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Refactor MetadataCrypt.cpp to make create_crypto_blk_dev more general

Browse source 
Bug: 147814592
Test: Treehugger
Change-Id: I13c6f84d729f2953f78626493d6e6d34d578a013
This commit is contained in:
Paul Crowley 2020-02-14 01:15:35 -08:00
parent 220567c33a
commit 572c024853
1 changed files with 50 additions and 47 deletions
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97
MetadataCrypt.cpp
View file

@ -146,12 +146,11 @@ static bool retrieveMetadataKey(bool create_if_absent, const std::string& key_pa
return true;
}
static bool read_key(const FstabEntry& data_rec, bool create_if_absent, KeyBuffer* key) {
if (data_rec.metadata_key_dir.empty()) {
static bool read_key(const std::string& metadata_key_dir, bool create_if_absent, KeyBuffer* key) {
if (metadata_key_dir.empty()) {
LOG(ERROR) << "Failed to get metadata_key_dir";
return false;
}
std::string metadata_key_dir = data_rec.metadata_key_dir;
std::string sKey;
auto dir = metadata_key_dir + "/key";
LOG(DEBUG) << "metadata_key_dir/key: " << dir;
@ -189,41 +188,11 @@ static bool get_number_of_sectors(const std::string& real_blkdev, uint64_t* nr_s
return true;
}
static const CryptoType& lookup_cipher_in_table(const CryptoType table[], int table_len,
const std::string& cipher_name) {
if (cipher_name.empty()) return table[0];
for (int i = 0; i < table_len; i++) {
if (cipher_name == table[i].get_config_name()) {
return table[i];
}
}
return invalid_crypto_type;
}
static const CryptoType& lookup_cipher(const std::string& cipher_name, bool is_legacy) {
if (is_legacy) {
return lookup_cipher_in_table(legacy_crypto_types, array_length(legacy_crypto_types),
cipher_name);
} else {
return lookup_cipher_in_table(supported_crypto_types, array_length(supported_crypto_types),
cipher_name);
}
}
static bool create_crypto_blk_dev(const std::string& dm_name, const FstabEntry* data_rec,
static bool create_crypto_blk_dev(const std::string& dm_name, const std::string& blk_device,
bool is_legacy, const std::string& cipher, bool set_dun,
const KeyBuffer& key, std::string* crypto_blkdev) {
uint64_t nr_sec;
if (!get_number_of_sectors(data_rec->blk_device, &nr_sec)) return false;
bool is_legacy;
if (!DmTargetDefaultKey::IsLegacy(&is_legacy)) return false;
auto cipher = lookup_cipher(data_rec->metadata_cipher, is_legacy);
if (cipher.get_kernel_name() == nullptr) {
LOG(ERROR) << "No metadata cipher named " << data_rec->metadata_cipher
<< " found, is_legacy=" << is_legacy;
return false;
}
if (!get_number_of_sectors(blk_device, &nr_sec)) return false;
KeyBuffer hex_key_buffer;
if (android::vold::StrToHex(key, hex_key_buffer) != android::OK) {
@ -232,16 +201,9 @@ static bool create_crypto_blk_dev(const std::string& dm_name, const FstabEntry*
}
std::string hex_key(hex_key_buffer.data(), hex_key_buffer.size());
// Non-legacy driver always sets DUN
bool set_dun = !is_legacy || android::base::GetBoolProperty("ro.crypto.set_dun", false);
if (!set_dun && data_rec->fs_mgr_flags.checkpoint_blk) {
LOG(ERROR) << "Block checkpoints and metadata encryption require ro.crypto.set_dun option";
return false;
}
DmTable table;
table.Emplace<DmTargetDefaultKey>(0, nr_sec, cipher.get_kernel_name(), hex_key,
data_rec->blk_device, 0, is_legacy, set_dun);
table.Emplace<DmTargetDefaultKey>(0, nr_sec, cipher, hex_key, blk_device, 0, is_legacy,
set_dun);
auto& dm = DeviceMapper::Instance();
for (int i = 0;; i++) {
@ -263,6 +225,27 @@ static bool create_crypto_blk_dev(const std::string& dm_name, const FstabEntry*
return true;
}
static const CryptoType& lookup_cipher_in_table(const CryptoType table[], int table_len,
const std::string& cipher_name) {
if (cipher_name.empty()) return table[0];
for (int i = 0; i < table_len; i++) {
if (cipher_name == table[i].get_config_name()) {
return table[i];
}
}
return invalid_crypto_type;
}
static const CryptoType& lookup_cipher(const std::string& cipher_name, bool is_legacy) {
if (is_legacy) {
return lookup_cipher_in_table(legacy_crypto_types, array_length(legacy_crypto_types),
cipher_name);
} else {
return lookup_cipher_in_table(supported_crypto_types, array_length(supported_crypto_types),
cipher_name);
}
}
bool fscrypt_mount_metadata_encrypted(const std::string& blk_device, const std::string& mount_point,
bool needs_encrypt) {
LOG(DEBUG) << "fscrypt_mount_metadata_encrypted: " << mount_point << " " << needs_encrypt;
@ -282,11 +265,31 @@ bool fscrypt_mount_metadata_encrypted(const std::string& blk_device, const std::
<< data_rec->blk_device << " for " << mount_point;
return false;
}
bool is_legacy;
if (!DmTargetDefaultKey::IsLegacy(&is_legacy)) return false;
// Non-legacy driver always sets DUN
bool set_dun = !is_legacy || android::base::GetBoolProperty("ro.crypto.set_dun", false);
if (!set_dun && data_rec->fs_mgr_flags.checkpoint_blk) {
LOG(ERROR) << "Block checkpoints and metadata encryption require ro.crypto.set_dun option";
return false;
}
auto cipher = lookup_cipher(data_rec->metadata_cipher, is_legacy);
if (cipher.get_kernel_name() == nullptr) {
LOG(ERROR) << "No metadata cipher named " << data_rec->metadata_cipher
<< " found, is_legacy=" << is_legacy;
return false;
}
KeyBuffer key;
if (!read_key(*data_rec, needs_encrypt, &key)) return false;
if (!read_key(data_rec->metadata_key_dir, needs_encrypt, &key)) return false;
std::string crypto_blkdev;
if (!create_crypto_blk_dev(kDmNameUserdata, data_rec, key, &crypto_blkdev)) return false;
if (!create_crypto_blk_dev(kDmNameUserdata, data_rec->blk_device, is_legacy,
cipher.get_kernel_name(), set_dun, key, &crypto_blkdev))
return false;
// FIXME handle the corrupt case
if (needs_encrypt) {