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authordrebs <drebs@leap.se>2016-05-07 17:09:29 -0300
committerKali Kaneko <kali@leap.se>2016-06-06 20:07:39 -0400
commit7b468680cc2ad09cf836da0095330d941a5ea7b9 (patch)
tree63308ef8aedbe9fc5aa32165315c7238cf626394
parent86b74a3404c3dc98b422d348edc65848b381f5f1 (diff)
[feat] add recovery doc format version
-rw-r--r--client/changes/next-changelog.rst1
-rw-r--r--client/src/leap/soledad/client/secrets.py91
2 files changed, 79 insertions, 13 deletions
diff --git a/client/changes/next-changelog.rst b/client/changes/next-changelog.rst
index cffe4954..7ddb3a57 100644
--- a/client/changes/next-changelog.rst
+++ b/client/changes/next-changelog.rst
@@ -10,6 +10,7 @@ I've added a new category `Misc` so we can track doc/style/packaging stuff.
Features
~~~~~~~~
+- Add recovery document format version for future migrations.
- Use DeferredLock instead of its locking cousin.
- `#1234 <https://leap.se/code/issues/1234>`_: Description of the new feature corresponding with issue #1234.
- New feature without related issue number.
diff --git a/client/src/leap/soledad/client/secrets.py b/client/src/leap/soledad/client/secrets.py
index 714b2dfe..c35b881e 100644
--- a/client/src/leap/soledad/client/secrets.py
+++ b/client/src/leap/soledad/client/secrets.py
@@ -143,6 +143,8 @@ class SoledadSecrets(object):
KDF_LENGTH_KEY = 'kdf_length'
KDF_SCRYPT = 'scrypt'
CIPHER_AES256 = 'aes256'
+ RECOVERY_DOC_VERSION_KEY = 'version'
+ RECOVERY_DOC_VERSION = 1
"""
Keys used to access storage secrets in recovery documents.
"""
@@ -192,9 +194,15 @@ class SoledadSecrets(object):
# STAGE 1 - verify if secrets exist locally
try:
logger.info("Trying to load secrets from local storage...")
- self._load_secrets_from_local_file()
+ version = self._load_secrets_from_local_file()
+ # eventually migrate local and remote stored documents from old
+ # format version
+ if version < self.RECOVERY_DOC_VERSION:
+ self._store_secrets()
+ self._upload_crypto_secrets()
logger.info("Found secrets in local storage.")
return
+
except NoStorageSecret:
logger.info("Could not find secrets in local storage.")
@@ -204,7 +212,12 @@ class SoledadSecrets(object):
# server.
try:
logger.info('Trying to fetch secrets from remote storage...')
- self._download_crypto_secrets()
+ version = self._download_crypto_secrets()
+ self._store_secrets()
+ # eventually migrate remote stored document from old format
+ # version
+ if version < self.RECOVERY_DOC_VERSION:
+ self._upload_crypto_secrets()
logger.info('Found secrets in remote storage.')
return
except NoStorageSecret:
@@ -240,6 +253,9 @@ class SoledadSecrets(object):
def _load_secrets_from_local_file(self):
"""
Load storage secrets from local file.
+
+ :return version: The version of the locally stored recovery document.
+
:raise NoStorageSecret: Raised if there are no secrets available in
local storage.
"""
@@ -251,13 +267,18 @@ class SoledadSecrets(object):
content = None
with open(self._secrets_path, 'r') as f:
content = json.loads(f.read())
- _, active_secret = self._import_recovery_document(content)
+ _, active_secret, version = self._import_recovery_document(content)
+
self._maybe_set_active_secret(active_secret)
+ return version
+
def _download_crypto_secrets(self):
"""
Download crypto secrets.
+ :return version: The version of the remotelly stored recovery document.
+
:raise NoStorageSecret: Raised if there are no secrets available in
remote storage.
"""
@@ -268,9 +289,10 @@ class SoledadSecrets(object):
if doc is None:
raise NoStorageSecret
- _, active_secret = self._import_recovery_document(doc.content)
+ _, active_secret, version = self._import_recovery_document(doc.content)
self._maybe_set_active_secret(active_secret)
- self._store_secrets() # save new secrets in local file
+
+ return version
def _gen_crypto_secrets(self):
"""
@@ -325,7 +347,7 @@ class SoledadSecrets(object):
"""
Export the storage secrets.
- A recovery document has the following structure:
+ Current format of recovery document has the following structure:
{
'storage_secrets': {
@@ -336,6 +358,7 @@ class SoledadSecrets(object):
},
},
'active_secret': '<secret_id>',
+ 'version': '<recovery document format version>',
}
Note that multiple storage secrets might be stored in one recovery
@@ -353,13 +376,14 @@ class SoledadSecrets(object):
data = {
self.STORAGE_SECRETS_KEY: encrypted_secrets,
self.ACTIVE_SECRET_KEY: self._secret_id,
+ self.RECOVERY_DOC_VERSION_KEY: self.RECOVERY_DOC_VERSION,
}
return data
def _import_recovery_document(self, data):
"""
- Import storage secrets for symmetric encryption and uuid (if present)
- from a recovery document.
+ Import storage secrets for symmetric encryption from a recovery
+ document.
Note that this method does not store the imported data on disk. For
that, use C{self._store_secrets()}.
@@ -367,11 +391,44 @@ class SoledadSecrets(object):
:param data: The recovery document.
:type data: dict
- :return: A tuple containing the number of imported secrets and the
- secret_id of the last active secret.
- :rtype: (int, str)
+ :return: A tuple containing the number of imported secrets, the
+ secret_id of the last active secret, and the recovery
+ document format version.
+ :rtype: (int, str, int)
"""
soledad_assert(self.STORAGE_SECRETS_KEY in data)
+ version = data.get(self.RECOVERY_DOC_VERSION_KEY, 1)
+ meth = getattr(self, '_import_recovery_document_version_%d' % version)
+ secret_count, active_secret = meth(data)
+ return secret_count, active_secret, version
+
+ def _import_recovery_document_version_1(self, data):
+ """
+ Import storage secrets for symmetric encryption from a recovery
+ document with format version 1.
+
+ Version 1 of recovery document has the following structure:
+
+ {
+ 'storage_secrets': {
+ '<storage_secret id>': {
+ 'cipher': 'aes256',
+ 'length': <secret length>,
+ 'secret': '<encrypted storage_secret>',
+ },
+ },
+ 'active_secret': '<secret_id>',
+ 'version': '<recovery document format version>',
+ }
+
+ :param data: The recovery document.
+ :type data: dict
+
+ :return: A tuple containing the number of imported secrets, the
+ secret_id of the last active secret, and the recovery
+ document format version.
+ :rtype: (int, str, int)
+ """
# include secrets in the secret pool.
secret_count = 0
secrets = data[self.STORAGE_SECRETS_KEY].items()
@@ -384,7 +441,7 @@ class SoledadSecrets(object):
if secret_id not in self._secrets:
try:
self._secrets[secret_id] = \
- self._decrypt_storage_secret(encrypted_secret)
+ self._decrypt_storage_secret_version_1(encrypted_secret)
secret_count += 1
except SecretsException as e:
logger.error("Failed to decrypt storage secret: %s"
@@ -443,13 +500,21 @@ class SoledadSecrets(object):
# Management of secret for symmetric encryption.
#
- def _decrypt_storage_secret(self, encrypted_secret_dict):
+ def _decrypt_storage_secret_version_1(self, encrypted_secret_dict):
"""
Decrypt the storage secret.
Storage secret is encrypted before being stored. This method decrypts
and returns the decrypted storage secret.
+ Version 1 of storage secret format has the following structure:
+
+ '<storage_secret id>': {
+ 'cipher': 'aes256',
+ 'length': <secret length>,
+ 'secret': '<encrypted storage_secret>',
+ },
+
:param encrypted_secret_dict: The encrypted storage secret.
:type encrypted_secret_dict: dict