AGentooCat/i2p.i2p
1
0
Fork 0
forked from I2P_Developers/i2p.i2p
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Crypto: New ChaCha20 wrapper around ChaChaCore, for use with Encrypted LS2

Browse Source
This commit is contained in:
zzz
2019-02-19 19:11:34 +00:00
parent 14ac8fe545
commit e34b646231
3 changed files with 182 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
core/java/src/com/southernstorm/noise/crypto/chacha20/ChaChaCore.java
View File

@@ -169,4 +169,45 @@ public final class ChaChaCore {
v[c] += v[d];
v[b] = leftRotate7(v[b] ^ v[c]);
}
/**
* XOR's the output of ChaCha20 with a byte buffer.
*
* @param input The input byte buffer.
* @param inputOffset The offset of the first input byte.
* @param output The output byte buffer (can be the same as the input).
* @param outputOffset The offset of the first output byte.
* @param length The number of bytes to XOR between 1 and 64.
* @param block The ChaCha20 output block.
*
* @since 0.9.39 moved from ChaChaPolyCipherState
*/
public static void xorBlock(byte[] input, int inputOffset, byte[] output, int outputOffset, int length, int[] block)
{
int posn = 0;
int value;
while (length >= 4) {
value = block[posn++];
output[outputOffset] = (byte)(input[inputOffset] ^ value);
output[outputOffset + 1] = (byte)(input[inputOffset + 1] ^ (value >> 8));
output[outputOffset + 2] = (byte)(input[inputOffset + 2] ^ (value >> 16));
output[outputOffset + 3] = (byte)(input[inputOffset + 3] ^ (value >> 24));
inputOffset += 4;
outputOffset += 4;
length -= 4;
}
if (length == 3) {
value = block[posn];
output[outputOffset] = (byte)(input[inputOffset] ^ value);
output[outputOffset + 1] = (byte)(input[inputOffset + 1] ^ (value >> 8));
output[outputOffset + 2] = (byte)(input[inputOffset + 2] ^ (value >> 16));
} else if (length == 2) {
value = block[posn];
output[outputOffset] = (byte)(input[inputOffset] ^ value);
output[outputOffset + 1] = (byte)(input[inputOffset + 1] ^ (value >> 8));
} else if (length == 1) {
value = block[posn];
output[outputOffset] = (byte)(input[inputOffset] ^ value);
}
}
}