From e30f9ffa3a5542b36b683f75e443b0598b33813b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Grzegorz=20Marsza=C5=82ek?= <gm@itbce.com>
Date: Sat, 25 Aug 2018 20:25:16 +0200
Subject: [PATCH] implementation of set_authorizer interface

---
 callback.go     |  6 ++++++
 sqlite3.go      | 56 ++++++++++++++++++++++++++++++++++++++++++++++---
 sqlite3_test.go | 41 ++++++++++++++++++++++++++++++++++++
 3 files changed, 100 insertions(+), 3 deletions(-)

diff --git a/callback.go b/callback.go
index 5a735c0..2c68973 100644
--- a/callback.go
+++ b/callback.go
@@ -77,6 +77,12 @@ func updateHookTrampoline(handle uintptr, op int, db *C.char, table *C.char, row
 	callback(op, C.GoString(db), C.GoString(table), rowid)
 }
 
+//export authorizerTrampoline
+func authorizerTrampoline(handle uintptr, op int, arg1 *C.char, arg2 *C.char, arg3 *C.char) int {
+	callback := lookupHandle(handle).(func(int, string, string, string) int)
+	return callback(op, C.GoString(arg1), C.GoString(arg2), C.GoString(arg3))
+}
+
 // Use handles to avoid passing Go pointers to C.
 
 type handleVal struct {
diff --git a/sqlite3.go b/sqlite3.go
index b97647b..0dc9b04 100644
--- a/sqlite3.go
+++ b/sqlite3.go
@@ -119,6 +119,8 @@ int commitHookTrampoline(void*);
 void rollbackHookTrampoline(void*);
 void updateHookTrampoline(void*, int, char*, char*, sqlite3_int64);
 
+int authorizerTrampoline(void*, int, char*, char*, char*, char*);
+
 #ifdef SQLITE_LIMIT_WORKER_THREADS
 # define _SQLITE_HAS_LIMIT
 # define SQLITE_LIMIT_LENGTH                    0
@@ -200,9 +202,43 @@ func Version() (libVersion string, libVersionNumber int, sourceID string) {
 }
 
 const (
-	SQLITE_DELETE = C.SQLITE_DELETE
-	SQLITE_INSERT = C.SQLITE_INSERT
-	SQLITE_UPDATE = C.SQLITE_UPDATE
+	SQLITE_OK                  = C.SQLITE_OK
+	SQLITE_IGNORE              = C.SQLITE_IGNORE
+	SQLITE_DENY                = C.SQLITE_DENY
+	SQLITE_CREATE_INDEX        = C.SQLITE_CREATE_INDEX
+	SQLITE_CREATE_TABLE        = C.SQLITE_CREATE_TABLE
+	SQLITE_CREATE_TEMP_INDEX   = C.SQLITE_CREATE_TEMP_INDEX
+	SQLITE_CREATE_TEMP_TABLE   = C.SQLITE_CREATE_TEMP_TABLE
+	SQLITE_CREATE_TEMP_TRIGGER = C.SQLITE_CREATE_TEMP_TRIGGER
+	SQLITE_CREATE_TEMP_VIEW    = C.SQLITE_CREATE_TEMP_VIEW
+	SQLITE_CREATE_TRIGGER      = C.SQLITE_CREATE_TRIGGER
+	SQLITE_CREATE_VIEW         = C.SQLITE_CREATE_VIEW
+	SQLITE_DELETE              = C.SQLITE_DELETE
+	SQLITE_DROP_INDEX          = C.SQLITE_DROP_INDEX
+	SQLITE_DROP_TABLE          = C.SQLITE_DROP_TABLE
+	SQLITE_DROP_TEMP_INDEX     = C.SQLITE_DROP_TEMP_INDEX
+	SQLITE_DROP_TEMP_TABLE     = C.SQLITE_DROP_TEMP_TABLE
+	SQLITE_DROP_TEMP_TRIGGER   = C.SQLITE_DROP_TEMP_TRIGGER
+	SQLITE_DROP_TEMP_VIEW      = C.SQLITE_DROP_TEMP_VIEW
+	SQLITE_DROP_TRIGGER        = C.SQLITE_DROP_TRIGGER
+	SQLITE_DROP_VIEW           = C.SQLITE_DROP_VIEW
+	SQLITE_INSERT              = C.SQLITE_INSERT
+	SQLITE_PRAGMA              = C.SQLITE_PRAGMA
+	SQLITE_READ                = C.SQLITE_READ
+	SQLITE_SELECT              = C.SQLITE_SELECT
+	SQLITE_TRANSACTION         = C.SQLITE_TRANSACTION
+	SQLITE_UPDATE              = C.SQLITE_UPDATE
+	SQLITE_ATTACH              = C.SQLITE_ATTACH
+	SQLITE_DETACH              = C.SQLITE_DETACH
+	SQLITE_ALTER_TABLE         = C.SQLITE_ALTER_TABLE
+	SQLITE_REINDEX             = C.SQLITE_REINDEX
+	SQLITE_ANALYZE             = C.SQLITE_ANALYZE
+	SQLITE_CREATE_VTABLE       = C.SQLITE_CREATE_VTABLE
+	SQLITE_DROP_VTABLE         = C.SQLITE_DROP_VTABLE
+	SQLITE_FUNCTION            = C.SQLITE_FUNCTION
+	SQLITE_SAVEPOINT           = C.SQLITE_SAVEPOINT
+	SQLITE_COPY                = C.SQLITE_COPY
+	SQLITE_RECURSIVE           = C.SQLITE_RECURSIVE
 )
 
 // SQLiteDriver implement sql.Driver.
@@ -440,6 +476,20 @@ func (c *SQLiteConn) RegisterUpdateHook(callback func(int, string, string, int64
 	}
 }
 
+// RegisterAuthorizer sets the authorizer for connection.
+//
+// The parameters to the callback are the operation (one of the constants
+// SQLITE_INSERT, SQLITE_DELETE, or SQLITE_UPDATE), and 1 to 3 arguments,
+// depending on operation. More details see:
+// https://www.sqlite.org/c3ref/c_alter_table.html
+func (c *SQLiteConn) RegisterAuthorizer(callback func(int, string, string, string) int) {
+	if callback == nil {
+		C.sqlite3_set_authorizer(c.db, nil, nil)
+	} else {
+		C.sqlite3_set_authorizer(c.db, (*[0]byte)(C.authorizerTrampoline), unsafe.Pointer(newHandle(c, callback)))
+	}
+}
+
 // RegisterFunc makes a Go function available as a SQLite function.
 //
 // The Go function can have arguments of the following types: any
diff --git a/sqlite3_test.go b/sqlite3_test.go
index 75d8f52..bfed027 100644
--- a/sqlite3_test.go
+++ b/sqlite3_test.go
@@ -1574,6 +1574,47 @@ func TestUpdateAndTransactionHooks(t *testing.T) {
 	}
 }
 
+func TestAuthorizer(t *testing.T) {
+	var authorizerReturn = 0
+
+	sql.Register("sqlite3_Authorizer", &SQLiteDriver{
+		ConnectHook: func(conn *SQLiteConn) error {
+			conn.RegisterAuthorizer(func(op int, arg1, arg2, arg3 string) int {
+				return authorizerReturn
+			})
+			return nil
+		},
+	})
+	db, err := sql.Open("sqlite3_Authorizer", ":memory:")
+	if err != nil {
+		t.Fatal("Failed to open database:", err)
+	}
+	defer db.Close()
+
+	statements := []string{
+		"create table foo (id integer primary key, name varchar)",
+		"insert into foo values (9, 'test9')",
+		"update foo set name = 'test99' where id = 9",
+		"select * from foo",
+	}
+
+	authorizerReturn = SQLITE_OK
+	for _, statement := range statements {
+		_, err = db.Exec(statement)
+		if err != nil {
+			t.Fatalf("No error expected [%v]: %v", statement, err)
+		}
+	}
+
+	authorizerReturn = SQLITE_DENY
+	for _, statement := range statements {
+		_, err = db.Exec(statement)
+		if err == nil {
+			t.Fatalf("Authorizer didn't worked - nil received, but error expected: [%v]", statement)
+		}
+	}
+}
+
 func TestNilAndEmptyBytes(t *testing.T) {
 	db, err := sql.Open("sqlite3", ":memory:")
 	if err != nil {