1 files changed, 208 insertions, 0 deletions
diff --git a/modules/cipher/salsa20/salsa20.cpp b/modules/cipher/salsa20/salsa20.cpp
new file mode 100644
index 000000000..d11ba8799
--- /dev/null
+++ b/modules/cipher/salsa20/salsa20.cpp
@@ -0,0 +1,208 @@
+/*************************************************
+* Salsa20 Source File                            *
+* (C) 1999-2008 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/salsa20.h>
+#include <botan/mem_ops.h>
+#include <botan/xor_buf.h>
+#include <botan/loadstor.h>
+#include <botan/parsing.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Generate Salsa20 cipher stream                 *
+*************************************************/
+void salsa20(byte output[64], u32bit input[16])
+   {
+   u32bit x00 = input[0];
+   u32bit x01 = input[1];
+   u32bit x02 = input[2];
+   u32bit x03 = input[3];
+   u32bit x04 = input[4];
+   u32bit x05 = input[5];
+   u32bit x06 = input[6];
+   u32bit x07 = input[7];
+   u32bit x08 = input[8];
+   u32bit x09 = input[9];
+   u32bit x10 = input[10];
+   u32bit x11 = input[11];
+   u32bit x12 = input[12];
+   u32bit x13 = input[13];
+   u32bit x14 = input[14];
+   u32bit x15 = input[15];
+
+   for(u32bit i = 0; i != 10; ++i)
+      {
+      x04 ^= rotate_left(x00 + x12,  7);
+      x08 ^= rotate_left(x04 + x00,  9);
+      x12 ^= rotate_left(x08 + x04, 13);
+      x00 ^= rotate_left(x12 + x08, 18);
+      x09 ^= rotate_left(x05 + x01,  7);
+      x13 ^= rotate_left(x09 + x05,  9);
+      x01 ^= rotate_left(x13 + x09, 13);
+      x05 ^= rotate_left(x01 + x13, 18);
+      x14 ^= rotate_left(x10 + x06,  7);
+      x02 ^= rotate_left(x14 + x10,  9);
+      x06 ^= rotate_left(x02 + x14, 13);
+      x10 ^= rotate_left(x06 + x02, 18);
+      x03 ^= rotate_left(x15 + x11,  7);
+      x07 ^= rotate_left(x03 + x15,  9);
+      x11 ^= rotate_left(x07 + x03, 13);
+      x15 ^= rotate_left(x11 + x07, 18);
+
+      x01 ^= rotate_left(x00 + x03,  7);
+      x02 ^= rotate_left(x01 + x00,  9);
+      x03 ^= rotate_left(x02 + x01, 13);
+      x00 ^= rotate_left(x03 + x02, 18);
+      x06 ^= rotate_left(x05 + x04,  7);
+      x07 ^= rotate_left(x06 + x05,  9);
+      x04 ^= rotate_left(x07 + x06, 13);
+      x05 ^= rotate_left(x04 + x07, 18);
+      x11 ^= rotate_left(x10 + x09,  7);
+      x08 ^= rotate_left(x11 + x10,  9);
+      x09 ^= rotate_left(x08 + x11, 13);
+      x10 ^= rotate_left(x09 + x08, 18);
+      x12 ^= rotate_left(x15 + x14,  7);
+      x13 ^= rotate_left(x12 + x15,  9);
+      x14 ^= rotate_left(x13 + x12, 13);
+      x15 ^= rotate_left(x14 + x13, 18);
+      }
+
+   store_le(x00 + input[ 0], output + 4 *  0);
+   store_le(x01 + input[ 1], output + 4 *  1);
+   store_le(x02 + input[ 2], output + 4 *  2);
+   store_le(x03 + input[ 3], output + 4 *  3);
+   store_le(x04 + input[ 4], output + 4 *  4);
+   store_le(x05 + input[ 5], output + 4 *  5);
+   store_le(x06 + input[ 6], output + 4 *  6);
+   store_le(x07 + input[ 7], output + 4 *  7);
+   store_le(x08 + input[ 8], output + 4 *  8);
+   store_le(x09 + input[ 9], output + 4 *  9);
+   store_le(x10 + input[10], output + 4 * 10);
+   store_le(x11 + input[11], output + 4 * 11);
+   store_le(x12 + input[12], output + 4 * 12);
+   store_le(x13 + input[13], output + 4 * 13);
+   store_le(x14 + input[14], output + 4 * 14);
+   store_le(x15 + input[15], output + 4 * 15);
+
+   ++input[8];
+   if(!input[8])
+      ++input[9];
+   }
+
+}
+
+/*************************************************
+* Combine cipher stream with message             *
+*************************************************/
+void Salsa20::cipher(const byte in[], byte out[], u32bit length)
+   {
+   while(length >= buffer.size() - position)
+      {
+      xor_buf(out, in, buffer.begin() + position, buffer.size() - position);
+      length -= (buffer.size() - position);
+      in += (buffer.size() - position);
+      out += (buffer.size() - position);
+      salsa20(buffer.begin(), state);
+      position = 0;
+      }
+
+   xor_buf(out, in, buffer.begin() + position, length);
+
+   position += length;
+   }
+
+/*************************************************
+* Salsa20 Key Schedule                           *
+*************************************************/
+void Salsa20::key(const byte key[], u32bit length)
+   {
+   clear();
+
+   if(length == 16)
+      {
+      const u32bit TAU[] = { 0x61707865, 0x3120646e, 0x79622d36, 0x6b206574 };
+
+      state[0] = TAU[0];
+      state[1] = load_le<u32bit>(key, 0);
+      state[2] = load_le<u32bit>(key, 1);
+      state[3] = load_le<u32bit>(key, 2);
+      state[4] = load_le<u32bit>(key, 3);
+      state[5] = TAU[1];
+      state[10] = TAU[2];
+      state[11] = load_le<u32bit>(key, 0);
+      state[12] = load_le<u32bit>(key, 1);
+      state[13] = load_le<u32bit>(key, 2);
+      state[14] = load_le<u32bit>(key, 3);
+      state[15] = TAU[3];
+      }
+   else if(length == 32)
+      {
+      const u32bit SIGMA[] = { 0x61707865, 0x3320646e, 0x79622d32, 0x6b206574 };
+
+      state[0] = SIGMA[0];
+      state[1] = load_le<u32bit>(key, 0);
+      state[2] = load_le<u32bit>(key, 1);
+      state[3] = load_le<u32bit>(key, 2);
+      state[4] = load_le<u32bit>(key, 3);
+      state[5] = SIGMA[1];
+      state[10] = SIGMA[2];
+      state[11] = load_le<u32bit>(key, 4);
+      state[12] = load_le<u32bit>(key, 5);
+      state[13] = load_le<u32bit>(key, 6);
+      state[14] = load_le<u32bit>(key, 7);
+      state[15] = SIGMA[3];
+      }
+
+   const byte ZERO[8] = { 0 };
+   resync(ZERO, sizeof(ZERO));
+   }
+
+/*************************************************
+* Return the name of this type                   *
+*************************************************/
+void Salsa20::resync(const byte iv[], u32bit length)
+   {
+   if(length != IV_LENGTH)
+      throw Invalid_IV_Length(name(), length);
+
+   state[6] = load_le<u32bit>(iv, 0);
+   state[7] = load_le<u32bit>(iv, 1);
+   state[8] = 0;
+   state[9] = 0;
+
+   salsa20(buffer.begin(), state);
+   position = 0;
+   }
+
+/*************************************************
+* Return the name of this type                   *
+*************************************************/
+std::string Salsa20::name() const
+   {
+   return "Salsa20";
+   }
+
+/*************************************************
+* Clear memory of sensitive data                 *
+*************************************************/
+void Salsa20::clear() throw()
+   {
+   state.clear();
+   buffer.clear();
+   position = 0;
+   }
+
+/*************************************************
+* Salsa20 Constructor                            *
+*************************************************/
+Salsa20::Salsa20() : StreamCipher(16, 32, 16, 8)
+   {
+   clear();
+   }
+
+}