SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
csioz.gov.pl
SSL/TLS Certificate
SSL/TLS Certificate for csioz.gov.pl
Valid- Issued by (CA)
- Asseco Data Systems S.A.
- Subject
- *.csioz.gov.pl
- Valid from
- Nov 7, 2025
- Valid until
- Nov 7, 2026 (107 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 15AA2FF8CF238FF1A796F1E960CB15F1
- SHA-256 fingerprint
- E6:75:5E:82:28:7E:32:D7:0E:BA:07:D6:64:03:00:A2:63:C1:D9:EC:E6:CF:01:0A:3A:8B:27:45:45:B9:12:32
- Chain
- Certum OV TLS G2 R39 CA → Certum Trusted Root CA
Certificate Authority Authorization (CAA)
CAA restricts issuance to certum.pl; we couldn't map the serving CA (Asseco Data Systems S.A.) to one of these identifiers.
Never get surprised by csioz.gov.pl's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch csioz.gov.pl continuously, notifying you the moment anything moves across all three signals:
Uptime
We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.
DNS changes
We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.
TLS certificate
We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.
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