diff options
Diffstat (limited to 'ks_mmap.c')
| -rw-r--r-- | ks_mmap.c | 42 |
1 files changed, 39 insertions, 3 deletions
@@ -51,7 +51,15 @@ #define MAP_FILE 0 #endif +/* + * Storing the KEK in with the keys it's protecting is a bad idea, but we have no better + * place to put it (real protection requires dedicated hardware, which we don't have here). + */ + +#define KEKBUF_LEN (bitsToBytes(256)) + static hal_ks_keydb_t *db; +static uint8_t *kekbuf; const hal_ks_keydb_t *hal_ks_get_keydb(void) { @@ -62,7 +70,7 @@ const hal_ks_keydb_t *hal_ks_get_keydb(void) const char * const home = getenv("HOME"); const char * const base = HAL_KS_MMAP_FILE; const long pagemask = sysconf(_SC_PAGESIZE) - 1; - const size_t len = (sizeof(hal_ks_keydb_t) + pagemask) & ~pagemask; + const size_t len = (sizeof(hal_ks_keydb_t) + KEKBUF_LEN + pagemask) & ~pagemask; char fn_[strlen(base) + (home == NULL ? 0 : strlen(home)) + 2]; const char *fn = fn_; @@ -87,8 +95,8 @@ const hal_ks_keydb_t *hal_ks_get_keydb(void) fd = open(fn, O_RDWR | O_CREAT, 0600); } - if (fd >= 0) - db = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd, 0); + if (fd >= 0 && (db = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, fd, 0)) != NULL) + kekbuf = (uint8_t *) (db + 1); (void) close(fd); @@ -135,6 +143,34 @@ hal_error_t hal_ks_set_pin(const hal_user_t user, return HAL_OK; } +hal_error_t hal_ks_get_kek(uint8_t *kek, + size_t *kek_len, + const size_t kek_max) +{ + if (kek == NULL || kek_len == NULL || kek_max < bitsToBytes(128)) + return HAL_ERROR_BAD_ARGUMENTS; + + if (kekbuf == NULL) + return HAL_ERROR_IMPOSSIBLE; + + hal_error_t err; + + const size_t len = ((kek_max < bitsToBytes(192)) ? bitsToBytes(128) : + (kek_max < bitsToBytes(256)) ? bitsToBytes(192) : + bitsToBytes(256)); + + uint8_t t = 0; + + for (int i = 0; i < KEKBUF_LEN; i++) + t |= kekbuf[i]; + + if (t == 0 && (err = hal_rpc_get_random(kekbuf, sizeof(KEKBUF_LEN))) != HAL_OK) + return err; + + memcpy(kek, kekbuf, len); + return HAL_OK; +} + /* * Local variables: * indent-tabs-mode: nil |