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util: extend unbase64mem() to accept secure flag

When the flag is set, buffer is cleared on failure.
This commit is contained in:
Yu Watanabe 2019-04-08 03:41:03 +09:00
parent 03fec54396
commit 2432d09c7a
2 changed files with 56 additions and 24 deletions

View File

@ -685,11 +685,12 @@ static int unbase64_next(const char **p, size_t *l) {
return ret;
}
int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
int unbase64mem_full(const char *p, size_t l, bool secure, void **ret, size_t *ret_size) {
_cleanup_free_ uint8_t *buf = NULL;
const char *x;
uint8_t *z;
size_t len;
int r;
assert(p || l == 0);
assert(ret);
@ -712,36 +713,54 @@ int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
a = unbase64_next(&x, &l);
if (a == -EPIPE) /* End of string */
break;
if (a < 0)
return a;
if (a == INT_MAX) /* Padding is not allowed at the beginning of a 4ch block */
return -EINVAL;
if (a < 0) {
r = a;
goto on_failure;
}
if (a == INT_MAX) { /* Padding is not allowed at the beginning of a 4ch block */
r = -EINVAL;
goto on_failure;
}
b = unbase64_next(&x, &l);
if (b < 0)
return b;
if (b == INT_MAX) /* Padding is not allowed at the second character of a 4ch block either */
return -EINVAL;
if (b < 0) {
r = b;
goto on_failure;
}
if (b == INT_MAX) { /* Padding is not allowed at the second character of a 4ch block either */
r = -EINVAL;
goto on_failure;
}
c = unbase64_next(&x, &l);
if (c < 0)
return c;
if (c < 0) {
r = c;
goto on_failure;
}
d = unbase64_next(&x, &l);
if (d < 0)
return d;
if (d < 0) {
r = d;
goto on_failure;
}
if (c == INT_MAX) { /* Padding at the third character */
if (d != INT_MAX) /* If the third character is padding, the fourth must be too */
return -EINVAL;
if (d != INT_MAX) { /* If the third character is padding, the fourth must be too */
r = -EINVAL;
goto on_failure;
}
/* b == 00YY0000 */
if (b & 15)
return -EINVAL;
if (b & 15) {
r = -EINVAL;
goto on_failure;
}
if (l > 0) /* Trailing rubbish? */
return -ENAMETOOLONG;
if (l > 0) { /* Trailing rubbish? */
r = -ENAMETOOLONG;
goto on_failure;
}
*(z++) = (uint8_t) a << 2 | (uint8_t) (b >> 4); /* XXXXXXYY */
break;
@ -749,11 +768,15 @@ int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
if (d == INT_MAX) {
/* c == 00ZZZZ00 */
if (c & 3)
return -EINVAL;
if (c & 3) {
r = -EINVAL;
goto on_failure;
}
if (l > 0) /* Trailing rubbish? */
return -ENAMETOOLONG;
if (l > 0) { /* Trailing rubbish? */
r = -ENAMETOOLONG;
goto on_failure;
}
*(z++) = (uint8_t) a << 2 | (uint8_t) b >> 4; /* XXXXXXYY */
*(z++) = (uint8_t) b << 4 | (uint8_t) c >> 2; /* YYYYZZZZ */
@ -771,6 +794,12 @@ int unbase64mem(const char *p, size_t l, void **ret, size_t *ret_size) {
*ret = TAKE_PTR(buf);
return 0;
on_failure:
if (secure)
explicit_bzero_safe(buf, len);
return r;
}
void hexdump(FILE *f, const void *p, size_t s) {

View File

@ -33,6 +33,9 @@ ssize_t base64mem(const void *p, size_t l, char **out);
int base64_append(char **prefix, int plen,
const void *p, size_t l,
int margin, int width);
int unbase64mem(const char *p, size_t l, void **mem, size_t *len);
int unbase64mem_full(const char *p, size_t l, bool secure, void **mem, size_t *len);
static inline int unbase64mem(const char *p, size_t l, void **mem, size_t *len) {
return unbase64mem_full(p, l, false, mem, len);
}
void hexdump(FILE *f, const void *p, size_t s);