| 1 | # SPDX-License-Identifier: MIT |
| 2 | """ |
| 3 | SecureTranport support for urllib3 via ctypes. |
| 4 | |
| 5 | This makes platform-native TLS available to urllib3 users on macOS without the |
| 6 | use of a compiler. This is an important feature because the Python Package |
| 7 | Index is moving to become a TLSv1.2-or-higher server, and the default OpenSSL |
| 8 | that ships with macOS is not capable of doing TLSv1.2. The only way to resolve |
| 9 | this is to give macOS users an alternative solution to the problem, and that |
| 10 | solution is to use SecureTransport. |
| 11 | |
| 12 | We use ctypes here because this solution must not require a compiler. That's |
| 13 | because pip is not allowed to require a compiler either. |
| 14 | |
| 15 | This is not intended to be a seriously long-term solution to this problem. |
| 16 | The hope is that PEP 543 will eventually solve this issue for us, at which |
| 17 | point we can retire this contrib module. But in the short term, we need to |
| 18 | solve the impending tire fire that is Python on Mac without this kind of |
| 19 | contrib module. So...here we are. |
| 20 | |
| 21 | To use this module, simply import and inject it:: |
| 22 | |
| 23 | import urllib3.contrib.securetransport |
| 24 | urllib3.contrib.securetransport.inject_into_urllib3() |
| 25 | |
| 26 | Happy TLSing! |
| 27 | """ |
| 28 | from __future__ import absolute_import |
| 29 | |
| 30 | import contextlib |
| 31 | import ctypes |
| 32 | import errno |
| 33 | import os.path |
| 34 | import shutil |
| 35 | import socket |
| 36 | import ssl |
| 37 | import threading |
| 38 | import weakref |
| 39 | |
| 40 | from .. import util |
| 41 | from ._securetransport.bindings import ( |
| 42 | Security, SecurityConst, CoreFoundation |
| 43 | ) |
| 44 | from ._securetransport.low_level import ( |
| 45 | _assert_no_error, _cert_array_from_pem, _temporary_keychain, |
| 46 | _load_client_cert_chain |
| 47 | ) |
| 48 | |
| 49 | try: # Platform-specific: Python 2 |
| 50 | from socket import _fileobject |
| 51 | except ImportError: # Platform-specific: Python 3 |
| 52 | _fileobject = None |
| 53 | from ..packages.backports.makefile import backport_makefile |
| 54 | |
| 55 | try: |
| 56 | memoryview(b'') |
| 57 | except NameError: |
| 58 | raise ImportError("SecureTransport only works on Pythons with memoryview") |
| 59 | |
| 60 | __all__ = ['inject_into_urllib3', 'extract_from_urllib3'] |
| 61 | |
| 62 | # SNI always works |
| 63 | HAS_SNI = True |
| 64 | |
| 65 | orig_util_HAS_SNI = util.HAS_SNI |
| 66 | orig_util_SSLContext = util.ssl_.SSLContext |
| 67 | |
| 68 | # This dictionary is used by the read callback to obtain a handle to the |
| 69 | # calling wrapped socket. This is a pretty silly approach, but for now it'll |
| 70 | # do. I feel like I should be able to smuggle a handle to the wrapped socket |
| 71 | # directly in the SSLConnectionRef, but for now this approach will work I |
| 72 | # guess. |
| 73 | # |
| 74 | # We need to lock around this structure for inserts, but we don't do it for |
| 75 | # reads/writes in the callbacks. The reasoning here goes as follows: |
| 76 | # |
| 77 | # 1. It is not possible to call into the callbacks before the dictionary is |
| 78 | # populated, so once in the callback the id must be in the dictionary. |
| 79 | # 2. The callbacks don't mutate the dictionary, they only read from it, and |
| 80 | # so cannot conflict with any of the insertions. |
| 81 | # |
| 82 | # This is good: if we had to lock in the callbacks we'd drastically slow down |
| 83 | # the performance of this code. |
| 84 | _connection_refs = weakref.WeakValueDictionary() |
| 85 | _connection_ref_lock = threading.Lock() |
| 86 | |
| 87 | # Limit writes to 16kB. This is OpenSSL's limit, but we'll cargo-cult it over |
| 88 | # for no better reason than we need *a* limit, and this one is right there. |
| 89 | SSL_WRITE_BLOCKSIZE = 16384 |
| 90 | |
| 91 | # This is our equivalent of util.ssl_.DEFAULT_CIPHERS, but expanded out to |
| 92 | # individual cipher suites. We need to do this becuase this is how |
| 93 | # SecureTransport wants them. |
| 94 | CIPHER_SUITES = [ |
| 95 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, |
| 96 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, |
| 97 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, |
| 98 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, |
| 99 | SecurityConst.TLS_DHE_DSS_WITH_AES_256_GCM_SHA384, |
| 100 | SecurityConst.TLS_DHE_RSA_WITH_AES_256_GCM_SHA384, |
| 101 | SecurityConst.TLS_DHE_DSS_WITH_AES_128_GCM_SHA256, |
| 102 | SecurityConst.TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, |
| 103 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, |
| 104 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, |
| 105 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA, |
| 106 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA, |
| 107 | SecurityConst.TLS_DHE_RSA_WITH_AES_256_CBC_SHA256, |
| 108 | SecurityConst.TLS_DHE_DSS_WITH_AES_256_CBC_SHA256, |
| 109 | SecurityConst.TLS_DHE_RSA_WITH_AES_256_CBC_SHA, |
| 110 | SecurityConst.TLS_DHE_DSS_WITH_AES_256_CBC_SHA, |
| 111 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, |
| 112 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, |
| 113 | SecurityConst.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, |
| 114 | SecurityConst.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, |
| 115 | SecurityConst.TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, |
| 116 | SecurityConst.TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, |
| 117 | SecurityConst.TLS_DHE_RSA_WITH_AES_128_CBC_SHA, |
| 118 | SecurityConst.TLS_DHE_DSS_WITH_AES_128_CBC_SHA, |
| 119 | SecurityConst.TLS_RSA_WITH_AES_256_GCM_SHA384, |
| 120 | SecurityConst.TLS_RSA_WITH_AES_128_GCM_SHA256, |
| 121 | SecurityConst.TLS_RSA_WITH_AES_256_CBC_SHA256, |
| 122 | SecurityConst.TLS_RSA_WITH_AES_128_CBC_SHA256, |
| 123 | SecurityConst.TLS_RSA_WITH_AES_256_CBC_SHA, |
| 124 | SecurityConst.TLS_RSA_WITH_AES_128_CBC_SHA, |
| 125 | ] |
| 126 | |
| 127 | # Basically this is simple: for PROTOCOL_SSLv23 we turn it into a low of |
| 128 | # TLSv1 and a high of TLSv1.2. For everything else, we pin to that version. |
| 129 | _protocol_to_min_max = { |
| 130 | ssl.PROTOCOL_SSLv23: (SecurityConst.kTLSProtocol1, SecurityConst.kTLSProtocol12), |
| 131 | } |
| 132 | |
| 133 | if hasattr(ssl, "PROTOCOL_SSLv2"): |
| 134 | _protocol_to_min_max[ssl.PROTOCOL_SSLv2] = ( |
| 135 | SecurityConst.kSSLProtocol2, SecurityConst.kSSLProtocol2 |
| 136 | ) |
| 137 | if hasattr(ssl, "PROTOCOL_SSLv3"): |
| 138 | _protocol_to_min_max[ssl.PROTOCOL_SSLv3] = ( |
| 139 | SecurityConst.kSSLProtocol3, SecurityConst.kSSLProtocol3 |
| 140 | ) |
| 141 | if hasattr(ssl, "PROTOCOL_TLSv1"): |
| 142 | _protocol_to_min_max[ssl.PROTOCOL_TLSv1] = ( |
| 143 | SecurityConst.kTLSProtocol1, SecurityConst.kTLSProtocol1 |
| 144 | ) |
| 145 | if hasattr(ssl, "PROTOCOL_TLSv1_1"): |
| 146 | _protocol_to_min_max[ssl.PROTOCOL_TLSv1_1] = ( |
| 147 | SecurityConst.kTLSProtocol11, SecurityConst.kTLSProtocol11 |
| 148 | ) |
| 149 | if hasattr(ssl, "PROTOCOL_TLSv1_2"): |
| 150 | _protocol_to_min_max[ssl.PROTOCOL_TLSv1_2] = ( |
| 151 | SecurityConst.kTLSProtocol12, SecurityConst.kTLSProtocol12 |
| 152 | ) |
| 153 | if hasattr(ssl, "PROTOCOL_TLS"): |
| 154 | _protocol_to_min_max[ssl.PROTOCOL_TLS] = _protocol_to_min_max[ssl.PROTOCOL_SSLv23] |
| 155 | |
| 156 | |
| 157 | def inject_into_urllib3(): |
| 158 | """ |
| 159 | Monkey-patch urllib3 with SecureTransport-backed SSL-support. |
| 160 | """ |
| 161 | util.ssl_.SSLContext = SecureTransportContext |
| 162 | util.HAS_SNI = HAS_SNI |
| 163 | util.ssl_.HAS_SNI = HAS_SNI |
| 164 | util.IS_SECURETRANSPORT = True |
| 165 | util.ssl_.IS_SECURETRANSPORT = True |
| 166 | |
| 167 | |
| 168 | def extract_from_urllib3(): |
| 169 | """ |
| 170 | Undo monkey-patching by :func:`inject_into_urllib3`. |
| 171 | """ |
| 172 | util.ssl_.SSLContext = orig_util_SSLContext |
| 173 | util.HAS_SNI = orig_util_HAS_SNI |
| 174 | util.ssl_.HAS_SNI = orig_util_HAS_SNI |
| 175 | util.IS_SECURETRANSPORT = False |
| 176 | util.ssl_.IS_SECURETRANSPORT = False |
| 177 | |
| 178 | |
| 179 | def _read_callback(connection_id, data_buffer, data_length_pointer): |
| 180 | """ |
| 181 | SecureTransport read callback. This is called by ST to request that data |
| 182 | be returned from the socket. |
| 183 | """ |
| 184 | wrapped_socket = None |
| 185 | try: |
| 186 | wrapped_socket = _connection_refs.get(connection_id) |
| 187 | if wrapped_socket is None: |
| 188 | return SecurityConst.errSSLInternal |
| 189 | base_socket = wrapped_socket.socket |
| 190 | |
| 191 | requested_length = data_length_pointer[0] |
| 192 | |
| 193 | timeout = wrapped_socket.gettimeout() |
| 194 | error = None |
| 195 | read_count = 0 |
| 196 | buffer = (ctypes.c_char * requested_length).from_address(data_buffer) |
| 197 | buffer_view = memoryview(buffer) |
| 198 | |
| 199 | try: |
| 200 | while read_count < requested_length: |
| 201 | if timeout is None or timeout >= 0: |
| 202 | readables = util.wait_for_read([base_socket], timeout) |
| 203 | if not readables: |
| 204 | raise socket.error(errno.EAGAIN, 'timed out') |
| 205 | |
| 206 | # We need to tell ctypes that we have a buffer that can be |
| 207 | # written to. Upsettingly, we do that like this: |
| 208 | chunk_size = base_socket.recv_into( |
| 209 | buffer_view[read_count:requested_length] |
| 210 | ) |
| 211 | read_count += chunk_size |
| 212 | if not chunk_size: |
| 213 | if not read_count: |
| 214 | return SecurityConst.errSSLClosedGraceful |
| 215 | break |
| 216 | except (socket.error) as e: |
| 217 | error = e.errno |
| 218 | |
| 219 | if error is not None and error != errno.EAGAIN: |
| 220 | if error == errno.ECONNRESET: |
| 221 | return SecurityConst.errSSLClosedAbort |
| 222 | raise |
| 223 | |
| 224 | data_length_pointer[0] = read_count |
| 225 | |
| 226 | if read_count != requested_length: |
| 227 | return SecurityConst.errSSLWouldBlock |
| 228 | |
| 229 | return 0 |
| 230 | except Exception as e: |
| 231 | if wrapped_socket is not None: |
| 232 | wrapped_socket._exception = e |
| 233 | return SecurityConst.errSSLInternal |
| 234 | |
| 235 | |
| 236 | def _write_callback(connection_id, data_buffer, data_length_pointer): |
| 237 | """ |
| 238 | SecureTransport write callback. This is called by ST to request that data |
| 239 | actually be sent on the network. |
| 240 | """ |
| 241 | wrapped_socket = None |
| 242 | try: |
| 243 | wrapped_socket = _connection_refs.get(connection_id) |
| 244 | if wrapped_socket is None: |
| 245 | return SecurityConst.errSSLInternal |
| 246 | base_socket = wrapped_socket.socket |
| 247 | |
| 248 | bytes_to_write = data_length_pointer[0] |
| 249 | data = ctypes.string_at(data_buffer, bytes_to_write) |
| 250 | |
| 251 | timeout = wrapped_socket.gettimeout() |
| 252 | error = None |
| 253 | sent = 0 |
| 254 | |
| 255 | try: |
| 256 | while sent < bytes_to_write: |
| 257 | if timeout is None or timeout >= 0: |
| 258 | writables = util.wait_for_write([base_socket], timeout) |
| 259 | if not writables: |
| 260 | raise socket.error(errno.EAGAIN, 'timed out') |
| 261 | chunk_sent = base_socket.send(data) |
| 262 | sent += chunk_sent |
| 263 | |
| 264 | # This has some needless copying here, but I'm not sure there's |
| 265 | # much value in optimising this data path. |
| 266 | data = data[chunk_sent:] |
| 267 | except (socket.error) as e: |
| 268 | error = e.errno |
| 269 | |
| 270 | if error is not None and error != errno.EAGAIN: |
| 271 | if error == errno.ECONNRESET: |
| 272 | return SecurityConst.errSSLClosedAbort |
| 273 | raise |
| 274 | |
| 275 | data_length_pointer[0] = sent |
| 276 | if sent != bytes_to_write: |
| 277 | return SecurityConst.errSSLWouldBlock |
| 278 | |
| 279 | return 0 |
| 280 | except Exception as e: |
| 281 | if wrapped_socket is not None: |
| 282 | wrapped_socket._exception = e |
| 283 | return SecurityConst.errSSLInternal |
| 284 | |
| 285 | |
| 286 | # We need to keep these two objects references alive: if they get GC'd while |
| 287 | # in use then SecureTransport could attempt to call a function that is in freed |
| 288 | # memory. That would be...uh...bad. Yeah, that's the word. Bad. |
| 289 | _read_callback_pointer = Security.SSLReadFunc(_read_callback) |
| 290 | _write_callback_pointer = Security.SSLWriteFunc(_write_callback) |
| 291 | |
| 292 | |
| 293 | class WrappedSocket(object): |
| 294 | """ |
| 295 | API-compatibility wrapper for Python's OpenSSL wrapped socket object. |
| 296 | |
| 297 | Note: _makefile_refs, _drop(), and _reuse() are needed for the garbage |
| 298 | collector of PyPy. |
| 299 | """ |
| 300 | def __init__(self, socket): |
| 301 | self.socket = socket |
| 302 | self.context = None |
| 303 | self._makefile_refs = 0 |
| 304 | self._closed = False |
| 305 | self._exception = None |
| 306 | self._keychain = None |
| 307 | self._keychain_dir = None |
| 308 | self._client_cert_chain = None |
| 309 | |
| 310 | # We save off the previously-configured timeout and then set it to |
| 311 | # zero. This is done because we use select and friends to handle the |
| 312 | # timeouts, but if we leave the timeout set on the lower socket then |
| 313 | # Python will "kindly" call select on that socket again for us. Avoid |
| 314 | # that by forcing the timeout to zero. |
| 315 | self._timeout = self.socket.gettimeout() |
| 316 | self.socket.settimeout(0) |
| 317 | |
| 318 | @contextlib.contextmanager |
| 319 | def _raise_on_error(self): |
| 320 | """ |
| 321 | A context manager that can be used to wrap calls that do I/O from |
| 322 | SecureTransport. If any of the I/O callbacks hit an exception, this |
| 323 | context manager will correctly propagate the exception after the fact. |
| 324 | This avoids silently swallowing those exceptions. |
| 325 | |
| 326 | It also correctly forces the socket closed. |
| 327 | """ |
| 328 | self._exception = None |
| 329 | |
| 330 | # We explicitly don't catch around this yield because in the unlikely |
| 331 | # event that an exception was hit in the block we don't want to swallow |
| 332 | # it. |
| 333 | yield |
| 334 | if self._exception is not None: |
| 335 | exception, self._exception = self._exception, None |
| 336 | self.close() |
| 337 | raise exception |
| 338 | |
| 339 | def _set_ciphers(self): |
| 340 | """ |
| 341 | Sets up the allowed ciphers. By default this matches the set in |
| 342 | util.ssl_.DEFAULT_CIPHERS, at least as supported by macOS. This is done |
| 343 | custom and doesn't allow changing at this time, mostly because parsing |
| 344 | OpenSSL cipher strings is going to be a freaking nightmare. |
| 345 | """ |
| 346 | ciphers = (Security.SSLCipherSuite * len(CIPHER_SUITES))(*CIPHER_SUITES) |
| 347 | result = Security.SSLSetEnabledCiphers( |
| 348 | self.context, ciphers, len(CIPHER_SUITES) |
| 349 | ) |
| 350 | _assert_no_error(result) |
| 351 | |
| 352 | def _custom_validate(self, verify, trust_bundle): |
| 353 | """ |
| 354 | Called when we have set custom validation. We do this in two cases: |
| 355 | first, when cert validation is entirely disabled; and second, when |
| 356 | using a custom trust DB. |
| 357 | """ |
| 358 | # If we disabled cert validation, just say: cool. |
| 359 | if not verify: |
| 360 | return |
| 361 | |
| 362 | # We want data in memory, so load it up. |
| 363 | if os.path.isfile(trust_bundle): |
| 364 | with open(trust_bundle, 'rb') as f: |
| 365 | trust_bundle = f.read() |
| 366 | |
| 367 | cert_array = None |
| 368 | trust = Security.SecTrustRef() |
| 369 | |
| 370 | try: |
| 371 | # Get a CFArray that contains the certs we want. |
| 372 | cert_array = _cert_array_from_pem(trust_bundle) |
| 373 | |
| 374 | # Ok, now the hard part. We want to get the SecTrustRef that ST has |
| 375 | # created for this connection, shove our CAs into it, tell ST to |
| 376 | # ignore everything else it knows, and then ask if it can build a |
| 377 | # chain. This is a buuuunch of code. |
| 378 | result = Security.SSLCopyPeerTrust( |
| 379 | self.context, ctypes.byref(trust) |
| 380 | ) |
| 381 | _assert_no_error(result) |
| 382 | if not trust: |
| 383 | raise ssl.SSLError("Failed to copy trust reference") |
| 384 | |
| 385 | result = Security.SecTrustSetAnchorCertificates(trust, cert_array) |
| 386 | _assert_no_error(result) |
| 387 | |
| 388 | result = Security.SecTrustSetAnchorCertificatesOnly(trust, True) |
| 389 | _assert_no_error(result) |
| 390 | |
| 391 | trust_result = Security.SecTrustResultType() |
| 392 | result = Security.SecTrustEvaluate( |
| 393 | trust, ctypes.byref(trust_result) |
| 394 | ) |
| 395 | _assert_no_error(result) |
| 396 | finally: |
| 397 | if trust: |
| 398 | CoreFoundation.CFRelease(trust) |
| 399 | |
| 400 | if cert_array is None: |
| 401 | CoreFoundation.CFRelease(cert_array) |
| 402 | |
| 403 | # Ok, now we can look at what the result was. |
| 404 | successes = ( |
| 405 | SecurityConst.kSecTrustResultUnspecified, |
| 406 | SecurityConst.kSecTrustResultProceed |
| 407 | ) |
| 408 | if trust_result.value not in successes: |
| 409 | raise ssl.SSLError( |
| 410 | "certificate verify failed, error code: %d" % |
| 411 | trust_result.value |
| 412 | ) |
| 413 | |
| 414 | def handshake(self, |
| 415 | server_hostname, |
| 416 | verify, |
| 417 | trust_bundle, |
| 418 | min_version, |
| 419 | max_version, |
| 420 | client_cert, |
| 421 | client_key, |
| 422 | client_key_passphrase): |
| 423 | """ |
| 424 | Actually performs the TLS handshake. This is run automatically by |
| 425 | wrapped socket, and shouldn't be needed in user code. |
| 426 | """ |
| 427 | # First, we do the initial bits of connection setup. We need to create |
| 428 | # a context, set its I/O funcs, and set the connection reference. |
| 429 | self.context = Security.SSLCreateContext( |
| 430 | None, SecurityConst.kSSLClientSide, SecurityConst.kSSLStreamType |
| 431 | ) |
| 432 | result = Security.SSLSetIOFuncs( |
| 433 | self.context, _read_callback_pointer, _write_callback_pointer |
| 434 | ) |
| 435 | _assert_no_error(result) |
| 436 | |
| 437 | # Here we need to compute the handle to use. We do this by taking the |
| 438 | # id of self modulo 2**31 - 1. If this is already in the dictionary, we |
| 439 | # just keep incrementing by one until we find a free space. |
| 440 | with _connection_ref_lock: |
| 441 | handle = id(self) % 2147483647 |
| 442 | while handle in _connection_refs: |
| 443 | handle = (handle + 1) % 2147483647 |
| 444 | _connection_refs[handle] = self |
| 445 | |
| 446 | result = Security.SSLSetConnection(self.context, handle) |
| 447 | _assert_no_error(result) |
| 448 | |
| 449 | # If we have a server hostname, we should set that too. |
| 450 | if server_hostname: |
| 451 | if not isinstance(server_hostname, bytes): |
| 452 | server_hostname = server_hostname.encode('utf-8') |
| 453 | |
| 454 | result = Security.SSLSetPeerDomainName( |
| 455 | self.context, server_hostname, len(server_hostname) |
| 456 | ) |
| 457 | _assert_no_error(result) |
| 458 | |
| 459 | # Setup the ciphers. |
| 460 | self._set_ciphers() |
| 461 | |
| 462 | # Set the minimum and maximum TLS versions. |
| 463 | result = Security.SSLSetProtocolVersionMin(self.context, min_version) |
| 464 | _assert_no_error(result) |
| 465 | result = Security.SSLSetProtocolVersionMax(self.context, max_version) |
| 466 | _assert_no_error(result) |
| 467 | |
| 468 | # If there's a trust DB, we need to use it. We do that by telling |
| 469 | # SecureTransport to break on server auth. We also do that if we don't |
| 470 | # want to validate the certs at all: we just won't actually do any |
| 471 | # authing in that case. |
| 472 | if not verify or trust_bundle is not None: |
| 473 | result = Security.SSLSetSessionOption( |
| 474 | self.context, |
| 475 | SecurityConst.kSSLSessionOptionBreakOnServerAuth, |
| 476 | True |
| 477 | ) |
| 478 | _assert_no_error(result) |
| 479 | |
| 480 | # If there's a client cert, we need to use it. |
| 481 | if client_cert: |
| 482 | self._keychain, self._keychain_dir = _temporary_keychain() |
| 483 | self._client_cert_chain = _load_client_cert_chain( |
| 484 | self._keychain, client_cert, client_key |
| 485 | ) |
| 486 | result = Security.SSLSetCertificate( |
| 487 | self.context, self._client_cert_chain |
| 488 | ) |
| 489 | _assert_no_error(result) |
| 490 | |
| 491 | while True: |
| 492 | with self._raise_on_error(): |
| 493 | result = Security.SSLHandshake(self.context) |
| 494 | |
| 495 | if result == SecurityConst.errSSLWouldBlock: |
| 496 | raise socket.timeout("handshake timed out") |
| 497 | elif result == SecurityConst.errSSLServerAuthCompleted: |
| 498 | self._custom_validate(verify, trust_bundle) |
| 499 | continue |
| 500 | else: |
| 501 | _assert_no_error(result) |
| 502 | break |
| 503 | |
| 504 | def fileno(self): |
| 505 | return self.socket.fileno() |
| 506 | |
| 507 | # Copy-pasted from Python 3.5 source code |
| 508 | def _decref_socketios(self): |
| 509 | if self._makefile_refs > 0: |
| 510 | self._makefile_refs -= 1 |
| 511 | if self._closed: |
| 512 | self.close() |
| 513 | |
| 514 | def recv(self, bufsiz): |
| 515 | buffer = ctypes.create_string_buffer(bufsiz) |
| 516 | bytes_read = self.recv_into(buffer, bufsiz) |
| 517 | data = buffer[:bytes_read] |
| 518 | return data |
| 519 | |
| 520 | def recv_into(self, buffer, nbytes=None): |
| 521 | # Read short on EOF. |
| 522 | if self._closed: |
| 523 | return 0 |
| 524 | |
| 525 | if nbytes is None: |
| 526 | nbytes = len(buffer) |
| 527 | |
| 528 | buffer = (ctypes.c_char * nbytes).from_buffer(buffer) |
| 529 | processed_bytes = ctypes.c_size_t(0) |
| 530 | |
| 531 | with self._raise_on_error(): |
| 532 | result = Security.SSLRead( |
| 533 | self.context, buffer, nbytes, ctypes.byref(processed_bytes) |
| 534 | ) |
| 535 | |
| 536 | # There are some result codes that we want to treat as "not always |
| 537 | # errors". Specifically, those are errSSLWouldBlock, |
| 538 | # errSSLClosedGraceful, and errSSLClosedNoNotify. |
| 539 | if (result == SecurityConst.errSSLWouldBlock): |
| 540 | # If we didn't process any bytes, then this was just a time out. |
| 541 | # However, we can get errSSLWouldBlock in situations when we *did* |
| 542 | # read some data, and in those cases we should just read "short" |
| 543 | # and return. |
| 544 | if processed_bytes.value == 0: |
| 545 | # Timed out, no data read. |
| 546 | raise socket.timeout("recv timed out") |
| 547 | elif result in (SecurityConst.errSSLClosedGraceful, SecurityConst.errSSLClosedNoNotify): |
| 548 | # The remote peer has closed this connection. We should do so as |
| 549 | # well. Note that we don't actually return here because in |
| 550 | # principle this could actually be fired along with return data. |
| 551 | # It's unlikely though. |
| 552 | self.close() |
| 553 | else: |
| 554 | _assert_no_error(result) |
| 555 | |
| 556 | # Ok, we read and probably succeeded. We should return whatever data |
| 557 | # was actually read. |
| 558 | return processed_bytes.value |
| 559 | |
| 560 | def settimeout(self, timeout): |
| 561 | self._timeout = timeout |
| 562 | |
| 563 | def gettimeout(self): |
| 564 | return self._timeout |
| 565 | |
| 566 | def send(self, data): |
| 567 | processed_bytes = ctypes.c_size_t(0) |
| 568 | |
| 569 | with self._raise_on_error(): |
| 570 | result = Security.SSLWrite( |
| 571 | self.context, data, len(data), ctypes.byref(processed_bytes) |
| 572 | ) |
| 573 | |
| 574 | if result == SecurityConst.errSSLWouldBlock and processed_bytes.value == 0: |
| 575 | # Timed out |
| 576 | raise socket.timeout("send timed out") |
| 577 | else: |
| 578 | _assert_no_error(result) |
| 579 | |
| 580 | # We sent, and probably succeeded. Tell them how much we sent. |
| 581 | return processed_bytes.value |
| 582 | |
| 583 | def sendall(self, data): |
| 584 | total_sent = 0 |
| 585 | while total_sent < len(data): |
| 586 | sent = self.send(data[total_sent:total_sent + SSL_WRITE_BLOCKSIZE]) |
| 587 | total_sent += sent |
| 588 | |
| 589 | def shutdown(self): |
| 590 | with self._raise_on_error(): |
| 591 | Security.SSLClose(self.context) |
| 592 | |
| 593 | def close(self): |
| 594 | # TODO: should I do clean shutdown here? Do I have to? |
| 595 | if self._makefile_refs < 1: |
| 596 | self._closed = True |
| 597 | if self.context: |
| 598 | CoreFoundation.CFRelease(self.context) |
| 599 | self.context = None |
| 600 | if self._client_cert_chain: |
| 601 | CoreFoundation.CFRelease(self._client_cert_chain) |
| 602 | self._client_cert_chain = None |
| 603 | if self._keychain: |
| 604 | Security.SecKeychainDelete(self._keychain) |
| 605 | CoreFoundation.CFRelease(self._keychain) |
| 606 | shutil.rmtree(self._keychain_dir) |
| 607 | self._keychain = self._keychain_dir = None |
| 608 | return self.socket.close() |
| 609 | else: |
| 610 | self._makefile_refs -= 1 |
| 611 | |
| 612 | def getpeercert(self, binary_form=False): |
| 613 | # Urgh, annoying. |
| 614 | # |
| 615 | # Here's how we do this: |
| 616 | # |
| 617 | # 1. Call SSLCopyPeerTrust to get hold of the trust object for this |
| 618 | # connection. |
| 619 | # 2. Call SecTrustGetCertificateAtIndex for index 0 to get the leaf. |
| 620 | # 3. To get the CN, call SecCertificateCopyCommonName and process that |
| 621 | # string so that it's of the appropriate type. |
| 622 | # 4. To get the SAN, we need to do something a bit more complex: |
| 623 | # a. Call SecCertificateCopyValues to get the data, requesting |
| 624 | # kSecOIDSubjectAltName. |
| 625 | # b. Mess about with this dictionary to try to get the SANs out. |
| 626 | # |
| 627 | # This is gross. Really gross. It's going to be a few hundred LoC extra |
| 628 | # just to repeat something that SecureTransport can *already do*. So my |
| 629 | # operating assumption at this time is that what we want to do is |
| 630 | # instead to just flag to urllib3 that it shouldn't do its own hostname |
| 631 | # validation when using SecureTransport. |
| 632 | if not binary_form: |
| 633 | raise ValueError( |
| 634 | "SecureTransport only supports dumping binary certs" |
| 635 | ) |
| 636 | trust = Security.SecTrustRef() |
| 637 | certdata = None |
| 638 | der_bytes = None |
| 639 | |
| 640 | try: |
| 641 | # Grab the trust store. |
| 642 | result = Security.SSLCopyPeerTrust( |
| 643 | self.context, ctypes.byref(trust) |
| 644 | ) |
| 645 | _assert_no_error(result) |
| 646 | if not trust: |
| 647 | # Probably we haven't done the handshake yet. No biggie. |
| 648 | return None |
| 649 | |
| 650 | cert_count = Security.SecTrustGetCertificateCount(trust) |
| 651 | if not cert_count: |
| 652 | # Also a case that might happen if we haven't handshaked. |
| 653 | # Handshook? Handshaken? |
| 654 | return None |
| 655 | |
| 656 | leaf = Security.SecTrustGetCertificateAtIndex(trust, 0) |
| 657 | assert leaf |
| 658 | |
| 659 | # Ok, now we want the DER bytes. |
| 660 | certdata = Security.SecCertificateCopyData(leaf) |
| 661 | assert certdata |
| 662 | |
| 663 | data_length = CoreFoundation.CFDataGetLength(certdata) |
| 664 | data_buffer = CoreFoundation.CFDataGetBytePtr(certdata) |
| 665 | der_bytes = ctypes.string_at(data_buffer, data_length) |
| 666 | finally: |
| 667 | if certdata: |
| 668 | CoreFoundation.CFRelease(certdata) |
| 669 | if trust: |
| 670 | CoreFoundation.CFRelease(trust) |
| 671 | |
| 672 | return der_bytes |
| 673 | |
| 674 | def _reuse(self): |
| 675 | self._makefile_refs += 1 |
| 676 | |
| 677 | def _drop(self): |
| 678 | if self._makefile_refs < 1: |
| 679 | self.close() |
| 680 | else: |
| 681 | self._makefile_refs -= 1 |
| 682 | |
| 683 | |
| 684 | if _fileobject: # Platform-specific: Python 2 |
| 685 | def makefile(self, mode, bufsize=-1): |
| 686 | self._makefile_refs += 1 |
| 687 | return _fileobject(self, mode, bufsize, close=True) |
| 688 | else: # Platform-specific: Python 3 |
| 689 | def makefile(self, mode="r", buffering=None, *args, **kwargs): |
| 690 | # We disable buffering with SecureTransport because it conflicts with |
| 691 | # the buffering that ST does internally (see issue #1153 for more). |
| 692 | buffering = 0 |
| 693 | return backport_makefile(self, mode, buffering, *args, **kwargs) |
| 694 | |
| 695 | WrappedSocket.makefile = makefile |
| 696 | |
| 697 | |
| 698 | class SecureTransportContext(object): |
| 699 | """ |
| 700 | I am a wrapper class for the SecureTransport library, to translate the |
| 701 | interface of the standard library ``SSLContext`` object to calls into |
| 702 | SecureTransport. |
| 703 | """ |
| 704 | def __init__(self, protocol): |
| 705 | self._min_version, self._max_version = _protocol_to_min_max[protocol] |
| 706 | self._options = 0 |
| 707 | self._verify = False |
| 708 | self._trust_bundle = None |
| 709 | self._client_cert = None |
| 710 | self._client_key = None |
| 711 | self._client_key_passphrase = None |
| 712 | |
| 713 | @property |
| 714 | def check_hostname(self): |
| 715 | """ |
| 716 | SecureTransport cannot have its hostname checking disabled. For more, |
| 717 | see the comment on getpeercert() in this file. |
| 718 | """ |
| 719 | return True |
| 720 | |
| 721 | @check_hostname.setter |
| 722 | def check_hostname(self, value): |
| 723 | """ |
| 724 | SecureTransport cannot have its hostname checking disabled. For more, |
| 725 | see the comment on getpeercert() in this file. |
| 726 | """ |
| 727 | pass |
| 728 | |
| 729 | @property |
| 730 | def options(self): |
| 731 | # TODO: Well, crap. |
| 732 | # |
| 733 | # So this is the bit of the code that is the most likely to cause us |
| 734 | # trouble. Essentially we need to enumerate all of the SSL options that |
| 735 | # users might want to use and try to see if we can sensibly translate |
| 736 | # them, or whether we should just ignore them. |
| 737 | return self._options |
| 738 | |
| 739 | @options.setter |
| 740 | def options(self, value): |
| 741 | # TODO: Update in line with above. |
| 742 | self._options = value |
| 743 | |
| 744 | @property |
| 745 | def verify_mode(self): |
| 746 | return ssl.CERT_REQUIRED if self._verify else ssl.CERT_NONE |
| 747 | |
| 748 | @verify_mode.setter |
| 749 | def verify_mode(self, value): |
| 750 | self._verify = True if value == ssl.CERT_REQUIRED else False |
| 751 | |
| 752 | def set_default_verify_paths(self): |
| 753 | # So, this has to do something a bit weird. Specifically, what it does |
| 754 | # is nothing. |
| 755 | # |
| 756 | # This means that, if we had previously had load_verify_locations |
| 757 | # called, this does not undo that. We need to do that because it turns |
| 758 | # out that the rest of the urllib3 code will attempt to load the |
| 759 | # default verify paths if it hasn't been told about any paths, even if |
| 760 | # the context itself was sometime earlier. We resolve that by just |
| 761 | # ignoring it. |
| 762 | pass |
| 763 | |
| 764 | def load_default_certs(self): |
| 765 | return self.set_default_verify_paths() |
| 766 | |
| 767 | def set_ciphers(self, ciphers): |
| 768 | # For now, we just require the default cipher string. |
| 769 | if ciphers != util.ssl_.DEFAULT_CIPHERS: |
| 770 | raise ValueError( |
| 771 | "SecureTransport doesn't support custom cipher strings" |
| 772 | ) |
| 773 | |
| 774 | def load_verify_locations(self, cafile=None, capath=None, cadata=None): |
| 775 | # OK, we only really support cadata and cafile. |
| 776 | if capath is not None: |
| 777 | raise ValueError( |
| 778 | "SecureTransport does not support cert directories" |
| 779 | ) |
| 780 | |
| 781 | self._trust_bundle = cafile or cadata |
| 782 | |
| 783 | def load_cert_chain(self, certfile, keyfile=None, password=None): |
| 784 | self._client_cert = certfile |
| 785 | self._client_key = keyfile |
| 786 | self._client_cert_passphrase = password |
| 787 | |
| 788 | def wrap_socket(self, sock, server_side=False, |
| 789 | do_handshake_on_connect=True, suppress_ragged_eofs=True, |
| 790 | server_hostname=None): |
| 791 | # So, what do we do here? Firstly, we assert some properties. This is a |
| 792 | # stripped down shim, so there is some functionality we don't support. |
| 793 | # See PEP 543 for the real deal. |
| 794 | assert not server_side |
| 795 | assert do_handshake_on_connect |
| 796 | assert suppress_ragged_eofs |
| 797 | |
| 798 | # Ok, we're good to go. Now we want to create the wrapped socket object |
| 799 | # and store it in the appropriate place. |
| 800 | wrapped_socket = WrappedSocket(sock) |
| 801 | |
| 802 | # Now we can handshake |
| 803 | wrapped_socket.handshake( |
| 804 | server_hostname, self._verify, self._trust_bundle, |
| 805 | self._min_version, self._max_version, self._client_cert, |
| 806 | self._client_key, self._client_key_passphrase |
| 807 | ) |
| 808 | return wrapped_socket |