1 files changed, 145 insertions, 0 deletions
diff --git a/src/lib/block/rc6/rc6.cpp b/src/lib/block/rc6/rc6.cpp
new file mode 100644
index 000000000..01255954d
--- /dev/null
+++ b/src/lib/block/rc6/rc6.cpp
@@ -0,0 +1,145 @@
+/*
+* RC6
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/rc6.h>
+#include <botan/loadstor.h>
+#include <botan/rotate.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*
+* RC6 Encryption
+*/
+void RC6::encrypt_n(const byte in[], byte out[], size_t blocks) const
+   {
+   for(size_t i = 0; i != blocks; ++i)
+      {
+      u32bit A = load_le<u32bit>(in, 0);
+      u32bit B = load_le<u32bit>(in, 1);
+      u32bit C = load_le<u32bit>(in, 2);
+      u32bit D = load_le<u32bit>(in, 3);
+
+      B += S[0]; D += S[1];
+
+      for(size_t j = 0; j != 20; j += 4)
+         {
+         u32bit T1, T2;
+
+         T1 = rotate_left(B*(2*B+1), 5);
+         T2 = rotate_left(D*(2*D+1), 5);
+         A = rotate_left(A ^ T1, T2 % 32) + S[2*j+2];
+         C = rotate_left(C ^ T2, T1 % 32) + S[2*j+3];
+
+         T1 = rotate_left(C*(2*C+1), 5);
+         T2 = rotate_left(A*(2*A+1), 5);
+         B = rotate_left(B ^ T1, T2 % 32) + S[2*j+4];
+         D = rotate_left(D ^ T2, T1 % 32) + S[2*j+5];
+
+         T1 = rotate_left(D*(2*D+1), 5);
+         T2 = rotate_left(B*(2*B+1), 5);
+         C = rotate_left(C ^ T1, T2 % 32) + S[2*j+6];
+         A = rotate_left(A ^ T2, T1 % 32) + S[2*j+7];
+
+         T1 = rotate_left(A*(2*A+1), 5);
+         T2 = rotate_left(C*(2*C+1), 5);
+         D = rotate_left(D ^ T1, T2 % 32) + S[2*j+8];
+         B = rotate_left(B ^ T2, T1 % 32) + S[2*j+9];
+         }
+
+      A += S[42]; C += S[43];
+
+      store_le(out, A, B, C, D);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
+   }
+
+/*
+* RC6 Decryption
+*/
+void RC6::decrypt_n(const byte in[], byte out[], size_t blocks) const
+   {
+   for(size_t i = 0; i != blocks; ++i)
+      {
+      u32bit A = load_le<u32bit>(in, 0);
+      u32bit B = load_le<u32bit>(in, 1);
+      u32bit C = load_le<u32bit>(in, 2);
+      u32bit D = load_le<u32bit>(in, 3);
+
+      C -= S[43]; A -= S[42];
+
+      for(size_t j = 0; j != 20; j += 4)
+         {
+         u32bit T1, T2;
+
+         T1 = rotate_left(A*(2*A+1), 5);
+         T2 = rotate_left(C*(2*C+1), 5);
+         B = rotate_right(B - S[41 - 2*j], T1 % 32) ^ T2;
+         D = rotate_right(D - S[40 - 2*j], T2 % 32) ^ T1;
+
+         T1 = rotate_left(D*(2*D+1), 5);
+         T2 = rotate_left(B*(2*B+1), 5);
+         A = rotate_right(A - S[39 - 2*j], T1 % 32) ^ T2;
+         C = rotate_right(C - S[38 - 2*j], T2 % 32) ^ T1;
+
+         T1 = rotate_left(C*(2*C+1), 5);
+         T2 = rotate_left(A*(2*A+1), 5);
+         D = rotate_right(D - S[37 - 2*j], T1 % 32) ^ T2;
+         B = rotate_right(B - S[36 - 2*j], T2 % 32) ^ T1;
+
+         T1 = rotate_left(B*(2*B+1), 5);
+         T2 = rotate_left(D*(2*D+1), 5);
+         C = rotate_right(C - S[35 - 2*j], T1 % 32) ^ T2;
+         A = rotate_right(A - S[34 - 2*j], T2 % 32) ^ T1;
+         }
+
+      D -= S[1]; B -= S[0];
+
+      store_le(out, A, B, C, D);
+
+      in += BLOCK_SIZE;
+      out += BLOCK_SIZE;
+      }
+   }
+
+/*
+* RC6 Key Schedule
+*/
+void RC6::key_schedule(const byte key[], size_t length)
+   {
+   S.resize(44);
+
+   const size_t WORD_KEYLENGTH = (((length - 1) / 4) + 1);
+   const size_t MIX_ROUNDS     = 3 * std::max(WORD_KEYLENGTH, S.size());
+
+   S[0] = 0xB7E15163;
+   for(size_t i = 1; i != S.size(); ++i)
+      S[i] = S[i-1] + 0x9E3779B9;
+
+   secure_vector<u32bit> K(8);
+
+   for(s32bit i = length-1; i >= 0; --i)
+      K[i/4] = (K[i/4] << 8) + key[i];
+
+   u32bit A = 0, B = 0;
+   for(size_t i = 0; i != MIX_ROUNDS; ++i)
+      {
+      A = rotate_left(S[i % S.size()] + A + B, 3);
+      B = rotate_left(K[i % WORD_KEYLENGTH] + A + B, (A + B) % 32);
+      S[i % S.size()] = A;
+      K[i % WORD_KEYLENGTH] = B;
+      }
+   }
+
+void RC6::clear()
+   {
+   zap(S);
+   }
+
+}