1 files changed, 80 insertions, 0 deletions
diff --git a/src/gost.cpp b/src/gost.cpp
new file mode 100644
index 000000000..6e6026580
--- /dev/null
+++ b/src/gost.cpp
@@ -0,0 +1,80 @@
+/*************************************************
+* GOST Source File                               *
+* (C) 1999-2006 The Botan Project                *
+*************************************************/
+
+#include <botan/gost.h>
+#include <botan/bit_ops.h>
+
+namespace Botan {
+
+/*************************************************
+* GOST Encryption                                *
+*************************************************/
+void GOST::enc(const byte in[], byte out[]) const
+   {
+   u32bit N1 = make_u32bit(in[3], in[2], in[1], in[0]),
+          N2 = make_u32bit(in[7], in[6], in[5], in[4]);
+
+   for(u32bit j = 0; j != 32; j += 2)
+      {
+      u32bit T0;
+
+      T0 = N1 + EK[j];
+      N2 ^= SBOX1[get_byte(0, T0)] | SBOX2[get_byte(1, T0)] |
+            SBOX3[get_byte(2, T0)] | SBOX4[get_byte(3, T0)];
+
+      T0 = N2 + EK[j+1];
+      N1 ^= SBOX1[get_byte(0, T0)] | SBOX2[get_byte(1, T0)] |
+            SBOX3[get_byte(2, T0)] | SBOX4[get_byte(3, T0)];
+      }
+
+   out[0] = get_byte(3, N2); out[1] = get_byte(2, N2);
+   out[2] = get_byte(1, N2); out[3] = get_byte(0, N2);
+   out[4] = get_byte(3, N1); out[5] = get_byte(2, N1);
+   out[6] = get_byte(1, N1); out[7] = get_byte(0, N1);
+   }
+
+/*************************************************
+* GOST Decryption                                *
+*************************************************/
+void GOST::dec(const byte in[], byte out[]) const
+   {
+   u32bit N1 = make_u32bit(in[3], in[2], in[1], in[0]),
+          N2 = make_u32bit(in[7], in[6], in[5], in[4]);
+
+   for(u32bit j = 0; j != 32; j += 2)
+      {
+      u32bit T0;
+
+      T0 = N1 + EK[31-j];
+      N2 ^= SBOX1[get_byte(0, T0)] | SBOX2[get_byte(1, T0)] |
+            SBOX3[get_byte(2, T0)] | SBOX4[get_byte(3, T0)];
+
+      T0 = N2 + EK[30-j];
+      N1 ^= SBOX1[get_byte(0, T0)] | SBOX2[get_byte(1, T0)] |
+            SBOX3[get_byte(2, T0)] | SBOX4[get_byte(3, T0)];
+      }
+
+   out[0] = get_byte(3, N2); out[1] = get_byte(2, N2);
+   out[2] = get_byte(1, N2); out[3] = get_byte(0, N2);
+   out[4] = get_byte(3, N1); out[5] = get_byte(2, N1);
+   out[6] = get_byte(1, N1); out[7] = get_byte(0, N1);
+   }
+
+/*************************************************
+* GOST Key Schedule                              *
+*************************************************/
+void GOST::key(const byte key[], u32bit)
+   {
+   for(u32bit j = 0; j != 8; ++j)
+      {
+      u32bit K = make_u32bit(key[4*j+3], key[4*j+2], key[4*j+1], key[4*j]);
+      EK[j] = EK[j+8] = EK[j+16] = K;
+      }
+
+   for(u32bit j = 24; j != 32; ++j)
+      EK[j] = EK[7-(j-24)];
+   }
+
+}