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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

mail.optik.net.ua · 81.17.128.4:443

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
CN=mail.optik.net.ua
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-09-23T23:38:31+00:00
Expires
2026-12-22T23:38:30+00:00
Days remaining
61
Serial (hex)
063D0DE02B2FA67391C70201C4A43A7BA374
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.optik.net.ua

SHA-256 fingerprint

92:C9:E5:6C:F7:18:87:9C:DE:93:58:C6:35:D3:EF:C6:CC:DC:82:FC:3A:17:FF:3D:31:5F:04:39:95:96:D4:4A
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
E5:6A:BE:50:8D:C0:C8:B3:F9:05:76:F8:8F:30:6E:58:C6:B1:32:F8
authorityKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityInfoAccess
CA Issuers - URI:http://yr1.i.lencr.org/
subjectAltName
DNS:mail.optik.net.ua
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/117.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 94:4E:43:87:FA:EC:C1:EF:81:F3:19:24:26:A8:18:65: 01:C7:D3:5F:38:02:01:3F:72:67:7D:55:37:2E:19:D8 Timestamp : Sep 24 00:37:01.400 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:0D:23:08:17:15:E6:C1:7D:7F:C1:B3:92: DB:B1:EA:1D:54:19:8B:11:8C:55:5D:8E:72:4D:1A:24: A0:CB:27:F6:02:21:00:83:37:A6:57:57:B3:6D:5F:84: 67:33:B4:CF:2F:EE:D5:5D:B3:4F:6F:8C:E4:AE:84:F7: 33:A3:FB:D4:05:C4:41 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 8E:CA:47:0B:AC:DE:6A:F3:A2:06:B0:A4:7A:84:B7:46: FE:1F:C6:BF:95:3E:25:E6:9B:4E:E4:02:48:F3:C6:E8 Timestamp : Sep 24 00:37:01.861 2026 GMT Extensions: 00:00:05:00:13:9D:E8:E4 Signature : ecdsa-with-SHA256 30:45:02:20:21:34:79:58:49:CF:04:14:DD:6F:D6:70: 4C:E9:0C:A1:74:F0:6B:00:75:E9:C8:D4:91:CE:DE:CF: 42:D8:38:C2:02:21:00:F0:FE:FA:05:55:B6:03:CA:8F: 1F:A8:1A:D4:CF:4B:6A:CD:42:10:F5:A4:70:FB:06:32: FD:E1:9F:2F:CD:4E:FC
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES128-GCM-SHA256 · Checked 2026-10-22T03:29:52+00:00

Server-presented chain · 1 additional certificate

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR1
Issuer
C=US O=ISRG CN=Root YR
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
681
Serial (hex)
A20253F15F2691C05DC1CE13B9BCCA4E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

13:94:96:34:D9:9C:D6:FD:6A:A8:0B:C0:34:FE:FA:CC:EB:19:69:FE:EF:98:65:86:71:3E:CD:BB:05:75:8D:3F
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityInfoAccess
CA Issuers - URI:http://yr.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr.c.lencr.org/ 
-----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.

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