nfqws2: add mtproto detection

nfq2/crypto/aes-ctr.c

@@ -0,0 +1,38 @@
+#include "aes-ctr.h"
+#include <string.h>
+
+#define AES_BLOCKLEN 16
+
+void aes_ctr_xcrypt_buffer(aes_context *ctx, const uint8_t *iv, uint8_t *buf, size_t length)
+{
+	uint8_t bi, buffer[AES_BLOCKLEN], ivc[AES_BLOCKLEN];
+	size_t i;
+
+	memcpy(ivc,iv,AES_BLOCKLEN);
+
+	for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi)
+	{
+		if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */
+		{
+			memcpy(buffer, ivc, AES_BLOCKLEN);
+			aes_cipher(ctx, buffer, buffer);
+
+			/* Increment ivc and handle overflow */
+			for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
+			{
+				/* inc will owerflow */
+				if (ivc[bi] == 255)
+				{
+					ivc[bi] = 0;
+					continue;
+				}
+				ivc[bi] += 1;
+				break;
+			}
+			bi = 0;
+		}
+		buf[i] = (buf[i] ^ buffer[bi]);
+	}
+}
+
+

nfq2/crypto/aes-ctr.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdint.h>
+#include "aes.h"
+
+// this function rewrites buf
+void aes_ctr_xcrypt_buffer(aes_context *ctx, const uint8_t *iv, uint8_t *buf, size_t length);