Invoke-CRTRequest
Queries the certificate transparency website https://crt.sh with the provided domain and returns the results.
Invoke-CRTRequest [-Domain] <String> [-Deduplicate] [-ExcludeExpired] [[-Delay] <Int32>] [[-Retry] <Int32>] [-WhatIf] [-Confirm] [<CommonParameters>]
Certificates are deposited in public, transparent logs. Certificate logs are append-only ledgers of certificates. Because they're distributed and independent, anyone can query them to see what certificates have been included and when. Because they're append-only, they are verifiable by Monitors. Organisations and individuals with the technical skills and capacity can run a log.
This function queries the public logs using the web front end located at https://crt.sh
By default, the function performs no deduplication and includes all entries, even those that are expired. It also has a default sleep of 5 seconds when a web error occurs and it must retry a query. These options can be changed using parameters.
Output is an array of strings with various data embedded.
The following section shows the format in which https://crt.sh returns results as JSON.
[
{
"issuer_ca_id": 16418,
"issuer_name": "C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3",
"common_name": "icheck.lbapps.com",
"name_value": "icheck.lbapps.com",
"id": 3616206571,
"entry_timestamp": "2020-11-07T16:46:43.456",
"not_before": "2020-11-07T15:46:43",
"not_after": "2021-02-05T15:46:43",
"serial_number": "03ffeea57322e24cd6fd207682f59ead324f"
},
{
"issuer_ca_id": 13,
"issuer_name": "C=ZA, ST=Western Cape, L=Cape Town, O=Thawte Consulting cc, OU=Certification Services Division, CN=Thawte Premium Server CA, emailAddress=premium-server@thawte.com",
"common_name": "icheck.lbapps.com",
"name_value": "icheck.lbapps.com",
"id": 1451857,
"entry_timestamp": "2013-04-23T11:19:42.045",
"not_before": "2008-09-03T00:00:00",
"not_after": "2011-10-28T23:59:59",
"serial_number": "62d0a79bc5b32f9953489598013637d6"
}
]
You can use companion function Format-CRTResponse to perform some post-processing which converts all the multi-line strings into single-line strings and parses the embedded fields from the issuer_name field out into individual fields.
-Domain <String>
A single domain without an protocol, for example localhost.localdomain
Required? true
Position? 1
Default value localhost.localdomain
Accept pipeline input? false
Accept wildcard characters? false
-Deduplicate [<SwitchParameter>]
Deduplicate (pre)certificate pairs? The default setting is 'No'
Required? false
Position? named
Default value False
Accept pipeline input? false
Accept wildcard characters? false
-ExcludeExpired [<SwitchParameter>]
Exclude expired certificates? The default setting is 'No'
Required? false
Position? named
Default value False
Accept pipeline input? false
Accept wildcard characters? false
-Delay <Int32>
When a request fails, the function will sleep for this number of seconds before trying again. It will keep retrying until a success occurs. The default value is '5' seconds.
Required? false
Position? 2
Default value 5
Accept pipeline input? false
Accept wildcard characters? false
-Retry <Int32>
When a request fails, the function will retry the request. This parameter sets how many times it will retry the same request before moving on. The default is '-1' which will keep trying until there is a success.
Required? false
Position? 3
Default value -1
Accept pipeline input? false
Accept wildcard characters? false
-WhatIf [<SwitchParameter>]
Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false
-Confirm [<SwitchParameter>]
Required? false
Position? named
Default value
Accept pipeline input? false
Accept wildcard characters? false
<CommonParameters>
This cmdlet supports the common parameters: Verbose, Debug, ErrorAction, ErrorVariable, WarningAction, WarningVariable, OutBuffer, PipelineVariable, and OutVariable. For more information, see about_CommonParameters (https://go.microsoft.com/fwlink/?LinkID=113216).
Written by Word Eater (WordEaterNG@gmail.com)
Tested on Windows Server and Linux
Certificate Transparency Search Page - https://crt.sh/ How Certificate Transparency Works - https://certificate.transparency.dev/howctworks/
Used to convert a string into an array https://stackoverflow.com/questions/15927291/how-to-split-a-string-by-comma-ignoring-comma-in-double-quotes
Version History
v2.0-20230306 Moved post-processing to its own function called Format-CRTResponse
v1.6-20230111 Changed most Write-Host to Write-Verbose to be more like standard cmdlets
Changed Write-Host for the host not found to be a Write-Error
v1.5-20221227 Changed Deduplicate and ExcludeExpired to switch instead of boolean to be more like standard cmdlets
Changed Write-Output in End { } into a return
Moved return from End { } to the Proceess { } loop so it should be able to return partial values if something goes wrong
Added Write-Warning to non-terminating error messages
https://github.com/wordeater/Invoke-CRTRequest
https://github.com/wordeater/Format-CRTResponse