core: refuse credentials with invalid names matching with glob

Even if the glob pattern is valid, the pattern may match credentials
with invalid names. So, we need to check the names of the found
credentials.

Follow-up for 947c4d3952.

src/core/exec-credential.c

@@ -502,6 +502,11 @@ static int load_credential_glob(
                                 free_and_replace(fn, renamed);
                         }
 
+                        if (!credential_name_valid(fn)) {
+                                log_debug("Skipping credential with invalid name: %s", fn);
+                                continue;
+                        }
+
                         if (faccessat(write_dfd, fn, F_OK, AT_SYMLINK_NOFOLLOW) >= 0) {
                                 log_debug("Skipping credential with duplicated ID %s at %s", fn, *p);
                                 continue;

test/units/TEST-54-CREDS.sh

@@ -279,6 +279,24 @@ echo -n ignored >/run/credstore/test.creds.second
 mkdir -p /etc/credstore
 echo -n b >/etc/credstore/test.creds.second
 echo -n c >/etc/credstore/test.creds.third
+# Credential name cannot contain ':'
+echo -n hoge >/etc/credstore/test.creds.hoge:invalid
+
+# Check if credentials with invalid names are not imported.
+systemd-run -p "ImportCredential=test.creds.*" \
+            --unit=test-54-ImportCredential.service \
+            -p DynamicUser=1 \
+            --wait \
+            --pipe \
+            test ! -e '${CREDENTIALS_DIRECTORY}/test.creds.hoge:invalid'
+
+# Check if credentials with invalid names are not imported (with renaming).
+systemd-run -p "ImportCredentialEx=test.creds.*:renamed.creds." \
+            --unit=test-54-ImportCredential.service \
+            -p DynamicUser=1 \
+            --wait \
+            --pipe \
+            test ! -e '${CREDENTIALS_DIRECTORY}/renamed.creds.hoge:invalid'
 
 # Check that all valid credentials are imported.
 systemd-run -p "ImportCredential=test.creds.*" \