1 files changed, 122 insertions, 0 deletions
diff --git a/botan/src/block/rc6/rc6.cpp b/botan/src/block/rc6/rc6.cpp
new file mode 100644
index 0000000..3b30ea9
--- /dev/null
+++ b/botan/src/block/rc6/rc6.cpp
@@ -0,0 +1,122 @@
+/*
+* 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::enc(const byte in[], byte out[]) const
+   {
+   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(u32bit 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);
+   }
+
+/*
+* RC6 Decryption
+*/
+void RC6::dec(const byte in[], byte out[]) const
+   {
+   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(u32bit 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);
+   }
+
+/*
+* RC6 Key Schedule
+*/
+void RC6::key_schedule(const byte key[], u32bit length)
+   {
+   const u32bit WORD_KEYLENGTH = (((length - 1) / 4) + 1),
+                MIX_ROUNDS     = 3*std::max(WORD_KEYLENGTH, S.size());
+   S[0] = 0xB7E15163;
+   for(u32bit j = 1; j != S.size(); ++j)
+      S[j] = S[j-1] + 0x9E3779B9;
+
+   SecureBuffer<u32bit, 8> K;
+   for(s32bit j = length-1; j >= 0; --j)
+      K[j/4] = (K[j/4] << 8) + key[j];
+   for(u32bit j = 0, A = 0, B = 0; j != MIX_ROUNDS; ++j)
+      {
+      A = rotate_left(S[j % S.size()] + A + B, 3);
+      B = rotate_left(K[j % WORD_KEYLENGTH] + A + B, (A + B) % 32);
+      S[j % S.size()] = A;
+      K[j % WORD_KEYLENGTH] = B;
+      }
+   }
+
+}