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150 lines
3.9 KiB
ReStructuredText
150 lines
3.9 KiB
ReStructuredText
.. role:: example-rule-emphasis
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SSH Keywords
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============
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Suricata has several rule keywords to match on different elements of SSH
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connections.
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ssh.proto
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---------
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Match on the version of the SSH protocol used. ``ssh.proto`` is a sticky buffer,
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and can be used as a fast pattern. ``ssh.proto`` replaces the previous buffer
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name: ``ssh_proto``. You may continue to use the previous name, but it's
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recommended that existing rules be converted to use the new name.
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Format::
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ssh.proto;
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Example:
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.. container:: example-rule
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alert ssh any any -> any any (msg:"match SSH protocol version"; :example-rule-emphasis:`ssh.proto;` content:"2.0"; sid:1000010;)
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The example above matches on SSH connections with SSH version 2.0.
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ssh.software
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------------
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Match on the software string from the SSH banner. ``ssh.software`` is a sticky
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buffer, and can be used as fast pattern.
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``ssh.software`` replaces the previous keyword names: ``ssh_software`` &
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``ssh.softwareversion``. You may continue to use the previous name, but it's
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recommended that rules be converted to use the new name.
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Format::
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ssh.software;
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Example:
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.. container:: example-rule
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alert ssh any any -> any any (msg:"match SSH software string"; :example-rule-emphasis:`ssh.software;` content:"openssh"; nocase; sid:1000020;)
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The example above matches on SSH connections where the software string contains
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"openssh".
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ssh.protoversion
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----------------
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Matches on the version of the SSH protocol used. A value of ``2_compat``
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includes SSH version 1.99.
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Format::
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ssh.protoversion:[0-9](\.[0-9])?|2_compat;
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Example:
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.. container:: example-rule
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alert ssh any any -> any any (msg:"SSH v2 compatible"; :example-rule-emphasis:`ssh.protoversion:2_compat;` sid:1;)
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The example above matches on SSH connections with SSH version 2 or 1.99.
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.. container:: example-rule
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alert ssh any any -> any any (msg:"SSH v1.10"; :example-rule-emphasis:`ssh.protoversion:1.10;` sid:1;)
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The example above matches on SSH connections with SSH version 1.10 only.
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ssh.softwareversion
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-------------------
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This keyword has been deprecated. Please use ``ssh.software`` instead. Matches
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on the software string from the SSH banner.
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Example:
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.. container:: example-rule
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alert ssh any any -> any any (msg:"match SSH software string"; :example-rule-emphasis:`ssh.softwareversion:"OpenSSH";` sid:10000040;)
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Suricata comes with a Hassh integration (https://github.com/salesforce/hassh). Hassh is used to fingerprint ssh clients and servers.
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Hassh must be enabled in the Suricata config file (set 'app-layer.protocols.ssh.hassh' to 'yes').
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ssh.hassh
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---------
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Match on hassh (md5 of of hassh algorithms of client).
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Example::
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alert ssh any any -> any any (msg:"match hassh"; \
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ssh.hassh; content:"ec7378c1a92f5a8dde7e8b7a1ddf33d1";\
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sid:1000010;)
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``ssh.hassh`` is a 'sticky buffer'.
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``ssh.hassh`` can be used as ``fast_pattern``.
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ssh.hassh.string
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----------------
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Match on Hassh string (hassh algorithms of client).
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Example::
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alert ssh any any -> any any (msg:"match hassh-string"; \
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ssh.hassh.string; content:"none,zlib@openssh.com,zlib"; \
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sid:1000030;)
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``ssh.hassh.string`` is a 'sticky buffer'.
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``ssh.hassh.string`` can be used as ``fast_pattern``.
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ssh.hassh.server
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----------------
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Match on hassh (md5 of hassh algorithms of server).
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Example::
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alert ssh any any -> any any (msg:"match SSH hash-server"; \
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ssh.hassh.server; content:"b12d2871a1189eff20364cf5333619ee"; \
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sid:1000020;)
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``ssh.hassh.server`` is a 'sticky buffer'.
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``ssh.hassh.server`` can be used as ``fast_pattern``.
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ssh.hassh.server.string
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-----------------------
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Match on hassh string (hassh algorithms of server).
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Example::
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alert ssh any any -> any any (msg:"match SSH hash-server-string"; \
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ssh.hassh.server.string; content:"umac-64-etm@openssh.com,umac-128-etm@openssh.com"; \
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sid:1000040;)
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``ssh.hassh.server.string`` is a 'sticky buffer'.
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``ssh.hassh.server.string`` can be used as ``fast_pattern``.
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