diff options
| -rw-r--r-- | src/block/gost_28147/gost_28147.cpp | 74 | ||||
| -rw-r--r-- | src/block/gost_28147/gost_28147.h | 2 |
2 files changed, 40 insertions, 36 deletions
diff --git a/src/block/gost_28147/gost_28147.cpp b/src/block/gost_28147/gost_28147.cpp index 0f29102de..d433924fc 100644 --- a/src/block/gost_28147/gost_28147.cpp +++ b/src/block/gost_28147/gost_28147.cpp @@ -37,29 +37,43 @@ GOST_28147_89::GOST_28147_89() : BlockCipher(8, 32) } /* +* Two rounds of GOST +*/ +#define GOST_2ROUND(N1, N2, R1, R2) \ + { \ + u32bit T0 = N1 + EK[R1]; \ + N2 ^= SBOX[get_byte(3, T0)] | \ + SBOX[get_byte(2, T0)+256] | \ + SBOX[get_byte(1, T0)+512] | \ + SBOX[get_byte(0, T0)+768]; \ + \ + T0 = N2 + EK[R2]; \ + N1 ^= SBOX[get_byte(3, T0)] | \ + SBOX[get_byte(2, T0)+256] | \ + SBOX[get_byte(1, T0)+512] | \ + SBOX[get_byte(0, T0)+768]; \ + } + +/* * GOST Encryption */ void GOST_28147_89::enc(const byte in[], byte out[]) const { u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1); - for(u32bit j = 0; j != 32; j += 2) + for(size_t i = 0; i != 3; ++i) { - u32bit T0; - - T0 = N1 + EK[j]; - N2 ^= SBOX[get_byte(3, T0)] | - SBOX[get_byte(2, T0)+256] | - SBOX[get_byte(1, T0)+512] | - SBOX[get_byte(0, T0)+768]; - - T0 = N2 + EK[j+1]; - N1 ^= SBOX[get_byte(3, T0)] | - SBOX[get_byte(2, T0)+256] | - SBOX[get_byte(1, T0)+512] | - SBOX[get_byte(0, T0)+768]; + GOST_2ROUND(N1, N2, 0, 1); + GOST_2ROUND(N1, N2, 2, 3); + GOST_2ROUND(N1, N2, 4, 5); + GOST_2ROUND(N1, N2, 6, 7); } + GOST_2ROUND(N1, N2, 7, 6); + GOST_2ROUND(N1, N2, 5, 4); + GOST_2ROUND(N1, N2, 3, 2); + GOST_2ROUND(N1, N2, 1, 0); + store_le(out, N2, N1); } @@ -70,21 +84,17 @@ void GOST_28147_89::dec(const byte in[], byte out[]) const { u32bit N1 = load_le<u32bit>(in, 0), N2 = load_le<u32bit>(in, 1); - for(u32bit j = 0; j != 32; j += 2) + GOST_2ROUND(N1, N2, 0, 1); + GOST_2ROUND(N1, N2, 2, 3); + GOST_2ROUND(N1, N2, 4, 5); + GOST_2ROUND(N1, N2, 6, 7); + + for(size_t i = 0; i != 3; ++i) { - u32bit T0; - - T0 = N1 + EK[31-j]; - N2 ^= SBOX[get_byte(3, T0)] | - SBOX[get_byte(2, T0)+256] | - SBOX[get_byte(1, T0)+512] | - SBOX[get_byte(0, T0)+768]; - - T0 = N2 + EK[30-j]; - N1 ^= SBOX[get_byte(3, T0)] | - SBOX[get_byte(2, T0)+256] | - SBOX[get_byte(1, T0)+512] | - SBOX[get_byte(0, T0)+768]; + GOST_2ROUND(N1, N2, 7, 6); + GOST_2ROUND(N1, N2, 5, 4); + GOST_2ROUND(N1, N2, 3, 2); + GOST_2ROUND(N1, N2, 1, 0); } store_le(out, N2, N1); @@ -96,13 +106,7 @@ void GOST_28147_89::dec(const byte in[], byte out[]) const void GOST_28147_89::key_schedule(const byte key[], u32bit) { for(u32bit j = 0; j != 8; ++j) - { - u32bit K = load_le<u32bit>(key, j); - EK[j] = EK[j+8] = EK[j+16] = K; - } - - for(u32bit j = 24; j != 32; ++j) - EK[j] = EK[7-(j-24)]; + EK[j] = load_le<u32bit>(key, j); } } diff --git a/src/block/gost_28147/gost_28147.h b/src/block/gost_28147/gost_28147.h index a58927e28..1ff04b890 100644 --- a/src/block/gost_28147/gost_28147.h +++ b/src/block/gost_28147/gost_28147.h @@ -30,7 +30,7 @@ class BOTAN_DLL GOST_28147_89 : public BlockCipher void key_schedule(const byte[], u32bit); SecureBuffer<u32bit, 1024> SBOX; - SecureBuffer<u32bit, 32> EK; + SecureBuffer<u32bit, 8> EK; }; } |