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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

TLSv1.3

cytadel.fr · 178.23.155.160:443

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
The certificate has expired.

Certificate verification failed

Subject
CN=cytadel.fr
Issuer
C=US O=Let's Encrypt CN=R3
Valid from
2023-07-25T20:58:05+00:00
Expires
2023-10-23T20:58:04+00:00
Days remaining
-1109
Serial (hex)
043604F73F0D3A89F6D584A5CEB20B9A2F13
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:cytadel.fr, DNS:cytadel.io, DNS:www.cytadel.io

SHA-256 fingerprint

2A:84:09:1E:D1:46:98:49:05:75:E1:C6:F8:16:16:4A:C7:63:77:5F:B4:7C:34:ED:4C:70:F4:D4:7B:F6:6F:33
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
56:3E:22:A2:EA:80:AD:C3:AC:4C:F4:F7:56:80:E5:89:8F:50:AC:C6
authorityKeyIdentifier
14:2E:B3:17:B7:58:56:CB:AE:50:09:40:E6:1F:AF:9D:8B:14:C2:C6
authorityInfoAccess
OCSP - URI:http://r3.o.lencr.org CA Issuers - URI:http://r3.i.lencr.org/
subjectAltName
DNS:cytadel.fr, DNS:cytadel.io, DNS:www.cytadel.io
certificatePolicies
Policy: 2.23.140.1.2.1
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : B7:3E:FB:24:DF:9C:4D:BA:75:F2:39:C5:BA:58:F4:6C: 5D:FC:42:CF:7A:9F:35:C4:9E:1D:09:81:25:ED:B4:99 Timestamp : Jul 25 21:58:05.831 2023 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:03:C6:FF:4C:28:EB:C4:7D:E1:3A:32:2D: A1:92:28:EA:83:5F:F4:72:89:37:82:CE:35:3A:75:EB: F8:97:FD:40:02:21:00:A5:1A:76:3E:D6:DD:66:1A:23: 4D:54:15:11:26:92:2A:6F:EC:59:B5:79:1F:87:AB:13: 5C:FD:A0:3D:1A:81:25 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 7A:32:8C:54:D8:B7:2D:B6:20:EA:38:E0:52:1E:E9:84: 16:70:32:13:85:4D:3B:D2:2B:C1:3A:57:A3:52:EB:52 Timestamp : Jul 25 21:58:06.355 2023 GMT Extensions: none Signature : ecdsa-with-SHA256 30:43:02:1F:0E:2D:FD:4F:9C:CC:60:C9:FF:6E:4E:CF: 00:90:2A:3B:29:27:EE:F2:7E:3B:70:26:84:12:D5:F4: 32:CC:DA:02:20:5F:A4:B9:CF:08:DF:B6:A6:26:CC:C7: F5:70:E9:C7:4C:C9:A7:3C:25:30:CC:DB:11:E5:B2:7F: 4A:4E:A7:A8:32
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-05T05:48:58+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=R3
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2020-09-04T00:00:00+00:00
Expires
2025-09-15T16:00:00+00:00
Days remaining
-416
Serial (hex)
912B084ACF0C18A753F6D62E25A75F5A
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

67:AD:D1:16:6B:02:0A:E6:1B:8F:5F:C9:68:13:C0:4C:2A:A5:89:96:07:96:86:55:72:A3:C7:E7:37:61:3D:FD
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Client Authentication, TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
14:2E:B3:17:B7:58:56:CB:AE:50:09:40:E6:1F:AF:9D:8B:14:C2:C6
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/
crlDistributionPoints
Full Name: URI:http://x1.c.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1 Policy: 1.3.6.1.4.1.44947.1.1.1
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=Internet Security Research Group CN=ISRG Root X1
Issuer
O=Digital Signature Trust Co. CN=DST Root CA X3
Valid from
2021-01-20T19:14:03+00:00
Expires
2024-09-30T18:14:03+00:00
Days remaining
-766
Serial (hex)
4001772137D4E942B8EE76AA3C640AB7
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

6D:99:FB:26:5E:B1:C5:B3:74:47:65:FC:BC:64:8F:3C:D8:E1:BF:FA:FD:C4:C2:F9:9B:9D:47:CF:7F:F1:C2:4F
Certificate extensions & PEM
basicConstraints
CA:TRUE
keyUsage
Certificate Sign, CRL Sign
authorityInfoAccess
CA Issuers - URI:http://apps.identrust.com/roots/dstrootcax3.p7c
authorityKeyIdentifier
C4:A7:B1:A4:7B:2C:71:FA:DB:E1:4B:90:75:FF:C4:15:60:85:89:10
certificatePolicies
Policy: 2.23.140.1.2.1 Policy: 1.3.6.1.4.1.44947.1.1.1 CPS: http://cps.root-x1.letsencrypt.org
crlDistributionPoints
Full Name: URI:http://crl.identrust.com/DSTROOTCAX3CRL.crl
subjectKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
-----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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