CHUNKING: Reject messages with malformed line ending. Bug 2000

[users/jgh/exim.git] / src / src / auths / dovecot.c

diff --git a/src/src/auths/dovecot.c b/src/src/auths/dovecot.c
index 0824240a03588d5b474ba35908a91a70ddb07caa..5bf7b9cc309d4766ba442fd75e51297c74c81511 100644 (file)
--- a/src/src/auths/dovecot.c
+++ b/src/src/auths/dovecot.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2004 Andrey Panin <pazke@donpac.ru>
 /*
  * Copyright (c) 2004 Andrey Panin <pazke@donpac.ru>

+ * Copyright (c) 2006-2016 The Exim Maintainers

  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published


@@ -12,12 +13,42 @@ commented them specially, but now they are getting quite extensive, so I have
 ceased doing that. The biggest change is to use unbuffered I/O on the socket
 because using C buffered I/O gives problems on some operating systems. PH */
 
 ceased doing that. The biggest change is to use unbuffered I/O on the socket
 because using C buffered I/O gives problems on some operating systems. PH */
 

+/* Protocol specifications:
+ * Dovecot 1, protocol version 1.1
+ *   http://wiki.dovecot.org/Authentication%20Protocol
+ *
+ * Dovecot 2, protocol version 1.1
+ *   http://wiki2.dovecot.org/Design/AuthProtocol
+ */
+

 #include "../exim.h"
 #include "dovecot.h"
 
 #define VERSION_MAJOR  1
 #define VERSION_MINOR  0
 
 #include "../exim.h"
 #include "dovecot.h"
 
 #define VERSION_MAJOR  1
 #define VERSION_MINOR  0
 

+/* http://wiki.dovecot.org/Authentication%20Protocol
+"The maximum line length isn't defined,
+ but it's currently expected to fit into 8192 bytes"
+*/
+#define DOVECOT_AUTH_MAXLINELEN 8192
+
+/* This was hard-coded as 8.
+AUTH req C->S sends {"AUTH", id, mechanism, service } + params, 5 defined for
+Dovecot 1; Dovecot 2 (same protocol version) defines 9.
+
+Master->Server sends {"USER", id, userid} + params, 6 defined.
+Server->Client only gives {"OK", id} + params, unspecified, only 1 guaranteed.
+
+We only define here to accept S->C; max seen is 3+<unspecified>, plus the two
+for the command and id, where unspecified might include _at least_ user=...
+
+So: allow for more fields than we ever expect to see, while aware that count
+can go up without changing protocol version.
+The cost is the length of an array of pointers on the stack.
+*/
+#define DOVECOT_AUTH_MAXFIELDCOUNT 16
+

 /* Options specific to the authentication mechanism. */
 optionlist auth_dovecot_options[] = {
        {
 /* Options specific to the authentication mechanism. */
 optionlist auth_dovecot_options[] = {
        {


@@ -43,7 +74,7 @@ auth_dovecot_options_block auth_dovecot_option_defaults = {
 /* Static variables for reading from the socket */
 
 static uschar sbuffer[256];
 /* Static variables for reading from the socket */
 
 static uschar sbuffer[256];

-static int sbp;
+static int socket_buffer_left;

 
 
 
 
 
 


@@ -67,9 +98,27 @@ void auth_dovecot_init(auth_instance *ablock)
        ablock->client = FALSE;
 }
 
        ablock->client = FALSE;
 }
 

-static int strcut(uschar *str, uschar **ptrs, int nptrs)
+/*************************************************
+ *    "strcut" to split apart server lines       *
+ *************************************************/
+
+/* Dovecot auth protocol uses TAB \t as delimiter; a line consists
+of a command-name, TAB, and then any parameters, each separated by a TAB.
+A parameter can be param=value or a bool, just param.
+
+This function modifies the original str in-place, inserting NUL characters.
+It initialises ptrs entries, setting all to NULL and only setting
+non-NULL N entries, where N is the return value, the number of fields seen
+(one more than the number of tabs).
+
+Note that the return value will always be at least 1, is the count of
+actual fields (so last valid offset into ptrs is one less).
+*/
+
+static int
+strcut(uschar *str, uschar **ptrs, int nptrs)

 {
 {

-       uschar *tmp = str;
+       uschar *last_sub_start = str;

        int n;
 
        for (n = 0; n < nptrs; n++)
        int n;
 
        for (n = 0; n < nptrs; n++)


@@ -79,19 +128,42 @@ static int strcut(uschar *str, uschar **ptrs, int nptrs)
        while (*str) {
                if (*str == '\t') {
                        if (n <= nptrs) {
        while (*str) {
                if (*str == '\t') {
                        if (n <= nptrs) {

-                               *ptrs++ = tmp;
-                               tmp = str + 1;
-                               *str = 0;
+                               *ptrs++ = last_sub_start;
+                               last_sub_start = str + 1;
+                               *str = '\0';

                        }
                        n++;
                }
                str++;
        }
 
                        }
                        n++;
                }
                str++;
        }
 

-       if (n < nptrs)
-               *ptrs = tmp;
+       /* It's acceptable for the string to end with a tab character.  We see
+       this in AUTH PLAIN without an initial response from the client, which
+       causing us to send "334 " and get the data from the client. */
+       if (n <= nptrs) {
+               *ptrs = last_sub_start;
+       } else {
+               HDEBUG(D_auth) debug_printf("dovecot: warning: too many results from tab-splitting; saw %d fields, room for %d\n", n, nptrs);
+               n = nptrs;
+       }

 
 

-       return n;
+       return n <= nptrs ? n : nptrs;
+}
+
+static void debug_strcut(uschar **ptrs, int nlen, int alen) ARG_UNUSED;
+static void
+debug_strcut(uschar **ptrs, int nlen, int alen)
+{
+        int i;
+        debug_printf("%d read but unreturned bytes; strcut() gave %d results: ",
+                        socket_buffer_left, nlen);
+        for (i = 0; i < nlen; i++) {
+                debug_printf(" {%s}", ptrs[i]);
+        }
+        if (nlen < alen)
+                debug_printf(" last is %s\n", ptrs[i] ? ptrs[i] : US"<null>");
+        else
+                debug_printf(" (max for capacity)\n");

 }
 
 #define CHECK_COMMAND(str, arg_min, arg_max) do { \
 }
 
 #define CHECK_COMMAND(str, arg_min, arg_max) do { \


@@ -125,27 +197,27 @@ int count = 0;
 
 for (;;)
   {
 
 for (;;)
   {

-  if (sbp == 0)
+  if (socket_buffer_left == 0)

     {
     {

-    sbp = read(fd, sbuffer, sizeof(sbuffer));
-    if (sbp == 0) { if (count == 0) return NULL; else break; }
+    socket_buffer_left = read(fd, sbuffer, sizeof(sbuffer));
+    if (socket_buffer_left == 0) { if (count == 0) return NULL; else break; }

     p = 0;
     }
 
     p = 0;
     }
 

-  while (p < sbp)
+  while (p < socket_buffer_left)

     {
     if (count >= n - 1) break;
     s[count++] = sbuffer[p];
     if (sbuffer[p++] == '\n') break;
     }
 
     {
     if (count >= n - 1) break;
     s[count++] = sbuffer[p];
     if (sbuffer[p++] == '\n') break;
     }
 

-  memmove(sbuffer, sbuffer + p, sbp - p);
-  sbp -= p;
+  memmove(sbuffer, sbuffer + p, socket_buffer_left - p);
+  socket_buffer_left -= p;

 
   if (s[count-1] == '\n' || count >= n - 1) break;
   }
 
 
   if (s[count-1] == '\n' || count >= n - 1) break;
   }
 

-s[count] = 0;
+s[count] = '\0';

 return s;
 }
 
 return s;
 }
 


@@ -156,224 +228,270 @@ return s;
 *              Server entry point                *
 *************************************************/
 
 *              Server entry point                *
 *************************************************/
 

-int auth_dovecot_server(auth_instance *ablock, uschar *data)
+int
+auth_dovecot_server(auth_instance * ablock, uschar * data)

 {
 {

-       auth_dovecot_options_block *ob =
-               (auth_dovecot_options_block *)(ablock->options_block);
-       struct sockaddr_un sa;
-       uschar buffer[4096];
-       uschar *args[8];
-       uschar *auth_command;
-       uschar *auth_extra_data = US"";
-       int nargs, tmp;
-       int cuid = 0, cont = 1, found = 0, fd, ret = DEFER;
-
-       HDEBUG(D_auth) debug_printf("dovecot authentication\n");
-
-       memset(&sa, 0, sizeof(sa));
-       sa.sun_family = AF_UNIX;
-
-       /* This was the original code here: it is nonsense because strncpy()
-       does not return an integer. I have converted this to use the function
-       that formats and checks length. PH */
-
-       /*
-       if (strncpy(sa.sun_path, ob->server_socket, sizeof(sa.sun_path)) < 0) {
-       */
-
-       if (!string_format(US sa.sun_path, sizeof(sa.sun_path), "%s",
-                          ob->server_socket)) {
-               auth_defer_msg = US"authentication socket path too long";
-               return DEFER;
-       }
+auth_dovecot_options_block *ob =
+       (auth_dovecot_options_block *) ablock->options_block;
+struct sockaddr_un sa;
+uschar buffer[DOVECOT_AUTH_MAXLINELEN];
+uschar *args[DOVECOT_AUTH_MAXFIELDCOUNT];
+uschar *auth_command;
+uschar *auth_extra_data = US"";
+uschar *p;
+int nargs, tmp;
+int crequid = 1, cont = 1, fd = -1, ret = DEFER;
+BOOL found = FALSE, have_mech_line = FALSE;
+
+HDEBUG(D_auth) debug_printf("dovecot authentication\n");
+
+if (!data)
+  {
+  ret = FAIL;
+  goto out;
+  }

 
 

-       auth_defer_msg = US"authentication socket connection error";
-
-       fd = socket(PF_UNIX, SOCK_STREAM, 0);
-       if (fd < 0)
-               return DEFER;
-
-       if (connect(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
-               goto out;
-
-       auth_defer_msg = US"authentication socket protocol error";
-
-       sbp = 0;  /* Socket buffer pointer */
-       while (cont) {
-               if (dc_gets(buffer, sizeof(buffer), fd) == NULL)
-                       OUT("authentication socket read error or premature eof");
-
-               buffer[Ustrlen(buffer) - 1] = 0;
-               HDEBUG(D_auth) debug_printf("received: %s\n", buffer);
-               nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0]));
-
-               /* Code below rewritten by Kirill Miazine (km@krot.org). Only check commands that
-                  Exim will need. Original code also failed if Dovecot server sent unknown
-                  command. E.g. COOKIE in version 1.1 of the protocol would cause troubles. */
-               if (Ustrcmp(args[0], US"CUID") == 0) {
-                       CHECK_COMMAND("CUID", 1, 1);
-                       cuid = Uatoi(args[1]);
-               } else if (Ustrcmp(args[0], US"VERSION") == 0) {
-                       CHECK_COMMAND("VERSION", 2, 2);
-                       if (Uatoi(args[1]) != VERSION_MAJOR)
-                               OUT("authentication socket protocol version mismatch");
-               } else if (Ustrcmp(args[0], US"MECH") == 0) {
-                       CHECK_COMMAND("MECH", 1, INT_MAX);
-                       if (strcmpic(US args[1], ablock->public_name) == 0)
-                               found = 1;
-               } else if (Ustrcmp(args[0], US"DONE") == 0) {
-                       CHECK_COMMAND("DONE", 0, 0);
-                       cont = 0;
-               }
-       }
+memset(&sa, 0, sizeof(sa));
+sa.sun_family = AF_UNIX;

 
 

-       if (!found)
-               goto out;
+/* This was the original code here: it is nonsense because strncpy()
+does not return an integer. I have converted this to use the function
+that formats and checks length. PH */

 
 

-       /* Added by PH: data must not contain tab (as it is
-       b64 it shouldn't, but check for safety). */
+/*
+if (strncpy(sa.sun_path, ob->server_socket, sizeof(sa.sun_path)) < 0) {
+}
+*/

 
 

-       if (Ustrchr(data, '\t') != NULL) {
-               ret = FAIL;
-               goto out;
-       }
+if (!string_format(US sa.sun_path, sizeof(sa.sun_path), "%s",
+                 ob->server_socket))
+  {
+  auth_defer_msg = US"authentication socket path too long";
+  return DEFER;
+  }

 
 

-       /* Added by PH: extra fields when TLS is in use or if the TCP/IP
-       connection is local. */
+auth_defer_msg = US"authentication socket connection error";

 
 

-       if (tls_in.cipher != NULL)
-               auth_extra_data = string_sprintf("secured\t%s%s",
-                   tls_in.certificate_verified? "valid-client-cert" : "",
-                   tls_in.certificate_verified? "\t" : "");
-       else if (interface_address != NULL &&
-                Ustrcmp(sender_host_address, interface_address) == 0)
-               auth_extra_data = US"secured\t";
+if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
+  return DEFER;

 
 

+if (connect(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
+  goto out;

 
 

-/****************************************************************************
-   The code below was the original code here. It didn't work. A reading of the
-   file auth-protocol.txt.gz that came with Dovecot 1.0_beta8 indicated that
-   this was not right. Maybe something changed. I changed it to move the
-   service indication into the AUTH command, and it seems to be better. PH
-
-       fprintf(f, "VERSION\t%d\t%d\r\nSERVICE\tSMTP\r\nCPID\t%d\r\n"
-               "AUTH\t%d\t%s\trip=%s\tlip=%s\tresp=%s\r\n",
-               VERSION_MAJOR, VERSION_MINOR, getpid(), cuid,
-               ablock->public_name, sender_host_address, interface_address,
-               data ? (char *) data : "");
-
-   Subsequently, the command was modified to add "secured" and "valid-client-
-   cert" when relevant.
-
-   The auth protocol is documented here:
-        http://wiki.dovecot.org/Authentication_Protocol
-****************************************************************************/
+auth_defer_msg = US"authentication socket protocol error";

 
 

-       auth_command = string_sprintf("VERSION\t%d\t%d\nCPID\t%d\n"
-               "AUTH\t%d\t%s\tservice=smtp\t%srip=%s\tlip=%s\tnologin\tresp=%s\n",
-               VERSION_MAJOR, VERSION_MINOR, getpid(), cuid,
-               ablock->public_name, auth_extra_data, sender_host_address,
-               interface_address, data ? (char *) data : "");
+socket_buffer_left = 0;  /* Global, used to read more than a line but return by line */
+while (cont)
+  {
+  if (dc_gets(buffer, sizeof(buffer), fd) == NULL)
+    OUT("authentication socket read error or premature eof");
+  p = buffer + Ustrlen(buffer) - 1;
+  if (*p != '\n')
+    OUT("authentication socket protocol line too long");
+
+  *p = '\0';
+  HDEBUG(D_auth) debug_printf("received: %s\n", buffer);
+
+  nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0]));
+
+  /* HDEBUG(D_auth) debug_strcut(args, nargs, sizeof(args) / sizeof(args[0])); */
+
+  /* Code below rewritten by Kirill Miazine (km@krot.org). Only check commands that
+    Exim will need. Original code also failed if Dovecot server sent unknown
+    command. E.g. COOKIE in version 1.1 of the protocol would cause troubles. */
+  /* pdp: note that CUID is a per-connection identifier sent by the server,
+    which increments at server discretion.
+    By contrast, the "id" field of the protocol is a connection-specific request
+    identifier, which needs to be unique per request from the client and is not
+    connected to the CUID value, so we ignore CUID from server.  It's purely for
+    diagnostics. */
+
+  if (Ustrcmp(args[0], US"VERSION") == 0)
+    {
+    CHECK_COMMAND("VERSION", 2, 2);
+    if (Uatoi(args[1]) != VERSION_MAJOR)
+      OUT("authentication socket protocol version mismatch");
+    }
+  else if (Ustrcmp(args[0], US"MECH") == 0)
+    {
+    CHECK_COMMAND("MECH", 1, INT_MAX);
+    have_mech_line = TRUE;
+    if (strcmpic(US args[1], ablock->public_name) == 0)
+      found = TRUE;
+    }
+  else if (Ustrcmp(args[0], US"SPID") == 0)
+    {
+    /* Unfortunately the auth protocol handshake wasn't designed well
+    to differentiate between auth-client/userdb/master. auth-userdb
+    and auth-master send VERSION + SPID lines only and nothing
+    afterwards, while auth-client sends VERSION + MECH + SPID +
+    CUID + more. The simplest way that we can determine if we've
+    connected to the correct socket is to see if MECH line exists or
+    not (alternatively we'd have to have a small timeout after SPID
+    to see if CUID is sent or not). */
+
+    if (!have_mech_line)
+      OUT("authentication socket type mismatch"
+       " (connected to auth-master instead of auth-client)");
+    }
+  else if (Ustrcmp(args[0], US"DONE") == 0)
+    {
+    CHECK_COMMAND("DONE", 0, 0);
+    cont = 0;
+    }
+  }

 
 

-       if (write(fd, auth_command, Ustrlen(auth_command)) < 0)
-              HDEBUG(D_auth) debug_printf("error sending auth_command: %s\n",
-                strerror(errno));
+if (!found)
+  {
+  auth_defer_msg = string_sprintf(
+    "Dovecot did not advertise mechanism \"%s\" to us", ablock->public_name);
+  goto out;
+  }

 
 

-       HDEBUG(D_auth) debug_printf("sent: %s", auth_command);
+/* Added by PH: data must not contain tab (as it is
+b64 it shouldn't, but check for safety). */

 
 

-       while (1) {
-               uschar *temp;
-               uschar *auth_id_pre = NULL;
-               int i;
+if (Ustrchr(data, '\t') != NULL)
+  {
+  ret = FAIL;
+  goto out;
+  }

 
 

-               if (dc_gets(buffer, sizeof(buffer), fd) == NULL) {
-                       auth_defer_msg = US"authentication socket read error or premature eof";
-                       goto out;
-               }
+/* Added by PH: extra fields when TLS is in use or if the TCP/IP
+connection is local. */

 
 

-               buffer[Ustrlen(buffer) - 1] = 0;
-               HDEBUG(D_auth) debug_printf("received: %s\n", buffer);
-               nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0]));
+if (tls_in.cipher != NULL)
+  auth_extra_data = string_sprintf("secured\t%s%s",
+     tls_in.certificate_verified? "valid-client-cert" : "",
+     tls_in.certificate_verified? "\t" : "");

 
 

-               if (Uatoi(args[1]) != cuid)
-                       OUT("authentication socket connection id mismatch");
+else if (  interface_address != NULL
+        && Ustrcmp(sender_host_address, interface_address) == 0)
+  auth_extra_data = US"secured\t";

 
 

-               switch (toupper(*args[0])) {
-               case 'C':
-                       CHECK_COMMAND("CONT", 1, 2);

 
 

-                       tmp = auth_get_no64_data(&data, US args[2]);
-                       if (tmp != OK) {
-                               ret = tmp;
-                               goto out;
-                       }
+/****************************************************************************
+The code below was the original code here. It didn't work. A reading of the
+file auth-protocol.txt.gz that came with Dovecot 1.0_beta8 indicated that
+this was not right. Maybe something changed. I changed it to move the
+service indication into the AUTH command, and it seems to be better. PH
+
+fprintf(f, "VERSION\t%d\t%d\r\nSERVICE\tSMTP\r\nCPID\t%d\r\n"
+       "AUTH\t%d\t%s\trip=%s\tlip=%s\tresp=%s\r\n",
+       VERSION_MAJOR, VERSION_MINOR, getpid(), cuid,
+       ablock->public_name, sender_host_address, interface_address,
+       data ? (char *) data : "");
+
+Subsequently, the command was modified to add "secured" and "valid-client-
+cert" when relevant.
+****************************************************************************/

 
 

-                       /* Added by PH: data must not contain tab (as it is
-                       b64 it shouldn't, but check for safety). */
+auth_command = string_sprintf("VERSION\t%d\t%d\nCPID\t%d\n"
+       "AUTH\t%d\t%s\tservice=smtp\t%srip=%s\tlip=%s\tnologin\tresp=%s\n",
+       VERSION_MAJOR, VERSION_MINOR, getpid(), crequid,
+       ablock->public_name, auth_extra_data, sender_host_address,
+       interface_address, data);

 
 

-                       if (Ustrchr(data, '\t') != NULL) {
-                               ret = FAIL;
-                               goto out;
-                       }
+if (write(fd, auth_command, Ustrlen(auth_command)) < 0)
+  HDEBUG(D_auth) debug_printf("error sending auth_command: %s\n",
+    strerror(errno));

 
 

-                       temp = string_sprintf("CONT\t%d\t%s\n", cuid, data);
-                       if (write(fd, temp, Ustrlen(temp)) < 0)
-                               OUT("authentication socket write error");
-                       break;
-
-               case 'F':
-                       CHECK_COMMAND("FAIL", 1, -1);
-
-                       for (i=2; (i<nargs) && (auth_id_pre == NULL); i++)
-                       {
-                               if ( Ustrncmp(args[i], US"user=", 5) == 0 )
-                               {
-                                       auth_id_pre = args[i]+5;
-                                       expand_nstring[1] = auth_vars[0] =
-                                               string_copy(auth_id_pre); /* PH */
-                                       expand_nlength[1] = Ustrlen(auth_id_pre);
-                                       expand_nmax = 1;
-                               }
-                       }
+HDEBUG(D_auth) debug_printf("sent: %s", auth_command);

 
 

-                       ret = FAIL;
-                       goto out;
-
-               case 'O':
-                       CHECK_COMMAND("OK", 2, -1);
-
-                       /*
-                        * Search for the "user=$USER" string in the args array
-                        * and return the proper value.
-                        */
-                       for (i=2; (i<nargs) && (auth_id_pre == NULL); i++)
-                       {
-                               if ( Ustrncmp(args[i], US"user=", 5) == 0 )
-                               {
-                                       auth_id_pre = args[i]+5;
-                                       expand_nstring[1] = auth_vars[0] =
-                                               string_copy(auth_id_pre); /* PH */
-                                       expand_nlength[1] = Ustrlen(auth_id_pre);
-                                       expand_nmax = 1;
-                               }
-                       }
+while (1)
+  {
+  uschar *temp;
+  uschar *auth_id_pre = NULL;
+  int i;

 
 

-                       if (auth_id_pre == NULL)
-                               OUT("authentication socket protocol error, username missing");
+  if (dc_gets(buffer, sizeof(buffer), fd) == NULL)
+    {
+    auth_defer_msg = US"authentication socket read error or premature eof";
+    goto out;
+    }

 
 

-                       ret = OK;
-                       /* fallthrough */
+  buffer[Ustrlen(buffer) - 1] = 0;
+  HDEBUG(D_auth) debug_printf("received: %s\n", buffer);
+  nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0]));

 
 

-               default:
-                       goto out;
-               }
-       }
+  if (Uatoi(args[1]) != crequid)
+    OUT("authentication socket connection id mismatch");
+
+  switch (toupper(*args[0]))
+    {
+    case 'C':
+      CHECK_COMMAND("CONT", 1, 2);
+
+      if ((tmp = auth_get_no64_data(&data, US args[2])) != OK)
+       {
+       ret = tmp;
+       goto out;
+       }
+
+      /* Added by PH: data must not contain tab (as it is
+      b64 it shouldn't, but check for safety). */
+
+      if (Ustrchr(data, '\t') != NULL)
+        {
+       ret = FAIL;
+       goto out;
+       }
+
+      temp = string_sprintf("CONT\t%d\t%s\n", crequid, data);
+      if (write(fd, temp, Ustrlen(temp)) < 0)
+       OUT("authentication socket write error");
+      break;
+
+    case 'F':
+      CHECK_COMMAND("FAIL", 1, -1);
+
+      for (i=2; (i<nargs) && (auth_id_pre == NULL); i++)
+       {
+       if ( Ustrncmp(args[i], US"user=", 5) == 0 )
+         {
+         auth_id_pre = args[i]+5;
+         expand_nstring[1] = auth_vars[0] = string_copy(auth_id_pre); /* PH */
+         expand_nlength[1] = Ustrlen(auth_id_pre);
+         expand_nmax = 1;
+         }
+       }
+
+      ret = FAIL;
+      goto out;
+
+    case 'O':
+      CHECK_COMMAND("OK", 2, -1);
+
+      /* Search for the "user=$USER" string in the args array
+      and return the proper value.  */
+
+      for (i=2; (i<nargs) && (auth_id_pre == NULL); i++)
+       {
+       if ( Ustrncmp(args[i], US"user=", 5) == 0 )
+         {
+         auth_id_pre = args[i]+5;
+         expand_nstring[1] = auth_vars[0] = string_copy(auth_id_pre); /* PH */
+         expand_nlength[1] = Ustrlen(auth_id_pre);
+         expand_nmax = 1;
+         }
+       }
+
+      if (auth_id_pre == NULL)
+        OUT("authentication socket protocol error, username missing");
+
+      ret = OK;
+      /* fallthrough */
+
+    default:
+      goto out;
+    }
+  }

 
 out:
 
 out:

-       /* close the socket used by dovecot */
-       if (fd >= 0)
-              close(fd);
+/* close the socket used by dovecot */
+if (fd >= 0)
+  close(fd);

 
 

-       /* Expand server_condition as an authorization check */
-       return (ret == OK)? auth_check_serv_cond(ablock) : ret;
+/* Expand server_condition as an authorization check */
+return ret == OK ? auth_check_serv_cond(ablock) : ret;

 }
 }