1 files changed, 133 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/stream/rc4/rc4.cpp b/comm/third_party/botan/src/lib/stream/rc4/rc4.cpp
new file mode 100644
index 0000000000..8bb01a2387
--- /dev/null
+++ b/comm/third_party/botan/src/lib/stream/rc4/rc4.cpp
@@ -0,0 +1,133 @@
+/*
+* RC4
+* (C) 1999-2007 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/rc4.h>
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+/*
+* Combine cipher stream with message
+*/
+void RC4::cipher(const uint8_t in[], uint8_t out[], size_t length)
+   {
+   verify_key_set(m_state.empty() == false);
+
+   while(length >= m_buffer.size() - m_position)
+      {
+      xor_buf(out, in, &m_buffer[m_position], m_buffer.size() - m_position);
+      length -= (m_buffer.size() - m_position);
+      in += (m_buffer.size() - m_position);
+      out += (m_buffer.size() - m_position);
+      generate();
+      }
+   xor_buf(out, in, &m_buffer[m_position], length);
+   m_position += length;
+   }
+
+StreamCipher* RC4::clone() const
+   {
+   return new RC4(m_SKIP);
+   }
+
+Key_Length_Specification RC4::key_spec() const
+   {
+   return Key_Length_Specification(1, 256);
+   }
+
+void RC4::set_iv(const uint8_t*, size_t length)
+   {
+   if(length > 0)
+      throw Invalid_IV_Length("RC4", length);
+   }
+
+/*
+* Generate cipher stream
+*/
+void RC4::generate()
+   {
+   uint8_t SX, SY;
+   for(size_t i = 0; i != m_buffer.size(); i += 4)
+      {
+      SX = m_state[m_X+1]; m_Y = (m_Y + SX) % 256; SY = m_state[m_Y];
+      m_state[m_X+1] = SY; m_state[m_Y] = SX;
+      m_buffer[i] = m_state[(SX + SY) % 256];
+
+      SX = m_state[m_X+2]; m_Y = (m_Y + SX) % 256; SY = m_state[m_Y];
+      m_state[m_X+2] = SY; m_state[m_Y] = SX;
+      m_buffer[i+1] = m_state[(SX + SY) % 256];
+
+      SX = m_state[m_X+3]; m_Y = (m_Y + SX) % 256; SY = m_state[m_Y];
+      m_state[m_X+3] = SY; m_state[m_Y] = SX;
+      m_buffer[i+2] = m_state[(SX + SY) % 256];
+
+      m_X = (m_X + 4) % 256;
+      SX = m_state[m_X]; m_Y = (m_Y + SX) % 256; SY = m_state[m_Y];
+      m_state[m_X] = SY; m_state[m_Y] = SX;
+      m_buffer[i+3] = m_state[(SX + SY) % 256];
+      }
+   m_position = 0;
+   }
+
+/*
+* RC4 Key Schedule
+*/
+void RC4::key_schedule(const uint8_t key[], size_t length)
+   {
+   m_state.resize(256);
+   m_buffer.resize(256);
+
+   m_position = m_X = m_Y = 0;
+
+   for(size_t i = 0; i != 256; ++i)
+      m_state[i] = static_cast<uint8_t>(i);
+
+   for(size_t i = 0, state_index = 0; i != 256; ++i)
+      {
+      state_index = (state_index + key[i % length] + m_state[i]) % 256;
+      std::swap(m_state[i], m_state[state_index]);
+      }
+
+   for(size_t i = 0; i <= m_SKIP; i += m_buffer.size())
+      generate();
+
+   m_position += (m_SKIP % m_buffer.size());
+   }
+
+/*
+* Return the name of this type
+*/
+std::string RC4::name() const
+   {
+   if(m_SKIP == 0)
+      return "RC4";
+   else if(m_SKIP == 256)
+      return "MARK-4";
+   else
+      return "RC4(" + std::to_string(m_SKIP) + ")";
+   }
+
+/*
+* Clear memory of sensitive data
+*/
+void RC4::clear()
+   {
+   zap(m_state);
+   zap(m_buffer);
+   m_position = m_X = m_Y = 0;
+   }
+
+/*
+* RC4 Constructor
+*/
+RC4::RC4(size_t s) : m_SKIP(s) {}
+
+void RC4::seek(uint64_t)
+   {
+   throw Not_Implemented("RC4 does not support seeking");
+   }
+}