/**
Add entropy to the PRNG state
@param in The data to add
@param inlen Length of the data to add
@param prng PRNG state to update
@return CRYPT_OK if successful
*/
int sober128_add_entropy(const unsigned char *in, unsigned long inlen, prng_state *prng)
{
struct sober128_prng *c;
ulong32 i, k;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(prng != NULL);
c = &(prng->sober128);
if (c->flag == 1) {
/* this is the first call to the add_entropy so this input is the key */
/* inlen must be multiple of 4 bytes */
if ((inlen & 3) != 0) {
return CRYPT_INVALID_KEYSIZE;
}
for (i = 0; i < inlen; i += 4) {
k = BYTE2WORD((unsigned char *)&in[i]);
ADDKEY(k);
cycle(c->R);
XORNL(nltap(c));
}
/* also fold in the length of the key */
ADDKEY(inlen);
/* now diffuse */
s128_diffuse(c);
s128_genkonst(c);
s128_savestate(c);
c->nbuf = 0;
c->flag = 0;
c->set = 1;
} else {
/* ok we are adding an IV then... */
s128_reloadstate(c);
/* inlen must be multiple of 4 bytes */
if ((inlen & 3) != 0) {
return CRYPT_INVALID_KEYSIZE;
}
for (i = 0; i < inlen; i += 4) {
k = BYTE2WORD((unsigned char *)&in[i]);
ADDKEY(k);
cycle(c->R);
XORNL(nltap(c));
}
/* also fold in the length of the key */
ADDKEY(inlen);
/* now diffuse */
s128_diffuse(c);
c->nbuf = 0;
}
return CRYPT_OK;
}
/**
Set IV to the Sober128 state
@param c The Sober12820 state
@param iv The IV data to add
@param ivlen The length of the IV (must be 12)
@return CRYPT_OK on success
*/
int sober128_stream_setiv(sober128_state *c, const unsigned char *iv, unsigned long ivlen)
{
ulong32 i, k;
LTC_ARGCHK(c != NULL);
LTC_ARGCHK(iv != NULL);
LTC_ARGCHK(ivlen > 0);
/* ok we are adding an IV then... */
s128_reloadstate(c);
/* ivlen must be multiple of 4 bytes */
if ((ivlen & 3) != 0) {
return CRYPT_INVALID_KEYSIZE;
}
for (i = 0; i < ivlen; i += 4) {
k = BYTE2WORD((unsigned char *)&iv[i]);
ADDKEY(k);
cycle(c->R);
XORNL(nltap(c));
}
/* also fold in the length of the key */
ADDKEY(ivlen);
/* now diffuse */
s128_diffuse(c);
c->nbuf = 0;
return CRYPT_OK;
}
int sober128_add_entropy(const unsigned char *buf, unsigned long len, prng_state *prng)
{
struct sober128_prng *c;
ulong32 i, k;
c = &(prng->sober128);
if (c->flag == 1) {
/* this is the first call to the add_entropy so this input is the key */
/* len must be multiple of 4 bytes */
assert ((len & 3) == 0);
for (i = 0; i < len; i += 4) {
k = BYTE2WORD(&buf[i]);
ADDKEY(k);
cycle(c->R);
XORNL(nltap(c));
}
/* also fold in the length of the key */
ADDKEY(len);
/* now diffuse */
s128_diffuse(c);
s128_genkonst(c);
s128_savestate(c);
c->nbuf = 0;
c->flag = 0;
c->set = 1;
} else {
/* ok we are adding an IV then... */
s128_reloadstate(c);
/* len must be multiple of 4 bytes */
assert ((len & 3) == 0);
for (i = 0; i < len; i += 4) {
k = BYTE2WORD(&buf[i]);
ADDKEY(k);
cycle(c->R);
XORNL(nltap(c));
}
/* also fold in the length of the key */
ADDKEY(len);
/* now diffuse */
s128_diffuse(c);
c->nbuf = 0;
}
return CRYPT_OK;
}
/* Published "IV" interface
*/
void
s128_IV(s128_ctx *c, UCHAR iv[], int ivlen)
{
s128_reloadstate(c);
s128_loadkey(c, iv, ivlen);
}
