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

a2b-internet.com · 185.40.57.253:443

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=a2b-internet.com
Issuer
C=GB O=Sectigo Limited CN=Sectigo Public Server Authentication CA DV R36
Valid from
2026-01-13T00:00:00+00:00
Expires
2027-01-21T23:59:59+00:00
Days remaining
121
Serial (hex)
42933F04E238AD92038FA9EF2484EEC9
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:a2b-internet.com, DNS:www.a2b-internet.com

SHA-256 fingerprint

15:03:E3:CF:82:1C:2E:42:17:3E:94:D2:17:92:BB:B0:7F:E9:0E:87:64:B8:CB:84:E0:C6:70:08:38:19:58:B1
Certificate extensions & PEM
authorityKeyIdentifier
68:C0:12:16:18:0E:AF:CE:F6:87:A6:32:57:A3:46:51:5D:CB:07:27
subjectKeyIdentifier
34:F1:1F:25:66:07:98:B2:2D:89:AE:FC:A5:5E:5F:B0:34:1E:F5:12
keyUsage
Digital Signature, Key Encipherment
basicConstraints
CA:FALSE
extendedKeyUsage
TLS Web Server Authentication
certificatePolicies
Policy: 1.3.6.1.4.1.6449.1.2.2.7 CPS: https://sectigo.com/CPS Policy: 2.23.140.1.2.1
authorityInfoAccess
CA Issuers - URI:http://crt.sectigo.com/SectigoPublicServerAuthenticationCADVR36.crt OCSP - URI:http://ocsp.sectigo.com
subjectAltName
DNS:a2b-internet.com, DNS:www.a2b-internet.com
ct_precert_scts
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 : Jan 13 14:03:29.693 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:91:B8:90:D2:F3:A2:31:5B:51:46:F7: 71:B6:AD:98:F8:68:A0:5B:6E:C0:BE:F8:F6:C4:3A:D8: CF:09:59:65:AF:02:20:30:EB:1B:1F:B4:A5:E6:5F:01: 93:55:6E:6B:79:73:AF:13:F8:04:8C:BB:3C:3F:2E:77: 8B:56:CF:7C:B0:0D:6F 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 : Jan 13 14:03:30.186 2026 GMT Extensions: 00:00:05:00:01:60:CB:CC Signature : ecdsa-with-SHA256 30:46:02:21:00:E7:0D:01:ED:0C:83:DE:B3:67:AE:E0: 9D:69:45:BB:A9:A8:58:B2:B7:23:D0:D3:93:C3:4F:41: C8:63:2D:77:26:02:21:00:EA:3B:A0:A3:88:62:A0:79: EE:2D:E7:8C:18:CC:32:E3:49:23:B9:97:E5:4C:E0:56: EE:E1:B8:CA:FD:E9:AD:27 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 59:6E:6C:33:86:94:B2:59:72:A2:56:C8:A0:E8:DD:90: 4A:76:E8:08:3D:DA:87:3B:01:08:38:28:14:3C:EE:59 Timestamp : Jan 13 14:03:29.647 2026 GMT Extensions: 00:00:05:00:00:0D:45:67 Signature : ecdsa-with-SHA256 30:46:02:21:00:E2:CE:D2:0D:2F:D8:67:3A:18:12:2F: 5A:84:DD:F9:89:71:65:08:37:52:FB:99:66:E4:8D:96: 18:C5:A7:16:B4:02:21:00:BF:E2:A5:6D:C5:17:C5:D4: A7:FC:89:E3:3D:0B:6D:21:1B:F7:C5:94:9A:C7:31:BB: 96:63:04:D4:06:B9:E1:6A
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-22T17:51:49+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=GB ST=Greater Manchester L=Salford O=Sectigo Limited CN=Sectigo RSA Domain Validation Secure Server CA
Issuer
C=US ST=New Jersey L=Jersey City O=The USERTRUST Network CN=USERTrust RSA Certification Authority
Valid from
2018-11-02T00:00:00+00:00
Expires
2030-12-31T23:59:59+00:00
Days remaining
1561
Serial (hex)
7D5B5126B476BA11DB74160BBC530DA7
Signature
RSA-SHA384
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

7F:A4:FF:68:EC:04:A9:9D:75:28:D5:08:5F:94:90:7F:4D:1D:D1:C5:38:1B:AC:DC:83:2E:D5:C9:60:21:46:76
Certificate extensions & PEM
authorityKeyIdentifier
53:79:BF:5A:AA:2B:4A:CF:54:80:E1:D8:9B:C0:9D:F2:B2:03:66:CB
subjectKeyIdentifier
8D:8C:5E:C4:54:AD:8A:E1:77:E9:9B:F9:9B:05:E1:B8:01:8D:61:E1
keyUsage
Digital Signature, Certificate Sign, CRL Sign
basicConstraints
CA:TRUE, pathlen:0
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
certificatePolicies
Policy: X509v3 Any Policy Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://crl.usertrust.com/USERTrustRSACertificationAuthority.crl
authorityInfoAccess
CA Issuers - URI:http://crt.usertrust.com/USERTrustRSAAddTrustCA.crt OCSP - URI:http://ocsp.usertrust.com
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US ST=New Jersey L=Jersey City O=The USERTRUST Network CN=USERTrust RSA Certification Authority
Issuer
C=GB ST=Greater Manchester L=Salford O=Comodo CA Limited CN=AAA Certificate Services
Valid from
2019-03-12T00:00:00+00:00
Expires
2028-12-31T23:59:59+00:00
Days remaining
831
Serial (hex)
3972443AF922B751D7D36C10DD313595
Signature
RSA-SHA384
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

68:B9:C7:61:21:9A:5B:1F:01:31:78:44:74:66:5D:B6:1B:BD:B1:09:E0:0F:05:CA:9F:74:24:4E:E5:F5:F5:2B
Certificate extensions & PEM
authorityKeyIdentifier
A0:11:0A:23:3E:96:F1:07:EC:E2:AF:29:EF:82:A5:7F:D0:30:A4:B4
subjectKeyIdentifier
53:79:BF:5A:AA:2B:4A:CF:54:80:E1:D8:9B:C0:9D:F2:B2:03:66:CB
keyUsage
Digital Signature, Certificate Sign, CRL Sign
basicConstraints
CA:TRUE
certificatePolicies
Policy: X509v3 Any Policy
crlDistributionPoints
Full Name: URI:http://crl.comodoca.com/AAACertificateServices.crl
authorityInfoAccess
OCSP - URI:http://ocsp.comodoca.com
-----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.

View certificate JSON

Registration / WHOIS →DNS records →