[php-src] Issue #10312: PDO_DBLIB encodes passed binary data as a string, which is fragile

Issue: https://github.com/php/php-src/issues/10312 Author: NattyNarwhal ### Description A user reported an issue to me where they're trying to insert binary data (a PNG file, bound as a PARAM_LOB, inserting into a varbinary column) into an SQL Server database, and unexpectedly get a syntax error back. It looks like PDO_DBLIB doesn't actually implement binding (no param hook is implemented), so it relies on PDO to do substitution and send the fully substituted query string back to the server (I assume this is a FreeTDS, or TDS protocol limitation. It's been a long, long time since I touched SQL Server...), instead of sending the query and parameters separate. The PDO parsing defers to the driver's quoter to turn the value into a string, escaping things like ' and \. However, it seems this isn't sufficient with binary data that could have things like nulls in the middle of the string. The following code: ```php <?php try { $image1 = base64_decode("..."); // a PNG image in this case $pdo = new PDO("dblib:host=SQLTEST;dbname=test", "sa", "..."); if ($pdo) { $sql = "insert into dbo.TicketImage (TicketID, Image1, Image2) VALUES (168, ?, NULL)"; $stmt = $pdo->prepare($sql); $stmt->bindParam(1, $image1, PDO::PARAM_LOB); $stmt->execute(); } } catch (PDOException $e) { var_dump($e); } ``` Resulted in this output: ``` object(PDOException)#3 (8) { ["message":protected]=> string(165) "SQLSTATE[HY000]: General error: 20018 Incorrect syntax near ''. [20018] (severity 15) [insert into dbo.TicketImage (TicketID, Image1, Image2) VALUES (168, '�PNG � ]" ["string":"Exception":private]=> string(0) "" ["code":protected]=> string(5) "HY000" ["file":protected]=> string(59) "/home/calvin/src/sqlserver/sql server binary blob issue.php" ["line":protected]=> int(16) ["trace":"Exception":private]=> array(1) { [0]=> array(5) { ["file"]=> string(59) "/home/calvin/src/sqlserver/sql server binary blob issue.php" ["line"]=> int(16) ["function"]=> string(7) "execute" ["class"]=> string(12) "PDOStatement" ["type"]=> string(2) "->" } } ["previous":"Exception":private]=> NULL ["errorInfo"]=> array(5) { [0]=> string(5) "HY000" [1]=> int(20018) [2]=> string(127) "Incorrect syntax near ''. [20018] (severity 15) [insert into dbo.TicketImage (TicketID, Image1, Image2) VALUES (168, '�PNG � ]" [3]=> int(-1) [4]=> int(15) } } ``` But I expected this output instead: ``` // success... ``` ## Other details SQL Server version: ``` Microsoft SQL Server 2016 (SP2) (KB4052908) - 13.0.5026.0 (X64) Mar 18 2018 09:11:49 Copyright (c) Microsoft Corporation Express Edition (64-bit) on Windows Server 2016 Standard 10.0 <X64> (Build 14393: ) (Hypervisor) ``` FreeTDS info: ``` Compile-time settings (established with the "configure" script) Version: freetds v1.3.3 freetds.conf directory: /etc MS db-lib source compatibility: yes Sybase binary compatibility: yes Thread safety: yes iconv library: yes TDS version: auto iODBC: no unixodbc: yes SSPI "trusted" logins: no Kerberos: yes OpenSSL: no GnuTLS: yes MARS: yes ``` The provided table: ```sql CREATE TABLE [dbo].[TicketImage]( [TicketID] [int] NOT NULL, [Image1] [varbinary](max) NULL, [Image2] [varbinary](max) NULL, CONSTRAINT [PK_TicketImage] PRIMARY KEY CLUSTERED ( [TicketID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO ``` ### PHP Version PHP 8.1.13 ### Operating System Fedora 37