| /********************************************************************** |
| * 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 <string.h> |
| #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); |
| } |