conf: add set selection to ntstrustedcerts

Add an optional set-ID argument to the ntstrustedcerts directive to
enable multiple sets of trusted certificates to be specified.

conf.c

@@ -262,6 +262,7 @@ static int nts_server_connections = 100;
 static int nts_refresh = 2419200; /* 4 weeks */
 static int nts_rotate = 604800; /* 1 week */
 static ARR_Instance nts_trusted_certs_paths; /* array of (char *) */
+static ARR_Instance nts_trusted_certs_ids; /* array of uint32_t */
 
 /* Number of clock updates needed to enable certificate time checks */
 static int no_cert_time_check = 0;
@@ -393,6 +394,7 @@ CNF_Initialise(int r, int client_only)
   nts_server_cert_files = ARR_CreateInstance(sizeof (char *));
   nts_server_key_files = ARR_CreateInstance(sizeof (char *));
   nts_trusted_certs_paths = ARR_CreateInstance(sizeof (char *));
+  nts_trusted_certs_ids = ARR_CreateInstance(sizeof (uint32_t));
 
   rtc_device = Strdup(DEFAULT_RTC_DEVICE);
   hwclock_file = Strdup(DEFAULT_HWCLOCK_FILE);
@@ -452,6 +454,7 @@ CNF_Finalise(void)
   ARR_DestroyInstance(nts_server_cert_files);
   ARR_DestroyInstance(nts_server_key_files);
   ARR_DestroyInstance(nts_trusted_certs_paths);
+  ARR_DestroyInstance(nts_trusted_certs_ids);
 
   Free(drift_file);
   Free(dumpdir);
@@ -1185,10 +1188,23 @@ parse_ntsserver(char *line, ARR_Instance files)
 static void
 parse_ntstrustedcerts(char *line)
 {
-  char *path = NULL;
+  uint32_t id;
+  char *path;
+
+  if (get_number_of_args(line) == 2) {
+    path = CPS_SplitWord(line);
+    if (sscanf(line, "%"SCNu32, &id) != 1)
+      command_parse_error();
+  } else {
+    check_number_of_args(line, 1);
+    path = line;
+    id = 0;
+  }
+
+  path = Strdup(path);
 
-  parse_string(line, &path);
   ARR_AppendElement(nts_trusted_certs_paths, &path);
+  ARR_AppendElement(nts_trusted_certs_ids, &id);
 }
 
 /* ================================================== */
@@ -2605,9 +2621,13 @@ CNF_GetNtsRotate(void)
 /* ================================================== */
 
 int
-CNF_GetNtsTrustedCertsPaths(const char ***paths)
+CNF_GetNtsTrustedCertsPaths(const char ***paths, uint32_t **ids)
 {
   *paths = ARR_GetElements(nts_trusted_certs_paths);
+  *ids = ARR_GetElements(nts_trusted_certs_ids);
+
+  if (ARR_GetSize(nts_trusted_certs_paths) != ARR_GetSize(nts_trusted_certs_ids))
+    assert(0);
 
   return ARR_GetSize(nts_trusted_certs_paths);
 }

conf.h

@@ -159,7 +159,7 @@ extern int CNF_GetNtsServerProcesses(void);
 extern int CNF_GetNtsServerConnections(void);
 extern int CNF_GetNtsRefresh(void);
 extern int CNF_GetNtsRotate(void);
-extern int CNF_GetNtsTrustedCertsPaths(const char ***paths);
+extern int CNF_GetNtsTrustedCertsPaths(const char ***paths, uint32_t **ids);
 extern int CNF_GetNoSystemCert(void);
 extern int CNF_GetNoCertTimeCheck(void);
 

doc/chrony.conf.adoc

@@ -750,14 +750,29 @@ This directive specifies the maximum interval between NTS-KE handshakes (in
 seconds) in order to refresh the keys authenticating NTP packets. The default
 value is 2419200 (4 weeks).
 
-[[ntstrustedcerts]]*ntstrustedcerts* _file_|_directory_::
+[[ntstrustedcerts]]*ntstrustedcerts* [_set-ID_] _file_|_directory_::
 This directive specifies a file or directory containing certificates (in the
-PEM format) of trusted certificate authorities (CA) that should be used to
-verify certificates of NTS servers in addition to the system's default trusted
-CAs (if the *nosystemcert* directive is not present).
+PEM format) of trusted certificate authorities (CA) which can be used to
+verify certificates of NTS servers.
 +
-This directive can be used multiple times to specify multiple files and/or
-directories with trusted certificates.
+The optional _set-ID_ argument is a number in the range 0 through 2^32-1, which
+selects the set of certificates where certificates from the specified file
+or directory are added. The default ID is 0, which is a set containing the
+system's default trusted CAs (unless the *nosystemcert* directive is present).
+All other sets are empty by default.
++
+This directive can be used multiple times to specify one or more sets of
+trusted certificates, each containing certificates from one or more files
+and/or directories.
++
+An example is:
++
+----
+ntstrustedcerts /etc/pki/nts/foo.crt
+ntstrustedcerts 1 /etc/pki/nts/bar.crt
+ntstrustedcerts 1 /etc/pki/nts/baz.crt
+ntstrustedcerts 2 /etc/pki/nts/qux.crt
+----
 
 [[nosystemcert]]*nosystemcert*::
 This directive disables the system's default trusted CAs.

nts_ke_client.c

@@ -283,9 +283,7 @@ NKC_CreateInstance(IPSockAddr *address, const char *name, uint32_t cert_set)
   inst->destroying = 0;
   inst->got_response = 0;
 
-  n_certs = CNF_GetNtsTrustedCertsPaths(&trusted_certs);
-  certs_ids = MallocArray(uint32_t, n_certs);
-  memset(certs_ids, 0, sizeof (uint32_t) * n_certs);
+  n_certs = CNF_GetNtsTrustedCertsPaths(&trusted_certs, &certs_ids);
 
   /* Share the credentials among clients using the default set of trusted
      certificates, which likely contains most certificates */
@@ -301,8 +299,6 @@ NKC_CreateInstance(IPSockAddr *address, const char *name, uint32_t cert_set)
                                                          n_certs, cert_set);
   }
 
-  Free(certs_ids);
-
   return inst;
 }