static int
salsa208poly1305_encrypt(uint8_t *c, const uint8_t *m, const uint32_t mlen,
const uint8_t *n, const uint8_t *k) {
uint8_t c*k[COKB];
crypto_stream_salsa208(c*k, COKB, n, k);
crypto_stream_salsa208_xor(c + COB, m, mlen, n, k);
crypto_onetimeauth_poly1305(c, c + COB, mlen, c*k);
return 0;
}
int crypto_secretbox_salsa208poly1305(
unsigned char *c,
const unsigned char *m,unsigned long long mlen,
const unsigned char *n,
const unsigned char *k
)
{
int i;
if (mlen < 32) return -1;
crypto_stream_salsa208_xor(c,m,mlen,n,k);
crypto_onetimeauth_poly1305(c + 16,c + 32,mlen - 32,c);
for (i = 0;i < 16;++i) c[i] = 0;
return 0;
}
int crypto_secretbox_salsa208poly1305_open(
unsigned char *m,
const unsigned char *c,unsigned long long clen,
const unsigned char *n,
const unsigned char *k
)
{
int i;
unsigned char subkey[32];
if (clen < 32) return -1;
crypto_stream_salsa208(subkey,32,n,k);
if (crypto_onetimeauth_poly1305_verify(c + 16,c + 32,clen - 32,subkey) != 0) return -1;
crypto_stream_salsa208_xor(m,c,clen,n,k);
for (i = 0;i < 32;++i) m[i] = 0;
return 0;
}
static int
salsa208poly1305_decrypt(uint8_t *m, const uint8_t *c, const uint32_t clen,
const uint8_t *n, const uint8_t *k) {
uint8_t c*k[COKB];
if (clen < COB) {
return -1;
}
int mlen = clen - COB;
crypto_stream_salsa208(c*k, COKB, n, k);
if (crypto_onetimeauth_poly1305_verify(c, c + COB, mlen, c*k) == 0) {
return crypto_stream_salsa208_xor(m, c + COB, mlen, n, k);
}
return -1;
}
