"Seven Years in the Life of Hypergiants' Off-Nets"
ACM SIGCOMM 2021 Artifacts
Table of Contents
Getting Started
Prerequisites and Installation
The entire software was written in python3, which has to be pre-installed on your system.
Install pip3:
sudo apt-get install python3-pip
In order to isolate the following installation and runs from other parts of the system, we can run everything in a python3 venv environment. This can be done according to the instructions on the python3 venv tutorial.
Please, follow the aforementioned guide to set up an environment on your system.
Then, install the required python3 packages within the venv:
pip3 install -r requirements.txt
In case a required dependency is missing, please contact p.gkigkis at cs.ucl.ac.uk.
Getting Acccess to the Datasets
Our methodology uses TLS certificate scans as a building block, supplementing them with additional techniques (e.g., HTTP(S) fingerprints) and datasets (e.g., IP-to-AS mapping, APNIC user population estimates, etc..).
We document in detail the datasets here.
Results Overview
The Analysis step allows you to infer the off-nets per hypergiant by reproducing the methodology section of the paper.
Then, to explore the results we provide additional Meta-Analysis scripts.
Meta-Analysis Group Hypergiant validated off-nets by continent allows you to reproduce the results used in Figure 5.
Meta-Analysis Estimate Hypergiant country coverage allows you to reproduce the Internet user population coverage (percentage) per country for off-net footprints results used in Figures 6, 7 and 8.
Analysis
For the analysis part, we suggest to populate the datasets folder of this repository, following these instructions.
The next steps suffice to infer the off-nets of the considered Hypergiants in this study. We will include more analysis commands that are available in the software at a later stage.
Step 0:
cd analysis
Step 1: Extract End-Entity (EE) certificates.
As a first step, the script takes as an input the certificate dataset and extracts the End-Entity (EE) certificate of each IP. Expired, self-signed and root/intermediate certificates that are not present in the CCADB Common CA Database are filtered out.
Currently, as an input we support the following two datasets:
- Active Scan (Certigo) - Suggested
- Rapid7 TLS scans
To run the script, execute the following command:
python3 extract_valid_certs.py -d 21-11-2019 -t active -i ../datasets/tls_scans/active/
This will generate the folder active_21-11-2019 inside the analysis/results.
Inside the folder it will create a single JSON line-by-line file "ee_certs.txt". Each line contains a JSON object formatted as:
{ "ip" : "EndEntity-Certificate" }
Step 2: Find TLS fingerprints using hypergiant on-net certificates.
Script extract_hypergiant_on-net_certs.py takes as an input the generated file of step 1, the configuration file, the list of HG ASes and, the IP-to-AS mapping.
The configuration file contains a mapping between the candidate HG keyword and the HG ASes. Here is an example of a configuration file.
{"hypergiant-keyword" : "google", "hypergiant-ases-key" : "google"}
{"hypergiant-keyword" : "facebook", "hypergiant-ases-key" : "facebook"}
{"hypergiant-keyword" : "netflix", "hypergiant-ases-key" : "netflix"}
{"hypergiant-keyword" : "akamai", "hypergiant-ases-key" : "akamai"}
{"hypergiant-keyword" : "alibaba", "hypergiant-ases-key" : "alibaba"}
Any value can be used as a "hypergiant-keyword". For the "hypergiant-ases-key" we support the following values:
['yahoo', 'cdnetworks', 'limelight', 'microsoft', 'chinacache', 'apple', 'alibaba', 'amazon', 'akamai', 'bitgravity', 'cachefly', 'cloudflare', 'disney', 'facebook', 'google', 'highwinds', 'hulu', 'incapsula', 'netflix', 'cdn77', 'twitter', 'fastly']
To run the script, execute the following command:
python3 extract_hypergiant_on-net_certs.py -s ../datasets/hypergiants/2019_11_hypergiants_asns.json -i results/active_21-11-2019/ee_certs.txt -c configs/config.txt -a ../datasets/ip_to_as/2019_11_25thres_db.json
This will create a folder "on-nets" inside "analysis/results/active_21-11-2019/". The folder contains a file per HG keyword. Each file includes only the dns_names and subject:organization fields of the EE certificates found in IP addresses of the HG AS(es) using this specific keyword.
Here is an output example.
{"ip": "23.72.3.228", "ASN": 16625, "dns_names": ["try.akamai.com", "threatresearch.akamai.com"], "subject:organization": "akamai technologies, inc. "}
{"ip": "23.223.192.18", "ASN": 20940, "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. "}
{"ip": "172.232.1.72", "ASN": 20940, "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. "}
{"ip": "210.61.248.97", "ASN": 20940, "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. "}
Step 3: Find candidate hypergiant off-nets.
Script extract_hypergiant_off-net_certs.py takes as an input the generated file of step 1, the generated folder of step 2, the list of HG ASes and, the IP-to-AS mapping.
To run the script, execute the following command:
python3 extract_hypergiant_off-net_certs.py -s ../datasets/hypergiants/2019_11_hypergiants_asns.json -i results/active_21-11-2019/ee_certs.txt -c configs/config.txt -a ../datasets/ip_to_as/2019_11_25thres_db.json -o results/active_21-11-2019/on-nets
This will create a folder "candidate_off-nets" inside "analysis/results/active_21-11-2019/". The folder contains a file per HG keyword. Each file includes only the dns_names and subject:organization fields of the EE certificates found in IP addresses outside of the HG AS(es) using this specific keyword.
Here is an output example.
{"ip": "80.239.236.44", "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. ", "ASN": 1299}
{"ip": "2.18.52.28", "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. ", "ASN": 33905}
{"ip": "2.16.173.163", "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. ", "ASN": 20940}
{"ip": "77.94.66.28", "dns_names": ["a248.e.akamai.net", "*.akamaized-staging.net", "*.akamaized.net", "*.akamaihd-staging.net", "*.akamaihd.net"], "subject:organization": "akamai technologies, inc. ", "ASN": 60772}
Step 4: Parse HTTP and HTTPS headers.
Please, refer here on how to obtain the HTTP(S) header files. Due to the size of these files (~60GB compressed), we suggest to not completely uncompress them.
In our analysis, we always use the gunzip -kc flags to keep the files compressed, while sending the output to stdout.
Step 4.1 Find the HTTP(S) header names.
Execute the following command:
gunzip -kc ../datasets/headers/http/2019-11-18-1574121404-http_get_80.json.gz | ./parse_rapid7_headers.py | awk -F'\t' '{ if(NF == 2) print $0 }' | gzip > results/active_21-11-2019/header_names_2019-11-18-1574121404-http_get_80.json.gz
The output of the script is a tab separated line with <ip>\t<header-list>. Each header name and header value pair is separated by ":", and each header pair is separated by "|". The script contains a list of "uninteresting" headers which are ignored (e.g., "Server: Apache/PHP"). Finally, IP values without "interesting" headers or any headers at all, are output with an empty header-list, so we can keep track of IP addresses missing from the dataset.
Here is an output example.
104.24.40.135 Set-Cookie:__cfduid=d388387dd3c34cc6c4e37c62d3bc4beb91574121663; expires=Wed, 18-Nov-20 00:01:03 GMT; path=/; domain=.104.24.40.135; HttpOnly|Server:cloudflare|CF-RAY:537de84e0b49ed37-SJC
23.231.139.150
45.38.39.238
167.82.1.144 Server:Varnish|X-Served-By:cache-bur17520-BUR|Via:1.1 varnish
107.165.5.254 Upgrade:h2
104.25.187.85 Set-Cookie:__cfduid=d51c717c0d086ff466c032113ed7265601574121664; expires=Wed, 18-Nov-20 00:01:04 GMT; path=/; domain=.104.25.187.85; HttpOnly|Server:cloudflare|CF-RAY:537de8506816ed2f-SJC
23.57.49.186 Server:AkamaiGHost
Step 4.2 Apply the header rules in hypergiant-headers.txt to the file generated in step 4.1.
The map_networks.py script outputs a tab separated line of ip, hypergiant, header_match. IPs with no CDN header matches are also output to keep track of what IPs exist in the data.
Execute the following command:
gunzip -kc results/active_21-11-2019/header_names_2019-11-18-1574121404-http_get_80.json.gz | python3 ./map_hypergiants_headers.py | gzip > results/active_21-11-2019/mapped_header_names_headers_names_2019-11-18-1574121404-http_get_80.json.gz
Here is an output example.
104.24.40.135 Cloudflare server:cloudflare
104.25.187.85 Cloudflare server:cloudflare
23.57.49.186 Akamai server:akamaighost
104.18.84.77 Cloudflare server:cloudflare
104.144.176.112 Alibaba server:tengine/2.0.0
52.7.82.238 Amazon server:awselb/2.0
Note: For each snapshot you need to download only the corresponding HTTP and HTTPs header files with the alligned dates from Rapid7.
Step 5: Compare candidate off-nets with HTTP(S) fingerprints.
The find_offnets.py script takes as an input the candidate off-nets folder of Step 3, and the HTTP(S) header fingerprints of Step 4.
Execute the following command:
python3 find_offnets.py -o results/active_21-11-2019/candidate_off-nets/ -https results/active_21-11-2019/mapped_headers_names_https_2019-11-18-1574084778-https_get_443.json.gz -http results/active_21-11-2019/mapped_headers_names_2019-11-18-1574121404-http_get_80.json.gz
This will generate the folder "candidate-off-nets" inside the "analysis/results". The folder contains a file per HG with the off-net ASes and their corresponding IP addresses.
Here is the JSON format of each file:
{ "AS-1" : [ "IP-1", "IP-2" ], "AS-2" : [ "IP-3", "IP-4", "IP-5", "IP-6" ] }
Meta-Analysis
Exploring results
The explore_results.py script outputs the inferred off-nets per hypergiant at AS-level granularity. The script takes as input the result folder of the analysis part.
Execute the following command:
python3 explore_results.py -i ../analysis/results/active_21-11-2019/
Here is an output example.
HG Keyword: 'akamai'
Found Candidate Off-nets (only certificates) in 1228 ASes.
Found Off-nets (validated with HTTP(s) headers) in 1187 ASes.
-------------------------------------------------------------------
HG Keyword: 'disney'
Found Candidate Off-nets (only certificates) in 194 ASes.
Found Off-nets (validated with HTTP(s) headers) in 0 ASes.
-------------------------------------------------------------------
You can also get a list of the ASes per hypergiant, using the argument -p true, by executing the following command:
python3 explore_results.py -i ../analysis/results/active_21-11-2019/ -p true
Here is an output example.
HG Keyword: 'alibaba'
Found Candidate Off-nets (only certificates) in 300 ASes.
Found Off-nets (validated with HTTP(s) headers) in 154 ASes.
ASes for Candidate Off-nets:
AS136192, AS136193, AS4609, AS136195, AS6147, AS20485, AS45061, ...
- - -
ASes for Validated Off-nets:
AS577, AS17897, AS136188, AS9394, AS54994, AS131565, AS58519, AS134771, ...
-------------------------------------------------------------------
HG Keyword: 'disney'
Found Candidate Off-nets (only certificates) in 194 ASes.
Found Off-nets (validated with HTTP(s) headers) in 0 ASes.
ASes for Candidate Off-nets:
AS4609, AS6147, AS8708, AS55818, AS13335, AS15897, AS19994, ...
- - -
ASes for Validated Off-nets:
-------------------------------------------------------------------
Group Hypergiant validated off-nets by continent
The group_by_continent.py script takes as input the result folder of the analysis part (uses the validated off-nets) and the CAIDA AS-to-Organization info dataset. To obtain the latter dataset refer here.
Execute the following command:
python3 group_by_continent.py -i ../analysis/results/active_21-11-2019 -c ../datasets/organization_info/20191101.as-org2info.txt
The script creates results/active_21-11-2019/offnets_to_continents inside the meta-analysis folder. For each hypergiant it creates a text file formatted as follows:
Here is an output example for google.
EU: 793 ASes
AF: 166 ASes
SA: 874 ASes
AS: 778 ASes
NA: 403 ASes
OC: 51 ASes
# # #
EU: AS34058, AS41794, AS5550, AS34187, AS8218, ...
- - -
AF: AS10474, AS36992, AS24835, AS327818, AS37612, ...
- - -
SA: AS266445, AS23140, AS262676, AS262634, AS263244, ...
- - -
AS: AS133830, AS135772, AS15802, AS132735, AS45271, ...
- - -
NA: AS26133, AS600, AS53435, AS36728, AS19165, ...
- - -
OC: AS132797, AS18200, AS10131, AS9790, AS133612, ...
- - -
Estimate Hypergiant country coverage
The country_coverage.py script takes as input the result folder of the analysis part (uses the validated off-nets) and the APNIC user population per ASN estimates.
Execute the following command:
python3 country_coverage.py -i ../analysis/results/active_21-11-2019 -a ../datasets/apnic_population_estimates/2019_11.json
The script creates results/active_21-11-2019/country_coverage inside the meta-analysis folder. For each hypergiant it creates a text file formatted as follows:
Country-Alpha‑2-code,Coverage-Percentage
Here is an output example.
BD,82.89108306883769
BE,54.36254335595898
BF,86.31532375598584
BG,62.11203725552794
BA,80.72960244254675
BB,98.43826732090602