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authorlloyd <[email protected]>2008-11-08 19:46:52 +0000
committerlloyd <[email protected]>2008-11-08 19:46:52 +0000
commitf1c459725da56fd8ed5766e7779300182fa26bcf (patch)
tree32295cec92df1155563ae8a535dc695d6800d7f6 /src/block/rc5/rc5.cpp
parent8dba7b5264403e781bbb86ff61850e4377dca7b9 (diff)
Split ciphers into block and stream ciphers. Move base class headers
Diffstat (limited to 'src/block/rc5/rc5.cpp')
-rw-r--r--src/block/rc5/rc5.cpp101
1 files changed, 101 insertions, 0 deletions
diff --git a/src/block/rc5/rc5.cpp b/src/block/rc5/rc5.cpp
new file mode 100644
index 000000000..0c0229b6c
--- /dev/null
+++ b/src/block/rc5/rc5.cpp
@@ -0,0 +1,101 @@
+/*************************************************
+* RC5 Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#include <botan/rc5.h>
+#include <botan/loadstor.h>
+#include <botan/bit_ops.h>
+#include <botan/parsing.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*************************************************
+* RC5 Encryption *
+*************************************************/
+void RC5::enc(const byte in[], byte out[]) const
+ {
+ u32bit A = load_le<u32bit>(in, 0), B = load_le<u32bit>(in, 1);
+
+ A += S[0]; B += S[1];
+ for(u32bit j = 0; j != ROUNDS; j += 4)
+ {
+ A = rotate_left(A ^ B, B % 32) + S[2*j+2];
+ B = rotate_left(B ^ A, A % 32) + S[2*j+3];
+ A = rotate_left(A ^ B, B % 32) + S[2*j+4];
+ B = rotate_left(B ^ A, A % 32) + S[2*j+5];
+ A = rotate_left(A ^ B, B % 32) + S[2*j+6];
+ B = rotate_left(B ^ A, A % 32) + S[2*j+7];
+ A = rotate_left(A ^ B, B % 32) + S[2*j+8];
+ B = rotate_left(B ^ A, A % 32) + S[2*j+9];
+ }
+
+ store_le(out, A, B);
+ }
+
+/*************************************************
+* RC5 Decryption *
+*************************************************/
+void RC5::dec(const byte in[], byte out[]) const
+ {
+ u32bit A = load_le<u32bit>(in, 0), B = load_le<u32bit>(in, 1);
+
+ for(u32bit j = ROUNDS; j != 0; j -= 4)
+ {
+ B = rotate_right(B - S[2*j+1], A % 32) ^ A;
+ A = rotate_right(A - S[2*j ], B % 32) ^ B;
+ B = rotate_right(B - S[2*j-1], A % 32) ^ A;
+ A = rotate_right(A - S[2*j-2], B % 32) ^ B;
+ B = rotate_right(B - S[2*j-3], A % 32) ^ A;
+ A = rotate_right(A - S[2*j-4], B % 32) ^ B;
+ B = rotate_right(B - S[2*j-5], A % 32) ^ A;
+ A = rotate_right(A - S[2*j-6], B % 32) ^ B;
+ }
+ B -= S[1]; A -= S[0];
+
+ store_le(out, A, B);
+ }
+
+/*************************************************
+* RC5 Key Schedule *
+*************************************************/
+void RC5::key(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;
+ }
+ }
+
+/*************************************************
+* Return the name of this type *
+*************************************************/
+std::string RC5::name() const
+ {
+ return "RC5(" + to_string(ROUNDS) + ")";
+ }
+
+/*************************************************
+* RC5 Constructor *
+*************************************************/
+RC5::RC5(u32bit r) : BlockCipher(8, 1, 32), ROUNDS(r)
+ {
+ if(ROUNDS < 8 || ROUNDS > 32 || (ROUNDS % 4 != 0))
+ throw Invalid_Argument(name() + ": Invalid number of rounds");
+ S.create(2*ROUNDS + 2);
+ }
+
+}