DNS
THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.3

fh-koeln.de · 139.6.10.199:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
C=DE ST=Nordrhein-Westfalen O=Technische Hochschule Koeln CN=th-koeln.de
Issuer
C=GR O=Hellenic Academic and Research Institutions CA CN=GEANT TLS RSA 1
Valid from
2026-09-10T01:52:44+00:00
Expires
2027-03-28T01:52:43+00:00
Days remaining
186
Serial (hex)
3EDAFD906A6340CD4BAA0373108BC448
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:th-koeln.de, DNS:fh-koeln.de, DNS:www.fh-koeln.de, DNS:www.th-koeln.de

SHA-256 fingerprint

00:6D:A1:B8:B6:F2:E9:B5:01:9D:79:A2:8A:F9:B8:1C:7F:60:35:0E:0E:E2:63:CA:11:84:65:34:E2:6A:AA:42
Certificate extensions & PEM
basicConstraints
CA:FALSE
authorityKeyIdentifier
86:01:72:3F:8C:A9:70:E2:31:06:53:16:CE:01:5F:5B:79:C8:3C:3B
authorityInfoAccess
CA Issuers - URI:http://crt.harica.gr/HARICA-GEANT-TLS-R1.cer
subjectAltName
DNS:th-koeln.de, DNS:fh-koeln.de, DNS:www.fh-koeln.de, DNS:www.th-koeln.de
certificatePolicies
Policy: 2.23.140.1.2.2 Policy: 0.4.0.2042.1.7 Policy: 1.3.6.1.4.1.26513.1.1.1.2
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
crlDistributionPoints
Full Name: URI:http://crl.harica.gr/HARICA-GEANT-TLS-R1.crl
subjectKeyIdentifier
EB:74:2B:A3:55:F0:01:E9:28:E3:BC:6C:D1:52:EA:87:00:26:B2:32
keyUsage
Digital Signature, Key Encipherment
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 60:4C:9A:AF:7A:7F:77:5F:01:D4:06:FC:92:0D:C8:99: EB:0B:1C:7D:F8:C9:52:1B:FA:FA:17:77:3B:97:8B:C9 Timestamp : Sep 10 02:02:45.728 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:AE:6B:C9:8C:D8:25:A0:F5:2F:42:28: 5A:CB:B1:24:F3:22:07:91:AC:DD:33:CB:21:D4:B7:1F: 12:C5:18:CA:21:02:20:44:47:0F:CF:3F:51:72:6B:37: 5C:72:6C:BE:E9:1A:19:C8:E2:F4:67:C6:33:CE:A5:84: 18:68:6D:93:0E:13:B6 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 46:A2:39:67:C6:0D:B6:46:87:C6:6F:3D:F9:99:94:76: 93:A6:A6:11:20:84:57:D5:55:E7:E3:D0:A1:D9:B6:46 Timestamp : Sep 10 02:02:45.756 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:44:D3:30:B2:9A:97:2F:25:58:54:6C:1C: 25:DB:69:59:3D:A8:0D:36:60:6E:10:D3:A6:4F:05:A4: 94:86:A6:E1:02:20:59:E7:37:2E:CA:CC:E2:C5:17:51: 17:77:00:93:82:86:5E:7A:B1:00:EF:84:28:F9:CE:D5: 81:CB:6D:DC:69:6A Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 44:C2:BD:0C:E9:14:0E:64:A5:C9:4A:01:93:0A:5A:A1: BB:35:97:0E:00:EE:11:16:89:68:2A:1C:44:D7:B5:66 Timestamp : Sep 10 02:02:45.708 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:78:A1:D7:13:25:F6:11:48:80:CB:D9:D4: 7F:22:74:AD:9B:E7:EB:27:22:01:6D:1E:71:88:2D:33: E9:98:8B:49:02:20:1C:86:6E:9A:BF:64:64:C2:6B:BE: B5:F8:9C:BB:C6:6A:C7:6C:C6:70:B4:11:41:A8:0B:15: 8B:55:0F:62:9B:65
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-22T20:47:14+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=GR O=Hellenic Academic and Research Institutions CA CN=GEANT TLS RSA 1
Issuer
C=GR O=Hellenic Academic and Research Institutions CA CN=HARICA TLS RSA Root CA 2021
Valid from
2025-01-03T11:15:00+00:00
Expires
2039-12-31T11:14:59+00:00
Days remaining
4847
Serial (hex)
14D57BF3692228219A5567FA91651B22
Signature
RSA-SHA256
Public key
RSA 3072

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

5B:67:8D:C4:40:95:A5:28:95:B6:3B:31:F2:72:27:F4:B3:6C:3E:34:74:91:BF:2B:FA:69:18:37:A5:FB:8C:79
Certificate extensions & PEM
basicConstraints
CA:TRUE, pathlen:0
authorityKeyIdentifier
0A:48:23:A6:60:A4:92:0A:33:EA:93:5B:C5:57:EA:25:4D:BD:12:EE
authorityInfoAccess
CA Issuers - URI:http://crt.harica.gr/HARICA-TLS-Root-2021-RSA.cer
certificatePolicies
Policy: X509v3 Any Policy
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
crlDistributionPoints
Full Name: URI:http://crl.harica.gr/HARICA-TLS-Root-2021-RSA.crl
subjectKeyIdentifier
86:01:72:3F:8C:A9:70:E2:31:06:53:16:CE:01:5F:5B:79:C8:3C:3B
keyUsage
Digital Signature, Certificate Sign, CRL Sign
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=GR O=Hellenic Academic and Research Institutions CA CN=HARICA TLS RSA Root CA 2021
Issuer
C=GR L=Athens O=Hellenic Academic and Research Institutions Cert. Authority CN=Hellenic Academic and Research Institutions RootCA 2015
Valid from
2021-09-02T07:41:55+00:00
Expires
2029-08-31T07:41:54+00:00
Days remaining
1073
Serial (hex)
2A6086D4D4DE45C95E4B98FBBF2FBF26
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

4A:CD:8D:C6:02:0A:54:5A:85:89:43:A5:53:B5:E0:F3:FC:5B:85:9A:EA:17:46:65:0D:69:CF:12:10:F9:56:D8
Certificate extensions & PEM
basicConstraints
CA:TRUE
authorityKeyIdentifier
71:15:67:C8:C8:C9:BD:75:5D:72:D0:38:18:6A:9D:F3:71:24:54:0B
authorityInfoAccess
CA Issuers - URI:http://repo.harica.gr/certs/HaricaRootCA2015.crt
certificatePolicies
Policy: X509v3 Any Policy
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
crlDistributionPoints
Full Name: URI:http://crl.harica.gr/HaricaRootCA2015.crl
subjectKeyIdentifier
0A:48:23:A6:60:A4:92:0A:33:EA:93:5B:C5:57:EA:25:4D:BD:12:EE
keyUsage
Digital Signature, Certificate Sign, CRL Sign
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

View certificate JSON

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