quakequest/Projects/Android/jni/darkplaces/hmac.c
2021-02-02 22:53:37 +00:00

61 lines
1.2 KiB
C

#include "quakedef.h"
#include "hmac.h"
qboolean hmac(
hashfunc_t hfunc, int hlen, int hblock,
unsigned char *out,
const unsigned char *in, int n,
const unsigned char *key, int k
)
{
unsigned char hashbuf[32];
unsigned char k_xor_ipad[128];
unsigned char k_xor_opad[128];
unsigned char *catbuf;
int i;
if(sizeof(hashbuf) < (size_t) hlen)
return false;
if(sizeof(k_xor_ipad) < (size_t) hblock)
return false;
if(sizeof(k_xor_ipad) < (size_t) hlen)
return false;
catbuf = (unsigned char *)Mem_Alloc(tempmempool, (size_t) hblock + max((size_t) hlen, (size_t) n));
if(k > hblock)
{
// hash the key if it is too long
hfunc(k_xor_opad, key, k);
key = k_xor_opad;
k = hlen;
}
if(k < hblock)
{
// zero pad the key if it is too short
if(key != k_xor_opad)
memcpy(k_xor_opad, key, k);
for(i = k; i < hblock; ++i)
k_xor_opad[i] = 0;
key = k_xor_opad;
k = hblock;
}
for(i = 0; i < hblock; ++i)
{
k_xor_ipad[i] = key[i] ^ 0x36;
k_xor_opad[i] = key[i] ^ 0x5c;
}
memcpy(catbuf, k_xor_ipad, hblock);
memcpy(catbuf + hblock, in, n);
hfunc(hashbuf, catbuf, hblock + n);
memcpy(catbuf, k_xor_opad, hblock);
memcpy(catbuf + hblock, hashbuf, hlen);
hfunc(out, catbuf, hblock + hlen);
Mem_Free(catbuf);
return true;
}