cryb.to/cryb-to
1
0
Fork 0
mirror of https://github.com/cryb-to/cryb-to.git synced 2024-12-22 12:31:07 +00:00
Code Issues Projects Releases Packages Wiki Activity

In mpi_load(), use be32dec() when possible.

Browse source 
In mpi_set(), it is impossible for the value being loaded to exceed
the minimum size of an mpi; thus, there is no need for mpi_grow().
This commit is contained in:
Dag-Erling Smørgrav 2014-12-29 15:08:09 +00:00 committed by des
parent 7a09b0638f
commit 82f5c5cf77
1 changed files with 4 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
lib/mpi/mpi.c
View file

@ -34,6 +34,7 @@
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
#include <cryb/endian.h>
#include <cryb/mpi.h> #include <cryb/mpi.h>
/* n rounded up to nearest multiple of p */ /* n rounded up to nearest multiple of p */
@ -180,11 +181,7 @@ mpi_load(cryb_mpi *X, const uint8_t *a, size_t len)
return (-1); return (-1);
/* load whole words */ /* load whole words */
for (i = 0; len >= 4; ++i, len -= 4) for (i = 0; len >= 4; ++i, len -= 4)
X->words[i] = X->words[i] = be32dec(&a[len - 4]);
a[len - 4] << 24 |
a[len - 3] << 16 |
a[len - 2] << 8 |
a[len - 1];
/* load remaining bytes */ /* load remaining bytes */
switch (len) { switch (len) {
case 3: case 3:
@ -200,6 +197,7 @@ mpi_load(cryb_mpi *X, const uint8_t *a, size_t len)
} }
/* i now points to the msw */ /* i now points to the msw */
/* compute msb of msw */ /* compute msb of msw */
/* XXX use flsl() */
for (X->msb = 31; X->msb > 0; --X->msb) for (X->msb = 31; X->msb > 0; --X->msb)
if (X->words[i] & (1 << X->msb)) if (X->words[i] & (1 << X->msb))
break; break;
@ -217,8 +215,6 @@ mpi_set(cryb_mpi *X, int32_t z)
uint32_t zabs; uint32_t zabs;
mpi_zero(X); mpi_zero(X);
if (mpi_grow(X, sizeof z * 8) != 0)
return (-1);
if (z < 0) { if (z < 0) {
X->neg = 1; X->neg = 1;
zabs = -z; zabs = -z;
@ -226,6 +222,7 @@ mpi_set(cryb_mpi *X, int32_t z)
zabs = z; zabs = z;
} }
X->words[0] = zabs; X->words[0] = zabs;
/* XXX use flsl() */
while (zabs > 0) { while (zabs > 0) {
X->msb++; X->msb++;
zabs >>= 1; zabs >>= 1;