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

mx1.netart.com · 85.128.131.200:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. Peer certificate CN=`*.netart.pl' did not match expected CN=`mx1.netart.com'

Certificate verification failed

Subject
CN=*.netart.pl
Issuer
C=PL O=nazwa.pl Sp. z o.o. CN=nazwaSSL DV TLS G2 R29 CA
Valid from
2026-04-13T08:24:11+00:00
Expires
2026-10-29T08:24:10+00:00
Days remaining
30
Serial (hex)
6D8B2E5169C6371DAA8E68B94FF6C379
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.netart.pl, DNS:netart.pl

SHA-256 fingerprint

C6:1E:A5:BF:E0:F5:8D:8B:6F:40:F4:FE:33:E8:64:C2:CB:B2:E2:90:ED:6B:AB:29:03:6E:2B:AD:46:44:65:1B
Certificate extensions & PEM
basicConstraints
CA:FALSE
crlDistributionPoints
Full Name: URI:http://nazwassldvtlsg2r29ca.crl.certum.pl/nazwassldvtlsg2r29ca.crl
authorityInfoAccess
OCSP - URI:http://nazwassldvtlsg2r29ca.ocsp-certum.com CA Issuers - URI:http://nazwassldvtlsg2r29ca.repository.certum.pl/nazwassldvtlsg2r29ca.cer
authorityKeyIdentifier
F9:51:FB:C9:4B:F3:2F:5C:CE:0F:0D:C3:22:D9:B7:4B:27:BC:C1:AA
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:*.netart.pl, DNS:netart.pl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : AF:67:88:3B:57:B0:4E:DD:8F:A6:D9:7E:F6:2E:A8:EB: 81:0A:C7:71:60:F0:24:5E:55:D6:0C:2F:E7:85:87:3A Timestamp : Apr 13 08:24:11.778 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:94:72:FE:1B:AB:2C:9B:41:83:84:D8: 03:97:A1:25:A3:BA:59:05:F2:BE:9A:40:00:96:A4:66: 28:93:2A:1E:09:02:21:00:B1:DA:D7:79:D4:5D:76:AF: B3:C4:15:78:CE:77:A5:B8:4B:A1:D6:82:7A:74:C3:B3: FE:2F:24:CF:90:1A:CD:72 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : Apr 13 08:24:11.807 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:28:8C:F9:66:0E:BA:A5:D4:27:C3:2C:47: AE:F1:A4:0B:02:31:33:D6:3D:D4:57:F2:81:0F:F2:FC: F0:34:75:A3:02:20:63:1F:0E:59:3F:3B:56:30:6C:29: DB:82:07:52:65:29:A9:E4:E9:BE:A7:AF:86:7F:37:1D: 9E:2C:49:FA:9A:85 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D8:09:55:3B:94:4F:7A:FF:C8:16:19:6F:94:4F:85:AB: B0:F8:FC:5E:87:55:26:0F:15:D1:2E:72:BB:45:4B:14 Timestamp : Apr 13 08:24:11.851 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:3E:BE:A9:57:93:60:4E:61:A5:76:B6:49: 7B:9A:3F:D2:C9:C9:DD:17:CE:42:57:9D:02:1B:49:2D: 24:ED:30:A6:02:20:08:89:07:09:F1:80:C8:77:2F:92: CC:A7:70:F0:92:03:02:51:E6:8D:4F:FC:EB:4E:70:69: D5:F7:9B:0C:04:E6
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-29T07:35:04+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=PL O=nazwa.pl Sp. z o.o. CN=nazwaSSL DV TLS G2 R29 CA
Issuer
C=PL O=Asseco Data Systems S.A. OU=Certum Certification Authority CN=Certum Trusted Root CA
Valid from
2024-08-20T09:30:12+00:00
Expires
2029-08-14T09:30:12+00:00
Days remaining
1050
Serial (hex)
A18B344928074C327BDA047EE59104CE
Signature
RSA-SHA512
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

AA:0C:4B:78:01:B0:9F:B7:7E:42:3C:91:33:1E:FB:62:A5:A2:A8:B2:3A:9D:7C:99:7E:6A:9B:EE:A4:35:D2:BF
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
F9:51:FB:C9:4B:F3:2F:5C:CE:0F:0D:C3:22:D9:B7:4B:27:BC:C1:AA
-----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
721
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-----
MIIFxDCCBKygAwIBAgIRANjgdEtYJJGfvQiEffcgIPowDQYJKoZIhvcNAQENBQAw
fjELMAkGA1UEBhMCUEwxIjAgBgNVBAoTGVVuaXpldG8gVGVjaG5vbG9naWVzIFMu
QS4xJzAlBgNVBAsTHkNlcnR1bSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTEiMCAG
A1UEAxMZQ2VydHVtIFRydXN0ZWQgTmV0d29yayBDQTAeFw0yMzA5MTkxMDAwMDBa
Fw0yODA5MTkxMDAwMDBaMHoxCzAJBgNVBAYTAlBMMSEwHwYDVQQKExhBc3NlY28g
RGF0YSBTeXN0ZW1zIFMuQS4xJzAlBgNVBAsTHkNlcnR1bSBDZXJ0aWZpY2F0aW9u
IEF1dGhvcml0eTEfMB0GA1UEAxMWQ2VydHVtIFRydXN0ZWQgUm9vdCBDQTCCAiIw
DQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIBANEtjru3NuptN5GfTpOnBeQpAyXO
HIL3fJmfQQbN7aO6wNsJLMF83yl+S2Uvk6fUAWsDKBij2J0FwSrYRfGR3t870IAC
jM84D+qnXHgRpMHIhVwl09Oy5yXPEVSXqzXAHnYc7wBTnzncFKUsIiWzcnL8jbPl
PggeFCo3C4g8yrD0yMKhrrzBvilnVeL8rVlc/r1XLLCQjcLtN7Z8mYi11QOaPRUN
PTqoqEXwlU4lWR3NmGm708wyyY3vgf6tfYm7umATymWVZ6DzGfYDVtRq0yfioa2D
8EoSInccBXPiGXFCwOx1RpqQWOBqjiulRjAEjhmyF+O+qbp/VvEkA9eyISh2DjYw
THnVQZqaqLg1ugw68kQbIIj3xSXXPcbjPkPdh/7E6vVTPkxl/ztKy3haaxdfDcfD
T06aKqLtV00i4kaaPw+RNCR9VeOMlTfTGvAJKyzSyY20DQCrZyko2AH1GQS2Hb52
/nJcxIXK0oBB3wWoo9WEkE8L8+A/mxnSN4k/8ntSHIz24fc8B5eMDqJZgQyykD3T
41lG7Q+pp96Aa1qqB7YZy7xX85chegyxK3Q+69qnZy1MxJieNgl2Zmb8Gj/qSFQc
vjC9gFC/fLXOAPYMYdnnJAPg4wGBDr3YhTSIvbI2qHtcCOVEgIxv+C/VIcodHND7
xLWH0TpOx3a1NUi1AgMBAAGjggE/MIIBOzAPBgNVHRMBAf8EBTADAQH/MB0GA1Ud
DgQWBBSM+xx1vALTn04uSNn5YFSqxLNP+jAfBgNVHSMEGDAWgBQIds3LB/8k9sXN
7buQvOKEN0Z19zAOBgNVHQ8BAf8EBAMCAQYwLwYDVR0fBCgwJjAkoCKgIIYeaHR0
cDovL2NybC5jZXJ0dW0ucGwvY3RuY2EuY3JsMGsGCCsGAQUFBwEBBF8wXTAoBggr
BgEFBQcwAYYcaHR0cDovL3N1YmNhLm9jc3AtY2VydHVtLmNvbTAxBggrBgEFBQcw
AoYlaHR0cDovL3JlcG9zaXRvcnkuY2VydHVtLnBsL2N0bmNhLmNlcjA6BgNVHSAE
MzAxMC8GBFUdIAAwJzAlBggrBgEFBQcCARYZaHR0cHM6Ly93d3cuY2VydHVtLnBs
L0NQUzANBgkqhkiG9w0BAQ0FAAOCAQEAKPpdjKpRGqa+eIZpwndaFy+p4H1FT2wf
9JOJdmyjSkJ4wlUp+xbL6v7D6/6xYO8IcvyWyR1sdqef8HK49mYK9jDjk+ypq7IO
h8R9VbhSuS6KxY3X5lVV6vmYZ6QE4G8IuK9ktvGSVS4uNabf+/r+Gq9oiysCwsck
AsjwXbYN2gsKAWxXGC1vAqIOlB3tJaL29UVh2nKdl0eD7EsFwbk0vo/U5pQ/Yi8u
JJb/OSiK1XXUJ7S8wmURNWK2hIzHSnP9xotjmUJMVMb8Igj8jntZNc9U3lNuzG6R
F2kSR3FCgnCJ9AebGFZwEc7QDTCuohG6Lmb6D3Dtopv/LvqypxAmQQ==
-----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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