mirror of
https://github.com/oxen-io/session-android.git
synced 2024-12-24 16:57:50 +00:00
48 lines
1.1 KiB
C
48 lines
1.1 KiB
C
#include <string.h>
|
|
#include "crypto_sign.h"
|
|
#include "crypto_hash_sha512.h"
|
|
#include "ge.h"
|
|
#include "sc.h"
|
|
#include "zeroize.h"
|
|
|
|
/* NEW: Compare to pristine crypto_sign()
|
|
Uses explicit private key for nonce derivation and as scalar,
|
|
instead of deriving both from a master key.
|
|
*/
|
|
int crypto_sign_modified(
|
|
unsigned char *sm,
|
|
const unsigned char *m,unsigned long long mlen,
|
|
const unsigned char *sk, const unsigned char* pk,
|
|
const unsigned char* random
|
|
)
|
|
{
|
|
unsigned char nonce[64];
|
|
unsigned char hram[64];
|
|
ge_p3 R;
|
|
int count=0;
|
|
|
|
memmove(sm + 64,m,mlen);
|
|
memmove(sm + 32,sk,32); /* NEW: Use privkey directly for nonce derivation */
|
|
|
|
/* NEW : add prefix to separate hash uses - see .h */
|
|
sm[0] = 0xFE;
|
|
for (count = 1; count < 32; count++)
|
|
sm[count] = 0xFF;
|
|
|
|
/* NEW: add suffix of random data */
|
|
memmove(sm + mlen + 64, random, 64);
|
|
|
|
crypto_hash_sha512(nonce,sm,mlen + 128);
|
|
memmove(sm + 32,pk,32);
|
|
|
|
sc_reduce(nonce);
|
|
ge_scalarmult_base(&R,nonce);
|
|
ge_p3_tobytes(sm,&R);
|
|
|
|
crypto_hash_sha512(hram,sm,mlen + 64);
|
|
sc_reduce(hram);
|
|
sc_muladd(sm + 32,hram,sk,nonce); /* NEW: Use privkey directly */
|
|
|
|
return 0;
|
|
}
|