New upstream version 3.2.1+dfsg1upstream/3.2.1+dfsg1

1 files changed, 360 insertions, 360 deletions

diff --git a/Plugins/DbSqliteWx/userauth.c b/Plugins/DbSqliteWx/userauth.c
index 6d776c3..b4a9e92 100644
--- a/Plugins/DbSqliteWx/userauth.c
+++ b/Plugins/DbSqliteWx/userauth.c
@@ -1,360 +1,360 @@
-/*

-** 2014-09-08

-**

-** The author disclaims copyright to this source code.  In place of

-** a legal notice, here is a blessing:

-**

-**    May you do good and not evil.

-**    May you find forgiveness for yourself and forgive others.

-**    May you share freely, never taking more than you give.

-**

-*************************************************************************

-**

-** This file contains the bulk of the implementation of the

-** user-authentication extension feature.  Some parts of the user-

-** authentication code are contained within the SQLite core (in the

-** src/ subdirectory of the main source code tree) but those parts

-** that could reasonable be separated out are moved into this file.

-**

-** To compile with the user-authentication feature, append this file to

-** end of an SQLite amalgamation, then add the SQLITE_USER_AUTHENTICATION

-** compile-time option.  See the user-auth.txt file in the same source

-** directory as this file for additional information.

-*/

-#ifdef SQLITE_USER_AUTHENTICATION

-#ifndef SQLITEINT_H

-# include "sqliteInt.h"

-#endif

-

-/*

-** Prepare an SQL statement for use by the user authentication logic.

-** Return a pointer to the prepared statement on success.  Return a

-** NULL pointer if there is an error of any kind.

-*/

-static wx_sqlite3_stmt *wx_sqlite3UserAuthPrepare(

-  wx_sqlite3 *db,

-  const char *zFormat,

-  ...

-){

-  wx_sqlite3_stmt *pStmt;

-  char *zSql;

-  int rc;

-  va_list ap;

-  int savedFlags = db->flags;

-

-  va_start(ap, zFormat);

-  zSql = wx_sqlite3_vmprintf(zFormat, ap);

-  va_end(ap);

-  if( zSql==0 ) return 0;

-  db->flags |= SQLITE_WriteSchema;

-  rc = wx_sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);

-  db->flags = savedFlags;

-  wx_sqlite3_free(zSql);

-  if( rc ){

-    wx_sqlite3_finalize(pStmt);

-    pStmt = 0;

-  }

-  return pStmt;

-}

-

-/*

-** Check to see if the sqlite_user table exists in database zDb.

-*/

-static int userTableExists(wx_sqlite3 *db, const char *zDb){

-  int rc;

-  wx_sqlite3_mutex_enter(db->mutex);

-  wx_sqlite3BtreeEnterAll(db);

-  if( db->init.busy==0 ){

-    char *zErr = 0;

-    wx_sqlite3Init(db, &zErr);

-    wx_sqlite3DbFree(db, zErr);

-  }

-  rc = wx_sqlite3FindTable(db, "sqlite_user", zDb)!=0;

-  wx_sqlite3BtreeLeaveAll(db);

-  wx_sqlite3_mutex_leave(db->mutex);

-  return rc;

-}

-

-/*

-** Check to see if database zDb has a "sqlite_user" table and if it does

-** whether that table can authenticate zUser with nPw,zPw.  Write one of

-** the UAUTH_* user authorization level codes into *peAuth and return a

-** result code.

-*/

-static int userAuthCheckLogin(

-  wx_sqlite3 *db,               /* The database connection to check */

-  const char *zDb,           /* Name of specific database to check */

-  u8 *peAuth                 /* OUT: One of UAUTH_* constants */

-){

-  wx_sqlite3_stmt *pStmt;

-  int rc;

-

-  *peAuth = UAUTH_Unknown;

-  if( !userTableExists(db, "main") ){

-    *peAuth = UAUTH_Admin;  /* No sqlite_user table.  Everybody is admin. */

-    return SQLITE_OK;

-  }

-  if( db->auth.zAuthUser==0 ){

-    *peAuth = UAUTH_Fail;

-    return SQLITE_OK;

-  }

-  pStmt = wx_sqlite3UserAuthPrepare(db,

-            "SELECT pw=sqlite_crypt(?1,pw), isAdmin FROM \"%w\".sqlite_user"

-            " WHERE uname=?2", zDb);

-  if( pStmt==0 ) return SQLITE_NOMEM;

-  wx_sqlite3_bind_blob(pStmt, 1, db->auth.zAuthPW, db->auth.nAuthPW,SQLITE_STATIC);

-  wx_sqlite3_bind_text(pStmt, 2, db->auth.zAuthUser, -1, SQLITE_STATIC);

-  rc = wx_sqlite3_step(pStmt);

-  if( rc==SQLITE_ROW && wx_sqlite3_column_int(pStmt,0) ){

-    *peAuth = wx_sqlite3_column_int(pStmt, 1) + UAUTH_User;

-  }else{

-    *peAuth = UAUTH_Fail;

-  }

-  return wx_sqlite3_finalize(pStmt);

-}

-int wx_sqlite3UserAuthCheckLogin(

-  wx_sqlite3 *db,               /* The database connection to check */

-  const char *zDb,           /* Name of specific database to check */

-  u8 *peAuth                 /* OUT: One of UAUTH_* constants */

-){

-  int rc;

-  u8 savedAuthLevel;

-  assert( zDb!=0 );

-  assert( peAuth!=0 );

-  savedAuthLevel = db->auth.authLevel;

-  db->auth.authLevel = UAUTH_Admin;

-  rc = userAuthCheckLogin(db, zDb, peAuth);

-  db->auth.authLevel = savedAuthLevel;

-  return rc;

-}

-

-/*

-** If the current authLevel is UAUTH_Unknown, the take actions to figure

-** out what authLevel should be

-*/

-void wx_sqlite3UserAuthInit(wx_sqlite3 *db){

-  if( db->auth.authLevel==UAUTH_Unknown ){

-    u8 authLevel = UAUTH_Fail;

-    wx_sqlite3UserAuthCheckLogin(db, "main", &authLevel);

-    db->auth.authLevel = authLevel;

-    if( authLevel<UAUTH_Admin ) db->flags &= ~SQLITE_WriteSchema;

-  }

-}

-

-/*

-** Implementation of the sqlite_crypt(X,Y) function.

-**

-** If Y is NULL then generate a new hash for password X and return that

-** hash.  If Y is not null, then generate a hash for password X using the

-** same salt as the previous hash Y and return the new hash.

-*/

-void wx_sqlite3CryptFunc(

-  wx_sqlite3_context *context,

-  int NotUsed,

-  wx_sqlite3_value **argv

-){

-  const char *zIn;

-  int nIn;

-  u8 *zData;

-  u8 *zOut;

-  char zSalt[16];

-  int nHash = 32;

-  zIn = wx_sqlite3_value_blob(argv[0]);

-  nIn = wx_sqlite3_value_bytes(argv[0]);

-  if( wx_sqlite3_value_type(argv[1])==SQLITE_BLOB

-   && wx_sqlite3_value_bytes(argv[1])==nHash+sizeof(zSalt)

-  ){

-    memcpy(zSalt, wx_sqlite3_value_blob(argv[1]), sizeof(zSalt));

-  }else{

-    wx_sqlite3_randomness(sizeof(zSalt), zSalt);

-  }

-  zData = wx_sqlite3_malloc( nIn+sizeof(zSalt) );

-  zOut = wx_sqlite3_malloc( nHash+sizeof(zSalt) );

-  if( zOut==0 ){

-    wx_sqlite3_result_error_nomem(context);

-  }else{

-    memcpy(zData, zSalt, sizeof(zSalt));

-    memcpy(zData+sizeof(zSalt), zIn, nIn);

-    memcpy(zOut, zSalt, sizeof(zSalt));

-    sha256(zData, (unsigned int) nIn+sizeof(zSalt), zOut+sizeof(zSalt));

-    wx_sqlite3_result_blob(context, zOut, nHash+sizeof(zSalt), wx_sqlite3_free);

-  }

-  if (zData != 0) wx_sqlite3_free(zData);

-}

-

-/*

-** If a database contains the SQLITE_USER table, then the

-** wx_sqlite3_user_authenticate() interface must be invoked with an

-** appropriate username and password prior to enable read and write

-** access to the database.

-**

-** Return SQLITE_OK on success or SQLITE_ERROR if the username/password

-** combination is incorrect or unknown.

-**

-** If the SQLITE_USER table is not present in the database file, then

-** this interface is a harmless no-op returnning SQLITE_OK.

-*/

-int wx_sqlite3_user_authenticate(

-  wx_sqlite3 *db,           /* The database connection */

-  const char *zUsername, /* Username */

-  const char *zPW,       /* Password or credentials */

-  int nPW                /* Number of bytes in aPW[] */

-){

-  int rc;

-  u8 authLevel = UAUTH_Fail;

-  db->auth.authLevel = UAUTH_Unknown;

-  wx_sqlite3_free(db->auth.zAuthUser);

-  wx_sqlite3_free(db->auth.zAuthPW);

-  memset(&db->auth, 0, sizeof(db->auth));

-  db->auth.zAuthUser = wx_sqlite3_mprintf("%s", zUsername);

-  if( db->auth.zAuthUser==0 ) return SQLITE_NOMEM;

-  db->auth.zAuthPW = wx_sqlite3_malloc( nPW+1 );

-  if( db->auth.zAuthPW==0 ) return SQLITE_NOMEM;

-  memcpy(db->auth.zAuthPW,zPW,nPW);

-  db->auth.nAuthPW = nPW;

-  rc = wx_sqlite3UserAuthCheckLogin(db, "main", &authLevel);

-  db->auth.authLevel = authLevel;

-  wx_sqlite3ExpirePreparedStatements(db);

-  if( rc ){

-    return rc;           /* OOM error, I/O error, etc. */

-  }

-  if( authLevel<UAUTH_User ){

-    return SQLITE_AUTH;  /* Incorrect username and/or password */

-  }

-  return SQLITE_OK;      /* Successful login */

-}

-

-/*

-** The wx_sqlite3_user_add() interface can be used (by an admin user only)

-** to create a new user.  When called on a no-authentication-required

-** database, this routine converts the database into an authentication-

-** required database, automatically makes the added user an

-** administrator, and logs in the current connection as that user.

-** The wx_sqlite3_user_add() interface only works for the "main" database, not

-** for any ATTACH-ed databases.  Any call to wx_sqlite3_user_add() by a

-** non-admin user results in an error.

-*/

-int wx_sqlite3_user_add(

-  wx_sqlite3 *db,           /* Database connection */

-  const char *zUsername, /* Username to be added */

-  const char *aPW,       /* Password or credentials */

-  int nPW,               /* Number of bytes in aPW[] */

-  int isAdmin            /* True to give new user admin privilege */

-){

-  wx_sqlite3_stmt *pStmt;

-  int rc;

-  wx_sqlite3UserAuthInit(db);

-  if( db->auth.authLevel<UAUTH_Admin ) return SQLITE_AUTH;

-  if( !userTableExists(db, "main") ){

-    if( !isAdmin ) return SQLITE_AUTH;

-    pStmt = wx_sqlite3UserAuthPrepare(db, 

-              "CREATE TABLE sqlite_user(\n"

-              "  uname TEXT PRIMARY KEY,\n"

-              "  isAdmin BOOLEAN,\n"

-              "  pw BLOB\n"

-              ") WITHOUT ROWID;");

-    if( pStmt==0 ) return SQLITE_NOMEM;

-    wx_sqlite3_step(pStmt);

-    rc = wx_sqlite3_finalize(pStmt);

-    if( rc ) return rc;

-  }

-  pStmt = wx_sqlite3UserAuthPrepare(db, 

-            "INSERT INTO sqlite_user(uname,isAdmin,pw)"

-            " VALUES(%Q,%d,sqlite_crypt(?1,NULL))",

-            zUsername, isAdmin!=0);

-  if( pStmt==0 ) return SQLITE_NOMEM;

-  wx_sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);

-  wx_sqlite3_step(pStmt);

-  rc = wx_sqlite3_finalize(pStmt);

-  if( rc ) return rc;

-  if( db->auth.zAuthUser==0 ){

-    assert( isAdmin!=0 );

-    wx_sqlite3_user_authenticate(db, zUsername, aPW, nPW);

-  }

-  return SQLITE_OK;

-}

-

-/*

-** The wx_sqlite3_user_change() interface can be used to change a users

-** login credentials or admin privilege.  Any user can change their own

-** login credentials.  Only an admin user can change another users login

-** credentials or admin privilege setting.  No user may change their own 

-** admin privilege setting.

-*/

-int wx_sqlite3_user_change(

-  wx_sqlite3 *db,           /* Database connection */

-  const char *zUsername, /* Username to change */

-  const char *aPW,       /* Modified password or credentials */

-  int nPW,               /* Number of bytes in aPW[] */

-  int isAdmin            /* Modified admin privilege for the user */

-){

-  wx_sqlite3_stmt *pStmt;

-  int rc;

-  u8 authLevel;

-

-  authLevel = db->auth.authLevel;

-  if( authLevel<UAUTH_User ){

-    /* Must be logged in to make a change */

-    return SQLITE_AUTH;

-  }

-  if( strcmp(db->auth.zAuthUser, zUsername)!=0 ){

-    if( db->auth.authLevel<UAUTH_Admin ){

-      /* Must be an administrator to change a different user */

-      return SQLITE_AUTH;

-    }

-  }else if( isAdmin!=(authLevel==UAUTH_Admin) ){

-    /* Cannot change the isAdmin setting for self */

-    return SQLITE_AUTH;

-  }

-  db->auth.authLevel = UAUTH_Admin;

-  if( !userTableExists(db, "main") ){

-    /* This routine is a no-op if the user to be modified does not exist */

-  }else{

-    pStmt = wx_sqlite3UserAuthPrepare(db,

-              "UPDATE sqlite_user SET isAdmin=%d, pw=sqlite_crypt(?1,NULL)"

-              " WHERE uname=%Q", isAdmin, zUsername);

-    if( pStmt==0 ){

-      rc = SQLITE_NOMEM;

-    }else{

-      wx_sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);

-      wx_sqlite3_step(pStmt);

-      rc = wx_sqlite3_finalize(pStmt);

-    }

-  }

-  db->auth.authLevel = authLevel;

-  return rc;

-}

-

-/*

-** The wx_sqlite3_user_delete() interface can be used (by an admin user only)

-** to delete a user.  The currently logged-in user cannot be deleted,

-** which guarantees that there is always an admin user and hence that

-** the database cannot be converted into a no-authentication-required

-** database.

-*/

-int wx_sqlite3_user_delete(

-  wx_sqlite3 *db,           /* Database connection */

-  const char *zUsername  /* Username to remove */

-){

-  wx_sqlite3_stmt *pStmt;

-  if( db->auth.authLevel<UAUTH_Admin ){

-    /* Must be an administrator to delete a user */

-    return SQLITE_AUTH;

-  }

-  if( strcmp(db->auth.zAuthUser, zUsername)==0 ){

-    /* Cannot delete self */

-    return SQLITE_AUTH;

-  }

-  if( !userTableExists(db, "main") ){

-    /* This routine is a no-op if the user to be deleted does not exist */

-    return SQLITE_OK;

-  }

-  pStmt = wx_sqlite3UserAuthPrepare(db,

-              "DELETE FROM sqlite_user WHERE uname=%Q", zUsername);

-  if( pStmt==0 ) return SQLITE_NOMEM;

-  wx_sqlite3_step(pStmt);

-  return wx_sqlite3_finalize(pStmt);

-}

-

-#endif /* SQLITE_USER_AUTHENTICATION */

-

+/*
+** 2014-09-08
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains the bulk of the implementation of the
+** user-authentication extension feature.  Some parts of the user-
+** authentication code are contained within the SQLite core (in the
+** src/ subdirectory of the main source code tree) but those parts
+** that could reasonable be separated out are moved into this file.
+**
+** To compile with the user-authentication feature, append this file to
+** end of an SQLite amalgamation, then add the SQLITE_USER_AUTHENTICATION
+** compile-time option.  See the user-auth.txt file in the same source
+** directory as this file for additional information.
+*/
+#ifdef SQLITE_USER_AUTHENTICATION
+#ifndef SQLITEINT_H
+# include "sqliteInt.h"
+#endif
+
+/*
+** Prepare an SQL statement for use by the user authentication logic.
+** Return a pointer to the prepared statement on success.  Return a
+** NULL pointer if there is an error of any kind.
+*/
+static wx_sqlite3_stmt *wx_sqlite3UserAuthPrepare(
+  wx_sqlite3 *db,
+  const char *zFormat,
+  ...
+){
+  wx_sqlite3_stmt *pStmt;
+  char *zSql;
+  int rc;
+  va_list ap;
+  int savedFlags = db->flags;
+
+  va_start(ap, zFormat);
+  zSql = wx_sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  if( zSql==0 ) return 0;
+  db->flags |= SQLITE_WriteSchema;
+  rc = wx_sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+  db->flags = savedFlags;
+  wx_sqlite3_free(zSql);
+  if( rc ){
+    wx_sqlite3_finalize(pStmt);
+    pStmt = 0;
+  }
+  return pStmt;
+}
+
+/*
+** Check to see if the sqlite_user table exists in database zDb.
+*/
+static int userTableExists(wx_sqlite3 *db, const char *zDb){
+  int rc;
+  wx_sqlite3_mutex_enter(db->mutex);
+  wx_sqlite3BtreeEnterAll(db);
+  if( db->init.busy==0 ){
+    char *zErr = 0;
+    wx_sqlite3Init(db, &zErr);
+    wx_sqlite3DbFree(db, zErr);
+  }
+  rc = wx_sqlite3FindTable(db, "sqlite_user", zDb)!=0;
+  wx_sqlite3BtreeLeaveAll(db);
+  wx_sqlite3_mutex_leave(db->mutex);
+  return rc;
+}
+
+/*
+** Check to see if database zDb has a "sqlite_user" table and if it does
+** whether that table can authenticate zUser with nPw,zPw.  Write one of
+** the UAUTH_* user authorization level codes into *peAuth and return a
+** result code.
+*/
+static int userAuthCheckLogin(
+  wx_sqlite3 *db,               /* The database connection to check */
+  const char *zDb,           /* Name of specific database to check */
+  u8 *peAuth                 /* OUT: One of UAUTH_* constants */
+){
+  wx_sqlite3_stmt *pStmt;
+  int rc;
+
+  *peAuth = UAUTH_Unknown;
+  if( !userTableExists(db, "main") ){
+    *peAuth = UAUTH_Admin;  /* No sqlite_user table.  Everybody is admin. */
+    return SQLITE_OK;
+  }
+  if( db->auth.zAuthUser==0 ){
+    *peAuth = UAUTH_Fail;
+    return SQLITE_OK;
+  }
+  pStmt = wx_sqlite3UserAuthPrepare(db,
+            "SELECT pw=sqlite_crypt(?1,pw), isAdmin FROM \"%w\".sqlite_user"
+            " WHERE uname=?2", zDb);
+  if( pStmt==0 ) return SQLITE_NOMEM;
+  wx_sqlite3_bind_blob(pStmt, 1, db->auth.zAuthPW, db->auth.nAuthPW,SQLITE_STATIC);
+  wx_sqlite3_bind_text(pStmt, 2, db->auth.zAuthUser, -1, SQLITE_STATIC);
+  rc = wx_sqlite3_step(pStmt);
+  if( rc==SQLITE_ROW && wx_sqlite3_column_int(pStmt,0) ){
+    *peAuth = wx_sqlite3_column_int(pStmt, 1) + UAUTH_User;
+  }else{
+    *peAuth = UAUTH_Fail;
+  }
+  return wx_sqlite3_finalize(pStmt);
+}
+int wx_sqlite3UserAuthCheckLogin(
+  wx_sqlite3 *db,               /* The database connection to check */
+  const char *zDb,           /* Name of specific database to check */
+  u8 *peAuth                 /* OUT: One of UAUTH_* constants */
+){
+  int rc;
+  u8 savedAuthLevel;
+  assert( zDb!=0 );
+  assert( peAuth!=0 );
+  savedAuthLevel = db->auth.authLevel;
+  db->auth.authLevel = UAUTH_Admin;
+  rc = userAuthCheckLogin(db, zDb, peAuth);
+  db->auth.authLevel = savedAuthLevel;
+  return rc;
+}
+
+/*
+** If the current authLevel is UAUTH_Unknown, the take actions to figure
+** out what authLevel should be
+*/
+void wx_sqlite3UserAuthInit(wx_sqlite3 *db){
+  if( db->auth.authLevel==UAUTH_Unknown ){
+    u8 authLevel = UAUTH_Fail;
+    wx_sqlite3UserAuthCheckLogin(db, "main", &authLevel);
+    db->auth.authLevel = authLevel;
+    if( authLevel<UAUTH_Admin ) db->flags &= ~SQLITE_WriteSchema;
+  }
+}
+
+/*
+** Implementation of the sqlite_crypt(X,Y) function.
+**
+** If Y is NULL then generate a new hash for password X and return that
+** hash.  If Y is not null, then generate a hash for password X using the
+** same salt as the previous hash Y and return the new hash.
+*/
+void wx_sqlite3CryptFunc(
+  wx_sqlite3_context *context,
+  int NotUsed,
+  wx_sqlite3_value **argv
+){
+  const char *zIn;
+  int nIn;
+  u8 *zData;
+  u8 *zOut;
+  char zSalt[16];
+  int nHash = 32;
+  zIn = wx_sqlite3_value_blob(argv[0]);
+  nIn = wx_sqlite3_value_bytes(argv[0]);
+  if( wx_sqlite3_value_type(argv[1])==SQLITE_BLOB
+   && wx_sqlite3_value_bytes(argv[1])==nHash+sizeof(zSalt)
+  ){
+    memcpy(zSalt, wx_sqlite3_value_blob(argv[1]), sizeof(zSalt));
+  }else{
+    wx_sqlite3_randomness(sizeof(zSalt), zSalt);
+  }
+  zData = wx_sqlite3_malloc( nIn+sizeof(zSalt) );
+  zOut = wx_sqlite3_malloc( nHash+sizeof(zSalt) );
+  if( zOut==0 ){
+    wx_sqlite3_result_error_nomem(context);
+  }else{
+    memcpy(zData, zSalt, sizeof(zSalt));
+    memcpy(zData+sizeof(zSalt), zIn, nIn);
+    memcpy(zOut, zSalt, sizeof(zSalt));
+    sha256(zData, (unsigned int) nIn+sizeof(zSalt), zOut+sizeof(zSalt));
+    wx_sqlite3_result_blob(context, zOut, nHash+sizeof(zSalt), wx_sqlite3_free);
+  }
+  if (zData != 0) wx_sqlite3_free(zData);
+}
+
+/*
+** If a database contains the SQLITE_USER table, then the
+** wx_sqlite3_user_authenticate() interface must be invoked with an
+** appropriate username and password prior to enable read and write
+** access to the database.
+**
+** Return SQLITE_OK on success or SQLITE_ERROR if the username/password
+** combination is incorrect or unknown.
+**
+** If the SQLITE_USER table is not present in the database file, then
+** this interface is a harmless no-op returnning SQLITE_OK.
+*/
+int wx_sqlite3_user_authenticate(
+  wx_sqlite3 *db,           /* The database connection */
+  const char *zUsername, /* Username */
+  const char *zPW,       /* Password or credentials */
+  int nPW                /* Number of bytes in aPW[] */
+){
+  int rc;
+  u8 authLevel = UAUTH_Fail;
+  db->auth.authLevel = UAUTH_Unknown;
+  wx_sqlite3_free(db->auth.zAuthUser);
+  wx_sqlite3_free(db->auth.zAuthPW);
+  memset(&db->auth, 0, sizeof(db->auth));
+  db->auth.zAuthUser = wx_sqlite3_mprintf("%s", zUsername);
+  if( db->auth.zAuthUser==0 ) return SQLITE_NOMEM;
+  db->auth.zAuthPW = wx_sqlite3_malloc( nPW+1 );
+  if( db->auth.zAuthPW==0 ) return SQLITE_NOMEM;
+  memcpy(db->auth.zAuthPW,zPW,nPW);
+  db->auth.nAuthPW = nPW;
+  rc = wx_sqlite3UserAuthCheckLogin(db, "main", &authLevel);
+  db->auth.authLevel = authLevel;
+  wx_sqlite3ExpirePreparedStatements(db);
+  if( rc ){
+    return rc;           /* OOM error, I/O error, etc. */
+  }
+  if( authLevel<UAUTH_User ){
+    return SQLITE_AUTH;  /* Incorrect username and/or password */
+  }
+  return SQLITE_OK;      /* Successful login */
+}
+
+/*
+** The wx_sqlite3_user_add() interface can be used (by an admin user only)
+** to create a new user.  When called on a no-authentication-required
+** database, this routine converts the database into an authentication-
+** required database, automatically makes the added user an
+** administrator, and logs in the current connection as that user.
+** The wx_sqlite3_user_add() interface only works for the "main" database, not
+** for any ATTACH-ed databases.  Any call to wx_sqlite3_user_add() by a
+** non-admin user results in an error.
+*/
+int wx_sqlite3_user_add(
+  wx_sqlite3 *db,           /* Database connection */
+  const char *zUsername, /* Username to be added */
+  const char *aPW,       /* Password or credentials */
+  int nPW,               /* Number of bytes in aPW[] */
+  int isAdmin            /* True to give new user admin privilege */
+){
+  wx_sqlite3_stmt *pStmt;
+  int rc;
+  wx_sqlite3UserAuthInit(db);
+  if( db->auth.authLevel<UAUTH_Admin ) return SQLITE_AUTH;
+  if( !userTableExists(db, "main") ){
+    if( !isAdmin ) return SQLITE_AUTH;
+    pStmt = wx_sqlite3UserAuthPrepare(db, 
+              "CREATE TABLE sqlite_user(\n"
+              "  uname TEXT PRIMARY KEY,\n"
+              "  isAdmin BOOLEAN,\n"
+              "  pw BLOB\n"
+              ") WITHOUT ROWID;");
+    if( pStmt==0 ) return SQLITE_NOMEM;
+    wx_sqlite3_step(pStmt);
+    rc = wx_sqlite3_finalize(pStmt);
+    if( rc ) return rc;
+  }
+  pStmt = wx_sqlite3UserAuthPrepare(db, 
+            "INSERT INTO sqlite_user(uname,isAdmin,pw)"
+            " VALUES(%Q,%d,sqlite_crypt(?1,NULL))",
+            zUsername, isAdmin!=0);
+  if( pStmt==0 ) return SQLITE_NOMEM;
+  wx_sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);
+  wx_sqlite3_step(pStmt);
+  rc = wx_sqlite3_finalize(pStmt);
+  if( rc ) return rc;
+  if( db->auth.zAuthUser==0 ){
+    assert( isAdmin!=0 );
+    wx_sqlite3_user_authenticate(db, zUsername, aPW, nPW);
+  }
+  return SQLITE_OK;
+}
+
+/*
+** The wx_sqlite3_user_change() interface can be used to change a users
+** login credentials or admin privilege.  Any user can change their own
+** login credentials.  Only an admin user can change another users login
+** credentials or admin privilege setting.  No user may change their own 
+** admin privilege setting.
+*/
+int wx_sqlite3_user_change(
+  wx_sqlite3 *db,           /* Database connection */
+  const char *zUsername, /* Username to change */
+  const char *aPW,       /* Modified password or credentials */
+  int nPW,               /* Number of bytes in aPW[] */
+  int isAdmin            /* Modified admin privilege for the user */
+){
+  wx_sqlite3_stmt *pStmt;
+  int rc;
+  u8 authLevel;
+
+  authLevel = db->auth.authLevel;
+  if( authLevel<UAUTH_User ){
+    /* Must be logged in to make a change */
+    return SQLITE_AUTH;
+  }
+  if( strcmp(db->auth.zAuthUser, zUsername)!=0 ){
+    if( db->auth.authLevel<UAUTH_Admin ){
+      /* Must be an administrator to change a different user */
+      return SQLITE_AUTH;
+    }
+  }else if( isAdmin!=(authLevel==UAUTH_Admin) ){
+    /* Cannot change the isAdmin setting for self */
+    return SQLITE_AUTH;
+  }
+  db->auth.authLevel = UAUTH_Admin;
+  if( !userTableExists(db, "main") ){
+    /* This routine is a no-op if the user to be modified does not exist */
+  }else{
+    pStmt = wx_sqlite3UserAuthPrepare(db,
+              "UPDATE sqlite_user SET isAdmin=%d, pw=sqlite_crypt(?1,NULL)"
+              " WHERE uname=%Q", isAdmin, zUsername);
+    if( pStmt==0 ){
+      rc = SQLITE_NOMEM;
+    }else{
+      wx_sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC);
+      wx_sqlite3_step(pStmt);
+      rc = wx_sqlite3_finalize(pStmt);
+    }
+  }
+  db->auth.authLevel = authLevel;
+  return rc;
+}
+
+/*
+** The wx_sqlite3_user_delete() interface can be used (by an admin user only)
+** to delete a user.  The currently logged-in user cannot be deleted,
+** which guarantees that there is always an admin user and hence that
+** the database cannot be converted into a no-authentication-required
+** database.
+*/
+int wx_sqlite3_user_delete(
+  wx_sqlite3 *db,           /* Database connection */
+  const char *zUsername  /* Username to remove */
+){
+  wx_sqlite3_stmt *pStmt;
+  if( db->auth.authLevel<UAUTH_Admin ){
+    /* Must be an administrator to delete a user */
+    return SQLITE_AUTH;
+  }
+  if( strcmp(db->auth.zAuthUser, zUsername)==0 ){
+    /* Cannot delete self */
+    return SQLITE_AUTH;
+  }
+  if( !userTableExists(db, "main") ){
+    /* This routine is a no-op if the user to be deleted does not exist */
+    return SQLITE_OK;
+  }
+  pStmt = wx_sqlite3UserAuthPrepare(db,
+              "DELETE FROM sqlite_user WHERE uname=%Q", zUsername);
+  if( pStmt==0 ) return SQLITE_NOMEM;
+  wx_sqlite3_step(pStmt);
+  return wx_sqlite3_finalize(pStmt);
+}
+
+#endif /* SQLITE_USER_AUTHENTICATION */
+