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

mail1.ut.ac.kr · 210.119.144.20:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. SSL operation failed with code 1. OpenSSL Error messages: error:0A000086:SSL routines::certificate verify failed

Certificate verification failed

Subject
C=KR L=Seoul OU=AntiSpam Lab CN=Unknown
Issuer
C=KR L=Seoul OU=AntiSpam Lab CN=Unknown
Valid from
2023-01-11T01:47:29+00:00
Expires
2033-01-08T01:47:29+00:00
Days remaining
2273
Serial (hex)
72016B24D0388D7AF317BBD0BCE6B0BCA3E99276
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

21:92:5B:43:60:D3:C6:64:47:DE:C0:20:3A:BF:85:35:AD:69:05:4D:D3:39:C8:83:7A:8E:7E:6E:59:CB:B3:4F
Certificate extensions & PEM
subjectKeyIdentifier
7D:F4:35:FB:DC:0A:8B:64:A1:A9:B0:1B:A1:5C:51:2E:50:AF:DA:76
authorityKeyIdentifier
7D:F4:35:FB:DC:0A:8B:64:A1:A9:B0:1B:A1:5C:51:2E:50:AF:DA:76
basicConstraints
CA:TRUE
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_128_GCM_SHA256 · Checked 2026-10-18T07:14:21+00:00

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

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