diff options
Diffstat (limited to 'ext/userauth/userauth.c')
| -rw-r--r-- | ext/userauth/userauth.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/ext/userauth/userauth.c b/ext/userauth/userauth.c new file mode 100644 index 0000000..fa70851 --- /dev/null +++ b/ext/userauth/userauth.c @@ -0,0 +1,355 @@ +/* +** 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 sqlite3_stmt *sqlite3UserAuthPrepare( + sqlite3 *db, + const char *zFormat, + ... +){ + sqlite3_stmt *pStmt; + char *zSql; + int rc; + va_list ap; + u64 savedFlags = db->flags; + + va_start(ap, zFormat); + zSql = sqlite3_vmprintf(zFormat, ap); + va_end(ap); + if( zSql==0 ) return 0; + db->flags |= SQLITE_WriteSchema; + rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0); + db->flags = savedFlags; + sqlite3_free(zSql); + if( rc ){ + sqlite3_finalize(pStmt); + pStmt = 0; + } + return pStmt; +} + +/* +** Check to see if the sqlite_user table exists in database zDb. +*/ +static int userTableExists(sqlite3 *db, const char *zDb){ + int rc; + sqlite3_mutex_enter(db->mutex); + sqlite3BtreeEnterAll(db); + if( db->init.busy==0 ){ + char *zErr = 0; + sqlite3Init(db, &zErr); + sqlite3DbFree(db, zErr); + } + rc = sqlite3FindTable(db, "sqlite_user", zDb)!=0; + sqlite3BtreeLeaveAll(db); + 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( + sqlite3 *db, /* The database connection to check */ + const char *zDb, /* Name of specific database to check */ + u8 *peAuth /* OUT: One of UAUTH_* constants */ +){ + 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 = sqlite3UserAuthPrepare(db, + "SELECT pw=sqlite_crypt(?1,pw), isAdmin FROM \"%w\".sqlite_user" + " WHERE uname=?2", zDb); + if( pStmt==0 ) return SQLITE_NOMEM; + sqlite3_bind_blob(pStmt, 1, db->auth.zAuthPW, db->auth.nAuthPW,SQLITE_STATIC); + sqlite3_bind_text(pStmt, 2, db->auth.zAuthUser, -1, SQLITE_STATIC); + rc = sqlite3_step(pStmt); + if( rc==SQLITE_ROW && sqlite3_column_int(pStmt,0) ){ + *peAuth = sqlite3_column_int(pStmt, 1) + UAUTH_User; + }else{ + *peAuth = UAUTH_Fail; + } + return sqlite3_finalize(pStmt); +} +int sqlite3UserAuthCheckLogin( + 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 sqlite3UserAuthInit(sqlite3 *db){ + if( db->auth.authLevel==UAUTH_Unknown ){ + u8 authLevel = UAUTH_Fail; + 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 sqlite3CryptFunc( + sqlite3_context *context, + int NotUsed, + sqlite3_value **argv +){ + const char *zIn; + int nIn, ii; + u8 *zOut; + char zSalt[8]; + zIn = sqlite3_value_blob(argv[0]); + nIn = sqlite3_value_bytes(argv[0]); + if( sqlite3_value_type(argv[1])==SQLITE_BLOB + && sqlite3_value_bytes(argv[1])==nIn+sizeof(zSalt) + ){ + memcpy(zSalt, sqlite3_value_blob(argv[1]), sizeof(zSalt)); + }else{ + sqlite3_randomness(sizeof(zSalt), zSalt); + } + zOut = sqlite3_malloc( nIn+sizeof(zSalt) ); + if( zOut==0 ){ + sqlite3_result_error_nomem(context); + }else{ + memcpy(zOut, zSalt, sizeof(zSalt)); + for(ii=0; ii<nIn; ii++){ + zOut[ii+sizeof(zSalt)] = zIn[ii]^zSalt[ii&0x7]; + } + sqlite3_result_blob(context, zOut, nIn+sizeof(zSalt), sqlite3_free); + } +} + +/* +** If a database contains the SQLITE_USER table, then the +** 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 sqlite3_user_authenticate( + 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; + sqlite3_free(db->auth.zAuthUser); + sqlite3_free(db->auth.zAuthPW); + memset(&db->auth, 0, sizeof(db->auth)); + db->auth.zAuthUser = sqlite3_mprintf("%s", zUsername); + if( db->auth.zAuthUser==0 ) return SQLITE_NOMEM; + db->auth.zAuthPW = sqlite3_malloc( nPW+1 ); + if( db->auth.zAuthPW==0 ) return SQLITE_NOMEM; + memcpy(db->auth.zAuthPW,zPW,nPW); + db->auth.nAuthPW = nPW; + rc = sqlite3UserAuthCheckLogin(db, "main", &authLevel); + db->auth.authLevel = authLevel; + sqlite3ExpirePreparedStatements(db, 0); + 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 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 sqlite3_user_add() interface only works for the "main" database, not +** for any ATTACH-ed databases. Any call to sqlite3_user_add() by a +** non-admin user results in an error. +*/ +int sqlite3_user_add( + 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 */ +){ + sqlite3_stmt *pStmt; + int rc; + sqlite3UserAuthInit(db); + if( db->auth.authLevel<UAUTH_Admin ) return SQLITE_AUTH; + if( !userTableExists(db, "main") ){ + if( !isAdmin ) return SQLITE_AUTH; + pStmt = 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; + sqlite3_step(pStmt); + rc = sqlite3_finalize(pStmt); + if( rc ) return rc; + } + pStmt = 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; + sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC); + sqlite3_step(pStmt); + rc = sqlite3_finalize(pStmt); + if( rc ) return rc; + if( db->auth.zAuthUser==0 ){ + assert( isAdmin!=0 ); + sqlite3_user_authenticate(db, zUsername, aPW, nPW); + } + return SQLITE_OK; +} + +/* +** The 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 sqlite3_user_change( + 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 */ +){ + 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 = 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{ + sqlite3_bind_blob(pStmt, 1, aPW, nPW, SQLITE_STATIC); + sqlite3_step(pStmt); + rc = sqlite3_finalize(pStmt); + } + } + db->auth.authLevel = authLevel; + return rc; +} + +/* +** The 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 sqlite3_user_delete( + sqlite3 *db, /* Database connection */ + const char *zUsername /* Username to remove */ +){ + 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 = sqlite3UserAuthPrepare(db, + "DELETE FROM sqlite_user WHERE uname=%Q", zUsername); + if( pStmt==0 ) return SQLITE_NOMEM; + sqlite3_step(pStmt); + return sqlite3_finalize(pStmt); +} + +#endif /* SQLITE_USER_AUTHENTICATION */ |