diff options
Diffstat (limited to 'src/lib')
| -rwxr-xr-x | src/lib/Bcfg2/Encryption.py | 149 | ||||
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedCheetahGenerator.py | 6 | ||||
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenerator.py | 31 | ||||
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenshiGenerator.py | 26 | ||||
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Properties.py | 61 |
5 files changed, 198 insertions, 75 deletions
diff --git a/src/lib/Bcfg2/Encryption.py b/src/lib/Bcfg2/Encryption.py index 5e70a1d10..5eb7ffe8e 100755 --- a/src/lib/Bcfg2/Encryption.py +++ b/src/lib/Bcfg2/Encryption.py @@ -1,18 +1,37 @@ -#!/usr/bin/python -Ott +""" Bcfg2.Encryption provides a number of convenience methods for +handling encryption in Bcfg2. See :ref:`server-encryption` for more +details. """ import os -import base64 from M2Crypto import Rand from M2Crypto.EVP import Cipher, EVPError -from Bcfg2.Compat import StringIO, md5 +from Bcfg2.Compat import StringIO, md5, b64encode, b64decode +#: Constant representing the encryption operation for +#: :class:`M2Crypto.EVP.Cipher`, which uses a simple integer. This +#: makes our code more readable. ENCRYPT = 1 + +#: Constant representing the decryption operation for +#: :class:`M2Crypto.EVP.Cipher`, which uses a simple integer. This +#: makes our code more readable. DECRYPT = 0 + +#: Default cipher algorithm. To get a full list of valid algorithms, +#: you can run:: +#: +#: openssl list-cipher-algorithms | grep -v ' => ' | \ +#: tr 'A-Z-' 'a-z_' | sort -u ALGORITHM = "aes_256_cbc" + +#: Default initialization vector. For best security, you should use a +#: unique IV for each message. :func:`ssl_encrypt` does this in an +#: automated fashion. IV = '\0' * 16 Rand.rand_seed(os.urandom(1024)) + def _cipher_filter(cipher, instr): inbuf = StringIO(instr) outbuf = StringIO() @@ -27,54 +46,127 @@ def _cipher_filter(cipher, instr): outbuf.close() return rv + def str_encrypt(plaintext, key, iv=IV, algorithm=ALGORITHM, salt=None): - """ encrypt a string """ + """ Encrypt a string with a key. For a higher-level encryption + interface, see :func:`ssl_encrypt`. + + :param plaintext: The plaintext data to encrypt + :type plaintext: string + :param key: The key to encrypt the data with + :type key: string + :param iv: The initialization vector + :type iv: string + :param algorithm: The cipher algorithm to use + :type algorithm: string + :param salt: The salt to use + :type salt: string + :returns: string - The decrypted data + """ cipher = Cipher(alg=algorithm, key=key, iv=iv, op=ENCRYPT, salt=salt) return _cipher_filter(cipher, plaintext) - + + def str_decrypt(crypted, key, iv=IV, algorithm=ALGORITHM): - """ decrypt a string """ + """ Decrypt a string with a key. For a higher-level decryption + interface, see :func:`ssl_decrypt`. + + :param crypted: The raw binary encrypted data + :type crypted: string + :param key: The encryption key to decrypt with + :type key: string + :param iv: The initialization vector + :type iv: string + :param algorithm: The cipher algorithm to use + :type algorithm: string + :returns: string - The decrypted data + """ cipher = Cipher(alg=algorithm, key=key, iv=iv, op=DECRYPT) return _cipher_filter(cipher, crypted) - + + def ssl_decrypt(data, passwd, algorithm=ALGORITHM): - """ decrypt openssl-encrypted data """ + """ Decrypt openssl-encrypted data. This can decrypt data + encrypted by :func:`ssl_encrypt`, or ``openssl enc``. It performs + a base64 decode first if the data is base64 encoded, and + automatically determines the salt and initialization vector (both + of which are embedded in the encrypted data). + + :param data: The encrypted data (either base64-encoded or raw + binary) to decrypt + :type data: string + :param passwd: The password to use to decrypt the data + :type passwd: string + :param algorithm: The cipher algorithm to use + :type algorithm: string + :returns: string - The decrypted data + """ # base64-decode the data if necessary try: - data = base64.b64decode(data) + data = b64decode(data) except TypeError: # already decoded pass - + salt = data[8:16] hashes = [md5(passwd + salt).digest()] - for i in range(1,3): - hashes.append(md5(hashes[i-1] + passwd + salt).digest()) + for i in range(1, 3): + hashes.append(md5(hashes[i - 1] + passwd + salt).digest()) key = hashes[0] + hashes[1] iv = hashes[2] - - return str_decrypt(data[16:], key=key, iv=iv) + + return str_decrypt(data[16:], key=key, iv=iv, algorithm=algorithm) + def ssl_encrypt(plaintext, passwd, algorithm=ALGORITHM, salt=None): - """ encrypt data in a format that is openssl compatible """ + """ Encrypt data in a format that is openssl compatible. + + :param plaintext: The plaintext data to encrypt + :type plaintext: string + :param passwd: The password to use to encrypt the data + :type passwd: string + :param algorithm: The cipher algorithm to use + :type algorithm: string + :param salt: The salt to use. If none is provided, one will be + randomly generated. + :type salt: bytes + :returns: string - The base64-encoded, salted, encrypted string. + The string includes a trailing newline to make it fully + compatible with openssl command-line tools. + """ if salt is None: salt = Rand.rand_bytes(8) - + hashes = [md5(passwd + salt).digest()] - for i in range(1,3): - hashes.append(md5(hashes[i-1] + passwd + salt).digest()) + for i in range(1, 3): + hashes.append(md5(hashes[i - 1] + passwd + salt).digest()) key = hashes[0] + hashes[1] iv = hashes[2] - - crypted = str_encrypt(plaintext, key=key, salt=salt, iv=iv) - return base64.b64encode("Salted__" + salt + crypted) + "\n" + + crypted = str_encrypt(plaintext, key=key, salt=salt, iv=iv, + algorithm=algorithm) + return b64encode("Salted__" + salt + crypted) + "\n" + + +def get_algorithm(setup): + """ Get the cipher algorithm from the config file. This is used + in case someone uses the OpenSSL algorithm name (e.g., + "AES-256-CBC") instead of the M2Crypto name (e.g., "aes_256_cbc"), + and to handle errors in a sensible way and deduplicate this code. + + :param setup: The Bcfg2 option set to extract passphrases from + :type setup: Bcfg2.Options.OptionParser + :returns: dict - a dict of ``<passphrase name>``: ``<passphrase>`` + """ + return setup.cfp.get("encryption", "algorithm", + default=ALGORITHM).lower().replace("-", "_") def get_passphrases(setup): """ Get all candidate encryption passphrases from the config file. :param setup: The Bcfg2 option set to extract passphrases from :type setup: Bcfg2.Options.OptionParser - returns: dict - a dict of <passphrase name>: <passphrase> + :returns: dict - a dict of ``<passphrase name>``: ``<passphrase>`` """ section = "encryption" if setup.cfp.has_section(section): @@ -83,11 +175,13 @@ def get_passphrases(setup): else: return dict() -def bruteforce_decrypt(crypted, passphrases=None, setup=None): + +def bruteforce_decrypt(crypted, passphrases=None, setup=None, + algorithm=ALGORITHM): """ Convenience method to decrypt the given encrypted string by trying the given passphrases or all passphrases (as returned by - :func:`Bcfg2.Encryption.passphrases`) sequentially until one is - found that works. + :func:`get_passphrases`) sequentially until one is found that + works. Either ``passphrases`` or ``setup`` must be provided. @@ -97,6 +191,8 @@ def bruteforce_decrypt(crypted, passphrases=None, setup=None): :type passphrases: list :param setup: A Bcfg2 option set to extract passphrases from :type setup: Bcfg2.Options.OptionParser + :param algorithm: The cipher algorithm to use + :type algorithm: string :returns: string - The decrypted data :raises: :class:`M2Crypto.EVP.EVPError`, if the data cannot be decrypted """ @@ -104,8 +200,7 @@ def bruteforce_decrypt(crypted, passphrases=None, setup=None): passphrases = get_passphrases(setup).values() for passwd in passphrases: try: - return ssl_decrypt(crypted, passwd) + return ssl_decrypt(crypted, passwd, algorithm=algorithm) except EVPError: pass raise EVPError("Failed to decrypt") - diff --git a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedCheetahGenerator.py b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedCheetahGenerator.py index 3e714c01f..9eed633c4 100644 --- a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedCheetahGenerator.py +++ b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedCheetahGenerator.py @@ -2,12 +2,14 @@ .cheetah.crypt files)""" from Bcfg2.Server.Plugins.Cfg.CfgCheetahGenerator import CfgCheetahGenerator -from Bcfg2.Server.Plugins.Cfg.CfgEncryptedGenerator import CfgEncryptedGenerator +from Bcfg2.Server.Plugins.Cfg.CfgEncryptedGenerator \ + import CfgEncryptedGenerator + class CfgEncryptedCheetahGenerator(CfgCheetahGenerator, CfgEncryptedGenerator): """ CfgEncryptedCheetahGenerator lets you encrypt your Cheetah :ref:`server-plugins-generators-cfg` files on the server """ - + #: handle .crypt.cheetah or .cheetah.crypt files __extensions__ = ['cheetah.crypt', 'crypt.cheetah'] diff --git a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenerator.py b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenerator.py index 71e407d17..f8d08b394 100644 --- a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenerator.py +++ b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenerator.py @@ -2,15 +2,17 @@ :ref:`server-plugins-generators-cfg` files on the server. """ import logging -import Bcfg2.Server.Plugin +from Bcfg2.Server.Plugin import PluginExecutionError from Bcfg2.Server.Plugins.Cfg import CfgGenerator, SETUP try: - from Bcfg2.Encryption import bruteforce_decrypt, EVPError - have_crypto = True + from Bcfg2.Encryption import bruteforce_decrypt, EVPError, \ + get_algorithm + HAS_CRYPTO = True except ImportError: - have_crypto = False + HAS_CRYPTO = False + +LOGGER = logging.getLogger(__name__) -logger = logging.getLogger(__name__) class CfgEncryptedGenerator(CfgGenerator): """ CfgEncryptedGenerator lets you encrypt your plaintext @@ -21,10 +23,10 @@ class CfgEncryptedGenerator(CfgGenerator): def __init__(self, fname, spec, encoding): CfgGenerator.__init__(self, fname, spec, encoding) - if not have_crypto: - msg = "Cfg: M2Crypto is not available: %s" % entry.get("name") - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + if not HAS_CRYPTO: + msg = "Cfg: M2Crypto is not available" + LOGGER.error(msg) + raise PluginExecutionError(msg) __init__.__doc__ = CfgGenerator.__init__.__doc__ def handle_event(self, event): @@ -35,19 +37,20 @@ class CfgEncryptedGenerator(CfgGenerator): except UnicodeDecodeError: crypted = open(self.name, mode='rb').read() except: - logger.error("Failed to read %s" % self.name) + LOGGER.error("Failed to read %s" % self.name) return # todo: let the user specify a passphrase by name try: - self.data = bruteforce_decrypt(crypted, setup=SETUP) + self.data = bruteforce_decrypt(crypted, setup=SETUP, + algorithm=get_algorithm(SETUP)) except EVPError: msg = "Failed to decrypt %s" % self.name - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + LOGGER.error(msg) + raise PluginExecutionError(msg) handle_event.__doc__ = CfgGenerator.handle_event.__doc__ def get_data(self, entry, metadata): if self.data is None: - raise Bcfg2.Server.Plugin.PluginExecutionError("Failed to decrypt %s" % self.name) + raise PluginExecutionError("Failed to decrypt %s" % self.name) return CfgGenerator.get_data(self, entry, metadata) get_data.__doc__ = CfgGenerator.get_data.__doc__ diff --git a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenshiGenerator.py b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenshiGenerator.py index 0d5d98ba6..6fd70e69f 100644 --- a/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenshiGenerator.py +++ b/src/lib/Bcfg2/Server/Plugins/Cfg/CfgEncryptedGenshiGenerator.py @@ -1,15 +1,17 @@ """ Handle encrypted Genshi templates (.crypt.genshi or .genshi.crypt files) """ +import logging from Bcfg2.Compat import StringIO +from Bcfg2.Server.Plugin import PluginExecutionError +from Bcfg2.Server.Plugins.Cfg import SETUP from Bcfg2.Server.Plugins.Cfg.CfgGenshiGenerator import CfgGenshiGenerator -from Bcfg2.Server.Plugins.Cfg.CfgEncryptedGenerator import CfgEncryptedGenerator try: - from Bcfg2.Encryption import bruteforce_decrypt + from Bcfg2.Encryption import bruteforce_decrypt, get_algorithm + HAS_CRYPTO = True except ImportError: - # CfgGenshiGenerator will raise errors if crypto doesn't exist - pass + HAS_CRYPTO = False try: from genshi.template import TemplateLoader @@ -17,21 +19,25 @@ except ImportError: # CfgGenshiGenerator will raise errors if genshi doesn't exist TemplateLoader = object +LOGGER = logging.getLogger(__name__) + class EncryptedTemplateLoader(TemplateLoader): """ Subclass :class:`genshi.template.TemplateLoader` to decrypt the data on the fly as it's read in using :func:`Bcfg2.Encryption.bruteforce_decrypt` """ def _instantiate(self, cls, fileobj, filepath, filename, encoding=None): - plaintext = StringIO(bruteforce_decrypt(fileobj.read())) + plaintext = \ + StringIO(bruteforce_decrypt(fileobj.read(), + algorithm=get_algorithm(SETUP))) return TemplateLoader._instantiate(self, cls, plaintext, filepath, filename, encoding=encoding) - + class CfgEncryptedGenshiGenerator(CfgGenshiGenerator): """ CfgEncryptedGenshiGenerator lets you encrypt your Genshi :ref:`server-plugins-generators-cfg` files on the server """ - + #: handle .crypt.genshi or .genshi.crypt files __extensions__ = ['genshi.crypt', 'crypt.genshi'] @@ -39,3 +45,9 @@ class CfgEncryptedGenshiGenerator(CfgGenshiGenerator): #: when it's read in __loader_cls__ = EncryptedTemplateLoader + def __init__(self, fname, spec, encoding): + CfgGenshiGenerator.__init__(self, fname, spec, encoding) + if not HAS_CRYPTO: + msg = "Cfg: M2Crypto is not available" + LOGGER.error(msg) + raise PluginExecutionError(msg) diff --git a/src/lib/Bcfg2/Server/Plugins/Properties.py b/src/lib/Bcfg2/Server/Plugins/Properties.py index 1b925ce46..590d536a9 100644 --- a/src/lib/Bcfg2/Server/Plugins/Properties.py +++ b/src/lib/Bcfg2/Server/Plugins/Properties.py @@ -5,46 +5,50 @@ import copy import logging import lxml.etree import Bcfg2.Server.Plugin +from Bcfg2.Server.Plugin import PluginExecutionError try: from Bcfg2.Encryption import ssl_decrypt, get_passphrases, \ - bruteforce_decrypt, EVPError - have_crypto = True + get_algorithm, bruteforce_decrypt, EVPError + HAS_CRYPTO = True except ImportError: - have_crypto = False + HAS_CRYPTO = False -logger = logging.getLogger(__name__) +LOGGER = logging.getLogger(__name__) SETUP = None class PropertyFile(Bcfg2.Server.Plugin.StructFile): - """Class for properties files.""" + """ Class for properties files. """ + def write(self): """ Write the data in this data structure back to the property file """ if not SETUP.cfp.getboolean("properties", "writes_enabled", default=True): - msg = "Properties files write-back is disabled in the configuration" - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + msg = "Properties files write-back is disabled in the " + \ + "configuration" + LOGGER.error(msg) + raise PluginExecutionError(msg) try: self.validate_data() - except Bcfg2.Server.Plugin.PluginExecutionError: + except PluginExecutionError: msg = "Cannot write %s: %s" % (self.name, sys.exc_info()[1]) - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + LOGGER.error(msg) + raise PluginExecutionError(msg) try: open(self.name, - "wb").write(lxml.etree.tostring(self.xdata, - xml_declaration=False, - pretty_print=True).decode('UTF-8')) + "wb").write( + lxml.etree.tostring(self.xdata, + xml_declaration=False, + pretty_print=True).decode('UTF-8')) return True except IOError: err = sys.exc_info()[1] msg = "Failed to write %s: %s" % (self.name, err) - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + LOGGER.error(msg) + raise PluginExecutionError(msg) def validate_data(self): """ ensure that the data in this object validates against the @@ -55,31 +59,34 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile): schema = lxml.etree.XMLSchema(file=schemafile) except: err = sys.exc_info()[1] - raise Bcfg2.Server.Plugin.PluginExecutionError("Failed to process schema for %s: %s" % (self.name, err)) + raise PluginExecutionError("Failed to process schema for %s: " + "%s" % (self.name, err)) else: # no schema exists return True if not schema.validate(self.xdata): - raise Bcfg2.Server.Plugin.PluginExecutionError("Data for %s fails to validate; run bcfg2-lint for more details" % self.name) + raise PluginExecutionError("Data for %s fails to validate; run " + "bcfg2-lint for more details" % + self.name) else: return True def Index(self): Bcfg2.Server.Plugin.StructFile.Index(self) if self.xdata.get("encryption", "false").lower() != "false": - if not have_crypto: + if not HAS_CRYPTO: msg = "Properties: M2Crypto is not available: %s" % self.name - logger.error(msg) - raise Bcfg2.Server.Plugin.PluginExecutionError(msg) + LOGGER.error(msg) + raise PluginExecutionError(msg) for el in self.xdata.xpath("//*[@encrypted]"): try: el.text = self._decrypt(el) except EVPError: msg = "Failed to decrypt %s element in %s" % (el.tag, self.name) - logger.error(msg) - raise Bcfg2.Server.PluginExecutionError(msg) + LOGGER.error(msg) + raise PluginExecutionError(msg) def _decrypt(self, element): if not element.text.strip(): @@ -88,14 +95,18 @@ class PropertyFile(Bcfg2.Server.Plugin.StructFile): try: passphrase = passes[element.get("encrypted")] try: - return ssl_decrypt(element.text, passphrase) + return ssl_decrypt(element.text, passphrase, + algorithm=get_algorithm(SETUP)) except EVPError: # error is raised below pass except KeyError: - return bruteforce_decrypt(element.text, passphrases=passes.values()) + return bruteforce_decrypt(element.text, + passphrases=passes.values(), + algorithm=get_algorithm(SETUP)) raise EVPError("Failed to decrypt") + class PropDirectoryBacked(Bcfg2.Server.Plugin.DirectoryBacked): __child__ = PropertyFile patterns = re.compile(r'.*\.xml$') |