Hacker's ramblings

One day I needed to drill a hole to a Cisco firewall. I went to Adaptive Security Device Manager and could not log in. Whaat?!

It did work before, but apparently something changed. Sneak peek with Wireshark revealed that SSL handshake failed. Java console has something like this in it:

java.lang.SecurityException: Missing required Permissions manifest attribute in main jar: https://dm-launcher.jar
    at com.sun.deploy.security.DeployManifestChecker.verifyMainJar(Unknown Source)
    at com.sun.deploy.security.DeployManifestChecker.verifyMainJar(Unknown Source)
    at com.sun.javaws.Launcher.doLaunchApp(Unknown Source)
    at com.sun.javaws.Launcher.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

and:

javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: Java couldn't trust Server
    at sun.security.ssl.Alerts.getSSLException(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)

Little bit of googling revealed Issues Accessing ASDM at Cisco's learning network and Cisco ASDM blocked by Java? at spiceworks.com. So I wasn't alone with the problem. Oracle's release notes for update 51 revealed a number of changes to earlier versions. Java is still piece of shit, but they're trying to fix it. Too little, too late. It is very unfortunate that I have to have Java Runtime installed and use it for a number of important applications. Now Oracle is making radical changes to JRE to improve its flaky security and these customer companies like Cisco cannot keep up with the changes.

Anyway, enough rant, here is how to fix it. The idea is to take the self-signed certificate from the Cisco firewall and import it for Java. This is yet another nice feature of a Windows-computer. There needs to be separate a separate certificate store for operating system, browser and Java.

First go to web-interface of the Cisco appliance. Internet Explorer cannot export a certificate from a web site, so use a Firefox or Chrome or pretty much any other browser. Save the certificate to a file. Like this:

When you have the file, go to Control Panel on Windows:

Select Java and Security-tab:

From there you can find Manage Certificates. Import the certificate-file from there:

It is very, very important that you first select Certificate Type: Secure Site. Any other certificate type won't fix the problem.

On the security-tab there is an exception list for certificates. Adding an exception won't fix this, since the problem is with the fact that the certificate is self-signed.

Now login works again.
When I first encountered this issue, I asked help from couple of guys who are very familiar with Cisco IOS (not Apple iOS). The initial response was "What is ASDM?" Apparently the GUI is not the expert's way to go.

Once upon a time there was a Firefox version which remembered where something was saved from a website. I think the last download destination directory was stored per host. I clearly remember that when I downloaded something from SourceForge, it would remember the directory, but since there are number of projects I download from it didn't always be a correct one. But for websites, I use for only one piece of software, it was always correct.

Then something changed. My Firefox wouldn't remember my destinations anymore.

Now for some nostalgic reason I wanted the functionality back. My loyal/hated aide Google found me a solution for that. A Mozilla support forum discussion named Changing FF25 download location in Win7 - Browse will not get past /User folder. It clearly states that such a setting exists, but is now off by default. When I went to my about:config, it looked like this:

Like the support forum promised, the configuration directive is hidden. They say hidden, but actually it is not created at all. Luckily you can add it by yourself by right clicking on the Firefox configuration:

Just add a new boolean variable with name browser.download.lastDir.savePerSite and you're good to go. Remember to set the value into true. It is enabled immediately, no restarting or anything needed.

The last thing for me to do is keep wondering why it was enabled in a couple of versions when it was introduced and then turned off.

I was inspecting the already fallen Bitcoin exhange Mt. Gox's source code at PasteBin and found a nice discussion thread about it at Hacker News with the title of Alleged Mt.Gox code leaked on IRC node by Russian Hacker. To my great surprise, the Bitcoin exchange was written with PHP by Mark Karpeles (aka. MagicalTux), the CEO/owner of Mt. Gox. According to number of sources thinks he is some kind of PHP-deity. Based on his (alleged) work posted to Bitcoin, I'd say no.

Anyway, I got lost reading Mr. Alex Munroe's (aka. veekun) rant about PHP. It is so good stuff, I'll have to copy/paste his entire very long blog post here as-is just to make sure it is not lost in the digital world. To repeat: I did not write this. This does not reflect my opinions. It is just a comprehensive list of all the weird things that bug Mr. Munroe. All rights for this are his, not mine. And lot of thanks for gathering this huge list.

Here goes:

Preface

I’m cranky. I complain about a lot of things. There’s a lot in the world of technology I don’t like, and that’s really to be expected—programming is a hilariously young discipline, and none of us have the slightest clue what we’re doing. Combine with Sturgeon’s Law, and I have a lifetime’s worth of stuff to gripe about.

This is not the same. PHP is not merely awkward to use, or ill-suited for what I want, or suboptimal, or against my religion. I can tell you all manner of good things about languages I avoid, and all manner of bad things about languages I enjoy. Go on, ask! It makes for interesting conversation.

PHP is the lone exception. Virtually every feature in PHP is broken somehow. The language, the framework, the ecosystem, are all just bad. And I can’t even point out any single damning thing, because the damage is so systemic. Every time I try to compile a list of PHP gripes, I get stuck in this depth-first search discovering more and more appalling trivia. (Hence, fractal.)

PHP is an embarrassment, a blight upon my craft. It’s so broken, but so lauded by every empowered amateur who’s yet to learn anything else, as to be maddening. It has paltry few redeeming qualities and I would prefer to forget it exists at all.

But I’ve got to get this out of my system. So here goes, one last try.

An analogy

I just blurted this out to Mel to explain my frustration and she insisted that I reproduce it here.

I can’t even say what’s wrong with PHP, because— okay. Imagine you have uh, a toolbox. A set of tools. Looks okay, standard stuff in there.

You pull out a screwdriver, and you see it’s one of those weird tri-headed things. Okay, well, that’s not very useful to you, but you guess it comes in handy sometimes.

You pull out the hammer, but to your dismay, it has the claw part on both sides. Still serviceable though, I mean, you can hit nails with the middle of the head holding it sideways.

You pull out the pliers, but they don’t have those serrated surfaces; it’s flat and smooth. That’s less useful, but it still turns bolts well enough, so whatever.

And on you go. Everything in the box is kind of weird and quirky, but maybe not enough to make it completely worthless. And there’s no clear problem with the set as a whole; it still has all the tools.

Now imagine you meet millions of carpenters using this toolbox who tell you “well hey what’s the problem with these tools? They’re all I’ve ever used and they work fine!” And the carpenters show you the houses they’ve built, where every room is a pentagon and the roof is upside-down. And you knock on the front door and it just collapses inwards and they all yell at you for breaking their door.

That’s what’s wrong with PHP.

Stance

I assert that the following qualities are important for making a language productive and useful, and PHP violates them with wild abandon. If you can’t agree that these are crucial, well, I can’t imagine how we’ll ever agree on much.

• A language must be predictable. It’s a medium for expressing human ideas and having a computer execute them, so it’s critical that a human’s understanding of a program actually be correct.
• A language must be consistent. Similar things should look similar, different things different. Knowing part of the language should aid in learning and understanding the rest.
• A language must be concise. New languages exist to reduce the boilerplate inherent in old languages. (We could all write machine code.) A language must thus strive to avoid introducing new boilerplate of its own.
• A language must be reliable. Languages are tools for solving problems; they should minimize any new problems they introduce. Any “gotchas” are massive distractions.
• A language must be debuggable. When something goes wrong, the programmer has to fix it, and we need all the help we can get.

My position is thus:

• PHP is full of surprises: mysql_real_escape_string, E_ALL
• PHP is inconsistent: strpos, str_rot13
• PHP requires boilerplate: error-checking around C API calls, ===
• PHP is flaky: ==, foreach ($foo as &$bar)
• PHP is opaque: no stack traces by default or for fatals, complex error reporting

I can’t provide a paragraph of commentary for every single issue explaining why it falls into these categories, or this would be endless. I trust the reader to, like, think.

Don’t comment with these things

I’ve been in PHP arguments a lot. I hear a lot of very generic counter-arguments that are really only designed to halt the conversation immediately. Don’t pull these on me, please.

• Do not tell me that “good developers can write good code in any language”, or bad developers blah blah. That doesn’t mean anything. A good carpenter can drive in a nail with either a rock or a hammer, but how many carpenters do you see bashing stuff with rocks? Part of what makes a good developer is the ability to choose the tools that work best.
• Do not tell me that it’s the developer’s responsibility to memorize a thousand strange exceptions and surprising behaviors. Yes, this is necessary in any system, because computers suck. That doesn’t mean there’s no upper limit for how much zaniness is acceptable in a system. PHP is nothing but exceptions, and it is not okay when wrestling the language takes more effort than actually writing your program. My tools should not create net positive work for me to do.
• Do not tell me “that’s how the C API works”. What on Earth is the point of using a high-level language if all it provides are some string helpers and a ton of verbatim C wrappers? Just write C! Here, there’s even a CGI library for it.
• Do not tell me “that’s what you get for doing weird things”. If two features exist, someday, someone will find a reason to use them together. And again, this isn’t C; there’s no spec, there’s no need for “undefined behavior”.
• Do not tell me that Facebook and Wikipedia are built in PHP. I’m aware! They could also be written in Brainfuck, but as long as there are smart enough people wrangling the things, they can overcome problems with the platform. For all we know, development time could be halved or doubled if these products were written in some other language; this data point alone means nothing.
• Ideally, don’t tell me anything! This is my one big shot; if this list doesn’t hurt your opinion of PHP, nothing ever will, so stop arguing with some dude on the Internet and go make a cool website in record time to prove me wrong

Side observation: I loooove Python. I will also happily talk your ear off complaining about it, if you really want me to. I don’t claim it’s perfect; I’ve just weighed its benefits against its problems and concluded it’s the best fit for things I want to do.

And I have never met a PHP developer who can do the same with PHP. But I’ve bumped into plenty who are quick to apologize for anything and everything PHP does. That mindset is terrifying.

PHP

Core language

CPAN has been called the “standard library of Perl”. That doesn’t say much about Perl’s standard library, but it makes the point that a solid core can build great things.

Philosophy

• PHP was originally designed explicitly for non-programmers (and, reading between the lines, non-programs); it has not well escaped its roots. A choice quote from the PHP 2.0 documentation, regarding + and friends doing type conversion:

  Once you start having separate operators for each type you start making the language much more complex. ie. you can’t use ‘==’ for stings [sic], you now would use ‘eq’. I don’t see the point, especially for something like PHP where most of the scripts will be rather simple and in most cases written by non-programmers who want a language with a basic logical syntax that doesn’t have too high a learning curve.

• PHP is built to keep chugging along at all costs. When faced with either doing something nonsensical or aborting with an error, it will do something nonsensical. Anything is better than nothing.
• There’s no clear design philosophy. Early PHP was inspired by Perl; the huge stdlib with “out” params is from C; the OO parts are designed like C++ and Java.
• PHP takes vast amounts of inspiration from other languages, yet still manages to be incomprehensible to anyone who knows those languages. (int) looks like C, but int doesn’t exist. Namespaces use \. The new array syntax results in [key => value], unique among every language with hash literals.
• Weak typing (i.e., silent automatic conversion between strings/numbers/et al) is so complex that whatever minor programmer effort is saved is by no means worth it.
• Little new functionality is implemented as new syntax; most of it is done with functions or things that look like functions. Except for class support, which deserved a slew of new operators and keywords.
• Some of the problems listed on this page do have first-party solutions—if you’re willing to pay Zend for fixes to their open-source programming language.
• There is a whole lot of action at a distance. Consider this code, taken from the PHP docs somewhere.

    @fopen('http://example.com/not-existing-file', 'r');
  

  What will it do?
  • If PHP was compiled with --disable-url-fopen-wrapper, it won’t work. (Docs don’t say what “won’t work” means; returns null, throws exception?) Note that this flag was removed in PHP 5.2.5.
  • If allow_url_fopen is disabled in php.ini, this still won’t work. (How? No idea.)
  • Because of the @, the warning about the non-existent file won’t be printed.
  • But it will be printed if scream.enabled is set in php.ini.
  • Or if scream.enabled is set manually with ini_set.
  • But not if the right error_reporting level isn’t set.
  • If it is printed, exactly where it goes depends on display_errors, again in php.ini. Or ini_set.
  I can’t tell how this innocuous function call will behave without consulting compile-time flags, server-wide configuration, and configuration done in my program. And this is all built in behavior.
• The language is full of global and implicit state. mbstring uses a global character set. func_get_arg and friends look like regular functions, but operate on the currently-executing function. Error/exception handling have global defaults. register_tick_function sets a global function to run every tick—what?!
• There is no threading support whatsoever. (Not surprising, given the above.) Combined with the lack of built-in fork (mentioned below), this makes parallel programming extremely difficult.
• Parts of PHP are practically designed to produce buggy code.
  • json_decode returns null for invalid input, even though null is also a perfectly valid object for JSON to decode to—this function is completely unreliable unless you also call json_last_error every time you use it.
  • array_search, strpos, and similar functions return 0 if they find the needle at position zero, but false if they don’t find it at all.

  Let me expand on that last part a bit.

  In C, functions like strpos return -1 if the item isn’t found. If you don’t check for that case and try to use that as an index, you’ll hit junk memory and your program will blow up. (Probably. It’s C. Who the fuck knows. I’m sure there are tools for this, at least.)

  In, say, Python, the equivalent .index methods will raise an exception if the item isn’t found. If you don’t check for that case, your program will blow up.

  In PHP, these functions return false. If you use FALSE as an index, or do much of anything with it except compare with ===, PHP will silently convert it to 0 for you. Your program will not blow up; it will, instead, do the wrong thing with no warning, unless you remember to include the right boilerplate around every place you use strpos and certain other functions.

  This is bad! Programming languages are tools; they’re supposed to work with me. Here, PHP has actively created a subtle trap for me to fall into, and I have to be vigilant even with such mundane things as string operations and equality comparison. PHP is a minefield.

I have heard a great many stories about the PHP interpreter and its developers from a great many places. These are from people who have worked on the PHP core, debugged PHP core, interacted with core developers. Not a single tale has been a compliment.

So I have to fit this in here, because it bears repeating: PHP is a community of amateurs. Very few people designing it, working on it, or writing code in it seem to know what they’re doing. (Oh, dear reader, you are of course a rare exception!) Those who do grow a clue tend to drift away to other platforms, reducing the average competence of the whole. This, right here, is the biggest problem with PHP: it is absolutely the blind leading the blind.

Okay, back to facts.

Operators

• == is useless.
  • It’s not transitive. "foo" == TRUE, and "foo" == 0… but, of course, TRUE != 0.
  • == converts to numbers when possible (123 == "123foo"… although "123" != "123foo"), which means it converts to floats when possible. So large hex strings (like, say, password hashes) may occasionally compare true when they’re not. Even JavaScript doesn’t do this.
  • For the same reason, "6" == " 6", "4.2" == "4.20", and "133" == "0133". But note that 133 != 0133, because 0133 is octal. But "0x10" == "16" and "1e3" == "1000"!
  • === compares values and type… except with objects, where === is only true if both operands are actually the same object! For objects, == compares both value (of every attribute) and type, which is what === does for every other type. What.
• Comparison isn’t much better.
  • It’s not even consistent: NULL < -1, and NULL == 0. Sorting is thus nondeterministic; it depends on the order in which the sort algorithm happens to compare elements.
  • The comparison operators try to sort arrays, two different ways: first by length, then by elements. If they have the same number of elements but different sets of keys, though, they are uncomparable.
  • Objects compare as greater than anything else… except other objects, which they are neither less than nor greater than.
  • For a more type-safe ==, we have ===. For a more type-safe <, we have… nothing. "123" < "0124", always, no matter what you do. Casting doesn’t help, either.
• Despite the craziness above, and the explicit rejection of Perl’s pairs of string and numeric operators, PHP does not overload +. + is always addition, and . is always concatenation.
• The [] indexing operator can also be spelled {}.
• [] can be used on any variable, not just strings and arrays. It returns null and issues no warning.
• [] cannot slice; it only retrieves individual elements.
• foo()[0] is a syntax error. (Fixed in PHP 5.4.)

• Unlike (literally!) every other language with a similar operator, ?: is left associative. So this:

    $arg = 'T';
    $vehicle = ( ( $arg == 'B' ) ? 'bus' :
                 ( $arg == 'A' ) ? 'airplane' :
                 ( $arg == 'T' ) ? 'train' :
                 ( $arg == 'C' ) ? 'car' :
                 ( $arg == 'H' ) ? 'horse' :
                 'feet' );
    echo $vehicle;
  

  prints horse.

Variables

• There is no way to declare a variable. Variables that don’t exist are created with a null value when first used.
• Global variables need a global declaration before they can be used. This is a natural consequence of the above, so it would be perfectly reasonable, except that globals can’t even be read without an explicit declaration—PHP will quietly create a local with the same name, instead. I’m not aware of another language with similar scoping issues.
• There are no references. What PHP calls references are really aliases; there’s nothing that’s a step back, like Perl’s references, and there’s no pass-by-object identity like in Python.
• “Referenceness” infects a variable unlike anything else in the language. PHP is dynamically-typed, so variables generally have no type… except references, which adorn function definitions, variable syntax, and assignment. Once a variable is made a reference (which can happen anywhere), it’s stuck as a reference. There’s no obvious way to detect this and un-referencing requires nuking the variable entirely.
• Okay, I lied. There are “SPL types” which also infect variables: $x = new SplBool(true); $x = "foo"; will fail. This is like static typing, you see.
• A reference can be taken to a key that doesn’t exist within an undefined variable (which becomes an array). Using a non-existent array normally issues a notice, but this does not.
• Constants are defined by a function call taking a string; before that, they don’t exist. (This may actually be a copy of Perl’s use constant behavior.)
• Variable names are case-sensitive. Function and class names are not. This includes method names, which makes camelCase a strange choice for naming.

Constructs

• array() and a few dozen similar constructs are not functions. array on its own means nothing, $func = "array"; $func(); doesn’t work.
• Array unpacking can be done with the list($a, $b) = ... operation. list() is function-like syntax just like array. I don’t know why this wasn’t given real dedicated syntax, or why the name is so obviously confusing.
• (int) is obviously designed to look like C, but it’s a single token; there’s nothing called int in the language. Try it: not only does var_dump(int) not work, it throws a parse error because the argument looks like the cast operator.
• (integer) is a synonym for (int). There’s also (bool)/(boolean) and (float)/(double)/(real).
• There’s an (array) operator for casting to array and an (object) for casting to object. That sounds nuts, but there’s almost a use: you can use (array) to have a function argument that’s either a single item or a list, and treat it identically. Except you can’t do that reliably, because if someone passes a single object, casting it to an array will actually produce an array containing that object’s attributes. (Casting to object performs the reverse operation.)
• include() and friends are basically C’s #include: they dump another source file into yours. There is no module system, even for PHP code.
• There’s no such thing as a nested or locally-scoped function or class. They’re only global. Including a file dumps its variables into the current function’s scope (and gives the file access to your variables), but dumps functions and classes into global scope.
• Appending to an array is done with $foo[] = $bar.
• echo is a statement-y kind of thing, not a function.
• empty($var) is so extremely not-a-function that anything but a variable, e.g. empty($var || $var2), is a parse error. Why on Earth does the parser need to know about empty? (Fixed in 5.5.)
• There’s redundant syntax for blocks: if (...): ... endif;, etc.

Error handling

• PHP’s one unique operator is @ (actually borrowed from DOS), which silences errors.
• PHP errors don’t provide stack traces. You have to install a handler to generate them. (But you can’t for fatal errors—see below.)
• PHP parse errors generally just spew the parse state and nothing more, making a forgotten quote terrible to debug.
• PHP’s parser refers to e.g. :: internally as T_PAAMAYIM_NEKUDOTAYIM, and the << operator as T_SL. I say “internally”, but as above, this is what’s shown to the programmer when :: or << appears in the wrong place.
• Most error handling is in the form of printing a line to a server log nobody reads and carrying on.
• E_STRICT is a thing, but it doesn’t seem to actually prevent much and there’s no documentation on what it actually does.
• E_ALL includes all error categories—except E_STRICT. (Fixed in 5.4.)

• Weirdly inconsistent about what’s allowed and what isn’t. I don’t know how E_STRICT applies here, but these things are okay:

  • Trying to access a non-existent object property, i.e., $foo->x. (warning)
  • Using a variable as a function name, or variable name, or class name. (silent)
  • Trying to use an undefined constant. (notice)
  • Trying to access a property of something that isn’t an object. (notice)
  • Trying to use a variable name that doesn’t exist. (notice)
  • 2 < "foo" (silent)
  • foreach (2 as $foo); (warning)

  And these things are not:

  • Trying to access a non-existent class constant, i.e., $foo::x. (fatal error)
  • Using a constant string as a function name, or variable name, or class name. (parse error)
  • Trying to call an undefined function. (fatal error)
  • Leaving off a semicolon on the last statement in a block or file. (parse error)
  • Using list and various other quasi-builtins as method names. (parse error)
  • Subscripting the return value of a function, i.e., foo()[0]. (parse error; okay in 5.4, see above)

  There are a good few examples of other weird parse errors elsewhere in this list.

• The __toString method can’t throw exceptions. If you try, PHP will… er, throw an exception. (Actually a fatal error, which would be passable, except…)
• PHP errors and PHP exceptions are completely different beasts. They don’t seem to interact at all.
  • PHP errors (internal ones, and calls to trigger_error) cannot be caught with try/catch.
  • Likewise, exceptions do not trigger error handlers installed by set_error_handler.
  • Instead, there’s a separate set_exception_handler which handles uncaught exceptions, because wrapping your program’s entry point in a try block is impossible in the mod_php model.
  • Fatal errors (e.g., new ClassDoesntExist()) can’t be caught by anything. A lot of fairly innocuous things throw fatal errors, forcibly ending your program for questionable reasons. Shutdown functions still run, but they can’t get a stack trace (they run at top-level), and they can’t easily tell if the program exited due to an error or running to completion.
  • Trying to throw an object that isn’t an Exception results in… a fatal error, not an exception.
• There is no finally construct, making wrapper code (set handler, run code, unset handler; monkeypatch, run a test, unmonkeypatch) tedious and difficult to write. Despite that OO and exceptions were largely copied from Java, this is deliberate, because finally “doesn’t make much sense in the context of PHP”. Huh? (Fixed in 5.5.)

Functions

• Function calls are apparently rather expensive.
• Some built-in functions interact with reference-returning functions in, er, a strange way.
• As mentioned elsewhere, a lot of things that look like functions or look like they should be functions are actually language constructs, so nothing that works with functions will work with them.
• Function arguments can have “type hints”, which are basically just static typing. But you can’t require that an argument be an int or string or object or other “core” type, even though every builtin function uses this kind of typing, probably because int is not a thing in PHP. (See above about (int).) You also can’t use the special pseudo-type decorations used heavily by builtin functions: mixed, number, or callback. (callable is allowed as of PHP 5.4.)
  • As a result, this:

      function foo(string $s) {}
      foo("hello world");
    

    produces the error:

      PHP Catchable fatal error:  Argument 1 passed to foo()
      must be an instance of string, string given,
      called in...

  • You may notice that the “type hint” given doesn’t actually have to exist; there is no string class in this program. If you try to use ReflectionParameter::getClass() to examine the type hint dynamically, then it will balk that the class doesn’t exist, making it impossible to actually retrieve the class name.
  • A function’s return value can’t be hinted.
• Passing the current function’s arguments to another function (dispatch, not uncommon) is done by call_user_func_array('other_function', func_get_args()). But func_get_args throws a fatal error at runtime, complaining that it can’t be a function parameter. How and why is this even a type of error? (Fixed in PHP 5.3.)
• Closures require explicitly naming every variable to be closed-over. Why can’t the interpreter figure this out? Kind of hamstrings the whole feature. (Okay, it’s because using a variable ever, at all, creates it unless explicitly told otherwise.)
• Closed-over variables are “passed” by the same semantics as other function arguments. That is, arrays and strings etc. will be “passed” to the closure by value. Unless you use &.
• Because closed-over variables are effectively automatically-passed arguments and there are no nested scopes, a closure can’t refer to private methods, even if it’s defined inside a class. (Possibly fixed in 5.4? Unclear.)
• No named arguments to functions. Actually explicitly rejected by the devs because it “makes for messier code”.
• Function arguments with defaults can appear before function arguments without, even though the documentation points out that this is both weird and useless. (So why allow it?)
• Extra arguments to a function are ignored (except with builtin functions, which raise an error). Missing arguments are assumed null.
• “Variadic” functions require faffing about with func_num_args, func_get_arg, and func_get_args. There’s no syntax for such a thing.

OO

• The procedural parts of PHP are designed like C, but the objectional (ho ho) parts are designed like Java. I cannot overemphasize how jarring this is. The class system is designed around the lower-level Java language which is naturally and deliberately more limited than PHP’s contemporaries, and I am baffled.
  • I’ve yet to find a global function that even has a capital letter in its name, yet important built-in classes use camelCase method names and have getFoo Java-style accessors.
  • Perl, Python, and Ruby all have some concept of “property” access via code; PHP has only the clunky __get and friends. (The documentation inexplicably refers to such special methods as “overloading”.)
  • Classes have something like variable declaration (var and const) for class attributes, whereas the procedural part of the language does not.
  • Despite the heavy influence from C++/Java, where objects are fairly opaque, PHP often treats objects like fancy hashes—for example, the default behavior of foreach ($obj as $key => $value) is to iterate over every accessible attribute of the object.
• Classes are not objects. Any metaprogramming has to refer to them by string name, just like functions.
• Built-in types are not objects and (unlike Perl) can in no way be made to look like objects.
• instanceof is an operator, despite that classes were a late addition and most of the language is built on functions and function-ish syntax. Java influence? Classes not first-class? (I don’t know if they are.)
  • But there is an is_a function. With an optional argument specifying whether to allow the object to actually be a string naming a class.
  • get_class is a function; there’s no typeof operator. Likewise is_subclass_of.
  • This doesn’t work on builtin types, though (again, int is not a thing). For that, you need is_int etc.
  • Also the right-hand side has to be a variable or literal string; it can’t be an expression. That causes… a parse error.
• clone is an operator?!
• Object attributes are $obj->foo, but class attributes are Class::$foo. ($obj::$foo will try to stringify $obj and use it as a class name.) Class attributes can’t be accessed via objects; the namespaces are completely separate, making class attributes completely useless for polymorphism. Class methods, of course, are exempt from this rule and can be called like any other method. (I am told C++ also does this. C++ is not a good example of fine OO.)
• Also, an instance method can still be called statically (Class::method()). If done so from another method, this is treated like a regular method call on the current $this. I think.
• new, private, public, protected, static, etc. Trying to win over Java developers? I’m aware this is more personal taste, but I don’t know why this stuff is necessary in a dynamic language—in C++ most of it’s about compilation and compile-time name resolution.
• PHP has first-class support for “abstract classes”, which are classes that cannot be instantiated. Code in similar languages achieves this by throwing an exception in the constructor.
• Subclasses cannot override private methods. Subclass overrides of public methods can’t even see, let alone call, the superclass’s private methods. Problematic for, say, test mocks.
• Methods cannot be named e.g. “list”, because list() is special syntax (not a function) and the parser gets confused. There’s no reason this should be ambiguous, and monkeypatching the class works fine. ($foo->list() is not a syntax error.)
• If an exception is thrown while evaluating a constructor’s arguments (e.g., new Foo(bar()) and bar() throws), the constructor won’t be called, but the destructor will be. (This is fixed in PHP 5.3.)
• Exceptions in __autoload and destructors cause fatal errors. (Fixed in PHP 5.3.6. So now a destructor might throw an exception literally anywhere, since it’s called the moment the refcount drops the zero. Hmm.)
• There are no constructors or destructors. __construct is an initializer, like Python’s __init__. There is no method you can call on a class to allocate memory and create an object.
• There is no default initializer. Calling parent::__construct() if the superclass doesn’t define its own __construct is a fatal error.
• OO brings with it an iterator interface that parts of the language (e.g., for...as) respect, but nothing built-in (like arrays) actually implements the interface. If you want an array iterator, you have to wrap it in an ArrayIterator. There are no built-in ways to chain or slice or otherwise work with iterators as first-class objects.
• Interfaces like Iterator reserve a good few unprefixed method names. If you want your class to be iterable (without the default behavior of iterating all of its attributes), but want to use a common method name like key or next or current, well, too bad.
• Classes can overload how they convert to strings and how they act when called, but not how they convert to numbers or any other builtin type.
• Strings, numbers, and arrays all have a string conversion; the language relies heavily on this. Functions and classes are strings. Yet trying to convert a built-in or user-defined object (even a Closure) to a string causes an error if it doesn’t define __toString. Even echo becomes potentially error-prone.
• There is no overloading for equality or ordering.
• Static variables inside instance methods are global; they share the same value across all instances of the class.

Standard library

Perl is “some assembly required”. Python is “batteries included”. PHP is “kitchen sink, but it’s from Canada and both faucets are labeled C”.

General

• There is no module system. You can compile PHP extensions, but which ones are loaded is specified by php.ini, and your options are for an extension to exist (and inject its contents into your global namespace) or not.
• As namespaces are a recent feature, the standard library isn’t broken up at all. There are thousands of functions in the global namespace.
• Chunks of the library are wildly inconsistent from one another.
  • Underscore versus not: strpos/str_rot13, php_uname/phpversion, base64_encode/urlencode, gettype/get_class
  • “to” versus 2: ascii2ebcdic, bin2hex, deg2rad, strtolower, strtotime
  • Object+verb versus verb+object: base64_decode, str_shuffle, var_dump versus create_function, recode_string
  • Argument order: array_filter($input, $callback) versus array_map($callback, $input), strpos($haystack, $needle) versus array_search($needle, $haystack)
  • Prefix confusion: usleep versus microtime
  • Case insensitive functions vary on where the i goes in the name.
  • About half the array functions actually start with array_. The others do not.
  • htmlentities and html_entity_decode are inverses of each other, with completely different naming conventions.
• Kitchen sink. The libary includes:
  • Bindings to ImageMagick, bindings to GraphicsMagick (which is a fork of ImageMagick), and a handful of functions for inspecting EXIF data (which ImageMagick can already do).
  • Functions for parsing bbcode, a very specific kind of markup used by a handful of particular forum packages.
  • Way too many XML packages. DOM (OO), DOM XML (not), libxml, SimpleXML, “XML Parser”, XMLReader/XMLWriter, and half a dozen more acronyms I can’t identify. There’s surely some kind of difference between these things and you are free to go figure out what that is.
  • Bindings for two particular credit card processors, SPPLUS and MCVE. What?
  • Three ways to access a MySQL database: mysql, mysqli, and the PDO abstraction thing.

C influence

This deserves its own bullet point, because it’s so absurd yet permeates the language. PHP is a high-level, dynamically-typed programming language. Yet a massive portion of the standard library is still very thin wrappers around C APIs, with the following results:

• “Out” parameters, even though PHP can return ad-hoc hashes or multiple arguments with little effort.
• At least a dozen functions for getting the last error from a particular subsystem (see below), even though PHP has had exceptions for eight years.
• Warts like mysql_real_escape_string, even though it has the same arguments as the broken mysql_escape_string, just because it’s part of the MySQL C API.
• Global behavior for non-global functionality (like MySQL). Using multiple MySQL connections apparently requires passing a connection handle on every function call.
• The wrappers are really, really, really thin. For example, calling dba_nextkey without calling dba_firstkey will segfault.
• The wrappers are often platform-specific: fopen(directory, "r") works on Linux but returns false and generates a warning on Windows.
• There’s a set of ctype_* functions (e.g. ctype_alnum) that map to the C character-class detection functions of similar names, rather than, say, isupper.

Genericism

There is none. If a function might need to do two slightly different things, PHP just has two functions.

How do you sort backwards? In Perl, you might do sort { $b <=> $a }. In Python, you might do .sort(reverse=True). In PHP, there’s a separate function called rsort().

• Functions that look up a C error: curl_error, json_last_error, openssl_error_string, imap_errors, mysql_error, xml_get_error_code, bzerror, date_get_last_errors, others?
• Functions that sort: array_multisort, arsort, asort, ksort, krsort, natsort, natcasesort, sort, rsort, uasort, uksort, usort
• Functions that find text: ereg, eregi, mb_ereg, mb_eregi, preg_match, strstr, strchr, stristr, strrchr, strpos, stripos, strrpos, strripos, mb_strpos, mb_strrpos, plus the variations that do replacements
• There are a lot of aliases as well, which certainly doesn’t help matters: strstr/strchr, is_int/is_integer/is_long, is_float/is_double, pos/current, sizeof/count, chop/rtrim, implode/join, die/exit, trigger_error/user_error, diskfreespace/disk_free_space…
• scandir returns a list of files within a given directory. Rather than (potentially usefully) return them in directory order, the function returns the files already sorted. And there’s an optional argument to get them in reverse alphabetical order. There were not, apparently, enough sort functions. (PHP 5.4 adds a third value for the sort-direction argument that will disable sorting.)
• str_split breaks a string into chunks of equal length. chunk_split breaks a string into chunks of equal length, then joins them together with a delimiter.
• Reading archives requires a separate set of functions depending on the format. There are six separate groups of such functions, all with different APIs, for bzip2, LZF, phar, rar, zip, and gzip/zlib.
• Because calling a function with an array as its arguments is so awkward (call_user_func_array), there are some pairings like printf/vprintf and sprintf/vsprintf. These do the same things, but one function takes arguments and the other takes an array of arguments.

Text

• preg_replace with the /e (eval) flag will do a string replace of the matches into the replacement string, then eval it.
• strtok is apparently designed after the equivalent C function, which is already a bad idea for various reasons. Nevermind that PHP can easily return an array (whereas this is awkward in C), or that the very hack strtok(3) uses (modifying the string in-place) isn’t used here.
• parse_str parses a query string, with no indication of this in the name. Also it acts just like register_globals and dumps the query into your local scope as variables, unless you pass it an array to populate. (It returns nothing, of course.)
• explode refuses to split with an empty/missing delimiter. Every other string split implementation anywhere does some useful default in this case; PHP instead has a totally separate function, confusingly called str_split and described as “converting a string to an array”.
• For formatting dates, there’s strftime, which acts like the C API and respects locale. There’s also date, which has a completely different syntax and only works with English.
• ”gzgetss — Get line from gz-file pointer and strip HTML tags.” I’m dying to know the series of circumstances that led to this function’s conception.
• mbstring
  • It’s all about “multi-byte”, when the problem is character sets.
  • Still operates on regular strings. Has a single global “default” character set. Some functions allow specifying charset, but then it applies to all arguments and the return value.
  • Provides ereg_* functions, but those are deprecated. preg_* are out of luck, though they can understand UTF-8 by feeding them some PCRE-specific flag.

System and reflection

• There are, in general, a whole lot of functions that blur the line between text and variables. compact and extract are just the tip of the iceberg.
• There are several ways to actually be dynamic in PHP, and at a glance there are no obvious differences or relative benefits. classkit can modify user-defined classes; runkit supersedes it and can modify user-defined anything; the Reflection* classes can reflect on most parts of the language; there are a great many individual functions for reporting properties of functions and classes. Are these subsystems independent, related, redundant?
• get_class($obj) returns the object’s class name. get_class() returns the name of the class the function is being called in. Setting aside that this one function does two radically different things: get_class(null)… acts like the latter. So you can’t trust it on an arbitrary value. Surprise!
• The stream_* classes allow for implementing custom stream objects for use with fopen and other fileish builtins. “tell” cannot be implemented for internal reasons. (Also there are A LOT of functions involved with this system.)
• register_tick_function will accept a closure object. unregister_tick_function will not; instead it throws an error complaining that the closure couldn’t be converted to a string.
• php_uname tells you about the current OS. Unless PHP can’t tell what it’s running on; then it tells you about the OS it was built on. It doesn’t tell you if this has happened.
• fork and exec are not built in. They come with the pcntl extension, but that isn’t included by default. popen doesn’t provide a pid.
• stat’s return value is cached.
• session_decode is for reading an arbitrary PHP session string, but it only works if there’s an active session already. And it dumps the result into $_SESSION, rather than returning it.

Miscellany

• curl_multi_exec doesn’t change curl_errno on error, but it does change curl_error.
• mktime’s arguments are, in order: hour, minute, second, month, day, year.

Data manipulation

Programs are nothing more than big machines that chew up data and spit out more data. A great many languages are designed around the kinds of data they manipulate, from awk to Prolog to C. If a language can’t handle data, it can’t do anything.

Numbers

• Integers are signed and 32-bit on 32-bit platforms. Unlike all of PHP’s contemporaries, there is no automatic bigint promotion. So you can end up with surprises like negative file sizes, and your math might work differently based on CPU architecture. Your only option for larger integers is to use the GMP or BC wrapper functions. (The developers have proposed adding a new, separate, 64-bit type. This is crazy.)
• PHP supports octal syntax with a leading 0, so e.g. 012 will be the number ten. However, 08 becomes the number zero. The 8 (or 9) and any following digits disappear. 01c is a syntax error.
• 0x0+2 produces 4. The parser considers the 2 as both part of the hex literal and a separate decimal literal, treating this as 0x002 + 2. 0x0+0x2 displays the same problem. Strangely, 0x0 +2 is still 4, but 0x0+ 2 is correctly 2. (This is fixed in PHP 5.4. But it’s also re-broken in PHP 5.4, with the new 0b literal prefix: 0b0+1 produces 2.)
• pi is a function. Or there’s a constant, M_PI.
• There is no exponentiation operator, only the pow function.

Text

• No Unicode support. Only ASCII will work reliably, really. There’s the mbstring extension, mentioned above, but it kinda blows.
• Which means that using the builtin string functions on UTF-8 text risks corrupting it.
• Similarly, there’s no concept of e.g. case comparisons outside of ASCII. Despite the proliferation of case-insensitive versions of functions, not one of them will consider é equal to É.
• You can’t quote keys in variable interpolation, i.e., "$foo['key']" is a syntax error. You can unquote it (which would generate a warning anywhere else!), or use ${...}/{$...}.
• "${foo[0]}" is okay. "${foo[0][0]}" is a syntax error. Putting the $ on the inside is fine with both. Bad copy of similar Perl syntax (with radically different semantics)?

Arrays

Oh, man.

• This one datatype acts as a list, ordered hash, ordered set, sparse list, and occasionally some strange combination of those. How does it perform? What kind of memory use will there be? Who knows? Not like I have other options, anyway.
• => isn’t an operator. It’s a special construct that only exists inside array(...) and the foreach construct.
• Negative indexing doesn’t work, since -1 is just as valid a key as 0.
• Despite that this is the language’s only data structure, there is no shortcut syntax for it; array(...) is shortcut syntax. (PHP 5.4 is bringing “literals”, [...].)
• Similarly baffling, arrays stringify to Array with an E_NOTICE.
• The => construct is based on Perl, which allows foo => 1 without quoting. (That is, in fact, why it exists in Perl; otherwise it’s just a comma.) In PHP, you can’t do this without getting a warning; it’s the only language in its niche that has no vetted way to create a hash without quoting string keys.

• Array functions often have confusing or inconsistent behavior because they have to operate on lists, hashes, or maybe a combination of the two. Consider array_diff, which “computers the difference of arrays”.

    $first  = array("foo" => 123, "bar" => 456);
    $second = array("foo" => 456, "bar" => 123);
    echo var_dump(array_diff($first, $second));
  

  What will this code do? If array_diff treats its arguments as hashes, then obviously these are different; the same keys have different values. If it treats them as lists, then they’re still different; the values are in the wrong order.

  In fact array_diff considers these equal, because it treats them like sets: it compares only values, and ignores order.

• In a similar vein, array_rand has the strange behavior of selecting random keys, which is not that helpful for the most common case of needing to pick from a list of choices.

• Despite how heavily PHP code relies on preserving key order:

    array("foo", "bar") != array("bar", "foo")
    array("foo" => 1, "bar" => 2) == array("bar" => 2, "foo" => 1)
  

  I leave it to the reader to figure out what happens if the arrays are mixed. (I don’t know.)

• array_fill cannot create zero-length arrays; instead it will issue a warning and return false.
• All of the (many…) sort functions operate in-place and return nothing. There is no way to create a new sorted copy; you have to copy the array yourself, then sort it, then use the array.
• But array_reverse returns a new array.
• A list of ordered things and some mapping of keys to values sounds kind of like a great way to handle function arguments, but no.

Not arrays

• The standard library includes “Quickhash”, an OO implementation of “specific strongly-typed classes” for implementing hashes. And, indeed, there are four classes, each dealing with a different combination of key and value types. It’s unclear why the builtin array implementation can’t optimize for these extremely common cases, or what the relative performance is.
• There’s an ArrayObject class (which implements five different interfaces) that can wrap an array and have it act like an object. User classes can implement the same interfaces. But it only has a handful of methods, half of which don’t resemble built-in array functions, and built-in array functions don’t know how to operate on an ArrayObject or other array-like class.

Functions

• Functions are not data. Closures are actually objects, but regular functions are not. You can’t even refer to them with their bare names; var_dump(strstr) issues a warning and assumes you mean the literal string, "strstr". There is no way to discern between an arbitrary string and a function “reference”.
• create_function is basically a wrapper around eval. It creates a function with a regular name and installs it globally (so it will never be garbage collected—don’t use in a loop!). It doesn’t actually know anything about the current scope, so it’s not a closure. The name contains a NUL byte so it can never conflict with a regular function (because PHP’s parser fails if there’s a NUL in a file anywhere).
• Declaring a function named __lambda_func will break create_function—the actual implementation is to eval-create the function named __lambda_func, then internally rename it to the broken name. If __lambda_func already exists, the first part will throw a fatal error.

Other

• Incrementing (++) a NULL produces 1. Decrementing (--) a NULL produces NULL. Decrementing a string likewise leaves it unchanged.
• There are no generators. (Fixed in 5.5. Wow. They basically cloned the entire Python generator API, too. Impressive. Somehow, though, $foo = yield $bar; is a syntax error; it has to be $foo = (yield $bar). Sigh.)

Web framework

Execution

• A single shared file, php.ini, controls massive parts of PHP’s functionality and introduces complex rules regarding what overrides what and when. PHP software that expects to be deployed on arbitrary machines has to override settings anyway to normalize its environment, which largely defeats the use of a mechanism like php.ini anyway.
  • PHP looks for php.ini in a variety of places, so it may (or may not…) be possible to override your host’s. Only one such file will ever be parsed, though, so you can’t just override a couple settings and call it a day.
• PHP basically runs as CGI. Every time a page is hit, PHP recompiles the whole thing before executing it. Even dev servers for Python toy frameworks don’t act like this. This has led to a whole market of “PHP accelerators” that just compile once, accelerating PHP all the way to any other language. Zend, the company behind PHP, has made this part of their business model.
• For quite a long time, PHP errors went to the client by default—I guess to help during development. I don’t think this is true any more, but I still see the occasional mysql error spew at the top of a page.
• PHP is full of strange “easter eggs” like producing the PHP logo with the right query argument. Not only is this completely irrelevant to building your application, but it allows detecting whether you’re using PHP (and perhaps roughly guessing what version), regardless of how much mod_rewrite, FastCGI, reverse proxying, or Server: configuration you’re doing.
• Blank lines before or after the <?php ... ?> tags, even in libraries, count as literal text and is interpolated into the response (or causes “headers already sent” errors). Your options are to either strictly avoid extra blank lines at the end of every file (the one after the ?> doesn’t count) or to just leave off the ?> closing token.

Deployment

Deployment is often cited as the biggest advantage of PHP: drop some files and you’re done. Indeed, that’s much easier than running a whole process as you may have to do with Python or Ruby or Perl. But PHP leaves plenty to be desired.

Across the board, I’m in favor of running Web applications as app servers and reverse-proxying to them. It takes minimal effort to set this up, and the benefits are plenty: you can manage your web server and app separately, you can run as many or few app processes on as many machines as you want without needing more web servers, you can run the app as a different user with zero effort, you can switch web servers, you can take down the app without touching the web server, you can do seamless deployment by just switching where a fifo points, etc. Welding your application to your web server is absurd and there’s no good reason to do it any more.

• PHP is naturally tied to Apache. Running it separately, or with any other webserver, requires just as much mucking around (possibly more) as deploying any other language.
• php.ini applies to every PHP application run anywhere. There is only one php.ini file, and it applies globally; if you’re on a shared server and need to change it, or if you run two applications that need different settings, you’re out of luck; you have to apply the union of all necessary settings and pare them down from inside the apps themselves using ini_set or in Apache’s configuration file or in .htaccess. If you can. Also wow that is a lot of places you need to check to figure out how a setting is getting its value.
• Similarly, there is no easy way to “insulate” a PHP application and its dependencies from the rest of a system. Running two applications that require different versions of a library, or even PHP itself? Start by building a second copy of Apache.
• The “bunch of files” approach, besides making routing a huge pain in the ass, also means you have to carefully whitelist or blacklist what stuff is actually available, because your URL hierarchy is also your entire code tree. Configuration files and other “partials” need C-like guards to prevent them from being loaded directly. Version control noise (e.g., .svn) needs protecting. With mod_php, everything on your filesystem is a potential entry point; with an app server, there’s only one entry point, and only the URL controls whether it’s invoked.
• You can’t seamlessly upgrade a bunch of files that run CGI-style, unless you want crashes and undefined behavior as users hit your site halfway through the upgrade.

• Despite how “simple” it is to configure Apache to run PHP, there are some subtle traps even there. While the PHP docs suggest using SetHandler to make .php files run as PHP, AddHandler appears to work just as well, and in fact Google gives me twice as many results for it. Here’s the problem.

  When you use AddHandler, you are telling Apache that “execute this as php” is one possible way to handle .php files. But! Apache doesn’t have the same idea of file extensions that every human being on the planet does. It’s designed to support, say, index.html.en being recognized as both English and HTML. To Apache, a file can have any number of file extensions simultaneously.

  Imagine you have a file upload form that dumps files into some public directory. To make sure nobody uploads PHP files, you just check that they don’t have a .php extension. All an attacker has to do is upload a file named foo.php.txt; your uploader won’t see a problem, but Apache will recognize it as PHP, and it will happily execute.

  The problem here isn’t “using the original filename” or “not validating better”; the problem is that your web server is configured to run any old code it runs across—precisely the same property that makes PHP “easy to deploy”. CGI required +x, which was something, but PHP doesn’t even do that. And this is no theoretical problem; I’ve found multiple live sites with this issue.

Missing features

I consider all of these to be varying levels of critical for building a Web application. It seems reasonable that PHP, with its major selling point being that it’s a “Web language”, ought to have some of them.

• No template system. There’s PHP itself, but nothing that acts as a big interpolator rather than a program.
• No XSS filter. No, “remember to use htmlspecialchars” is not an XSS filter. This is.
• No CSRF protection. You get to do it yourself.
• No generic standard database API. Stuff like PDO has to wrap every individual database’s API to abstract the differences away.
• No routing. Your website looks exactly like your filesystem. Many developers have been tricked into thinking mod_rewrite (and .htaccess in general) is an acceptable substitute.
• No authentication or authorization.
• No dev server. (“Fixed” in 5.4. Led to the Content-Length vuln below. Also, you have to port all your rewrite rules to a PHP wrapper thing, because there’s no routing.)
• No interactive debugging.
• No coherent deployment mechanism; only “copy all these files to the server”.

Security

Language boundaries

PHP’s poor security reputation is largely because it will take arbitrary data from one language and dump it into another. This is a bad idea. "<script>" may not mean anything in SQL, but it sure does in HTML.

Making this worse is the common cry for “sanitizing your inputs”. That’s completely wrong; you can’t wave a magic wand to make a chunk of data inherently “clean”. What you need to do is speak the language: use placeholders with SQL, use argument lists when spawning processes, etc.

• PHP outright encourages “sanitizing”: there’s an entire data filtering extension for doing it.
• All the addslashes, stripslashes, and other slashes-related nonsense are red herrings that don’t help anything.
• There is, as far as I can tell, no way to safely spawn a process. You can ONLY execute a string via the shell. Your options are to escape like crazy and hope the default shell uses the right escaping, or pcntl_fork and pcntl_exec manually.
• Both escapeshellcmd and escapeshellarg exist with roughly similar descriptions. Note that on Windows, escapeshellarg does not work (because it assumes Bourne shell semantics), and escapeshellcmd just replaces a bunch of punctuation with spaces because nobody can figure out Windows cmd escaping (which may silently wreck whatever you’re trying to do).
• The original built-in MySQL bindings, still widely-used, have no way to create prepared statements.

To this day, the PHP documentation on SQL injection recommends batty practices like type-checking, using sprintf and is_numeric, manually using mysql_real_escape_string everywhere, or manually using addslashes everywhere (which “may be useful”!). There is no mention of PDO or paramaterization, except in the user comments. I complained about this very specifically to a PHP dev at least two years ago, he was alarmed, and the page has never changed.

Insecure-by-default

• register_globals. It’s been off by default for a while by now, and it’s gone in 5.4. I don’t care. This is an embarrassment.
• include accepting HTTP URLs. Likewise.
• Magic quotes. So close to secure-by-default, and yet so far from understanding the concept at all. And, likewise.
• You can, say, probe a network using PHP’s XML support, by abusing its ubiquitous support for filenames-as-URLs. Only libxml_disable_entity_loader() can fix this, and the problem is only mentioned in the manual comments.

(5.5 brings a just-do-it password hashing function, password_hash, which should hopefully cut down on hand-rolled crypto code.)

Core

The PHP interpreter itself has had some fascinating security problems.

• In 2007 the interpreter had an integer overflow vulnerability. The fix started with if (size > INT_MAX) return NULL; and went downhill from there. (For those not down with the C: INT_MAX is the biggest integer that will fit in a variable, ever. I hope you can figure out the rest from there.)
• More recently, PHP 5.3.7 managed to include a crypt() function that would, in effect, let anyone log in with any password.
• PHP 5.4’s dev server is vulnerable to a denial of service, because it takes the Content-Length header (which anyone can set to anything) and tries to allocate that much memory. This is a bad idea.

I could dig up more but the point isn’t that there are X many exploits—software has bugs, it happens, whatever. The nature of these is horrifying. And I didn’t seek these out; they just happened to land on my doorstep in the last few months.

Conclusion

Some commentary has rightfully pointed out that I don’t have a conclusion. And, well, I don’t have a conclusion. If you got all the way down here, I assumed you agreed with me before you started

If you only know PHP and you’re curious to learn something else, give the Python tutorial a whirl and try Flask for the web stuff. (I’m not a huge fan of its template language, but it does the job.) It breaks apart the pieces of your app, but they’re still the same pieces and should look familiar enough. I might write a real post about this later; a whirlwind introduction to an entire language and web stack doesn’t belong down here.

Later or for bigger projects you may want Pyramid, which is medium-level, or Django, which is a complex monstrosity that works well for building sites like Django’s.

If you’re not a developer at all but still read this for some reason, I will not be happy until everyone on the planet has gone through Learn Python The Hard Way so go do that.

There’s also Ruby with Rails and some competitors I’ve never used, and Perl is still alive and kicking with Catalyst. Read things, learn things, build things, go nuts.

Credits

Thanks to the following for inspiration:

• PHP turtles
• PHP sadness
• PHP WTF
• YourLanguageSucks
• PHP in contrast to Perl
• Pi’s dense, angry, inspirational rant
• PHP is not an acceptable COBOL
• the PHP documentation
• a ton of PHP fanatics and PHP counter-fanatics
• and, of course, Rasmus Lerdorf for his wild misunderstanding of most of Perl

Let me know if you have any additions, or if I’m (factually!) wrong about something.

Last summer, in Facebook, the source of all nasty things, had ads published for Trimatol-, Corexin- and Life Detox products by really evil Danish company called Health-C-P. See my blog post about it.

Everybody knows, that government officials work really hard and do what they can, but it so happens that no matter what they do, their actions are really slow. Today we had news from Finnish Consumer Center, that Nordic countries joint their efforts and made Danish government to extend a harsh warning. The news about that is in Finnish-only, sorry. The original warning about their mis-guided marketing tactics can be found here in English.

There was no punishment by Danish government. They just instructed Health-C-P to correct their marketing. Total bullshit!

Couple of times I've mentioned the Qualsys SSL Server Test in this blog. It is a really good (currently free) tool for evaluating your TLS/SSL server's security. Typically people run it to test their web servers, but it is no way limited to that. Anyway, it is a really good tool for any sysadmin.

Last week I was bailing out a customer when Namecheap's FreeDNS was under a huge DDoS. The irony of DDoSing a DNS was, that it was partly done with badly configured DNS's, actually a number of UDP-based protocols were used. See US-CERT's info about that.

In general the weak link in today's Internet is DNS. People don't recognize its importance for a business. I personally would like to see DNSSEC gaining more popularity to prevent cache poisoning, perhaps I'll blog about it later. But to fight those huge DDoS-attacks there is really no other way, than to use services from a service provider who has really big guns. The second thing any sysadmin can do is to make sure, they're not part of the problem. See my earlier post about that.

Last week I found a DNS-tool equal to Qualsys' tool. Its called DNS inspect and you can use it (currently) freely at http://www.dnsinspect.com/. It is a really good tool and gives you American school grade from A to F (mostly unknown by us European peope) about the target domain inspected. I warmly recommend all admins to check their domain and DNS setup with that tool.

Both of the tools I mentioned are really good. Good to the point I'd pay money to use them. Thanks to both companies for giving out those freely.

Anybody who has reached a certain level of skill in software development eventually will start thinking about how to make the job easier or be more productive during the day. With computers and programming, the tools you're using is a good starting point.

I've written code with a number of text editors (including vim and notepad), some of them really bad and some of them more suited to the task at hand. IMHO one of the best editors for a software developer is Microsoft's Visual Studio. Since many of my projects involve PHP, that is not the optimal editor for that. For years I used Notepad++, but then I got a recommendation for JetBrains PhpStorm. Since that it has become my weapon of choice for PHP.

For example, debugging the application is very simple operation. PhpStorm has all the client-stuff built into it, the only thing that is needed is Xdebug-extension to the server end. In my case, my web server is on a Linux and I typically work on a Windows 7. The debugging is done over my LAN. There is a very good article on PhpStorm author's web site with name Zero-configuration Web Application Debugging with Xdebug and PhpStorm. I don't think the zero-configuration part is true, but it is almost zero anyway.

On the server end I have a PHP-fpm running, it has

php_admin_flag[xdebug.remote_enable] = on
php_admin_value[xdebug.remote_host] = my_machine_name
php_admin_value[xdebug.remote_port] = 9000

In the worker configuration. That enables the server side to initiate a DBGP-connection to the given client (PhpStorm) and start sending data there. There reference for all the configuration directives can be found from Xdebug's docs.

On the PhpStorm end all you have to do, is enable the listener:

Also I had to drill a hole into my Windows 7 firewall, to allow my web server to connect into TCP/9000. If you're running a single machine setup, that won't be necessary.

Any settings for the setup can be found in the PhpStorm project:

But I think they're ok as a default. At least I didn't change anything there. If your debugger does not work, you fumbled the settings or your listener is not enabled. On Windows, run this on command prompt to confirm:

PS J:\> netstat -ano

Active Connections

  Proto  Local Address          Foreign Address        State           PID
  TCP    0.0.0.0:9000           0.0.0.0:0              LISTENING       ?

It will return a long list of things, but one of the entries must be similar to that.

To make the choice between debugging and not debugging can be made really easy. There are a number of ways of starting a debug session, but for Firefox users there is an excellent add-on The easiest Xdebug. It will add an icon to your add-on bar:

If the bug is green, it will send a special cookie to the server during a page load request:

Cookie: XDEBUG_SESSION=netbeans-xdebug

That will initiate the debugging session for you and PhpStorm will stop on a breakpoint if one is set.

Switching to PhpStorm vastly improved my productivity. I would imagaine, that it will do that for anybody.

I was renewing a SSL-certificate for a customer. They had been using GeoTrust earlier, so I went there. It was the first and most likely the last time I do business with them.

The order process was pretty similar to the competition. A CSR was submitted and all the necessary information was given. After submission there was a thank you -page and they sent an automated e-mail with information that the order is pending, and will be processed after 5 to 7 business days.

After that, nothing. After waiting for 12 days out of with 8 were business days, my patience ran out. I contacted them and requested to expedite the process. Yet another business day passed, and then they called me after 7 in the night and informed, that there was a mistake in the information I had gave them. I corrected the info, got automated e-mail about it and went into yet another wait.

Two more days later they sent an e-mail that the verification call to customer failed. Their mail had the number in it and it was obvious, that they assumed that the customer was located in USA. Even though, the information stated Finland as the country. I got an e-mail about that too.

At the point, when they issued the new certificate, I was surprised. Against all the odds, they managed to verify the customer in less than three weeks. The real suprise was, that at that point their e-mail replies started pouring in. The lag in their e-mail processing was huge. Last of the replies came 6 days after the certificate was issued. It's beyond stupid, that none of the communication I had with them were actually recorded for the purchase process. Apparely all of them went to a distant support site, which has nothing to do with any of their other actions or operations.

Is it just me, or does GeoTrust's way of doing business suck?

I maintain RPM-packages for PHP 5.4 and 5.5, see earlier post about it.

As any sysadmin can expect, there was too much trouble running the updates. Since CentOS 6 native way is running yum repositories, I created one.

Kick things going by installing the repo-definition:

yum install \
 http://opensource.hqcodeshop.com/CentOS/6%20x86_64/Parallels%20Plesk%20Panel/plesk-php-repo-1.0-1.el6.noarch.rpm

After that, a simple yum install command:

yum install plesk-php55

... will yield something like this:

/opt/php5.5/usr/bin/php -v
PHP 5.5.9 (cli) (built: Feb  9 2014 22:04:05)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies

I'll be compiling new versions to keep my own box in shape.

My favorite way of approaching DAL in ZF2 is ZeDb. It uses lot of existing functionality, but adds a nice layer of its own stuff, and that stuff is really good. However, ZeDb has one single flaw, it does not support multiple database connections. The typical thinking is, that who an earth would want that. I do. I want other weird things too, but in an everyday real application, you simply need more connections than one.

I came up with an simple solution by abusing ZF2's ServiceManager. Typically you gain access to a model is via something like this:

$manager = $this->getServiceLocator()->get('ZeDbManager');
$model = $manager->get('Application\Entity\Prices');

To get that working you need to do the config in module.config.php, declare ZeDb's DatabaseManagerFactory and override Zend\Db\Adapter\Adapter with AdapterFactory and finally declare your DB-configuration and list the models. Its all in the ZeDb docs.

My idea exploits all three of those. I'll instantiate multiple DatabaseManagers via ServiceManager. Also, every model will select an existing DB-adapter for itself. To get that working there will be separate configuration for all of the connections.

Example module configuration:

return array(
    'service_manager' => array(
        'factories' => array(
            'ZeDbManager' => 'ZeDb\Service\DatabaseManagerFactory',
            'Zend\Db\Adapter\Adapter' => 'ZeDb\Service\AdapterFactory',
        )
    ),
    'zedb_db_in' => array(
        'adapter' => array(
            'driver'    => 'pdo_pgsql',
        ),
        'models' => array(
            'Application\Model\Int\Products' => array(
                'tableName' => 'products',
                'entityClass' => 'Application\Entity\Int\Products',
            ),
        ),
    ),
    'zedb_db_out' => array(
        'adapter' => array(
            'driver'    => 'pdo_mysql',
        ),
        'models' => array(
            'Application\Model\Internal\Customers' => array(
                'tableName' => 'customers',
                'entityClass' => 'Application\Entity\Internal\Customers',
            ),
        ),
    ),

Here I declare the obligatory parts, and two separate configurations with names zedb_db_in and zedb_db_out.

I'll have to prime both the DatabaseManagers and Adapters in Module's onBootstrap(). After the objects exist, they are made accessible with:

public function getServiceConfig()
{
 return array(
  'factories' => array(
   'zedb_db_in' => function (ServiceLocatorInterface $sm) {
     return Module::getInDbManager();
    },
   'ZeDbAdapter_in' => function (ServiceLocatorInterface $sm) {
     return Module::getInDbAdapter();
    },
  ),
 );
}

The model has to do some heavy lifting to get rid of the default Adapter:

class Products extends ZeDb\Model
{
    public function __construct(Adapter $adapter, $options = null)
    {
        $adapter = $this->getDatabaseManager()
                        ->getServiceLocator()
                        ->get('ZeDbAdapter_in');
        parent::__construct($adapter, $options);
    }

    public function getDatabaseManager()
    {
        return Module::getInternalDbManager();
    }

Now the setup is ready. In an action you can simply do:

$inDbManager = $this->getServiceLocator()->get('zedb_db_in');
$productsModel = $inDbManager->get('Application\Entity\Int\Products');
$products = $productsModel->SearchProductByCode('ABC123', null);

There is no limit on how many DB-connections you can have. Note that, the ZeDb-module bootstrap will initialize the default manager and adapter, but the idea is not to use them at all. Anyway, I'll stick with this until something better comes.

This one really made me laugh. The entire situation was like from T-2: "Skynet begins to learn at a geometric rate. It becomes self-aware at 2:14 a.m."

Earlier I had trouble with with a disabled DNS-zone not staying disabled. I'm running version 11.5.30 Update #32.

The problem bugged me and I kept investigating. To debug, I enabled the DNS-zone and actually transferred it with AXFR to an external server. There I realized, that the SOA-record was bit strange. Further trials reveald that in the NS-records, there was always an extra one. With that in mind, I went directly to the database to see what I had stored there for the zone.

To access the MySQL database named psa, I have to get the password for that. See KB article ID 170 [How to] How can I access MySQL databases in Plesk? for details about that. The database schema is not documented, but it has become familiar to me during all the years I've been sysadmining Plesk Panels. To get the ID for the DNS-zone I did:

SELECT *
FROM dns_zone
WHERE name = '-the-zone-';

And what do you know! There were two IDs for the given name. That is a big no-no. It's like you having two heads. A freak of nature. It cannot happen. It is so illegal, that there aren't even laws about it. To fix that I did rename the one with a smaller ID:

UPDATE dns_zone
SET name = '-the-zone-_obsoleted', displayName = '-the-zone-_obsoleted'
WHERE id = -the-smaller-ID-;

After that a manual refresh of the BIND records from the DB:

/usr/local/psa/admin/bin/dnsmng --update -the-zone-

And confirmation from the raw BIND-file:

less /var/named/chroot/var/-the-zone-

Now everything was in order. I'm hoping that will help and keep the zone disabled. To me it is now obvious why that happened. Database had become badly skewed.

For any computer security geek (like I am), Metasploit is the de facto tool to use. What especially makes Metasploit so good, that there are number of places where you can get brand new exploits to run it with. It is obvious that Packet Storm is the #1 place for your new dose of exploits to run. They release exploits in ready packages for Metasploit on monthly basis. To help people catch up in their installations, there are also yearly packages combining year's monthly updates into a single file.

Due to popularity of Metasploit and quality of Packet Storm's exploits, there are number of instructions how to do the update. I googled "upadate metasploit with packet storm exploits" and got a ton of garbage. Really?! Couple dozen YouTube-videos showing how to do it. Videos?! Really!! Apparently all of those videos are created by script-kiddies for script-kiddies. It is soooo easy to copy/paste information from a YouTube-video, or ... then again, NOT. No matter which search phrases I used, I simply could not find a sensible way of doing the updates. When you don't find the required information from the web, it must be one of these two: 1) you're wrong or 2) everybody else is wrong. My typical choice is 2), ask anybody who knows me.

The single page with idea I found was at Mr. ljy396's blog "How to update exploits from packetstorm website". I was looking at his scripts of collecting and installing the exploits, and thought that there should be a single easy-to-use script for doing all this.

When I started writing my own script, the thought came to me again: "This is so wrong! There must be the real way of doing the updates, but I just didn't find it. It is obvious, that I'm writing an inferior duplicate thing for this." Anyway, that logic never stopped me so far. Here are the results.

The script operates in three modes:

• Do monthly updates:
  updateMetasploitFromPacketStormExploits.pl --year=2014
• Download and install a specific package:
  updateMetasploitFromPacketStormExploits.pl \
  --package_url=http://packetstorm.interhost.co.il/1401-exploits/1401-exploits.tgz
• Install an existing package:
  updateMetasploitFromPacketStormExploits.pl --package_file=/tmp/1401-exploits.tgz

A Metasploit user has the "secret" $HOME/.msf4/-directory. My script adds the updates/-directory for keeping track of which monthly updates it already installed. As Metasploit requires, all of the installed exploits go to modules/. My script renames the .rb.txt-files in the packages properly during the installation. NOTE: I'm not touching the Metasploit install directory. The new updates really go to per-user directory and are not available system-wide.

Any bugs, comments and suggestions are welcome. Please drop a comment.

I was trying to see the remote console of one of my servers:

It said: "Could not create token for this session. Max session limit might have reached". This was yet another reminder that Asus iKVM isn't the sharpest tool in the box, it generally responds slowly and sometimes it does weird things. Thanks to Java, it wasn't easy to get the console application running, it said a number of things, including a complaint:

... but after sorting out a number of Java issues it spat out an error-message with XML-content of:

<jnlp spec="1.0+" codebase="http://192.168.1.11/Java">
    <information>
        <title>JViewer</title>
        <vendor>American Megatrends, Inc.</vendor>
        <description kind="one-line">JViewer Console Redirection Application</description>
        <description kind="tooltip">JViewer Console Redirection Application</description>
        <description kind="short"> JViewer enables a user to view the video display of managed
            server via KVM. It also enables the user to redirect his local keyboard, mouse for
            managing the server remotely. </description>
    </information>

...
    <resources>
        <j2se version="1.5+"/>
        <jar href="release/JViewer.jar"/>
    </resources>
    <application-desc>
        <argument>192.168.1.11</argument>
        <argument>7578</argument>
        <argument>
            <html>
                <head>
                    <title>Document Error: Page not found</title>
                </head>
                <body>
                    <h2>Access Error: Page not found</h2>
                    <p>Could not create token for this session. Max session limit might have reached
                    </p>
                </body>
            </html>
        </argument>
    </application-desc>
</jnlp>

I found out somebody who had the same issue at Asus' discussion forums article [Problem]iKVM Remote Control Console w/ Java exception error. There was a suggestion to unplug the power cord. In my case the server is couple hundred kilometers away in a secure data center where I certainly do not have any access. Sure, I could write the support and ask them to do that but ... I'm pretty sure there has to be a way to reset the BMC remotely.

Then I remembered something I did a while ago with ipmitool on Linux-shell. Running:

# ipmitool bmc help
MC Commands:
  reset <warm|cold>
  guid
  info

There is a reset-command in the list. Google led me to an article "Restarting an IBM BMC without restarting the server itself". I wasn't sure what would happen. My first guess was that it would do the same thing as typing "google" into a Google search - the entire world would implode to a singularity. So it is very important not to that. But I really needed the remote console. I was willing to try:

# ipmitool bmc reset cold
Sent cold reset command to MC

Nothing serious happened immediately. The Linux was responsive and world didn't come to an end. After a minute or so, ipmitool bmc info -command yielded a response! The IPMI was back on-line. A logon to web-console:

Yep. I had my console back.

I sure hope that all remote console manufacturers would stop using Java for their apps. It is such a bitch to get a Java application working on after 1.7.0_51 was released. See: "Java 7u51 will not accept JNLP with self-signed certificate?" about other people complaining about that. Anyway, all ended well and I didn't have to drive to the server to do some maintenance.

This topic pops up every once in a while. As default every rendered page implicitly renders a layout too. This is especially bad for JSON or XML or binary responses your application may generate as a response. So far the best explanation and some helpful insights is in Mr. Chris Schreiber's blog scribles.com in the article Disabling Layout in Zend Framework 2.

I was working on a web application, which was a machine-to-machine app and not meant for humans at all. So a layout is completely unnecessary. As Chris instructs, I went directly to the module-class and copy/pasted his code. It failed. He has some sort of typo in the code:

        $sharedEventManager->attach(
                'Zend\Mvc\Controller\AbstractController',
                function(\Zend\Mvc\MvcEvent $event) {

When I was looking for SharedEventManagerInterface PHP-code, it says:

    /**
     * Attach a listener to an event
     *
     * @param  string|array $id Identifier(s) for event emitting
     * @param  string $event
     * @param  callable $callback PHP Callback
     * @param  int $priority Priority at which listener should
     * @return void
     */
    public function attach($id, $event, $callback, $priority = 1);

There clearly are 3 obligatory parameters. Chris' code has three parameters with the optional priority. Something is missing. This is the fix:

       $sharedEventManager->attach(
                MvcEvent::EVENT_DISPATCH,
                'Zend\Mvc\Controller\AbstractController',
                function(\Zend\Mvc\MvcEvent $event) {

Now it works! However, as my application was in its early stages, I was missing the default controller with the class name of IndexController. Adding the code into onBootstrap() didn't help. None of the callback's code was run during event dispatch. More debugging revealed, that my code never triggered the MvcEvent::EVENT_DISPATCH. It did trigger a MvcEvent::EVENT_DISPATCH_ERROR instead. The reason is obvious, I didn't have the class.

For clarity I'll copy/paste my onBootstrap() entirely here:

public function onBootstrap(MvcEvent $evt)
{
    $eventManager = $evt->getApplication()->getEventManager();
    $sharedEventManager = $eventManager->getSharedManager();

    // Make sure layout is not rendered for regular pages
    $sharedEventManager->attach('Zend\Mvc\Controller\AbstractController',
        MvcEvent::EVENT_DISPATCH,
        function (MvcEvent $event) {
            $dispatchResult = $event->getResult();
            if ($dispatchResult instanceof ViewModel) {
                $dispatchResult->setTerminal(true);
            }
        }, -99
    );

    // Make sure layout is not rendered for HTTP/404 pages
    $eventManager->attach(MvcEvent::EVENT_DISPATCH_ERROR,
        function (MvcEvent $event) {
            $dispatchResult = $event->getResult();
            if ($dispatchResult instanceof ViewModel) {
                $dispatchResult->setTerminal(true);
            }
        }, -99
    );
}

Now both events are handled properly, without attempting to find a layout. To test my code, I added a layout/layout.phtml to the project and commented out my above code. It did renader the file contents. Then I removed the comments and deleted the layout/-directory completely. My code still ran on both occasions: when action can be found and when action cannot be found. Actually I also have a CLI-interface to the app, but that won't render the layout anyway.

This is yet another example of the complexity of ZF2. Any trivial task turns out to be a huge pain in the butt. I don't want to start ranting about using PhpRenderer in CLI-app, that's a completely another complaint.

No matter how much I think it, it simply does not make any sense to me. Why an earth, isn't there a button to manually update Adobe Flash Player? What good will it do to download it every single time you want it updated? All the parts are already there in your computer, but there is no reasonable way of telling it to:
Go! Update! Now!

With the help of an excellent tool, Windows Sysinternals Process Explorer, I snooped out the location and parameters of the update application.

On a 64-bit Windows

It is highly likely, that your browser is 32-bit. You need to be some sort of hacker (like me) not to have a 32-bit browser. So, the assumption is this applies to you.

All the good parts are in C:\Windows\SysWOW64\Macromed\Flash\

On a 32-bit Windows

If your PC is old, then you'll have this. (Or, alternate case: you are a hacker and running 64-bit browser.)

All the good stuff is in C:\Windows\System32\Macromed\Flash\

Triggering the update

NOTE:
The version number of the application will change on each update. What I demonstrate here was valid at the time of writing this, but I assure you, the exact name of the application will be something else next month.

The location of the files is ...

For all other browsers than Internet Explorer:

FlashUtil32_12_0_0_43_Plugin.exe -update plugin

For Internet Explorer:

FlashUtil32_12_0_0_44_ActiveX.exe -update activex

Running that command as a regular user will trigger the same process that would be triggered during a Windows login. Since I login rarely, the update almost never triggers for me. I simply put the computer to sleep and wake it up and unlock the screen, which again does not trigger the version check.

This isn't the only stupid thing Adobe does. They don't take your security seriously. Shame on them!