Get Site's Certificates

Get-SiteCert.ps1

# Given a URI fetches the certificates hosted on that site, then parses the PEM to extract user friendly info (currently just as strings; I've not added logic to convert the output to PSCustomObjects, though may add that soon if I find the need).
$uri = 'example.org'
$output = (echo "" | openssl s_client -connect "$($uri):443" -servername $uri -showcerts 2>$null) -join "`n"
$output | select-string '(?smi)-----BEGIN CERTIFICATE-----(.*?)-----END CERTIFICATE-----' -AllMatches | %{$_.Matches} | %{$_.Value | openssl x509 -issuer -fingerprint -sha256 -enddate -subject -noout;'---'}

<# # Example Output #
issuer=C = US, O = DigiCert Inc, CN = DigiCert Global G3 TLS ECC SHA384 2020 CA1
SHA256 Fingerprint=85:A1:DF:2F:31:49:6B:1F:D7:04:A8:43:6D:30:9C:DC:5C:1B:4B:B3:95:6F:B3:1A:73:2A:C1:82:4D:AF:CA:C2
notAfter=Jan 15 23:59:59 2026 GMT
subject=C = US, ST = California, L = Los Angeles, O = Internet Corporation for Assigned Names and Numbers, CN = *.example.org
---
issuer=C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root G3
SHA256 Fingerprint=05:87:D6:BD:28:19:58:7A:B9:0F:B5:96:48:0A:57:93:BD:9F:75:06:A3:EA:CE:73:F5:EA:B3:66:01:7F:E2:59
notAfter=Apr 13 23:59:59 2031 GMT
subject=C = US, O = DigiCert Inc, CN = DigiCert Global G3 TLS ECC SHA384 2020 CA1
---
#>