python2中requests.post能否做双向认证？需要的证书一般从哪里获得？

如题，纠结了好久了。用socket和openssl方式通过2各pem文件可以实现认证，但是换成requests.post方式就不行了。成功的函数如下：

def ssl_request(data=None):
    import OpenSSL
    ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD)
    ctx.use_certificate_file('/Users/username/Work/cert.pem')  # 证书
    ctx.use_privatekey_file('/Users/username/Work/key-unencrypted.pem')  # 密钥

    sock = socket.socket()
    ssock = OpenSSL.SSL.Connection(ctx, sock)
    ssock.connect(('123.456.789.111', 443))
    send_flag = 1
    while send_flag == 1:
        try:
            ssock.send(data)
            send_flag = 0
        except (OpenSSL.SSL.WantReadError, OpenSSL.SSL.WantWriteError):
            continue
    write_flag = 1
    while write_flag == 1:
        try:
            recv_data = ssock.recv(16384)
            write_flag = 0
        except (OpenSSL.SSL.WantReadError, OpenSSL.SSL.WantWriteError):
            continue
    sock.close()
    return recv_data

用request post做双向认证的错误是什么，是不是你的证书没有配置正确