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/*
version 20140420
D. J. Bernstein
Public domain.
*/
#include <stdint.h>
#include "crypto_core_salsa20.h"
#include "crypto_stream_salsa20.h"
#include "utils.h"
#include "../stream_salsa20.h"
#include "salsa20_ref.h"
#ifndef HAVE_AMD64_ASM
static int
stream_ref(unsigned char *c, unsigned long long clen, const unsigned char *n,
const unsigned char *k)
{
unsigned char in[16];
unsigned char block[64];
unsigned char kcopy[32];
unsigned int i;
unsigned int u;
if (!clen) {
return 0;
}
for (i = 0; i < 32; i++) {
kcopy[i] = k[i];
}
for (i = 0; i < 8; i++) {
in[i] = n[i];
}
for (i = 8; i < 16; i++) {
in[i] = 0;
}
while (clen >= 64) {
crypto_core_salsa20(c, in, kcopy, NULL);
u = 1;
for (i = 8; i < 16; i++) {
u += (unsigned int) in[i];
in[i] = u;
u >>= 8;
}
clen -= 64;
c += 64;
}
if (clen) {
crypto_core_salsa20(block, in, kcopy, NULL);
for (i = 0; i < (unsigned int) clen; i++) {
c[i] = block[i];
}
}
sodium_memzero(block, sizeof block);
sodium_memzero(kcopy, sizeof kcopy);
return 0;
}
static int
stream_ref_xor_ic(unsigned char *c, const unsigned char *m,
unsigned long long mlen, const unsigned char *n, uint64_t ic,
const unsigned char *k)
{
unsigned char in[16];
unsigned char block[64];
unsigned char kcopy[32];
unsigned int i;
unsigned int u;
if (!mlen) {
return 0;
}
for (i = 0; i < 32; i++) {
kcopy[i] = k[i];
}
for (i = 0; i < 8; i++) {
in[i] = n[i];
}
for (i = 8; i < 16; i++) {
in[i] = (unsigned char) (ic & 0xff);
ic >>= 8;
}
while (mlen >= 64) {
crypto_core_salsa20(block, in, kcopy, NULL);
for (i = 0; i < 64; i++) {
c[i] = m[i] ^ block[i];
}
u = 1;
for (i = 8; i < 16; i++) {
u += (unsigned int) in[i];
in[i] = u;
u >>= 8;
}
mlen -= 64;
c += 64;
m += 64;
}
if (mlen) {
crypto_core_salsa20(block, in, kcopy, NULL);
for (i = 0; i < (unsigned int) mlen; i++) {
c[i] = m[i] ^ block[i];
}
}
sodium_memzero(block, sizeof block);
sodium_memzero(kcopy, sizeof kcopy);
return 0;
}
struct crypto_stream_salsa20_implementation
crypto_stream_salsa20_ref_implementation = {
SODIUM_C99(.stream =) stream_ref,
SODIUM_C99(.stream_xor_ic =) stream_ref_xor_ic,
};
#endif
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