show.certificate.info

sudo openssl x509 -in /etc/letsencrypt/archive/example.com/fullchain2.pem -text -noout

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            f3:64:4e:6b:6e:00:50:23:7e:09:46:bd:7b:e1:f5:1d
        Signature Algorithm: ecdsa-with-SHA384
        Issuer: C=US, ST=New Jersey, L=Jersey City, O=The USERTRUST Network, CN=USERTrust ECC Certification Authority
        Validity
            Not Before: Nov  2 00:00:00 2018 GMT
            Not After : Dec 31 23:59:59 2030 GMT
        Subject: C=GB, ST=Greater Manchester, L=Salford, O=Sectigo Limited, CN=Sectigo ECC Domain Validation Secure Server CA
        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (256 bit)
                pub:
                    04:79:18:93:ca:9f:6d:9e:6c:57:00:23:05:37:0b:
                    5f:0f:58:5a:c4:de:7f:55:a3:e9:1e:d6:d9:25:0a:
                    88:a0:20:4a:1d:7a:4f:05:30:8a:63:49:13:8c:64:
                    21:07:95:fd:3a:35:e1:4a:ce:90:f0:18:f7:3d:af:
                    68:a6:fb:d4:48
                ASN1 OID: prime256v1
                NIST CURVE: P-256
        X509v3 extensions:
            X509v3 Authority Key Identifier:
                3A:E1:09:86:D4:CF:19:C2:96:76:74:49:76:DC:E0:35:C6:63:63:9A
            X509v3 Subject Key Identifier:
                F6:85:0A:3B:11:86:E1:04:7D:0E:AA:0B:2C:D2:EE:CC:64:7B:7B:AE
            X509v3 Key Usage: critical
                Digital Signature, Certificate Sign, CRL Sign
            X509v3 Basic Constraints: critical
                CA:TRUE, pathlen:0
            X509v3 Extended Key Usage:
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Certificate Policies:
                Policy: X509v3 Any Policy
                Policy: 2.23.140.1.2.1
            X509v3 CRL Distribution Points:
                Full Name:
                  URI:http://crl.usertrust.com/USERTrustECCCertificationAuthority.crl
            Authority Information Access:
                CA Issuers - URI:http://crt.usertrust.com/USERTrustECCAddTrustCA.crt
                OCSP - URI:http://ocsp.usertrust.com
    Signature Algorithm: ecdsa-with-SHA384
    Signature Value:
        30:65:02:30:4b:e7:c7:71:5c:b1:5c:09:6d:9a:42:60:5f:73:
        e9:f0:d6:26:d4:b5:51:54:6c:71:2d:1c:85:60:4d:28:f1:4d:
        a6:f0:ca:76:b7:4a:45:ef:a8:02:4a:f6:8d:4f:ae:6e:02:31:
        00:e0:e1:79:2a:f6:5e:17:00:ee:8c:fd:1e:67:9d:19:d3:21:
        96:b7:7d:e1:3a:0a:15:b6:65:fb:f3:a7:14:5c:ea:9e:f3:a1:
        72:31:ef:0a:51:02:11:07:0a:99:cf:1f:98