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path: root/apt-pkg/acquire-item.h
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2016-06-22add insecure (and weak) allow-options for sources.listDavid Kalnischkies
Weak had no dedicated option before and Insecure and Downgrade were both global options, which given the effect they all have on security is rather bad. Setting them for individual repositories only isn't great but at least slightly better and also more consistent with other settings for repositories.
2016-05-07don't construct MetaIndex acquire items with IndexTargetsDavid Kalnischkies
We don't have to initialize the Release files with a set of IndexTargets to acquire, but instead wait for the Release file to be acquired and only then ask which IndexTargets to get. Git-Dch: Ignore
2016-05-07delay progress until Release files are downloadedDavid Kalnischkies
Progress reporting used an "upper bound" on files we might get, expect that this wasn't correct in case pdiff entered the picture. So instead of calculating a value which is perhaps incorrect, we just accept that we can't tell how many files we are going to download and just keep at 0% until we know. Additionally, if we have pdiffs we wait until we got these (sub)index files, too. That could all be done better by downloading all Release files first and planing with them in hand accordingly, but one step at a time.
2016-05-07TransactionManager can never be a nullptrDavid Kalnischkies
The code naturally evolved from a TransactionManager optional to a required setup which resulted in various places doing unneeded checks suggesting a more complicated setup than is actually needed. Git-Dch: Ignore
2016-04-25use the same redirection mirror for all index filesDavid Kalnischkies
Redirection services like httpredir.debian.org tend to use a set of mirrors from which they pick a mirror at "random" for each requested file, which is usually benefitial for the download of debs, but for the index files this can quickly cause problems (aka hashsum mismatches) if the two (or more) mirrors involved are only slightly out-of-sync. This commit "resolves" this issue by using the mirror we ended up using to get the (signed) Release file directly to get the index files belonging to this Release file instead of asking the redirection service which eliminates the risk of hitting out-of-sync mirrors. As an obvious downside the redirection service can't serve partial mirrors anymore for indexes and the download of indexes indexed in the same Release file can't be done in parallel (from different mirrors). This does not effect the download of non-index files like deb-files as out-of-sync mirrors aren't a huge problem there, so the parallel download outweights a potentially 404 error (also because this causes no errenous downloads while hashsum mismatches download the entire file before finding out that it was pointless). The rational for this is that indexes are relative to the Release file. If we would be talking about a HTML page including images, such a behaviour is obvious and intended – not doing it means in the best case a bunch of "useless" requests which will all be answered with a redirect.
2016-04-25show more details for "Hash Sum mismatch" errorsDavid Kalnischkies
Users tend to report these errors with just this error message… not very actionable and hard to figure out if this is a temporary or 'permanent' mirror-sync issue or even the occasional apt bug. Showing the involved hashsums and modification times should help in triaging these kind of bugs – and eventually we will have less of them via by-hash. The subheaders aren't marked for translation for now as they are technical glibberish and probably easier to deal with if not translated. After all, our iconic "Hash Sum mismatch" is translated at least. These additions were proposed in #817240 by Peter Palfrader.
2016-04-25sanify unused ReportMirrorFailure a tiny bitDavid Kalnischkies
Calling the (non-existent) reporter multiple times for the same error with different codes for the same error (e.g. hashsum) is a bit strange. It also doesn't need to be a public API. Ideally that would all look and behave slightly different, but we will worry about that at the time this is actually (planed to be) used somewhere… Git-Dch: Ignore
2016-04-07ensure transaction states are changed only onceDavid Kalnischkies
We want to keep track of the state of a transaction overall to base future decisions on it, but as a pre-requirement we have to make sure that a transaction isn't commited twice (which happened if the download of InRelease failed and Release takes over). It also happened to create empty commits after a transaction was already aborted in cases in which the Release files were rejected. This isn't effecting security at the moment, but to ensure this isn't happening again and can never be bad a bunch of fatal error messages are added to make regressions on this front visible.
2016-02-11always download changelogs into /tmp firstDavid Kalnischkies
pkgAcqChangelog has the default behaviour of downloading a changelog to a temporary directory (inside /tmp, not /tmp directly), which is cleaned up on shutdown, but this can be overridden to store the changelog more permanently – but that caries a permission problem. For changelog we can 'easily' solve this by always downloading to a temporary directory and only move it out of there on done.
2016-01-08keep compressed indexes in a low-cost formatDavid Kalnischkies
Downloading and storing are two different operations were different compression types can be preferred. For downloading we provide the choice via Acquire::CompressionTypes::Order as there is a choice to be made between download size and speed – and limited by whats available in the repository. Storage on the other hand has all compressions currently supported by apt available and to reduce runtime of tools accessing these files the compression type should be a low-cost format in terms of decompression. apt traditionally stores its indexes uncompressed on disk, but has options to keep them compressed. Now that apt downloads additional files we also deal with files which simply can't be stored uncompressed as they are just too big (like Contents for apt-file). Traditionally they are downloaded in a low-cost format (gz) as repositories do not provide other formats, but there might be even lower-cost formats and for download we could introduce higher-cost in the repositories. Downloading an entire index potentially requires recompression to another format, so an update takes potentially longer – but big files are usually updated via pdiffs which has to de- and re-compress anyhow and does it on the fly anyhow, so there is no extra time needed and in general it seems to be benefitial to invest the time in update to save time later on file access.
2016-01-08allow pdiff bootstrap from all supported compressorsDavid Kalnischkies
There is no reason to enforce that the file we start the bootstrap with is compressed with a compressor which is available online. This allows us to change the on-disk format as well as deals with repositories adding/removing support for a specific compressor.
2015-12-02use @CHANGEPATH@ as placeholder in changelog URI templatesDavid Kalnischkies
This should make it more obvious that CHANGEPATH is a placeholder which apt will replace with a package specific path rather than a string constant. Mail-Reference: <87d1upgvaf.fsf@deep-thought.43-1.org> Mail-Archive: https://lists.debian.org/debian-dak/2015/12/msg00005.html
2015-11-27add messages to our deprecation warnings in libaptDavid Kalnischkies
Git-Dch: Ignore
2015-08-28implement PDiff patching for compressed filesDavid Kalnischkies
Some additional files like 'Contents' are very big and should therefore kept compressed on the disk, which apt-file did in the past. It also implemented pdiff patching of these files by un- and recompressing these files on-the-fly, with this commit we can do the same – but we can do this in both pdiff patching styles (client and server merging) and secured by hashes. Hashes are in so far slightly complicated as we can't compare the hashes of the compressed files as we might compress them differently than the server would (different compressor versions, options, …), so we must compare the hashes of the uncompressed content. While this commit has changes in public headers, the classes it changes are marked as hidden, so nobody can use them directly, which means the ABI break is internal only.
2015-08-10enhance "hit paywall" error message to mention the probable causeDavid Kalnischkies
Reporting errors from Done() is bad for progress reporting and such, so factoring this out is a good idea and we start with moving the supposed- to-be clearsigned file isn't clearsigned out first – improving the error message in the process as we use the same message for a similar case (NODATA) as this is what I have to look at with the venue wifi at DebCamp and the old errormessage doesn't really say anything.
2015-08-10add c++11 override marker to overridden methodsDavid Kalnischkies
C++11 adds the 'override' specifier to mark that a method is overriding a base class method and error out if not. We hide it in the APT_OVERRIDE macro to ensure that we keep compiling in pre-c++11 standards. Reported-By: clang-modernize -add-override -override-macros Git-Dch: Ignore
2015-08-10remove the longtime deprecated vendor{,list} stuffDavid Kalnischkies
History suggests that this comes from an earlier apt-secure implementation, but never really became a thing, totally unused and marked as deprecated for "ages" now. Especially as it did nothing even if it would have been used (libapt itself didn't use it at all).
2015-08-10implement Signed-By option for sources.listDavid Kalnischkies
Limits which key(s) can be used to sign a repository. Not immensely useful from a security perspective all by itself, but if the user has additional measures in place to confine a repository (like pinning) an attacker who gets the key for such a repository is limited to its potential and can't use the key to sign its attacks for an other (maybe less limited) repository… (yes, this is as weak as it sounds, but having the capability might come in handy for implementing other stuff later).
2015-08-10merge indexRecords into metaIndexDavid Kalnischkies
indexRecords was used to parse the Release file – mostly the hashes – while metaIndex deals with downloading the Release file, storing all indexes coming from this release and … parsing the Release file, but this time mostly for the other fields. That wasn't a problem in metaIndex as this was done in the type specific subclass, but indexRecords while allowing to override the parsing method did expect by default a specific format. APT isn't really supporting different types at the moment, but this is a violation of the abstraction we have everywhere else and, which is the actual reason for this merge: Options e.g. coming from the sources.list come to metaIndex naturally, which needs to wrap them up and bring them into indexRecords, so the acquire system is told about it as they don't get to see the metaIndex, but they don't really belong in indexRecords as this is just for storing data loaded from the Release file… the result is a complete mess. I am not saying it is a lot prettier after the merge, but at least adding new options is now slightly easier and there is just one place responsible for parsing the Release file. That can't hurt.
2015-08-10fix memory leaks reported by -fsanitizeDavid Kalnischkies
Various small leaks here and there. Nothing particularily big, but still good to fix. Found by the sanitizers while running our testcases. Reported-By: gcc -fsanitize Git-Dch: Ignore
2015-08-10make all d-pointer * const pointersDavid Kalnischkies
Doing this disables the implicit copy assignment operator (among others) which would cause hovac if used on the classes as it would just copy the pointer, not the data the d-pointer points to. For most of the classes we don't need a copy assignment operator anyway and in many classes it was broken before as many contain a pointer of some sort. Only for our Cacheset Container interfaces we define an explicit copy assignment operator which could later be implemented to copy the data from one d-pointer to the other if we need it. Git-Dch: Ignore
2015-08-10apply various style suggestions by cppcheckDavid Kalnischkies
Some of them modify the ABI, but given that we prepare a big one already, these few hardly count for much. Git-Dch: Ignore
2015-06-16add d-pointer, virtual destructors and de-inline de/constructorsDavid Kalnischkies
To have a chance to keep the ABI for a while we need all three to team up. One of them missing and we might loose, so ensuring that they are available is a very tedious but needed task once in a while. Git-Dch: Ignore
2015-06-15deal better with acquiring the same URI multiple timesDavid Kalnischkies
This is an unlikely event for indexes and co, but it can happen quiet easily e.g. for changelogs where you want to get the changelogs for multiple binary package(version)s which happen to all be built from a single source. The interesting part is that the Acquire system actually detected this already and set the item requesting the URI again to StatDone - expect that this is hardly sufficient: an Item must be Complete=true as well to be considered truely done and that is only the tip of the ::Done handling iceberg. So instead of this StatDone hack we allow QItems to be owned by multiple items and notify all owners about everything now, so that for the point of each item they got it downloaded just for them.
2015-06-15provide a public interface for acquiring changelogsDavid Kalnischkies
Provided is a specialized acquire item which given a version can figure out the correct URI to try by itself and if not provides an error message alongside with static methods to get just the URI it would try to download if it should just be displayed or similar such. The URI is constructed as follows: Release files can provide an URI template in the "Changelogs" field, otherwise we lookup a configuration item based on the "Label" or "Origin" of the Release file to get a (hopefully known) default value for now. This template should contain the string CHANGEPATH which is replaced with the information about the version we want the changelog for (e.g. main/a/apt/apt_1.1). This middleway was choosen as this path part was consistent over the three known implementations (+1 defunct), while the rest of the URI varies widely between them. The benefit of this construct is that it is now easy to get changelogs for Debian packages on Ubuntu and vice versa – even at the moment where the Changelogs field is present nowhere. Strictly better than what apt-get had before as it would even fail to get changelogs from security… Now it will notice that security identifies as Origin: Debian and pick this setting (assuming again that no Changelogs field exists). If on the other hand security would ship its changelogs in a different location we could set it via the Label option overruling Origin. Closes: 687147, 739854, 784027, 787190
2015-06-11use IndexTarget to get to IndexFileDavid Kalnischkies
Removes a bunch of duplicated code in the deb-specific parts. Especially the Description part is now handled centrally by IndexTarget instead of being duplicated to the derivations of IndexFile. Git-Dch: Ignore
2015-06-10stop using IndexTarget pointers which are never freedDavid Kalnischkies
Creating and passing around a bunch of pointers of IndexTargets (and of a vector of pointers of IndexTargets) is probably done to avoid the 'costly' copy of container, but we are really not in a timecritical operation here and move semantics will help us even further in the future. On the other hand we never do a proper cleanup of these pointers, which is very dirty, even if structures aren't that big… The changes will effecting many items only effect our own hidden class, so we can do that without fearing breaking interfaces or anything. Git-Dch: Ignore
2015-06-10store all targets data in IndexTarget structDavid Kalnischkies
We still need an API for the targets, so slowly prepare the IndexTargets to let them take this job. Git-Dch: Ignore
2015-06-09remove debianism file-content verificationDavid Kalnischkies
The code requires every index file we download to have a Package field, but that doesn't hold true for all index we might want to download in the future. Some might not even be deb822 formatted files… The check was needed as apt used to accept unverifiable files like Translation-*, but nowadays it requires hashes for these as well. Even for unsigned repositories we interpret the Release file as binding now, which means this check isn't triggerable expect for repositories which do not have a Release file at all – something which is highly discouraged! Git-Dch: Ignore
2015-06-09cleanup pdiff support detection decisionDavid Kalnischkies
Its a bit unclean to create an item just to let the item decide that it can't do anything and let it fail, so instead we let the item creator decide in all cases if patching should be attempted. Also pulls a small trick to get the hashes for the current file without calculating them by looking at the 'old' Release file if we have it. Git-Dch: Ignore
2015-06-09support hashes for compressed pdiff filesDavid Kalnischkies
At the moment we only have hashes for the uncompressed pdiff files, but via the new '$HASH-Download' field in the .diff/Index hashes can be provided for the .gz compressed pdiff file, which apt will pick up now and use to verify the download. Now, we "just" need a buy in from the creators of repositories…
2015-06-09check patch hashes in rred worker instead of in the handlerDavid Kalnischkies
rred is responsible for unpacking and reading the patch files in one go, but we currently only have hashes for the uncompressed patch files, so the handler read the entire patch file before dispatching it to the worker which would read it again – both with an implicit uncompress. Worse, while the workers operate in parallel the handler is the central orchestration unit, so having it busy with work means the workers do (potentially) nothing. This means rred is working with 'untrusted' data, which is bad. Yet, having the unpack in the handler meant that the untrusted uncompress was done as root which isn't better either. Now, we have it at least contained in a binary which we can harden a bit better. In the long run, we want hashes for the compressed patch files through to be safe.
2015-06-09rework hashsum verification in the acquire systemDavid Kalnischkies
Having every item having its own code to verify the file(s) it handles is an errorprune process and easy to break, especially if items move through various stages (download, uncompress, patching, …). With a giant rework we centralize (most of) the verification to have a better enforcement rate and (hopefully) less chance for bugs, but it breaks the ABI bigtime in exchange – and as we break it anyway, it is broken even harder. It shouldn't effect most frontends as they don't deal with the acquire system at all or implement their own items, but some do and will need to be patched (might be an opportunity to use apt on-board material). The theory is simple: Items implement methods to decide if hashes need to be checked (in this stage) and to return the expected hashes for this item (in this stage). The verification itself is done in worker message passing which has the benefit that a hashsum error is now a proper error for the acquire system rather than a Done() which is later revised to a Failed().
2015-05-18treat older Release files than we already have as an IMSHitDavid Kalnischkies
Valid-Until protects us from long-living downgrade attacks, but not all repositories have it and an attacker could still use older but still valid files to downgrade us. While this makes it sounds like a security improvement now, its a bit theoretical at best as an attacker with capabilities to pull this off could just as well always keep us days (but in the valid period) behind and always knows which state we have, as we tell him with the If-Modified-Since header. This is also why this is 'silently' ignored and treated as an IMSHit rather than screamed at the user as this can at best be an annoyance for attackers. An error here would 'regularily' be encountered by users by out-of-sync mirrors serving a single run (e.g. load balancer) or in two consecutive runs on the other hand, so it would just help teaching people ignore it. That said, most of the code churn is caused by enforcing this additional requirement. Crisscross from InRelease to Release.gpg is e.g. very unlikely in practice, but if we would ignore it an attacker could sidestep it this way.
2015-05-13detect Releasefile IMS hits even if the server doesn'tDavid Kalnischkies
Not all servers we are talking to support If-Modified-Since and some are not even sending Last-Modified for us, so in an effort to detect such hits we run a hashsum check on the 'old' compared to the 'new' file, we got the hashes for the 'new' already for "free" from the methods anyway and hence just need to calculated the old ones. This allows us to detect hits even with unsupported servers, which in turn means we benefit from all the new hit behavior also here.
2015-05-11improve partial/ cleanup in abort and failure casesDavid Kalnischkies
Especially pdiff-enhanced downloads have the tendency to fail for various reasons from which we can recover and even a successful download used to leave the old unpatched index in partial/. By adding a new method responsible for making the transaction of an individual file happen we can at specialisations especially for abort cases to deal with the cleanup. This also helps in keeping the compressed indexes around if another index failed instead of keeping the decompressed files, which we wouldn't pick up in the next call.
2015-04-19a hit on Release files means the indexes will be hits tooDavid Kalnischkies
If we get a IMSHit for the Transaction-Manager (= the InRelease file or as its still supported fallback Release + Release.gpg combo) we can assume that every file we would queue based on this manager, but already have locally is current and hence would get an IMSHit, too. We therefore save us and the server the trouble and skip the queuing in this case. Beside speeding up repetative executions of 'apt-get update' this way we also avoid hitting hashsum errors if the indexes are in fact already updated, but the Release file isn't yet as it is the case on well behaving mirrors as Release files is updated last. The implementation is a bit harder than the theory makes it sound as we still have to keep reverifying the Release files (e.g. to detect now expired once to avoid an attacker being able to silently stale us) and have to handle cases in which the Release file hits, but some indexes aren't present (e.g. user added a new foreign architecture).
2015-04-19refactor calculation of final lists/ name from URIDavid Kalnischkies
Calculating the final name of an item which it will have after everything is done and verified successfully is suprisingly complicated as while they all follow a simple pattern, the URI and where it is stored varies between the items. With some (abibreaking) redesign we can abstract this similar to how it is already down for the partial file location. Git-Dch: Ignore
2014-11-08guard const-ification API changesDavid Kalnischkies
Git-Dch: Ignore
2014-11-08mark internal interfaces as hiddenDavid Kalnischkies
We have a bunch of classes which are of no use for the outside world, but were still exported and so needed to preserve ABI/API. Marking them as hidden to not export them any longer is a big API break in theory, but in practice nobody is using them – as if they would its a bug.
2014-11-06Merge remote-tracking branch 'upstream/debian/experimental' into ↵Michael Vogt
feature/no-more-acquire-guessing Conflicts: apt-pkg/acquire-item.cc
2014-11-04apt-pkg/acquire-item.h: make friend declaration compatible with older gccMichael Vogt
2014-11-04Call "Dequeue()" for items in AbortTransaction() to fix raceMichael Vogt
The pkgAcquire::Run() code works uses a while(ToFetch > 0) loop over the items queued for fetching. This means that we need to Deqeueue the item if we call AbortTransaction() to avoid a hang.
2014-10-29Only support Translation-* that are listed in the {In,}Release fileMichael Vogt
Handle Translation-* files exactly like Packages files (with the expection that it is ok if a download of them fails). Remove all "guessing" on apts side. This will elimimnate a bunch of errors releated to captive portals and similar. Its also more correct and removes another potential attack vector.
2014-10-23chown finished partial files earlierDavid Kalnischkies
partial files are chowned by the Item baseclass to let the methods work with them. Now, this baseclass is also responsible for chowning the files back to root instead of having various deeper levels do this. The consequence is that all overloaded Failed() methods now call the Item::Failed base as their first step. The same is done for Done(). The effect is that even in partial files usually don't belong to _apt anymore, helping sneakernets and reducing possibilities of a bad method modifying files not belonging to them. The change is supported by the framework not only supporting being run as root, but with proper permission management, too, so that privilege dropping can be tested with them.
2014-10-07Add new Acquire::MaxReleaseFileSize=10*1000*1000 optionMichael Vogt
This option controls the maximum size of Release/Release.gpg/InRelease files. The rational is that we do not know the size of these files in advance and we want to protect against a denial of service attack where someone sends us endless amounts of data until the disk is full (we do know the size all other files (Packages/Sources/debs)).
2014-10-07Merge remote-tracking branch 'upstream/debian/experimental' into ↵Michael Vogt
feature/acq-trans Conflicts: apt-pkg/acquire-item.cc
2014-10-07use _apt:root only for partial directoriesDavid Kalnischkies
Using a different user for calling methods is intended to protect us from methods running amok (via remotely exploited bugs) by limiting what can be done by them. By using root:root for the final directories and just have the files in partial writeable by the methods we enhance this in sofar as a method can't modify already verified data in its parent directory anymore. As a side effect, this also clears most of the problems you could have if the final directories are shared without user-sharing or if these directories disappear as they are now again root owned and only the partial directories contain _apt owned files (usually none if apt isn't running) and the directory itself is autocreated with the right permissions.
2014-10-06rename StopAuthentication -> CheckStopAuthentication and make it protectedMichael Vogt
2014-10-06rename AuthDone() -> CheckAuthDone()Michael Vogt