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

master.cz · 80.79.16.235:443

Verified

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

Subject
CN=*.master.cz
Issuer
C=PL O=Asseco Data Systems S.A. CN=Certum DV TLS G2 R39 CA
Valid from
2026-07-09T12:04:27+00:00
Expires
2027-01-24T12:04:26+00:00
Days remaining
120
Serial (hex)
08BD85F86939163889D11E070A6D5021
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.master.cz, DNS:master.cz

SHA-256 fingerprint

3C:F4:F5:AD:89:98:BA:22:98:70:43:38:00:BC:B3:80:81:52:10:D5:26:2D:CF:67:95:3D:AE:E6:03:0F:FE:D1
Certificate extensions & PEM
basicConstraints
CA:FALSE
crlDistributionPoints
Full Name: URI:http://certumdvtlsg2r39ca.crl.certum.pl/certumdvtlsg2r39ca.crl
authorityInfoAccess
OCSP - URI:http://certumdvtlsg2r39ca.ocsp-certum.com CA Issuers - URI:http://certumdvtlsg2r39ca.repository.certum.pl/certumdvtlsg2r39ca.cer
authorityKeyIdentifier
33:A8:77:B7:01:38:6F:5F:1F:24:24:A2:1E:6C:14:E3:6E:22:03:DF
certificatePolicies
Policy: 2.23.140.1.2.1 Policy: 1.2.616.1.113527.2.101.1
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
keyUsage
Digital Signature, Key Encipherment
subjectAltName
DNS:*.master.cz, DNS:master.cz
ct_precert_scts
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 : Jul 9 12:04:28.522 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:F9:6C:8A:FA:63:17:3E:C2:22:10:5A: 12:59:E9:BB:18:95:3A:7B:3E:39:39:C7:38:12:78:B0: 6B:43:8C:91:59:02:21:00:8D:2D:3C:F1:62:1E:AF:58: 77:B1:74:12:6E:49:35:B0:28:79:F7:E0:80:12:EA:F9: B6:F6:0B:A7:A0:F5:31:F4 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1C:9F:68:2C:E9:FA:F0:45:69:50:F8:1B:96:8A:87:DD: DB:32:10:D8:4C:E6:C8:B2:E3:82:52:4A:C4:CF:59:9F Timestamp : Jul 9 12:04:28.741 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:F3:CD:E9:DF:43:72:87:DB:0A:F5:64: FC:00:DA:66:8C:4A:55:64:D7:B2:11:52:A2:78:29:CC: 45:28:D1:DE:7C:02:20:55:CB:D0:74:F0:5C:36:CE:2A: 9B:6C:F1:B9:3E:66:66:76:8D:D9:ED:29:1E:48:11:C1: E4:33:7D:C8:17:9B:F0 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 : Jul 9 12:04:28.484 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:DA:9B:76:8E:7F:95:7F:E2:A3:4E:B9: 28:39:EC:B4:FE:9C:35:05:E8:5D:0A:F3:85:A3:37:C3: DF:0C:F3:7E:03:02:21:00:92:E6:7C:D9:A6:57:A8:F7: 24:07:AB:77:A5:0A:32:80:75:3D:F6:7A:79:C1:30:A3: 73:12:8F:33:DF:E4:97:15
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-25T18:14:22+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=PL O=Asseco Data Systems S.A. CN=Certum DV TLS G2 R39 CA
Issuer
C=PL O=Asseco Data Systems S.A. OU=Certum Certification Authority CN=Certum Trusted Root CA
Valid from
2024-06-18T07:41:22+00:00
Expires
2039-06-05T07:41:22+00:00
Days remaining
4635
Serial (hex)
A82DD9E5DCAFDF13205E70043E6B95A8
Signature
RSA-SHA512
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

83:C0:A5:A7:68:44:C8:40:DF:AF:82:0F:FD:02:AD:F6:57:3A:26:82:3E:F6:AF:75:8A:33:84:A0:AC:04:40:83
Certificate extensions & PEM
authorityInfoAccess
CA Issuers - URI:http://subca.repository.certum.pl/ctrca.cer OCSP - URI:http://subca.ocsp-certum.com
authorityKeyIdentifier
8C:FB:1C:75:BC:02:D3:9F:4E:2E:48:D9:F9:60:54:AA:C4:B3:4F:FA
basicConstraints
CA:TRUE, pathlen:0
crlDistributionPoints
Full Name: URI:http://subca.crl.certum.pl/ctrca.crl
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
keyUsage
Certificate Sign, CRL Sign
certificatePolicies
Policy: X509v3 Any Policy
subjectKeyIdentifier
33:A8:77:B7:01:38:6F:5F:1F:24:24:A2:1E:6C:14:E3:6E:22:03:DF
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=PL O=Asseco Data Systems S.A. OU=Certum Certification Authority CN=Certum Trusted Root CA
Issuer
C=PL O=Unizeto Technologies S.A. OU=Certum Certification Authority CN=Certum Trusted Network CA
Valid from
2023-09-19T10:00:00+00:00
Expires
2028-09-19T10:00:00+00:00
Days remaining
724
Serial (hex)
D8E0744B5824919FBD08847DF72020FA
Signature
RSA-SHA512
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

FB:13:89:0C:7A:B1:4F:F7:B9:4B:27:14:50:3E:31:12:3B:FD:D3:40:FC:4D:97:97:43:16:6E:04:69:B4:7A:88
Certificate extensions & PEM
basicConstraints
CA:TRUE
subjectKeyIdentifier
8C:FB:1C:75:BC:02:D3:9F:4E:2E:48:D9:F9:60:54:AA:C4:B3:4F:FA
authorityKeyIdentifier
08:76:CD:CB:07:FF:24:F6:C5:CD:ED:BB:90:BC:E2:84:37:46:75:F7
keyUsage
Certificate Sign, CRL Sign
crlDistributionPoints
Full Name: URI:http://crl.certum.pl/ctnca.crl
authorityInfoAccess
OCSP - URI:http://subca.ocsp-certum.com CA Issuers - URI:http://repository.certum.pl/ctnca.cer
certificatePolicies
Policy: X509v3 Any Policy CPS: https://www.certum.pl/CPS
-----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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