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-rw-r--r--src/cipher/cast/cast128.cpp170
1 files changed, 170 insertions, 0 deletions
diff --git a/src/cipher/cast/cast128.cpp b/src/cipher/cast/cast128.cpp
new file mode 100644
index 000000000..14e5c9e9d
--- /dev/null
+++ b/src/cipher/cast/cast128.cpp
@@ -0,0 +1,170 @@
+/*************************************************
+* CAST-128 Source File *
+* (C) 1999-2007 Jack Lloyd *
+*************************************************/
+
+#include <botan/cast128.h>
+#include <botan/loadstor.h>
+#include <botan/bit_ops.h>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* CAST-128 Round Type 1 *
+*************************************************/
+inline void R1(u32bit& L, u32bit R, u32bit MK, u32bit RK)
+ {
+ u32bit T = rotate_left(MK + R, RK);
+ L ^= (CAST_SBOX1[get_byte(0, T)] ^ CAST_SBOX2[get_byte(1, T)]) -
+ CAST_SBOX3[get_byte(2, T)] + CAST_SBOX4[get_byte(3, T)];
+ }
+
+/*************************************************
+* CAST-128 Round Type 2 *
+*************************************************/
+inline void R2(u32bit& L, u32bit R, u32bit MK, u32bit RK)
+ {
+ u32bit T = rotate_left(MK ^ R, RK);
+ L ^= (CAST_SBOX1[get_byte(0, T)] - CAST_SBOX2[get_byte(1, T)] +
+ CAST_SBOX3[get_byte(2, T)]) ^ CAST_SBOX4[get_byte(3, T)];
+ }
+
+/*************************************************
+* CAST-128 Round Type 3 *
+*************************************************/
+inline void R3(u32bit& L, u32bit R, u32bit MK, u32bit RK)
+ {
+ u32bit T = rotate_left(MK - R, RK);
+ L ^= ((CAST_SBOX1[get_byte(0, T)] + CAST_SBOX2[get_byte(1, T)]) ^
+ CAST_SBOX3[get_byte(2, T)]) - CAST_SBOX4[get_byte(3, T)];
+ }
+
+}
+
+/*************************************************
+* CAST-128 Encryption *
+*************************************************/
+void CAST_128::enc(const byte in[], byte out[]) const
+ {
+ u32bit L = load_be<u32bit>(in, 0);
+ u32bit R = load_be<u32bit>(in, 1);
+
+ R1(L, R, MK[ 0], RK[ 0]);
+ R2(R, L, MK[ 1], RK[ 1]);
+ R3(L, R, MK[ 2], RK[ 2]);
+ R1(R, L, MK[ 3], RK[ 3]);
+ R2(L, R, MK[ 4], RK[ 4]);
+ R3(R, L, MK[ 5], RK[ 5]);
+ R1(L, R, MK[ 6], RK[ 6]);
+ R2(R, L, MK[ 7], RK[ 7]);
+ R3(L, R, MK[ 8], RK[ 8]);
+ R1(R, L, MK[ 9], RK[ 9]);
+ R2(L, R, MK[10], RK[10]);
+ R3(R, L, MK[11], RK[11]);
+ R1(L, R, MK[12], RK[12]);
+ R2(R, L, MK[13], RK[13]);
+ R3(L, R, MK[14], RK[14]);
+ R1(R, L, MK[15], RK[15]);
+
+ store_be(out, R, L);
+ }
+
+/*************************************************
+* CAST-128 Decryption *
+*************************************************/
+void CAST_128::dec(const byte in[], byte out[]) const
+ {
+ u32bit L = load_be<u32bit>(in, 0);
+ u32bit R = load_be<u32bit>(in, 1);
+
+ R1(L, R, MK[15], RK[15]);
+ R3(R, L, MK[14], RK[14]);
+ R2(L, R, MK[13], RK[13]);
+ R1(R, L, MK[12], RK[12]);
+ R3(L, R, MK[11], RK[11]);
+ R2(R, L, MK[10], RK[10]);
+ R1(L, R, MK[ 9], RK[ 9]);
+ R3(R, L, MK[ 8], RK[ 8]);
+ R2(L, R, MK[ 7], RK[ 7]);
+ R1(R, L, MK[ 6], RK[ 6]);
+ R3(L, R, MK[ 5], RK[ 5]);
+ R2(R, L, MK[ 4], RK[ 4]);
+ R1(L, R, MK[ 3], RK[ 3]);
+ R3(R, L, MK[ 2], RK[ 2]);
+ R2(L, R, MK[ 1], RK[ 1]);
+ R1(R, L, MK[ 0], RK[ 0]);
+
+ store_be(out, R, L);
+ }
+
+/*************************************************
+* CAST-128 Key Schedule *
+*************************************************/
+void CAST_128::key(const byte key[], u32bit length)
+ {
+ clear();
+ SecureBuffer<u32bit, 4> X;
+ for(u32bit j = 0; j != length; ++j)
+ X[j/4] = (X[j/4] << 8) + key[j];
+
+ key_schedule(MK, X);
+ key_schedule(RK, X);
+
+ for(u32bit j = 0; j != 16; ++j)
+ RK[j] %= 32;
+ }
+
+/*************************************************
+* S-Box Based Key Expansion *
+*************************************************/
+void CAST_128::key_schedule(u32bit K[16], u32bit X[4])
+ {
+ class ByteReader
+ {
+ public:
+ byte operator()(u32bit i) { return (X[i/4] >> (8*(3 - (i%4)))); }
+ ByteReader(const u32bit* x) : X(x) {}
+ private:
+ const u32bit* X;
+ };
+
+ SecureBuffer<u32bit, 4> Z;
+ ByteReader x(X), z(Z);
+
+ Z[0] = X[0] ^ S5[x(13)] ^ S6[x(15)] ^ S7[x(12)] ^ S8[x(14)] ^ S7[x( 8)];
+ Z[1] = X[2] ^ S5[z( 0)] ^ S6[z( 2)] ^ S7[z( 1)] ^ S8[z( 3)] ^ S8[x(10)];
+ Z[2] = X[3] ^ S5[z( 7)] ^ S6[z( 6)] ^ S7[z( 5)] ^ S8[z( 4)] ^ S5[x( 9)];
+ Z[3] = X[1] ^ S5[z(10)] ^ S6[z( 9)] ^ S7[z(11)] ^ S8[z( 8)] ^ S6[x(11)];
+ K[ 0] = S5[z( 8)] ^ S6[z( 9)] ^ S7[z( 7)] ^ S8[z( 6)] ^ S5[z( 2)];
+ K[ 1] = S5[z(10)] ^ S6[z(11)] ^ S7[z( 5)] ^ S8[z( 4)] ^ S6[z( 6)];
+ K[ 2] = S5[z(12)] ^ S6[z(13)] ^ S7[z( 3)] ^ S8[z( 2)] ^ S7[z( 9)];
+ K[ 3] = S5[z(14)] ^ S6[z(15)] ^ S7[z( 1)] ^ S8[z( 0)] ^ S8[z(12)];
+ X[0] = Z[2] ^ S5[z( 5)] ^ S6[z( 7)] ^ S7[z( 4)] ^ S8[z( 6)] ^ S7[z( 0)];
+ X[1] = Z[0] ^ S5[x( 0)] ^ S6[x( 2)] ^ S7[x( 1)] ^ S8[x( 3)] ^ S8[z( 2)];
+ X[2] = Z[1] ^ S5[x( 7)] ^ S6[x( 6)] ^ S7[x( 5)] ^ S8[x( 4)] ^ S5[z( 1)];
+ X[3] = Z[3] ^ S5[x(10)] ^ S6[x( 9)] ^ S7[x(11)] ^ S8[x( 8)] ^ S6[z( 3)];
+ K[ 4] = S5[x( 3)] ^ S6[x( 2)] ^ S7[x(12)] ^ S8[x(13)] ^ S5[x( 8)];
+ K[ 5] = S5[x( 1)] ^ S6[x( 0)] ^ S7[x(14)] ^ S8[x(15)] ^ S6[x(13)];
+ K[ 6] = S5[x( 7)] ^ S6[x( 6)] ^ S7[x( 8)] ^ S8[x( 9)] ^ S7[x( 3)];
+ K[ 7] = S5[x( 5)] ^ S6[x( 4)] ^ S7[x(10)] ^ S8[x(11)] ^ S8[x( 7)];
+ Z[0] = X[0] ^ S5[x(13)] ^ S6[x(15)] ^ S7[x(12)] ^ S8[x(14)] ^ S7[x( 8)];
+ Z[1] = X[2] ^ S5[z( 0)] ^ S6[z( 2)] ^ S7[z( 1)] ^ S8[z( 3)] ^ S8[x(10)];
+ Z[2] = X[3] ^ S5[z( 7)] ^ S6[z( 6)] ^ S7[z( 5)] ^ S8[z( 4)] ^ S5[x( 9)];
+ Z[3] = X[1] ^ S5[z(10)] ^ S6[z( 9)] ^ S7[z(11)] ^ S8[z( 8)] ^ S6[x(11)];
+ K[ 8] = S5[z( 3)] ^ S6[z( 2)] ^ S7[z(12)] ^ S8[z(13)] ^ S5[z( 9)];
+ K[ 9] = S5[z( 1)] ^ S6[z( 0)] ^ S7[z(14)] ^ S8[z(15)] ^ S6[z(12)];
+ K[10] = S5[z( 7)] ^ S6[z( 6)] ^ S7[z( 8)] ^ S8[z( 9)] ^ S7[z( 2)];
+ K[11] = S5[z( 5)] ^ S6[z( 4)] ^ S7[z(10)] ^ S8[z(11)] ^ S8[z( 6)];
+ X[0] = Z[2] ^ S5[z( 5)] ^ S6[z( 7)] ^ S7[z( 4)] ^ S8[z( 6)] ^ S7[z( 0)];
+ X[1] = Z[0] ^ S5[x( 0)] ^ S6[x( 2)] ^ S7[x( 1)] ^ S8[x( 3)] ^ S8[z( 2)];
+ X[2] = Z[1] ^ S5[x( 7)] ^ S6[x( 6)] ^ S7[x( 5)] ^ S8[x( 4)] ^ S5[z( 1)];
+ X[3] = Z[3] ^ S5[x(10)] ^ S6[x( 9)] ^ S7[x(11)] ^ S8[x( 8)] ^ S6[z( 3)];
+ K[12] = S5[x( 8)] ^ S6[x( 9)] ^ S7[x( 7)] ^ S8[x( 6)] ^ S5[x( 3)];
+ K[13] = S5[x(10)] ^ S6[x(11)] ^ S7[x( 5)] ^ S8[x( 4)] ^ S6[x( 7)];
+ K[14] = S5[x(12)] ^ S6[x(13)] ^ S7[x( 3)] ^ S8[x( 2)] ^ S7[x( 8)];
+ K[15] = S5[x(14)] ^ S6[x(15)] ^ S7[x( 1)] ^ S8[x( 0)] ^ S8[x(13)];
+ }
+
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 19:59:09 +0000