A next-generation crawling and spidering framework

Features • Installation • Usage • Scope • Config • Filters • Join Discord

Features

• Fast And fully configurable web crawling
• Standard and Headless mode support
• JavaScript parsing / crawling
• Customizable automatic form filling
• Scope control – Preconfigured field / Regex
• Customizable output – Preconfigured fields
• INPUT – STDIN, URL and LIST
• OUTPUT – STDOUT, FILE and JSON

Installation

katana requires Go 1.18 to install successfully. To install, just run the below command or download pre-compiled binary from release page.

go install github.com/projectdiscovery/katana/cmd/katana@latest

Usage

katana -h

This will display help for the tool. Here are all the switches it supports.

Running Katana

Input for katana

katana requires url or endpoint to crawl and accepts single or multiple inputs.

Input URL can be provided using -u option, and multiple values can be provided using comma-separated input, similarly file input is supported using -list option and additionally piped input (stdin) is also supported.

URL Input

katana -u https://tesla.com

Multiple URL Input (comma-separated)

katana -u https://tesla.com,https://google.com

List Input

$ cat url_list.txt

https://tesla.com
https://google.com

katana -list url_list.txt

STDIN (piped) Input

echo https://tesla.com | katana

cat domains | httpx | katana

Example running katana –

katana -u https://youtube.com

   __        __                
  / /_____ _/ /____ ____  ___ _
 /  '_/ _  / __/ _  / _ \/ _  /
/_/\_\\_,_/\__/\_,_/_//_/\_,_/ v0.0.1                     

      projectdiscovery.io

[WRN] Use with caution. You are responsible for your actions.
[WRN] Developers assume no liability and are not responsible for any misuse or damage.
https://www.youtube.com/
https://www.youtube.com/about/
https://www.youtube.com/about/press/
https://www.youtube.com/about/copyright/
https://www.youtube.com/t/contact_us/
https://www.youtube.com/creators/
https://www.youtube.com/ads/
https://www.youtube.com/t/terms
https://www.youtube.com/t/privacy
https://www.youtube.com/about/policies/
https://www.youtube.com/howyoutubeworks?utm_campaign=ytgen&utm_source=ythp&utm_medium=LeftNav&utm_content=txt&u=https%3A%2F%2Fwww.youtube.com   %2Fhowyoutubeworks%3Futm_source%3Dythp%26utm_medium%3DLeftNav%26utm_campaign%3Dytgen
https://www.youtube.com/new
https://m.youtube.com/
https://www.youtube.com/s/desktop/4965577f/jsbin/desktop_polymer.vflset/desktop_polymer.js
https://www.youtube.com/s/desktop/4965577f/cssbin/www-main-desktop-home-page-skeleton.css
https://www.youtube.com/s/desktop/4965577f/cssbin/www-onepick.css
https://www.youtube.com/s/_/ytmainappweb/_/ss/k=ytmainappweb.kevlar_base.0Zo5FUcPkCg.L.B1.O/am=gAE/d=0/rs=AGKMywG5nh5Qp-BGPbOaI1evhF5BVGRZGA
https://www.youtube.com/opensearch?locale=en_GB
https://www.youtube.com/manifest.webmanifest
https://www.youtube.com/s/desktop/4965577f/cssbin/www-main-desktop-watch-page-skeleton.css
https://www.youtube.com/s/desktop/4965577f/jsbin/web-animations-next-lite.min.vflset/web-animations-next-lite.min.js
https://www.youtube.com/s/desktop/4965577f/jsbin/custom-elements-es5-adapter.vflset/custom-elements-es5-adapter.js
https://w   ww.youtube.com/s/desktop/4965577f/jsbin/webcomponents-sd.vflset/webcomponents-sd.js
https://www.youtube.com/s/desktop/4965577f/jsbin/intersection-observer.min.vflset/intersection-observer.min.js
https://www.youtube.com/s/desktop/4965577f/jsbin/scheduler.vflset/scheduler.js
https://www.youtube.com/s/desktop/4965577f/jsbin/www-i18n-constants-en_GB.vflset/www-i18n-constants.js
https://www.youtube.com/s/desktop/4965577f/jsbin/www-tampering.vflset/www-tampering.js
https://www.youtube.com/s/desktop/4965577f/jsbin/spf.vflset/spf.js
https://www.youtube.com/s/desktop/4965577f/jsbin/network.vflset/network.js
https://www.youtube.com/howyoutubeworks/
https://www.youtube.com/trends/
https://www.youtube.com/jobs/
https://www.youtube.com/kids/

Crawling Mode

Standard Mode

Standard crawling modality uses the standard go http library under the hood to handle HTTP requests/responses. This modality is much faster as it doesn’t have the browser overhead. Still, it analyzes HTTP responses body as is, without any javascript or DOM rendering, potentially missing post-dom-rendered endpoints or asynchronous endpoint calls that might happen in complex web applications depending, for example, on browser-specific events.

Headless Mode

Headless mode hooks internal headless calls to handle HTTP requests/responses directly within the browser context. This offers two advantages:

• The HTTP fingerprint (TLS and user agent) fully identify the client as a legitimate browser
• Better coverage since the endpoints are discovered analyzing the standard raw response, as in the previous modality, and also the browser-rendered one with javascript enabled.

Headless crawling is optional and can be enabled using -headless option.

Here are other headless CLI options –

katana -h headless

Flags:
HEADLESS:
   -hl, -headless       enable experimental headless hybrid crawling
   -sc, -system-chrome  use local installed chrome browser instead of katana installed
   -sb, -show-browser   show the browser on the screen with headless mode
   -ho, -headless-options string[]  start headless chrome with additional options
   -nos, -no-sandbox                start headless chrome in --no-sandbox mode
   -noi, -no-incognito              start headless chrome without incognito mode

-no-sandbox

Runs headless chrome browser with no-sandbox option, useful when running as root user.

katana -u https://tesla.com -headless -no-sandbox

-no-incognito

Runs headless chrome browser without incognito mode, useful when using the local browser.

katana -u https://tesla.com -headless -no-incognito

-headless-options

When crawling in headless mode, additional chrome options can be specified using -headless-options, for example –

katana -u https://tesla.com -headless -system-chrome -headless-options --disable-gpu,proxy-server=http://127.0.0.1:8080

Scope Control

Crawling can be endless if not scoped, as such katana comes with multiple support to define the crawl scope.

-field-scope

Most handy option to define scope with predefined field name, rdn being default option for field scope.

• rdn – crawling scoped to root domain name and all subdomains (e.g. *example.com) (default)
• fqdn – crawling scoped to given sub(domain) (e.g. www.example.com or api.example.com)
• dn – crawling scoped to domain name keyword (e.g. example)

katana -u https://tesla.com -fs dn

-crawl-scope

For advanced scope control, -cs option can be used that comes with regex support.

katana -u https://tesla.com -cs login

For multiple in scope rules, file input with multiline string / regex can be passed.

$ cat in_scope.txt

login/
admin/
app/
wordpress/

katana -u https://tesla.com -cs in_scope.txt

-crawl-out-scope

For defining what not to crawl, -cos option can be used and also support regex input.

katana -u https://tesla.com -cos logout

For multiple out of scope rules, file input with multiline string / regex can be passed.

$ cat out_of_scope.txt

/logout
/log_out

katana -u https://tesla.com -cos out_of_scope.txt

-no-scope

Katana is default to scope *.domain, to disable this -ns option can be used and also to crawl the internet.

katana -u https://tesla.com -ns

-display-out-scope

As default, when scope option is used, it also applies for the links to display as output, as such external URLs are default to exclude and to overwrite this behavior, -do option can be used to display all the external URLs that exist in targets scoped URL / Endpoint.

katana -u https://tesla.com -do

Here is all the CLI options for the scope control –

katana -h scope

Flags:
SCOPE:
   -cs, -crawl-scope string[]       in scope url regex to be followed by crawler
   -cos, -crawl-out-scope string[]  out of scope url regex to be excluded by crawler
   -fs, -field-scope string         pre-defined scope field (dn,rdn,fqdn) (default "rdn")
   -ns, -no-scope                   disables host based default scope
   -do, -display-out-scope          display external endpoint from scoped crawling

Crawler Configuration

Katana comes with multiple options to configure and control the crawl as the way we want.

-depth

Option to define the depth to follow the urls for crawling, the more depth the more number of endpoint being crawled + time for crawl.

katana -u https://tesla.com -d 5

-js-crawl

Option to enable JavaScript file parsing + crawling the endpoints discovered in JavaScript files, disabled as default.

katana -u https://tesla.com -jc

-crawl-duration

Option to predefined crawl duration, disabled as default.

katana -u https://tesla.com -ct 2

-known-files

Option to enable crawling robots.txt and sitemap.xml file, disabled as default.

katana -u https://tesla.com -kf robotstxt,sitemapxml

-automatic-form-fill

Option to enable automatic form filling for known / unknown fields, known field values can be customized as needed by updating form config file at $HOME/.config/katana/form-config.yaml.

Automatic form filling is experimental feature.

   -aff, -automatic-form-fill  enable optional automatic form filling (experimental)

There are more options to configure when needed, here is all the config related CLI options –

katana -h config

Flags:
CONFIGURATION:
   -d, -depth int                maximum depth to crawl (default 2)
   -jc, -js-crawl                enable endpoint parsing / crawling in javascript file
   -ct, -crawl-duration int      maximum duration to crawl the target for
   -kf, -known-files string      enable crawling of known files (all,robotstxt,sitemapxml)
   -mrs, -max-response-size int  maximum response size to read (default 2097152)
   -timeout int                  time to wait for request in seconds (default 10)
   -retry int                    number of times to retry the request (default 1)
   -proxy string                 http/socks5 proxy to use
   -H, -headers string[]         custom header/cookie to include in request
   -config string                path to the katana configuration file
   -fc, -form-config string      path    to custom form configuration file

Filters

-field

Katana comes with built in fields that can be used to filter the output for the desired information, -f option can be used to specify any of the available fields.

   -f, -field string  field to display in output (url,path,fqdn,rdn,rurl,qurl,qpath,file,key,value,kv,dir,udir)

Here is a table with examples of each field and expected output when used –

Here is an example of using field option to only display all the urls with query parameter in it –

katana -u https://tesla.com -f qurl -silent

https://shop.tesla.com/en_au?redirect=no
https://shop.tesla.com/en_nz?redirect=no
https://shop.tesla.com/product/men_s-raven-lightweight-zip-up-bomber-jacket?sku=1740250-00-A
https://shop.tesla.com/product/tesla-shop-gift-card?sku=1767247-00-A
https://shop.tesla.com/product/men_s-chill-crew-neck-sweatshirt?sku=1740176-00-A
https://www.tesla.com/about?redirect=no
https://www.tesla.com/about/legal?redirect=no
https://www.tesla.com/findus/list?redirect=no

Custom Fields

You can create custom fields to extract and store specific information from page responses using regex rules. These custom fields are defined using a YAML config file and are loaded from the default location at $HOME/.config/katana/field-config.yaml. Alternatively, you can use the -flc option to load a custom field config file from a different location. Here is example custom field.

- name: email
  type: regex
  regex:
  - '([a-zA-Z0-9._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9_-]+)'
  - '([a-zA-Z0-9+._-]+@[a-zA-Z0-9._-]+\.[a-zA-Z0-9_-]+)'

- name: phone
  type: regex
  regex:
  - '\d{3}-\d{8}|\d{4}-\d{7}'

When defining custom fields, following attributes are supported:

• name (required)

The value of name attribute is used as the -field cli option value.

• type (required)

The type of custom attribute, currenly supported option – regex

• part (optional)

The part of the response to extract the information from. The default value is response, which includes both the header and body. Other possible values are header and body.

• group (optional)

You can use this attribute to select a specific matched group in regex, for example: group: 1

Running katana using custom field:

katana -u https://tesla.com -f email,phone

-store-field

To compliment field option which is useful to filter output at run time, there is -sf, -store-fields option which works exactly like field option except instead of filtering, it stores all the information on the disk under katana_field directory sorted by target url.

katana -u https://tesla.com -sf key,fqdn,qurl -silent

$ ls katana_field/

https_www.tesla.com_fqdn.txt
https_www.tesla.com_key.txt
https_www.tesla.com_qurl.txt

The -store-field option can be useful for collecting information to build a targeted wordlist for various purposes, including but not limited to:

• Identifying the most commonly used parameters
• Discovering frequently used paths
• Finding commonly used files
• Identifying related or unknown subdomains

-extension-match

Crawl output can be easily matched for specific extension using -em option to ensure to display only output containing given extension.

katana -u https://tesla.com -silent -em js,jsp,json

-extension-filter

Crawl output can be easily filtered for specific extension using -ef option which ensure to remove all the urls containing given extension.

katana -u https://tesla.com -silent -ef css,txt,md

Here are additional filter options –

   -f, -field string                field to display in output (url,path,fqdn,rdn,rurl,qurl,file,key,value,kv,dir,udir)
   -sf, -store-field string         field to store in per-host output (url,path,fqdn,rdn,rurl,qurl,file,key,value,kv,dir,udir)
   -em, -extension-match string[]   match output for given extension (eg, -em php,html,js)
   -ef, -extension-filter string[]  filter output for given extension (eg, -ef png,css)

Rate Limit

It’s easy to get blocked / banned while crawling if not following target websites limits, katana comes with multiple option to tune the crawl to go as fast / slow we want.

-delay

option to introduce a delay in seconds between each new request katana makes while crawling, disabled as default.

katana -u https://tesla.com -delay 20

-concurrency

option to control the number of urls per target to fetch at the same time.

katana -u https://tesla.com -c 20

-parallelism

option to define number of target to process at same time from list input.

katana -u https://tesla.com -p 20

-rate-limit

option to use to define max number of request can go out per second.

katana -u https://tesla.com -rl 100

-rate-limit-minute

option to use to define max number of request can go out per minute.

katana -u https://tesla.com -rlm 500

Here is all long / short CLI options for rate limit control –

katana -h rate-limit

Flags:
RATE-LIMIT:
   -c, -concurrency int          number of concurrent fetchers to use (default 10)
   -p, -parallelism int          number of concurrent inputs to process (default 10)
   -rd, -delay int               request delay between each request in seconds
   -rl, -rate-limit int          maximum requests to send per second (default 150)
   -rlm, -rate-limit-minute int  maximum number of requests to send per minute

Output

Katana support both file output in plain text format as well as JSON which includes additional information like, source, tag, and attribute name to co-related the discovered endpoint.

-output

By default, katana outputs the crawled endpoints in plain text format. The results can be written to a file by using the -output option.

katana -u https://example.com -no-scope -output example_endpoints.txt

-json

katana -u https://example.com -json -do | jq .

{
  "timestamp": "2022-11-05T22:33:27.745815+05:30",
  "endpoint": "https://www.iana.org/domains/example",
  "source": "https://example.com",
  "tag": "a",
  "attribute": "href"
}

-store-response

The -store-response option allows for writing all crawled endpoint requests and responses to a text file. When this option is used, text files including the request and response will be written to the katana_response directory. If you would like to specify a custom directory, you can use the -store-response-dir option.

katana -u https://example.com -no-scope -store-response

$ cat katana_response/index.txt

katana_response/example.com/327c3fda87ce286848a574982ddd0b7c7487f816.txt https://example.com (200 OK)
katana_response/www.iana.org/bfc096e6dd93b993ca8918bf4c08fdc707a70723.txt http://www.iana.org/domains/reserved (200 OK)

Note:

-store-response option is not supported in -headless mode.

Here are additional CLI options related to output –

katana -h output

OUTPUT:
   -o, -output string                file to write output to
   -sr, -store-response              store http requests/responses
   -srd, -store-response-dir string  store http requests/responses to custom directory
   -j, -json                         write output in JSONL(ines) format
   -nc, -no-color                    disable output content coloring (ANSI escape codes)
   -silent                           display output only
   -v, -verbose                      display verbose output
   -version                          display project version