WolfSSL
/
wolfssl
mirror of https://github.com/wolfSSL/wolfssl.git
1
0
Fork 0
Code Issues Releases Wiki Activity

Merge pull request #3700 from SparkiDev/sp_math_lshb 

SP math lshb: check space for result
pull/3703/head
toddouska 2021-02-10 16:01:27 -08:00 committed by GitHub
parent 67b1280bbf ca3c5bf6c4
commit 6983aa9331
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 36 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
wolfcrypt/src/sp_int.c
View File

@ -4168,35 +4168,42 @@ int sp_lshd(sp_int* a, int s)
*/
static int sp_lshb(sp_int* a, int n)
{
int err = MP_OKAY;
if (a->used != 0) {
int s = n >> SP_WORD_SHIFT;
int i;
n &= SP_WORD_MASK;
if (n != 0) {
sp_int_digit v;
if (a->used + s >= a->size) {
err = MP_VAL;
}
if (err == MP_OKAY) {
n &= SP_WORD_MASK;
if (n != 0) {
sp_int_digit v;
v = a->dp[a->used - 1] >> (SP_WORD_SIZE - n);
a->dp[a->used - 1 + s] = a->dp[a->used - 1] << n;
for (i = a->used - 2; i >= 0; i--) {
a->dp[i + 1 + s] |= a->dp[i] >> (SP_WORD_SIZE - n);
a->dp[i + s] = a->dp[i] << n;
v = a->dp[a->used - 1] >> (SP_WORD_SIZE - n);
a->dp[a->used - 1 + s] = a->dp[a->used - 1] << n;
for (i = a->used - 2; i >= 0; i--) {
a->dp[i + 1 + s] |= a->dp[i] >> (SP_WORD_SIZE - n);
a->dp[i + s] = a->dp[i] << n;
}
if (v != 0) {
a->dp[a->used + s] = v;
a->used++;
}
}
if (v != 0) {
a->dp[a->used + s] = v;
a->used++;
else if (s > 0) {
for (i = a->used - 1; i >= 0; i--) {
a->dp[i + s] = a->dp[i];
}
}
a->used += s;
XMEMSET(a->dp, 0, SP_WORD_SIZEOF * s);
}
else if (s > 0) {
for (i = a->used - 1; i >= 0; i--) {
a->dp[i + s] = a->dp[i];
}
}
a->used += s;
XMEMSET(a->dp, 0, SP_WORD_SIZEOF * s);
}
return MP_OKAY;
return err;
}
#endif /* WOLFSSL_SP_MATH_ALL || !NO_DH || HAVE_ECC ||
* (!NO_RSA && !WOLFSSL_RSA_VERIFY_ONLY) */
@ -4299,14 +4306,14 @@ int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
int ret;
int done = 0;
int i;
int s;
int s = 0;
sp_int_digit dt;
sp_int_digit t;
#ifdef WOLFSSL_SMALL_STACK
sp_int* sa = NULL;
sp_int* sd;
sp_int* tr;
sp_int* trial;
sp_int* sd = NULL;
sp_int* tr = NULL;
sp_int* trial = NULL;
#else
sp_int sa[1];
sp_int sd[1];
@ -4405,10 +4412,12 @@ int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
s = SP_WORD_SIZE - (s & SP_WORD_MASK);
sp_copy(a, sa);
if (s != SP_WORD_SIZE) {
sp_lshb(sa, s);
sp_copy(d, sd);
sp_lshb(sd, s);
d = sd;
err = sp_lshb(sa, s);
if (err == MP_OKAY) {
sp_copy(d, sd);
d = sd;
err = sp_lshb(sd, s);
}
}
}
if ((!done) && (err == MP_OKAY) && (d->used > 0)) {