[Linux][openssl] certificate.crt 인증 파일 정보 상세히 확인하기

아래 명령어를 사용하여 인증서 파일의 정보를 상세히 확인할 수 있다.

$ openssl x509 -text -noout < certificate.crt # 전체 정보 확인
$ openssl x509 -text -noout < certificate.crt | less # 내용이 길어 짤리는 경우 (F:다음, Q:종료)
$ openssl x509 -text -noout < certificate.crt | grep DNS # 도메인 정보만 확인
DNS:devjh.tk, DNS:www.devjh.tk # 결과

# 인증서 내용 발급 (인증서 발급처: ZeroSSL)
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            55:d8:42:f2:ed:5a:93:a8:fe:c6:f1:50:17:bd:89:06
        Signature Algorithm: sha384WithRSAEncryption # 서명 알고리즘 정보
        Issuer: C = AT, O = ZeroSSL, CN = ZeroSSL RSA Domain Secure Site CA
        Validity
            Not Before: Mar 28 00:00:00 2023 GMT
            Not After : Jun 26 23:59:59 2023 GMT # 만료시간
        Subject: CN = devjh.tk
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit) # RSA Key Bit
                Modulus:
                    00:c5:12:aa:dc:a9:c6:40:a0:76:48:fa:19:1b:62:
                    ea:c9:b6:de:7d:fb:32:43:c5:1b:ba:fb:56:60:22:
                    08:82:22:60:e6:db:5e:f7:66:bd:c1:17:a2:37:3f:
                    f3:33:99:4e:e4:6a:a1:83:0d:d3:8d:a9:5e:11:f6:
                    3b:bf:89:99:36:bf:4c:bb:9b:b5:47:9c:02:6c:aa:
                    7d:d9:4d:b1:c9:a8:4e:75:f5:86:34:f2:77:5c:40:
                    11:20:12:49:bb:82:6c:e9:29:4e:34:07:99:8a:10:
                    36:af:87:10:27:63:7b:05:8c:9b:54:d4:a6:e0:a6:
                    d7:54:f2:79:0c:e2:8d:7b:b8:b3:33:be:ff:c6:07:
                    c8:e8:2a:6b:80:81:1c:c6:a5:e5:c4:5e:e7:6d:4c:
                    01:40:33:64:df:b9:3e:a0:ab:ca:b4:88:43:7c:ef:
                    e3:de:08:53:a3:68:09:f9:b4:d5:e0:4f:92:0c:ad:
                    fb:1b:1c:1b:42:4f:16:e6:05:c5:c6:d0:9c:06:8d:
                    45:82:fc:e9:7f:6e:42:81:bf:26:6e:c8:01:85:b7:
                    d0:ab:37:5a:1e:b2:9b:ee:ec:6a:d2:eb:6e:81:62:
                    18:0d:4a:f5:d9:28:ce:1c:93:ee:b8:33:9a:dc:c8:
                    91:c6:ae:3e:f7:ed:96:8a:71:ef:e4:f0:c9:99:9b:
                    5e:23
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Authority Key Identifier:
                keyid:C8:D9:78:68:A2:D9:19:68:D5:3D:72:DE:5F:0A:3E:DC:B5:86:86:A6

            X509v3 Subject Key Identifier:
                FA:C7:19:CD:73:8F:6C:FE:AB:F7:92:FC:F2:89:95:D9:C4:E8:1D:69
            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment
            X509v3 Basic Constraints: critical
                CA:FALSE
            X509v3 Extended Key Usage:
                TLS Web Server Authentication, TLS Web Client Authentication
            X509v3 Certificate Policies:
                Policy: 1.3.6.1.4.1.6449.1.2.2.78
                  CPS: https://sectigo.com/CPS
                Policy: 2.23.140.1.2.1

            Authority Information Access: # 인증기관 정보
                CA Issuers - URI:http://zerossl.crt.sectigo.com/ZeroSSLRSADomainSecureSiteCA.crt
                OCSP - URI:http://zerossl.ocsp.sectigo.com

            CT Precertificate SCTs:
             Signed Certificate Timestamp:
                    Version   : v1 (0x0)
                    Log ID    : AD:F7:BE:FA:7C:FF:10:C8:8B:9D:3D:9C:1E:3E:18:6A:
                                B4:67:29:5D:CF:B1:0C:24:CA:85:86:34:EB:DC:82:8A
                    Timestamp : Mar 28 11:18:31.593 2023 GMT # 발급시간
                    Extensions: none
                    Signature : ecdsa-with-SHA256
                                30:45:02:20:4C:34:28:87:29:56:87:0B:D6:A6:19:41:
                                89:90:2E:B4:1E:B1:90:EB:6A:66:D9:C3:57:8F:3D:45:
                                DA:37:30:8E:02:21:00:F1:90:32:BE:EE:CA:C4:1F:04:
                                D1:D1:C1:21:F2:95:35:52:95:CD:05:47:99:A3:64:A4:
                                3E:EC:60:C4:CB:B0:DF
                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 : Mar 28 11:18:31.688 2023 GMT # 발급시간
                    Extensions: none
                    Signature : ecdsa-with-SHA256
                                30:44:02:20:1E:3B:32:9B:C1:F5:7E:F9:CA:34:53:93:
                                AD:8F:43:9D:3A:60:D7:2A:EC:3D:FF:A4:06:E6:6D:33:
                                90:EA:BB:83:02:20:29:7C:62:B8:7B:F6:74:32:6D:4E:
                                AA:41:0C:34:E2:36:A2:8F:6B:95:A3:87:9F:BC:01:10:
                                2E:AA:D5:E0:94:CD
            X509v3 Subject Alternative Name:
                DNS:devjh.tk, DNS:www.devjh.tk # SSL 도메인
    Signature Algorithm: sha384WithRSAEncryption # 서명 알고리즘 정보
         42:0d:2f:8b:8d:32:12:f0:cf:db:f5:93:c1:b6:14:b8:7d:c8:
         1b:b7:8f:81:77:86:40:d4:eb:62:c5:96:c5:2f:4d:be:8a:84:
         87:00:9b:ed:97:98:a0:f9:21:50:b4:e5:93:44:2f:05:04:de:
         30:8f:5e:73:ac:9a:9f:bd:fc:35:91:11:9e:5c:f1:ed:c3:74:
         c3:f6:1f:46:10:3a:e3:5b:8c:04:01:5c:da:80:ee:5d:37:a8:
         10:5f:3e:3e:89:77:ca:c1:4a:13:da:93:62:b8:e3:61:d3:10:
         c6:52:e4:f5:a5:07:99:cf:97:26:7e:6b:76:04:98:6a:85:76:
         15:c8:6a:dc:ca:2d:01:da:0c:c3:13:85:f0:b8:69:f5:75:0e:
         c1:6c:ab:b9:f7:17:6d:7d:a1:b7:fc:fb:32:85:38:93:51:cc:
         cf:dd:c1:a3:ab:b7:2e:70:ca:ee:8d:0f:50:fc:d1:0a:c3:2c:
         ba:e2:c7:b6:ed:7e:02:57:cc:6a:9c:61:a3:5e:b4:ae:5a:a1:
         f9:a8:d9:7d:4e:f8:87:de:7b:bd:72:e8:5c:04:fc:31:e3:a2:
         ab:9c:f7:3c:09:4c:59:fd:31:85:04:66:98:0e:27:73:a4:c7:
         42:41:f6:de:f3:54:6e:9b:6c:6c:f3:f6:ef:fc:e6:84:a3:19:
         3f:19:3b:6e:a1:9a:45:cf:0c:a0:ff:9b:8f:36:a4:56:89:a8:
         40:46:d5:04:b1:ce:18:6e:b9:a1:20:5e:2e:35:ab:fd:6b:6e:
         6f:73:fe:fd:08:48:a7:30:f6:2d:67:89:39:08:10:f6:ce:da:
         d6:a6:ee:4d:2e:92:f1:ca:88:46:19:70:fd:af:be:d1:47:ef:
         de:7b:c6:d1:2f:2f:e2:ac:ed:b6:3f:87:52:3c:52:10:59:25:
         0b:f1:50:48:57:a9:a6:54:9c:3e:bb:da:30:e7:93:9c:01:ad:
         d3:c2:63:9b:f1:03:85:c9:8f:d0:00:c8:c4:6d:0d:7e:12:b2:
         f1:f3:4d:9d:da:a6:7c:7e:64:33:f8:ef:2f:e4:90:6a:be:5f:
         be:00:cb:ba:68:db:c1:4c:78:80:90:b4:c2:53:47:0a:a6:95:
         0c:16:0e:e5:2d:e4:8b:47:9e:54:d3:db:b8:5a:b1:cf:b4:5f:
         68:df:62:85:77:a0:d9:63:27:c8:38:bf:32:5f:6d:5c:1f:f5:
         20:d8:17:10:cc:05:f6:1f:a2:92:05:5c:66:a9:06:4d:e5:c3:
         09:41:55:ba:0d:c8:a2:2d:88:a4:6f:5f:ee:8c:3b:4e:2d:80:
         00:17:2a:01:b2:2a:82:7b:c1:2f:fd:6e:c2:84:22:bf:d4:8e:
         b0:6c:f9:7a:26:0d:0d:52