Runtime permission attribution improvements
When an app is proxying access to runtime permission protected data it needs to check whether the calling app has a permission to the data it is about to proxy which leaves a trace in app ops that the requesting app perofmed a data access. However, then the app doing the work needs to get the protected data itself from the OS which access gets attributed only to itself. As a result there are two data accesses in app ops where only the first one is a proxy one that app A got access to Foo through app B - that is the one we want to show in the permission tracking UIs - and one for the data access - that is the one we would want to blame on the calling app, and in fact, these two accesses should be one - that app A accessed Foo though B. This limitation requires fragile one off workarounds where both accesses use the same attribution tag and sys UI has hardcoded rules to dedupe. Since this is not documented we cannot expect that the ecosystem would reliably do this workaround in apps that that the workaround in the OS would be respected by every OEM. This change adds a mechaism to resolve this issue. It allows for an app to create an attribution context for another app and then any private data access thorugh this context would result in a single app op blame that A accessed Foo though B, i.e. we no longer have double accounting. Also this can be nested through apps, e.g. app A asks app B which asks app C for contacts. In this case app B creates an attribution context for app A and calls into app C which creates an attribution context for app B. When app C gets contacts the entire attribution chain would get a porper, single blame: that C accessed the data, that B got the data from C, and that A got the data form B. Furthermore, this mechanism ensures that apps cannot forget to check permissions for the caller before proxying private data. In our example B and C don't need to check the permisisons for A and B, respectively, since the permisisons for the entire attribution chain are checked before data delivery. Attribution chains are not forgeable preventing a bad actor to create an arbitrary one - each attribution is created by the app it refers to and points to a chain of attributions created by their corresponding apps. This change also fixes a bug where all content provider accesses were double counted in app ops due to double noting. While at this it also fixes that apps can now access their own last ops. There was a bug where one could not pass null getting the attributed ops from a historical package ops while this is a valid use case since if there is no attribution everything is mapped to the null tag. There were some app op APIs not being piped thorough the app ops delegate and by extension through the app ops policy. Also now that we have nice way to express the permission chain in a call we no longer need the special casing in activity manager to handle content provider accesses through the OS. Fixed a bug where we don't properly handle the android.os.shell calls with an invlaid tag which was failing while the shell can do any tag. Finally, to ensure the mechanims is validated and works end-to-end we are adding support for a voice recognizer to blame the client app for the mic access. The recognition service can create a blaming context when opening the mic and if the mic is open, which would do all permission checks, we would not do so again. Since changes to PermissionChercker for handling attribution sources were made the CL also hooks up renounced permissoins in the request permission flow and in the permission checks. bug:158792096 bug:180647319 Test:atest CtsPermissionsTestCases atest CtsPermissions2TestCases atest CtsPermissions3TestCases atest CtsPermissions4TestCases atest CtsPermissions5TestCases atest CtsAppOpsTestCases atest CtsAppOps2TestCases Change-Id: Ib04585515d3dc3956966005ae9d94955b2f3ee08
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