Merge changes If530edaf,I7f11a135,I28412f24,Ia27a61fa,If221e239 into main am: f15785a54d am: 56e7c29466 am: 24a5445880

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/2777079

Change-Id: I8cfec06342f3c41e1b0f078003206cca8abf3689
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

3 files changed, 20 insertions, 141 deletions

diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index ecb3c816..45b062d6 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -482,17 +482,6 @@ static bool load_all_de_keys() {
     return true;
 }
 
-// Attempt to reinstall CE keys for users that we think are unlocked.
-static bool try_reload_ce_keys() {
-    for (const auto& [user_id, user_policies] : s_ce_policies) {
-        if (!android::vold::reloadKeyFromSessionKeyring(DATA_MNT_POINT, user_policies.internal)) {
-            LOG(ERROR) << "Failed to load CE key from session keyring for user " << user_id;
-            return false;
-        }
-    }
-    return true;
-}
-
 bool fscrypt_initialize_systemwide_keys() {
     LOG(INFO) << "fscrypt_initialize_systemwide_keys";
 
@@ -621,13 +610,6 @@ bool fscrypt_init_user0() {
         return false;
     }
 
-    // In some scenarios (e.g. userspace reboot) we might unmount userdata
-    // without doing a hard reboot. If CE keys were stored in fs keyring then
-    // they will be lost after unmount. Attempt to re-install them.
-    if (IsFbeEnabled() && android::vold::isFsKeyringSupported()) {
-        if (!try_reload_ce_keys()) return false;
-    }
-
     fscrypt_init_user0_done = true;
     return true;
 }
diff --git a/KeyUtil.cpp b/KeyUtil.cpp
index 5a8b5503..9e8920d1 100644
--- a/KeyUtil.cpp
+++ b/KeyUtil.cpp
@@ -164,7 +164,7 @@ static bool fscryptKeyring(key_serial_t* device_keyring) {
     return true;
 }
 
-// Add an encryption key of type "logon" to the global session keyring.
+// Add an encryption key to the legacy global session keyring.
 static bool installKeyLegacy(const KeyBuffer& key, const std::string& raw_ref) {
     // Place fscrypt_key into automatically zeroing buffer.
     KeyBuffer fsKeyBuffer(sizeof(fscrypt_key));
@@ -187,32 +187,6 @@ static bool installKeyLegacy(const KeyBuffer& key, const std::string& raw_ref) {
     return true;
 }
 
-// Installs fscrypt-provisioning key into session level kernel keyring.
-// This allows for the given key to be installed back into filesystem keyring.
-// For more context see reloadKeyFromSessionKeyring.
-static bool installProvisioningKey(const KeyBuffer& key, const std::string& ref,
-                                   const fscrypt_key_specifier& key_spec) {
-    key_serial_t device_keyring;
-    if (!fscryptKeyring(&device_keyring)) return false;
-
-    // Place fscrypt_provisioning_key_payload into automatically zeroing buffer.
-    KeyBuffer buf(sizeof(fscrypt_provisioning_key_payload) + key.size(), 0);
-    fscrypt_provisioning_key_payload& provisioning_key =
-            *reinterpret_cast<fscrypt_provisioning_key_payload*>(buf.data());
-    memcpy(provisioning_key.raw, key.data(), key.size());
-    provisioning_key.type = key_spec.type;
-
-    key_serial_t key_id = add_key("fscrypt-provisioning", ref.c_str(), (void*)&provisioning_key,
-                                  buf.size(), device_keyring);
-    if (key_id == -1) {
-        PLOG(ERROR) << "Failed to insert fscrypt-provisioning key for " << ref
-                    << " into session keyring";
-        return false;
-    }
-    LOG(DEBUG) << "Added fscrypt-provisioning key for " << ref << " to session keyring";
-    return true;
-}
-
 // Build a struct fscrypt_key_specifier for use in the key management ioctls.
 static bool buildKeySpecifier(fscrypt_key_specifier* spec, const EncryptionPolicy& policy) {
     switch (policy.options.version) {
@@ -240,34 +214,6 @@ static bool buildKeySpecifier(fscrypt_key_specifier* spec, const EncryptionPolic
     }
 }
 
-// Installs key into keyring of a filesystem mounted on |mountpoint|.
-//
-// It's callers responsibility to fill key specifier, and either arg->raw or arg->key_id.
-//
-// In case arg->key_spec.type equals to FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER
-// arg->key_spec.u.identifier will be populated with raw key reference generated
-// by kernel.
-//
-// For documentation on difference between arg->raw and arg->key_id see
-// https://www.kernel.org/doc/html/latest/filesystems/fscrypt.html#fs-ioc-add-encryption-key
-static bool installFsKeyringKey(const std::string& mountpoint, const EncryptionOptions& options,
-                                fscrypt_add_key_arg* arg) {
-    if (options.use_hw_wrapped_key) arg->__flags |= __FSCRYPT_ADD_KEY_FLAG_HW_WRAPPED;
-
-    android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
-    if (fd == -1) {
-        PLOG(ERROR) << "Failed to open " << mountpoint << " to install key";
-        return false;
-    }
-
-    if (ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, arg) != 0) {
-        PLOG(ERROR) << "Failed to install fscrypt key to " << mountpoint;
-        return false;
-    }
-
-    return true;
-}
-
 bool installKey(const std::string& mountpoint, const EncryptionOptions& options,
                 const KeyBuffer& key, EncryptionPolicy* policy) {
     const std::lock_guard<std::mutex> lock(fscrypt_keyring_mutex);
@@ -304,24 +250,33 @@ bool installKey(const std::string& mountpoint, const EncryptionOptions& options,
             return false;
     }
 
+    if (options.use_hw_wrapped_key) arg->__flags |= __FSCRYPT_ADD_KEY_FLAG_HW_WRAPPED;
+    // Provide the raw key.
     arg->raw_size = key.size();
     memcpy(arg->raw, key.data(), key.size());
 
-    if (!installFsKeyringKey(mountpoint, options, arg)) return false;
+    android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+    if (fd == -1) {
+        PLOG(ERROR) << "Failed to open " << mountpoint << " to install key";
+        return false;
+    }
+
+    if (ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, arg) != 0) {
+        PLOG(ERROR) << "Failed to install fscrypt key to " << mountpoint;
+        return false;
+    }
 
     if (arg->key_spec.type == FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER) {
         // Retrieve the key identifier that the kernel computed.
         policy->key_raw_ref =
                 std::string((char*)arg->key_spec.u.identifier, FSCRYPT_KEY_IDENTIFIER_SIZE);
     }
-    std::string ref = keyrefstring(policy->key_raw_ref);
-    LOG(DEBUG) << "Installed fscrypt key with ref " << ref << " to " << mountpoint;
-
-    if (!installProvisioningKey(key, ref, arg->key_spec)) return false;
+    LOG(DEBUG) << "Installed fscrypt key with ref " << keyrefstring(policy->key_raw_ref) << " to "
+               << mountpoint;
     return true;
 }
 
-// Remove an encryption key of type "logon" from the global session keyring.
+// Remove an encryption key from the legacy global session keyring.
 static bool evictKeyLegacy(const std::string& raw_ref) {
     key_serial_t device_keyring;
     if (!fscryptKeyring(&device_keyring)) return false;
@@ -344,26 +299,6 @@ static bool evictKeyLegacy(const std::string& raw_ref) {
     return success;
 }
 
-static bool evictProvisioningKey(const std::string& ref) {
-    key_serial_t device_keyring;
-    if (!fscryptKeyring(&device_keyring)) {
-        return false;
-    }
-
-    auto key_serial = keyctl_search(device_keyring, "fscrypt-provisioning", ref.c_str(), 0);
-    if (key_serial == -1 && errno != ENOKEY) {
-        PLOG(ERROR) << "Error searching session keyring for fscrypt-provisioning key for " << ref;
-        return false;
-    }
-
-    if (key_serial != -1 && keyctl_unlink(key_serial, device_keyring) != 0) {
-        PLOG(ERROR) << "Failed to unlink fscrypt-provisioning key for " << ref
-                    << " from session keyring";
-        return false;
-    }
-    return true;
-}
-
 static void waitForBusyFiles(const struct fscrypt_key_specifier key_spec, const std::string ref,
                              const std::string mountpoint) {
     android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
@@ -462,8 +397,6 @@ bool evictKey(const std::string& mountpoint, const EncryptionPolicy& policy) {
         std::thread busyFilesThread(waitForBusyFiles, arg.key_spec, ref, mountpoint);
         busyFilesThread.detach();
     }
-
-    if (!evictProvisioningKey(ref)) return false;
     return true;
 }
 
@@ -485,31 +418,5 @@ bool retrieveOrGenerateKey(const std::string& key_path, const std::string& tmp_p
     return true;
 }
 
-bool reloadKeyFromSessionKeyring(const std::string& mountpoint, const EncryptionPolicy& policy) {
-    key_serial_t device_keyring;
-    if (!fscryptKeyring(&device_keyring)) {
-        return false;
-    }
-
-    std::string ref = keyrefstring(policy.key_raw_ref);
-    auto key_serial = keyctl_search(device_keyring, "fscrypt-provisioning", ref.c_str(), 0);
-    if (key_serial == -1) {
-        PLOG(ERROR) << "Failed to find fscrypt-provisioning key for " << ref
-                    << " in session keyring";
-        return false;
-    }
-
-    LOG(DEBUG) << "Installing fscrypt-provisioning key for " << ref << " back into " << mountpoint
-               << " fs-keyring";
-
-    struct fscrypt_add_key_arg arg;
-    memset(&arg, 0, sizeof(arg));
-    if (!buildKeySpecifier(&arg.key_spec, policy)) return false;
-    arg.key_id = key_serial;
-    if (!installFsKeyringKey(mountpoint, policy.options, &arg)) return false;
-
-    return true;
-}
-
 }  // namespace vold
 }  // namespace android
diff --git a/KeyUtil.h b/KeyUtil.h
index 5940b8a8..17a234e6 100644
--- a/KeyUtil.h
+++ b/KeyUtil.h
@@ -49,16 +49,11 @@ bool isFsKeyringSupported(void);
 // on the specified filesystem using the specified encryption policy version.
 //
 // For v1 policies, we use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it.
-// Otherwise we add the key to the global session keyring as a "logon" key.
+// Otherwise we add the key to the legacy global session keyring.
 //
 // For v2 policies, we always use FS_IOC_ADD_ENCRYPTION_KEY; it's the only way
 // the kernel supports.
 //
-// If kernel supports FS_IOC_ADD_ENCRYPTION_KEY, also installs key of
-// fscrypt-provisioning type to the global session keyring. This makes it
-// possible to unmount and then remount mountpoint without losing the file-based
-// key.
-//
 // Returns %true on success, %false on failure.  On success also sets *policy
 // to the EncryptionPolicy used to refer to this key.
 bool installKey(const std::string& mountpoint, const android::fscrypt::EncryptionOptions& options,
@@ -66,10 +61,10 @@ bool installKey(const std::string& mountpoint, const android::fscrypt::Encryptio
 
 // Evict a file-based encryption key from the kernel.
 //
-// This undoes the effect of installKey().
+// We use FS_IOC_REMOVE_ENCRYPTION_KEY if the kernel supports it.  Otherwise we
+// remove the key from the legacy global session keyring.
 //
-// If the kernel doesn't support the filesystem-level keyring, the caller is
-// responsible for dropping caches.
+// In the latter case, the caller is responsible for dropping caches.
 bool evictKey(const std::string& mountpoint, const android::fscrypt::EncryptionPolicy& policy);
 
 // Retrieves the key from the named directory, or generates it if it doesn't
@@ -78,11 +73,6 @@ bool retrieveOrGenerateKey(const std::string& key_path, const std::string& tmp_p
                            const KeyAuthentication& key_authentication, const KeyGeneration& gen,
                            KeyBuffer* key);
 
-// Re-installs a file-based encryption key of fscrypt-provisioning type from the
-// global session keyring back into fs keyring of the mountpoint.
-bool reloadKeyFromSessionKeyring(const std::string& mountpoint,
-                                 const android::fscrypt::EncryptionPolicy& policy);
-
 }  // namespace vold
 }  // namespace android