scrapy/scrapy/utils/ssl.py

142 lines
4.7 KiB
Python

from __future__ import annotations
import logging
import ssl
from typing import TYPE_CHECKING, Any
import OpenSSL._util as pyOpenSSLutil
import OpenSSL.SSL
import OpenSSL.version
from scrapy.utils.python import to_unicode
if TYPE_CHECKING:
from OpenSSL.crypto import X509Name
from scrapy.settings import BaseSettings
logger = logging.getLogger(__name__)
# stdlib ssl module utils
# possible documented values for DOWNLOADER_CLIENT_TLS_METHOD
_STDLIB_PROTOCOL_MAP = {
"TLS": ssl.PROTOCOL_TLS_CLIENT,
"TLSv1.0": ssl.PROTOCOL_TLSv1,
"TLSv1.1": ssl.PROTOCOL_TLSv1_1,
"TLSv1.2": ssl.PROTOCOL_TLSv1_2,
}
def _make_ssl_context(settings: BaseSettings) -> ssl.SSLContext:
"""Create an :class:`ssl.SSLContext` instance according to the settings.
It's intended to be used in an HTTPS download handler.
"""
method_setting: str = settings["DOWNLOADER_CLIENT_TLS_METHOD"]
if method_setting not in _STDLIB_PROTOCOL_MAP:
raise ValueError(f"Unsupported TLS method: {method_setting}")
ciphers_setting: str | None = settings["DOWNLOADER_CLIENT_TLS_CIPHERS"]
verify_setting = settings.getbool("DOWNLOAD_VERIFY_CERTIFICATES")
ctx = ssl.SSLContext(_STDLIB_PROTOCOL_MAP[method_setting])
if verify_setting:
ctx.check_hostname = True
ctx.verify_mode = ssl.CERT_REQUIRED
ctx.load_default_certs()
else:
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE
if ciphers_setting:
ctx.set_ciphers(ciphers_setting)
return ctx
def _log_sslobj_debug_info(sslobj: ssl.SSLObject) -> None:
cipher = sslobj.cipher()
logger.debug(
f"SSL connection to {sslobj.server_hostname}"
f" using protocol {sslobj.version()},"
f" cipher {cipher[0] if cipher else None}"
)
# The peer certificate is unavailable on SSLObject unless peer
# certificate verification is enabled, which we don't want.
# pyOpenSSL utils
def ffi_buf_to_string(buf: Any) -> str:
return to_unicode(pyOpenSSLutil.ffi.string(buf))
def x509name_to_string(x509name: X509Name) -> str:
# from OpenSSL.crypto.X509Name.__repr__
result_buffer: Any = pyOpenSSLutil.ffi.new("char[]", 512)
pyOpenSSLutil.lib.X509_NAME_oneline(
x509name._name, result_buffer, len(result_buffer)
)
return ffi_buf_to_string(result_buffer)
def get_temp_key_info(ssl_object: Any) -> str | None:
# adapted from OpenSSL apps/s_cb.c::ssl_print_tmp_key()
if not hasattr(pyOpenSSLutil.lib, "SSL_get_server_tmp_key"):
# removed in cryptography 40.0.0
return None
temp_key_p = pyOpenSSLutil.ffi.new("EVP_PKEY **")
if not pyOpenSSLutil.lib.SSL_get_server_tmp_key(ssl_object, temp_key_p):
return None
temp_key = temp_key_p[0]
if temp_key == pyOpenSSLutil.ffi.NULL:
return None
temp_key = pyOpenSSLutil.ffi.gc(temp_key, pyOpenSSLutil.lib.EVP_PKEY_free)
key_info = []
key_type = pyOpenSSLutil.lib.EVP_PKEY_id(temp_key)
if key_type == pyOpenSSLutil.lib.EVP_PKEY_RSA:
key_info.append("RSA")
elif key_type == pyOpenSSLutil.lib.EVP_PKEY_DH:
key_info.append("DH")
elif key_type == pyOpenSSLutil.lib.EVP_PKEY_EC:
key_info.append("ECDH")
ec_key = pyOpenSSLutil.lib.EVP_PKEY_get1_EC_KEY(temp_key)
ec_key = pyOpenSSLutil.ffi.gc(ec_key, pyOpenSSLutil.lib.EC_KEY_free)
nid = pyOpenSSLutil.lib.EC_GROUP_get_curve_name(
pyOpenSSLutil.lib.EC_KEY_get0_group(ec_key)
)
cname = pyOpenSSLutil.lib.EC_curve_nid2nist(nid)
if cname == pyOpenSSLutil.ffi.NULL:
cname = pyOpenSSLutil.lib.OBJ_nid2sn(nid)
key_info.append(ffi_buf_to_string(cname))
else:
key_info.append(ffi_buf_to_string(pyOpenSSLutil.lib.OBJ_nid2sn(key_type)))
key_info.append(f"{pyOpenSSLutil.lib.EVP_PKEY_bits(temp_key)} bits")
return ", ".join(key_info)
def get_openssl_version() -> str:
system_openssl_bytes = OpenSSL.SSL.SSLeay_version(OpenSSL.SSL.SSLEAY_VERSION)
system_openssl = system_openssl_bytes.decode("ascii", errors="replace")
return f"{OpenSSL.version.__version__} ({system_openssl})"
def _log_ssl_conn_debug_info(hostname: str, connection: OpenSSL.SSL.Connection) -> None:
logger.debug(
"SSL connection to %s using protocol %s, cipher %s",
hostname,
connection.get_protocol_version_name(),
connection.get_cipher_name(),
)
server_cert = connection.get_peer_certificate()
if server_cert:
logger.debug(
'SSL connection certificate: issuer "%s", subject "%s"',
x509name_to_string(server_cert.get_issuer()),
x509name_to_string(server_cert.get_subject()),
)
key_info = get_temp_key_info(connection._ssl)
if key_info:
logger.debug("SSL temp key: %s", key_info)