When viewing the certificate on the server side, you can import the server's public key certificate file, or directly crawl and view the certificate from the server.
The following common methods:
Method 1: Crawl and view the certificate directly from the server
Can be passedkeytoolTo connect to the remote server's port and view its SSL/TLS certificate:
keytool -printcert -rfc -sslserver <hostname>:<port>
-
<hostname>: The host name or IP address of the server. -
<port>: The server uses the SSL/TLS port number, usually 443 (HTTPS) or other ports.
Assume that you need to viewWebsite certificate:
keytool -printcert -rfc -sslserver :443
After running this command, you will see the server's certificate details, including all certificates in the certificate chain, issuer information, public key, validity period, etc.
Method 2: Crawl and view the certificate through openssl
If you don't want to usekeytool, can be usedopensslTool to grab the server-side certificate and then passkeytoolCheck:
1. Useopenssl Crawl the server certificate：
openssl s_client -connect <hostname>:<port> -showcerts
This outputs the server's certificate chain, including the server certificate and other certificates in the chain.
2. Save the certificate：
Save the certificate to a file (e.g.)middle.
3. Usekeytool View the certificate：
keytool -printcert -file
Method 3: Download and view the certificate file
Sometimes, the certificate file may have been downloaded from the server (e.g..ceror.crtFile), can be used directlykeytoolCheck:
keytool -printcert -file <cert-file-path> keytool -printcert -file
Certificate information analysis
In the output, you can see the following information:
- Owner: Certificate owner information (usually including CN, OU, O, L, ST, C, etc.).
- Issuer: Certificate issuer information.
- Serial number: The serial number of the certificate.
- Valid from / to: The validity period of the certificate.
-
Signature algorithm: Signature algorithm (such as
SHA256withRSA）。 - Public key: Details of the public key.
Through these methods, it is possible to easily view the server's certificate information and check whether the certificate is valid, or further used for operations such as trust chain verification.
Summarize
The above is personal experience. I hope you can give you a reference and I hope you can support me more.