1 files changed, 179 insertions, 0 deletions
diff --git a/src/auths/plaintext.c b/src/auths/plaintext.c
new file mode 100644
index 0000000..58d1783
--- /dev/null
+++ b/src/auths/plaintext.c
@@ -0,0 +1,179 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 - 2021 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+#include "../exim.h"
+#include "plaintext.h"
+
+
+/* Options specific to the plaintext authentication mechanism. */
+
+optionlist auth_plaintext_options[] = {
+  { "client_ignore_invalid_base64", opt_bool,
+      OPT_OFF(auth_plaintext_options_block, client_ignore_invalid_base64) },
+  { "client_send",        opt_stringptr,
+      OPT_OFF(auth_plaintext_options_block, client_send) },
+  { "server_prompts",     opt_stringptr,
+      OPT_OFF(auth_plaintext_options_block, server_prompts) }
+};
+
+/* Size of the options list. An extern variable has to be used so that its
+address can appear in the tables drtables.c. */
+
+int auth_plaintext_options_count =
+  sizeof(auth_plaintext_options)/sizeof(optionlist);
+
+/* Default private options block for the plaintext authentication method. */
+
+auth_plaintext_options_block auth_plaintext_option_defaults = {
+  NULL,              /* server_prompts */
+  NULL,              /* client_send */
+  FALSE              /* client_ignore_invalid_base64 */
+};
+
+
+#ifdef MACRO_PREDEF
+
+/* Dummy values */
+void auth_plaintext_init(auth_instance *ablock) {}
+int auth_plaintext_server(auth_instance *ablock, uschar *data) {return 0;}
+int auth_plaintext_client(auth_instance *ablock, void * sx, int timeout,
+    uschar *buffer, int buffsize) {return 0;}
+
+#else   /*!MACRO_PREDEF*/
+
+
+
+/*************************************************
+*          Initialization entry point            *
+*************************************************/
+
+/* Called for each instance, after its options have been read, to
+enable consistency checks to be done, or anything else that needs
+to be set up. */
+
+void
+auth_plaintext_init(auth_instance *ablock)
+{
+auth_plaintext_options_block *ob =
+  (auth_plaintext_options_block *)(ablock->options_block);
+if (ablock->public_name == NULL) ablock->public_name = ablock->name;
+if (ablock->server_condition != NULL) ablock->server = TRUE;
+if (ob->client_send != NULL) ablock->client = TRUE;
+}
+
+
+
+/*************************************************
+*             Server entry point                 *
+*************************************************/
+
+/* For interface, see auths/README */
+
+int
+auth_plaintext_server(auth_instance * ablock, uschar * data)
+{
+auth_plaintext_options_block * ob =
+  (auth_plaintext_options_block *)(ablock->options_block);
+const uschar * prompts = ob->server_prompts;
+uschar * s;
+int number = 1;
+int rc;
+int sep = 0;
+
+/* Expand a non-empty list of prompt strings */
+
+if (prompts)
+  if (!(prompts = expand_cstring(prompts)))
+    {
+    auth_defer_msg = expand_string_message;
+    return DEFER;
+    }
+
+/* If data was supplied on the AUTH command, decode it, and split it up into
+multiple items at binary zeros. The strings are put into $auth1, $auth2, etc,
+up to a maximum. To retain backwards compatibility, they are also put int $1,
+$2, etc. If the data consists of the string "=" it indicates a single, empty
+string. */
+
+if (*data)
+  if ((rc = auth_read_input(data)) != OK)
+    return rc;
+
+/* Now go through the list of prompt strings. Skip over any whose data has
+already been provided as part of the AUTH command. For the rest, send them
+out as prompts, and get a data item back. If the data item is "*", abandon the
+authentication attempt. Otherwise, split it into items as above. */
+
+while (  (s = string_nextinlist(&prompts, &sep, NULL, 0))
+      && expand_nmax < EXPAND_MAXN)
+  if (number++ > expand_nmax)
+    if ((rc = auth_prompt(CUS s)) != OK)
+      return rc;
+
+/* We now have a number of items of data in $auth1, $auth2, etc (and also, for
+compatibility, in $1, $2, etc). Authentication and authorization are handled
+together for this authenticator by expanding the server_condition option. Note
+that ablock->server_condition is always non-NULL because that's what configures
+this authenticator as a server. */
+
+return auth_check_serv_cond(ablock);
+}
+
+
+
+/*************************************************
+*              Client entry point                *
+*************************************************/
+
+/* For interface, see auths/README */
+
+int
+auth_plaintext_client(
+  auth_instance *ablock,                 /* authenticator block */
+  void * sx,				 /* smtp connextion */
+  int timeout,                           /* command timeout */
+  uschar *buffer,                        /* buffer for reading response */
+  int buffsize)                          /* size of buffer */
+{
+auth_plaintext_options_block *ob =
+  (auth_plaintext_options_block *)(ablock->options_block);
+const uschar * text = ob->client_send;
+const uschar * s;
+int sep = 0;
+int auth_var_idx = 0, rc;
+int flags = AUTH_ITEM_FIRST;
+
+if (ob->client_ignore_invalid_base64)
+  flags |= AUTH_ITEM_IGN64;
+
+/* The text is broken up into a number of different data items, which are
+sent one by one. The first one is sent with the AUTH command; the remainder are
+sent in response to subsequent prompts. Each is expanded before being sent. */
+
+while ((s = string_nextinlist(&text, &sep, NULL, 0)))
+  {
+  if (!text)
+    flags |= AUTH_ITEM_LAST;
+
+  if ((rc = auth_client_item(sx, ablock, &s, flags, timeout, buffer, buffsize))
+       != DEFER)
+    return rc;
+
+  flags &= ~AUTH_ITEM_FIRST;
+
+  if (auth_var_idx < AUTH_VARS)
+    auth_vars[auth_var_idx++] = string_copy(s);
+  }
+
+/* Control should never actually get here. */
+
+return FAIL;
+}
+
+#endif   /*!MACRO_PREDEF*/
+/* End of plaintext.c */