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Feature #5234

closed

tls: subjectAltName buffer

Added by Genina Po about 3 years ago. Updated 16 days ago.

Status:
Closed
Priority:
Normal
Assignee:
Shivani Bhardwaj
Target version:
8.0.0-beta1
Effort:
Difficulty:
Label:

Description

Hi Team,

Does Suricata support parsing subjectAltName data into a SSL/TLS sticky buffer? If not, it would be a nice feature to have if the subjectAltName is present in SSL/TLS certificate or in the X509 extension.

The attached .pcap may be used to test this feature request.

Please note there is an observed inconsistency with how the subjectAltName is being parsed amongst Suricata engine versions.

If Suricata 6+ is used on the attached .pcap, the subjectAltName is parsed:
Suri7

issuerdn       C=XX, CN=mamzon.ru, L=XX, O=XX, OU=XX, ST=XX, Email=webmaster@mamzon.ru, subjectAltName=*.mamzon.ru www.mamzon.ru
sample: d08f862fc5830ad381db2027c10823c5

If Suricata 5 and below are used, the subjectAltName is not parsed:
Suri5 

'issuerdn': 'C=XX, CN=mamzon.ru/L=XX/O=XX/OU=XX/ST=XX/emailAddress=webmaster@mamzon.ru/unknown=*.mamzon.ru www.mamzon.ru',

Files

Download all files
d08f862fc5830ad381db2027c10823c5.pcap (1.53 MB) d08f862fc5830ad381db2027c10823c5.pcap Genina Po, 04/06/2022 11:22 PM
414db0257c6eb46.pcap (2.79 KB) 414db0257c6eb46.pcap Brandon Murphy, 04/03/2024 01:19 PM

Related issues 2 (1 open — 1 closed)

Related to Suricata - Task #4772: tracking: parity between fields logged and fields available for detectionAssignedVictor JulienActions
Related to Suricata - Optimization #6575: detect/multi-buffer: use single definition of struct PrefilterMpmKrb5NameClosedPhilippe AntoineActions
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 #1

Updated by Victor Julien over 2 years ago

  • Status changed from New to Assigned
  • Assignee changed from OISF Dev to Shivani Bhardwaj
  • Target version changed from TBD to 8.0.0-beta1
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 #2

Updated by Brandon Murphy over 2 years ago

An example of where Subject Alt Name Parsing would be handy is a pattern observed within Glupteba's new TLS certs

Reference: https://www.nozominetworks.com/blog/tracking-malicious-glupteba-activity-through-the-blockchain/

https://crt.sh/?q=4c2bac6c0493203dabaed2b14b99f2f8f17a9cab804a5ac6efd0e6415dbc568b

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 #3

Updated by Juliana Fajardini Reichow over 1 year ago

  • Related to Task #4772: tracking: parity between fields logged and fields available for detection added
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 #4

Updated by Shivani Bhardwaj about 1 year ago

  • Status changed from Assigned to In Progress
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 #5

Updated by Shivani Bhardwaj about 1 year ago

  • Status changed from In Progress to In Review
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 #6

Updated by Brandon Murphy about 1 year ago

@Shivani Bhardwaj

Do you know what the behavior of this keyword is when there are multiple entires in the subject alt name?

the cert referenced within the crt.sh link above is a good example.

I was wondering if this supported multi-buffer mode, or if they were concatenated together in some predictable format (http.header_names style), etc.

Thanks for you work on this issue!

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 #7

Updated by Brandon Murphy about 1 year ago

upload pcap of referenced crt.sh cert being sent to the client

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 #8

Updated by Philippe Antoine about 1 year ago

  • Related to Optimization #6575: detect/multi-buffer: use single definition of struct PrefilterMpmKrb5Name added
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 #9

Updated by Shivani Bhardwaj about 1 year ago

Do you know what the behavior of this keyword is when there are multiple entires in the subject alt name?

It traverses over all the subjectaltnames to find a match.
For example, for the pcap you have uploaded (Thank you! :) ), I see the following in the output and you should be able to alert against any of these.

"subjectaltname": [
      "server1.xn--j1ahhq.xn--p1ai",
      "server10.xn--j1ahhq.xn--p1ai",
      "server11.xn--j1ahhq.xn--p1ai",
      "server12.xn--j1ahhq.xn--p1ai",
      "server13.xn--j1ahhq.xn--p1ai",
      "server14.xn--j1ahhq.xn--p1ai",
      "server15.xn--j1ahhq.xn--p1ai",
      "server16.xn--j1ahhq.xn--p1ai",
      "server2.xn--j1ahhq.xn--p1ai",
      "server3.xn--j1ahhq.xn--p1ai",
      "server4.xn--j1ahhq.xn--p1ai",
      "server5.xn--j1ahhq.xn--p1ai",
      "server6.xn--j1ahhq.xn--p1ai",
      "server7.xn--j1ahhq.xn--p1ai",
      "server8.xn--j1ahhq.xn--p1ai",
      "server9.xn--j1ahhq.xn--p1ai",
      "xn--j1ahhq.xn--p1ai" 
    ],

Please see this test: https://github.com/OISF/suricata-verify/pull/1743/files#diff-1fe69d447a4f37103b703b8e6ef28039c0853a6120f7b962487ffef188722ab0R1

the cert referenced within the crt.sh link above is a good example.

I was wondering if this supported multi-buffer mode, or if they were concatenated together in some predictable format (http.header_names style), etc.

It is indeed supported in multi-buffer mode.
Please see this test for ref: https://github.com/OISF/suricata-verify/pull/1743/files#diff-7c7feedc3fa804dbd48367362fede7508f802e42fafe0f8cc69b7523fee22263R1

Please lmk if this makes sense to you or if something is not as per your expectations. Also, can I make the tests better?

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 #10

Updated by Shivani Bhardwaj 11 months ago

  • Status changed from In Review to Closed
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 #11

Updated by Victor Julien 16 days ago

  • Subject changed from SSL/TLS Sticky Buffer for subjectAltName to tls: subjectAltName buffer
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