Merge pull request #12965 from keszybz/auto-erase

_cleanup_(erase_and_freep)

src/network/netdev/macsec.c

@@ -718,7 +718,7 @@ int config_parse_macsec_key(
 
         _cleanup_(macsec_transmit_association_free_or_set_invalidp) TransmitAssociation *a = NULL;
         _cleanup_(macsec_receive_association_free_or_set_invalidp) ReceiveAssociation *b = NULL;
-        _cleanup_free_ void *p;
+        _cleanup_(erase_and_freep) void *p = NULL;
         MACsec *s = userdata;
         SecurityAssociation *dest;
         size_t l;
@@ -743,18 +743,17 @@ int config_parse_macsec_key(
 
         r = unhexmem_full(rvalue, strlen(rvalue), true, &p, &l);
         if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r,
-                           "Failed to parse key. Ignoring assignment: %m");
-                return 0;
-        }
-        if (l != 16) {
-                /* See DEFAULT_SAK_LEN in drivers/net/macsec.c */
-                explicit_bzero_safe(p, l);
-                log_syntax(unit, LOG_ERR, filename, line, 0,
-                           "Invalid key length (%zu). Ignoring assignment", l);
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse key. Ignoring assignment: %m");
                 return 0;
         }
 
+        if (l != 16) {
+                /* See DEFAULT_SAK_LEN in drivers/net/macsec.c */
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Invalid key length (%zu). Ignoring assignment", l);
+                return 0;
+        }
+
+        explicit_bzero_safe(dest->key, dest->key_len);
         free_and_replace(dest->key, p);
         dest->key_len = l;
 
@@ -972,7 +971,7 @@ int config_parse_macsec_use_for_encoding(
 }
 
 static int macsec_read_key_file(NetDev *netdev, SecurityAssociation *sa) {
-        _cleanup_free_ uint8_t *key = NULL;
+        _cleanup_(erase_and_freep) uint8_t *key = NULL;
         size_t key_len;
         int r;
 
@@ -987,12 +986,10 @@ static int macsec_read_key_file(NetDev *netdev, SecurityAssociation *sa) {
                 return log_netdev_error_errno(netdev, r,
                                               "Failed to read key from '%s', ignoring: %m",
                                               sa->key_file);
-        if (key_len != 16) {
-                explicit_bzero_safe(key, key_len);
+
+        if (key_len != 16)
                 return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),
-                                              "Invalid key length (%zu bytes), ignoring: %m",
-                                              key_len);
-        }
+                                              "Invalid key length (%zu bytes), ignoring: %m", key_len);
 
         explicit_bzero_safe(sa->key, sa->key_len);
         free_and_replace(sa->key, key);

src/network/netdev/wireguard.c

@@ -480,7 +480,7 @@ static int wireguard_decode_key_and_warn(
                 unsigned line,
                 const char *lvalue) {
 
-        _cleanup_free_ void *key = NULL;
+        _cleanup_(erase_and_freep) void *key = NULL;
         size_t len;
         int r;
 
@@ -501,12 +501,10 @@ static int wireguard_decode_key_and_warn(
         if (r < 0)
                 return log_syntax(unit, LOG_ERR, filename, line, r,
                            "Failed to decode wireguard key provided by %s=, ignoring assignment: %m", lvalue);
-        if (len != WG_KEY_LEN) {
-                explicit_bzero_safe(key, len);
+        if (len != WG_KEY_LEN)
                 return log_syntax(unit, LOG_ERR, filename, line, 0,
                            "Wireguard key provided by %s= has invalid length (%zu bytes), ignoring assignment.",
                            lvalue, len);
-        }
 
         memcpy(ret, key, WG_KEY_LEN);
         return 0;
@@ -894,7 +892,7 @@ static void wireguard_done(NetDev *netdev) {
 }
 
 static int wireguard_read_key_file(const char *filename, uint8_t dest[static WG_KEY_LEN]) {
-        _cleanup_free_ char *key = NULL;
+        _cleanup_(erase_and_freep) char *key = NULL;
         size_t key_len;
         int r;
 
@@ -905,17 +903,11 @@ static int wireguard_read_key_file(const char *filename, uint8_t dest[static WG_
         if (r < 0)
                 return r;
 
-        if (key_len != WG_KEY_LEN) {
-                r = -EINVAL;
-                goto finalize;
-        }
+        if (key_len != WG_KEY_LEN)
+                return -EINVAL;
 
         memcpy(dest, key, WG_KEY_LEN);
-        r = 0;
-
-finalize:
-        explicit_bzero_safe(key, key_len);
-        return r;
+        return 0;
 }
 
 static int wireguard_peer_verify(WireguardPeer *peer) {