challenger

commit 1368bc38840eddc9eb3718b6253b830109c86907
parent 10d8e79e54ecbba07f9f9f9cb0f119ab6817ee74
Author: Florian Dold <dold@taler.net>
Date:   Thu, 27 Aug 2026 23:45:34 +0200

challenger: allow arguments in TAN helper commands

Diffstat:
A
src/challenger/cat-with-args.sh
 | 
8
++++++++
M
src/challenger/challenger-httpd_challenge.c
 | 
67
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------
M
src/challenger/challenger.conf
 | 
1
+
M
src/challenger/meson.build
 | 
6
++++++
M
src/challenger/test-challenger.conf
 | 
2
+-

5 files changed, 77 insertions(+), 7 deletions(-)
diff --git a/src/challenger/cat-with-args.sh b/src/challenger/cat-with-args.sh
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# This file is in the public domain.
+if [ "$1" != "--test-command-argument" ]
+then
+    exit 40
+fi
+cat - > "$(printf '%s\n' "$2" | jq -r ".filename")"
+exit 0
diff --git a/src/challenger/challenger-httpd_challenge.c b/src/challenger/challenger-httpd_challenge.c
@@ -415,6 +415,51 @@ child_done_cb (void *cls,
 
 
 /**
+ * Resolve a binary name via PATH.
+ *
+ * Needed because the GNUnet process helpers do not support
+ * an execp equivalent at present.
+ *
+ * @param binary_name name to search for
+ * @return resolved path, NULL if the binary was not found
+ */
+static char *
+resolve_path (const char *binary_name)
+{
+  char *path_env;
+  char full_path[2048];
+  char *dir;
+  char *path_copy;
+
+  if (NULL != strchr (binary_name,
+                      '/'))
+    return GNUNET_strdup (binary_name);
+  path_env = getenv ("PATH");
+  if (NULL == path_env)
+    return NULL;
+  path_copy = GNUNET_strdup (path_env);
+  dir = strtok (path_copy, ":");
+  while (NULL != dir)
+  {
+    snprintf (full_path,
+              sizeof(full_path),
+              "%s/%s",
+              dir,
+              binary_name);
+    if (0 == access (full_path,
+                     X_OK))
+    {
+      GNUNET_free (path_copy);
+      return GNUNET_strdup (full_path);
+    }
+    dir = strtok (NULL, ":");
+  }
+  GNUNET_free (path_copy);
+  return NULL;
+}
+
+
+/**
  * Transmit the TAN to the given address.
  *
  * @param[in,out] bc context to submit TAN for
@@ -445,9 +490,16 @@ send_tan (struct ChallengeContext *bc)
   }
   {
     char *address;
+    char *binary_path = NULL;
+    char **cmd_argv;
+    const char *extra_args[2];
 
     address = json_dumps (bc->address,
                           JSON_COMPACT);
+    extra_args[0] = address;
+    extra_args[1] = NULL;
+    cmd_argv = TALER_words_split (CH_auth_command,
+                                  extra_args);
 #if DEBUG
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Running auth command `%s' on address `%s'\n",
@@ -460,18 +512,21 @@ send_tan (struct ChallengeContext *bc)
                      bc->child,
                      GNUNET_process_option_inherit_rpipe (p,
                                                           STDIN_FILENO)));
-    if (GNUNET_OK !=
-        GNUNET_process_run_command_va (bc->child,
-                                       CH_auth_command,
-                                       CH_auth_command,
-                                       address,
-                                       NULL))
+    if (NULL != cmd_argv[0])
+      binary_path = resolve_path (cmd_argv[0]);
+    if ( (NULL == binary_path) ||
+         (GNUNET_OK !=
+          GNUNET_process_run_command_argv (bc->child,
+                                           binary_path,
+                                           (const char **) cmd_argv)) )
     {
       GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
                            "exec");
       GNUNET_process_destroy (bc->child);
       bc->child = NULL;
     }
+    GNUNET_free (binary_path);
+    TALER_words_destroy (cmd_argv);
     free (address);
   }
   if (NULL == bc->child)
diff --git a/src/challenger/challenger.conf b/src/challenger/challenger.conf
@@ -44,6 +44,7 @@ BASE_URL = http://localhost:9967/
 MESSAGE_TEMPLATE_FILE = ${DATADIR}templates/default-challenge-message.txt
 
 # Which external command should be used to transmit challenges?
+# The command may include arguments separated by spaces.
 # Example commands are challenger-send-{sms,email,post}.sh
 # AUTH_COMMAND =
 AUTH_COMMAND = /usr/bin/true
diff --git a/src/challenger/meson.build b/src/challenger/meson.build
@@ -28,6 +28,12 @@ check_SCRIPTS = [
 
 test_helper_cat = configure_file(input: 'cat.sh', output: 'cat.sh', copy: true)
 
+test_helper_cat_with_args = configure_file(
+    input: 'cat-with-args.sh',
+    output: 'cat-with-args.sh',
+    copy: true,
+)
+
 test_conf = configure_file(
     input: 'test-challenger.conf',
     output: 'test-challenger.conf',
diff --git a/src/challenger/test-challenger.conf b/src/challenger/test-challenger.conf
@@ -1,7 +1,7 @@
 [challenger]
 
 # Which external command should be used to transmit challenges?
-AUTH_COMMAND = cat.sh
+AUTH_COMMAND = cat-with-args.sh --test-command-argument
 
 # What address type are we validating? (SMS, e-mail, etc.)
 ADDRESS_TYPE = file-access