src/src/auths/plaintext.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #include "../exim.h"
   9 #include "plaintext.h"
  10
  11
  12 /* Options specific to the plaintext authentication mechanism. */
  13
  14 optionlist auth_plaintext_options[] = {
  15   { "client_ignore_invalid_base64", opt_bool,
  16       (void *)(offsetof(auth_plaintext_options_block, client_ignore_invalid_base64)) },
  17   { "client_send",        opt_stringptr,
  18       (void *)(offsetof(auth_plaintext_options_block, client_send)) },
  19   { "server_prompts",     opt_stringptr,
  20       (void *)(offsetof(auth_plaintext_options_block, server_prompts)) }
  21 };
  22
  23 /* Size of the options list. An extern variable has to be used so that its
  24 address can appear in the tables drtables.c. */
  25
  26 int auth_plaintext_options_count =
  27   sizeof(auth_plaintext_options)/sizeof(optionlist);
  28
  29 /* Default private options block for the plaintext authentication method. */
  30
  31 auth_plaintext_options_block auth_plaintext_option_defaults = {
  32   NULL,              /* server_prompts */
  33   NULL,              /* client_send */
  34   FALSE              /* client_ignore_invalid_base64 */
  35 };
  36
  37
  38 #ifdef MACRO_PREDEF
  39
  40 /* Dummy values */
  41 void auth_plaintext_init(auth_instance *ablock) {}
  42 int auth_plaintext_server(auth_instance *ablock, uschar *data) {return 0;}
  43 int auth_plaintext_client(auth_instance *ablock, void * sx, int timeout,
  44     uschar *buffer, int buffsize) {return 0;}
  45
  46 #else   /*!MACRO_PREDEF*/
  47
  48
  49
  50 /*************************************************
  51 *          Initialization entry point            *
  52 *************************************************/
  53
  54 /* Called for each instance, after its options have been read, to
  55 enable consistency checks to be done, or anything else that needs
  56 to be set up. */
  57
  58 void
  59 auth_plaintext_init(auth_instance *ablock)
  60 {
  61 auth_plaintext_options_block *ob =
  62   (auth_plaintext_options_block *)(ablock->options_block);
  63 if (ablock->public_name == NULL) ablock->public_name = ablock->name;
  64 if (ablock->server_condition != NULL) ablock->server = TRUE;
  65 if (ob->client_send != NULL) ablock->client = TRUE;
  66 }
  67
  68
  69
  70 /*************************************************
  71 *             Server entry point                 *
  72 *************************************************/
  73
  74 /* For interface, see auths/README */
  75
  76 int
  77 auth_plaintext_server(auth_instance * ablock, uschar * data)
  78 {
  79 auth_plaintext_options_block * ob =
  80   (auth_plaintext_options_block *)(ablock->options_block);
  81 const uschar * prompts = ob->server_prompts;
  82 uschar * s;
  83 int number = 1;
  84 int rc;
  85 int sep = 0;
  86
  87 /* Expand a non-empty list of prompt strings */
  88
  89 if (prompts)
  90   if (!(prompts = expand_cstring(prompts)))
  91     {
  92     auth_defer_msg = expand_string_message;
  93     return DEFER;
  94     }
  95
  96 /* If data was supplied on the AUTH command, decode it, and split it up into
  97 multiple items at binary zeros. The strings are put into $auth1, $auth2, etc,
  98 up to a maximum. To retain backwards compatibility, they are also put int $1,
  99 $2, etc. If the data consists of the string "=" it indicates a single, empty
 100 string. */
 101
 102 if (*data)
 103   if ((rc = auth_read_input(data)) != OK)
 104     return rc;
 105
 106 /* Now go through the list of prompt strings. Skip over any whose data has
 107 already been provided as part of the AUTH command. For the rest, send them
 108 out as prompts, and get a data item back. If the data item is "*", abandon the
 109 authentication attempt. Otherwise, split it into items as above. */
 110
 111 while (  (s = string_nextinlist(&prompts, &sep, big_buffer, big_buffer_size))
 112       && expand_nmax < EXPAND_MAXN)
 113   if (number++ > expand_nmax)
 114     if ((rc = auth_prompt(CUS s)) != OK)
 115       return rc;
 116
 117 /* We now have a number of items of data in $auth1, $auth2, etc (and also, for
 118 compatibility, in $1, $2, etc). Authentication and authorization are handled
 119 together for this authenticator by expanding the server_condition option. Note
 120 that ablock->server_condition is always non-NULL because that's what configures
 121 this authenticator as a server. */
 122
 123 return auth_check_serv_cond(ablock);
 124 }
 125
 126
 127
 128 /*************************************************
 129 *              Client entry point                *
 130 *************************************************/
 131
 132 /* For interface, see auths/README */
 133
 134 int
 135 auth_plaintext_client(
 136   auth_instance *ablock,                 /* authenticator block */
 137   void * sx,                             /* smtp connextion */
 138   int timeout,                           /* command timeout */
 139   uschar *buffer,                        /* buffer for reading response */
 140   int buffsize)                          /* size of buffer */
 141 {
 142 auth_plaintext_options_block *ob =
 143   (auth_plaintext_options_block *)(ablock->options_block);
 144 const uschar * text = ob->client_send;
 145 const uschar * s;
 146 int sep = 0;
 147 int auth_var_idx = 0, rc;
 148 int flags = AUTH_ITEM_FIRST;
 149
 150 if (ob->client_ignore_invalid_base64)
 151   flags |= AUTH_ITEM_IGN64;
 152
 153 /* The text is broken up into a number of different data items, which are
 154 sent one by one. The first one is sent with the AUTH command; the remainder are
 155 sent in response to subsequent prompts. Each is expanded before being sent. */
 156
 157 while ((s = string_nextinlist(&text, &sep, NULL, 0)))
 158   {
 159   if (!text)
 160     flags |= AUTH_ITEM_LAST;
 161
 162   if ((rc = auth_client_item(sx, ablock, &s, flags, timeout, buffer, buffsize))
 163        != DEFER)
 164     return rc;
 165
 166   flags &= ~AUTH_ITEM_FIRST;
 167
 168   if (auth_var_idx < AUTH_VARS)
 169     auth_vars[auth_var_idx++] = string_copy(s);
 170   }
 171
 172 /* Control should never actually get here. */
 173
 174 return FAIL;
 175 }
 176
 177 #endif   /*!MACRO_PREDEF*/
 178 /* End of plaintext.c */