1 files changed, 82 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/stream/chacha/chacha.h b/comm/third_party/botan/src/lib/stream/chacha/chacha.h
new file mode 100644
index 0000000000..1749127f28
--- /dev/null
+++ b/comm/third_party/botan/src/lib/stream/chacha/chacha.h
@@ -0,0 +1,82 @@
+/*
+* ChaCha20
+* (C) 2014,2018 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_CHACHA_H_
+#define BOTAN_CHACHA_H_
+
+#include <botan/stream_cipher.h>
+
+BOTAN_FUTURE_INTERNAL_HEADER(chacha.h)
+
+namespace Botan {
+
+/**
+* DJB's ChaCha (https://cr.yp.to/chacha.html)
+*/
+class BOTAN_PUBLIC_API(2,0) ChaCha final : public StreamCipher
+   {
+   public:
+      /**
+      * @param rounds number of rounds
+      * @note Currently only 8, 12 or 20 rounds are supported, all others
+      * will throw an exception
+      */
+      explicit ChaCha(size_t rounds = 20);
+
+      std::string provider() const override;
+
+      void cipher(const uint8_t in[], uint8_t out[], size_t length) override;
+
+      void write_keystream(uint8_t out[], size_t len) override;
+
+      void set_iv(const uint8_t iv[], size_t iv_len) override;
+
+      /*
+      * ChaCha accepts 0, 8, 12 or 24 byte IVs.
+      * The default IV is a 8 zero bytes.
+      * An IV of length 0 is treated the same as the default zero IV.
+      * An IV of length 24 selects XChaCha mode
+      */
+      bool valid_iv_length(size_t iv_len) const override;
+
+      size_t default_iv_length() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      void clear() override;
+
+      StreamCipher* clone() const override;
+
+      std::string name() const override;
+
+      void seek(uint64_t offset) override;
+
+   private:
+      void key_schedule(const uint8_t key[], size_t key_len) override;
+
+      void initialize_state();
+
+      void chacha_x8(uint8_t output[64*8], uint32_t state[16], size_t rounds);
+
+#if defined(BOTAN_HAS_CHACHA_SIMD32)
+      void chacha_simd32_x4(uint8_t output[64*4], uint32_t state[16], size_t rounds);
+#endif
+
+#if defined(BOTAN_HAS_CHACHA_AVX2)
+      void chacha_avx2_x8(uint8_t output[64*8], uint32_t state[16], size_t rounds);
+#endif
+
+      size_t m_rounds;
+      secure_vector<uint32_t> m_key;
+      secure_vector<uint32_t> m_state;
+      secure_vector<uint8_t> m_buffer;
+      size_t m_position = 0;
+   };
+
+}
+
+#endif