From fcca1ab049978ae66a3dfeff5e4704fa8127095e Mon Sep 17 00:00:00 2001 From: Mark Fedorov Date: Fri, 1 Jul 2022 15:29:12 +0300 Subject: [PATCH] Refactor little-to-big-endian subroutine for magma --- gost89.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++ gost89.h | 4 ++ gost_crypt.c | 34 +++++----------- 3 files changed, 121 insertions(+), 24 deletions(-) diff --git a/gost89.c b/gost89.c index 90d5515..240bc7a 100644 --- a/gost89.c +++ b/gost89.c @@ -328,6 +328,60 @@ void gostcrypt(gost_ctx * c, const byte * in, byte * out) out[7] = (byte) (n1 >> 24); } +/* Low-level encryption routine - encrypts one 64 bit block*/ +void magmacrypt(gost_ctx * c, const byte * in, byte * out) +{ + register word32 n1, n2; /* As named in the GOST */ + n1 = in[7-0] | (in[7-1] << 8) | (in[7-2] << 16) | ((word32) in[7-3] << 24); + n2 = in[7-4] | (in[7-5] << 8) | (in[7-6] << 16) | ((word32) in[7-7] << 24); + /* Instead of swapping halves, swap names each round */ + + n2 ^= f(c, n1 + c->key[0] + c->mask[0]); + n1 ^= f(c, n2 + c->key[1] + c->mask[1]); + n2 ^= f(c, n1 + c->key[2] + c->mask[2]); + n1 ^= f(c, n2 + c->key[3] + c->mask[3]); + n2 ^= f(c, n1 + c->key[4] + c->mask[4]); + n1 ^= f(c, n2 + c->key[5] + c->mask[5]); + n2 ^= f(c, n1 + c->key[6] + c->mask[6]); + n1 ^= f(c, n2 + c->key[7] + c->mask[7]); + + n2 ^= f(c, n1 + c->key[0] + c->mask[0]); + n1 ^= f(c, n2 + c->key[1] + c->mask[1]); + n2 ^= f(c, n1 + c->key[2] + c->mask[2]); + n1 ^= f(c, n2 + c->key[3] + c->mask[3]); + n2 ^= f(c, n1 + c->key[4] + c->mask[4]); + n1 ^= f(c, n2 + c->key[5] + c->mask[5]); + n2 ^= f(c, n1 + c->key[6] + c->mask[6]); + n1 ^= f(c, n2 + c->key[7] + c->mask[7]); + + n2 ^= f(c, n1 + c->key[0] + c->mask[0]); + n1 ^= f(c, n2 + c->key[1] + c->mask[1]); + n2 ^= f(c, n1 + c->key[2] + c->mask[2]); + n1 ^= f(c, n2 + c->key[3] + c->mask[3]); + n2 ^= f(c, n1 + c->key[4] + c->mask[4]); + n1 ^= f(c, n2 + c->key[5] + c->mask[5]); + n2 ^= f(c, n1 + c->key[6] + c->mask[6]); + n1 ^= f(c, n2 + c->key[7] + c->mask[7]); + + n2 ^= f(c, n1 + c->key[7] + c->mask[7]); + n1 ^= f(c, n2 + c->key[6] + c->mask[6]); + n2 ^= f(c, n1 + c->key[5] + c->mask[5]); + n1 ^= f(c, n2 + c->key[4] + c->mask[4]); + n2 ^= f(c, n1 + c->key[3] + c->mask[3]); + n1 ^= f(c, n2 + c->key[2] + c->mask[2]); + n2 ^= f(c, n1 + c->key[1] + c->mask[1]); + n1 ^= f(c, n2 + c->key[0] + c->mask[0]); + + out[7-0] = (byte) (n2 & 0xff); + out[7-1] = (byte) ((n2 >> 8) & 0xff); + out[7-2] = (byte) ((n2 >> 16) & 0xff); + out[7-3] = (byte) (n2 >> 24); + out[7-4] = (byte) (n1 & 0xff); + out[7-5] = (byte) ((n1 >> 8) & 0xff); + out[7-6] = (byte) ((n1 >> 16) & 0xff); + out[7-7] = (byte) (n1 >> 24); +} + /* Low-level decryption routine. Decrypts one 64-bit block */ void gostdecrypt(gost_ctx * c, const byte * in, byte * out) { @@ -381,6 +435,59 @@ void gostdecrypt(gost_ctx * c, const byte * in, byte * out) out[7] = (byte) (n1 >> 24); } +/* Low-level decryption routine. Decrypts one 64-bit block */ +void magmadecrypt(gost_ctx * c, const byte * in, byte * out) +{ + register word32 n1, n2; /* As named in the GOST */ + n1 = in[7-0] | (in[7-1] << 8) | (in[7-2] << 16) | ((word32) in[7-3] << 24); + n2 = in[7-4] | (in[7-5] << 8) | (in[7-6] << 16) | ((word32) in[7-7] << 24); + + n2 ^= f(c, n1 + c->key[0] + c->mask[0]); + n1 ^= f(c, n2 + c->key[1] + c->mask[1]); + n2 ^= f(c, n1 + c->key[2] + c->mask[2]); + n1 ^= f(c, n2 + c->key[3] + c->mask[3]); + n2 ^= f(c, n1 + c->key[4] + c->mask[4]); + n1 ^= f(c, n2 + c->key[5] + c->mask[5]); + n2 ^= f(c, n1 + c->key[6] + c->mask[6]); + n1 ^= f(c, n2 + c->key[7] + c->mask[7]); + + n2 ^= f(c, n1 + c->key[7] + c->mask[7]); + n1 ^= f(c, n2 + c->key[6] + c->mask[6]); + n2 ^= f(c, n1 + c->key[5] + c->mask[5]); + n1 ^= f(c, n2 + c->key[4] + c->mask[4]); + n2 ^= f(c, n1 + c->key[3] + c->mask[3]); + n1 ^= f(c, n2 + c->key[2] + c->mask[2]); + n2 ^= f(c, n1 + c->key[1] + c->mask[1]); + n1 ^= f(c, n2 + c->key[0] + c->mask[0]); + + n2 ^= f(c, n1 + c->key[7] + c->mask[7]); + n1 ^= f(c, n2 + c->key[6] + c->mask[6]); + n2 ^= f(c, n1 + c->key[5] + c->mask[5]); + n1 ^= f(c, n2 + c->key[4] + c->mask[4]); + n2 ^= f(c, n1 + c->key[3] + c->mask[3]); + n1 ^= f(c, n2 + c->key[2] + c->mask[2]); + n2 ^= f(c, n1 + c->key[1] + c->mask[1]); + n1 ^= f(c, n2 + c->key[0] + c->mask[0]); + + n2 ^= f(c, n1 + c->key[7] + c->mask[7]); + n1 ^= f(c, n2 + c->key[6] + c->mask[6]); + n2 ^= f(c, n1 + c->key[5] + c->mask[5]); + n1 ^= f(c, n2 + c->key[4] + c->mask[4]); + n2 ^= f(c, n1 + c->key[3] + c->mask[3]); + n1 ^= f(c, n2 + c->key[2] + c->mask[2]); + n2 ^= f(c, n1 + c->key[1] + c->mask[1]); + n1 ^= f(c, n2 + c->key[0] + c->mask[0]); + + out[7-0] = (byte) (n2 & 0xff); + out[7-1] = (byte) ((n2 >> 8) & 0xff); + out[7-2] = (byte) ((n2 >> 16) & 0xff); + out[7-3] = (byte) (n2 >> 24); + out[7-4] = (byte) (n1 & 0xff); + out[7-5] = (byte) ((n1 >> 8) & 0xff); + out[7-6] = (byte) ((n1 >> 16) & 0xff); + out[7-7] = (byte) (n1 >> 24); +} + /* Encrypts several blocks in ECB mode */ void gost_enc(gost_ctx * c, const byte * clear, byte * cipher, int blocks) diff --git a/gost89.h b/gost89.h index f201363..f8a83bb 100644 --- a/gost89.h +++ b/gost89.h @@ -59,6 +59,10 @@ void gost_dec_cfb(gost_ctx * ctx, const byte * iv, const byte * cipher, void gostcrypt(gost_ctx * c, const byte * in, byte * out); /* Decrypt one block */ void gostdecrypt(gost_ctx * c, const byte * in, byte * out); +/* Encrypt one block */ +void magmacrypt(gost_ctx * c, const byte * in, byte * out); +/* Decrypt one block */ +void magmadecrypt(gost_ctx * c, const byte * in, byte * out); /* Set key into context */ void gost_key(gost_ctx * c, const byte * k); /* Set key into context without key mask */ diff --git a/gost_crypt.c b/gost_crypt.c index 8f8e0d3..6d68f62 100644 --- a/gost_crypt.c +++ b/gost_crypt.c @@ -607,13 +607,9 @@ static int magma_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out, while (inl > 0) { for (i = 0; i < 8; i++) { - b[7 - i] = iv[i] ^ in_ptr[i]; - } - gostcrypt(&(c->cctx), b, d); - - for (i = 0; i < 8; i++) { - out_ptr[7 - i] = d[i]; + out_ptr[i] = iv[i] ^ in_ptr[i]; } + magmacrypt(&(c->cctx), out_ptr, out_ptr); memcpy(iv, out_ptr, 8); out_ptr += 8; in_ptr += 8; @@ -621,13 +617,10 @@ static int magma_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out, } } else { while (inl > 0) { - for (i = 0; i < 8; i++) { - d[7 - i] = in_ptr[i]; - } - gostdecrypt(&(c->cctx), d, b); + magmadecrypt(&(c->cctx), in_ptr, b); memcpy(d, in_ptr, 8); for (i = 0; i < 8; i++) { - out_ptr[i] = iv[i] ^ b[7 - i]; + out_ptr[i] = iv[i] ^ b[i]; } memcpy(iv, d, 8); out_ptr += 8; @@ -667,10 +660,9 @@ static int magma_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out, unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx); unsigned int num = EVP_CIPHER_CTX_num(ctx); size_t blocks, i, lasted = inl; - unsigned char b[8]; /* Process partial blocks */ while ((num & MAGMA_BLOCK_MASK) && lasted) { - *out_ptr++ = *in_ptr++ ^ buf[7 - (num & MAGMA_BLOCK_MASK)]; + *out_ptr++ = *in_ptr++ ^ buf[num & MAGMA_BLOCK_MASK]; --lasted; num++; } @@ -679,12 +671,9 @@ static int magma_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out, /* Process full blocks */ for (i = 0; i < blocks; i++) { apply_acpkm_magma(c, &num); + magmacrypt(&(c->cctx), iv, buf); for (j = 0; j < 8; j++) { - b[7 - j] = iv[j]; - } - gostcrypt(&(c->cctx), b, buf); - for (j = 0; j < 8; j++) { - out_ptr[j] = buf[7 - j] ^ in_ptr[j]; + out_ptr[j] = buf[j] ^ in_ptr[j]; } ctr64_inc(iv); c->count += MAGMA_BLOCK_SIZE; @@ -697,15 +686,12 @@ static int magma_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out, /* Process the rest of plaintext */ if (lasted > 0) { apply_acpkm_magma(c, &num); - for (j = 0; j < 8; j++) { - b[7 - j] = iv[j]; - } - gostcrypt(&(c->cctx), b, buf); + magmacrypt(&(c->cctx), iv, buf); for (i = 0; i < lasted; i++) - out_ptr[i] = buf[7 - i] ^ in_ptr[i]; + out_ptr[i] = buf[i] ^ in_ptr[i]; ctr64_inc(iv); - c->count += j; + c->count += 8; num += lasted; } EVP_CIPHER_CTX_set_num(ctx, num); -- 2.39.5