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

TLSv1.2

us.edu.pl · 155.158.211.71:443

Verified

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

Subject
C=PL ST=śląskie L=Katowice O=Uniwersytet Śląski w Katowicach CN=*.us.edu.pl
Issuer
C=GR O=Hellenic Academic and Research Institutions CA CN=GEANT TLS ECC 1
Valid from
2026-10-28T09:48:27+00:00
Expires
2027-05-15T09:48:26+00:00
Days remaining
189
Serial (hex)
10CFD72282AF85BC6807F4A525C8F9B3
Signature
ecdsa-with-SHA384
Public key
EC 256 prime256v1

Subject alternative names (SAN)

DNS:*.us.edu.pl, DNS:us.edu.pl

SHA-256 fingerprint

BB:22:48:5D:16:9E:D5:C3:86:61:52:5C:3E:E1:33:DF:33:EF:CF:71:2A:E8:70:94:C2:5C:C4:41:B5:BC:E8:A5
Certificate extensions & PEM
basicConstraints
CA:FALSE
authorityKeyIdentifier
E9:99:06:8D:17:1F:AB:FB:96:1A:5A:C8:5B:5E:5D:5E:EC:DA:9C:8F
authorityInfoAccess
CA Issuers - URI:http://crt.harica.gr/HARICA-GEANT-TLS-E1.cer
subjectAltName
DNS:*.us.edu.pl, DNS:us.edu.pl
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-E1.crl
subjectKeyIdentifier
61:60:5F:41:2B:FA:21:38:7D:28:CB:7B:A0:FA:A5:8B:EB:73:E9:AC
keyUsage
Digital Signature
ct_precert_scts
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 : Oct 28 09:58:28.868 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:9A:AE:92:83:81:84:B7:B1:8E:A7:87: 7A:DB:C5:AE:89:5C:C9:5D:1D:97:44:7D:47:DF:C5:5E: 61:FA:09:A7:86:02:20:67:26:81:A0:1A:26:C1:4F:3E: 9B:38:72:26:42:96:93:7F:4E:13:53:E4:4A:4D:73:75: 3D:A8:8F:5E:68:1C:F0 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D6:D5:8D:A9:D0:17:53:F3:6A:4A:A0:C7:57:49:02:AF: EB:C7:DC:2C:D3:8C:D9:F7:64:C8:0C:89:19:1E:9F:02 Timestamp : Oct 28 09:58:28.860 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:DC:77:95:ED:EF:53:E7:E7:D5:EC:82: 0C:E0:E2:D0:56:73:61:D7:52:6C:A1:7D:C2:07:FD:A5: F8:52:50:EF:E0:02:21:00:93:38:7B:6E:9F:BB:0E:A0: DE:93:1E:88:FB:67:83:B4:B3:D0:9E:2F:79:02:8E:7F: 8E:B6:66:24:FB:F1:18:35 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 : Oct 28 09:58:28.912 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:09:0F:88:3B:BD:AA:6E:61:EC:6B:ED:B4: 09:8D:EA:99:7E:F7:2A:33:2F:A0:8C:AA:A9:7D:69:1D: D1:4B:69:D4:02:21:00:F6:F6:66:23:AD:75:8C:D6:0A: F1:41:46:92:DD:DB:A3:07:57:39:B9:A4:19:C4:D3:B6: E3:1F:99:61:CA:BF:2E
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-ECDSA-CHACHA20-POLY1305 · Checked 2026-11-07T06:53:52+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=GR O=Hellenic Academic and Research Institutions CA CN=GEANT TLS ECC 1
Issuer
C=GR O=Hellenic Academic and Research Institutions CA CN=HARICA TLS ECC Root CA 2021
Valid from
2025-01-03T11:14:21+00:00
Expires
2039-12-31T11:14:20+00:00
Days remaining
4802
Serial (hex)
42FDDCE1261607E1A5E6935A400161DD
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

6C:DF:0B:A1:71:1E:85:6D:22:8B:A0:0C:A0:4C:5C:1C:3D:79:94:4C:03:7B:71:3B:15:5A:4E:E4:B4:7E:C5:3C
Certificate extensions & PEM
basicConstraints
CA:TRUE, pathlen:0
authorityKeyIdentifier
C9:1B:53:81:12:FE:04:D5:16:D1:AA:BC:9A:6F:B7:A0:95:19:6E:CA
authorityInfoAccess
CA Issuers - URI:http://crt.harica.gr/HARICA-TLS-Root-2021-ECC.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-ECC.crl
subjectKeyIdentifier
E9:99:06:8D:17:1F:AB:FB:96:1A:5A:C8:5B:5E:5D:5E:EC:DA:9C:8F
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 ECC Root CA 2021
Issuer
C=GR L=Athens O=Hellenic Academic and Research Institutions Cert. Authority CN=Hellenic Academic and Research Institutions ECC RootCA 2015
Valid from
2021-09-02T07:44:37+00:00
Expires
2029-08-31T07:44:36+00:00
Days remaining
1028
Serial (hex)
716027C8857A73542DEF516C1C2EEB0F
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

50:E2:7F:90:EB:6A:F4:95:B0:E6:EE:B6:55:CC:89:44:4C:27:D3:C9:5B:68:23:FA:02:AB:DC:95:F1:63:6A:E1
Certificate extensions & PEM
basicConstraints
CA:TRUE
authorityKeyIdentifier
B4:22:0B:82:99:24:01:0E:9C:BB:E4:0E:FD:BF:FB:97:20:93:99:2A
authorityInfoAccess
CA Issuers - URI:http://repo.harica.gr/certs/HaricaECCRootCA2015.crt
certificatePolicies
Policy: X509v3 Any Policy
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
crlDistributionPoints
Full Name: URI:http://crl.harica.gr/HaricaECCRootCA2015.crl
subjectKeyIdentifier
C9:1B:53:81:12:FE:04:D5:16:D1:AA:BC:9A:6F:B7:A0:95:19:6E:CA
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

Registration / WHOIS →DNS records →