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

t-systems.at · 80.158.66.24:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
CN=t-systems.at
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-08-25T13:13:21+00:00
Expires
2026-11-23T13:13:20+00:00
Days remaining
57
Serial (hex)
065BC01B2CD2F09CE5CDB51E23724FA31390
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:t-systems.at

SHA-256 fingerprint

9B:87:13:1D:EA:E7:7D:A4:17:4D:0D:C0:FE:5D:F3:CE:12:81:94:57:48:FB:60:4D:E5:83:75:F7:4C:F8:24:A6
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
38:26:DD:B8:DF:8B:6D:89:27:FB:AB:1D:40:29:BA:75:79:F5:23:68
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:t-systems.at
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/17.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : Aug 25 14:11:51.744 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:51:FE:2A:FD:0E:7F:7F:AA:92:60:3B:0E: BA:B3:24:E3:3D:0C:2A:A7:CB:2A:74:F2:39:78:2D:F2: 5E:7B:FD:99:02:20:31:1E:5A:82:F3:99:BB:11:73:00: DE:94:05:4B:A0:1C:A9:7A:1A:D2:01:37:6A:CB:34:95: A6:E6:10:4A:8C:14 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : A8:26:CB:E3:0A:C6:35:12:46:53:3F:E0:65:F1:4F:19: D9:6E:19:08:13:C4:1D:D9:6D:79:00:B3:12:3C:55:27 Timestamp : Aug 25 14:11:52.691 2026 GMT Extensions: 00:00:05:00:24:EB:00:65 Signature : ecdsa-with-SHA256 30:44:02:20:6F:3C:7B:73:F6:3D:33:CF:35:1F:9C:60: BD:ED:98:80:56:2A:55:79:3D:D3:A9:79:DD:09:87:5E: B2:69:ED:45:02:20:11:83:79:8B:33:34:93:E6:EE:0D: 40:B5:A4:91:90:47:EE:E1:FC:2B:AF:80:DE:AC:C5:46: 53:19:F8:A2:02:0F
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-09-27T01:02:22+00:00

Server-presented chain · 2 additional certificates

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
706
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-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YR
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2167
Serial (hex)
F24B6D17F9D9AD7CB1C9FEA78782699F
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

07:26:39:D0:B1:40:D5:BF:FA:E1:6A:D9:C3:F6:CC:60:86:04:06:21:F5:1E:E6:1A:6D:46:A8:91:5C:07:CF:76
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
authorityInfoAccess
CA Issuers - URI:http://x1.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x1.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.

View certificate JSON

Registration / WHOIS →DNS records →