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#include <assert.h>
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "core.h"
#include "crypto_core_hchacha20.h"
#include "crypto_onetimeauth_poly1305.h"
#include "crypto_secretbox_xchacha20poly1305.h"
#include "crypto_stream_chacha20.h"
#include "private/common.h"
#include "utils.h"
#define crypto_secretbox_xchacha20poly1305_ZEROBYTES 32U
int
crypto_secretbox_xchacha20poly1305_detached(unsigned char *c,
unsigned char *mac,
const unsigned char *m,
unsigned long long mlen,
const unsigned char *n,
const unsigned char *k)
{
crypto_onetimeauth_poly1305_state state;
unsigned char block0[64U];
unsigned char subkey[crypto_stream_chacha20_KEYBYTES];
unsigned long long i;
unsigned long long mlen0;
crypto_core_hchacha20(subkey, n, k, NULL);
if (((uintptr_t) c > (uintptr_t) m &&
(uintptr_t) c - (uintptr_t) m < mlen) ||
((uintptr_t) m > (uintptr_t) c &&
(uintptr_t) m - (uintptr_t) c < mlen)) { /* LCOV_EXCL_LINE */
memmove(c, m, mlen);
m = c;
}
memset(block0, 0U, crypto_secretbox_xchacha20poly1305_ZEROBYTES);
COMPILER_ASSERT(64U >= crypto_secretbox_xchacha20poly1305_ZEROBYTES);
mlen0 = mlen;
if (mlen0 > 64U - crypto_secretbox_xchacha20poly1305_ZEROBYTES) {
mlen0 = 64U - crypto_secretbox_xchacha20poly1305_ZEROBYTES;
}
for (i = 0U; i < mlen0; i++) {
block0[i + crypto_secretbox_xchacha20poly1305_ZEROBYTES] = m[i];
}
crypto_stream_chacha20_xor(block0, block0,
mlen0 + crypto_secretbox_xchacha20poly1305_ZEROBYTES,
n + 16, subkey);
COMPILER_ASSERT(crypto_secretbox_xchacha20poly1305_ZEROBYTES >=
crypto_onetimeauth_poly1305_KEYBYTES);
crypto_onetimeauth_poly1305_init(&state, block0);
for (i = 0U; i < mlen0; i++) {
c[i] = block0[crypto_secretbox_xchacha20poly1305_ZEROBYTES + i];
}
sodium_memzero(block0, sizeof block0);
if (mlen > mlen0) {
crypto_stream_chacha20_xor_ic(c + mlen0, m + mlen0, mlen - mlen0,
n + 16, 1U, subkey);
}
sodium_memzero(subkey, sizeof subkey);
crypto_onetimeauth_poly1305_update(&state, c, mlen);
crypto_onetimeauth_poly1305_final(&state, mac);
sodium_memzero(&state, sizeof state);
return 0;
}
int
crypto_secretbox_xchacha20poly1305_easy(unsigned char *c,
const unsigned char *m,
unsigned long long mlen,
const unsigned char *n,
const unsigned char *k)
{
if (mlen > crypto_secretbox_xchacha20poly1305_MESSAGEBYTES_MAX) {
sodium_misuse();
}
return crypto_secretbox_xchacha20poly1305_detached
(c + crypto_secretbox_xchacha20poly1305_MACBYTES, c, m, mlen, n, k);
}
int
crypto_secretbox_xchacha20poly1305_open_detached(unsigned char *m,
const unsigned char *c,
const unsigned char *mac,
unsigned long long clen,
const unsigned char *n,
const unsigned char *k)
{
unsigned char block0[64U];
unsigned char subkey[crypto_stream_chacha20_KEYBYTES];
unsigned long long i;
unsigned long long mlen0;
crypto_core_hchacha20(subkey, n, k, NULL);
crypto_stream_chacha20(block0, crypto_stream_chacha20_KEYBYTES,
n + 16, subkey);
if (crypto_onetimeauth_poly1305_verify(mac, c, clen, block0) != 0) {
sodium_memzero(subkey, sizeof subkey);
return -1;
}
if (m == NULL) {
return 0;
}
if (((uintptr_t) c >= (uintptr_t) m &&
(uintptr_t) c - (uintptr_t) m < clen) ||
((uintptr_t) m >= (uintptr_t) c &&
(uintptr_t) m - (uintptr_t) c < clen)) { /* LCOV_EXCL_LINE */
memmove(m, c, clen);
c = m;
}
mlen0 = clen;
if (mlen0 > 64U - crypto_secretbox_xchacha20poly1305_ZEROBYTES) {
mlen0 = 64U - crypto_secretbox_xchacha20poly1305_ZEROBYTES;
}
for (i = 0U; i < mlen0; i++) {
block0[crypto_secretbox_xchacha20poly1305_ZEROBYTES + i] = c[i];
}
crypto_stream_chacha20_xor(block0, block0,
crypto_secretbox_xchacha20poly1305_ZEROBYTES + mlen0,
n + 16, subkey);
for (i = 0U; i < mlen0; i++) {
m[i] = block0[i + crypto_secretbox_xchacha20poly1305_ZEROBYTES];
}
if (clen > mlen0) {
crypto_stream_chacha20_xor_ic(m + mlen0, c + mlen0, clen - mlen0,
n + 16, 1U, subkey);
}
sodium_memzero(subkey, sizeof subkey);
return 0;
}
int
crypto_secretbox_xchacha20poly1305_open_easy(unsigned char *m,
const unsigned char *c,
unsigned long long clen,
const unsigned char *n,
const unsigned char *k)
{
if (clen < crypto_secretbox_xchacha20poly1305_MACBYTES) {
return -1;
}
return crypto_secretbox_xchacha20poly1305_open_detached
(m, c + crypto_secretbox_xchacha20poly1305_MACBYTES, c,
clen - crypto_secretbox_xchacha20poly1305_MACBYTES, n, k);
}
size_t
crypto_secretbox_xchacha20poly1305_keybytes(void)
{
return crypto_secretbox_xchacha20poly1305_KEYBYTES;
}
size_t
crypto_secretbox_xchacha20poly1305_noncebytes(void)
{
return crypto_secretbox_xchacha20poly1305_NONCEBYTES;
}
size_t
crypto_secretbox_xchacha20poly1305_macbytes(void)
{
return crypto_secretbox_xchacha20poly1305_MACBYTES;
}
size_t
crypto_secretbox_xchacha20poly1305_messagebytes_max(void)
{
return crypto_secretbox_xchacha20poly1305_MESSAGEBYTES_MAX;
}
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