Differences

This shows you the differences between two versions of the page.

--- wiki:openssl_commands [2022/10/19 12:31] – [Query site for expiration date] fix whitespace and newline antisa
+++ wiki:openssl_commands [2024/06/12 12:21] (current) – [References] add using-openssl-to-get-the-certificate-from-a-server antisa
@@ Line 35: / Line 35: @@
 ===== Get cert file from site =====
-  openssl s_client -connect example.com:443 -servername example.com:443 < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > public.crt
+  openssl s_client -connect example.com:443 -servername example.com < /dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | openssl x509 -text -noout
+<WRAP center round info 60%>
+-connect can be the IP address of a server and is not necessarily the same as the -servername. Use -servername when sharing multiple SSL hosts on a single IP address,
+</WRAP>
 ===== Get OCSP stapling info =====
@@ Line 54: / Line 58: @@
 You need to get the same sha sum from both commands.
+===== Additional commands that can be used to inspect Certificates =====
+The openssl x509 utility also allows you to extract specific pieces of information from the certificate file instead of the entire content of a certificate in text.
+  openssl x509 -in google.com-cert -noout -serial
+  openssl x509 -in google.com-cert -noout -issuer
+  openssl x509 -in google.com-cert -noout -dates
+  openssl x509 -in google.com-cert -noout -subject
+  openssl x509 -in google.com-cert -noout -pubkey
+  openssl x509 -in google.com-cert -noout -modulus
+  openssl x509 -in google.com-cert -noout -ocsp_uri
+Note: Last command may not work in all versions of OpenSSL
+You can also mix and match arguments from the last step:
+  openssl x509 -in google.com-cert -noout -subject -issuer
+  openssl x509 -in google.com-cert -noout -serial -dates
+You can also request specific extensions from the certificate:
+  openssl x509 -in google.com-cert -noout -ext subjectAltName
+  openssl x509 -in google.com-cert -noout -ext basicConstraints
+  openssl x509 -in google.com-cert -noout -ext crlDistributionPoints
+  openssl x509 -in google.com-cert -noout -ext keyUsage
+  openssl x509 -in google.com-cert -noout -ext extendedKeyUsage
+  openssl x509 -in google.com-cert -noout -ext authorityInfoAccess
+  openssl x509 -in google.com-cert -noout -ext subjectKeyIdentifier
+  openssl x509 -in google.com-cert -noout -ext authorityKeyIdentifier
+====== See also ======
+  * [[wiki:creating_ca_and_signing_server_and_client_certs_with_openssl|Creating CA and signing server and client certs with openssl]]
 ====== References ======
   * https://www.xolphin.com/support/OpenSSL/Frequently_used_OpenSSL_Commands
   * https://www.namecheap.com/support/knowledgebase/article.aspx/9781/2238/nginx-ssl-error0b080074x509-certificate-routines-x509checkprivatekeykey-values-mismatch
+  * https://stackoverflow.com/questions/7885785/using-openssl-to-get-the-certificate-from-a-server