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

cesnet.cz · 78.128.246.93:443

Verified

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

Subject
C=CZ L=Praha 6 O=CESNET CN=www.cesnet.cz
Issuer
C=GR O=Hellenic Academic and Research Institutions CA CN=GEANT TLS RSA 1
Valid from
2026-02-20T12:54:55+00:00
Expires
2027-02-20T12:54:55+00:00
Days remaining
147
Serial (hex)
5A9AE3B6736FA70CCECB9E2D8D2E4BD8
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:www.cesnet.cz, DNS:nren.cz, DNS:cesnet.cz, DNS:www.nren.cz, DNS:www.ten.cz

SHA-256 fingerprint

9B:54:EA:D3:F8:1A:A5:48:B6:DD:8F:4E:B2:4C:99:CE:4D:E3:4B:CB:4A:A2:3D:B4:DB:F8:4F:33:58:3F:AF:32
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 OCSP - URI:http://ocsp-tls.harica.gr
subjectAltName
DNS:www.cesnet.cz, DNS:nren.cz, DNS:cesnet.cz, DNS:www.nren.cz, DNS:www.ten.cz
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
65:8E:D3:04:FC:02:BA:62:46:C9:85:C0:35:37:4C:0A:CF:61:CD:E1
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 : Feb 20 13:04:56.995 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:24:15:CA:84:94:CC:E1:0D:27:DE:78:24: F4:82:8B:10:F1:01:4C:70:3D:79:34:78:55:66:DD:B8: 72:D1:CE:13:02:21:00:DB:FB:BE:E5:9C:9E:25:EE:8C: 9B:95:70:B9:A8:BF:33:22:9B:7F:30:E0:36:F8:25:B1: 1C:A0:62:D3:C2:8A:35 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 : Feb 20 13:04:56.914 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:9E:AF:3C:ED:94:A2:D2:A9:89:31:0F: 95:50:AA:80:52:00:50:FD:70:68:E8:9A:10:08:8A:F7: 95:A2:D4:06:F3:02:21:00:CC:19:A1:B0:F5:60:9C:04: 38:EB:F3:DA:EB:A2:77:7A:64:F0:AC:6C:7C:CC:0F:06: 55:DD:5E:28:0A:1A:44:AE Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F: AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26 Timestamp : Feb 20 13:04:57.014 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:00:CC:30:FF:DD:5C:DC:2E:31:DE:B3:86: 9C:54:9D:FA:4E:D6:17:CB:64:B3:A7:E4:E0:9D:37:B2: A8:3E:30:7D:02:21:00:F1:29:C4:7C:33:24:92:4C:5F: EC:AC:2C:02:F6:3B:CB:94:B7:4D:27:36:A7:4D:72:AB: 84:3D:DE:A7:E6:A2:8D
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-26T06:32:08+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
4844
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
1070
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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