如何列出静态链接的python版本中可用的所有openssl密码？

2条回答

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1楼 · 编辑于 2024-06-01 11:37:20

Jan-Philip Gehrcke's answer需要尚未发布的python版本才有用（请参阅注释），这使得回答有关较旧版本python的问题变得不实际。但这一段启发了我：

...you cannot call sslsock.shared_ciphers() before the socket is connected. Otherwise, Python's _ssl module does not create a low-level OpenSSL SSL object, which is needed to read the ciphers.

这让我想到了一个可能的解决办法。都在同一个python程序中：

创建接受任何密码的服务器套接字（ciphers='ALL:aNULL:eNULL'）。
使用配置有我们要检查的密码列表的客户端套接字连接到服务器套接字（如果我们要测试python 2.7.8中的默认值，请说'DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2'）
建立连接后，检查客户机实际选择的密码，并将其打印出来，例如'AES256-GCM-SHA384'。客户端将从其配置的密码列表中选择与服务器提供的密码匹配的最高优先级密码。服务器接受任何密码，并使用相同的OpenSSL库在同一个python程序中运行，因此服务器的列表保证是客户机列表的超集。因此，使用的密码必须是提供给客户端套接字的扩展列表中优先级最高的密码。万岁。
现在重复，再次连接到服务器套接字，但这次排除在前一轮中选择的密码，方法是将它的反项附加到客户端套接字的密码列表中，例如'DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:!AES256-GCM-SHA384'）
重复此操作，直到SSL握手失败，因为密码已用完。

下面是代码（也可用作a github gist）：

"""An attempt to produce similar output to "openssl ciphers -v", but for
python's built-in ssl.

To answer https://stackoverflow.com/q/28332448/445073
"""
from __future__ import print_function

import argparse
import logging
import multiprocessing
import os
import socket
import ssl
import sys

def server(log_level, queue):
    logging.basicConfig(level=log_level)
    logger = logging.getLogger("server")

    logger.debug("Creating bind socket")
    bind_sock = socket.socket()
    bind_sock.bind(('127.0.0.1', 0))
    bind_sock.listen(5)

    bind_addr = bind_sock.getsockname()
    logger.debug("Listening on %r", bind_addr)
    queue.put(bind_addr)

    while True:
        logger.debug("Waiting for connection")
        conn_sock, fromaddr = bind_sock.accept()
        conn_sock = ssl.wrap_socket(conn_sock,
                                    ssl_version=ssl.PROTOCOL_SSLv23,
                                    server_side=True,
                                    certfile="server.crt",
                                    keyfile="server.key",
                                    ciphers="ALL:aNULL:eNULL")

        data = conn_sock.read()
        logger.debug("Read %r", data)
        conn_sock.close()
    logger.debug("Done")

def parse_args(argv):
    parser = argparse.ArgumentParser(
        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument("--verbose", "-v", action="store_true",
                        help="Turn on debug logging")
    parser.add_argument("--ciphers", "-c",
                        default=ssl._DEFAULT_CIPHERS,
                        help="Cipher list to test. Defaults to this python's "
                        "default client list")
    args = parser.parse_args(argv[1:])
    return args

if __name__ == "__main__":
    args = parse_args(sys.argv)

    log_level = logging.DEBUG if args.verbose else logging.INFO

    logging.basicConfig(level=log_level)
    logger = logging.getLogger("client")

    if not os.path.isfile('server.crt') or not os.path.isfile('server.key'):
        print("Must generate server.crt and server.key before running")
        print("Try:")
        print("openssl req -x509 -newkey rsa:2048 -keyout server.key -out server.crt -nodes -days 365  -subj '/CN=127.0.0.1'")
        sys.exit(1)

    queue = multiprocessing.Queue()
    server_proc = multiprocessing.Process(target=server, args=(log_level, queue))
    server_proc.start()
    logger.debug("Waiting for server address")
    server_addr = queue.get()

    chosen_ciphers = []
    try:
        cipher_list = args.ciphers
        while True:
            client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            client_sock = ssl.wrap_socket(client_sock,
                                          ssl_version=ssl.PROTOCOL_SSLv23,
                                          ciphers=cipher_list)
            logger.debug("Connecting to %r", server_addr)
            client_sock.connect(server_addr)
            logger.debug("Connected")

            chosen_cipher = client_sock.cipher()
            chosen_ciphers.append(chosen_cipher)

            client_sock.write("ping")
            client_sock.close()

            # Exclude the first choice cipher from the list, to see what we get
            # next time.
            cipher_list += ':!' + chosen_cipher[0]
    except ssl.SSLError as err:
        if 'handshake failure' in str(err):
            logger.debug("Handshake failed - no more ciphers to try")
        else:
            logger.exception("Something bad happened")
    except Exception:
        logger.exception("Something bad happened")
    else:
        server_proc.join()
    finally:
        server_proc.terminate()

    print("Python: {}".format(sys.version))
    print("OpenSSL: {}".format(ssl.OPENSSL_VERSION))
    print("Expanding cipher list: {}".format(args.ciphers))
    print("{} ciphers found:".format(len(chosen_ciphers)))
    print("\n".join(repr(cipher) for cipher in chosen_ciphers))

请注意它默认如何测试python内置的默认密码列表：

day@laptop ~/test
$ python --version
Python 2.7.8

day@laptop ~/test
$ python ssltest.py -h
usage: ssltest.py [-h] [--verbose] [--ciphers CIPHERS]

optional arguments:
  -h, --help            show this help message and exit
  --verbose, -v         Turn on debug logging (default: False)
  --ciphers CIPHERS, -c CIPHERS
                        Cipher list to test. Defaults to this python's default
                        client list (default:
                        DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2)

因此，我们可以很容易地看到默认客户机密码列表扩展到什么，以及它如何从python 2.7.8更改为2.7.9：

day@laptop ~/test
$ ~/dists/python-2.7.8-with-pywin32-218-x86/python ssltest.py
Python: 2.7.8 (default, Jun 30 2014, 16:03:49) [MSC v.1500 32 bit (Intel)]
OpenSSL: OpenSSL 1.0.1h 5 Jun 2014
Expanding cipher list: DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2
12 ciphers found:
('AES256-GCM-SHA384', 'TLSv1/SSLv3', 256)
('AES256-SHA256', 'TLSv1/SSLv3', 256)
('AES256-SHA', 'TLSv1/SSLv3', 256)
('CAMELLIA256-SHA', 'TLSv1/SSLv3', 256)
('DES-CBC3-SHA', 'TLSv1/SSLv3', 168)
('AES128-GCM-SHA256', 'TLSv1/SSLv3', 128)
('AES128-SHA256', 'TLSv1/SSLv3', 128)
('AES128-SHA', 'TLSv1/SSLv3', 128)
('SEED-SHA', 'TLSv1/SSLv3', 128)
('CAMELLIA128-SHA', 'TLSv1/SSLv3', 128)
('RC4-SHA', 'TLSv1/SSLv3', 128)
('RC4-MD5', 'TLSv1/SSLv3', 128)

day@laptop ~/test
$ ~/dists/python-2.7.9-with-pywin32-219-x86/python ssltest.py
Python: 2.7.9 (default, Dec 10 2014, 12:24:55) [MSC v.1500 32 bit (Intel)]
OpenSSL: OpenSSL 1.0.1j 15 Oct 2014
Expanding cipher list: ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+HIGH:DH+HIGH:ECDH+3DES:DH+3DES:RSA+AESGCM:RSA+AES:RSA+HIGH:RSA+3DES:ECDH+RC4:DH+RC4:RSA+RC4:!aNULL:!eNULL:!MD5
18 ciphers found:
('ECDHE-RSA-AES256-GCM-SHA384', 'TLSv1/SSLv3', 256)
('ECDHE-RSA-AES128-GCM-SHA256', 'TLSv1/SSLv3', 128)
('ECDHE-RSA-AES256-SHA384', 'TLSv1/SSLv3', 256)
('ECDHE-RSA-AES256-SHA', 'TLSv1/SSLv3', 256)
('ECDHE-RSA-AES128-SHA256', 'TLSv1/SSLv3', 128)
('ECDHE-RSA-AES128-SHA', 'TLSv1/SSLv3', 128)
('ECDHE-RSA-DES-CBC3-SHA', 'TLSv1/SSLv3', 112)
('AES256-GCM-SHA384', 'TLSv1/SSLv3', 256)
('AES128-GCM-SHA256', 'TLSv1/SSLv3', 128)
('AES256-SHA256', 'TLSv1/SSLv3', 256)
('AES256-SHA', 'TLSv1/SSLv3', 256)
('AES128-SHA256', 'TLSv1/SSLv3', 128)
('AES128-SHA', 'TLSv1/SSLv3', 128)
('CAMELLIA256-SHA', 'TLSv1/SSLv3', 256)
('CAMELLIA128-SHA', 'TLSv1/SSLv3', 128)
('DES-CBC3-SHA', 'TLSv1/SSLv3', 112)
('ECDHE-RSA-RC4-SHA', 'TLSv1/SSLv3', 128)
('RC4-SHA', 'TLSv1/SSLv3', 128)

我想这回答了我的问题。除非有人发现这种方法有问题？

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2楼 · 编辑于 2024-06-01 11:37:20

您可能想在https://github.com/openssl/openssl/blob/master/apps/ciphers.c查看openssl cipher的源代码
关键步骤似乎是：
meth = SSLv23_server_method();
ctx = SSL_CTX_new(meth);
SSL_CTX_set_cipher_list(ctx, ciphers)，而ciphers是字符串
ssl = SSL_new(ctx);
sk = SSL_get1_supported_ciphers(ssl);
for (i = 0; i < sk_SSL_CIPHER_num(sk); i++) { print SSL_CIPHER_get_name(sk_SSL_CIPHER_value(sk, i)); }
Python 3.4中的SSL_CTX_set_cipher_list函数在上下文的set_ciphers方法中调用。您可以使用以下方法实现相同的目的：
import socket from ssl import SSLSocket sslsock = SSLSocket(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) sslsock.context.set_ciphers('DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2')
下一步是调用SSL_get1_supported_ciphers()，不幸的是，在Python的^{}中没有使用它。最接近的是SSLSocket实例的shared_ciphers()方法。当前的实现是
static PyObject *PySSL_shared_ciphers(PySSLSocket *self) { [...] ciphers = sess->ciphers; res = PyList_New(sk_SSL_CIPHER_num(ciphers)); for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) { PyObject *tup = cipher_to_tuple(sk_SSL_CIPHER_value(ciphers, i)); [...] PyList_SET_ITEM(res, i, tup); } return res; }
也就是说，这个循环与上面的ciphers.c实现非常相似，并返回密码的Python列表，其顺序与ciphers.c中的循环相同。
继续上面的sslsock = SSLSocket(...)示例，在连接套接字之前不能调用sslsock.shared_ciphers()。否则，Python的ssl模块不会创建低级opensslsl对象，这是读取密码所必需的。这与ciphers.c中的实现不同，后者创建一个低级SSL对象，而不需要连接。
这就是我所取得的进展，我希望这能有所帮助，也许你可以根据这些发现找出你所需要的。

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