SSL証明書の情報確認方法について - とあるサーバエンジニアの備忘録

Webサイトの暗号化通信はもちろんMailサーバの暗号化通信などSSL通信が用いられているところが日々増えております。
もちろんSSL通信を行うためにはSSL証明書が必ず必要となってきます。

正規のSSL証明書はSSLストアさんなどで購入できます。
但しテスト用途などで暗号化ができればいいんだと言う方は、オレオレ証明書作成方法などを参考に
その他にも現在、Let's Encryptといって無料のSSL証明書を取得できる方法もありますので利用用途に応じてどのSSL証明書を使用するか検討頂ければと思います。

さて、今回はそんなSSL証明書に記載されている情報を確認する方法をご紹介します。

openssl x509 -noout -text -in {SSL証明書のファイルパス}

1 2	openssl x509 -noout -text -in {SSL証明書のファイルパス}

▼ちなみに当サイトで使用しているSSL証明書の情報を確認するとこんな感じでした

Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            db:47:bd:d1:2e:a1:e6:33:3f:b2:e9:d4:75:82:44:37
    Signature Algorithm: sha256WithRSAEncryption
        Issuer: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA
        Validity
            Not Before: Jun 14 00:00:00 2016 GMT
            Not After : Jun 14 23:59:59 2017 GMT
        Subject: OU=Domain Control Validated, OU=PositiveSSL, CN=aftercore.net
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (2048 bit)
                Modulus:
                    00:c8:76:58:2f:3a:a6:d0:b5:7d:b7:fb:09:e3:94:
                    fa:f5:98:0b:23:58:d3:26:d9:93:8a:5d:a3:06:ee:
                    83:e1:1d:a8:ce:34:88:5c:e9:c3:68:48:44:8b:0b:
                    d0:f4:bc:07:b3:81:15:82:d1:90:23:c5:84:93:be:
                    8a:58:33:84:41:08:76:47:64:f8:d0:3e:ba:73:eb:
                    90:23:bd:98:19:b2:7a:95:69:a5:b4:f7:a2:fe:f4:
                    62:16:55:e1:fc:ee:4a:82:97:3c:25:c2:d4:a1:ed:
                    d5:21:4b:7c:c0:64:61:05:72:cc:7a:4d:89:a8:14:
                    88:c7:64:fc:5d:b3:72:b0:34:26:67:2f:d3:ac:18:
                    a4:af:5f:a6:d1:76:72:01:92:d3:8e:cd:35:cf:82:
                    e3:7a:c7:01:1a:33:2d:ad:ee:6a:7a:42:a9:ab:99:
                    55:0a:b6:c6:00:89:2e:ff:a4:b1:ca:5b:24:88:59:
                    b5:4e:9e:0c:92:19:64:11:7e:65:fe:40:76:e1:e9:
                    61:d1:91:b3:7a:b5:23:a3:01:5c:0b:4f:d7:3a:29:
                    ad:12:1e:1a:a8:30:4f:da:4b:2b:ad:66:f1:78:f0:
                    21:7f:27:1e:4d:e6:2f:43:c4:fa:4b:fe:8e:8f:26:
                    d8:6e:20:23:c5:34:a0:67:d9:b7:44:59:05:15:71:
                    5b:3f
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Authority Key Identifier:
                keyid:90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7

            X509v3 Subject Key Identifier:
                48:BB:F2:9D:77:FB:75:61:F4:1B:B8:F0:CD:42:9C:4D:47:33:27:00
            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: 1.3.6.1.4.1.6449.1.2.2.7
                  CPS: https://secure.comodo.com/CPS
                Policy: 2.23.140.1.2.1

            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl

            Authority Information Access:
                CA Issuers - URI:http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt
                OCSP - URI:http://ocsp.comodoca.com

            X509v3 Subject Alternative Name:
                DNS:aftercore.net, DNS:www.aftercore.net
    Signature Algorithm: sha256WithRSAEncryption
         3c:33:da:69:b2:de:d0:2d:12:e3:6c:8a:d0:16:cc:d2:bc:16:
         95:65:c8:51:be:48:0d:11:2b:ed:8d:a8:d1:1c:24:f4:6c:5e:
         82:b3:94:a1:97:b7:6a:bb:ff:d9:59:5a:ff:d9:fb:40:32:16:
         f6:7a:71:94:9d:a8:56:53:95:56:ff:9c:ba:5c:16:a7:60:74:
         53:23:51:71:9f:26:20:dc:50:ca:47:82:97:7f:2b:ae:c6:e9:
         55:cf:51:ec:fc:c4:cc:33:2e:28:6f:02:38:a4:e6:fc:46:a1:
         2c:d4:43:48:46:1d:b7:dd:55:8f:21:24:3c:3c:82:b7:d6:04:
         7d:cd:d1:83:a1:ef:a1:83:61:db:2d:c8:80:14:44:cb:f7:67:
         13:03:16:9b:ad:f7:00:1e:94:4f:9e:2a:b6:fc:1f:e3:70:56:
         f1:32:a7:58:27:7c:98:7e:5d:f4:95:67:87:e2:e7:6c:12:6b:
         cc:30:a5:9e:10:cc:57:8c:4f:c2:cf:44:dd:07:11:7f:f8:97:
         e7:fb:ae:33:44:5b:6d:36:0f:c2:18:36:4a:e0:fe:6e:4f:c6:
         63:dd:5b:07:98:c6:c7:0c:6c:0c:90:07:9f:fe:f9:d6:87:c4:
         2e:04:d7:74:4f:07:1a:4d:c3:a9:68:9c:cb:f9:e3:0a:03:3b:
         f8:c0:bd:59

Certificate:

Data:

Version: 3 (0x2)

Serial Number:

db:47:bd:d1:2e:a1:e6:33:3f:b2:e9:d4:75:82:44:37

Signature Algorithm: sha256WithRSAEncryption

Issuer: C=GB, ST=Greater Manchester, L=Salford, O=COMODO CA Limited, CN=COMODO RSA Domain Validation Secure Server CA

Validity

Not Before: Jun 14 00:00:00 2016 GMT

Not After : Jun 14 23:59:59 2017 GMT

Subject: OU=Domain Control Validated, OU=PositiveSSL, CN=aftercore.net

Subject Public Key Info:

Public Key Algorithm: rsaEncryption

Public-Key: (2048 bit)

Modulus:

00:c8:76:58:2f:3a:a6:d0:b5:7d:b7:fb:09:e3:94:

fa:f5:98:0b:23:58:d3:26:d9:93:8a:5d:a3:06:ee:

83:e1:1d:a8:ce:34:88:5c:e9:c3:68:48:44:8b:0b:

d0:f4:bc:07:b3:81:15:82:d1:90:23:c5:84:93:be:

8a:58:33:84:41:08:76:47:64:f8:d0:3e:ba:73:eb:

90:23:bd:98:19:b2:7a:95:69:a5:b4:f7:a2:fe:f4:

62:16:55:e1:fc:ee:4a:82:97:3c:25:c2:d4:a1:ed:

d5:21:4b:7c:c0:64:61:05:72:cc:7a:4d:89:a8:14:

88:c7:64:fc:5d:b3:72:b0:34:26:67:2f:d3:ac:18:

a4:af:5f:a6:d1:76:72:01:92:d3:8e:cd:35:cf:82:

e3:7a:c7:01:1a:33:2d:ad:ee:6a:7a:42:a9:ab:99:

55:0a:b6:c6:00:89:2e:ff:a4:b1:ca:5b:24:88:59:

b5:4e:9e:0c:92:19:64:11:7e:65:fe:40:76:e1:e9:

61:d1:91:b3:7a:b5:23:a3:01:5c:0b:4f:d7:3a:29:

ad:12:1e:1a:a8:30:4f:da:4b:2b:ad:66:f1:78:f0:

21:7f:27:1e:4d:e6:2f:43:c4:fa:4b:fe:8e:8f:26:

d8:6e:20:23:c5:34:a0:67:d9:b7:44:59:05:15:71:

5b:3f

Exponent: 65537 (0x10001)

X509v3 extensions:

X509v3 Authority Key Identifier:

keyid:90:AF:6A:3A:94:5A:0B:D8:90:EA:12:56:73:DF:43:B4:3A:28:DA:E7

X509v3 Subject Key Identifier:

48:BB:F2:9D:77:FB:75:61:F4:1B:B8:F0:CD:42:9C:4D:47:33:27:00

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: 1.3.6.1.4.1.6449.1.2.2.7

CPS: https://secure.comodo.com/CPS

Policy: 2.23.140.1.2.1

X509v3 CRL Distribution Points:

Full Name:

URI:http://crl.comodoca.com/COMODORSADomainValidationSecureServerCA.crl

Authority Information Access:

CA Issuers - URI:http://crt.comodoca.com/COMODORSADomainValidationSecureServerCA.crt

OCSP - URI:http://ocsp.comodoca.com

X509v3 Subject Alternative Name:

DNS:aftercore.net, DNS:www.aftercore.net

Signature Algorithm: sha256WithRSAEncryption

3c:33:da:69:b2:de:d0:2d:12:e3:6c:8a:d0:16:cc:d2:bc:16:

95:65:c8:51:be:48:0d:11:2b:ed:8d:a8:d1:1c:24:f4:6c:5e:

82:b3:94:a1:97:b7:6a:bb:ff:d9:59:5a:ff:d9:fb:40:32:16:

f6:7a:71:94:9d:a8:56:53:95:56:ff:9c:ba:5c:16:a7:60:74:

53:23:51:71:9f:26:20:dc:50:ca:47:82:97:7f:2b:ae:c6:e9:

55:cf:51:ec:fc:c4:cc:33:2e:28:6f:02:38:a4:e6:fc:46:a1:

2c:d4:43:48:46:1d:b7:dd:55:8f:21:24:3c:3c:82:b7:d6:04:

7d:cd:d1:83:a1:ef:a1:83:61:db:2d:c8:80:14:44:cb:f7:67:

13:03:16:9b:ad:f7:00:1e:94:4f:9e:2a:b6:fc:1f:e3:70:56:

f1:32:a7:58:27:7c:98:7e:5d:f4:95:67:87:e2:e7:6c:12:6b:

cc:30:a5:9e:10:cc:57:8c:4f:c2:cf:44:dd:07:11:7f:f8:97:

e7:fb:ae:33:44:5b:6d:36:0f:c2:18:36:4a:e0:fe:6e:4f:c6:

63:dd:5b:07:98:c6:c7:0c:6c:0c:90:07:9f:fe:f9:d6:87:c4:

2e:04:d7:74:4f:07:1a:4d:c3:a9:68:9c:cb:f9:e3:0a:03:3b:

f8:c0:bd:59

SNOWSKI