If you want to display details of an SSL certificate that is returned by a website from the Linux commandline, you can use this command.
1. Install required packages
In order to use the command below, the “openssl” package is required. You can install this package with this command:
sudo dnf install openssl
Or with yum:
sudo yum install openssl
2. Execute command-line command.
Execute the following statement in the Linux terminal.
echo | openssl s_client -showcerts -servername lanedirt.tech -connect lanedirt.etch:443 2>/dev/null | openssl x509 -inform pem -noout -text
Replace “lanedirt.tech” with the website you would like to see the SSL cert information for.
This command establishes a TLS connection to the target website on port 443 using OpenSSL’s s_client, specifically requesting the server’s SSL certificates. After fetching the certificates, the command then extracts the main certificate from the stream and uses openssl x509 to display its detailed information in a human-readable format. The 2>/dev/null part ensures that any error messages from the process are discarded and not shown in the output.
The command above returns output like this, which includes information about the certificate itself, common names, expiration dates etc.
[user@linux01 public_html]$ echo | openssl s_client -showcerts -servername lanedirt.tech -connect lanedirt.tech:443 2>/dev/null | openssl x509 -inform pem -noout -text
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
03:3c:7d:89:aa:ca:3b:08:21:a7:40:56:a1:9c:f7:cb:2b:5e
Signature Algorithm: sha256WithRSAEncryption
Issuer: C = US, O = Let's Encrypt, CN = R3
Validity
Not Before: Sep 15 21:10:38 2023 GMT
Not After : Dec 14 21:10:37 2023 GMT
Subject: CN = lanedirt.tech
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:64:59:ac:66:39:5f:73:81:2d:67:6b:c5:be:a3:
31:57:9e:76:f7:25:87:1e:72:8a:17:6f:f1:90:88:
6f:20:63:78:45:2c:99:81:da:9c:e3:1a:ca:1d:71:
5d:1b:20:f6:32:b2:d1:72:e7:73:ef:1d:18:85:c6:
9c:87:97:b3:06
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Key Usage: critical
Digital Signature
X509v3 Extended Key Usage:
TLS Web Server Authentication, TLS Web Client Authentication
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Subject Key Identifier:
E0:5E:AB:ED:41:AD:9B:E1:87:23:34:81:0E:1D:B5:70:F3:9F:F2:63
X509v3 Authority Key Identifier:
keyid:14:2E:B3:17:B7:58:56:CB:AE:50:09:40:E6:1F:AF:9D:8B:14:C2:C6
Authority Information Access:
OCSP - URI:http://r3.o.lencr.org
CA Issuers - URI:http://r3.i.lencr.org/
X509v3 Subject Alternative Name:
DNS:lanedirt.tech, DNS:www.lanedirt.tech
X509v3 Certificate Policies:
Policy: 2.23.140.1.2.1
CT Precertificate SCTs:
Signed Certificate Timestamp:
Version : v1 (0x0)
Log ID : 7A:32:8C:54:D8:B7:2D:B6:20:EA:38:E0:52:1E:E9:84:
16:70:32:13:85:4D:3B:D2:2B:C1:3A:57:A3:52:EB:52
Timestamp : Sep 15 22:10:38.789 2023 GMT
Extensions: none
Signature : ecdsa-with-SHA256
30:44:02:20:38:78:FB:74:F5:EA:21:46:D6:62:86:22:
52:35:04:72:31:D8:91:59:30:2C:9A:8B:18:10:CA:1D:
05:68:73:F8:02:20:35:75:08:D1:04:44:BC:EB:E3:3C:
89:42:73:A8:A4:35:E7:8D:97:98:F5:C5:E0:3F:34:89:
10:05:93:33:17:C8
Signed Certificate Timestamp:
Version : v1 (0x0)
Log ID : E8:3E:D0:DA:3E:F5:06:35:32:E7:57:28:BC:89:6B:C9:
03:D3:CB:D1:11:6B:EC:EB:69:E1:77:7D:6D:06:BD:6E
Timestamp : Sep 15 22:10:38.804 2023 GMT
Extensions: none
Signature : ecdsa-with-SHA256
30:45:02:21:00:BB:1D:D1:B2:A7:B7:BA:A5:31:C4:B7:
CB:6C:0B:8F:A1:90:BB:4E:CA:B2:E9:13:75:40:27:4D:
4B:14:B8:D3:F0:02:20:58:31:08:AA:9A:3C:3E:F7:F8:
11:04:6A:C3:CD:47:BC:3E:B7:35:0D:87:B6:D2:97:6D:
69:50:C4:94:F2:7B:03
Signature Algorithm: sha256WithRSAEncryption
82:0d:19:5b:38:90:ac:04:23:65:5a:53:38:87:f2:da:6d:95:
77:43:ed:8e:8d:18:91:92:7c:55:5b:a9:db:9d:be:aa:ad:6b:
6d:4f:d4:77:33:0e:aa:51:f4:e1:e2:77:9a:85:14:e6:6a:5e:
27:ef:4a:34:c8:73:c8:7e:b4:93:23:32:f0:4e:8d:68:d1:f0:
4e:f4:f5:39:5f:72:53:f9:17:0b:b8:c6:fe:56:3d:72:e0:88:
66:65:47:35:f4:fe:2c:ff:dc:a0:3b:97:2c:01:30:1c:4a:1e:
1f:6a:95:1b:c3:de:40:20:87:f6:25:c9:02:ba:50:0c:63:90:
3f:86:5e:7b:e6:d6:53:bd:c4:1f:c9:db:26:e1:48:63:f8:f0:
59:80:c7:5e:d7:de:a1:79:cf:6a:7a:29:ff:b2:ef:bd:b5:20:
73:83:b1:c0:47:16:72:ac:19:d2:86:f5:36:ed:be:f2:8f:d5:
d2:a2:a9:39:62:6b:01:ff:f7:67:d8:78:a3:17:fe:ff:00:b1:
18:a5:b8:ee:78:b7:3a:fc:c5:f1:95:4b:49:07:dd:d1:ea:f4:
64:e9:19:04:f2:f4:62:a0:17:0b:59:9e:bb:7a:27:df:ac:33:
22:83:59:94:6a:34:fe:bb:0a:d2:72:ff:7f:e0:86:31:1f:42:
e5:08:85:cb
