/* Diversifies key using random UserKey Material
* Implements RFC 4357 p 6.5 key diversification algorithm
*
* inputKey - 32byte key to be diversified
* ukm - 8byte user key material
* outputKey - 32byte buffer to store diversified key
*
*/
void keyDiversifyCryptoPro(gost_ctx *ctx,const unsigned char *inputKey, const unsigned char *ukm, unsigned char *outputKey)
{
u4 k,s1,s2;
int i,j,mask;
unsigned char S[8];
memcpy(outputKey,inputKey,32);
for (i=0;i<8;i++)
{
/* Make array of integers from key */
/* Compute IV S*/
s1=0,s2=0;
for (j=0,mask=1;j<8;j++,mask<<=1)
{
k=((u4)outputKey[4*j])|(outputKey[4*j+1]<<8)|
(outputKey[4*j+2]<<16)|(outputKey[4*j+3]<<24);
if (mask & ukm[i])
{
s1+=k;
}
else
{
s2+=k;
}
}
S[0]=(unsigned char)(s1&0xff);
S[1]=(unsigned char)((s1>>8)&0xff);
S[2]=(unsigned char)((s1>>16)&0xff);
S[3]=(unsigned char)((s1>>24)&0xff);
S[4]=(unsigned char)(s2&0xff);
S[5]=(unsigned char)((s2>>8)&0xff);
S[6]=(unsigned char)((s2>>16)&0xff);
S[7]=(unsigned char)((s2>>24)&0xff);
gost_key(ctx,outputKey);
gost_enc_cfb(ctx,S,outputKey,outputKey,4);
}
}
static int dstu_cipher_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
const unsigned char *in, size_t inl)
{
size_t to_use, i, blocks;
gost_ctx *gctx = ctx->cipher_data;
unsigned char tmpiv[DSTU_CIPHER_BLOCK_SIZE], *out_start = out;
if ((!inl) && (!in))
return 0;
if ((!inl) || (!in))
return -1;
if (ctx->num) {
to_use = ((size_t)(ctx->num) < inl) ? (size_t)(ctx->num) : inl;
for (i = 0; i < to_use; i++) {
if (ctx->encrypt) {
*out = *in ^ ctx->buf[DSTU_CIPHER_BLOCK_SIZE - ctx->num + i];
ctx->iv[DSTU_CIPHER_BLOCK_SIZE - ctx->num + i] = *out;
} else {
ctx->iv[DSTU_CIPHER_BLOCK_SIZE - ctx->num + i] = *in;
*out = *in ^ ctx->buf[DSTU_CIPHER_BLOCK_SIZE - ctx->num + i];
}
in++;
out++;
}
ctx->num -= to_use;
inl -= to_use;
if (!ctx->num)
gostcrypt(gctx, ctx->iv, ctx->buf);
}
if (inl) {
blocks = inl >> 3;
if (blocks) {
if (ctx->encrypt) {
gost_enc_cfb(gctx, ctx->iv, in, out, blocks);
memcpy(ctx->iv,
out + (blocks * DSTU_CIPHER_BLOCK_SIZE) -
DSTU_CIPHER_BLOCK_SIZE, DSTU_CIPHER_BLOCK_SIZE);
} else {
memcpy(tmpiv, ctx->iv, DSTU_CIPHER_BLOCK_SIZE);
memcpy(ctx->iv,
in + (blocks * DSTU_CIPHER_BLOCK_SIZE) -
DSTU_CIPHER_BLOCK_SIZE, DSTU_CIPHER_BLOCK_SIZE);
gost_dec_cfb(gctx, tmpiv, in, out, blocks);
}
gostcrypt(gctx, ctx->iv, ctx->buf);
out += blocks * DSTU_CIPHER_BLOCK_SIZE;
in += blocks * DSTU_CIPHER_BLOCK_SIZE;
inl -= blocks * DSTU_CIPHER_BLOCK_SIZE;
}
}
if (inl) {
for (i = 0; i < inl; i++) {
if (ctx->encrypt) {
*out = *in ^ ctx->buf[i];
ctx->iv[i] = *out;
} else {
ctx->iv[i] = *in;
*out = *in ^ ctx->buf[i];
}
in++;
out++;
}
ctx->num = DSTU_CIPHER_BLOCK_SIZE - inl;
}
return out - out_start;
}
