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heat/heat/engine/resources/openstack/heat/random_string.py

291 lines
11 KiB

#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import random
import string
import six
from heat.common import exception
from heat.common.i18n import _
from heat.engine import attributes
from heat.engine import constraints
from heat.engine import properties
from heat.engine import resource
from heat.engine import support
class RandomString(resource.Resource):
'''
A resource which generates a random string.
This is useful for configuring passwords and secrets on services.
'''
support_status = support.SupportStatus(version='2014.1')
PROPERTIES = (
LENGTH, SEQUENCE, CHARACTER_CLASSES, CHARACTER_SEQUENCES,
SALT,
) = (
'length', 'sequence', 'character_classes', 'character_sequences',
'salt',
)
_CHARACTER_CLASSES_KEYS = (
CHARACTER_CLASSES_CLASS, CHARACTER_CLASSES_MIN,
) = (
'class', 'min',
)
_CHARACTER_SEQUENCES = (
CHARACTER_SEQUENCES_SEQUENCE, CHARACTER_SEQUENCES_MIN,
) = (
'sequence', 'min',
)
ATTRIBUTES = (
VALUE,
) = (
'value',
)
properties_schema = {
LENGTH: properties.Schema(
properties.Schema.INTEGER,
_('Length of the string to generate.'),
default=32,
constraints=[
constraints.Range(1, 512),
]
),
SEQUENCE: properties.Schema(
properties.Schema.STRING,
_('Sequence of characters to build the random string from.'),
constraints=[
constraints.AllowedValues(['lettersdigits', 'letters',
'lowercase', 'uppercase',
'digits', 'hexdigits',
'octdigits']),
],
support_status=support.SupportStatus(
status=support.DEPRECATED,
message=_('Use property %s.') % CHARACTER_CLASSES,
version='2014.2'
)
),
CHARACTER_CLASSES: properties.Schema(
properties.Schema.LIST,
_('A list of character class and their constraints to generate '
'the random string from.'),
schema=properties.Schema(
properties.Schema.MAP,
schema={
CHARACTER_CLASSES_CLASS: properties.Schema(
properties.Schema.STRING,
(_('A character class and its corresponding %(min)s '
'constraint to generate the random string from.')
% {'min': CHARACTER_CLASSES_MIN}),
constraints=[
constraints.AllowedValues(
['lettersdigits', 'letters', 'lowercase',
'uppercase', 'digits', 'hexdigits',
'octdigits']),
],
default='lettersdigits'),
CHARACTER_CLASSES_MIN: properties.Schema(
properties.Schema.INTEGER,
_('The minimum number of characters from this '
'character class that will be in the generated '
'string.'),
default=1,
constraints=[
constraints.Range(1, 512),
]
)
}
)
),
CHARACTER_SEQUENCES: properties.Schema(
properties.Schema.LIST,
_('A list of character sequences and their constraints to '
'generate the random string from.'),
schema=properties.Schema(
properties.Schema.MAP,
schema={
CHARACTER_SEQUENCES_SEQUENCE: properties.Schema(
properties.Schema.STRING,
_('A character sequence and its corresponding %(min)s '
'constraint to generate the random string '
'from.') % {'min': CHARACTER_SEQUENCES_MIN},
required=True),
CHARACTER_SEQUENCES_MIN: properties.Schema(
properties.Schema.INTEGER,
_('The minimum number of characters from this '
'sequence that will be in the generated '
'string.'),
default=1,
constraints=[
constraints.Range(1, 512),
]
)
}
)
),
SALT: properties.Schema(
properties.Schema.STRING,
_('Value which can be set or changed on stack update to trigger '
'the resource for replacement with a new random string . The '
'salt value itself is ignored by the random generator.')
),
}
attributes_schema = {
VALUE: attributes.Schema(
_('The random string generated by this resource. This value is '
'also available by referencing the resource.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}
_sequences = {
'lettersdigits': string.ascii_letters + string.digits,
'letters': string.ascii_letters,
'lowercase': string.ascii_lowercase,
'uppercase': string.ascii_uppercase,
'digits': string.digits,
'hexdigits': string.digits + 'ABCDEF',
'octdigits': string.octdigits
}
@staticmethod
def _deprecated_random_string(sequence, length):
rand = random.SystemRandom()
return ''.join(rand.choice(sequence) for x in six.moves.xrange(length))
def _generate_random_string(self, char_sequences, char_classes, length):
random_string = ""
# Add the minimum number of chars from each char sequence & char class
if char_sequences:
for char_seq in char_sequences:
seq = char_seq[self.CHARACTER_SEQUENCES_SEQUENCE]
seq_min = char_seq[self.CHARACTER_SEQUENCES_MIN]
for i in six.moves.xrange(seq_min):
random_string += random.choice(seq)
if char_classes:
for char_class in char_classes:
cclass_class = char_class[self.CHARACTER_CLASSES_CLASS]
cclass_seq = self._sequences[cclass_class]
cclass_min = char_class[self.CHARACTER_CLASSES_MIN]
for i in six.moves.xrange(cclass_min):
random_string += random.choice(cclass_seq)
def random_class_char():
cclass_dict = random.choice(char_classes)
cclass_class = cclass_dict[self.CHARACTER_CLASSES_CLASS]
cclass_seq = self._sequences[cclass_class]
return random.choice(cclass_seq)
def random_seq_char():
seq_dict = random.choice(char_sequences)
seq = seq_dict[self.CHARACTER_SEQUENCES_SEQUENCE]
return random.choice(seq)
# Fill up rest with random chars from provided sequences & classes
if char_sequences and char_classes:
weighted_choices = ([True] * len(char_classes) +
[False] * len(char_sequences))
while len(random_string) < length:
if random.choice(weighted_choices):
random_string += random_class_char()
else:
random_string += random_seq_char()
elif char_sequences:
while len(random_string) < length:
random_string += random_seq_char()
else:
while len(random_string) < length:
random_string += random_class_char()
# Randomize string
random_string = ''.join(random.sample(random_string,
len(random_string)))
return random_string
def validate(self):
super(RandomString, self).validate()
sequence = self.properties[self.SEQUENCE]
char_sequences = self.properties[self.CHARACTER_SEQUENCES]
char_classes = self.properties[self.CHARACTER_CLASSES]
if sequence and (char_sequences or char_classes):
msg = (_("Cannot use deprecated '%(seq)s' property along with "
"'%(char_seqs)s' or '%(char_classes)s' properties")
% {'seq': self.SEQUENCE,
'char_seqs': self.CHARACTER_SEQUENCES,
'char_classes': self.CHARACTER_CLASSES})
raise exception.StackValidationFailed(message=msg)
def char_min(char_dicts, min_prop):
if char_dicts:
return sum(char_dict[min_prop] for char_dict in char_dicts)
return 0
length = self.properties[self.LENGTH]
min_length = (char_min(char_sequences, self.CHARACTER_SEQUENCES_MIN) +
char_min(char_classes, self.CHARACTER_CLASSES_MIN))
if min_length > length:
msg = _("Length property cannot be smaller than combined "
"character class and character sequence minimums")
raise exception.StackValidationFailed(message=msg)
def handle_create(self):
char_sequences = self.properties[self.CHARACTER_SEQUENCES]
char_classes = self.properties[self.CHARACTER_CLASSES]
length = self.properties[self.LENGTH]
if char_sequences or char_classes:
random_string = self._generate_random_string(char_sequences,
char_classes,
length)
else:
sequence = self.properties[self.SEQUENCE]
if not sequence: # Deprecated property not provided, use a default
sequence = "lettersdigits"
char_seq = self._sequences[sequence]
random_string = self._deprecated_random_string(char_seq, length)
self.data_set('value', random_string, redact=True)
self.resource_id_set(self.physical_resource_name())
def _resolve_attribute(self, name):
if name == self.VALUE:
return self.data().get(self.VALUE)
def FnGetRefId(self):
if self.resource_id is not None:
return self.data().get('value')
else:
return six.text_type(self.name)
def resource_mapping():
return {
'OS::Heat::RandomString': RandomString,
}