Skip to content
This repository
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 423 lines (360 sloc) 16.16 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422
# Copyright 2010 Google Inc.
# Copyright (c) 2011 Mitch Garnaat http://garnaat.org/
# Copyright (c) 2011, Eucalyptus Systems, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish, dis-
# tribute, sublicense, and/or sell copies of the Software, and to permit
# persons to whom the Software is furnished to do so, subject to the fol-
# lowing conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.


"""
Handles authentication required to AWS and GS
"""

import base64
import boto
import boto.auth_handler
import boto.exception
import boto.plugin
import boto.utils
import hmac
import sys
import urllib
from email.utils import formatdate

from boto.auth_handler import AuthHandler
from boto.exception import BotoClientError
#
# the following is necessary because of the incompatibilities
# between Python 2.4, 2.5, and 2.6 as well as the fact that some
# people running 2.4 have installed hashlib as a separate module
# this fix was provided by boto user mccormix.
# see: http://code.google.com/p/boto/issues/detail?id=172
# for more details.
#
try:
    from hashlib import sha1 as sha
    from hashlib import sha256 as sha256

    if sys.version[:3] == "2.4":
        # we are using an hmac that expects a .new() method.
        class Faker:
            def __init__(self, which):
                self.which = which
                self.digest_size = self.which().digest_size

            def new(self, *args, **kwargs):
                return self.which(*args, **kwargs)

        sha = Faker(sha)
        sha256 = Faker(sha256)

except ImportError:
    import sha
    sha256 = None

class HmacKeys(object):
    """Key based Auth handler helper."""

    def __init__(self, host, config, provider):
        if provider.access_key is None or provider.secret_key is None:
            raise boto.auth_handler.NotReadyToAuthenticate()
        self.host = host
        self.update_provider(provider)

    def update_provider(self, provider):
        self._provider = provider
        self._hmac = hmac.new(self._provider.secret_key, digestmod=sha)
        if sha256:
            self._hmac_256 = hmac.new(self._provider.secret_key,
                                      digestmod=sha256)
        else:
            self._hmac_256 = None

    def algorithm(self):
        if self._hmac_256:
            return 'HmacSHA256'
        else:
            return 'HmacSHA1'

    def sign_string(self, string_to_sign):
        if self._hmac_256:
            hmac = self._hmac_256.copy()
        else:
            hmac = self._hmac.copy()
        hmac.update(string_to_sign)
        return base64.encodestring(hmac.digest()).strip()

class AnonAuthHandler(AuthHandler, HmacKeys):
    """
Implements Anonymous requests.
"""
    
    capability = ['anon']
    
    def __init__(self, host, config, provider):
        AuthHandler.__init__(self, host, config, provider)
        
    def add_auth(self, http_request, **kwargs):
        pass

class HmacAuthV1Handler(AuthHandler, HmacKeys):
    """ Implements the HMAC request signing used by S3 and GS."""
    
    capability = ['hmac-v1', 's3']
    
    def __init__(self, host, config, provider):
        AuthHandler.__init__(self, host, config, provider)
        HmacKeys.__init__(self, host, config, provider)
        self._hmac_256 = None
        
    def add_auth(self, http_request, **kwargs):
        headers = http_request.headers
        method = http_request.method
        auth_path = http_request.auth_path
        if not headers.has_key('Date'):
            headers['Date'] = formatdate(usegmt=True)

        if self._provider.security_token:
            key = self._provider.security_token_header
            headers[key] = self._provider.security_token
        string_to_sign = boto.utils.canonical_string(method, auth_path,
                                                     headers, None,
                                                     self._provider)
        boto.log.debug('StringToSign:\n%s' % string_to_sign)
        b64_hmac = self.sign_string(string_to_sign)
        auth_hdr = self._provider.auth_header
        headers['Authorization'] = ("%s %s:%s" %
                                    (auth_hdr,
                                     self._provider.access_key, b64_hmac))

class HmacAuthV2Handler(AuthHandler, HmacKeys):
    """
Implements the simplified HMAC authorization used by CloudFront.
"""
    capability = ['hmac-v2', 'cloudfront']
    
    def __init__(self, host, config, provider):
        AuthHandler.__init__(self, host, config, provider)
        HmacKeys.__init__(self, host, config, provider)
        self._hmac_256 = None
        
    def add_auth(self, http_request, **kwargs):
        headers = http_request.headers
        if not headers.has_key('Date'):
            headers['Date'] = formatdate(usegmt=True)

        b64_hmac = self.sign_string(headers['Date'])
        auth_hdr = self._provider.auth_header
        headers['Authorization'] = ("%s %s:%s" %
                                    (auth_hdr,
                                     self._provider.access_key, b64_hmac))
        
class HmacAuthV3Handler(AuthHandler, HmacKeys):
    """Implements the new Version 3 HMAC authorization used by Route53."""
    
    capability = ['hmac-v3', 'route53', 'ses']
    
    def __init__(self, host, config, provider):
        AuthHandler.__init__(self, host, config, provider)
        HmacKeys.__init__(self, host, config, provider)
        
    def add_auth(self, http_request, **kwargs):
        headers = http_request.headers
        if not headers.has_key('Date'):
            headers['Date'] = formatdate(usegmt=True)

        b64_hmac = self.sign_string(headers['Date'])
        s = "AWS3-HTTPS AWSAccessKeyId=%s," % self._provider.access_key
        s += "Algorithm=%s,Signature=%s" % (self.algorithm(), b64_hmac)
        headers['X-Amzn-Authorization'] = s

class HmacAuthV3HTTPHandler(AuthHandler, HmacKeys):
    """
Implements the new Version 3 HMAC authorization used by DynamoDB.
"""
    
    capability = ['hmac-v3-http']
    
    def __init__(self, host, config, provider):
        AuthHandler.__init__(self, host, config, provider)
        HmacKeys.__init__(self, host, config, provider)

    def headers_to_sign(self, http_request):
        """
Select the headers from the request that need to be included
in the StringToSign.
"""
        headers_to_sign = {}
        headers_to_sign = {'Host' : self.host}
        for name, value in http_request.headers.items():
            lname = name.lower()
            if lname.startswith('x-amz'):
                headers_to_sign[name] = value
        return headers_to_sign

    def canonical_headers(self, headers_to_sign):
        """
Return the headers that need to be included in the StringToSign
in their canonical form by converting all header keys to lower
case, sorting them in alphabetical order and then joining
them into a string, separated by newlines.
"""
        l = ['%s:%s'%(n.lower().strip(),
                      headers_to_sign[n].strip()) for n in headers_to_sign]
        l.sort()
        return '\n'.join(l)
        
    def string_to_sign(self, http_request):
        """
Return the canonical StringToSign as well as a dict
containing the original version of all headers that
were included in the StringToSign.
"""
        headers_to_sign = self.headers_to_sign(http_request)
        canonical_headers = self.canonical_headers(headers_to_sign)
        string_to_sign = '\n'.join([http_request.method,
                                    http_request.path,
                                    '',
                                    canonical_headers,
                                    '',
                                    http_request.body])
        return string_to_sign, headers_to_sign
        
    def add_auth(self, req, **kwargs):
        """
Add AWS3 authentication to a request.

:type req: :class`boto.connection.HTTPRequest`
:param req: The HTTPRequest object.
"""
        # This could be a retry. Make sure the previous
        # authorization header is removed first.
        if 'X-Amzn-Authorization' in req.headers:
            del req.headers['X-Amzn-Authorization']
        req.headers['X-Amz-Date'] = formatdate(usegmt=True)
        req.headers['X-Amz-Security-Token'] = self._provider.security_token
        string_to_sign, headers_to_sign = self.string_to_sign(req)
        boto.log.debug('StringToSign:\n%s' % string_to_sign)
        hash_value = sha256(string_to_sign).digest()
        b64_hmac = self.sign_string(hash_value)
        s = "AWS3 AWSAccessKeyId=%s," % self._provider.access_key
        s += "Algorithm=%s," % self.algorithm()
        s += "SignedHeaders=%s," % ';'.join(headers_to_sign)
        s += "Signature=%s" % b64_hmac
        req.headers['X-Amzn-Authorization'] = s

class QuerySignatureHelper(HmacKeys):
    """
Helper for Query signature based Auth handler.

Concrete sub class need to implement _calc_sigature method.
"""

    def add_auth(self, http_request, **kwargs):
        headers = http_request.headers
        params = http_request.params
        params['AWSAccessKeyId'] = self._provider.access_key
        params['SignatureVersion'] = self.SignatureVersion
        params['Timestamp'] = boto.utils.get_ts()
        qs, signature = self._calc_signature(
            http_request.params, http_request.method,
            http_request.auth_path, http_request.host)
        boto.log.debug('query_string: %s Signature: %s' % (qs, signature))
        if http_request.method == 'POST':
            headers['Content-Type'] = 'application/x-www-form-urlencoded; charset=UTF-8'
            http_request.body = qs + '&Signature=' + urllib.quote(signature)
            http_request.headers['Content-Length'] = str(len(http_request.body))
        else:
            http_request.body = ''
            # if this is a retried request, the qs from the previous try will
            # already be there, we need to get rid of that and rebuild it
            http_request.path = http_request.path.split('?')[0]
            http_request.path = (http_request.path + '?' + qs +
                                 '&Signature=' + urllib.quote(signature))

class QuerySignatureV0AuthHandler(QuerySignatureHelper, AuthHandler):
    """Provides Signature V0 Signing"""

    SignatureVersion = 0
    capability = ['sign-v0']

    def _calc_signature(self, params, *args):
        boto.log.debug('using _calc_signature_0')
        hmac = self._hmac.copy()
        s = params['Action'] + params['Timestamp']
        hmac.update(s)
        keys = params.keys()
        keys.sort(cmp = lambda x, y: cmp(x.lower(), y.lower()))
        pairs = []
        for key in keys:
            val = boto.utils.get_utf8_value(params[key])
            pairs.append(key + '=' + urllib.quote(val))
        qs = '&'.join(pairs)
        return (qs, base64.b64encode(hmac.digest()))

class QuerySignatureV1AuthHandler(QuerySignatureHelper, AuthHandler):
    """
Provides Query Signature V1 Authentication.
"""

    SignatureVersion = 1
    capability = ['sign-v1', 'mturk']

    def _calc_signature(self, params, *args):
        boto.log.debug('using _calc_signature_1')
        hmac = self._hmac.copy()
        keys = params.keys()
        keys.sort(cmp = lambda x, y: cmp(x.lower(), y.lower()))
        pairs = []
        for key in keys:
            hmac.update(key)
            val = boto.utils.get_utf8_value(params[key])
            hmac.update(val)
            pairs.append(key + '=' + urllib.quote(val))
        qs = '&'.join(pairs)
        return (qs, base64.b64encode(hmac.digest()))

class QuerySignatureV2AuthHandler(QuerySignatureHelper, AuthHandler):
    """Provides Query Signature V2 Authentication."""

    SignatureVersion = 2
    capability = ['sign-v2', 'ec2', 'ec2', 'emr', 'fps', 'ecs',
                  'sdb', 'iam', 'rds', 'sns', 'sqs', 'cloudformation']

    def _calc_signature(self, params, verb, path, server_name):
        boto.log.debug('using _calc_signature_2')
        string_to_sign = '%s\n%s\n%s\n' % (verb, server_name.lower(), path)
        if self._hmac_256:
            hmac = self._hmac_256.copy()
            params['SignatureMethod'] = 'HmacSHA256'
        else:
            hmac = self._hmac.copy()
            params['SignatureMethod'] = 'HmacSHA1'
        if self._provider.security_token:
            params['SecurityToken'] = self._provider.security_token
        keys = params.keys()
        keys.sort()
        pairs = []
        for key in keys:
            val = boto.utils.get_utf8_value(params[key])
            pairs.append(urllib.quote(key, safe='') + '=' +
                         urllib.quote(val, safe='-_~'))
        qs = '&'.join(pairs)
        boto.log.debug('query string: %s' % qs)
        string_to_sign += qs
        boto.log.debug('string_to_sign: %s' % string_to_sign)
        hmac.update(string_to_sign)
        b64 = base64.b64encode(hmac.digest())
        boto.log.debug('len(b64)=%d' % len(b64))
        boto.log.debug('base64 encoded digest: %s' % b64)
        return (qs, b64)


def get_auth_handler(host, config, provider, requested_capability=None):
    """Finds an AuthHandler that is ready to authenticate.

Lists through all the registered AuthHandlers to find one that is willing
to handle for the requested capabilities, config and provider.

:type host: string
:param host: The name of the host

:type config:
:param config:

:type provider:
:param provider:

Returns:
An implementation of AuthHandler.

Raises:
boto.exception.NoAuthHandlerFound:
boto.exception.TooManyAuthHandlerReadyToAuthenticate:
"""
    ready_handlers = []
    auth_handlers = boto.plugin.get_plugin(AuthHandler, requested_capability)
    total_handlers = len(auth_handlers)
    for handler in auth_handlers:
        try:
            ready_handlers.append(handler(host, config, provider))
        except boto.auth_handler.NotReadyToAuthenticate:
            pass
 
    if not ready_handlers:
        checked_handlers = auth_handlers
        names = [handler.__name__ for handler in checked_handlers]
        raise boto.exception.NoAuthHandlerFound(
              'No handler was ready to authenticate. %d handlers were checked.'
              ' %s '
              'Check your credentials' % (len(names), str(names)))

    if len(ready_handlers) > 1:
        # NOTE: Even though it would be nice to accept more than one handler
        # by using one of the many ready handlers, we are never sure that each
        # of them are referring to the same storage account. Since we cannot
        # easily guarantee that, it is always safe to fail, rather than operate
        # on the wrong account.
        names = [handler.__class__.__name__ for handler in ready_handlers]
        raise boto.exception.TooManyAuthHandlerReadyToAuthenticate(
               '%d AuthHandlers %s ready to authenticate for requested_capability '
               '%s, only 1 expected. This happens if you import multiple '
               'pluging.Plugin implementations that declare support for the '
               'requested_capability.' % (len(names), str(names),
               requested_capability))

    return ready_handlers[0]
Something went wrong with that request. Please try again.