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

techfak.net · 129.70.142.93:443

Verified

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

Subject
CN=techfak.net
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-09-02T11:52:28+00:00
Expires
2026-12-01T11:52:27+00:00
Days remaining
69
Serial (hex)
065C41623A082EED4C66D79627FD686C5748
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.techfak.de, DNS:*.techfak.net, DNS:*.techfak.org, DNS:*.techfak.uni-bielefeld.de, DNS:*.tf.uni-bielefeld.de, DNS:*.tf.unibi.de, DNS:techfak.de, DNS:techfak.net, DNS:techfak.org, DNS:techfak.uni-bielefeld.de, DNS:tf.uni-bielefeld.de, DNS:tf.unibi.de

SHA-256 fingerprint

B4:98:02:EF:50:93:45:A0:BF:62:3F:96:72:C9:5D:B7:22:FE:E8:2B:8F:24:61:38:28:E3:ED:0F:53:26:F6:AC
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
EA:9B:85:0F:B6:24:E4:8F:9F:4C:93:AC:1E:50:66:60:39:BC:24:D9
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:*.techfak.de, DNS:*.techfak.net, DNS:*.techfak.org, DNS:*.techfak.uni-bielefeld.de, DNS:*.tf.uni-bielefeld.de, DNS:*.tf.unibi.de, DNS:techfak.de, DNS:techfak.net, DNS:techfak.org, DNS:techfak.uni-bielefeld.de, DNS:tf.uni-bielefeld.de, DNS:tf.unibi.de
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/73.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D8:09:55:3B:94:4F:7A:FF:C8:16:19:6F:94:4F:85:AB: B0:F8:FC:5E:87:55:26:0F:15:D1:2E:72:BB:45:4B:14 Timestamp : Sep 2 12:50:58.258 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:C8:C1:AF:FD:D0:7B:E3:04:F1:D8:46: 5E:00:B2:BC:68:41:AD:28:AF:6D:63:0D:0B:FE:11:AA: A2:A9:9C:B8:94:02:21:00:E0:6A:85:34:20:27:8E:B6: 5D:46:B3:5E:E9:02:E1:64:66:B8:28:96:67:5F:69:1B: 1C:84:28:DE:74:D2:B4:20 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1A:8B:9D:6B:0F:FE:BF:81:B4:79:39:C6:D2:31:0A:86: D6:D1:02:D4:F0:46:E2:18:2C:9D:E3:5F:5E:26:25:EF Timestamp : Sep 2 12:50:58.368 2026 GMT Extensions: 00:00:05:00:3B:8C:08:29 Signature : ecdsa-with-SHA256 30:45:02:21:00:8B:69:B4:EF:F1:40:ED:C6:F5:37:5C: 60:85:88:C8:2D:DE:1C:B5:A9:BE:BB:C8:DF:04:B0:C5: 4B:FA:F9:13:20:02:20:46:44:9B:8F:E4:5E:0F:A6:FB: 9A:9C:B6:BB:27:5B:68:E0:76:8F:5A:25:58:15:18:9D: BB:2F:FF:C8:C9:23:3C
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES256-GCM-SHA384 · Checked 2026-09-22T20:48:02+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
711
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
2172
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

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