Lennart Poettering
cbae575e0f
This adds to new helpers: keyring_read() for reading a key data from a keyring entry, and TAKE_KEY_SERIAL which is what TAKE_FD is for fds, but for key_serial_t. The former is immediately used by ask-password-api.c
39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
#include "keyring-util.h"
|
|
#include "memory-util.h"
|
|
#include "missing_syscall.h"
|
|
|
|
int keyring_read(key_serial_t serial, void **ret, size_t *ret_size) {
|
|
size_t m = 100;
|
|
|
|
for (;;) {
|
|
_cleanup_(erase_and_freep) uint8_t *p = NULL;
|
|
long n;
|
|
|
|
p = new(uint8_t, m+1);
|
|
if (!p)
|
|
return -ENOMEM;
|
|
|
|
n = keyctl(KEYCTL_READ, (unsigned long) serial, (unsigned long) p, (unsigned long) m, 0);
|
|
if (n < 0)
|
|
return -errno;
|
|
|
|
if ((size_t) n <= m) {
|
|
p[n] = 0; /* NUL terminate, just in case */
|
|
|
|
if (ret)
|
|
*ret = TAKE_PTR(p);
|
|
if (ret_size)
|
|
*ret_size = n;
|
|
|
|
return 0;
|
|
}
|
|
|
|
if (m > (SIZE_MAX-1) / 2) /* overflow check */
|
|
return -ENOMEM;
|
|
|
|
m *= 2;
|
|
}
|
|
}
|