gpt4 book ai didi

python - 用Scapy python识别telnet协议(protocol)

转载 作者:行者123 更新时间:2023-12-04 11:29:55 25 4
gpt4 key购买 nike

我正在用 Scapy 读取 Pcap 文件。如何识别在这个 pcap 文件中是否有使用 Telnet 协议(protocol)的数据包?
我看到只有当这些端口中的一个是 23 时,Scapy 才能将“telnet”写入 dport/sport,但是如果我使用另一个端口进行 Telnet,我如何通过 Scapy 识别这一点?

最佳答案

@TimRoberts 在评论中表示“Telnet 与其他 TCP 协议(protocol)没有区别。”这在某种程度上是正确的,因为所有 TCP 数据包都使用相同的结构,这在多个 Internet 工程任务组 (IETF) 征求意见 (RFC) 文档中进行了概述:

  • RFC 791 - Internet Protocol (IP)
  • RFC 793 - Transmission Control Protocol (TCP)

  • 这是 TCP 数据包的结构。
    enter image description here
    常见的应用协议(protocol)如超文本传输​​协议(protocol)(HTTP)、文件传输协议(protocol)(FTP)和 Telnet 都使用这种结构。
    关于应用协议(protocol) Telnet。正如您已经知道的,telnet 协议(protocol)的官方端口分配是端口 23。大多数供应商都遵守此端口标准,这就是为什么“只有当这些端口中有 1 个是 23 时,Scapy 才能将 'telnet' 写入 dport/sport”。
    这是使用端口 23 的 Telnet session 的 TCP 层:
    Layer TCP:
    Source Port: 1254
    Destination Port: 23
    Stream index: 0
    TCP Segment Len: 0
    Sequence number: 0 (relative sequence number)
    Sequence number (raw): 72603759
    Next sequence number: 1 (relative sequence number)
    Acknowledgment number: 0
    Acknowledgment number (raw): 0
    1010 .... = Header Length: 40 bytes (10)
    Flags: 0x002 (SYN)
    000. .... .... = Reserved: Not set
    ...0 .... .... = Nonce: Not set
    .... 0... .... = Congestion Window Reduced (CWR): Not set
    .... .0.. .... = ECN-Echo: Not set
    .... ..0. .... = Urgent: Not set
    .... ...0 .... = Acknowledgment: Not set
    .... .... 0... = Push: Not set
    .... .... .0.. = Reset: Not set
    .... .... ..1. = Syn: Set
    Expert Info (Chat/Sequence): Connection establish request (SYN): server port 23
    Connection establish request (SYN): server port 23
    Severity level: Chat
    Group: Sequence
    .... .... ...0 = Fin: Not set
    TCP Flags: \xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7S\xc2\xb7
    Window size value: 32120
    Calculated window size: 32120
    Checksum: 0x5d40 [unverified]
    Checksum Status: Unverified
    Urgent pointer: 0
    Options: (20 bytes), Maximum segment size, SACK permitted, Timestamps, No-Operation (NOP), Window scale
    TCP Option - Maximum segment size: 1460 bytes
    Kind: Maximum Segment Size (2)
    Length: 4
    MSS Value: 1460
    TCP Option - SACK permitted
    TCP Option - Timestamps: TSval 1444389, TSecr 0
    Timestamp value: 1444389
    Timestamp echo reply: 0
    TCP Option - No-Operation (NOP)
    TCP Option - Window scale: 0 (multiply by 1)
    Shift count: 0
    Multiplier: 1
    Timestamps
    Time since first frame in this TCP stream: 0.000000000 seconds
    Time since previous frame in this TCP stream: 0.000000000 seconds
    Kind: SACK Permitted (4)
    Kind: Time Stamp Option (8)
    Kind: No-Operation (1)
    Kind: Window Scale (3)
    Length: 2
    Length: 10
    Length: 3
    这是使用端口 3005 的 Telnet session 的 TCP 层:
    Layer TCP:
    Source Port: 52187
    Destination Port: 3005
    Stream index: 0
    TCP Segment Len: 0
    Sequence number: 0 (relative sequence number)
    Sequence number (raw): 1355255000
    Next sequence number: 1 (relative sequence number)
    Acknowledgment number: 0
    Acknowledgment number (raw): 0
    1011 .... = Header Length: 44 bytes (11)
    Flags: 0x002 (SYN)
    000. .... .... = Reserved: Not set
    ...0 .... .... = Nonce: Not set
    .... 0... .... = Congestion Window Reduced (CWR): Not set
    .... .0.. .... = ECN-Echo: Not set
    .... ..0. .... = Urgent: Not set
    .... ...0 .... = Acknowledgment: Not set
    .... .... 0... = Push: Not set
    .... .... .0.. = Reset: Not set
    .... .... ..1. = Syn: Set
    Expert Info (Chat/Sequence): Connection establish request (SYN): server port 3005
    Connection establish request (SYN): server port 3005
    Severity level: Chat
    Group: Sequence
    .... .... ...0 = Fin: Not set
    TCP Flags: \xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7S\xc2\xb7
    Window size value: 65535
    Calculated window size: 65535
    Checksum: 0x0afb [unverified]
    Checksum Status: Unverified
    Urgent pointer: 0
    Options: (24 bytes), Maximum segment size, No-Operation (NOP), Window scale, No-Operation (NOP), No-Operation (NOP), Timestamps, SACK permitted, End of Option List (EOL)
    TCP Option - Maximum segment size: 1460 bytes
    Kind: Maximum Segment Size (2)
    Length: 4
    MSS Value: 1460
    TCP Option - No-Operation (NOP)
    TCP Option - Window scale: 6 (multiply by 64)
    Shift count: 6
    Multiplier: 64
    TCP Option - Timestamps: TSval 3609205717, TSecr 0
    Timestamp value: 3609205717
    Timestamp echo reply: 0
    TCP Option - SACK permitted
    TCP Option - End of Option List (EOL)
    Timestamps
    Time since first frame in this TCP stream: 0.000000000 seconds
    Time since previous frame in this TCP stream: 0.000000000 seconds
    Kind: No-Operation (1)
    Kind: Window Scale (3)
    Kind: No-Operation (1)
    Kind: No-Operation (1)
    Kind: Time Stamp Option (8)
    Kind: SACK Permitted (4)
    Kind: End of Option List (0)
    Length: 3
    Length: 10
    Length: 2
    TCP Option - No-Operation (NOP)
    TCP Option - No-Operation (NOP)
    这是使用端口 21 的 FTP session 的 TCP 层:
    Layer TCP:
    Source Port: 35974
    Destination Port: 21
    Stream index: 0
    TCP Segment Len: 0
    Sequence number: 0 (relative sequence number)
    Sequence number (raw): 29473206
    Next sequence number: 1 (relative sequence number)
    Acknowledgment number: 0
    Acknowledgment number (raw): 0
    1010 .... = Header Length: 40 bytes (10)
    Flags: 0x002 (SYN)
    000. .... .... = Reserved: Not set
    ...0 .... .... = Nonce: Not set
    .... 0... .... = Congestion Window Reduced (CWR): Not set
    .... .0.. .... = ECN-Echo: Not set
    .... ..0. .... = Urgent: Not set
    .... ...0 .... = Acknowledgment: Not set
    .... .... 0... = Push: Not set
    .... .... .0.. = Reset: Not set
    .... .... ..1. = Syn: Set
    Expert Info (Chat/Sequence): Connection establish request (SYN): server port 21
    Connection establish request (SYN): server port 21
    Severity level: Chat
    Group: Sequence
    .... .... ...0 = Fin: Not set
    TCP Flags: \xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7S\xc2\xb7
    Window size value: 32648
    Calculated window size: 32648
    Checksum: 0x8fda [unverified]
    Checksum Status: Unverified
    Urgent pointer: 0
    Options: (20 bytes), Maximum segment size, No-Operation (NOP), Window scale, No-Operation (NOP), No-Operation (NOP), Timestamps
    TCP Option - Maximum segment size: 1380 bytes
    Kind: Maximum Segment Size (2)
    Length: 4
    MSS Value: 1380
    TCP Option - No-Operation (NOP)
    TCP Option - Window scale: 0 (multiply by 1)
    Shift count: 0
    Multiplier: 1
    TCP Option - Timestamps: TSval 1657560000, TSecr 0
    Timestamp value: 1657560000
    Timestamp echo reply: 0
    Timestamps
    Time since first frame in this TCP stream: 0.000000000 seconds
    Time since previous frame in this TCP stream: 0.000000000 seconds
    Kind: No-Operation (1)
    Kind: Window Scale (3)
    Kind: No-Operation (1)
    Kind: No-Operation (1)
    Kind: Time Stamp Option (8)
    Length: 3
    Length: 10
    TCP Option - No-Operation (NOP)
    TCP Option - No-Operation (NOP)
    这是使用端口 22 的 SSH session 的 TCP 层:
    Layer TCP:
    Source Port: 57732
    Destination Port: 22
    Stream index: 0
    TCP Segment Len: 0
    Sequence number: 0 (relative sequence number)
    Sequence number (raw): 71043058
    Next sequence number: 1 (relative sequence number)
    Acknowledgment number: 0
    Acknowledgment number (raw): 0
    1011 .... = Header Length: 44 bytes (11)
    Flags: 0x002 (SYN)
    000. .... .... = Reserved: Not set
    ...0 .... .... = Nonce: Not set
    .... 0... .... = Congestion Window Reduced (CWR): Not set
    .... .0.. .... = ECN-Echo: Not set
    .... ..0. .... = Urgent: Not set
    .... ...0 .... = Acknowledgment: Not set
    .... .... 0... = Push: Not set
    .... .... .0.. = Reset: Not set
    .... .... ..1. = Syn: Set
    Expert Info (Chat/Sequence): Connection establish request (SYN): server port 22
    Connection establish request (SYN): server port 22
    Severity level: Chat
    Group: Sequence
    .... .... ...0 = Fin: Not set
    TCP Flags: \xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7\xc2\xb7S\xc2\xb7
    Window size value: 65535
    Calculated window size: 65535
    Checksum: 0xd079 [unverified]
    Checksum Status: Unverified
    Urgent pointer: 0
    Options: (24 bytes), Maximum segment size, No-Operation (NOP), Window scale, No-Operation (NOP), No-Operation (NOP), Timestamps, SACK permitted, End of Option List (EOL)
    TCP Option - Maximum segment size: 1460 bytes
    Kind: Maximum Segment Size (2)
    Length: 4
    MSS Value: 1460
    TCP Option - No-Operation (NOP)
    TCP Option - Window scale: 6 (multiply by 64)
    Shift count: 6
    Multiplier: 64
    TCP Option - Timestamps: TSval 1452973307, TSecr 0
    Timestamp value: 1452973307
    Timestamp echo reply: 0
    TCP Option - SACK permitted
    TCP Option - End of Option List (EOL)
    Timestamps
    Time since first frame in this TCP stream: 0.000000000 seconds
    Time since previous frame in this TCP stream: 0.000000000 seconds
    Kind: No-Operation (1)
    Kind: Window Scale (3)
    Kind: No-Operation (1)
    Kind: No-Operation (1)
    Kind: Time Stamp Option (8)
    Kind: SACK Permitted (4)
    Kind: End of Option List (0)
    Length: 3
    Length: 10
    Length: 2
    TCP Option - No-Operation (NOP)
    TCP Option - No-Operation (NOP)
    如前所述,这些 TCP 层几乎无法区分。因此,尝试单独使用 TCP 层将很难确定端口 23 以外的端口上的 Telnet session 。因此,尝试使用 Scapy 来识别这些 session 而不进行更深入的数据包分析将非常困难。
    您可以潜在地分析 TCP 数据包的数据层以确定连接是否为 Telnet session 。除非您进行了某种程度的流量分析,否则这又需要付出大量的努力。
    使用 Python 模块 pyshark,您可以从数据层中提取内容。
    通过端口 23 的 Telnet session :
    import pyshark

    # the pcap is a Telnet session over port 23
    capture = pyshark.FileCapture('telnet-raw.pcap')
    for packet in capture:
    if hasattr(packet, 'tcp'):
    layers = packet.layers
    # 0 1 2 3
    # [<ETH Layer>, <IP Layer>, <TCP Layer>, <DATA Layer>]
    if len(layers) > 3:
    payload = packet.tcp.payload
    有效载荷输出为十六进制
    truncated...
    ff:fb:01:ff:fa:21:02:ff:f0:ff:fc:01

    ff:fd:01:ff:fe:01

    ff:fa:22:03:05:80:00:11:80:00:12:80:00:ff:f0

    0d:0a:4f:70:65:6e:42:53:44:2f:69:33:38:36:20:28:6f:6f:66:29:20:28:74:74:79:70:31:29:0d:0a:0d:0a

    6c:6f:67:69:6e:3a:20

    ff:fc:22:ff:fd:01
    truncated...
    输出中的第 4 个和第 5 个十六进制字符串是解密可能发生的 TCP 连接类型的重要部分。
    import binascii

    hex_data = '0d:0a:4f:70:65:6e:42:53:44:2f:69:33:38:36:20:28:6f:6f:66:29:20:28:74:74:79:70:31:29:0d:0a:0d:0a6c:6f:67:69:6e:3a:20 '
    hex_string = ' '.join(hex_data.split('0d:0a')).replace(':', '')
    hex_list = hex_string.split()
    for item in hex_list:
    decoded_string = binascii.unhexlify(item)
    print(decoded_string)
    # output
    b'OpenBSD/i386 (oof) (ttyp1)'
    b'login: '
    解码十六进制后,我们可以看到身份验证是通过端口 23 进行的。
    通过端口 3005 的 Telnet session :
    import pyshark

    # the pcap is a Telnet session over port 3005
    capture = pyshark.FileCapture('telnet-pcap-1.pcapng')
    for packet in capture:
    if hasattr(packet, 'tcp'):
    layers = packet.layers
    # 0 1 2 3
    # [<ETH Layer>, <IP Layer>, <TCP Layer>, <DATA Layer>]
    if len(layers) > 3:
    payload = packet.tcp.payload
    有效载荷输出为十六进制
    ff:fb:01:ff:fb:03:ff:fd:18:ff:fd:1f

    ff:fd:01:ff:fd:03:ff:fb:18:ff:fb:1f:ff:fa:1f:00:97:00:2f:ff:f0

    0d:0a:55:73:65:72:20:41:63:63:65:73:73:20:56:65:72:69:66:69:63:61:74:69:6f:6e:0d:0a:0d:0a:55:73:65:72:6e:61:6d:65:3a:20

    ff:fa:18:01:ff:f0

    ff:fa:18:00:58:54:45:52:4d:2d:32:35:36:43:4f:4c:4f:52:ff:f0
    truncated...
    输出中的第三个十六进制字符串是解密可能发生的 TCP 连接类型的重要部分。
    import binascii

    hex_data = '0d:0a:55:73:65:72:20:41:63:63:65:73:73:20:56:65:72:69:66:69:63:61:74:69:6f:6e:0d:0a:0d:0a:55:73:65:72:6e:61:6d:65:3a:20'

    # removing line breaks from the hex string
    hex_string = ' '.join(hex_data.split('0d:0a')).replace(':', '')
    hex_list = hex_string.split()
    for item in hex_list:
    decoded_string = binascii.unhexlify(item)
    print(decoded_string)
    # output
    b'User Access Verification'
    b'Username: '

    解码十六进制后,我们可以看到某种类型的身份验证正在端口 3005 上进行。需要额外的分析来确定此 session 是 Telnet session 还是某个其他 session 。

    关于python - 用Scapy python识别telnet协议(protocol),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/67404757/

    25 4 0
    Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
    广告合作:1813099741@qq.com 6ren.com