toByteArray();
return PaddingOaep.unpad(padded);
}
public static byte[] publicKeyToBytes(RsaPublicKey publicKey)
{
if((publicKey == null) || (publicKey.e == null) || (publicKey.n == null))
{
return new byte[0];
}
byte[] n = publicKey.n.toByteArray();
byte[] e = publicKey.e.toByteArray();
return mergeBytes(uintegerToBytes(n.length), n, e);
}
public static RsaPublicKey bytesToPublicKey(byte[] bytes)
{
if(bytes == null)
{
return null;
}
int n = bytesToUinteger(bytes);
if(n <= 0)
{
return null;
}
int sn = ((n <= 127) ? 1 : 4);
int e = bytes.length - (sn + n);
return new RsaPublicKey(new RsaBigInteger(1, bytesSubArray(bytes, sn, n)), new RsaBigInteger(1, bytesSubArray(bytes, sn + n, e)));
}
public static RsaPublicKey bytesToPublicKey(byte[] bytes, int index, int length)
{
return bytesToPublicKey(bytesSubArray(bytes, index, length));
}
public static byte[] privateKeyToBytes(RsaPrivateKey privateKey)
{
if((privateKey == null) || (privateKey.d == null) || (privateKey.n == null) || (privateKey.p == null) || (privateKey.q == null))
{
return new byte[0];
}
byte[] n = privateKey.n.toByteArray();
byte[] d = privateKey.d.toByteArray();
byte[] p = privateKey.p.toByteArray();
byte[] q = privateKey.q.toByteArray();
return mergeBytes(uintegerToBytes(n.length), n, uintegerToBytes(d.length), d, uintegerToBytes(p.length), p, q);
}
public static RsaPrivateKey bytesToPrivateKey(byte[] bytes)
{
if(bytes == null)
{
return null;
}
int n = bytesToUinteger(bytes);
if(n <= 0)
{
return null;
}
int sn = ((n <= 127) ? 1 : 4);
int d = bytesToUinteger(bytes, sn + n);
if(d <= 0)
{
return null;
}
int sd = ((d <= 127) ? 1 : 4);
int p = bytesToUinteger(bytes, sn + n + sd + d);
if(p <= 0)
{
return null;
}
int sp = ((p <= 127) ? 1 : 4);
int q = bytes.length - (sn + n + sd + d + sp + p);
return new RsaPrivateKey(new RsaBigInteger(1, bytesSubArray(bytes, sn, n)), new RsaBigInteger(1, bytesSubArray(bytes, sn + n + sd, d)), new RsaBigInteger(1, bytesSubArray(bytes, sn + n + sd + d + sp, p)), new RsaBigInteger(1, bytesSubArray(bytes, sn + n + sd + d + sp + p, q)));
}
public static RsaPrivateKey bytesToPrivateKey(byte[] bytes, int index, int length)
{
return bytesToPrivateKey(bytesSubArray(bytes, index, length));
}
private static byte[] uintegerToBytes(int value)
{
if(value <= 127)
{
return new byte[]{(byte) value};
}
else
{
return new byte[]{(byte) ((value >> 24) | (1 << 7)), (byte) (value >> 16), (byte) (value >> 8), (byte) (value)};
}
}
private static int bytesToUinteger(byte[] bytes)
{
if(bytes.length <= 0)
{
return 0;
}
byte b = bytes[0];
if(((b >> 7) & 1) == 0)
{
return (b & 0xFF);
}
if(bytes.length <= 3)
{
return 0;
}
int value = (((b & 0xFF) & ~(1 << 7)) << 24) | ((bytes[1] & 0xFF) << 16) | ((bytes[2] & 0xFF) << 8) | (bytes[3] & 0xFF);
if(value <= 127)
{
return 0;
}
return value;
}
private static int bytesToUinteger(byte[] bytes, int offset)
{
if(bytes.length <= offset)
{
return 0;
}
byte b = bytes[offset];
if(((b >> 7) & 1) == 0)
{
return (b & 0xFF);
}
if(bytes.length <= (offset + 3))
{
return 0;
}
int value = (((b & 0xFF) & ~(1 << 7)) << 24) | ((bytes[offset + 1] & 0xFF) << 16) | ((bytes[offset + 2] & 0xFF) << 8) | (bytes[offset + 3] & 0xFF);
if(value <= 127)
{
return 0;
}
return value;
}
private static byte[] bytesSubArray(byte[] bytes, int index, int length)
{
if((bytes == null) || (bytes.length <= 0))
{
return new byte[0];
}
if(index < 0)
{
length += index;
index = 0;
}
if(length > (bytes.length - index))
{
length = bytes.length - index;
}
if(length <= 0)
{
return new byte[0];
}
if((index == 0) && (length == bytes.length))
{
return bytes;
}
byte[] c = new byte[length];
System.arraycopy(bytes, index, c, 0, c.length);
return c;
}
private static byte[] mergeBytes(byte[]... arrays)
{
if((arrays == null) || (arrays.length <= 0))
{
return new byte[0];
}
if(arrays.length == 1)
{
byte[] array = arrays[0];
if(array == null)
{
return new byte[0];
}
return array;
}
int length = 0;
for(byte[] array : arrays)
{
if(array != null)
{
length += array.length;
}
}
if(length <= 0)
{
return new byte[0];
}
byte[] merged = new byte[length];
int index = 0;
for(byte[] array : arrays)
{
if(array != null)
{
System.arraycopy(array, 0, merged, index, array.length);
index += array.length;
}
}
return merged;
}
}