move authentication_windows_client and mysql_clear_password clear client auth plugins

out of libmysql into separate dynamic plugins in the plugin/ directory.

move dialog and auth_socket plugins out of the plugin directory with examples into
dedicated directories in plugin/

7 files changed, 908 insertions, 0 deletions

diff --git a/plugin/auth_examples/CMakeLists.txt b/plugin/auth_examples/CMakeLists.txt
new file mode 100644
index 00000000000..0c9fb32b77a
--- /dev/null
+++ b/plugin/auth_examples/CMakeLists.txt
@@ -0,0 +1,31 @@
+# Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+# 
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; version 2 of the
+# License.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
+
+MYSQL_ADD_PLUGIN(dialog_examples dialog_examples.c 
+  MODULE_ONLY)
+MYSQL_ADD_PLUGIN(auth_test_plugin test_plugin.c 
+  MODULE_ONLY)
+MYSQL_ADD_PLUGIN(qa_auth_interface qa_auth_interface.c
+  MODULE_ONLY)
+
+MYSQL_ADD_PLUGIN(qa_auth_server qa_auth_server.c
+  MODULE_ONLY)
+
+MYSQL_ADD_PLUGIN(qa_auth_client qa_auth_client.c
+  MODULE_ONLY)
+
+MYSQL_ADD_PLUGIN(mysql_clear_password clear_password_client.c
+  MODULE_ONLY)
diff --git a/plugin/auth_examples/clear_password_client.c b/plugin/auth_examples/clear_password_client.c
new file mode 100644
index 00000000000..31be263b869
--- /dev/null
+++ b/plugin/auth_examples/clear_password_client.c
@@ -0,0 +1,47 @@
+/* Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <mysql/client_plugin.h>
+#include <mysql.h>
+#include <string.h>
+
+/**
+  The main function of the mysql_clear_password authentication plugin.
+*/
+
+static int clear_password_auth_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
+{
+  int res;
+
+  /* send password in clear text */
+  res= vio->write_packet(vio, (const unsigned char *) mysql->passwd, 
+                              strlen(mysql->passwd) + 1);
+
+  return res ? CR_ERROR : CR_OK;
+}
+
+mysql_declare_client_plugin(AUTHENTICATION)
+  "mysql_clear_password",
+  "Georgi Kodinov",
+  "Clear password authentication plugin",
+  {0,1,0},
+  "GPL",
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  clear_password_auth_client
+mysql_end_client_plugin;
+
diff --git a/plugin/auth_examples/dialog_examples.c b/plugin/auth_examples/dialog_examples.c
new file mode 100644
index 00000000000..0d8897042c9
--- /dev/null
+++ b/plugin/auth_examples/dialog_examples.c
@@ -0,0 +1,154 @@
+/* Copyright (C) 2010 Sergei Golubchik and Monty Program Ab
+   Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; version 2 of the
+    License.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+/**
+  @file
+
+  examples for dialog client authentication plugin
+
+  Two examples are provided: two_questions server plugin, that asks
+  the password and an "Are you sure?" question with a reply "yes, of course".
+  It demonstrates the usage of "password" (input is hidden) and "ordinary"
+  (input can be echoed) questions, and how to mark the last question,
+  to avoid an extra roundtrip.
+
+  And three_attempts plugin that gives the user three attempts to enter
+  a correct password. It shows the situation when a number of questions
+  is not known in advance.
+*/
+
+#include <mysql/plugin_auth.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <mysql/auth_dialog_client.h>
+
+/********************* SERVER SIDE ****************************************/
+
+/**
+  dialog demo with two questions, one password and one, the last, ordinary.
+*/
+static int two_questions(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len;
+
+  /* send a password question */
+  if (vio->write_packet(vio,
+                        (const unsigned char *) PASSWORD_QUESTION "Password, please:",
+                        18))
+    return CR_ERROR;
+
+  /* read the answer */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  info->password_used= PASSWORD_USED_YES;
+
+  /* fail if the password is wrong */
+  if (strcmp((const char *) pkt, info->auth_string))
+    return CR_ERROR;
+
+  /* send the last, ordinary, question */
+  if (vio->write_packet(vio,
+                        (const unsigned char *) LAST_QUESTION "Are you sure ?",
+                        15))
+    return CR_ERROR;
+
+  /* read the answer */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  /* check the reply */
+  return strcmp((const char *) pkt, "yes, of course") ? CR_ERROR : CR_OK;
+}
+
+static struct st_mysql_auth two_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "dialog", /* requires dialog client plugin */
+  two_questions
+};
+
+/* dialog demo where the number of questions is not known in advance */
+static int three_attempts(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len, i;
+
+  for (i= 0; i < 3; i++)
+  {
+    /* send the prompt */
+    if (vio->write_packet(vio, 
+		(const unsigned char *) PASSWORD_QUESTION "Password, please:", 18))
+      return CR_ERROR;
+
+    /* read the password */
+    if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+      return CR_ERROR;
+
+    info->password_used= PASSWORD_USED_YES;
+
+    /*
+      finish, if the password is correct.
+      note, that we did not mark the prompt packet as "last"
+    */
+    if (strcmp((const char *) pkt, info->auth_string) == 0)
+      return CR_OK;
+  }
+
+  return CR_ERROR;
+}
+
+static struct st_mysql_auth three_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "dialog", /* requires dialog client plugin */
+  three_attempts 
+};
+
+mysql_declare_plugin(dialog)
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &two_handler,
+  "two_questions",
+  "Sergei Golubchik",
+  "Dialog plugin demo 1",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+},
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &three_handler,
+  "three_attempts",
+  "Sergei Golubchik",
+  "Dialog plugin demo 2",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+}
+mysql_declare_plugin_end;
+
diff --git a/plugin/auth_examples/qa_auth_client.c b/plugin/auth_examples/qa_auth_client.c
new file mode 100644
index 00000000000..a7ee2f83a39
--- /dev/null
+++ b/plugin/auth_examples/qa_auth_client.c
@@ -0,0 +1,117 @@
+/*  Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; version 2 of the
+    License.
+    
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include <my_global.h>
+#include <mysql/plugin_auth.h>
+#include <mysql/client_plugin.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/********************* CLIENT SIDE ***************************************/
+/*
+  client plugin used for testing the plugin API
+*/
+#include <mysql.h>
+
+/**
+  The main function of the test plugin.
+
+  Reads the prompt, check if the handshake is done and if the prompt is a
+  password request and returns the password. Otherwise return error.
+
+  @note
+   1. this plugin shows how a client authentication plugin
+      may read a MySQL protocol OK packet internally - which is important
+      where a number of packets is not known in advance.
+   2. the first byte of the prompt is special. it is not
+      shown to the user, but signals whether it is the last question
+      (prompt[0] & 1 == 1) or not last (prompt[0] & 1 == 0),
+      and whether the input is a password (not echoed).
+   3. the prompt is expected to be sent zero-terminated
+*/
+static int test_plugin_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
+{
+  unsigned char *pkt, cmd= 0;
+  int pkt_len, res;
+  char *reply;
+
+  do
+  {
+    /* read the prompt */
+    pkt_len= vio->read_packet(vio, &pkt);
+    if (pkt_len < 0)
+      return CR_ERROR;
+
+    if (pkt == 0)
+    {
+      /*
+        in mysql_change_user() the client sends the first packet, so
+        the first vio->read_packet() does nothing (pkt == 0).
+
+        We send the "password", assuming the client knows what its doing.
+        (in other words, the dialog plugin should be only set as a default
+        authentication plugin on the client if the first question
+        asks for a password - which will be sent in cleat text, by the way)
+      */
+      reply= mysql->passwd;
+    }
+    else
+    {
+      cmd= *pkt++;
+
+      /* is it MySQL protocol (0=OK or 254=need old password) packet ? */
+      if (cmd == 0 || cmd == 254)
+        return CR_OK_HANDSHAKE_COMPLETE; /* yes. we're done */
+
+      /*
+        asking for a password with an empty prompt means mysql->password
+        otherwise return an error
+      */
+      if ((cmd == LAST_PASSWORD[0] || cmd == PASSWORD_QUESTION[0]) && *pkt == 0)
+        reply= mysql->passwd;
+      else
+        return CR_ERROR;
+    }
+    if (!reply)
+      return CR_ERROR;
+    /* send the reply to the server */
+    res= vio->write_packet(vio, (const unsigned char *) reply, 
+                           strlen(reply) + 1);
+
+    if (res)
+      return CR_ERROR;
+
+    /* repeat unless it was the last question */
+  } while (cmd != LAST_QUESTION[0] && cmd != PASSWORD_QUESTION[0]);
+
+  /* the job of reading the ok/error packet is left to the server */
+  return CR_OK;
+}
+
+
+mysql_declare_client_plugin(AUTHENTICATION)
+  "qa_auth_client",
+  "Horst Hunger",
+  "Dialog Client Authentication Plugin",
+  {0,1,0},
+  "GPL",
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  test_plugin_client
+mysql_end_client_plugin;
diff --git a/plugin/auth_examples/qa_auth_interface.c b/plugin/auth_examples/qa_auth_interface.c
new file mode 100644
index 00000000000..a768995fbfd
--- /dev/null
+++ b/plugin/auth_examples/qa_auth_interface.c
@@ -0,0 +1,252 @@
+/*  Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; version 2 of the
+    License.
+    
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include <my_global.h>
+#include <mysql/plugin_auth.h>
+#include <mysql/client_plugin.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/********************* SERVER SIDE ****************************************/
+
+static int qa_auth_interface (MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len, err= CR_OK;
+
+  /* send a password question */
+  if (vio->write_packet(vio, (const unsigned char *) PASSWORD_QUESTION, 1))
+    return CR_ERROR;
+
+  /* read the answer */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  info->password_used= PASSWORD_USED_YES;
+
+  /* fail if the password is wrong */
+  if (strcmp((const char *) pkt, info->auth_string))
+    return CR_ERROR;
+
+/* Check the contens of components of info */
+  if (strcmp(info->user_name, "qa_test_1_user")== 0)
+  {
+    if (info->user_name_length != 14)
+       err= CR_ERROR;
+    if (strcmp(info->auth_string, "qa_test_1_dest"))
+       err= CR_ERROR;
+    if (info->auth_string_length != 14)
+       err= CR_ERROR;
+/* To be set by the plugin */
+//    if (strcmp(info->authenticated_as, "qa_test_1_user"))
+//       err= CR_ERROR;
+/* To be set by the plugin */
+//    if (strcmp(info->external_user, ""))
+//       err= CR_ERROR;
+    if (info->password_used != PASSWORD_USED_YES)
+       err= CR_ERROR;
+    if (strcmp(info->host_or_ip, "localhost"))
+       err= CR_ERROR;
+    if (info->host_or_ip_length != 9)
+       err= CR_ERROR;
+  }
+/* Assign values to the components of info even if not intended and watch the effect */
+  else if (strcmp(info->user_name, "qa_test_2_user")== 0)
+  {
+    /* Overwriting not intended, but with effect on USER() */
+     strcpy(info->user_name, "user_name");
+     info->user_name_length= 9;
+    /* Overwriting not intended, effect not visible */
+     strcpy((char *)info->auth_string, "auth_string");
+     info->auth_string_length= 11;
+    /* Assign with account for authorization, effect on CURRENT_USER() */
+     strcpy(info->authenticated_as, "authenticated_as");
+    /* Assign with an external account, effect on @@local.EXTERNAL_USER */
+     strcpy(info->external_user, "externaluser");
+    /* Overwriting will cause a core dump */
+//     strcpy(info->host_or_ip, "host_or_ip");
+//     info->host_or_ip_length= 10;
+  }
+/* Invalid, means too high values for length */
+  else if (strcmp(info->user_name, "qa_test_3_user")== 0)
+  {
+/* Original value is 14. Test runs also with higher value. Changes have no effect.*/
+     info->user_name_length= 28;
+     strcpy((char *)info->auth_string, "qa_test_3_dest");
+/* Original value is 14. Test runs also with higher value. Changes have no effect.*/
+     info->auth_string_length= 28;
+     strcpy(info->authenticated_as, info->auth_string);
+     strcpy(info->external_user, info->auth_string);
+  }
+/* Invalid, means too low values for length */
+  else if (strcmp(info->user_name, "qa_test_4_user")== 0)
+  {
+/* Original value is 14. Test runs also with lower value. Changes have no effect.*/
+     info->user_name_length= 8;
+     strcpy((char *)info->auth_string, "qa_test_4_dest");
+/* Original value is 14. Test runs also with lower value. Changes have no effect.*/
+     info->auth_string_length= 8;
+     strcpy(info->authenticated_as, info->auth_string);
+     strcpy(info->external_user, info->auth_string);
+  }
+/* Overwrite with empty values */
+  else if (strcmp(info->user_name, "qa_test_5_user")== 0)  
+  {
+/* This assignment has no effect.*/
+     strcpy(info->user_name, "");
+     info->user_name_length= 0;
+/* This assignment has no effect.*/
+     strcpy((char *)info->auth_string, "");
+     info->auth_string_length= 0;
+/* This assignment caused an error or an "empty" user */
+     strcpy(info->authenticated_as, "");
+/* This assignment has no effect.*/
+     strcpy(info->external_user, "");
+    /* Overwriting will cause a core dump */
+//     strcpy(info->host_or_ip, "");
+//     info->host_or_ip_length= 0;
+  }
+/* Set to 'root' */
+  else if (strcmp(info->user_name, "qa_test_6_user")== 0)
+  {
+     strcpy(info->authenticated_as, "root");
+  }
+  else
+  {
+     err= CR_ERROR;
+  }
+  return err;
+}
+
+static struct st_mysql_auth qa_auth_test_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "qa_auth_interface", /* requires test_plugin client's plugin */
+  qa_auth_interface
+};
+
+mysql_declare_plugin(test_plugin)
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &qa_auth_test_handler,
+  "qa_auth_interface",
+  "Horst Hunger",
+  "plugin API test plugin",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+}
+mysql_declare_plugin_end;
+
+/********************* CLIENT SIDE ***************************************/
+/*
+  client plugin used for testing the plugin API
+*/
+#include <mysql.h>
+
+/**
+  The main function of the test plugin.
+
+  Reads the prompt, check if the handshake is done and if the prompt is a
+  password request and returns the password. Otherwise return error.
+
+  @note
+   1. this plugin shows how a client authentication plugin
+      may read a MySQL protocol OK packet internally - which is important
+      where a number of packets is not known in advance.
+   2. the first byte of the prompt is special. it is not
+      shown to the user, but signals whether it is the last question
+      (prompt[0] & 1 == 1) or not last (prompt[0] & 1 == 0),
+      and whether the input is a password (not echoed).
+   3. the prompt is expected to be sent zero-terminated
+*/
+static int test_plugin_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
+{
+  unsigned char *pkt, cmd= 0;
+  int pkt_len, res;
+  char *reply;
+
+  do
+  {
+    /* read the prompt */
+    pkt_len= vio->read_packet(vio, &pkt);
+    if (pkt_len < 0)
+      return CR_ERROR;
+
+    if (pkt == 0)
+    {
+      /*
+        in mysql_change_user() the client sends the first packet, so
+        the first vio->read_packet() does nothing (pkt == 0).
+
+        We send the "password", assuming the client knows what its doing.
+        (in other words, the dialog plugin should be only set as a default
+        authentication plugin on the client if the first question
+        asks for a password - which will be sent in cleat text, by the way)
+      */
+      reply= mysql->passwd;
+    }
+    else
+    {
+      cmd= *pkt++;
+
+      /* is it MySQL protocol (0=OK or 254=need old password) packet ? */
+      if (cmd == 0 || cmd == 254)
+        return CR_OK_HANDSHAKE_COMPLETE; /* yes. we're done */
+
+      /*
+        asking for a password with an empty prompt means mysql->password
+        otherwise return an error
+      */
+      if ((cmd == LAST_PASSWORD[0] || cmd == PASSWORD_QUESTION[0]) && *pkt == 0)
+        reply= mysql->passwd;
+      else
+        return CR_ERROR;
+    }
+    if (!reply)
+      return CR_ERROR;
+    /* send the reply to the server */
+    res= vio->write_packet(vio, (const unsigned char *) reply, 
+                           strlen(reply) + 1);
+
+    if (res)
+      return CR_ERROR;
+
+    /* repeat unless it was the last question */
+  } while (cmd != LAST_QUESTION[0] && cmd != PASSWORD_QUESTION[0]);
+
+  /* the job of reading the ok/error packet is left to the server */
+  return CR_OK;
+}
+
+
+mysql_declare_client_plugin(AUTHENTICATION)
+  "qa_auth_interface",
+  "Horst Hunger",
+  "Dialog Client Authentication Plugin",
+  {0,1,0},
+  "GPL",
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  test_plugin_client
+mysql_end_client_plugin;
diff --git a/plugin/auth_examples/qa_auth_server.c b/plugin/auth_examples/qa_auth_server.c
new file mode 100644
index 00000000000..31cc4f08616
--- /dev/null
+++ b/plugin/auth_examples/qa_auth_server.c
@@ -0,0 +1,77 @@
+/*  Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; version 2 of the
+    License.
+    
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+#include <my_global.h>
+#include <mysql/plugin_auth.h>
+#include <mysql/client_plugin.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/********************* SERVER SIDE ****************************************/
+
+static int qa_auth_interface (MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len, err= CR_OK;
+
+  /* send a password question */
+  if (vio->write_packet(vio, (const unsigned char *) PASSWORD_QUESTION, 1))
+    return CR_ERROR;
+
+  /* read the answer */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  info->password_used= PASSWORD_USED_YES;
+
+  /* fail if the password is wrong */
+  if (strcmp((const char *) pkt, info->auth_string))
+    return CR_ERROR;
+
+/* Test of default_auth */
+  if (strcmp(info->user_name, "qa_test_11_user")== 0)
+  {
+     strcpy(info->authenticated_as, "qa_test_11_dest");
+  }
+  else
+     err= CR_ERROR;
+  return err;
+}
+
+static struct st_mysql_auth qa_auth_test_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "qa_auth_interface", /* requires test_plugin client's plugin */
+  qa_auth_interface
+};
+
+mysql_declare_plugin(test_plugin)
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &qa_auth_test_handler,
+  "qa_auth_server",
+  "Horst Hunger",
+  "plugin API test plugin",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+}
+mysql_declare_plugin_end;
diff --git a/plugin/auth_examples/test_plugin.c b/plugin/auth_examples/test_plugin.c
new file mode 100644
index 00000000000..da9ab51bb58
--- /dev/null
+++ b/plugin/auth_examples/test_plugin.c
@@ -0,0 +1,230 @@
+/*  Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+    
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; version 2 of the
+    License.
+    
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+    
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+/**
+  @file
+
+  Test driver for the mysql-test/t/plugin_auth.test
+
+  This is a set of test plugins used to test the external authentication 
+  implementation.
+  See the above test file for more details.
+  This test plugin is based on the dialog plugin example.
+*/
+
+#include <my_global.h>
+#include <mysql/plugin_auth.h>
+#include <mysql/client_plugin.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+/********************* SERVER SIDE ****************************************/
+
+/**
+  dialog test plugin mimicking the ordinary auth mechanism. Used to test the auth plugin API
+*/
+static int auth_test_plugin(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len;
+
+  /* send a password question */
+  if (vio->write_packet(vio, (const unsigned char *) PASSWORD_QUESTION, 1))
+    return CR_ERROR;
+
+  /* read the answer */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  info->password_used= PASSWORD_USED_YES;
+
+  /* fail if the password is wrong */
+  if (strcmp((const char *) pkt, info->auth_string))
+    return CR_ERROR;
+
+  /* copy auth string as a destination name to check it */
+  strcpy (info->authenticated_as, info->auth_string);
+
+  /* copy something into the external user name */
+  strcpy (info->external_user, info->auth_string);
+
+  return CR_OK;
+}
+
+static struct st_mysql_auth auth_test_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "auth_test_plugin", /* requires test_plugin client's plugin */
+  auth_test_plugin
+};
+
+/**
+  dialog test plugin mimicking the ordinary auth mechanism. Used to test the clear text plugin API
+*/
+static int auth_cleartext_plugin(MYSQL_PLUGIN_VIO *vio, 
+                                 MYSQL_SERVER_AUTH_INFO *info)
+{
+  unsigned char *pkt;
+  int pkt_len;
+
+  /* read the password */
+  if ((pkt_len= vio->read_packet(vio, &pkt)) < 0)
+    return CR_ERROR;
+
+  info->password_used= PASSWORD_USED_YES;
+
+  /* fail if the password is wrong */
+  if (strcmp((const char *) pkt, info->auth_string))
+    return CR_ERROR;
+
+  return CR_OK;
+}
+
+
+static struct st_mysql_auth auth_cleartext_handler=
+{
+  MYSQL_AUTHENTICATION_INTERFACE_VERSION,
+  "mysql_clear_password", /* requires the clear text plugin */
+  auth_cleartext_plugin
+};
+
+mysql_declare_plugin(test_plugin)
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &auth_test_handler,
+  "test_plugin_server",
+  "Georgi Kodinov",
+  "plugin API test plugin",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+},
+{
+  MYSQL_AUTHENTICATION_PLUGIN,
+  &auth_cleartext_handler,
+  "cleartext_plugin_server",
+  "Georgi Kodinov",
+  "cleartext plugin API test plugin",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  NULL,
+  NULL
+}
+mysql_declare_plugin_end;
+
+
+/********************* CLIENT SIDE ***************************************/
+/*
+  client plugin used for testing the plugin API
+*/
+#include <mysql.h>
+
+/**
+  The main function of the test plugin.
+
+  Reads the prompt, check if the handshake is done and if the prompt is a
+  password request and returns the password. Otherwise return error.
+
+  @note
+   1. this plugin shows how a client authentication plugin
+      may read a MySQL protocol OK packet internally - which is important
+      where a number of packets is not known in advance.
+   2. the first byte of the prompt is special. it is not
+      shown to the user, but signals whether it is the last question
+      (prompt[0] & 1 == 1) or not last (prompt[0] & 1 == 0),
+      and whether the input is a password (not echoed).
+   3. the prompt is expected to be sent zero-terminated
+*/
+static int test_plugin_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
+{
+  unsigned char *pkt, cmd= 0;
+  int pkt_len, res;
+  char *reply;
+
+  do
+  {
+    /* read the prompt */
+    pkt_len= vio->read_packet(vio, &pkt);
+    if (pkt_len < 0)
+      return CR_ERROR;
+
+    if (pkt == 0)
+    {
+      /*
+        in mysql_change_user() the client sends the first packet, so
+        the first vio->read_packet() does nothing (pkt == 0).
+
+        We send the "password", assuming the client knows what it's doing.
+        (in other words, the dialog plugin should be only set as a default
+        authentication plugin on the client if the first question
+        asks for a password - which will be sent in clear text, by the way)
+      */
+      reply= mysql->passwd;
+    }
+    else
+    {
+      cmd= *pkt++;
+
+      /* is it MySQL protocol (0=OK or 254=need old password) packet ? */
+      if (cmd == 0 || cmd == 254)
+        return CR_OK_HANDSHAKE_COMPLETE; /* yes. we're done */
+
+      /*
+        asking for a password with an empty prompt means mysql->password
+        otherwise return an error
+      */
+      if ((cmd == LAST_PASSWORD[0] || cmd == PASSWORD_QUESTION[0]) && *pkt == 0)
+        reply= mysql->passwd;
+      else
+        return CR_ERROR;
+    }
+    if (!reply)
+      return CR_ERROR;
+    /* send the reply to the server */
+    res= vio->write_packet(vio, (const unsigned char *) reply, 
+                           strlen(reply) + 1);
+
+    if (res)
+      return CR_ERROR;
+
+    /* repeat unless it was the last question */
+  } while (cmd != LAST_QUESTION[0] && cmd != PASSWORD_QUESTION[0]);
+
+  /* the job of reading the ok/error packet is left to the server */
+  return CR_OK;
+}
+
+
+mysql_declare_client_plugin(AUTHENTICATION)
+  "auth_test_plugin",
+  "Georgi Kodinov",
+  "Dialog Client Authentication Plugin",
+  {0,1,0},
+  "GPL",
+  NULL,
+  NULL,
+  NULL,
+  NULL,
+  test_plugin_client
+mysql_end_client_plugin;