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

TLSv1.2

mail.zummer.su · 178.216.153.115:443

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.zummer.su
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-10-04T06:29:18+00:00
Expires
2027-01-02T06:29:17+00:00
Days remaining
57
Serial (hex)
0571CC11BA1E01D3EB1218FD1760C33F41F3
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.zummer.su

SHA-256 fingerprint

81:62:F9:B5:96:89:33:E0:8A:2D:ED:A9:A8:E3:E6:D5:A0:A9:AE:BA:8B:BD:D0:92:07:B5:23:1A:25:A3:B8:3D
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
F5:C7:79:2A:8C:88:98:20:DA:4C:40:48:C5:0D:70:BD:E5:5F:57:7D
authorityKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityInfoAccess
CA Issuers - URI:http://yr2.i.lencr.org/
subjectAltName
DNS:mail.zummer.su
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/116.crl
ct_precert_scts
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 : Oct 4 07:27:48.861 2026 GMT Extensions: 00:00:05:00:1B:AF:83:63 Signature : ecdsa-with-SHA256 30:44:02:20:06:E4:F3:7E:1F:F5:BB:12:D9:0E:1E:E3: 2D:EF:89:04:82:FA:96:D5:FC:25:73:7B:E2:6E:E0:3C: 27:F0:87:C2:02:20:29:4F:E7:8C:7C:E2:AC:F8:BD:90: FA:AC:36:61:D1:24:68:DF:3F:02:EE:E6:EF:A5:56:78: AC:4C:BC:DB:8F:BB Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 60:4C:9A:AF:7A:7F:77:5F:01:D4:06:FC:92:0D:C8:99: EB:0B:1C:7D:F8:C9:52:1B:FA:FA:17:77:3B:97:8B:C9 Timestamp : Oct 4 07:27:49.010 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:7B:10:E3:E3:39:8E:8B:2C:C2:F7:3F:3D: C9:4B:16:7A:46:4D:F8:9C:EC:F4:86:93:8E:0D:D1:AE: 16:26:70:A1:02:21:00:DB:15:5B:06:29:CE:8B:C5:DB: E4:5C:F6:DD:B8:E5:BA:A4:CE:E6:49:5A:78:A2:0C:81: 46:02:38:E0:69:28:E6
-----BEGIN CERTIFICATE-----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yQAAAaEFz9USAAAEAwBHMEUCIHsQ4+M5josswvc/PclLFnpGTfic7PSGk44N0a4W
JnChAiEA2xVbBinOi8Xb5Fz23bjluqTO5klaeKIMgUYCOOBpKOYwDQYJKoZIhvcN
AQELBQADggEBAFJ5i+yeSKDTUohImU+yYI9UMShi2lkPZnPovtYzjSKmDDdT0cm0
aH2w6eH3ppEKFWJIkVh2ph5jBddgRVl3cePJOcJgVqjKS/u0YQN59fV01tHrrePg
1WG+QnxxNRA7HTT9fkag58IQagFhespbCJs+n5yA1tNVwj9o6z22ZsDKf+QtzhCP
/7QUPgM1cBwMDeONH9waK1MqRBBcb08c+cUU7JI7zqQ+NhU0E32aErxr57Zhjrhj
TgL0SpfHzphmd0gaTlzb3vbXXJ2gP94OBY4065pW8MRR4O7HiBAWSN8w/Xas/PlP
ywdPbIJmDp2GOAuwxPmS/YHcqdSM5WDhDSM=
-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES256-GCM-SHA384 · Checked 2026-11-06T05:44:40+00:00

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

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