Add AID for PRNG seeder daemon.
Also adjust permissions on /dev/hw_random to allow prng_seeder group
read access.
Manual testing protocol:
* Verify prng_seeder daemon is running and has the
correct label and uid/gid.
* Verify prng_seeder socket present and has correct
label and permissions
* Verify no SELinux denials
* strace a libcrypto process and verify it reads seeding
data from prng_seeder (e.g. strace bssl rand -hex 1024)
* strace seeder daemon to observe incoming connections
(e.g. strace -f -p `pgrep prng_seeder`)
* Kill daemon, observe that init restarts it
* strace again and observe clients now seed from new instance
Bug: 243933553
Test: Manual - see above
Change-Id: I4d526844b232fc2a1fa5ffd701ca5bc5c09e7e96
Merged-In: I4d526844b232fc2a1fa5ffd701ca5bc5c09e7e96
(cherry picked from commit 6cb61610e619e31bd22c12895ec0ca623f793127)
diff --git a/libcutils/include/private/android_filesystem_config.h b/libcutils/include/private/android_filesystem_config.h
index bdb8075..0030887 100644
--- a/libcutils/include/private/android_filesystem_config.h
+++ b/libcutils/include/private/android_filesystem_config.h
@@ -138,6 +138,7 @@
#define AID_JC_IDENTITYCRED 1089 /* Javacard Identity Cred HAL - to manage omapi ARA rules */
#define AID_SDK_SANDBOX 1090 /* SDK sandbox virtual UID */
#define AID_SECURITY_LOG_WRITER 1091 /* write to security log */
+#define AID_PRNG_SEEDER 1092 /* PRNG seeder daemon */
/* Changes to this file must be made in AOSP, *not* in internal branches. */
#define AID_SHELL 2000 /* adb and debug shell user */
diff --git a/rootdir/ueventd.rc b/rootdir/ueventd.rc
index a140c8c..4ec59af 100644
--- a/rootdir/ueventd.rc
+++ b/rootdir/ueventd.rc
@@ -37,6 +37,8 @@
/dev/tty 0666 root root
/dev/random 0666 root root
/dev/urandom 0666 root root
+# Aside from kernel threads, only prng_seeder needs access to HW RNG
+/dev/hw_random 0400 prng_seeder prng_seeder
/dev/ashmem* 0666 root root
/dev/binder 0666 root root
/dev/hwbinder 0666 root root