/********************************************************************** * gost89.c * * Copyright (c) 2005-2006 Cryptocom LTD * * This file is distributed under the same license as OpenSSL * * * * Implementation of GOST 28147-89 encryption algorithm * * No OpenSSL libraries required to compile and use * * this code * **********************************************************************/ #include #include "gost89.h" /*- Substitution blocks from RFC 4357 Note: our implementation of gost 28147-89 algorithm uses S-box matrix rotated 90 degrees counterclockwise, relative to examples given in RFC. */ /* Substitution blocks from test examples for GOST R 34.11-94*/ gost_subst_block GostR3411_94_TestParamSet = { {0X1, 0XF, 0XD, 0X0, 0X5, 0X7, 0XA, 0X4, 0X9, 0X2, 0X3, 0XE, 0X6, 0XB, 0X8, 0XC} , {0XD, 0XB, 0X4, 0X1, 0X3, 0XF, 0X5, 0X9, 0X0, 0XA, 0XE, 0X7, 0X6, 0X8, 0X2, 0XC} , {0X4, 0XB, 0XA, 0X0, 0X7, 0X2, 0X1, 0XD, 0X3, 0X6, 0X8, 0X5, 0X9, 0XC, 0XF, 0XE} , {0X6, 0XC, 0X7, 0X1, 0X5, 0XF, 0XD, 0X8, 0X4, 0XA, 0X9, 0XE, 0X0, 0X3, 0XB, 0X2} , {0X7, 0XD, 0XA, 0X1, 0X0, 0X8, 0X9, 0XF, 0XE, 0X4, 0X6, 0XC, 0XB, 0X2, 0X5, 0X3} , {0X5, 0X8, 0X1, 0XD, 0XA, 0X3, 0X4, 0X2, 0XE, 0XF, 0XC, 0X7, 0X6, 0X0, 0X9, 0XB} , {0XE, 0XB, 0X4, 0XC, 0X6, 0XD, 0XF, 0XA, 0X2, 0X3, 0X8, 0X1, 0X0, 0X7, 0X5, 0X9} , {0X4, 0XA, 0X9, 0X2, 0XD, 0X8, 0X0, 0XE, 0X6, 0XB, 0X1, 0XC, 0X7, 0XF, 0X5, 0X3} }; /* Substitution blocks for hash function 1.2.643.2.9.1.6.1 */ gost_subst_block GostR3411_94_CryptoProParamSet = { {0x1, 0x3, 0xA, 0x9, 0x5, 0xB, 0x4, 0xF, 0x8, 0x6, 0x7, 0xE, 0xD, 0x0, 0x2, 0xC} , {0xD, 0xE, 0x4, 0x1, 0x7, 0x0, 0x5, 0xA, 0x3, 0xC, 0x8, 0xF, 0x6, 0x2, 0x9, 0xB} , {0x7, 0x6, 0x2, 0x4, 0xD, 0x9, 0xF, 0x0, 0xA, 0x1, 0x5, 0xB, 0x8, 0xE, 0xC, 0x3} , {0x7, 0x6, 0x4, 0xB, 0x9, 0xC, 0x2, 0xA, 0x1, 0x8, 0x0, 0xE, 0xF, 0xD, 0x3, 0x5} , {0x4, 0xA, 0x7, 0xC, 0x0, 0xF, 0x2, 0x8, 0xE, 0x1, 0x6, 0x5, 0xD, 0xB, 0x9, 0x3} , {0x7, 0xF, 0xC, 0xE, 0x9, 0x4, 0x1, 0x0, 0x3, 0xB, 0x5, 0x2, 0x6, 0xA, 0x8, 0xD} , {0x5, 0xF, 0x4, 0x0, 0x2, 0xD, 0xB, 0x9, 0x1, 0x7, 0x6, 0x3, 0xC, 0xE, 0xA, 0x8} , {0xA, 0x4, 0x5, 0x6, 0x8, 0x1, 0x3, 0x7, 0xD, 0xC, 0xE, 0x0, 0x9, 0x2, 0xB, 0xF} }; /* Test paramset from GOST 28147 */ gost_subst_block Gost28147_TestParamSet = { {0xC, 0x6, 0x5, 0x2, 0xB, 0x0, 0x9, 0xD, 0x3, 0xE, 0x7, 0xA, 0xF, 0x4, 0x1, 0x8} , {0x9, 0xB, 0xC, 0x0, 0x3, 0x6, 0x7, 0x5, 0x4, 0x8, 0xE, 0xF, 0x1, 0xA, 0x2, 0xD} , {0x8, 0xF, 0x6, 0xB, 0x1, 0x9, 0xC, 0x5, 0xD, 0x3, 0x7, 0xA, 0x0, 0xE, 0x2, 0x4} , {0x3, 0xE, 0x5, 0x9, 0x6, 0x8, 0x0, 0xD, 0xA, 0xB, 0x7, 0xC, 0x2, 0x1, 0xF, 0x4} , {0xE, 0x9, 0xB, 0x2, 0x5, 0xF, 0x7, 0x1, 0x0, 0xD, 0xC, 0x6, 0xA, 0x4, 0x3, 0x8} , {0xD, 0x8, 0xE, 0xC, 0x7, 0x3, 0x9, 0xA, 0x1, 0x5, 0x2, 0x4, 0x6, 0xF, 0x0, 0xB} , {0xC, 0x9, 0xF, 0xE, 0x8, 0x1, 0x3, 0xA, 0x2, 0x7, 0x4, 0xD, 0x6, 0x0, 0xB, 0x5} , {0x4, 0x2, 0xF, 0x5, 0x9, 0x1, 0x0, 0x8, 0xE, 0x3, 0xB, 0xC, 0xD, 0x7, 0xA, 0x6} }; /* 1.2.643.2.2.31.1 */ gost_subst_block Gost28147_CryptoProParamSetA = { {0xB, 0xA, 0xF, 0x5, 0x0, 0xC, 0xE, 0x8, 0x6, 0x2, 0x3, 0x9, 0x1, 0x7, 0xD, 0x4} , {0x1, 0xD, 0x2, 0x9, 0x7, 0xA, 0x6, 0x0, 0x8, 0xC, 0x4, 0x5, 0xF, 0x3, 0xB, 0xE} , {0x3, 0xA, 0xD, 0xC, 0x1, 0x2, 0x0, 0xB, 0x7, 0x5, 0x9, 0x4, 0x8, 0xF, 0xE, 0x6} , {0xB, 0x5, 0x1, 0x9, 0x8, 0xD, 0xF, 0x0, 0xE, 0x4, 0x2, 0x3, 0xC, 0x7, 0xA, 0x6} , {0xE, 0x7, 0xA, 0xC, 0xD, 0x1, 0x3, 0x9, 0x0, 0x2, 0xB, 0x4, 0xF, 0x8, 0x5, 0x6} , {0xE, 0x4, 0x6, 0x2, 0xB, 0x3, 0xD, 0x8, 0xC, 0xF, 0x5, 0xA, 0x0, 0x7, 0x1, 0x9} , {0x3, 0x7, 0xE, 0x9, 0x8, 0xA, 0xF, 0x0, 0x5, 0x2, 0x6, 0xC, 0xB, 0x4, 0xD, 0x1} , {0x9, 0x6, 0x3, 0x2, 0x8, 0xB, 0x1, 0x7, 0xA, 0x4, 0xE, 0xF, 0xC, 0x0, 0xD, 0x5} }; /* 1.2.643.2.2.31.2 */ gost_subst_block Gost28147_CryptoProParamSetB = { {0x0, 0x4, 0xB, 0xE, 0x8, 0x3, 0x7, 0x1, 0xA, 0x2, 0x9, 0x6, 0xF, 0xD, 0x5, 0xC} , {0x5, 0x2, 0xA, 0xB, 0x9, 0x1, 0xC, 0x3, 0x7, 0x4, 0xD, 0x0, 0x6, 0xF, 0x8, 0xE} , {0x8, 0x3, 0x2, 0x6, 0x4, 0xD, 0xE, 0xB, 0xC, 0x1, 0x7, 0xF, 0xA, 0x0, 0x9, 0x5} , {0x2, 0x7, 0xC, 0xF, 0x9, 0x5, 0xA, 0xB, 0x1, 0x4, 0x0, 0xD, 0x6, 0x8, 0xE, 0x3} , {0x7, 0x5, 0x0, 0xD, 0xB, 0x6, 0x1, 0x2, 0x3, 0xA, 0xC, 0xF, 0x4, 0xE, 0x9, 0x8} , {0xE, 0xC, 0x0, 0xA, 0x9, 0x2, 0xD, 0xB, 0x7, 0x5, 0x8, 0xF, 0x3, 0x6, 0x1, 0x4} , {0x0, 0x1, 0x2, 0xA, 0x4, 0xD, 0x5, 0xC, 0x9, 0x7, 0x3, 0xF, 0xB, 0x8, 0x6, 0xE} , {0x8, 0x4, 0xB, 0x1, 0x3, 0x5, 0x0, 0x9, 0x2, 0xE, 0xA, 0xC, 0xD, 0x6, 0x7, 0xF} }; /* 1.2.643.2.2.31.3 */ gost_subst_block Gost28147_CryptoProParamSetC = { {0x7, 0x4, 0x0, 0x5, 0xA, 0x2, 0xF, 0xE, 0xC, 0x6, 0x1, 0xB, 0xD, 0x9, 0x3, 0x8} , {0xA, 0x9, 0x6, 0x8, 0xD, 0xE, 0x2, 0x0, 0xF, 0x3, 0x5, 0xB, 0x4, 0x1, 0xC, 0x7} , {0xC, 0x9, 0xB, 0x1, 0x8, 0xE, 0x2, 0x4, 0x7, 0x3, 0x6, 0x5, 0xA, 0x0, 0xF, 0xD} , {0x8, 0xD, 0xB, 0x0, 0x4, 0x5, 0x1, 0x2, 0x9, 0x3, 0xC, 0xE, 0x6, 0xF, 0xA, 0x7} , {0x3, 0x6, 0x0, 0x1, 0x5, 0xD, 0xA, 0x8, 0xB, 0x2, 0x9, 0x7, 0xE, 0xF, 0xC, 0x4} , {0x8, 0x2, 0x5, 0x0, 0x4, 0x9, 0xF, 0xA, 0x3, 0x7, 0xC, 0xD, 0x6, 0xE, 0x1, 0xB} , {0x0, 0x1, 0x7, 0xD, 0xB, 0x4, 0x5, 0x2, 0x8, 0xE, 0xF, 0xC, 0x9, 0xA, 0x6, 0x3} , {0x1, 0xB, 0xC, 0x2, 0x9, 0xD, 0x0, 0xF, 0x4, 0x5, 0x8, 0xE, 0xA, 0x7, 0x6, 0x3} }; /* 1.2.643.2.2.31.4 */ gost_subst_block Gost28147_CryptoProParamSetD = { {0x1, 0xA, 0x6, 0x8, 0xF, 0xB, 0x0, 0x4, 0xC, 0x3, 0x5, 0x9, 0x7, 0xD, 0x2, 0xE} , {0x3, 0x0, 0x6, 0xF, 0x1, 0xE, 0x9, 0x2, 0xD, 0x8, 0xC, 0x4, 0xB, 0xA, 0x5, 0x7} , {0x8, 0x0, 0xF, 0x3, 0x2, 0x5, 0xE, 0xB, 0x1, 0xA, 0x4, 0x7, 0xC, 0x9, 0xD, 0x6} , {0x0, 0xC, 0x8, 0x9, 0xD, 0x2, 0xA, 0xB, 0x7, 0x3, 0x6, 0x5, 0x4, 0xE, 0xF, 0x1} , {0x1, 0x5, 0xE, 0xC, 0xA, 0x7, 0x0, 0xD, 0x6, 0x2, 0xB, 0x4, 0x9, 0x3, 0xF, 0x8} , {0x1, 0xC, 0xB, 0x0, 0xF, 0xE, 0x6, 0x5, 0xA, 0xD, 0x4, 0x8, 0x9, 0x3, 0x7, 0x2} , {0xB, 0x6, 0x3, 0x4, 0xC, 0xF, 0xE, 0x2, 0x7, 0xD, 0x8, 0x0, 0x5, 0xA, 0x9, 0x1} , {0xF, 0xC, 0x2, 0xA, 0x6, 0x4, 0x5, 0x0, 0x7, 0x9, 0xE, 0xD, 0x1, 0xB, 0x8, 0x3} }; const byte CryptoProKeyMeshingKey[] = { 0x69, 0x00, 0x72, 0x22, 0x64, 0xC9, 0x04, 0x23, 0x8D, 0x3A, 0xDB, 0x96, 0x46, 0xE9, 0x2A, 0xC4, 0x18, 0xFE, 0xAC, 0x94, 0x00, 0xED, 0x07, 0x12, 0xC0, 0x86, 0xDC, 0xC2, 0xEF, 0x4C, 0xA9, 0x2B }; /* Initialization of gost_ctx subst blocks*/ static void kboxinit(gost_ctx * c, const gost_subst_block * b) { int i; for (i = 0; i < 256; i++) { c->k87[i] = (b->k8[i >> 4] << 4 | b->k7[i & 15]) << 24; c->k65[i] = (b->k6[i >> 4] << 4 | b->k5[i & 15]) << 16; c->k43[i] = (b->k4[i >> 4] << 4 | b->k3[i & 15]) << 8; c->k21[i] = b->k2[i >> 4] << 4 | b->k1[i & 15]; } } /* Part of GOST 28147 algorithm moved into separate function */ static word32 f(gost_ctx * c, word32 x) { x = c->k87[x >> 24 & 255] | c->k65[x >> 16 & 255] | c->k43[x >> 8 & 255] | c->k21[x & 255]; /* Rotate left 11 bits */ return x << 11 | x >> (32 - 11); } /* Low-level encryption routine - encrypts one 64 bit block*/ void gostcrypt(gost_ctx * c, const byte * in, byte * out) { register word32 n1, n2; /* As named in the GOST */ n1 = in[0] | (in[1] << 8) | (in[2] << 16) | (in[3] << 24); n2 = in[4] | (in[5] << 8) | (in[6] << 16) | (in[7] << 24); /* Instead of swapping halves, swap names each round */ n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); n2 ^= f(c, n1 + c->k[7]); n1 ^= f(c, n2 + c->k[6]); n2 ^= f(c, n1 + c->k[5]); n1 ^= f(c, n2 + c->k[4]); n2 ^= f(c, n1 + c->k[3]); n1 ^= f(c, n2 + c->k[2]); n2 ^= f(c, n1 + c->k[1]); n1 ^= f(c, n2 + c->k[0]); out[0] = (byte) (n2 & 0xff); out[1] = (byte) ((n2 >> 8) & 0xff); out[2] = (byte) ((n2 >> 16) & 0xff); out[3] = (byte) (n2 >> 24); out[4] = (byte) (n1 & 0xff); out[5] = (byte) ((n1 >> 8) & 0xff); out[6] = (byte) ((n1 >> 16) & 0xff); out[7] = (byte) (n1 >> 24); } /* Low-level decryption routine. Decrypts one 64-bit block */ void gostdecrypt(gost_ctx * c, const byte * in, byte * out) { register word32 n1, n2; /* As named in the GOST */ n1 = in[0] | (in[1] << 8) | (in[2] << 16) | (in[3] << 24); n2 = in[4] | (in[5] << 8) | (in[6] << 16) | (in[7] << 24); n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); n2 ^= f(c, n1 + c->k[7]); n1 ^= f(c, n2 + c->k[6]); n2 ^= f(c, n1 + c->k[5]); n1 ^= f(c, n2 + c->k[4]); n2 ^= f(c, n1 + c->k[3]); n1 ^= f(c, n2 + c->k[2]); n2 ^= f(c, n1 + c->k[1]); n1 ^= f(c, n2 + c->k[0]); n2 ^= f(c, n1 + c->k[7]); n1 ^= f(c, n2 + c->k[6]); n2 ^= f(c, n1 + c->k[5]); n1 ^= f(c, n2 + c->k[4]); n2 ^= f(c, n1 + c->k[3]); n1 ^= f(c, n2 + c->k[2]); n2 ^= f(c, n1 + c->k[1]); n1 ^= f(c, n2 + c->k[0]); n2 ^= f(c, n1 + c->k[7]); n1 ^= f(c, n2 + c->k[6]); n2 ^= f(c, n1 + c->k[5]); n1 ^= f(c, n2 + c->k[4]); n2 ^= f(c, n1 + c->k[3]); n1 ^= f(c, n2 + c->k[2]); n2 ^= f(c, n1 + c->k[1]); n1 ^= f(c, n2 + c->k[0]); out[0] = (byte) (n2 & 0xff); out[1] = (byte) ((n2 >> 8) & 0xff); out[2] = (byte) ((n2 >> 16) & 0xff); out[3] = (byte) (n2 >> 24); out[4] = (byte) (n1 & 0xff); out[5] = (byte) ((n1 >> 8) & 0xff); out[6] = (byte) ((n1 >> 16) & 0xff); out[7] = (byte) (n1 >> 24); } /* Encrypts several blocks in ECB mode */ void gost_enc(gost_ctx * c, const byte * clear, byte * cipher, int blocks) { int i; for (i = 0; i < blocks; i++) { gostcrypt(c, clear, cipher); clear += 8; cipher += 8; } } /* Decrypts several blocks in ECB mode */ void gost_dec(gost_ctx * c, const byte * cipher, byte * clear, int blocks) { int i; for (i = 0; i < blocks; i++) { gostdecrypt(c, cipher, clear); clear += 8; cipher += 8; } } /* Encrypts several full blocks in CFB mode using 8byte IV */ void gost_enc_cfb(gost_ctx * ctx, const byte * iv, const byte * clear, byte * cipher, int blocks) { byte cur_iv[8]; byte gamma[8]; int i, j; const byte *in; byte *out; memcpy(cur_iv, iv, 8); for (i = 0, in = clear, out = cipher; i < blocks; i++, in += 8, out += 8) { gostcrypt(ctx, cur_iv, gamma); for (j = 0; j < 8; j++) { cur_iv[j] = out[j] = in[j] ^ gamma[j]; } } } /* Decrypts several full blocks in CFB mode using 8byte IV */ void gost_dec_cfb(gost_ctx * ctx, const byte * iv, const byte * cipher, byte * clear, int blocks) { byte cur_iv[8]; byte gamma[8]; int i, j; const byte *in; byte *out; memcpy(cur_iv, iv, 8); for (i = 0, in = cipher, out = clear; i < blocks; i++, in += 8, out += 8) { gostcrypt(ctx, cur_iv, gamma); for (j = 0; j < 8; j++) { out[j] = (cur_iv[j] = in[j]) ^ gamma[j]; } } } /* Encrypts one block using specified key */ void gost_enc_with_key(gost_ctx * c, byte * key, byte * inblock, byte * outblock) { gost_key(c, key); gostcrypt(c, inblock, outblock); } /* Set 256 bit key into context */ void gost_key(gost_ctx * c, const byte * k) { int i, j; for (i = 0, j = 0; i < 8; i++, j += 4) { c->k[i] = k[j] | (k[j + 1] << 8) | (k[j + 2] << 16) | (k[j + 3] << 24); } } /* Retrieve 256-bit key from context */ void gost_get_key(gost_ctx * c, byte * k) { int i, j; for (i = 0, j = 0; i < 8; i++, j += 4) { k[j] = (byte) (c->k[i] & 0xFF); k[j + 1] = (byte) ((c->k[i] >> 8) & 0xFF); k[j + 2] = (byte) ((c->k[i] >> 16) & 0xFF); k[j + 3] = (byte) ((c->k[i] >> 24) & 0xFF); } } /* Initalize context. Provides default value for subst_block */ void gost_init(gost_ctx * c, const gost_subst_block * b) { if (!b) { b = &GostR3411_94_TestParamSet; } kboxinit(c, b); } /* Cleans up key from context */ void gost_destroy(gost_ctx * c) { int i; for (i = 0; i < 8; i++) c->k[i] = 0; } /* * Compute GOST 28147 mac block Parameters gost_ctx *c - context initalized * with substitution blocks and key buffer - 8-byte mac state buffer block * 8-byte block to process. */ void mac_block(gost_ctx * c, byte * buffer, const byte * block) { register word32 n1, n2; /* As named in the GOST */ int i; for (i = 0; i < 8; i++) { buffer[i] ^= block[i]; } n1 = buffer[0] | (buffer[1] << 8) | (buffer[2] << 16) | (buffer[3] << 24); n2 = buffer[4] | (buffer[5] << 8) | (buffer[6] << 16) | (buffer[7] << 24); /* Instead of swapping halves, swap names each round */ n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); n2 ^= f(c, n1 + c->k[0]); n1 ^= f(c, n2 + c->k[1]); n2 ^= f(c, n1 + c->k[2]); n1 ^= f(c, n2 + c->k[3]); n2 ^= f(c, n1 + c->k[4]); n1 ^= f(c, n2 + c->k[5]); n2 ^= f(c, n1 + c->k[6]); n1 ^= f(c, n2 + c->k[7]); buffer[0] = (byte) (n1 & 0xff); buffer[1] = (byte) ((n1 >> 8) & 0xff); buffer[2] = (byte) ((n1 >> 16) & 0xff); buffer[3] = (byte) (n1 >> 24); buffer[4] = (byte) (n2 & 0xff); buffer[5] = (byte) ((n2 >> 8) & 0xff); buffer[6] = (byte) ((n2 >> 16) & 0xff); buffer[7] = (byte) (n2 >> 24); } /* Get mac with specified number of bits from MAC state buffer */ void get_mac(byte * buffer, int nbits, byte * out) { int nbytes = nbits >> 3; int rembits = nbits & 7; int mask = rembits ? ((1 < rembits) - 1) : 0; int i; for (i = 0; i < nbytes; i++) out[i] = buffer[i]; if (rembits) out[i] = buffer[i] & mask; } /* * Compute mac of specified length (in bits) from data. Context should be * initialized with key and subst blocks */ int gost_mac(gost_ctx * ctx, int mac_len, const unsigned char *data, unsigned int data_len, unsigned char *mac) { byte buffer[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; byte buf2[8]; unsigned int i; for (i = 0; i + 8 <= data_len; i += 8) mac_block(ctx, buffer, data + i); if (i < data_len) { memset(buf2, 0, 8); memcpy(buf2, data + i, data_len - i); mac_block(ctx, buffer, buf2); i += 8; } if (i == 8) { memset(buf2, 0, 8); mac_block(ctx, buffer, buf2); } get_mac(buffer, mac_len, mac); return 1; } /* Compute MAC with non-zero IV. Used in some RFC 4357 algorithms */ int gost_mac_iv(gost_ctx * ctx, int mac_len, const unsigned char *iv, const unsigned char *data, unsigned int data_len, unsigned char *mac) { byte buffer[8]; byte buf2[8]; unsigned int i; memcpy(buffer, iv, 8); for (i = 0; i + 8 <= data_len; i += 8) mac_block(ctx, buffer, data + i); if (i < data_len) { memset(buf2, 0, 8); memcpy(buf2, data + i, data_len - i); mac_block(ctx, buffer, buf2); i += 8; } if (i == 8) { memset(buf2, 0, 8); mac_block(ctx, buffer, buf2); } get_mac(buffer, mac_len, mac); return 1; } /* Implements key meshing algorithm by modifing ctx and IV in place */ void cryptopro_key_meshing(gost_ctx * ctx, unsigned char *iv) { unsigned char newkey[32], newiv[8]; /* Set static keymeshing key */ /* "Decrypt" key with keymeshing key */ gost_dec(ctx, CryptoProKeyMeshingKey, newkey, 4); /* set new key */ gost_key(ctx, newkey); /* Encrypt iv with new key */ gostcrypt(ctx, iv, newiv); memcpy(iv, newiv, 8); }