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wolfcrypt/src/ge_448.c: refactor ge448_double_scalarmult_vartime() to use heap for workspace unless WOLFSSL_NO_MALLOC.

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This commit is contained in:
Daniel Pouzzner
2020-08-21 23:40:52 -05:00
parent 1735bd7430
commit 9ca94d6ca7
1 changed files with 83 additions and 26 deletions
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109
wolfcrypt/src/ge_448.c
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@ -10666,34 +10666,73 @@ static void slide(int8_t *r, const uint8_t *a)
int ge448_double_scalarmult_vartime(ge448_p2 *r, const uint8_t *a,
const ge448_p2 *p, const uint8_t *b)
{
int8_t aslide[448];
int8_t bslide[448];
ge448_p2 pi[16]; /* p,3p,..,31p */
ge448_p2 p2;
#define GE448_WINDOW_BUF_SIZE 448
int8_t *aslide = NULL;
int8_t *bslide = NULL;
ge448_p2 *pi[16]; /* p,3p,..,31p */
ge448_p2 *p2 = NULL;
int i;
int ret;
#if defined(WOLFSSL_NO_MALLOC) && !defined(XMALLOC_USER)
int8_t aslide_buf[GE448_WINDOW_BUF_SIZE];
int8_t bslide_buf[GE448_WINDOW_BUF_SIZE];
ge448_p2 pi_buf[16];
ge448_p2 p2_buf;
aslide = &aslide_buf[0];
bslide = &bslide_buf[0];
for (i = 0; i < (int)(sizeof pi / sizeof pi[0]); ++i)
pi[i] = &pi_buf[i];
p2 = &p2_buf;
#else
XMEMSET(pi, 0, sizeof pi);
aslide = (int8_t *)XMALLOC(GE448_WINDOW_BUF_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (! aslide) {
ret = MEMORY_E;
goto out;
}
bslide = (int8_t *)XMALLOC(GE448_WINDOW_BUF_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (! bslide) {
ret = MEMORY_E;
goto out;
}
for (i = 0; i < (int)(sizeof pi / sizeof pi[0]); ++i) {
pi[i] = (ge448_p2 *)XMALLOC(sizeof *pi[i], NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (! pi[i]) {
ret = MEMORY_E;
goto out;
}
}
p2 = (ge448_p2 *)XMALLOC(sizeof *p2, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (! p2) {
ret = MEMORY_E;
goto out;
}
#endif
slide(aslide, a);
slide(bslide, b);
fe448_copy(pi[0].X, p->X);
fe448_copy(pi[0].Y, p->Y);
fe448_copy(pi[0].Z, p->Z);
ge448_dbl(&p2, p);
ge448_add(&pi[1], &p2, &pi[0]);
ge448_add(&pi[2], &p2, &pi[1]);
ge448_add(&pi[3], &p2, &pi[2]);
ge448_add(&pi[4], &p2, &pi[3]);
ge448_add(&pi[5], &p2, &pi[4]);
ge448_add(&pi[6], &p2, &pi[5]);
ge448_add(&pi[7], &p2, &pi[6]);
ge448_add(&pi[8], &p2, &pi[7]);
ge448_add(&pi[9], &p2, &pi[8]);
ge448_add(&pi[10], &p2, &pi[9]);
ge448_add(&pi[11], &p2, &pi[10]);
ge448_add(&pi[12], &p2, &pi[11]);
ge448_add(&pi[13], &p2, &pi[12]);
ge448_add(&pi[14], &p2, &pi[13]);
ge448_add(&pi[15], &p2, &pi[14]);
fe448_copy(pi[0]->X, p->X);
fe448_copy(pi[0]->Y, p->Y);
fe448_copy(pi[0]->Z, p->Z);
ge448_dbl(p2, p);
ge448_add(pi[1], p2, pi[0]);
ge448_add(pi[2], p2, pi[1]);
ge448_add(pi[3], p2, pi[2]);
ge448_add(pi[4], p2, pi[3]);
ge448_add(pi[5], p2, pi[4]);
ge448_add(pi[6], p2, pi[5]);
ge448_add(pi[7], p2, pi[6]);
ge448_add(pi[8], p2, pi[7]);
ge448_add(pi[9], p2, pi[8]);
ge448_add(pi[10], p2, pi[9]);
ge448_add(pi[11], p2, pi[10]);
ge448_add(pi[12], p2, pi[11]);
ge448_add(pi[13], p2, pi[12]);
ge448_add(pi[14], p2, pi[13]);
ge448_add(pi[15], p2, pi[14]);
ge448_0(r);
@ -10708,9 +10747,9 @@ int ge448_double_scalarmult_vartime(ge448_p2 *r, const uint8_t *a,
ge448_dbl(r, r);
if (aslide[i] > 0)
ge448_add(r, r, &pi[aslide[i]/2]);
ge448_add(r, r, pi[aslide[i]/2]);
else if (aslide[i] < 0)
ge448_sub(r, r ,&pi[(-aslide[i])/2]);
ge448_sub(r, r ,pi[(-aslide[i])/2]);
if (bslide[i] > 0)
ge448_madd(r, r, &base_i[bslide[i]/2]);
@ -10718,7 +10757,25 @@ int ge448_double_scalarmult_vartime(ge448_p2 *r, const uint8_t *a,
ge448_msub(r, r, &base_i[(-bslide[i])/2]);
}
return 0;
ret = 0;
#if !defined(WOLFSSL_NO_MALLOC) || defined(XMALLOC_USER)
out:
if (aslide)
XFREE(aslide, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (bslide)
XFREE(bslide, NULL, DYNAMIC_TYPE_TMP_BUFFER);
for (i = 0; i < (int)(sizeof pi / sizeof pi[0]); ++i) {
if (pi[i])
XFREE(pi[i], NULL, DYNAMIC_TYPE_TMP_BUFFER);
}
if (p2)
XFREE(p2, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif
return ret;
#undef GE448_WINDOW_BUF_SIZE
}
/* Convert compressed point to negative of affine point.