Initial Vexta Core v0.1.0 release

src/crypto/chacha20.h

@@ -0,0 +1,35 @@
+// Copyright (c) 2017-2020 The Bitcoin Core developers
+// Copyright (c) 2017-2020 The DigiByte Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef DIGIBYTE_CRYPTO_CHACHA20_H
+#define DIGIBYTE_CRYPTO_CHACHA20_H
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/** A class for ChaCha20 256-bit stream cipher developed by Daniel J. Bernstein
+    https://cr.yp.to/chacha/chacha-20080128.pdf */
+class ChaCha20
+{
+private:
+    uint32_t input[16];
+
+public:
+    ChaCha20();
+    ChaCha20(const unsigned char* key, size_t keylen);
+    void SetKey(const unsigned char* key, size_t keylen); //!< set key with flexible keylength; 256bit recommended */
+    void SetIV(uint64_t iv); // set the 64bit nonce
+    void Seek(uint64_t pos); // set the 64bit block counter
+
+    /** outputs the keystream of size <bytes> into <c> */
+    void Keystream(unsigned char* c, size_t bytes);
+
+    /** enciphers the message <input> of length <bytes> and write the enciphered representation into <output>
+     *  Used for encryption and decryption (XOR)
+     */
+    void Crypt(const unsigned char* input, unsigned char* output, size_t bytes);
+};
+
+#endif // DIGIBYTE_CRYPTO_CHACHA20_H