# [RFC] deprecate md5_file and sha1_file - Thread: https://externals.io/message/108441 - Original archive: https://news-web.php.net/php.internals/108441 - Started by Tom Van Looy via internals on 2020-02-10T21:49:51+00:00 - Messages: 14 - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #108441 — Tom Van Looy via internals — 2020-02-10T21:49:51+00:00 URL: https://externals.io/message/108441#108441 Hi While in some environments the use of MD5 and SHA1 are still acceptable for some use cases like file integrity verification etc. the use of these algorithms should be discouraged and not be your choice when developing new applications. I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will make people think about upgrading to a better alternative. If you still need this functionality you can always switch to the `hash_file()` function. Carrying around these two dedicated functions seems a bit too much for a modern PHP. What do you think? My feeling was that this is a no brainer. Should I open an RFC for this? Kind regards, Tom Van Looy --- ## #108442 — j adams — 2020-02-10T21:52:42+00:00 URL: https://externals.io/message/108441#108442 · In reply to: #108441 I disagree. While MD5 and SHA1 might not be suitable for modern cryptographic operations, these functions might be needed for legacy situations -- e.g., munging through old data. On Mon, Feb 10, 2020 at 1:50 PM Tom Van Looy via internals < internals@lists.php.net> wrote: > Hi > > While in some environments the use of MD5 and SHA1 are still acceptable for > some use cases like file integrity verification etc. the use of these > algorithms should be discouraged and not be your choice when developing new > applications. > > I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will > make people think about upgrading to a better alternative. If you still > need this functionality you can always switch to the `hash_file()` function. > > Carrying around these two dedicated functions seems a bit too much for a > modern PHP. What do you think? > > My feeling was that this is a no brainer. Should I open an RFC for this? > > Kind regards, > > Tom Van Looy --- ## #108443 — Tom Van Looy via internals — 2020-02-10T21:56:35+00:00 URL: https://externals.io/message/108441#108443 · In reply to: #108442 the `hash_file()` function still supports md5 and sha1 so people that need it should then migrate to hash_file('md5', ...) or hash_file('sha1', ...) instead. That was the idea Kind regards, Tom > I disagree. While MD5 and SHA1 might not be suitable for modern > cryptographic operations, these functions might be needed for legacy > situations -- e.g., munging through old data. > > > On Mon, Feb 10, 2020 at 1:50 PM Tom Van Looy via internals < > internals@lists.php.net> wrote: > > > […] --- ## #108444 — G. P. B. — 2020-02-10T21:57:56+00:00 URL: https://externals.io/message/108441#108444 · In reply to: #108441 On Mon, 10 Feb 2020 at 22:50, Tom Van Looy via internals < internals@lists.php.net> wrote: > Hi > > While in some environments the use of MD5 and SHA1 are still acceptable for > some use cases like file integrity verification etc. the use of these > algorithms should be discouraged and not be your choice when developing new > applications. > > I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will > make people think about upgrading to a better alternative. If you still > need this functionality you can always switch to the `hash_file()` function. > > Carrying around these two dedicated functions seems a bit too much for a > modern PHP. What do you think? > > My feeling was that this is a no brainer. Should I open an RFC for this? > > Kind regards, > > Tom Van Looy > I feel that if we deprecate the file versions of these algorithms we probably should also deprecate the ones which work with plain old strings, namely `md5()` and `sha1()`. [1] [2] It should be noted that these hash functions would still be available through the Hash extension which is always available as of PHP 7.4 as it became a core extension. Depending on how controversial these deprecations are they could be bundled with the big deprecation RFC for PHP 8.0, which is currently in draft. [3] George P. Banyard [1] https://www.php.net/manual/en/function.md5.php [2] https://www.php.net/manual/en/function.sha1.php [3] https://wiki.php.net/rfc/deprecations_php_8_0 --- ## #108445 — Mark Randall — 2020-02-10T22:36:09+00:00 URL: https://externals.io/message/108441#108445 · In reply to: #108441 > I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will > make people think about upgrading to a better alternative. It won't. At best it will make people switch to the hash function. At worst people will not upgrade. If people are using the existing md5 / sha1 algorithms, chances are it's because they're actually wanting to get a hash to compare to something that has already been stored. There's not much point in deprecating the algorithm if we don't eventually plan to remove it, and there is an exactly zero percent chance of it being removed at any point in the next 50 years. Mark Randall --- ## #108446 — Chase Peeler — 2020-02-10T22:42:05+00:00 URL: https://externals.io/message/108441#108446 > > > […] > will > > […] > > It won't. > > At best it will make people switch to the hash function. At worst people > will not upgrade. > > If people are using the existing md5 / sha1 algorithms, chances are it's > because they're actually wanting to get a hash to compare to something > that has already been stored. > > There's not much point in deprecating the algorithm if we don't > eventually plan to remove it, and there is an exactly zero percent > chance of it being removed at any point in the next 50 years. > > Mark Randall > > -- > > > > Why? What does deprecating those two functions do to make PHP a better language? It doesn't add any new features. It doesn't fix any security issues. It doesn't even take away the ability to perform the functionality that they provide, since it still exists in the hash_file function. If you don't like the function, then don't use it. -- Chase Peeler chasepeeler@gmail.com --- ## #108447 — Derick Rethans — 2020-02-10T22:43:48+00:00 URL: https://externals.io/message/108441#108447 · In reply to: #108442 >I disagree. While MD5 and SHA1 might not be suitable for modern >cryptographic operations, these functions might be needed for legacy >situations -- e.g., munging through old data. > > >On Mon, Feb 10, 2020 at 1:50 PM Tom Van Looy via internals < >internals@lists.php.net> wrote: > > > […] >acceptable for > > […] >developing new > > […] >This will > > […] >still > > […] >function. > > […] >for a > > […] >this? > > […] Deprecation doesn't mean immediate removal. It's a nudge to move to something better. Because this deprecation isn't in the last PHP 7, these functions can't be removed until PHP 9. cheers, Derick --- ## #108448 — Tom Van Looy via internals — 2020-02-10T23:04:26+00:00 URL: https://externals.io/message/108441#108448 > > > […] > will > > […] > > It won't. > You can lead a horse to water but you can't make it drink. If this is explained in the upgrade guide, that's all we can do. I would limit the deprecation to these two functions. Not the entire algo's, because indeed that's not going to happen. I give you another case. What if a new user finds only these two functions and starts using them because a sha512_file() etc. does not exist? If the functions are deprecated at least that would be explained in the docs. Tom --- ## #108449 — Stanislav Malyshev — 2020-02-11T05:59:05+00:00 URL: https://externals.io/message/108441#108449 · In reply to: #108441 Hi! > I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will Not sure what's the point of it. SHA1 and MD5 didn't change. The recommendations for their usage has changed, but we generally don't use deprecation warnings to improve users' code and recommend them how to structure their code better. Deprecation is usually for functions that are unsupported (and going to go away) or not having any non-broken uses anymore. We have `crc32()` function which is much less secure than md5 for check-summing obviously, and we don't deprecate it because of that. I don't think we should use deprecations for that purpose. > Carrying around these two dedicated functions seems a bit too much for a > modern PHP. What do you think? There's zero effort expended on "carrying around" these functions, and I don't see why it's "too much" for "modern PHP"? What changed in "modern PHP" that suddenly brought forward the need to minimize the number of existing functions? I don't see any reason for that. On the contrary, deprecating it causes work for people that legitimately use these functions, and makes them either turn off deprecation warnings (unsafe and may lead to real deprecations pass unnoticed) or work around this. I don't think it is beneficial. -- Stas Malyshev smalyshev@gmail.com --- ## #108450 — Stanislav Malyshev — 2020-02-11T06:00:36+00:00 URL: https://externals.io/message/108441#108450 · In reply to: #108443 Hi! > the `hash_file()` function still supports md5 and sha1 so people that need it > should then migrate to hash_file('md5', ...) or hash_file('sha1', ...) > instead. That was the idea This means spending time and effort to cause extra work to people that already have working code with existing PHP and don't need our "help". I don't think we should be doing that. -- Stas Malyshev smalyshev@gmail.com --- ## #108451 — Tom Van Looy via internals — 2020-02-11T06:25:04+00:00 URL: https://externals.io/message/108441#108451 · In reply to: #108449 > Hi! > > > […] > will > > Not sure what's the point of it. SHA1 and MD5 didn't change. The > recommendations for their usage has changed, but we generally don't use > deprecation warnings to improve users' code and recommend them how to > structure their code better. Yes that was my point with "modern php". The recommendation changed. It seems like most people in this discussion like to keep the functions. I didn't expect that. Thanks for the feedback and the arguments all! Tom --- ## #108454 — AllenJB — 2020-02-11T09:34:24+00:00 URL: https://externals.io/message/108441#108454 · In reply to: #108441 As others have mentioned, this will do nothing but make people annoyed and switch to the `hash_file()` version of exactly the same thing or put up another hurdle to updgrading PHP. The password hashing API now provides an obvious go-to for password hashing. For other hashing usages there are, I think, basically two scenarios developers find themselves in: 1) I'm using an API or some other external service and that requires the use of md5 / sha1 - I don't have a choice 2) What do I use instead? Internet searches return "sha1 / md5 is fine for this purpose" or recommend algorithms that aren't natively supported in PHP. The (hash library) documentation does nothing towards helping developers decide what algorithms (or even which hash library functions) they should use for what purposes (and there are a lot of acronyms that many developers are likely to have never encountered that are never explained - HMAC, PBKDF2, HKDF). Yes, of course developers can use third party sources to supplement the information in the manual, but who has time to go seartching for that (esp. when most of the first page on Google probably tells you md5/sha1 is fine anyway)? If you want to change the way developers think about hashing when writing PHP, I would start with the documentation rather than deprecating functions which are essentially aliases and are highly likely used all over the place in cases where they do exactly what people want. AllenJB > Hi > > While in some environments the use of MD5 and SHA1 are still acceptable for > some use cases like file integrity verification etc. the use of these > algorithms should be discouraged and not be your choice when developing new > applications. > > I suggest to deprecated the functions `md5_file()` and `sha1_file()`. This will > make people think about upgrading to a better alternative. If you still > need this functionality you can always switch to the `hash_file()` function. > > Carrying around these two dedicated functions seems a bit too much for a > modern PHP. What do you think? > > My feeling was that this is a no brainer. Should I open an RFC for this? > > Kind regards, > > Tom Van Looy --- ## #108460 — Peter Bowyer — 2020-02-11T11:18:28+00:00 URL: https://externals.io/message/108441#108460 · In reply to: #108454 > If you want to change the way developers think about hashing when > writing PHP, I would start with the documentation rather than > deprecating functions which are essentially aliases and are highly > likely used all over the place in cases where they do exactly what > people want. > I agree. It isn't wrong to use MD5 or SHA1 in the right situation (or even CRC32). The documentation can tell people when they can use these algorithms, and when they must not think about using them. Mark them in the documentation as "RECOMMENDED DO NOT USE" and guide people away. Peter --- ## #108470 — Thomas Hruska — 2020-02-11T12:23:19+00:00 URL: https://externals.io/message/108441#108470 · In reply to: #108446 > > > > […] > Why? What does deprecating those two functions do to make PHP a better > language? It doesn't add any new features. It doesn't fix any security > issues. It doesn't even take away the ability to perform the functionality > that they provide, since it still exists in the hash_file function. > > If you don't like the function, then don't use it. I'd be fine with someone just adding a Warning to the documentation that MD5 and SHA-1 are known broken hashing algorithms when used for *cryptographic/security* purposes. The algorithms and related functions are completely fine though for other purposes such as detecting single-bit changes in file data where something a little more robust than CRC32 is needed but don't want to waste a lot of storage space. `md5()` and `sha1()` already have basic warnings applied. -- Thomas Hruska CubicleSoft President I've got great, time saving software that you will find useful. http://cubiclesoft.com/ And once you find my software useful: http://cubiclesoft.com/donate/